CN100574894C - Spray gun for electrostatic spraying - Google Patents

Abstract

Translated fromChinese

一种适合于使用电阻较小的涂料的静电喷涂的喷枪。在前端外周缘具有向前方突出的圆筒部(36)的筒管(2)的前端中央部安装着涂料喷嘴(24)，设置有将其前面覆盖的空气罩(40)。在空气罩与涂料喷嘴的外周面、圆筒部内周面之间形成图形空气流路(45)，在其流路内安装环状电极(13)。在空气罩的中央部设置雾化空气喷出孔(32)，可插通涂料喷嘴前端部的涂料吐出口(30)。销子状电极(31)穿通涂料吐出口向前方突出。1对角部(39)从空气罩的左右两端部向前方突出，在该角部设置图形空气喷出孔(38)，将销子状电极接地，向环状电极附加直流高电压。

A spray gun suitable for electrostatic spraying with less resistive coatings. A paint nozzle (24) is mounted on the front end center portion of the bobbin (2) having a forwardly protruding cylindrical portion (36) on the outer peripheral edge of the front end, and an air cover (40) covering the front face thereof is provided. A graphic air flow path (45) is formed between the air cover, the outer peripheral surface of the paint nozzle, and the inner peripheral surface of the cylindrical part, and an annular electrode (13) is installed in the flow path. An atomizing air ejection hole (32) is provided in the central part of the air cover, and can be inserted through the paint outlet (30) at the front end of the paint nozzle. The pin-shaped electrode (31) protrudes forward through the paint discharge port. 1 pair of corners (39) protrude forward from the left and right ends of the air cover, and pattern air ejection holes (38) are provided at the corners, the pin-shaped electrodes are grounded, and DC high voltage is applied to the ring electrodes.

Description

Electrostatic coating spray gun

Technical field

The present invention relates to electrostatic coating spray gun, particularly relate to the electrostatic coating spray gun of the aqueous coating that is suitable for using resistance less, electrostatic spraying that metal is coating.

Background technology

In general, in the coating that the electrostatic spraying of car body etc. is used, can be divided into the higher solvent of resistance and be the less aqueous coating (water paint) of coating (oil paint), resistance and be dispersed in metal dust with the metal in coating is coating.Wherein, using less aqueous coating, the metal of resistance is the occasion that coating carries out electrostatic spraying, if directly high voltage is additional to the charge electrodes of the electrostatic spraying gun body that contacts with these coating, electric current can flow to ground connection by coating feed path, coating case.Like this, because of not causing discharge between charge electrodes and coated article, so the coating particle that is atomized can not be charged.

As the conventional art that addresses this problem, a kind of method that coating case and ground connection are carried out the insulation of electric property is for example arranged.Adopt this method, because of high voltage being additional between the charge electrodes and coated article of electrostatic spraying gun body, so can make coating particle charged.But it is, very inconvenient because need a kind of special coating supplementary device that makes when replenishing coating the coating operation interrupt or keep replenishing under the state with the insulation of the electric property of coating case (for example, with reference to patent documentation 1) to the additional high voltage of coating case.

As another solution, have a kind ofly 1 and even a plurality of outer electrode to be set on the radial outside position of electrostatic spraying gun body and, to be called as the outer electrode mode to its additional high-tension mode.This mode can be divided into: use the mode (for example, with reference to patent documentation 2) of swinging atomising head in the coating atomizing in the electrostatic spraying gun body and use compressed-air actuated pneumatic spray regime (for example, with reference topatent documentation 3).Dual mode is not that the coating that additional high-tension outer electrode and resistance is low contacts, so can make coating particle charged under the state of coating case ground connection.Thereby, do not need to be provided with and replenish the special device that coating is used to coating case, can carry out continuous coating.

Yet, when adopting the outer electrode mode, except the electrostatic spraying gun body, also outer electrode to be installed, electrostatic spraying gun is maximized, and, there is high-tension electrode to be present in body exterior because of additional, so very dangerous.Again, also existing the coating particle that is atomized is attached near the outer electrode because of electrostatic force or the problem around the electrostatic spraying gun body.

[patent documentation 1] Japan Patent spy opens the 2002-143730 communique

[patent documentation 2] Japanese patent laid-open 06-134353 communique

[patent documentation 3] Japanese patent laid-open 09-136047 communique

Summary of the invention

The present invention makes under above-mentioned background, its purpose is, provide the aqueous coating that is suitable for using resistance less, electrostatic spraying that metal is coating pneumatic spray regime electrostatic spraying gun promptly, coating case ground connection is sprayed and the compactly designed electrostatic coating spray gun of electrode is not set in body exterior.

Purpose of the present invention realizes by the electrostatic coating spray gun that following feature is provided, promptly, a kind of high voltage that uses makes compressed air-atomized coating electrified, the electrostatic coating spray gun that sprays on coated article, comprising: thebobbin 2 that on the outer peripheral edges of leading section, is formed with forwards outstandingcylindrical portion 36; Leading section, its inside that is installed on thisbobbin 2 has flow path of being coated with 29 and atomizingair stream 33 and has the paint spray nozzle made of insulatingmaterial 24 of coating discharge opening 30 at front end; Theairhood 40 that the front end face of thispaint spray nozzle 24 and describedbobbin 2 is covered, thisairhood 40 is the outer peripheral face of face and describedpaint spray nozzle 24 within it, form space between the inner peripheral surface of describedcylindrical portion 36 as figureair flow circuit 45, this airhood is equipped with at central portion to be inserted logical for described coating discharge opening 30, and be communicated with described atomizingair stream 33, can spray compressed-air actuated atomizingair squit hole 32, around this atomizingair squit hole 32, be equipped with equally and be communicated with described atomizingair stream 33, can spray compressed-air actuated a plurality of assistant figureair squit hole 38a, this airhood has outstanding from both ends, the front end left and right sides, be equipped with and be communicated with 1 acrosscorner 39 that can spray compressed-air actuated figureair squit hole 38 with described figureair flow circuit 45 to oblique inboard the place ahead; From the forwards outstandingpin shape electrode 31 of described coating discharge opening 30; In the space that becomes described figureair flow circuit 45, form theelectrode 13 that ring-type surrounds describedpaint spray nozzle 24, with describedpin shape electrode 31 ground connection, additional dc high voltage between thispin shape electrode 31 and describedelectrode 13.

