CN103234499A - Device and method for monitoring electrode displacement in resistance spot welding and resistance spot-welding equipment. - Google Patents

Abstract

The invention discloses a device for monitoring electrode displacement. The device comprises an upper tool arm, a lower tool arm, two displacement sensors and a controller. One end of the upper tool arm is fixed on a fixing and holding portion of a top electrode, and the other end of the upper tool arm extends to a welding equipment substrate; one end of the lower tool arm is fixed on a fixing and holding portion of a bottom electrode, and the other end of the lower tool arm extends to the welding equipment substrate; the displacement sensors are arranged along the height directions of the tool arms at intervals on the other end portion of the upper tool arm and/or the lower tool arm so as to acquire height displacements of the other end at a position corresponding to the upper tool arm and the lower tool arm; and the controller receives the height displacements collected by the displacement sensors to acquire electrode displacement variations. By the device for monitoring electrode displacement, detection precision and convenience of the electrode displacement can be improved effectively. On the basis, the invention further provides resistance spot-welding equipment and a method for monitoring electrode displacement applying the monitoring equipment.

Description

The monitoring device of electrode displacement, method and resistance spot welding equipment in the resistance spot welding

Technical field

The present invention relates to the welding parameter monitoring method of welding technology field, particularly the monitoring device of electrode displacement, method and resistance spot welding equipment in a kind of resistance spot welding.

Background technology

As everyone knows, in resistance spot welding process, electrode displacement refer to upper/lower electrode that nugget causes when in forming process the thermal expansion displacement taking place from displacement variable, it is one of ideal parameters of reflection nugget quality in the resistance spot welding monitoring parameter that its value is defined as.Obviously, obtain the evaluation that electrode displacement variable quantity accurately directly has influence on the nugget quality.

Traditional thermal expansion displacement monitoring method is the moving displacement that only detects top electrode, i.e. the displacement of cylinder action.This monitoring method can effectively be avoided the interference between displacement sensing apparatus and the welded piece, but this method is not considered the displacement movement of bottom electrode in the pinpoint welding procedure, be the displacement of the bottom electrode that causes of the distortion of horn, so the relative displacement between detected electrode displacement and the fict upper/lower electrode.

In addition, there is the researcher single displacement transducer to be installed in an end of frock arm, be connected with the soldering turret upper/lower electrode by its other end after prolonging the frock arm, and by the relation between the prior calibration setup electrode force of scale lower sensor detected value and the actual value (scale).Yet this electrode displacement monitoring method can be avoided the interference between displacement sensing apparatus and the welded piece equally, but this method is not considered the soldering turret distortion that the dynamic change of electrode force causes in the pinpoint welding procedure, detects error thereby exist; And when welding machine or electrode force arrange when changing, the detected value of electrode displacement needs again accepted scale to proofread and correct, and is not suitable for the actual conditions that electrode force changes.

In view of this, demand urgently looking for another way and develop the detection technique of electrode displacement in a kind of resistance spot welding, on the basis of evading the interference of displacement sensing apparatus and welded piece, can effectively overcome the detection error that the dynamic change because of electrode force causes, improve the convenience that electrode displacement detects simultaneously greatly.

Summary of the invention

At above-mentioned defective, the technical matters that the present invention solves is, the monitoring device of electrode displacement in a kind of resistance spot welding is provided, to promote accuracy of detection and the convenience thereof of electrode displacement.On this basis, the present invention also provides a kind of resistance spot welding equipment of this monitoring device of application and the monitoring method of electrode displacement.

The monitoring device of electrode displacement in the resistance spot welding provided by the invention comprises frock arm, down frock arm, two displacement sensing apparatus and controller; Wherein, a described end of going up the frock arm is fixed in the holding parts of top electrode, and its other end extends to the welding gear matrix; A described end of frock arm down is fixed in the holding parts of bottom electrode, and its other end extends to the welding gear matrix; Along the length direction of frock arm, two described displacement sensing apparatus are arranged at intervals at described frock arm and/or described the other end of frock arm down of going up, to obtain the described height displacement amount that goes up frock arm and following frock arm corresponding position of the other end; Described controller receives the height displacement amount that two described displacement sensing apparatus are gathered, and obtains the electrode displacement variable quantity.

