CN106514370A

CN106514370A - Clamp

Info

Publication number: CN106514370A
Application number: CN201610951262.5A
Authority: CN
Inventors: 罗传鹏; 杨洪春
Original assignee: Guangdong Evenwin Precision Technology Co Ltd
Current assignee: Guangdong Evenwin Precision Technology Co Ltd
Priority date: 2016-10-26
Filing date: 2016-10-26
Publication date: 2017-03-22

Abstract

The invention discloses a clamp which comprises a base, a positioning plate, a positioning boss, a pressing device and a driving device, wherein the base comprises a base part and a supporting table arranged on the base part; the positioning plate is arranged on the supporting platform, is provided with a vertical guide sliding hole and is provided with a supporting surface; the positioning boss is inserted into the sliding guide hole and can vertically move along the sliding guide hole, and the upper part of the positioning boss is used for inserting a cavity of a workpiece; the pressing device is used for pressing the workpiece on the supporting surface; the driving device is used for driving the positioning boss to ascend and descend along the guide sliding hole so as to enable the positioning boss to ascend to the top surface of the cavity for supporting the workpiece. The positioning boss is kept not to contact with the top surface of the cavity of the workpiece, and the workpiece is tightly pressed on the supporting surface to be pre-clamped. Then, the driving device drives the positioning boss to ascend to be in contact with the top surface of the cavity of the workpiece, so that the workpiece can be prevented from being pulled and deformed; meanwhile, the top surface of the cavity of the workpiece can be supported.

Description

A kind of fixture

Technical field

The present invention relates to the fixture of digit control machine Tool processing technique field, particularly Digit Control Machine Tool.

Background technology

In Digit Control Machine Tool（CNC）Upper processing electronic product（Such as mobile phone, panel computer, electronic reader etc.）Shell it Before, Set and Positioning need to be carried out to workpiece to be processed by fixture, it is clear that can fixture be to affect workpiece by clamping workpiece in place The key factor of crudy.

Existing numerical control machine tool clamp is as shown in figure 1, which includes location-plate 100 and can be loaded on numerically controlled machine （It is not shown）On pedestal 200, the top of pedestal 200 be provided with the edge of the top surface of 201 support platform of support platform have many to On the limited post 202 that stretches out, the position relative with limited post 202 of location-plate 100 is provided with the first spacing hole 101, location-plate 202 Located at support platform 200 top surface and its first spacing hole 101 is placed on limited post 202, can prevent location-plate 100 occur level turn It is dynamic or mobile.Have the positioning boss 102 for raising up in the middle part of the top surface of location-plate 100, the shape of positioning boss 102 according to The shape of the cavity 301 of workpiece and set, and be formed in one with location-plate 100.The structure of workpiece 300 as shown in Figure 2 and Figure 3, Which includes housing 300, and housing 300 defines the cavity 301 of bottom opening, the bottom of four side side walls of housing 300 have level to The sole 302 for overhanging.After housing 300 is placed on positioning boss 102, the top surface of its cavity 301 is supported by positioning boss 102, pin Plate 302 is contacted with the supporting surface 103 located at 100 top surface of location-plate and at least two soles 302 are provided with and can be inserted in limited post 202 The second spacing hole 303, with prevent workpiece level movement or rotate.Meanwhile, the position of 200 surrounding of pedestal is provided with lever cylinder 400, lever cylinder 400 can press sole 302 in supporting surface 103, to prevent the vertical movement of workpiece, so as to realize the dress of workpiece Folder.

