CN110153747B

CN110153747B - Machining clamp

Info

Publication number: CN110153747B
Application number: CN201910468050.5A
Authority: CN
Inventors: 李荣辉; 梁梅新; 向春华; 王梓
Original assignee: Guangdong Evenwin Precision Technology Co Ltd
Current assignee: Guangdong Evenwin Precision Technology Co Ltd
Priority date: 2019-05-31
Filing date: 2019-05-31
Publication date: 2020-10-23
Anticipated expiration: 2039-05-31
Also published as: CN110153747A

Abstract

The invention relates to a machining clamp which is used for clamping a workpiece, wherein the workpiece comprises a shell and an inner cavity arranged on the shell, the inner wall of the inner cavity is in an irregular shape, the machining clamp comprises a base, a supporting table, a supporting nozzle and a driving assembly, and the supporting table is arranged on the base; the supporting nozzle is arranged on the supporting table and comprises a fixing piece and at least two supporting blocks arranged on the fixing piece, a through hole is formed between the two supporting blocks, the driving component can be inserted into the through hole to drive the at least two supporting blocks to be opened so as to be abutted against the inner wall of the inner cavity of the workpiece, and the supporting blocks are used for being attached to the surface of the inner wall of the inner cavity of the workpiece and corresponding to the inner wall of the inner cavity to form profiling positioning. By adopting the profiling positioning mode, the workpiece can be prevented from rotating relative to the supporting nozzle, the supporting force of the supporting nozzle on the inner wall of the inner cavity is more uniform, and the supporting stability is improved.

Description

Machining clamp

Technical Field

The invention relates to the technical field of machining, in particular to a machining clamp.

Background

When the electronic product housing is machined, the electronic product housing is usually clamped and positioned by a clamp, so that the electronic product housing is more conveniently machined.

Most present watch shell adopts integral type center structure, and watch shell can set up the side opening usually, and traditional processing mode is through the fixture clamping in the gauge outfit position of watchcase, then processes the side opening on the watchcase. However, the appearance of the watch case is easily damaged by the clamping mode, and the clamping is unstable, so that the watch case is easy to shake during processing.

Disclosure of Invention

In view of the above, there is a need to provide a machining fixture with more stable and firm positioning.

The utility model provides a add clamping apparatus for the clamping work piece, the work piece includes the casing and sets up inner chamber on the casing, the inner wall of inner chamber is irregular shape, add clamping apparatus includes:

a base;

the supporting table is arranged on the base;

prop and drive assembly, prop and chew and locate on the brace table, prop and chew including the mounting with locate two at least supporting shoes on the mounting, two form the through-hole between the supporting shoe, drive assembly can insert the through-hole opens in order to support in order to drive two at least the supporting shoe in order to hold on the inner wall of the inner chamber of work piece, the supporting shoe be used for laminating in the face of the inner wall of the inner chamber of work piece with the inner wall of inner chamber is corresponding in order to form the profile modeling location.

By adopting the technical scheme, the workpiece can be prevented from rotating relative to the supporting nozzle so as to improve the matching firmness of the workpiece and the supporting nozzle, and the surface of the supporting block, which is attached to the inner wall of the inner cavity of the workpiece, is larger due to the adoption of a profiling positioning mode, so that the supporting force of the supporting nozzle on the inner wall of the inner cavity is more uniform, and the supporting stability is improved;

the supporting nozzle is supported in the inner cavity of the workpiece in a profiling positioning mode, and the inner wall of the inner cavity is irregular in shape, so that the outer side wall of the supporting nozzle, which is used for supporting the inner wall of the inner cavity, is also irregular in shape corresponding to the inner wall of the inner cavity, the clamping position of the workpiece can not deviate by adopting the clamping mode, the workpiece can be clamped more stably, and the workpiece is not easy to fall off; furthermore, the inner wall of the inner cavity has no appearance surface and is high in requirement, so that damage to the appearance surface caused by clamping on the appearance surface can be reduced.

In one embodiment, the supporting block is provided with a clearance groove, and when the supporting block is supported in the inner cavity of the workpiece, the position of the supporting block corresponds to the position of the side hole on the workpiece, so that a tool for machining the side hole can enter the clearance groove after penetrating through the shell of the workpiece.

By adopting the technical scheme, when the supporting block is supported in the inner cavity of the workpiece, the position of the avoiding groove corresponds to the position of the side hole on the workpiece actually, and then when the side hole is machined, for example, when the side hole is machined through a cutter, the cutter can further enter the avoiding groove after penetrating through the shell of the workpiece, so that the supporting block is prevented from being directly damaged after the cutter penetrates through the shell of the workpiece.

In one embodiment, the supporting block is provided with a positioning step which can be clamped on the surface of the workpiece to axially position the workpiece.

By adopting the technical scheme, when the supporting block is inserted into the inner cavity of the workpiece, the bottom of the workpiece can be just clamped on the positioning step, so that the workpiece is positioned in the axial direction through the positioning step, and the workpiece can be stably positioned and supported.

In one embodiment, the supporting block is elastically connected to the fixing member; or the supporting block is hinged to the fixing piece.

By adopting the technical scheme, after the convex block of the pull rod is moved out of the through hole, the supporting block can return to the folded state by elasticity, so that the use is more convenient and flexible.

In one embodiment, the driving assembly includes a pull rod and a driving source connected to the pull rod to drive the pull rod to move in the through hole, the pull rod includes a rod body and a protrusion protruding outward from the rod body, and when the protrusion enters the through hole, the protrusion can be supported on the supporting blocks to move the supporting blocks away from each other.