Preferably, two displacement sensing apparatus are specially two laser displacement sensors and a laser reflecting curtain; Wherein, along the length direction of frock arm, two described laser displacement sensors are arranged at intervals at described the other end of frock arm down; Described laser reflecting curtain is arranged at described the other end of going up the frock arm of two described laser displacement sensor tops.

Preferably, two displacement sensing apparatus are specially two laser displacement sensors and a laser reflecting curtain; Wherein, along the length direction of frock arm, two described laser displacement sensors are arranged at intervals at described the other end of going up the frock arm; Described laser reflecting curtain is arranged at described the other end of frock arm down of two described laser displacement sensor belows.

Preferably, two displacement sensing apparatus all adopt magnetostrictive displacement sensor or optical displacement sensor or contact grating displacement sensor.

Preferably, described upward frock arm and described frock arm down be arranged in parallel, and vertical with electrode place direction.

Resistance spot welding equipment provided by the invention comprises matrix and is arranged at upper and lower electrode on the described matrix; The monitoring device that also comprises electrode displacement in the foregoing resistance spot welding.

The monitoring method of electrode displacement in the resistance spot welding provided by the invention adopts foregoing monitoring device, and described monitoring method comprises the steps:

A. according to described monitoring device, determine first distance b between two displacement sensing apparatus, and the described displacement sensor device of nearly electrode side is to the second distance a between the electrode;

B. gather the height displacement amount that goes up frock arm and following frock arm corresponding position in real time by two described displacement sensing apparatus: the first height displacement amount Δ d that first displacement sensing apparatus obtains₁The second height displacement amount Δ d with the acquisition of second displacement sensing apparatus₂

C. determine the variation delta d of described electrode displacement by following formula₀, and output:

$\mathrm{\Δ}{d}_0=\frac{\mathrm{b\Δ}{d}_1+\mathrm{a\Δ}{d}_1-\mathrm{a\Δ}{d}_2}{b}.$

Preferably, in the steps A, described second distance a and first distance b are along vertical electrode place direction and form.

Preferably, among the step C, the variation delta d of described electrode displacement_cThe output of employing display.

During practical application, along with depressing of top electrode before the welding, the last frock arm that is fixed in its holding parts moves down in the lump.In the welding process, nugget is grown up when the thermal expansion displacement takes place, upper and lower electrode and corresponding upper and lower frock arm thereof from, upper and lower distance between electrodes then changes, meanwhile, the first height displacement amount Δ d that obtains of two laser displacement sensors₁With the second height displacement amount Δ d₂Also corresponding changing; Controller receives the height displacement amount that two described displacement sensing apparatus are gathered, and can obtain the electrode displacement variable quantity.

Compare with traditional detection technique, the displacement sensing apparatus of this programme and welded piece can not interfere in welding process equally, and its electrode displacement variable quantity obtains the height displacement amount based on two laser displacement sensors of matrix side and determines, that is to say, the present invention has considered the welding gear matrix distortion that the dynamic change of electrode force causes, has effectively controlled the measuring error that the dynamic change of electrode force may cause.In addition, adopt controller to obtain to determine to need not the conversion relation between prior calibration measurements value and the actual value in the process of this electrode displacement variable quantity, have higher convenience.

Description of drawings

Fig. 1 is the synoptic diagram of electrode displacement monitoring device in the resistance spot welding described in the embodiment;

Fig. 2 is the trapezoidal schematic diagram that concerns the potential electrode displacement described in the embodiment.