But existing fixture, due to the structure that its positioning boss 102 is formed in one with location-plate 100, and after assembling Remain stationary as.In such a case it is necessary to the step dimension for making fixture vertical（That is 102 top surface of positioning boss and supporting surface 103 Vertical distance）And the vertical dimensional accuracy of the cavity 301 of workpiece is when being in the minimum margin of tolerance, workpiece is just can guarantee that Clamping precision.Although and in fact, the vertical step dimension precision of fixture can reach tolerance（For example can reach +/- 0.01MM）.After but the vertical size of the cavity 301 of corresponding workpiece is because of error present in forming process or shaping The factor such as deformation affect, can there is larger tolerance, often the following two kinds cannot typically occurs not with step precise match Good situation：1st, when the vertical step dimension of fixture is significantly greater than the vertical size of the cavity of workpiece, hanging sole 302 is in thick stick Under the pressure effect of bar cylinder 400, the surrounding of workpiece can be pulled to deform downwards（I.e. workpiece deforms in N-shaped）.2nd, when fixture is vertical The step dimension cavity that is significantly less than workpiece vertical size when, the cavity top surface of workpiece cannot get positioning boss 102 and support. During processing, under the pressure effect of cutter, the workpiece roof at the top of positioning boss 102 occurs lower notch distortion（It is in u-shaped Deformation）, and this all will affect the crudy of workpiece.

The content of the invention

The main object of the present invention is to propose a kind of fixture, it is intended to ensure the accurate clamping of workpiece, it is to avoid workpiece deforms.

For achieving the above object, the present invention proposes a kind of fixture, including：

Pedestal, the pedestal include base portion and the supporting table on the base portion；

Location-plate, in the supporting table, the location-plate opens up vertical slide guide hole to the location-plate, and the location-plate has Supporting surface；

Positioning boss, the positioning boss are plugged in the slide guide hole and can be along the vertical movement of the slide guide hole, the convex The top of platform is used for the cavity for inserting workpiece；

Hold down gag, the hold down gag for by the Work-sheet pressing in the supporting surface；

Driving means, the driving means are lifted along the slide guide hole for ordering about the positioning boss, so that the convex Platform rises to the top surface of the cavity for supporting the workpiece.

Location-plate and positioning boss are designed as two independent individualities by technical solution of the present invention, in the level of location-plate Portion region opens up slide guide hole, so that the bottom of positioning boss is inserted and vertical can be slided.Meanwhile, it is fixed to drive to arrange driving means Position boss is along the vertical movement of slide guide hole.Before clamping workpiece, driving means are first made to drive positioning boss in relatively low position, Workpiece is then inserted in the top of positioning boss, and passes through hold down gag by workpiece（It is preferred that the sole of workpiece）Press in support Face, completes the Primary Location of workpiece；Then, positioning boss rising is ordered about by driving means；When positioning boss rises to and work When the top surface of the cavity of part contacts, driving means stop driving positioning boss lifting（Will positioning boss be locked in the position Put）, complete the clamping work of workpiece.After completion of processing, the downward reset movement of positioning boss is ordered about by driving means, and released After hold down gag is to the compression of workpiece, workpiece is removed, complete the processing of workpiece.The present invention during clamping workpiece, with First it is held in position boss not contact with the cavity top surface of workpiece, and the sole of workpiece is pressed on supporting surface, carries out pre- clamping. Then leading to driving means again drives positioning boss to rise to the mode contacted with the cavity top surface of workpiece, ensure that workpiece not Can compacted device drawing deformation；Can guarantee that the top surface of the cavity of workpiece obtains the support of positioning boss simultaneously, so as to work in-process, Be not in that workpiece roof is extruded to sagging situation generation by cutter, and then ensure the accurate clamping of workpiece, it is to avoid workpiece deforms.

Preferably, the driving means include the first cylinder, and the piston rod of first cylinder is directly or by middleware Contact with the bottom surface of the positioning boss, and support the positioning boss, when the piston rod of first cylinder is flexible, drive institute State positioning boss lifting, when the positioning boss rises to the top surface of the cavity for supporting the workpiece, first cylinder Piston rod stops stretching out, and the positioning boss is locked.

Preferably, first cylinder including one or more, first cylinder is located at the base portion, and is located at The lower section of the positioning boss, the supporting table are provided with the via passed through for the piston rod or middleware of first cylinder.