This occasion, preferably with the vertical direction of the line that is connected described 1 acrosscorner 39 on, at 2 positions leaving about 1/2 radius of thisairhood 40 from the center on describedairhood 40 surfaces, setting runs through the surface and the floating electrode between the back side (floating I electrode) 50 of thisairhood 40, and describedelectrode 13 is formed semi-annular shapes, be mounted to distance between side's electrode tip of the end that makes thiselectrode 13 and described floatingelectrode 50 and equal distance between the opposing party's electrode tip of the other end of thiselectrode 13 and described floatingelectrode 50.

Adopt the electrostatic coating spray gun of structure like this, can use the less aqueous coating of resistance, metal is the electrostatic spraying of coating.Because ofelectrode 13 being accommodated in the inside of spray gun, can make the spray gun miniaturization so compare with outer electrode again.And, because of adding the inside that high-tension electrode 13 is accommodated in spray gun, so can obtain to improve the effect of security.

Again, when using interpolation to be provided with the electrostatic coating spray gun of describedfloating electrode 50 structures, between floatingelectrode 50 andpin shape electrode 31, produce discharge along airhood surface, can obtain to reduce the effect of the amount of the coating particle that is attached to the airhood surface thus.

Another purpose of the present invention realizes by the electrostatic coating spray gun that following feature is provided, promptly, a kind of use high voltage makes compressed air-atomized coating electrified, the electrostatic coating spray gun that on coated article, sprays, with 31 break-through of pin shape electrode be installed on this electrostatic coating spray gun 1 as the front face of thebobbin 2 of body from the central portion ofairhood 40 to the coating discharge opening 30 of outside opening and forwards outstanding, on radially upper-lower position with the describedairhood 40 of thesepin shape electrode 31 clampings, be formed with thebight 40d more outstanding than described coating discharge opening 30,40e, at thisbight 40d, the insulation jacketedelectrode 13a by the insulating material covering surfaces is taken in the inside of 40e, 13b, with describedpin shape electrode 31 ground connection, to ground connection and described insulation jacketedelectrode 13a, additional dc high voltage between the 13b.

Adopt the electrostatic coating spray gun of structure like this, because of the additional high-tension electrode surface of direct current is covered by insulating material, so electric current does not flow between insulation jacketedelectrode 13a, 13b and pin shape electrode 31.Like this, can under the narrower state in insulation jacketedelectrode 13a, 13b and the interval ofpin shape electrode 31, add high voltage.Can nearpin shape electrode 31, particularly produce highfield near its front end thus, can make to be atomized the charged opposite polarity polarity that becomes and insulate jacketedelectrode 13a, 13b of air-atomized coating particle.Charged coating particle along with the conveyance of figure air near coated article, utilize electrostatic force to be sprayed on the coated article.When using this electrostatic coating spray gun under this effect, not only solvent is a coating, and can carry out the less aqueous coating of resistance, metal is the electrostatic spraying of coating.Again, because of not needing the such outer electrode of conventional art, so can form compact spray gun.

Description of drawings

Fig. 1 is the longitudinal section of the spray gun leading section of the 1st embodiment.

Fig. 2 is the longitudinal section of spray gun of the present invention.

Fig. 3 is the front view of front end air cover of the spray gun of the 1st embodiment.

Fig. 4 is the front view that the front end air cover of spray gun is taken off the fore-end of state of the 1st embodiment.

Fig. 5 produces the structure example in loop for high voltage.

Fig. 6 is the longitudinal section of the spray gun leading section of the 2nd embodiment.

Fig. 7 is the front view of front end air cover of the spray gun of the 2nd embodiment.

Fig. 8 is the front view that the front end air cover of spray gun is taken off the fore-end of state of the 2nd embodiment.

Fig. 9 is the stereogram of position relation of each electrode of the spray gun of the 2nd embodiment.

Figure 10 is another stereogram of position relation of each electrode of the spray gun of the 2nd embodiment.

Figure 11 is the longitudinal section of the spray gun leading section of the 3rd embodiment.

Figure 12 is the longitudinal section of the spray gun fore-end of the 4th embodiment.

Figure 13 is the front view of front end air cover of the spray gun of the 4th embodiment.

Figure 14 is the electrical system of the spray gun of explanation the 4th embodiment and the ideograph of effect.

Figure 15 is the front view of front end air cover of the variant embodiment of spray gun of the present invention.

Figure 16 is the front view of front end air cover of another variant embodiment of spray gun of the present invention.

The specific embodiment

In order to describe the present invention more in detail, describe with reference to accompanying drawing.

(the 1st embodiment)

The 1st embodiment of electrostatic coating spray gun of the present invention (being designated hereinafter simply as spray gun) is described below with reference to Fig. 1～Fig. 5.The spray gun of present embodiment is to be that coating is its purpose with main use resistance less aqueous coating or metal as coating.Fig. 2 represents the longitudinal section of spray gun 1 unitary construction of present embodiment, Fig. 1 represents the longitudinal section of its fore-end, Fig. 3 represents the front view of frontend air cover 40 described later, Fig. 4 represents thisairhood 40 is taken off the front view of fore-end of the spray gun 1 of state, and Fig. 5 represents to produce high-tension loop example.

This spray gun 1 as shown in Figure 2, by as the bobbin (body of a gun) 2 of gun body be located at thereafter that thehandle 3 of end constitutes.Bobbin 2 is made of the synthetic resin material of insulating properties, and integral body becomes cylindric.This spray gun 1 is the spray gun that a kind of high voltage produces the loop built in type, and the top inbobbin 2 is taken in and will be produced the integrally molded long grid (カ ス ケ-De) 4 of fore-and-aft direction in required step-up transformer of high voltage and high voltage rectifier loop.

As shown in Figure 5, the required high voltage of electrostatic spraying is produced bycontrol loop 51 and high voltage generation loop 55.Control loop 51 is set near the not shown coating case, has high frequencyelectric source loop 52 and output transformer 53.When source power supply is supplied with in high frequencyelectric source loop 52, at the primary side generation high frequency voltage of theoutput transformer 53 that is connected with its outlet side.The high frequency voltage that is produced is located at the primary side supply that the high voltage in the grid 4 produces the step-up transformer 56 in theloop 55 byfeed cable 54 in spray gun 1.The high frequency voltage that boostedtransformer 56 boosts produces the dc high voltage of 30,000～60,000 V through extraordinarilyvoltage commutation loop 57 rectifications of Cockcroft, John Douglas Te-Wa Erdun type.In addition, the high-tension polarity that is produced can become just (+) or negative (-) with respect to earthing potential by changing the extraordinarily direction of the diode in thevoltage commutation loop 57 of Cockcroft, John Douglas Te-Wa Erdun type.

