CN102631732A - Low-resistance piston component of syringe - Google Patents

Abstract

The invention discloses a low-resistance piston component of a syringe, which comprises a piston and a connector. The piston is provided with a piston inner hole, and the connector is sleeved in the piston inner hole; at least the front end of the piston is provided with a recess; the connector is provided with a press plate corresponding to the recesses and a neck corresponding to the piston inner hole; the press plate is provided with a conical peripheral surface with the large outer end and the small inner end, and the diameter of the outer end of the press plate is larger than that of a front port of each recess; the depth of each recess is equal to the thickness of the press plate; the length difference between the connector and the piston is equal to the depth of each recess; and a lip is arranged on the outer peripheral edge of each end, with the corresponding recess, of the piston. Due to expansion of air pressure in cavities at front and rear ends of the piston during pushing and pulling and squeezing of the press plate, the piston is adaptive to the pressure of a hole wall in a jacket, and push-and-pull resistance of the syringe is reduced.

Description

A kind of syringe lower resistance piston component

Technical field

The present invention relates to a kind of injection device, particularly relate to a kind of lower resistance piston component of syringe, it cooperates the formation injection with low resistance with syringe jacket and push rod.

Background technology

Syringe is a kind of medical apparatus and instruments commonly used.Usually syringe comprises overcoat and piston push rod.In order to obtain a better seal effect, piston need carry out tighter applying with outer casing inner wall.Consequently operator's operation is very difficult, has greatly increased the labor intensity of user.Notification number is that the Chinese invention patent of CN100435871C discloses a kind of injection with low resistance, comprise the injection stack shell and in stack shell, slide push away the fluid column plug, piston is O-ring seal, the end face of sealing ring is provided with a circle open slot along its circumferencial direction; Piston fixing device has gomphosis part that is arranged on the sealing ring top and the support component that is arranged on the sealing ring below; The edge of gomphosis part is provided with a circle and corrects the flange that is embedded in the sealing ring end face open slot down, and support component is fixed on the gomphosis part below with sealing ring.Adopt the syringe of this structure; Sealing ring can squeeze to hold and rise big or resilience is dwindled with the change of cylindrical shell inner air pressure, and the contact surface between it and injection cylinder inwall will change with the change of cylindrical shell inner air pressure, makes syringe piston with this kind sealing ring; Its sensitivity is higher; Cylinder internal pressure one changes, and sealing ring will squeeze to open and rise big or resilience is dwindled, thereby reaches the purpose of lower resistance, strong sealing.Because the piston of this syringe is to adopt a circle open slot and a gomphosis part on it to realize.Gomphosis part also inwardly struts when piston is outwards strutted, makes the endoporus of piston tighten the periphery at push rod.Therefore, the syringe of this piston structure can be locked with the piston fastening when push rod spurs, and inserts also no longer makes piston outwards strut, and can not reach the sealing with stack shell.

Summary of the invention

The technical problem that the present invention will solve provides a kind of syringe lower resistance piston component; It improves through the structure to this assembly; Make syringe sealing load of piston and overcoat when push rod promotes depend on the pressure in the overcoat ante-chamber; Therefore,, syringe has less resistance when slowly promoting.And the piston assembly structure that adopts a union joint to cooperate with piston makes push rod when pulling, and piston only outwards struts with overcoat and produces effectively sealing, and is same, the speed when sealing pressure depends on the push rod pulling.Therefore, when user slowly spurs push rod, has less resistance.Thereby utilize syringe of the present invention can realize alleviating the purpose of the labor intensity of user.