Preferably, the driving means include the first screw mandrel and the support member being rotatably connected on first screw mandrel, described One screw mandrel is located at base portion, and positioned at the lower section of the positioning boss, the top of the support member is contacted with the positioning boss, and The positioning boss is supported, the support member is twisted and can be ordered about the positioning boss lifting, the positioning boss rises to and institute During the top surface contact of the cavity for stating workpiece, the clamping to workpiece is completed.

Preferably, the location-plate offers multiple the first vertical spacing holes, and the supporting table is spacing with described first The relative position in hole is provided with the first limited post for being inserted upwardly into first spacing hole, fixed so that level is carried out to the location-plate Position.

Preferably, it is its sole that the workpiece is pressed in the position on the supporting surface by the hold down gag, at least Two first spacing holes are arranged on the position relative with the sole of the workpiece, and the sole of the workpiece is opened up and described The second relative spacing hole of one spacing hole, the top of first limited post insert described second through after first spacing hole Spacing hole, to carry out horizontal location to the workpiece.

Preferably, the supporting table includes support base and gripper shoe, and the support base includes two sides being oppositely arranged Plate, the both sides of the gripper shoe are connected in two side plates.

Preferably, it is its sole that the workpiece is pressed in the position on the supporting surface by the hold down gag, described tight Pressure device includes the second cylinder on the base portion and the paw located at the piston rod end of second cylinder, described Second cylinder is used to drive the paw that the sole of the workpiece is pressed in the supporting surface.

Preferably, second cylinder includes multiple, and its cylinder body is located at the base portion relative with the sole of the workpiece, The cylinder body or the base portion of second cylinder is provided with free bearing, and described paw one end is articulated with the piston of second cylinder Boom end, is articulated with the free bearing in the middle part of the paw, the other end of the paw is free end, the work of second cylinder When stopper rod stretches, the relatively described free bearing of the paw can be driven to swing, and can be by the Work-sheet pressing on the supporting surface.

Preferably, the hold down gag is pressed in the position on the supporting surface for its sole, and the hold down gag includes Multiple second screw mandrels, the paw for being placed on second screw mandrel and the casting die being rotatably connected on second screw mandrel, twist the casting die Order about that the paw is descending, and make one end of the paw that the sole of the workpiece is pressed on the locating surface.

Description of the drawings

Fig. 1 is the schematic perspective view of existing fixture；

Fig. 2 is the schematic perspective view of workpiece；

Fig. 3 is the schematic perspective view of another angle of workpiece；

Fig. 4 is the schematic perspective view of the present invention；

Fig. 5 is the sectional view after clamping workpiece of the present invention；

Fig. 6 is the enlarged detail of the part A of Fig. 4；

Fig. 7 is the enlarged detail of the part B of Fig. 5.

Specific embodiment

Below in conjunction with the accompanying drawing in the embodiment of the present invention, the technical scheme in the embodiment of the present invention is carried out clear, complete Site preparation is described, it is clear that described embodiment a part of embodiment only of the invention, rather than the embodiment of whole.Base Embodiment in the present invention, those of ordinary skill in the art obtained under the premise of creative work is not made it is all its His embodiment, belongs to the scope of protection of the invention.

If it is to be appreciated that directionality instruction is related in the embodiment of the present invention（Such as up, down, left, right, before and after ...）, Then directionality indicates to be only used for explaining in a certain particular pose（As shown in drawings）Under relative position relation between each part, Motion conditions etc., if the particular pose changes, directionality indicates also correspondingly to change therewith.

The present invention proposes a kind of fixture.

In embodiments of the present invention, as shown in Figures 2 to 7, the fixture includes pedestal 1, location-plate 2, positioning boss 3, pressure Tight device 4 and driving means 5.

