CN111452119B

CN111452119B - Pin clamping device

Info

Publication number: CN111452119B
Application number: CN202010269863.4A
Authority: CN
Inventors: 文铁琦; 黎勇军; 姜华
Original assignee: Shenzhen Hans CNC Technology Co Ltd
Current assignee: Shenzhen Hans CNC Technology Co Ltd
Priority date: 2020-04-08
Filing date: 2020-04-08
Publication date: 2022-03-08
Anticipated expiration: 2040-04-08
Also published as: CN111452119A

Abstract

The invention relates to the field of positioning pin clamps, in particular to a pin clamping device, which comprises: the clamping device comprises a clamping seat assembly and an inclined wedge block, wherein the clamping seat assembly is provided with a clamping groove, the inclined wedge block is arranged on the clamping groove in a sliding mode and is provided with a clamping surface, a limiting part capable of abutting against the side surface of a pin is arranged at the clamping end of the clamping groove, the inclined wedge block is pressed to the clamping end under the action of external force, and the clamping surface is pressed towards the pin to the limiting part to clamp the pin; the sliding direction of the inclined wedge block is perpendicular to the moving direction of the PCB, the clamping surface and the moving direction of the inclined wedge block are arranged in a beta degree, and beta is larger than or equal to 30 degrees and smaller than or equal to 60 degrees. The movement direction of the inclined wedge block is limited to be perpendicular to the movement direction of the PCB, so that the influence of inertia force on the inclined wedge block can be effectively reduced, and the clamping effect of the pin is ensured; and then through set up the clamping face on the tapered wedge, and establish the tapered wedge card between pin and centre gripping groove through external force promptly, can further improve the effect of centre gripping.

Description

Pin clamping device

Technical Field

The invention relates to the field of positioning pin fixtures, in particular to a pin clamping device.

Background

With the continuous development of technology, the market competition of the PCB is more and more intense, and the requirement of customers on the PCB drilling machining precision is more and more rigorous. In the process of processing PCB materials, a clamping and positioning device is generally adopted to clamp and position a positioning pin on the materials. In order to improve the efficiency, production enterprises mostly adopt a plurality of layers of PCB boards to be matched with pins for processing, when a drill bit drills holes from top to bottom, the vertical posture of pin clamping is very important, and if the pins are inclined, the hole position precision of the PCB boards among the layers is influenced. In the same enterprise, for the needs of efficiency and management, only one specification of positioning pins is generally used, such as a typical pin with the diameter of 3.175X15.8, if the more plates are stacked in one processing, the shorter the length reserved for clamping by the clamping device is, and the heavier the weight of the processing material is, the larger the reciprocating inertia force is generated in the process of sudden start and stop of the workbench. Not only influences the precision of location of pin in clamping device, also can lead to the condition emergence that the pin drops. Patent ZL201210424336.1 provides an air clamp and opens and prevents slow-witted method, system and air clamp controlling means, and patent ZL201320373015.3 provides a pneumatic clamping device, all does not solve the problem of locating pin centre gripping gesture on the material.

Accordingly, the prior art is yet to be improved and developed.

Disclosure of Invention

In view of the defects of the prior art, the invention aims to provide a pin clamping device, which solves the problem that the existing pin clamping device cannot solve the problem that a pin is unstable and loosens in the movement process of the device, so that the clamping effect is poor.

The technical scheme of the invention is as follows:

the invention provides a pin clamping device, which is used for clamping a pin to be in a vertical posture so as to position a PCB (printed circuit board), and comprises: the clamping device comprises a clamping seat assembly and an inclined wedge block, wherein the clamping seat assembly is provided with a clamping groove, the inclined wedge block is arranged on the clamping groove in a sliding mode and is provided with a clamping surface, a clamping end of the clamping groove is provided with a limiting part capable of abutting against the side surface of a pin, the inclined wedge block is pressed to the clamping end under the action of external force, and the clamping surface is pressed to the limiting part of the pin to clamp the pin; the sliding direction of the inclined wedge block is perpendicular to the moving direction of the PCB, the clamping surface and the moving direction of the inclined wedge block are arranged in a beta degree, and beta is larger than or equal to 30 degrees and smaller than or equal to 60 degrees.

Further preferred embodiments of the present invention are: the pin clamping device further comprises a power assembly used for driving the inclined wedge block to slide on the clamping groove, the inclined wedge block is pressed to the clamping end under the driving of the power assembly, and the clamping surface is pressed towards the pin to the limiting portion so as to clamp the pin.

Further preferred embodiments of the present invention are: the clamping surface is a curved surface with a convex middle part.