Above-mentioned technical problem of the present invention mainly is able to solve through following technical proposals: a kind of syringe lower resistance piston component comprises the piston that is provided with a piston inner hole and is set in the union joint in the said piston inner hole; At least the front end at said piston is provided with a depression; Said union joint is provided with the pressing plate of a corresponding said depression and the cervical region of corresponding said piston inner hole; Said pressing plate is provided with the little circular cone side face in big the inner, outer end, and the outer end diameter of pressing plate is greater than the front port diameter of said depression; The degree of depth of said depression equals the thickness of said pressing plate; The length difference of said union joint and said piston equals the degree of depth of said depression; Be provided with at said piston on the neighboring of female ends and be provided with a lip limit.Through the air pressure distending and the pressing plate extruding of piston front and back end chamber when the push-and-pull, make the pressure of the overcoat inner hole wall of piston self adaptation and syringe, reduced the push-and-pull resistance of syringe.

Kill in order to make the depression on the effective extrusion piston front end of pressing plate and to prevent pressing plate and cave in to push, said depression is the rounding frustum, and the coning angle of this depression is less than the coning angle of said pressing plate, and its differential seat angle is 5～15 degree.

As further optimal technical scheme, on said piston other end, be provided with an end face bulge loop; The height of said end face bulge loop is less than the degree of depth of said depression.When push rod promotes, be used for the sealing with push rod, and make union joint promote lower platen from depression, to deviate from, piston is made the self adaptation distending, realize the lower resistance injection by the pressure of piston nose chamber at push rod.

As further optimal technical scheme, said lip cross section comprises near the segmental arc of said piston nose face with away from the flat segments of said piston nose face; The angle of the outer peripheral face of said flat segments and said piston is 120～160 degree.Through the lip setting of this structure, make piston when promoting, have more consistent pressure with the overcoat inner hole wall with pulling.

In order further to strengthen the sealing of union joint and piston, be provided with at least one sealing bulge loop that contact with said neck seal in the said piston inner hole.

As further optimal technical scheme, said union joint rear end is provided with an axial connecting hole, is provided with an internal projecting ring in the connecting hole; The injection rod head end of said syringe be provided with one with the outer bulge loop of said internal projecting ring clamping.Through this interface arrangment, push rod can more easily snap in the union joint, realizes the push pull maneuver in the piston its external sleeve.

Technical scheme of the present invention adopts depression and the pressing plate on the union joint on the piston nose, realizes to piston when the push-and-pull and the squeeze pressure self adaptation of overcoat inner hole wall realization syringe lower resistance in use.Simultaneously, through the structure optimization of lip, make syringe when promoting, have more consistent squeeze pressure with pulling action.

Description of drawings

Fig. 1 is for comprising syringe construction sketch map of the present invention.

Fig. 2 is a structural representation of the present invention.

Fig. 3 is structure of piston sketch map among the present invention.

Fig. 4 is the structural representation of union joint among the present invention.

Fig. 5 is the structural representation of overcoat among the present invention.

Fig. 6 is the structural representation of push rod among the present invention.

Wherein, overcoat 1, ante-chamber 101, ante-chamber end face 1011, back cavity 102, push rod 2, connectingportion 201,outer bulge loop 202,omoplate portion 203, fracture mouthfuls 204, piston 3,depression 301,depression side face 3011,depression port 3012,lip 302,segmental arc 3021,flat segments 3022, pistoninner hole 303,sealing bulge loop 304, endface bulge loop 305, depression cone angle alpha, union joint 4, pressingplate 401, pressingplate side face 4011, pressingplate end face 4012, pressing plate cone angle beta,cervical region 402, connectinghole 403,internal projecting ring 404.

Pass through embodiment below, and combine accompanying drawing, do further bright specifically technical scheme of the present invention.

The specific embodiment

Referring to Fig. 1 and Fig. 2, a kind of syringe lower resistance piston component, it is used for matching used with it overcoat 1 and forms injection with low resistance with the push rod that is connected with piston component 2.Wherein, piston component comprises piston 3 and is set in the union joint 4 in the piston 3.Piston component and overcoat 1 endoporus are dynamically connected as sealed sliding, form ante-chamber 101 that is positioned at the piston component front end and the back cavity 102 that is positioned at the piston component rear end in its external sleeve 1 endoporus.