Among Fig. 1-Fig. 2:

C type soldering turret 10, top electrode 11, bottom electrode 12, last frock arm 21, following frock arm 22, controller 23, first laser displacement sensor 24, second laser displacement sensor 25, laser reflecting curtain 26.

Embodiment

Core of the present invention provides a kind of monitoring device of electrode displacement, so as in resistance spot welding process the accurate variable quantity of detecting electrode displacement, guarantee accurately to estimate the nugget quality.

Being without loss of generality, is that example specifies present embodiment below in conjunction with Figure of description with C type soldering turret, that is, be elaborated as the welding gear matrix with C type soldering turret 10; Same as the prior art, its top electrode 11 links to each other by the open side of holding parts with C type soldering turret respectively with bottom electrode 12, so that welding.

See also Fig. 1, this figure is the assembly relation synoptic diagram of the described electrode displacement monitoring device of present embodiment and resistance spot welding equipment.

As shown in the figure, this monitoring device mainly is made of two frock arms, two displacement transducers and controller.Wherein, an end of last frock arm 21 is fixed in the holding parts of top electrode 11, and its other end extends to the welding gear matrix; One end of following frock arm 22 is fixed in the holding parts of bottom electrode 12, and its other end also extends to the welding gear matrix.Wherein, two displacement sensing apparatus are arranged at intervals at the other end of frock arm 21 and following frock arm 22 along the length direction of frock arm, with the last frock arm of the acquisition other end and the height displacement amount of following frock arm corresponding position, that is to say, set up short transverse displacement relation between matrix side and the electrode side by last frock arm 21 and following frock arm 22.The height displacement amount of two displacement sensing apparatus collections exports controller 23 to, thereby obtains the accurate electrode displacement variable quantity in the welding process.

Need explanation to be, for ease of clear briefly bright its principle of work, with two upper and lower being oppositely arranged as preferred version of electrode, in theory, also can be set in a surface level, be oppositely arranged by two electrodes according to concrete arts demand in this programme.Should be appreciated that applied in the middle of this paper " on ", the noun of locality such as D score do not constitute the restriction to technical scheme.

Obviously, in the middle of the annexation of upper and lower frock arm and respective electrode, its fixed position is more more accurate near the respective electrode testing result; Last frock arm 21 and following frock arm 22 be arranged in parallel, and vertical with electrode place direction, can further improve the precision of testing result equally.Along with the depressing of top electrode 11 before the welding, the last frock arm 21 that is fixed in its holding parts moves down in the lump, and after the electrode force loading, soldering turret deforms, and the last frock arm 21 that two displacement sensing apparatus are measured and the distance between following frock arm 22 other ends are respectively: d₁And d₂, between top electrode 11 and the bottom electrode 12 apart from d₀Constitute trapezoidal relation, please in the lump referring to Fig. 2, this relational expression (1) is as follows:

$d_0=\frac{b{d}_1+a{d}_1-a{d}_2}{b}...\left(1\right)$

Wherein, d₀Be upper and lower distance between electrodes, d₁Be the measured value of first displacement sensing apparatus, d₂Be the measured value of second displacement sensing apparatus, a is the distance between first displacement sensing apparatus and the bottom electrode 22, and b is the distance between second displacement sensing apparatus and first displacement sensing apparatus.

In the welding process, nugget is grown up when the thermal expansion displacement takes place, and upper and lower electrode and corresponding upper and lower frock arm thereof are from, upper and lower distance between electrodes d₀Then change.Simultaneously, actual electrode force changes, and corresponding dynamic deformation takes place soldering turret, causes two displacement sensing apparatus measured value d₁And d₂Also change, this moment according to following relational expression (2) can obtain between the upper/lower electrode apart from d₀Changing value, i.e. real electrode displacement variable quantity;

$\mathrm{\Δ}{d}_0=\frac{\mathrm{b\Δ}{d}_1+\mathrm{a\Δ}{d}_1-\mathrm{a\Δ}{d}_2}{b}...\left(2\right)$

Wherein, Δ d₀, Δ d₁, Δ d₂Be respectively d₀, d₁, d₂Variable quantity.