Further preferred embodiments of the present invention are: one end of the wedge block is also provided with a notch for containing dust and processing scraps, and the notch is arranged on the lower side of the clamping surface.

Further preferred embodiments of the present invention are: the beta is 45 degrees.

Further preferred embodiments of the present invention are: the limiting part is a right-angle end face.

Further preferred embodiments of the present invention are: the power assembly comprises a tapered wedge shifting fork which is rotatably arranged on the clamping seat assembly and is used for driving the tapered wedge block to move, and a driving cylinder which is rotatably connected with one end of the tapered wedge shifting fork; the other end of the wedge shifting fork is movably connected with the wedge block through a limiting shaft and a waist-shaped hole, one of the waist-shaped hole and the limiting shaft is arranged on the wedge shifting fork, and the other end of the waist-shaped hole and the limiting shaft is arranged on the wedge block; when the limiting part is matched with the wedge block to clamp the pin, the normal line of the arc contact of the inner wall of the waist-shaped hole and the limiting shaft is arranged at an alpha degree with the motion direction of the wedge block, wherein the alpha is more than 0 degree and less than 15 degrees.

Further preferred embodiments of the present invention are: the clamping seat assembly comprises a mounting plate, a guide cover plate arranged on the mounting plate and a fixed block arranged at one end of the guide cover plate; the clamping groove comprises a guide groove and a limiting groove arranged at one end of the guide groove; the limiting groove is formed in the fixing block, the guide groove is formed in the guide cover plate, and the limiting portion is arranged on the limiting groove.

Further preferred embodiments of the present invention are: the alpha is 10 degrees.

Further preferred embodiments of the present invention are: the pin clamping device further comprises a spring for providing clamping force, one end of the spring is fixed on the mounting plate, and the other end of the spring is fixed on the wedge shifting fork.

Further preferred embodiments of the present invention are: the pin clamping device also comprises a fixed strip arranged on the mounting plate, a movable strip matched with the fixed strip to clamp the pin, a first driving rod and a second driving rod used for driving the movable strip to be far away from or close to the fixed strip, and a connecting rod connected with the first driving rod and the second driving rod; the first driving rod and the second driving rod are rotatably arranged on the mounting plate, and the second driving rod is rotatably connected with the other end of the driving cylinder.

The invention has the beneficial effects that: the movement direction of the inclined wedge block is limited to be perpendicular to the movement direction of the PCB, so that the influence of inertia force on the inclined wedge block can be effectively reduced, and the clamping effect of the pin is ensured; and then through set up the clamping face on the tapered wedge, and establish the tapered wedge card between pin and centre gripping groove through external force promptly, can further improve the effect of centre gripping.

Drawings

FIG. 1 is an exploded view of a pin holder assembly according to an embodiment of the invention;

FIG. 2 is a schematic structural view of a pin clamping device according to an embodiment of the present invention;

FIG. 3 is a cross-sectional view of FIG. 2;

FIG. 4 is a partial exploded view of a pin holder assembly of an embodiment of the present invention;

FIG. 5 is a force analysis diagram of a pin clamping device according to an embodiment of the present invention;

FIG. 6 is a partial perspective view of a pin clamping device of an embodiment of the present invention;

FIG. 7 is a schematic structural view of a sprag according to an embodiment of the invention;

FIG. 8 is a schematic view of a pin clamp of an embodiment of the present invention;

FIG. 9 is a first schematic view of a pin clamp (non-curved surface) according to an embodiment of the present invention;

FIG. 10 shows a pin clamp (non-curved) of an embodiment of the invention in accordance with a second aspect.

Detailed Description

The present invention provides a pin clamping device, which will be described in further detail below with reference to the accompanying drawings and examples in order to make the objects, technical solutions and effects of the present invention clearer and clearer. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

A pin clamping device according to an embodiment of the present invention is used for clamping a pin 5 in a vertical posture to position a PCB (not shown in the drawings), and referring to fig. 1 to 10, the pin clamping device includes: the clamping device comprises a clamping seat assembly 1 provided with a clamping groove 2 and an inclined wedge block 3 which is arranged on the clamping groove 2 in a sliding mode and is provided with a clamping surface 31, wherein a limiting part 21 capable of abutting against the side surface of a pin is arranged at the clamping end of the clamping groove 2, the inclined wedge block 3 is pressed to the clamping end under the action of external force, and the clamping surface 31 is pressed towards the pin 5 to the limiting part 21 so as to clamp the pin 5; the sliding direction of the wedge 3 is perpendicular to the moving direction of the PCB, the clamping surface 31 and the moving direction of the wedge 3 are arranged in a beta degree, wherein beta is more than or equal to 30 degrees and less than or equal to 60 degrees.