The pedestal 1 includes base portion 11 and the supporting table on base portion 12, and the pedestal 1 is placed in the work of Digit Control Machine Tool Part platform（It is not shown）Afterwards, its base portion 11 is by worktable support；In the supporting table 12, the location-plate 2 is opened up location-plate 2 Vertical slide guide hole 21, the location-plate 2 have supporting surface 22, in the level of the location-plate 2 that the slide guide hole 21 is preferably opened in Portion region；The positioning boss 3 is plugged in the slide guide hole 21 and can be along 21 vertical movement of the slide guide hole, the hole of slide guide hole 21 Wall can be formed to the spacing of positioning boss 3 with the sidewall contact of positioning boss 3, and the top of the positioning boss 3 is used to insert work The cavity of part 300, the shape of the cavity 301 of its workpiece 300 described in shape Main Basiss and set, workpiece is electronic product（Such as Mobile phone, panel computer, electronic reader etc.）Shell；The hold down gag 4 is located at pedestal 1, is preferably disposed to the base portion of pedestal 1 11 surrounding, hold down gag for the workpiece 300302 is pressed in supporting surface 22, to prevent workpiece 300 from moving, specifically Ground, hold down gag can be pressed in the sole 302 of workpiece on supporting surface 22；The driving means 5 are used to order about 3 edge of positioning boss Slide guide hole 21 is lifted, so that positioning boss 3 can rise to the top surface of the cavity 301 for supporting workpiece 300.

Before clamping workpiece 300, driving means 5 are first made to drive positioning boss 3 in relatively low position, then by workpiece 300 tops for being inserted in positioning boss 3, and pressed the sole 302 of workpiece 300 in the supporting surface 22 by hold down gag 4, it is complete Into the Primary Location of workpiece 300；Then, order about positioning boss 3 by driving means 5 to rise；When positioning boss 3 rises to and work When the top surface of the cavity 301 of part 300 contacts, driving means 5 stop driving positioning boss lifting（Will positioning boss 3 lock In the position）, complete the clamping work of workpiece 300.After completion of processing, positioning boss 3 is ordered about by driving means 5 and resetted downwards It is mobile, and after releasing compression of the hold down gag 4 to workpiece 300, workpiece 300 is removed, complete the processing of workpiece 300.The present invention During clamping workpiece 300, do not contacted with the top surface of the cavity 301 of workpiece 300 with being first held in position boss 3, and by work The sole 302 of part 300 presses on supporting surface 22, carries out pre- clamping.Then leading to driving means 5 again drives positioning boss 3 to rise To the mode contacted with the top surface of the cavity 301 of workpiece 300.Ensure that workpiece 300 will not the drawing deformation of compacted device 4； Can guarantee that the top surface of the cavity 301 of workpiece 300 obtains the support of positioning boss 3 simultaneously, so as to work in-process, be not in workpiece 300 roofs are extruded to sagging situation by cutter to be occurred.And then ensureing 300 accurate clamping of workpiece, it is to avoid workpiece 300 deforms.

In an embodiment of the present invention, as shown in figure 5, the driving means 5 include the first cylinder 51, first cylinder 51 piston rod is directly or by middleware（Such as push pedal, it is not shown）Contact with the bottom surface of positioning boss 3, and support convex Platform 3, when the piston rod of first cylinder 51 is flexible, drives the positioning boss 3 to lift, when positioning boss 3 rises to support During the top surface of the cavity 301 of workpiece 300, piston rod stops stretching out, and positioning boss 3 is locked in the position；And work as piston rod During contraction, positioning boss 3 declines with which, and waits the clamping of next subjob to work.

Specifically, as shown in figure 5, the number of first cylinder 51 is one or more, using the situation of, can With cost-effective；But in view of the smoothness of the movement of positioning boss 3, and the stability of clamping, the first cylinder 51 can be adopted It is multiple（Fig. 5 show the situation of two）Which is located on the base portion 11 of pedestal 1, and positioned at the lower section of the positioning boss 3, it is described Supporting table 12 is provided with the via 121 passed through for the piston rod or middleware of the first cylinder 51, so that piston rod or middleware Positioning boss 3 can be supported.