Obviously, during actual the use, the displacement sensing apparatus of this programme and welded piece can not interfere in welding process equally, can overcome the measuring error that the dynamic change because of electrode force causes in real time, compared with prior art, need the conversion relation between prior calibration measurements value and the actual value in the time of can also saving single displacement sensor.

In addition, for the variation of the height displacement in the elongated end welding process that detects frock arm 21 and following frock arm 22, can adopt multi-form displacement transducer.As shown in the figure, two displacement sensing apparatus comprise first laser displacement sensor 24, second laser displacement sensor 25 and laser reflecting curtain 26 in this programme, wherein, first laser displacement sensor 24 and second laser displacement sensor 25 are arranged at intervals at down the other end that extends to the welding gear matrix of frock arm 22 along the length direction of frock arm; Laser reflecting curtain 26 is arranged at the other end that extends to the welding gear matrix of the last frock arm 21 of two laser displacement sensors 24,25 tops.

In the course of work, first laser displacement sensor 24, second laser displacement sensor 25 are launched light beam respectively to laser reflecting curtain 26, and the reception folded light beam, and then determine that by analog-and digital-processing of circuit and microprocessor analysis real-time height displacement changes.The principle of work of this laser displacement sensor is same as the prior art, can be configured based on the commercially available prod, so this paper repeats no more.

Certainly, the set-up mode of two laser displacement sensors also can reverse configuration.Namely, two laser displacement sensors are arranged at intervals at the other end of frock arm 21 along the length direction of frock arm, correspondingly, the laser reflecting curtain is arranged at the other end of the following frock arm 22 of two laser displacement sensor belows, and the height displacement that can carry out upper and lower frock arm equally changes.

What specify is, two displacement sensing apparatus for detection of the height displacement in the elongated end welding process of last frock arm 21 and following frock arm 22 can also adopt magnetostrictive displacement sensor or optical displacement sensor or contact grating displacement sensor; Wherein, the contact grating displacement sensor has anti-strong electromagnetic ability.Similarly, the principle of work of these two kinds of sensors is same as the prior art, also can be configured based on the commercially available prod, and this paper repeats no more.

The monitoring device of electrode displacement, present embodiment also provides a kind of resistance spot welding equipment, specifically sees also in the lump referring to Fig. 1 in aforementioned resistance spot welding.Main composition and the annexation of this resistance spot welding equipment are same as the prior art, comprise matrix and are arranged at upper and lower electrode on the matrix; Difference is that the resistance spot welding equipment that present embodiment provides disposes foregoing electrode displacement monitoring device.

In addition, present embodiment also provides a kind of monitoring method of application of aforementioned electrode displacement monitoring device, comprises the steps:

A. according to described monitoring device, determine first distance b between two displacement sensing apparatus, and the displacement sensor device of nearly electrode side is to the second distance a between the electrode;

B. gather the height displacement amount that goes up frock arm 21 and following frock arm 22 corresponding positions in real time by two displacement sensing apparatus: the first height displacement amount Δ d that first displacement sensing apparatus 24 obtains₁The second height displacement amount Δ d with 25 acquisitions of second displacement sensing apparatus₂

C. determine the variation delta d of described electrode displacement by following formula₀, and output:

$\mathrm{\Δ}{d}_0=\frac{\mathrm{b\Δ}{d}_1+\mathrm{a\Δ}{d}_1-\mathrm{a\Δ}{d}_2}{b}.$

In this programme, the variation delta d of this electrode displacement₀The output of employing display, the directly perceived demonstration; Also can directly export the judging unit of nugget quality to, and then obtain the evaluation of relevant nugget quality automatically.

Obviously, this second distance a and first distance b are along vertical electrode place direction and form, and can obtain testing result relatively accurately.