The inclined wedge block 3 is clamped between the pin 5 and the upper wall surface of the clamping groove 2.

The movement direction of the inclined wedge block 3 is limited to be perpendicular to the movement direction of the PCB, namely the loosening direction of the inclined wedge block 3 is limited to be perpendicular to the movement direction of the PCB, so that the influence of the inertia force of the movement of the PCB on the inclined wedge block 3 can be effectively reduced, and the clamping effect of the pin 5 is ensured;

through set up clamping face 31 on tapered wedge 3 again, and establish tapered wedge 3 card between pin 5 and centre gripping groove 2 through external force promptly, can realize pasting tight fit between clamping face 31, spacing portion 21 and the pin 5, in PCB board motion process, even external force appears discontinuously, pin 5 can not become flexible yet, guarantees the effect of centre gripping.

Further, by limiting the value of β to 30 ° to 60 °, the effect of holding and fixing can be improved. Wherein, the beta is 45 degrees, and the best fixing effect is achieved. In another embodiment, a matching inclined surface for clamping can be added on the wedge 3 and the clamping groove 2, so that the clamping effect of the wedge 3 can be further improved.

Further, the pin clamping device further comprises a power assembly 4 used for driving the wedge 3 to slide on the clamping groove 2, the wedge 3 is pressed to the clamping end under the driving of the power assembly 4, and the clamping surface 31 is pressed to the pin 5 to the limiting portion 21 to clamp the pin 5. Through increasing power component 4, can compress tightly drive tapered wedge 3 to the exposed core, realize the function of 3 fastening dowel 5 of tapered wedge, convenient and fast, fixed effectual.

Further, as shown in fig. 8, the clamping surface 31 is a curved surface with a convex middle part. In actual production, all machined parts have form and position errors, when the clamping surface 31 is a straight surface and the machining precision is poor, line contact cannot be guaranteed, and the contact conditions shown in fig. 9 and 10 may occur, wherein the contact points are a or B respectively. When the inertial force generated by the material changes direction (the PCB board is reciprocated), the pin 5 may shake, resulting in inaccurate positioning and even a situation where the pin 5 falls out of the pin holder. Through setting up clamping face 31 for the bellied curved surface in middle part, can effectually reduce the machining precision requirement of clamping face 31, the effectual clamping face 31 slope that prevents to lead to because of machining error guarantees the clamping effect.

Further, as shown in fig. 7, one end of the wedge 3 is further provided with a notch 32 for accommodating dust and machining debris, and the notch 32 is disposed below the clamping surface 31. Be used for holding the processing piece and the dust that appear in the course of working through increasing a breach, can effectual reduction processing piece and dust to the influence of pin 5 location, guarantee the centre gripping effect of pin 5.

Further, as shown in fig. 4 and 6, the stopper 21 is a right-angled end surface. Two faces through the right angle end face and the clamping face 31 clamp the pin 5 tightly, the pin 5 can be fixed from three points, and the fixing device has the characteristics of good fixing effect, simple structure, low processing cost and the like. In other embodiments, the limiting portion 21 may be provided as an arc-shaped groove adapted to the pin 5, and the positioning and clamping functions may also be achieved.

Further, the clamping seat assembly 1 comprises a mounting plate 11, a guide cover plate 12 arranged on the mounting plate 11, and a fixing block 13 arranged at one end of the guide cover plate 12; the clamping groove 2 comprises a guide groove 22 and a limiting groove 23 arranged at one end of the guide groove 22; the limiting groove 23 is disposed on the fixing block 13, the guide groove 22 is disposed on the guide cover plate 12, and the limiting portion 21 is disposed on the limiting groove 23. In this embodiment, the clamping seat assembly 1 is configured as the mounting plate 11, the guide cover plate 12, and the fixing block 13, so that the wedge 3 can be conveniently mounted.

In addition, the wedge 3 can rub against the guide groove 22, the limiting groove 23 and the pin 5 during operation. Wherein, the contact surface (the spacing groove 23 and the wedge block 3) of the clamping pin 5 is very small, so the local stress is very large and the abrasion is easy, the local heat treatment improves the hardness of the contact part (the spacing part 21 and the clamping surface 31) with the pin 5, the abrasion can be greatly reduced, thereby ensuring the vertical posture of the pin 5. The friction between the guide groove 22 and the mounting plate 11 with the wedge 3 is negligible due to the large contact area, and even if the friction is worn, the contact point position with the pin 5 is not changed due to the wedging effect and the convex curved surface of the clamping surface 31, so that the heat treatment of the guide groove 22 is not needed, and the production cost can be effectively reduced.