The dc high voltage that is produced, from the lead-outterminal 6 of grid 4front ends spring 7 by the electric conductivity that is in contact with it, the rear end side of the columnedconductive contact 8 that guiding and the hole that is arranged in thisanterior bobbin 2 screw togather is taken out by anotherelectric conductivity spring 9 from the front ofcontact 8 again.In the front ofspring 9, the cylindric resistance that screws togather with the hole that wears from the front end face ofbobbin 2 is installed keeps body 10.The leading section ofspring 9 is inserted in and is arranged in the distolateral thereafter hole, to inserting thehigh resistance body 11 end application of force inwardly in this hole, the rear end terminal of thehigh resistance body 11 that simultaneously high voltage led.The front end terminal ofhigh resistance body 11 connectsresistance maintenance body 10 from the inner end portion in hole, contacts with the rear end face of the stub of giving prominence to slightly from the front end face ofresistance maintenance body 10 12.At the leading section ofoutstanding stub 12, by welding etc. affixedelectrode 13 described later.Like this, the high voltage that is produced is supplied with toelectrode 13 by thehigh resistance body 11 of electric current restriction usefulness.

Coating, is supplied with to thecoating coupling nipple 15 that is installed onhandle 3 bottoms by coating flexible pipe (not shown) from coating case (not shown), again from itsvalve chamber 21 bycoating pipe 16 guiding paint valves 20.Paint valve 20 is set in theguide hole 18, and thisguide hole 18 wears to rear end side inbobbin 2 from the inner end central portion of therecess 17 of the front end central portion of being located atbobbin 2 and forms.

Paint valve 20 hasvalve chamber 21,pin 22,guide hole 18,valve port 25 and liner 26.The leading section ofpin 22 is coniform, connectsvalve chamber 21 along fore-and-aft direction.Part channeling conduct movably on fore-and-aft direction at the more rear that is positioned atvalve chamber 21 of 18 pairs ofpins 22 of guide hole.Valveport 25 is communicated between the paint spray nozzle described later 24 andvalve chamber 21 that is fixed onpaint valve 20 front ends, and the butt joint of the coniform leading section by makingpin 22 separates to be opened or inaccessible.Liner 26 is installed betweenvalve chamber 21 and theguide hole 18, and the periphery driving fit ofpin 22 becomes the close state of liquid relatively.

Pin 22 in thepaint valve 20, the application of force of the back-movingspring 27 ofbobbin 2 rearward end is located in utilization, always remains the valve state that closes withvalve port 25 obturations, spues to paintspray nozzle 24 to stop the coating of supplying with.Pin 22 only trigger 28 drawn back during just overcome back-movingspring 27 and retreat, withvalve port 25 openings,paint valve 20 becomes out the valve state.Incase paint valve 20 is driven valve, the coating that has supplied in thevalve chamber 21 spues in thepaint spray nozzle 24 that is installed onpaint valve 20 the place aheads.

Leading section atbobbin 2, be formed with therounded installation recess 17 of section of form is cut in its front end face central authorities, install on the interior week ofrecess 17 at this, thepaint spray nozzle 24 that is made of insulating properties synthetic resin material screws togather with end thereafter, fixes from the forwards outstanding form ofrecess 17 is installed with leading section.

Run through the centre bore between the rear and front end face ofpaint spray nozzle 24, be communicated with describedvalve port 25 as being coated with flow path 29.The front end ofpaint spray nozzle 24 is, forms the little excrescence of diameter with the contacted part of the front end that is coated withflow path 29, inserts in the atomizingair squit hole 32 that leads atairhood 40 described later with the state to outside opening as coating discharge opening 30.Coating frompaint valve 20 is supplied with forwards spues from coating discharge opening 30 by being coated withflow path 29.

In coating discharge opening 30, forwards insert highlightedly and be connected with the metal thinner and make and sellsub-shape electrode 31 than its internal diameter.The rear end side ofpin shape electrode 31 forms spiral spring, is accommodated in to be coated with in theflow path 29, utilizes the application of force of this spring, andpin shape electrode 31 is held in forwards outstanding state.In the present embodiment, having used the less aqueous coating of resistance, metal as coating is coating.Metal is made and sold electric conductivity thatsub-shape electrode 31 utilizes its coating and is connected with the electric property of coating case of not shown ground connection, is maintained at earthing potential.

In the inside ofpaint spray nozzle 24, and a plurality of atomizingair streams 33 that are coated withflow path 29 concentric circles configurations form poroid between the rear and front end face that runs through paint spray nozzle 24.The front end of atomizingair stream 33 be communicated with by the ring-type atomizingair stream 33a that the inside surrounded of the front end face ofpaint spray nozzle 24 andairhood 40.

The leading section ofpaint spray nozzle 24 is covered by airhood 40.The front end peripheral part ofpaint spray nozzle 24 towards front, protrude big circular of diameter, thiscyclic lug 34 is chimeric with therecess 35 ofairhood 40 the insides.Under this state,airhood 40, by with from the front end outer peripheral edges ofbobbin 2 stop-nut 37 that screws togather of the outer peripheral face of the outstandingcylindrical portion 36 that forms forwards, fix with the state of pushingpaint spray nozzle 24 to.Its result has formed by the inside ofairhood 40, the outer peripheral face ofpaint spray nozzle 24, the inner peripheral surface ofcylindrical portion 36, the annular spaces that front end face surrounded of bobbin 2.This space utilizes as the installing space of figureair flow circuit 45 andelectrode 13.

Central portion atairhood 40 is equipped with atomizingair squit hole 32, can insert logical described coating discharge opening 30.Atomizingair squit hole 32 is communicated with described ring-type atomizingair stream 33a, atomizing air by atomizingair squit hole 32 interior week and the annular gap between the periphery of coating discharge opening 30 forwards spray.Around atomizingair squit hole 32, be equipped with a plurality of assistant figureair squit hole 38a that are communicated with ring-type atomizingair stream 33a equally, forwards spray as the assistant figure air from atomizingair stream 33 compressed and supplied air.

And, be formed with 1 opposed and forwards outstanding acrosscorner 39 of left and right directions from the surperficial two ends ofairhood 40, on eachbight 39, be formed be communicated with described figureair flow circuit 45 a plurality of (among Fig. 3, about have 2 respectively) figureair squit hole 38, as compressed-air actuated figure air to the ejection of oblique inboard the place ahead.

The compressed air that atomizing air and figure air are used, never illustrated compressed air generator is supplied with to theair hose joint 41 that is installed onhandle 3 bottoms by the pressure-air flexible pipe.By theair flow circuit 42 in thehandle 3, guiding is located at theair valve 43 ofbobbin 2 rearward end to compressed air from this.