It should be noted that rising to the cavity with workpiece 300 with regard to whether the first cylinder 51 accurately orders about positioning boss 3 301 top surface contacts.Can be detected by an unaided eye by field personnel and be judged, when judging in place, workpiece personnel then control First cylinder 51 so as to which piston rod stops lifting, positive stop lug boss 3 is locked in and is contacted with the top surface of the cavity 301 of workpiece 300 Position.But artificial judgment the mode for controlling, are present uncertain after all.For this purpose, can be by arranging pressure detecting dress Put（It is not shown）To realize, such as in the gases at high pressure delivery pipe for leading to the first cylinder 51（It is not shown）Upper setting pressure detecting dress Put, when first cylinder 51 drive the positioning boss 3 rise to contact with the top surface of the cavity 301 of workpiece 300 after, The piston rod of one cylinder 51 to resistance will necessarily change, and now, the air pressure in gases at high pressure delivery pipe also can be with With change, when the air pressure in pressure-detecting device detects gases at high pressure delivery pipe changes（Or change to a fixed number During value）, the pressure signal provided according to pressure-detecting device by outside control system, the piston rod for controlling the first cylinder 51 stop Only stretch, positive stop lug boss 3 is locked in the position contacted with the top surface of the cavity 301 of workpiece 300.Except above-mentioned mode it Outward, shoring can be adopted with following manner, i.e. the first cylinder 51, during the piston rod of shoring stretches out, is such as run into Resistance when reaching certain value, the spring in the cylinder body of shoring can be compressed（It is not shown）, when resistance reaches preset value and by bullet During spring compression scheduled volume, shoring self-locking, its piston rod stop stretching, so as to positive stop lug boss 3 is accurately locked in and workpiece 300 Cavity 301 the position that contacts of top surface.It should be noted that shoring is prior art and is those skilled in the art It is known, no longer its structure and operation principle are repeated here, wherein, compress the spring into and promote the pre- of shoring self-locking Handicapping force value much smaller than the power that workpiece 300 is supportted deformation, to ensure that positioning boss is accurately positioned.

In addition to the above described embodiments, driving means 5 can also adopt other embodiment.For example, the driving means 5 Including the first screw mandrel（It is not shown）, and the support member that is rotatably connected on first screw mandrel（It is not shown）, first screw mandrel is located at The base portion 11 of pedestal 1, and positioned at the lower section of positioning boss 3, the top of the support member is contacted with positioning boss 3, and supports institute State positioning boss 3.Twist support member and can order about positioning boss 3 and lift, positioning boss 3 rises to and the cavity 301 of workpiece 300 When top surface is contacted, the clamping to workpiece 300 is completed.Specifically, the number of first screw mandrel can include one or more, The number of the support member is corresponding to the first screw mandrel, and each described support member is rotatably connected on corresponding first screw mandrel.This embodiment Simple structure, material and processing cost it is relatively low.It should be noted that those skilled in the art are being understood illustrated by above-described embodiment Structure outside, it is also conceivable to other driving device structures or be equal to the structure of above-mentioned driving means and all should be limited in this Within the protection domain of invention.

In one embodiment, as shown in Figures 2 to 5, the compacting device 4 includes the second cylinder 41 on base portion 11 And located at the paw 42 of the piston rod end of the second cylinder 41, the second cylinder 41 is used to drive the paw 42 by workpiece 300 Sole 302 be pressed on the supporting surface 22, to prevent 300 horizontal movement of workpiece.Specifically, second cylinder 41 includes It is multiple, base portion 11 with the sole 302 of the workpiece 300 relative, the cylinder body of second cylinder 41 of its cylinder body located at pedestal 1 Or base portion is provided with free bearing 43,42 one end of the paw is articulated with the end of the piston rod of second cylinder 41, the pressure The middle part of pawl 42 is articulated with the free bearing 43, and the other end of the paw 42 is free end, and the piston rod of the second cylinder 41 stretches When, 42 relative free bearing 43 of paw can be driven to swing, when the paw 42 is rocked to the sole of its described other end and workpiece 300 When 302 top offsets, the sole 302 of the workpiece 300 can be pressed on supporting surface 22, so as to prevent workpiece 300 from moving.