In summary, the electrode displacement variable quantity that this programme detection obtains obtains the height displacement amount based on two laser displacement sensors of matrix side and determines, take into full account the welding gear matrix distortion that the dynamic change of electrode force causes, effectively controlled the measuring error that the dynamic change of electrode force may cause.In addition, adopt controller to obtain to determine to need not the conversion relation between prior calibration measurements value and the actual value in the process of this electrode displacement variable quantity, have higher convenience.

The above only is preferred implementation of the present invention, does not constitute the restriction to protection domain of the present invention.Any any modification of doing within the spirit and principles in the present invention, be equal to and replace and improvement etc., all should be included within the claim protection domain of the present invention.

Claims (9)

1. the monitoring device of electrode displacement in the resistance spot welding is characterized in that, comprising:

Last frock arm, the one end is fixed in the holding parts of top electrode, and its other end extends to the welding gear matrix;

Following frock arm, the one end is fixed in the holding parts of bottom electrode, and its other end extends to the welding gear matrix;

Two displacement sensing apparatus are arranged at intervals at described frock arm and/or described the other end of frock arm down of going up along the length direction of frock arm, to obtain the described height displacement amount that goes up frock arm and following frock arm corresponding position of the other end; With

Controller receives the height displacement amount that two described displacement sensing apparatus are gathered, and obtains the electrode displacement variable quantity.

2. the monitoring device of electrode displacement in the resistance spot welding according to claim 1 is characterized in that, two displacement sensing apparatus are specially:

Two laser displacement sensors are arranged at intervals at described the other end of frock arm down along the length direction of frock arm; With

One laser reflecting curtain is arranged at described the other end of going up the frock arm of two described laser displacement sensors tops.

3. the monitoring device of electrode displacement in the resistance spot welding according to claim 1 is characterized in that, two displacement sensing apparatus are specially:

Two laser displacement sensors are arranged at intervals at described the other end of going up the frock arm along the length direction of frock arm; With

One laser reflecting curtain is arranged at described the other end of frock arm down of two described laser displacement sensors belows.

4. the monitoring device of electrode displacement in the resistance spot welding according to claim 1 is characterized in that, two displacement sensing apparatus all adopt magnetostrictive displacement sensor or optical displacement sensor or contact grating displacement sensor.

5. according to the monitoring device of electrode displacement in each described resistance spot welding in the claim 1 to 4, it is characterized in that described upward frock arm and described frock arm down be arranged in parallel, and vertical with electrode place direction.

6. resistance spot welding equipment comprises matrix and is arranged at upper and lower electrode on the described matrix; It is characterized in that, also comprise the monitoring device as electrode displacement in each described resistance spot welding in the claim 1 to 5.

7. the monitoring method of electrode displacement in the resistance spot welding is characterized in that, adopts as each described monitoring device in the claim 1 to 5, and described monitoring method comprises the steps:

A. according to described monitoring device, determine first distance b between two displacement sensing apparatus, and the described displacement sensor device of nearly electrode side is to the second distance a between the electrode;

B. gather the height displacement amount that goes up frock arm and following frock arm corresponding position in real time by two described displacement sensing apparatus: the first height displacement amount Δ d that first displacement sensing apparatus obtains₁The second height displacement amount Δ d with the acquisition of second displacement sensing apparatus₂

C. determine the variation delta d of described electrode displacement by following formula₀, and output:

$\mathrm{\Δ}{d}_0=\frac{b{\mathrm{\Δd}}_1+\mathrm{a\Δ}{d}_1-\mathrm{a\Δ}{d}_2}{b}.$

8. the monitoring method of electrode displacement in the resistance spot welding according to claim 7 is characterized in that, in the steps A, described second distance a and first distance b are along vertical electrode place direction and form.

9. the monitoring method of electrode displacement in the resistance spot welding according to claim 7 is characterized in that, among the step C, and the variation delta d of described electrode displacement₀The output of employing display.