Air valve 43 is to being opened and closed by thevalve body 44 compressed and supplied air that move forward and backward withpin 22 one.When openingpaint valve 20,air valve 43 is also driven valve, and whenpaint valve 20 was closed,air valve 43 also closed valve.In caseopen air valve 43, then compressed air is supplied with to ring-type atomizingair stream 33c, the ring-type figureair flow circuit 45 ofpaint spray nozzle 24 rear ends by atomizingair feed path 33b, the figureair feed path 45a that is located in thebobbin 2.

Additional high-tension electrode 13 forms ring-type.Electrode 13 is incorporated in the ring-type figureair flow circuit 45 between the inner peripheral surface ofcylindrical portion 36 of the outer peripheral face ofpaint spray nozzle 24 andbobbin 2 front ends, waits by welding to be fixed in the front end face slightly on the front end ofoutstanding stub 12 that keepsbody 10 from described resistance.In the part ofring electrode 13, the arcuation fixture 47 that is made of insulating materials that is used to prevent to vibrate is installed.The inboard of fixture 47 contacts with the outer peripheral face ofpaint spray nozzle 24, and the outside contacts with the inner peripheral surface ofcylindrical portion 36, limits moving ofelectrode 13, to prevent its vibration.

The following describes the effect of spray gun 1 of the present embodiment of structure like this.When drawing backtrigger 28,paint valve 20 is opened, and the coating of supplying with from joint 15 spues to being coated withflow path 29, transmits from the surface of the coating discharge opening 30distribution shape electrodes 31 ofpaint spray nozzle 24 front ends and the film shape spues.Simultaneously the high voltage to grid 4 in producesloop 55 supply high frequency voltages, is additional toelectrode 13 by the dc high voltage of tens thousand of V of highvoltage rectifier loop 57 generations byhigh resistance body 11.

Becausepin shape electrode 31 utilizes the electric conductivity of coating and ground connection, therefore, produced the powerful electric field that high-tension electrode 13 directions is arranged towards additional from the surface of pin shape electrode 31.Thus, on the surface of thepin shape electrode 31 surperficial coating that transmit, bring out electric charge a large amount of and high voltage polarity oppositepolarity electrode 13 with electric conductivity.When drawingback trigger 28, the compressed air of break-through atomizingair stream 33 by atomizingair squit hole 32 interior week and the close gap between the periphery of coating discharge opening 30, forwards spray as atomizing air.The mist principle is blown in the coating collision of transmitting on the surface of this atomizing air andelectrode 13, utilization makes the coating atomizing.When spraying, also spray as the assistant figure air from assistant figureair squit hole 38a from atomizingair stream 33 compressed and supplied air with this atomizing air.This assistant figure air also can play complementary effect to the atomizing of coating.

The coating particle of atomizing like this, the electric charge of being responded to when keeping withpin shape electrode 31 surperficial contacts is to dispersing in the air.That is the coating particle that, is atomized has with the opposite polarity polarity ofelectrode 13.

On the other hand, to figureair flow circuit 45 compressed and supplied air, effectively spray to oblique inboard the place ahead as the figureair squit hole 38 in thebight 39 of figure air about be located at.This figure air makes the spray pattern of the coating particle of atomizing form the ellipse that is suitable for spraying.In addition, when forming this spray pattern, the assistant figure air that sprays from described assistant figureair squit hole 38a also can play complementary effect.

Coating particle mainly be by this figure air conveyance near coated article.Charged coating particle is in case near coated article, on the surface of the coated article of ground connection, utilizes electrostatic induction and brings out electric charge with the opposite charge polarity of coating particle.Like this, electrostatic force and worked between the opposite polarity electric charge that brings out, coating particle is subjected to the attraction towards coated article.Utilize this attraction and coating particle is sprayed on the coated article surface by the both sides' of the power of blowing of figure air power.Because of the caused attraction of electrostatic force in action, coating particle also raps around to the dorsal part of coated article, is not coating in the face of the dorsal part of the coated article of spray gun 1 also is coated with.Utilize above acting on to carry out electrostatic spraying on the coated article.

In the present embodiment, concentrating power line, becoming highfield, so discharge in the leading section generation ofpin shape electrode 31 sometimes at the front end of pin shape electrode 31.Discharge current flows toelectrode 13 frompin shape electrode 31 front ends by figure air squit hole 38.Utilize this discharge to form the ionization collar region nearpin shape electrode 31 front ends, the coating particle that is atomized is accepted electric charge from this ionization collar region, causes the variation of its quantity of electric charge and polarity.Because of with the charged of electrostatic induction mode and relevant by the caused charged both sides of ion that form of discharge, so the charged mechanism of the coating particle that atomizes is unusual complexity.In any case because quite strong from the figure air of figureair squit hole 38 ejection, so the coating particle that is atomized mainly be by the conveyance power of this figure air conveyance near coated article.And, utilize by the formed attraction of electrostatic force with by the both sides' of the power of blowing of figure air power to be sprayed on the coated article.

Adopt the spray gun 1 of present embodiment, can use the less aqueous coating of resistance, metal is the electrostatic spraying of coating.Because ofelectrode 13 is accommodated in the inside of spray gun 1, can make spray gun 1 miniaturization so compare with the outer electrode mode again.And additional high-tension electrode 13 is accommodated in thebobbin 2 of spray gun 1, so can improve security.

(the 2nd embodiment)

Present embodiment is to the embodiment after aforementioned the 1st embodiment improvement.In the structure of the 1st embodiment,,, produce split pole electric charge on the surface ofairhood 40 withelectrode 13 identical polars so in the synthetic resin material that formsairhood 40, produce split pole because of existing from the highfield ofpin shape electrode 31 to electrode 13.Like this, in the charge particle that is atomized, from by the part of the charged coating particle that breaks away from the formed conveyance air-flow forwards of figure air sometimes by this split pole charge-trapping and attached to the surface of airhood 40.Present embodiment is a kind of embodiment that has carried out improvement in order to prevent coating from going up attached to these airhood 40 surfaces.

Fig. 6 is the longitudinal section of fore-end of the spray gun 1 of present embodiment, and Fig. 7 represents the front view of frontend air cover 40, and Fig. 8 represents thisairhood 40 is taken off the front view of the fore-end of state.The dissimilarity of the structure of present embodiment and the 1st example structure, the shape of onairhood 40, having added 2 floatingelectrodes 50 and having changedelectrode 13 just, other structure is identical.Therefore, same or considerable part mark prosign in the drawings omits its explanation.