In addition to the above described embodiments, hold down gag 4 can also adopt other embodiment.For example, the hold down gag 4 Including the second screw mandrel（It is not shown）, be placed on second screw mandrel（It is not shown）Paw 42, and be rotatably connected on second screw mandrel Casting die（It is not shown）, casting die is used to drive paw to press the sole 302 of the workpiece 300.Second screw mandrel include it is multiple, Which is located at the base portion 11 of pedestal 1 and relative with the sole 302 of the workpiece 300.Twisting casting die, can to order about the paw 42 descending Offseted with the top by one end of the paw 42 with the sole 302 of workpiece 300, so as to the sole 302 of workpiece 300 is pressed in On the locating surface 22, this embodiment simple structure, material and processing cost it is relatively low.It should be noted that art technology Personnel understand above-described embodiment illustrated by structure outside, it is also conceivable to other hold down gag structures or be equal to above-mentioned The structure of hold down gag all should be limited within protection scope of the present invention.

In embodiments of the present invention, as shown in Fig. 2, Fig. 3, Fig. 4, Fig. 6, the location-plate 2 offers multiple vertical by One spacing hole 23, the position relative with first spacing hole 23 of the supporting table 12 are provided with and are inserted upwardly into the first spacing hole 23 First limited post 122, to carry out horizontal location to location-plate 2, on the one hand, when can prevent from processing workpiece 300, location-plate 2 is because of pressure Not enough there is horizontal movement greatly in the thrust of tight device 4, on the other hand, is easy to location-plate 2 is installed in supporting table 12.

Further, at least two the first spacing holes 23 are arranged on the position relative with the sole 302 of workpiece 300, institute The sole 302 for stating workpiece 300 opens up second spacing hole 303 relative with the first spacing hole 23, first limited post 122 it is upper Portion inserts the second spacing hole 303 through after the first spacing hole 23, to carry out horizontal location to workpiece 300.On the one hand, can prevent from adding During work workpiece 300, there is horizontal movement because the thrust of hold down gag 4 is not big enough in workpiece, on the other hand, is easy in location-plate Workpiece 300 is installed on 2.It should be noted that being not necessarily to open up the first limit in the position of the sole 302 of correspondence workpiece 300 Position hole 23, and workpiece 100 can be corresponded in location-plate 2 when the first spacing hole 23 is not relative with the sole 302 of workpiece 300 Second limited post 24 of the second spacing hole 303 that can be inserted into sole 302 is set on the position of sole 302.

In the embodiment of the present invention, as shown in Figure 4, Figure 5, the shape of the supporting table 12 and numerous embodiments are configured with, Which can be overall structure, or Split type structure.Supporting table 12 can be detachably connected by welding or by various Structure is connected with base portion 11, for example the Detachable connection structure such as buckle, screw or lock.Certainly, supporting table 12 can also be with Base portion 11 is integrally formed, and integrally formed shaping structures are convenient, Stability Analysis of Structures.

In one embodiment, send out shown in Fig. 4, supporting table 12 includes support base 123 and the gripper shoe on support base 124.Specifically, the support base 123 includes two side plates 1231,1232 being oppositely arranged, and the both sides of the gripper shoe 124 connect In described two side plates 1231,1232, this setup simple structure, material and processing cost it is relatively low.Specifically, described Fagging 124 with side plate 1231,1232 can be connected by welding or by various Detachable connection structures, for example, buckle, spiral shell The Detachable connection structure such as nail or lock.Certainly, gripper shoe 124 can also with two side plates 1231,1232 one into Type.In view of the stability of structure, the support base 123 can be arranged to square frame-like structure（It is not shown）, gripper shoe sets 124 In frame like structure.It should be noted that in the embodiment of the present invention, the support base 123 is except being square frame-like structure Outside, can also be triangle or other shapes, every those skilled in the art according to it is described above it is contemplated that other Clamping support is regarded as the deformation of the embodiment of the present invention or substitute mode.

The preferred embodiments of the present invention are these are only, the scope of the claims of the present invention is not thereby limited, it is every in the present invention Inventive concept under, the equivalent structure transformation made using description of the invention and accompanying drawing content, or directly/be used in indirectly which The technical field of his correlation is included in the scope of patent protection of the present invention.