Further, one end of the wedge 3 close to the clamping surface 31 is further provided with a limiting protrusion 33, and by adding the limiting protrusion 33, the wedge 3 can be prevented from sliding away from the guide groove 22, and the stability of the device is ensured.

Further, the power assembly 4 comprises a wedge fork 41 rotatably arranged on the clamping seat assembly 1 and used for driving the wedge block 3 to move, and a driving cylinder 42 rotatably connected with one end of the wedge fork 41; the other end of the wedge shifting fork 41 is movably connected with the wedge 3 through a limiting shaft 61 and a waist-shaped hole 62, one of the waist-shaped hole 62 and the limiting shaft 61 is arranged on the wedge shifting fork 41, and the other is arranged on the wedge 3; the driving cylinder 42 drives the wedge shifting fork 41 to rotate, so that the wedge block 3 can be driven to perform clamping and loosening actions, and the wedge shifting fork is simple in structure, convenient and fast.

Further, when the limiting part 21 is matched with the wedge 3 to clamp the pin 5, the normal line of the arc contact of the inner wall of the waist-shaped hole 62 and the limiting shaft 61 and the motion direction of the wedge 3 are arranged in an angle of alpha, wherein the angle of alpha is more than 0 degrees and less than 15 degrees. In the actual machining process, due to the machining process, a notch (point O) appears at the connecting part of the guide cover plate 12 and the fixed block 13, and the oblique wedge 3 rotates clockwise around the point O after being loosened. According to the invention, the normal line of the arc contact between the inner wall of the waist-shaped hole 62 and the limiting shaft 61 is limited to be arranged at an angle alpha with the movement direction of the wedge 3, and alpha is more than 0 degree and less than 15 degrees, so that an anticlockwise force can be applied to the wedge 3, the stability of the wedge 3 is ensured, and the clamping effect of the pin 5 can be ensured.

Further, α is 10 °. The force of the wedge fork 41 on the pin 5 is F1. When α is 10 degrees, F1y ═ F1 ═ sin80 ° -0.985F 1. F1x ═ F1 ═ sin10 ° -0.174F 1. The horizontal clamping force of the wedge 3 is thus almost equal to the reaction force of the wedge fork 41 (1 ≈ 0.985) each time the clamping pin 5 is clamped, and moreover a comparatively large pressure F1x of the wedge 3 against the clamping groove 2 is generated. From the force analysis in fig. 5 it can be seen that after the wedge 3 has wedged the clamping pin 5, the moment experienced by the wedge 3 is such that it is necessarily located against the inner wall of the clamping groove 2, thus eliminating the play of the structure. The loosening direction of the wedge 3 is perpendicular to the moving direction of the workbench, when the pin clamping device moves with the workbench in a reciprocating high-acceleration mode, the inertia force generated by the processed material is converted into the pressure (component force of F2) of the wedge 3 on the clamping groove 2, the friction force between the wedge 3 and the clamping groove 2 is greatly increased, and the wedge 3 is more difficult to loosen rightwards. In fact, the friction force between the wedge block 3 and the clamping groove 2 is very large (clamping) due to the very large internal stress generated by wedging, and the clamping effect is not changed after the air cylinder unloads air pressure, so that the clamping effect of the clamping pin 5 can be ensured even if the air pressure inside the air cylinder fluctuates or even is suddenly cut off in the PCB processing process, and the clamping reliability can be improved by the structure.

Further, as shown in fig. 2 and 7, the pin clamping device further comprises a spring 7 for providing a clamping force, wherein one end of the spring 7 is fixed on the mounting plate 11, and the other end of the spring 7 is fixed on the wedge yoke 41. Through increasing a spring 7 and providing the clamp force, can guarantee the stability of centre gripping, the effectual prevention drives that the pin 5 that actuating cylinder gas break leads to is not hard up. Wherein, the spring 7 can be a compression spring or an extension spring, and the installation positions of the two are just opposite. In this embodiment, the spring 7 is an extension spring.

Further, as shown in fig. 2 and 6, the pin clamping device further includes a fixed bar 81 disposed on the mounting plate 11, a movable bar 82 cooperating with the fixed bar 81 to clamp the pin 5, a first driving rod 83 and a second driving rod 84 for driving the movable bar 82 to move away from or close to the fixed bar 81, and a connecting rod 85 connecting the first driving rod 83 and the second driving rod 84; the first driving rod 83 and the second driving rod 84 are rotatably disposed on the mounting plate 11, and the second driving rod 84 is rotatably connected to the other end of the driving cylinder 42. Two pins 5 for fixing the PCB are arranged, and one pin 5 is fixed through the inclined wedge block 3 and the clamping groove 2; another pin 5 is fixed through fixed strip 81 and activity strip 82, can fix two pins 5 through a drive actuating cylinder promptly, effectual improvement work efficiency, reduction in production cost.