Floatingelectrode 50 is on the vertical line of central shaft byairhood 40 and the line that is connected 1 acrosscorner 39, is equipped with 2 on relative central shaft is symmetrical position.The distance of decentre axle is the about 1/2 ofairhood 40 radiuses, on its position, and central axes and connect the surface ofairhood 40 and the back side between install.Front position andairhood 40 surperficial unanimous on the whole, the rear end is also unanimous on the whole with the back of the body surface of airhood 40.Floatingelectrode 50 become not only from electric property ground connection float, but also the state that floats fromelectrode 13.

Electrode 13 in the present embodiment is semi-annular shape as shown in Figure 9.The same with the 1st embodiment, in figureair flow circuit 45, be mounted to the shape that paintspray nozzle 24 is surrounded.Fig. 9 represents the stereogram of the position relation of 13,2 floatingelectrodes 50 of electrode,pin shape electrode 31.

2 floatingelectrodes 50, the central axis ofairhood 40 is in the position of symmetry relation relatively, and the center of arc ofelectrode 13 is also consistent with the central shaft ofairhood 40.Electrode 13 forms semi-annular shape, its twoends 13a, the relative central axis of 13b are in the position of symmetry relation, therefore, the distance between anend 13a ofelectrode 13 and approaching this distolateral side's the floatingelectrode 50a equals theother end 13b ofelectrode 13 and the distance between the opposing party's floatingelectrode 50b.

In the present embodiment, important point is that twoends 13a, the 13b ofelectrode 13 equates with 2 distances between 2 floatingelectrode 50a, the 50b.If these 2 distances equate, the then basic no problem ofelectrode 13 itself then.Like this, as shown in figure 10, be not semi-annular shape yet, but, form its end positions and get final product in the such shape of symmetric position with respect to central axis with bendings such as square band, pole, steel wires.Again, preferably on its two ends, as shown in figure 10 in the face of floatingelectrode 50 forms little projection, perhaps in the face of the shape of floatingelectrode 50 with the fore-end bending.In addition, in the present embodiment, the arcuation fixture 47 that is made of insulating materials is installed also, to prevent the vibration ofelectrode 13.

In the structure of present embodiment, the occasion in that additional high voltage has carried out electrostatic spraying also produces discharge betweenpin shape electrode 31 and floatingelectrode 50a, the 50b and between twoends 13a, the 13b of floatingelectrode 50a, 50b and electrode 13.This occasion, as previously mentioned, because of floatingelectrode 50a andelectrode tip 13a, floatingelectrode 50b equate with distance between theelectrode tip 13b, so the resistance of 2 discharge paths of discharge path bypin shape electrode 31, floatingelectrode 50a,electrode tip 13a and the discharge path bypin shape electrode 31, floatingelectrode 50b,electrode tip 13b equates.Like this, the discharge current by 2 paths equates the electric discharge phenomena of generation same degree substantially.

Discharge between discharge betweenpin shape electrode 31 and the floatingelectrode 50a,pin shape electrode 31 and the floatingelectrode 50b mainly is to transmit on the surface ofairhood 40 and produce.Like this, in case the surface ofairhood 40 produces discharge, this discharge path and be that the coating particle that adheres in the surf zone ofairhood 40 at center will reduce with floatingelectrode 50a, 50b.

Its reason roughly consider to have following some.The 1st, can think that the relation because of floatingelectrode 50a, 50b makes the table ofairhood 40 carry on the back the short circuit of electric property, so do not produce split pole on the synthetic resin material in its vicinity.Thus, because of the surface atairhood 40 does not produce the split pole electric charge, so be not easy to adhere to charged coating particle.In fact, in the 1st embodiment of floatingelectrode 50a, 50b was not installed, finding after spraying stops residually on the surface ofairhood 40 soon had electric charge, but in the present embodiment, does not detect residual charge.

The 2nd, because of making along the near surface of the near surface of its discharge path and floatingelectrode 50a, 50b periphery, the discharge along the surface formed the ionization circle.In case produce the ionization circle, the coating particle that enters this ionization circle will be accepted charged because of its ion.Coating particle after charged repels mutually because of charged polarity is identical.Like this, coating particle just is not easy on the surface attached toairhood 40.

In the present embodiment, the charged mechanism of the coating particle that is atomized is very complicated.After being commonly considered as atomizing soon coating particle because of electrostatic induction with having gone up and the high-tension opposite polarity polarity that is additional to electrode 13.This charged coating particle along with the conveyance of figure air near coated article.But, in its conveyance way, because of the ionization circle that discharge produced on the surface of above-mentionedairhood 40, perhaps be the discharge that produced in the path ofpin shape electrode 31, figureair squit hole 38,electrode 13, perhaps be the relation of ion of emitting from figureair squit hole 38 with the figure air of producing of the discharge of floatingelectrode 50 betweenelectrode 13 because ofairhood 40 inboards etc., make the charged particles amount of coating particle and polarity be subjected to delicate influence.

In fact, can observe by the phenomenon of conveyance near polarity its polarity inversion under the effect of the ejection intensity of figure air of the charged particles of the coating particle the coated article.Yet, near the coating particle that is atomized flying here coated article mainly is to be undertaken by the conveyance power of figure air, sudden coating particle makes the coated article surface of ground connection bring out the electric charge of opposite polarity, and this electric charge that brings out between be sprayed on the coated article under the attraction that produced and the effect by the both sides' of the formed power of blowing of figure air power.

Adopt the spray gun 1 of such present embodiment, the surface alongairhood 40 between floatingelectrode 50 andpin shape electrode 31 produces discharge, can obtain to make the effect of the coating particle amount minimizing that is attached to airhood 40 surfaces thus.Again, the same with the 1st embodiment, because of adding in thebobbin 2 that high-tension electrode 13 is accommodated in spray gun 1,, can also obtain to improve the effect of security so can make the spray gun miniaturization.

(the 3rd embodiment)

Figure 11 represents the longitudinal section of spray gun 1 fore-end of present embodiment.The dissimilarity of the structure of present embodiment and the 2nd embodiment only is not to be provided with pin shape electrode 31.In general, power line is that the part from point, thin part produce mostly, and near the electric-field intensity it is big.If from this point, thinpin shape electrode 31 is forwards given prominence in coating discharge opening 30.Yet, even there is not thispin shape electrode 31, guarantee in earthing potential, so utilize the electrostatic induction can be atomized under electriferous state because of coating itself has electric conductivity.Again, the coating of the export department ofcoating discharge opening 30 and be located at and also produce discharge between the floatingelectrode 50 onairhood 40 surfaces.Thus, equally with the 2nd embodiment carry out electrostatic spraying, can obtain the effect identical with the 2nd embodiment.