Referring to Fig. 3 and Fig. 4, piston 3 is set on thecervical region 402 of union joint 4 through the intermediary pistoninner hole 303 of piston.Be provided with adepression 301 at piston 3 head ends, on the neighboring of piston 3 these female ends, be provided with a lip 302.Be provided with sealingbulge loop 304 in two roads at pistoninner hole 303 near recess, on piston 3 rear end faces, be provided with endface bulge loop 305 one near pistoninner hole 303 places.Thisdepression 301 is provided with thedepression side face 3011 of a circular cone, and its depression cone angle alpha is 50 degree.

The front end of union joint 4 is apressing plate 401, iscervical region 402 in the rear end ofpressing plate 401, in the middle ofcervical region 402, is a connectinghole 403, is provided with aninternal projecting ring 404 near mouth end place in the connecting hole 403.On pressingplate 401 peripheries of union joint 4, be provided with a pressing plate side face 4011.This pressingplate side face 4011 is a conical surface, is provided with a pressing plate cone angle beta, and this pressing plate cone angle beta is 60 degree.

Depression port 3012 diameters ofdepression 301 are slightly less than the diameter before the union joint pressing plate 401.Union joint 4 is set in the pistoninner hole 303 throughcervical region 402, is dynamically connected as sealed sliding through the sealing bulge loop in the pistoninner hole 303 304.Thepressing plate 401 of union joint 4 is engaged in thedepression 301 of piston 3.Because the somewhat larger in diameter ofpressing plate 401 front ends is in the cave in diameter of 301 ports of piston; And the pressing plate cone angle beta of pressingplate side face 4011 is greater than the depression cone angle alpha ofdepression side face 3011, so the pressingplate side face 4011 ofpressing plate 401 contacts withdepression port 3012; And when under union joint 4 drives, doing axially-movable; Pressingplate side face 4011 extrudingdepressions 301 make piston 3 near the outside distending of the outer peripheral face of female ends, makelip 302 and overcoat 1 inner hole wall form sealing.

Flat segments 3022 after the cross section of thelip 302 of piston comprises thesegmental arc 3021 that is positioned at piston 3 front ends and is right after segmental arc.Thisflat segments 3022 is 140 degree with the angle of piston 3 outer peripheral faces.When piston component promotes under push rod 2 promotes, because thislip 302 only depends on the pressure distending in the ante-chamber 101; And piston component is in push rod 2 effect down during pulling, andpiston lip 302 mainly is the extruding through 401 pairs ofdepressions 301 of pressing plate, and its pressure is often greater than the pressure of piston component when the promotion.Therefore, thelip 302 of this structure can make piston component no matter promoting all have consistent pressure when still spurring, be implemented in the syringe that push-and-pull all has lower resistance.

Referring to Fig. 5, its external sleeve ante-chamber 101 has an ante-chamber end face 1011, is provided with an injection outlet in the middle of the end face.This ante-chamber end face 1011 is the conical surface of a big cone angle.Front end at union joint 4 also is provided with a pressingplate end face 4012, and this pressingplate end face 4012 is provided with a conical surface that cooperates with ante-chamber end face 1011.After push rod 2 was promoted forward, the pressing plate end face of union joint 4 4012 was fitted with the ante-chamber end face 1011 of overcoat 1, realized injection or in order to discharge the air in the overcoat ante-chamber 101.

Referring to Fig. 6, the cross section of push rod 2 is cross, is provided with a connectingportion 201 at head end, is provided with one in the position after a while of connectingportion 201 and fractures mouthfuls 204.This connectingportion 201 comprises the hemispherical head structure in the connectinghole 403 that can insert union joint 4, on this connectingportion 201, is provided withbulge loop 202 outside.These connectingportion 201 cross sections also are cross, andouter bulge loop 202 is alternate four parts.Push rod 2 is connected with union joint 4 withinternal projecting ring 404 cooperations in union joint 4 connectingholes 403 through theouter bulge loop 202 on this connecting portion 201.Be provided with anomoplate portion 203 in the rear end of connectingportion 201, when promoting in push rod 2 its external sleeve 1 with piston 3 on endface bulge loop 305 offset the formation end face seal.Syringe is after using, and the push rod that can fracture through the mouth 204 that fractures on the push rod 2 prevents the repeated use of syringe.