Table 1 pin clamping device compares existing pneumatic clamping device

As can be seen from table 1:

(1) after the experimental conditions are strictly controlled, the improved pin clamping device has better zero return performance than an original gas clamp in a force contrast test experiment, the improved pin clamping device is about 10 microns, and the original gas clamp is about 18-20 microns.

(2) After the improved pin clamping device is loaded with forward and backward inertia forces, the rotation quantity of the dial indicator and the return zero value are in a uniform and symmetrical distribution state, so that the processing error is homogenized, and the processing precision is improved. Therefore, the pin clamping device has essential improvement on the control of the pin posture, and the practical effect of the invention is verified.

It is to be understood that the invention is not limited to the examples described above, but that modifications and variations may be effected thereto by those of ordinary skill in the art in light of the foregoing description, and that all such modifications and variations are intended to be within the scope of the invention as defined by the appended claims.

Claims

1. A pin clamping device for clamping a pin in a vertical position for positioning a PCB board, comprising: the clamping device comprises a clamping seat assembly and an inclined wedge block, wherein the clamping seat assembly is provided with a clamping groove, the inclined wedge block is arranged on the clamping groove in a sliding mode and is provided with a clamping surface, a limiting part capable of abutting against the side surface of a pin is arranged at the clamping end of the clamping groove, the inclined wedge block is pressed to the clamping end under the action of external force, and the clamping surface is pressed towards the pin to the limiting part to clamp the pin; the sliding direction of the inclined wedge block is vertical to the moving direction of the PCB, the clamping surface and the moving direction of the inclined wedge block are arranged in a beta degree, wherein beta is more than or equal to 30 degrees and less than or equal to 60 degrees; the clamping surface is a curved surface with a convex middle part.

2. The pin clamping device of claim 1, wherein: the pin clamping device further comprises a power assembly used for driving the wedge block to slide on the clamping groove, the wedge block is pressed to the clamping end under the driving of the power assembly, and the clamping surface is pressed towards the pin to the limiting portion so as to clamp the pin.

3. A pin holding device as claimed in claim 1, wherein one end of the wedge is further provided with a notch for receiving dust and machining debris, the notch being provided on the underside of the holding surface.

4. The pin clamp of claim 1, wherein the β is 45 °.

5. A pin holding arrangement as claimed in claim 1, in which the limit stop is a right angle end face.

6. The pin clamping device according to claim 2, wherein the power assembly comprises a wedge fork rotatably arranged on the clamping seat assembly and used for driving the wedge block to move, and a driving cylinder rotatably connected with one end of the wedge fork; the other end of the wedge shifting fork is movably connected with the wedge block through a limiting shaft and a waist-shaped hole, one of the waist-shaped hole and the limiting shaft is arranged on the wedge shifting fork, and the other end of the waist-shaped hole and the limiting shaft is arranged on the wedge block; when the limiting part is matched with the wedge block to clamp the pin, the normal line of the arc contact of the inner wall of the waist-shaped hole and the limiting shaft and the motion direction of the wedge block form an alpha degree, wherein alpha is more than 0 degree and less than 15 degrees.

7. The pin clamping device of claim 6, wherein the clamping base assembly includes a mounting plate, a guide cover plate disposed on the mounting plate, and a securing block disposed at one end of the guide cover plate; the clamping groove comprises a guide groove and a limiting groove arranged at one end of the guide groove; the limiting groove is formed in the fixing block, the guide groove is formed in the guide cover plate, and the limiting portion is arranged on the limiting groove.

8. A pin holding arrangement as claimed in claim 6, wherein said α is 10 °.

9. A pin holding arrangement as claimed in claim 7, further comprising a spring for providing a clamping force, the spring being secured at one end to the mounting plate and at the other end to the wedge yoke.

10. The pin clamping device according to claim 9, further comprising a fixed bar disposed on the mounting plate, a movable bar cooperating with the fixed bar to clamp the pin, a first driving bar and a second driving bar for driving the movable bar away from or toward the fixed bar, and a connecting rod connecting the first driving bar and the second driving bar; the first driving rod and the second driving rod are rotatably arranged on the mounting plate, and the second driving rod is rotatably connected with the other end of the driving cylinder.