(the 4th embodiment)

Figure 12 represents the longitudinal section of spray gun 1 fore-end of present embodiment.Figure 13 represents the front view of fore-end.

The dissimilarity of the structure of present embodiment and the 1st embodiment only is the shape ofelectrode 13 and airhood 40.Other structure is identical.Theairhood 40 of present embodiment is a kind ofly to use the synthetic resin material of insulating properties to form dual cylindric for the front end face side that covers paint spray nozzle 24.It is mounted to the state that the end face that makes itsinner core 40b is pushed on the periphery leading section ofpaint spray nozzle 24 with becoming airtight shape, fixes by the stop-nut 37 that the outer peripheral face with the front endcylindrical portion 36 ofbobbin 2 screws togather.

Become the atomizingair stream 33a of ring-type by the part that the back side surrounded of the coniform leading section ofinner core 40b,paint spray nozzle 24 andairhood 40, form the stream of atomizing air communicatively with the atomizingair stream 33 in the paint spray nozzle 24.Again, between theinner core 40b andurceolus 40h ofairhood 40, be communicated with, formed the stream of figure air with the formed figureair flow circuit 45 in the radial direction outside ofpaint spray nozzle 24.

Axle center at the 40a of front side wall portion ofairhood 40 is equipped with atomizingair squit hole 32, leads in this hole to insert to the state of outside opening inserting the coating discharge opening 30 that is leading to pin shape electrode 31.Atomizingair squit hole 32 is communicated with the atomizingair stream 33a of described ring-type, atomizing air by atomizingair squit hole 32 interior week and the annular gap between the periphery of coating discharge opening 30 forwards spray.Again, around atomizingair squit hole 32, be equipped with a plurality of assistant figureair squit hole 38a that are communicated with ring-typeatomizing air stream 33a equally, forwards spray as the assistant figure air from atomizingair stream 33 compressed and supplied air.

Between theinner core 40b andurceolus 40h of the central shaft that comprises the 40a of front side wall portion, be formed with opposed mutually and forwardsoutstanding bight 40d, 40e at interior above-below direction.On eachbight 40d, 40e, be formed with a plurality of (among Figure 12, respectively having 2 up and down) the figureair squit hole 38 that is communicated with described figureair flow circuit 45, spray to oblique inboard the place ahead as compressed-air actuated figure air.

During spraying, the compressed air by atomizingair stream 33 utilizes the principle of blowing mist to make the coating atomizing that spues from the coating discharge opening 30 ofpaint spray nozzle 24 from atomizingair squit hole 32 and assistant figureair squit hole 38a ejection.With its simultaneously, blow to the coating particle that is atomized from the figure air of figureair squit hole 38 ejections by figureair flow circuit 45, the spray pattern of coating particle is formed the ellipse that is suitable for spraying.

The maximum of the spray gun 1 of present embodiment is characterised in that, be arranged at the inside of described 2bight 40d, 40e of the radially upper-lower position of the 40a of front side wall portion at the standing shape ofairhood 40, taking in insulation jacketedelectrode 13a, 13b by electricproperty insulating materials 13c covering surfaces.On this insulation jacketedelectrode 13a, 13b, byspring 9, bigresistive element 11, thestub 12 additional positive dc high voltages that produceloop 55 generations by described high voltage.The minus side of dc high voltage is by the not shown line of return ground connection of break-through inpower connector 5.

Pin shape electrode 31 contacts with the coating with electric conductivity that the front illustrated, carries out ground connection by coating in the coating case side.Like this, between insulation jacketedelectrode 13a, 13b andpin shape electrode 31, the additional dc high voltage that has high voltage to produce tens thousand of V ofloop 55 generations.

Below with reference to the ideograph of the connection status of electrical system shown in Figure 15, the action and the effect of spray gun 1 of the present embodiment of structure like this is described.

As the explanation that reference Fig. 5 is done the 1st embodiment, produce the dc high voltage thatloop 55 produces 30,000～60,000 V bycontrol loop 51 and high voltage.The dc high voltage that is produced by bigresistive element 11 will insulatejacketed electrode 13a, 13b as side of the positive electrode to and pinshape electrode 31 between additional.From as the insulation jacketedelectrode 13a of positive pole, the power line that 13b sends, most ofly arriveairhood 40 that break-through forms by insulating materials and thepin shape electrode 31 of ground connection.Because of the coating ground connection ofpin shape electrode 31, induce a large amount of negative (-) electric charges so utilize electrostatic induction on the surface ofpin shape electrode 31 by electric conductivity.

Under this state, in case draw back trigger 28, then paintvalve 20 is opened, and the coating in thevalve chamber 21 are supplied with to theflow path 29 that is coated with ofpaint spray nozzle 24, spues from the coating discharge opening 30 ofpaint spray nozzle 24 front ends.Transmitted by the coating distribution shape electrode that spued 31 and flow to the place ahead.Negative electrical charge is brought out on surface at pin shape electrode 31.Because of coating has electric conductivity, so transmit and during flowing to the place ahead, accept negative electrical charge and be with negative electricity frompin shape electrode 31 atdistribution shape electrode 31.

On the one hand, when drawing backtrigger 28,air valve 43 is also opened, and compressed air is supplied with to the atomizingair stream 33 and the figureair flow circuit 45 ofairhood 40 inboards.Forwards spray from atomizingair squit hole 32 and assistant figureair squit hole 38a to atomizingair stream 33 compressed and supplied air, make its atomizing with the coating collision of transmitting on the surface of pin shape electrode 31.When the coating that is atomized contacts with the surface ofpin shape electrode 31 to have the state of charged negative electrical charge become particulate and to dispersing in the air.That is negative electricity on the coating particle band that, disperses.

On the other hand, spray by figureair squit hole 38 the place ahead to figureair flow circuit 45 compressed and supplied air to the 40a of front side wall portion of airhood 40.The coating particle that just has been atomized is along with the air stream conveyance forwards together of this ejection.

But,, concentrate on the fore-end ofpin shape electrode 31 as shown in figure 14 in a large number from the power line that insulation jacketedelectrode 13a, 13b send.Like this, near the electric-field intensity the front end ofpin shape electrode 31 is very big, produces electronics with negative electrical charge and the ion with positive charge behind the air ionization.The electronics that is produced quickens and causes electron avalanche along power line under the effect of highfield, produces a large amount of electronics and cation behind the air ionization.On the other hand, the cation that is produced neutralizes with electrode collide towards negativepin shape electrode 31, but the surface of a large amount of electronics frompin shape electrode 31 is emitted during collision.