Syringe in use; Through promoting push rod 2 piston component is moved forward along overcoat 1 inner hole wall, owing in ante-chamber 101, have air, the air pressure that produces when piston component moves is extruding indepression 301; Pistonlip 302 and overcoat 1 inner hole wall are adjacent to, form sealing.Because the sealing load of thislip 302 and overcoat 1 inner hole wall is from the air pressure of ante-chamber 101, therefore, make mobile in piston component its external sleeve 1 inner hole wall have less resistance.And when extracting action through push rod 2 pulling piston components; Push rod 2 is throughinternal projecting ring 404 andouter bulge loop 202 pulling union joints 4; Make thepressing plate 401 extrudingdepressions 301 on the union joint 4; Form effective sealing with the piston recess, simultaneously,lip 302 outside distendings and overcoat 1 inner hole wall on the piston 3 form effective sealing.The degree oflip 302 outside distendings depends on the extruding degree of 401 pairs ofdepressions 301 of pressing plate.Therefore, the resistance of slower then this piston component of speed and overcoat 1 inner hole wall is just more little.Pressure depends on the translational speed in the piston component its external sleeve 1.

The foregoing description is in order more to be expressly understood the present invention; Not as a kind of restriction to right of the present invention; Under the prerequisite that does not break away from aim of the present invention; Various variations can be arranged, and all these will be included within the scope of this claim the conspicuous modification of said those skilled in the art.

Claims (10)

1. a syringe lower resistance piston component is characterized in that: comprise the piston that is provided with a piston inner hole and be set in the union joint in the said piston inner hole; At least the front end at said piston is provided with a depression; Said union joint is provided with the pressing plate of a corresponding said depression and the cervical region of corresponding said piston inner hole; Said pressing plate is provided with the little circular cone side face in big the inner, outer end, and the outer end diameter of pressing plate is greater than the front port diameter of said depression; The degree of depth of said depression equals the thickness of said pressing plate; The length difference of said union joint and said piston equals the degree of depth of said depression; Be provided with at said piston on the neighboring of female ends and be provided with a lip limit.

2. lower resistance piston component according to claim 1 is characterized in that: said depression is the rounding frustum, and the coning angle of this depression is less than the coning angle of said pressing plate, and its differential seat angle is 5～15 degree.

3. lower resistance piston component according to claim 1 and 2 is characterized in that: on said piston other end, be provided with an end face bulge loop; The height of said end face bulge loop is less than the degree of depth of said depression.

4. lower resistance piston component according to claim 1 and 2 is characterized in that: said lip cross section comprises near the segmental arc of said piston nose face with away from the flat segments of said piston nose face; The angle of the outer peripheral face of said flat segments and said piston is 120～160 degree.

5. lower resistance piston component according to claim 3 is characterized in that: said lip cross section comprises near the segmental arc of said piston nose face with away from the flat segments of said piston nose face; The angle of the outer peripheral face of said flat segments and said piston is 120～160 degree.

6. lower resistance piston component according to claim 1 and 2 is characterized in that: be provided with at least one sealing bulge loop that contact with said neck seal in the said piston inner hole.

7. lower resistance piston component according to claim 3 is characterized in that: be provided with at least one sealing bulge loop that contact with said neck seal in the said piston inner hole.

8. lower resistance piston component according to claim 4 is characterized in that: be provided with at least one sealing bulge loop that contact with said neck seal in the said piston inner hole.

9. lower resistance piston component according to claim 5 is characterized in that: be provided with at least one sealing bulge loop that contact with said neck seal in the said piston inner hole.

10. lower resistance piston component according to claim 5 is characterized in that: said union joint rear end is provided with an axial connecting hole, is provided with an internal projecting ring in the connecting hole; The injection rod head end of said syringe be provided with one with the outer bulge loop of said internal projecting ring clamping.

Images