Claims

1. A clamp, characterized in that, comprising:

a base, the base includes a base and a support platform arranged on the base;

A positioning plate, the positioning plate is arranged on the support platform, the positioning plate is provided with a vertical guide hole, and the positioning plate has a supporting surface;

A positioning boss, the positioning boss is inserted into the guide slide hole and can move vertically along the guide slide hole, and the upper part of the positioning boss is used to insert into the cavity of the workpiece;

a pressing device, the pressing device is used to press the workpiece onto the supporting surface;

A driving device, the driving device is used to drive the positioning boss up and down along the guide slide hole, so that the positioning boss rises to the top surface of the cavity supporting the workpiece.

2. The fixture according to claim 1, wherein the driving device comprises a first air cylinder, and the piston rod of the first air cylinder contacts the bottom surface of the positioning boss directly or through an intermediate piece, and supports the The positioning boss, when the piston rod of the first cylinder stretches, drives the positioning boss up and down, when the positioning boss rises to the top surface of the cavity supporting the workpiece, the first cylinder’s The piston rod stops stretching out, and the positioning boss is locked.

3. The clamp according to claim 2, characterized in that: the first cylinder includes one or more, the first cylinder is arranged on the base, and is located below the positioning boss, the support The platform is provided with a through hole through which the piston rod or intermediate piece of the first cylinder passes.

4. The fixture according to claim 1, wherein the driving device comprises a first screw rod and a support member screwed on the first screw rod, the first screw rod is arranged at the base, And located below the positioning boss, the top of the support is in contact with the positioning boss, and supports the positioning boss, turning the support can drive the positioning boss up and down, the positioning When the boss rises to contact with the top surface of the cavity of the workpiece, the clamping of the workpiece is completed.

5. The fixture according to claim 1, characterized in that: the positioning plate is provided with a plurality of vertical first limiting holes, and the position of the supporting table opposite to the first limiting holes is provided with an upward The first limiting column inserted into the first limiting hole is used to horizontally position the positioning plate.

6. The fixture according to claim 5, characterized in that: the part of the workpiece pressed against the supporting surface by the pressing device is its foot plate, and at least two of the first limiting holes are provided At the position opposite to the foot plate of the workpiece, a second limit hole opposite to the first limit hole is opened on the foot plate of the workpiece, and the upper part of the first limit post passes through the first limit hole. The hole is inserted into the second limiting hole to horizontally position the workpiece.

7. The fixture according to claim 7, wherein the support table includes a support seat and a support plate, the support seat includes two opposite side plates, and the two sides of the support plate are connected to two the side panels.

8. The fixture according to any one of claims 1 to 7, characterized in that: the part of the workpiece pressed against the supporting surface by the pressing device is its foot plate, and the pressing device includes The second air cylinder arranged on the base and the pressing claw arranged at the end of the piston rod of the second air cylinder, the second air cylinder is used to drive the pressing claw to press the foot plate of the workpiece against the supporting surface.

9. The clamp as claimed in claim 8, characterized in that: the second air cylinder comprises a plurality, the cylinder body of which is arranged at the base and is opposite to the foot plate of the workpiece, the cylinder body of the second air cylinder or The base is provided with a hinge seat, one end of the pressure claw is hinged to the end of the piston rod of the second cylinder, the middle part of the pressure claw is hinged to the hinge seat, and the other end of the pressure claw is a free end , when the piston rod of the second air cylinder expands and contracts, the pressing claw is driven to swing relative to the hinge seat, and can press the workpiece tightly on the supporting surface.

10. The fixture according to any one of claims 1 to 7, characterized in that: the part of the workpiece pressed against the supporting surface by the pressing device is its foot plate, and the pressing device includes A plurality of second screw rods, pressure claws sleeved on the second screw rods, and a pressure piece screwed on the second screw rods, twisting the pressure piece drives the pressure claws down, and makes the pressure pieces One end of the pressing claw presses the foot plate of the workpiece against the positioning surface.