Under by the ionization of the caused air of this electron avalanche and the effect of emitting, produce a large amount of electronics near the front end ofpin shape electrode 31 and emit towards periphery from the electronics of pin shape electrode 31.Its result has partly formed the negative ionization collar region that has a large amount of electronics in the front space of the 40a of front side wall portion ofairhood 40.

The coating particle that atomizes under electronegative state is by the conveyance forwards of figure air, by this negative ionization collar region.By the time, coating particle is accepted electronics and further is with negative electricity.

Passed through the coating particle of negative ionization collar region, under the effect of figure air form oval-shaped spray pattern on one side, further conveyance forwards on one side, conveyance is near coated article.Electronegative coating particle is in case near coated article, induces positive charge on the surface of the coated article of ground connection because of electrostatic induction.Like this, electronegative coating particle, and this positive charge that brings out between be subjected to attraction under the effect of the electrostatic force that produced towards coated article.

Utilize these both sides' of the power of blowing of attraction that this static produces and figure air power, coating particle is sprayed on the coated article surface.Except blowing the power of figure air, the attraction that also has static also in action, so coating particle also raps around to the dorsal part of coated article, in the posterior components of the coated article of not facing spray gun 1 also sprayed coating.Utilize above acting on to carry out electrostatic spraying on the coated article.

In the present embodiment, electronegative coating particle might be attached to the surface of the 40a of front side wall portion ofairhood 40 and the surface ofbight 40d, 40e along power line towards insulation jacketedelectrode 13a, 13b.But, from the 40a of front side wall portion ofairhood 40 compressed air ejection forwards forcefully, be suppressed to Min. so the lip-deep coating to the 40a of front side wall portion ofairhood 40 andbight 40d, 40e can be adhered to by figureair squit hole 38 and assistant figureair squit hole 38a.

But the power line that sends from insulation jacketedelectrode 13a, 13b, also oriented foreign side runs through theurceolus 40h ofairhood 40 and the power line that sends.If have this power line, the coating particle that then might make the negative electrical charge that breaks away from from spray pattern moves and is attached to the outer surface of theurceolus 40h ofairhood 40 along this power line.

In order to prevent that this from adhering to, in the spray gun 1 of present embodiment, a compressed-air actuated part set shavingair ejiction opening 37a from the stop-nut 37 that is used for shaving (シ エ-ジ Application グ) air extrusive body is forwards sprayed.Shavingair ejiction opening 37a is provided with a plurality of on the whole circumference of stop-nut 37.Like this, move the coating particle that comes to the surface of theurceolus 40h ofairhood 40 and forwards dispelled, be attached to the surface ofurceolus 40h with prevention by the shaving air.

In the present embodiment, the surface of insulation jacketedelectrode 13a, 13b is covered by insulating material 13c.Thus, electric current does not flow between insulation jacketedelectrode 13a, 13b and pin shape electrode 31.Promptly, electric current no longer producesloop 55 from high voltage and continues to flow toelectrode 13a, 13b, produce the dc high voltage thatloop 55 produces by high voltage, just make between it generation highfield and use for the charging of the static capacity betweenelectrode 13a, 13b and the pin shape electrode 31.Therefore, the load current supply capacity in highvoltage generation loop 55 has any to get final product slightly.The outer electrode mode of enumerating in this point and one of the background technology is made a world of difference.

Electric current is mobile between insulation jacketedelectrode 13a, 13b andpin shape electrode 31, and this just means the interval of can reduce to insulatejacketed electrode 13a, 13b and pin shape electrode 31.Like this, in the spray gun 1 of present embodiment, even low voltage also can generate the advantages of highfields atpin shape electrode 31 peripheries when having than the outer electrode mode.

As previously mentioned, the atomizing of coating mainly is to be undertaken by atomizing air, but should when atomizing, it is generally acknowledged: because of existing highfield between insulation jacketedelectrode 13a, 13b and thepin shape electrode 31 also useful to the electronegative electrostatic force that coating produced that contacts withpin shape electrode 31 to foreign side.

Because attached on the coated article, so electric current flows to pinshape electrode 31 from coated article, the electric current that flows intopin shape electrode 31 passes and returns coated article to the earth electronegative coating particle frompin shape electrode 31 sudden backs.That is, produced electromotive force, that is to say and to generate electricity along this path.For producing the required energy of this electromotive force is not to produceloop 55 from high voltage but supplied with by compressed air.This electricity generating principle is similar to the electricity generating principle of Wei Muhusi electrostatic induction machine (Wimshurst influence machine).

As described above, adopt the spray gun 1 of present embodiment, can be suppressed under the minimal state under with the state of coating case ground connection and with near coating particle adhering to spray gun 1 front end, implementing to have used the less aqueous coating of resistance, metal is the electrostatic spraying of coating.If use distribution cable, be the electrostatic spraying of coating also then applicable to using the big solvent of resistance withpin shape electrode 31 ground connection again.

(variant embodiment)

The present invention is not limited to the above embodiments, also can implement following distortion or expansion.

Among the 4th embodiment, insulation jacketedelectrode 13a, 13b are accommodated in thebight 40d ofairhood 40, the inside of 40e, but also can under the state of the surperficial electric property insulation of will insulatejacketed electrode 13a, 13b, be mounted to forwards outstanding shape frombight 40d, 40e.Even so, also can carry out electrostatic spraying certainly with previous embodiments ground.

Again, among the 4th embodiment, insulation jacketedelectrode 13a, 13b are installed in the radially upper-lower position with 31 clampings of pin shape electrode, but also can be installed on position to the left and right, footpath.Like this, the spray pattern of coating particle and the occasion of previous embodiment are slightly different, do not change but can carry out the electrostatic spraying this point equally.

Again, among the 4th embodiment, insulation jacketedelectrode 13a, 13b total have 2, but the footpath at clampingpin shape electrode 31 also can be provided with forwardsoutstanding bight 40f, 40g on the position to the left and right, also can take in insulation jacketedelectrode 13f, 13g (with reference to Figure 15) by the insulating material covering surfaces in thisbight 40f, 40g.

Again, among the 4th embodiment, also can replaceaforesaid bight 40d, 40e and form andpin shape electrode 31 surrounded andoutstanding annulus 29a, the ring-type insulating bag is installed in thisannulus 29a be coveredelectrode 13d (with reference to Figure 16).Like this, has the effect that strengthens near the electric-field intensity thepin shape electrode 31 and enlarge the negative ionization collar region.

Among the 4th embodiment,,pin shape electrode 31 is carried out ground connection as minus side to insulation jacketedelectrode 13a, the additional positive high voltage of 13b again.But also opposite polarity.When polarity was opposite, coating had positive charge atomizing, formed positive ionization collar region at the periphery of pin shape electrode 31.And coating particle is sprayed on the coated article with the state of positively charged, carries out electrostatic spraying with aforesaid embodiment the samely.

Again, among the 4th embodiment thatpin shape electrode 31 is outstanding to the place ahead ofairhood 40 from the coating discharge opening 30 ofpaint spray nozzle 24, do not implement but can have under the situation of thispin shape electrode 31 yet.Under this occasion, though the formation of the ionization collar region inairhood 40 the place aheads is more weak slightly than aforesaid embodiment, but the coating that spues fromcoating discharge opening 30 atomizes electronegatively, by the conveyance of figure air to coated article, so also can carry out electrostatic spraying in such an embodiment.

This occasion is formed with the fore-end at least ofpaint spray nozzle 24 front ends ofcoating discharge opening 30, also can use the conductive material of metal species to form.This occasion is compared with the occasion that fore-end is formed by insulating materials has the charged effect of the coating particle of promotion.

Again, among the 1st, the 2nd, the 4th embodiment,pin shape electrode 31 comes ground connection by the coating with electrical conductivity, but also can use distribution cable withpin shape electrode 31 ground connection.Like this, can make ground connection firm, increase security, and be applicable to that also the big solvent of resistance is the electrostatic spraying of coating.

Utilizability on the industry

In sum, electrostatic coating spray gun of the present invention is suitable for the aqueous coating, the gold that use resistance littler Genus is the spray gun that the electrostatic spraying of coating is used.

Claims (9)

1. an electrostatic coating spray gun (1), it is compressed air-atomized coating electrified to use high voltage to make, and applies on coated article, it is characterized in that, comprising:

On the outer peripheral edges of leading section, be formed with the bobbin (2) of forwards outstanding cylindrical portion (36);

Leading section, the inside that is installed on this bobbin has flow path of being coated with (29) and atomizing air stream (33) and has the paint spray nozzle made of insulating material (24) of coating discharge opening (30) at front end;

The airhood (40) that the front end face of this paint spray nozzle (24) and described bobbin (2) is covered, this airhood (40) is the outer peripheral face of face and described paint spray nozzle (24) within it, form space between the inner peripheral surface of described cylindrical portion (36) as figure air flow circuit (45), this airhood is equipped with for described coating discharge opening (30) slotting logical at central portion, and be communicated with described atomizing air stream (33), can spray compressed-air actuated atomizing air squit hole (32), around this atomizing air squit hole, be equipped with equally and be communicated with described atomizing air stream (33), can spray compressed-air actuated a plurality of assistant figure air squit holes (38a), this airhood has outstanding from both ends, the front end left and right sides, be equipped with and be communicated with 1 across corner (39) that can spray compressed-air actuated figure air squit hole (38) with described figure air flow circuit (45) to oblique inboard the place ahead;

From the forwards outstanding pin shape electrode (31) of described coating discharge opening (30);

Formation surrounds the electrode (13) of described paint spray nozzle (24) annularly in the space that becomes described figure air flow circuit (45),

With described pin shape electrode (31) ground connection, additional dc high voltage between ground connection and described electrode (13).

2. electrostatic coating spray gun as claimed in claim 1, it is characterized in that, with the vertical direction of the line that is connected described 1 across corner (39) on, at 2 positions leaving about 1/2 radius of this airhood (40) from the center on described airhood (40) surface, be provided with the surface and the floating electrode between the back side (50) that run through this airhood (40), and described electrode (13) is formed semi-annular shape, be mounted to distance between side's electrode tip of the end that makes this electrode (13) and described floating electrode (50) and equal distance between the opposing party's electrode tip of the other end of this electrode (13) and described floating electrode (50).

3. electrostatic coating spray gun, it is compressed air-atomized coating electrified to use high voltage to make, and applies on coated article, it is characterized in that,

With pin shape electrode (31) from the central portion break-through of the airhood (40) of the front face of the bobbin as body (2) that is installed on this electrostatic coating spray gun (1) to the coating discharge opening (30) of outside opening and forwards outstanding, on radially upper-lower position with the described airhood (40) of this pin shape electrode (31) clamping, be formed with the bight (40d more outstanding than described coating discharge opening (30), 40e), at this bight (40d, insulation jacketed electrode (the 13a by the insulating material covering surfaces is taken in inside 40e), 13b), with described pin shape electrode (31) ground connection, to ground connection and described insulation jacketed electrode (13a, additional dc high voltage 13b).

4. electrostatic coating spray gun as claimed in claim 3, it is characterized in that, with the footpath of the described airhood (40) of described pin shape electrode (31) clamping to the left and right on the position, also be provided with the bight (40f, 40g) more outstanding than described coating discharge opening (30), the insulation jacketed electrode (13f, 13g) by the insulating material covering surfaces is also taken in the inside of (40f, 40g) in this bight, also additional dc high voltage between ground connection and described insulation jacketed electrode (13f, 13g).

5. electrostatic coating spray gun as claimed in claim 3, it is characterized in that, replace described bight (40d, 40e) with insulation jacketed electrode (13a, 13b), periphery in described airhood (40), formation surrounds described pin shape electrode (31) and the annulus (29a) more outstanding than described coating discharge opening (30), take in ring-type insulation jacketed electrode (13d) by the insulating material covering surfaces in the inside of this annulus (29a), with described pin shape electrode (31) ground connection, additional dc high voltage between ground connection and this ring-type insulation jacketed electrode (13d).

6. as each described electrostatic coating spray gun of claim 1 to 5, it is characterized in that, described pin shape electrode (31) is not set, form the part that constitutes described coating discharge opening (30) but use conductive material instead, use has the coating of electric conductivity as described coating, additional dc high voltage between ground connection and described insulation jacketed electrode.

7. as each described electrostatic coating spray gun of claim 1 to 5, it is characterized in that, described pin shape electrode (31) is not set, and is to use coating, additional dc high voltage between ground connection and described insulation jacketed electrode as described coating with electric conductivity.

8. as each described electrostatic coating spray gun of claim 1 to 5, it is characterized in that, use distribution cable described pin shape electrode (31) ground connection.

9. as each described electrostatic coating spray gun of claim 3 to 5, it is characterized in that, near the front end of the bobbin as body (2) of electrostatic coating spray gun, Outboard Sections at the urceolus of described airhood (40) is provided with shaving air ejiction opening (37a), and the urceolus surface from this shaving air ejiction opening (37a) along described airhood (40) forwards sprays compressed air.

Images