By adopting the technical scheme, when the lug enters the through hole, the lug can be supported on the supporting blocks through the lug which protrudes outwards and is arranged on the pull rod, so that the supporting blocks are far away from each other, the workpiece can be firmly supported, and the firmness of positioning the workpiece is improved.

In one embodiment, the surface of the projection for supporting the support block is an inclined surface.

By adopting the technical scheme, the convex block can gradually prop open the supporting blocks through the inclined plane, and the movement process is more stable.

In one embodiment, the device further comprises a stroke adjusting assembly, wherein the stroke adjusting assembly comprises a limiting block, a first limiting block and a second limiting block, the limiting block is arranged between the first limiting block and the second limiting block, and the distance between the first limiting block and the second limiting block is adjustable;

the driving source is sequentially connected with the limiting block and the pull rod to drive the limiting block to move between the first limiting part and the second limiting part, and the limiting block can respectively impact on the first limiting part and the second limiting part.

By adopting the technical scheme, the movement stroke of the limiting block can be adjusted, and the limiting block is fixedly connected with the pull rod and moves synchronously, so that the movement stroke of the pull rod can be adjusted through the stroke adjusting assembly, and then the opening distances of a plurality of opening nozzles driven by the pull rod are adjusted to adapt to different workpieces, and the universality is improved.

In one embodiment, each of the first limiting member and the second limiting member includes a threaded end and a supporting end, the first limiting member is threaded to the supporting platform through the threaded end, and the second limiting member is threaded to the base through the threaded end.

By adopting the technical scheme, the structure is simple and the adjustment is convenient.

In one embodiment, the driving assembly comprises a pull rod and a handle connected with the pull rod to drive the pull rod to lift, and the pull rod is connected with the supporting platform or the base in a threaded mode.

By adopting the technical scheme, the manual adjustment can be more flexible, and unstable factors in automatic adjustment are reduced.

In one embodiment, the supporting table is provided with a positioning guide block, and two ends of the positioning guide block are supported on two lugs on the workpiece.

By adopting the technical scheme, the positioning guide block is supported between the two gauge outfits to prevent the workpiece from rotating and improve the positioning reliability.

In summary, the following steps: the surface of the supporting block, which is attached to the inner side wall of the inner cavity of the workpiece, corresponds to the inner wall of the inner cavity to form profiling positioning, so that the workpiece can be prevented from rotating relative to the supporting nozzle, the matching firmness of the workpiece and the supporting nozzle is improved, and the surface of the supporting block, which is attached to the inner wall of the inner cavity of the workpiece, is larger due to the adoption of the profiling positioning mode, so that the supporting force of the supporting nozzle on the inner wall of the inner cavity is more uniform, and the supporting stability is improved;

Drawings

FIG. 1 is a schematic diagram of a machining fixture in one embodiment of the present application;

FIG. 2 is a cross-sectional view of the machining fixture shown in FIG. 1;

FIG. 3 is a schematic view of the structure of a holder in an embodiment of the present application, and FIG. 3 also shows a part of the structure of a driving assembly and the structure of a workpiece;

FIG. 4 is a transverse cross-sectional view of the support block of FIG. 3 for support within the inner cavity portion;

FIG. 5 is an axial cross-sectional view of the machining fixture in the embodiment of FIG. 2;

fig. 6 is a schematic structural view of a machining jig in another embodiment of the present application.

Reference numerals: 10. a workpiece; 11. a housing; 12. a surface ear; 13. a side hole; 14. an inner cavity; 100. a base; 200. a support table; 300. a mouth is opened; 310. a fixing member; 320. a support block; 321. a groove; 322. a protrusion; 330. a through hole; 340. a position avoiding groove; 350. positioning a step; 400. a drive assembly; 410. a pull rod; 411. a rod body; 412. a bump; 413. a threaded connection; 420. a drive source; 430. a stroke adjustment assembly; 431. a limiting block; 432. a first limit piece; 4321. a rod portion; 4322. a threaded segment; 433. a second limiting member; 4331. a support portion; 4332. a threaded portion; 440. a handle; 500. and positioning the guide block.

Detailed Description

To facilitate an understanding of the invention, the invention is described more fully below with reference to the accompanying drawings. Preferred embodiments of the present invention are shown in the drawings. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

It will be understood that when an element is referred to as being "secured to" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. In contrast, when an element is referred to as being "directly on" another element, there are no intervening elements present. The terms "vertical," "horizontal," "left," "right," and the like as used herein are for illustrative purposes only.

Fig. 1 is a schematic structural view of a machining jig used for clamping and positioning a workpiece 10 according to an embodiment. For example, referring to fig. 3, the workpiece 10 may be a case of a wristwatch, the case of the wristwatch includes a case 11 and four lugs 12 disposed on the case 11, the case 11 is provided with four lugs 12, two of the lugs 12 are a group, that is, one end of a band may be mounted between two lugs 12, and the other end of the band may be mounted between the other two lugs 12. The watch body is provided with an inner cavity 14, the shape of the inner cavity 14 is irregular, specifically, the inner wall of the inner cavity 14 is not a complete cylindrical surface, and the inner wall of the inner cavity 14 is provided with a bulge or a recess. The housing 11 is provided with a side hole 13, and the side hole 13 penetrates the housing 11 and communicates the inner cavity 14 with the outside of the housing 11. The machining fixture penetrates through the inner cavity 14 of the workpiece 10 in a profiling positioning mode, then supports and clamps the inner cavity 14 of the workpiece 10, and then machines the side hole 13 on the workpiece 10.

Fig. 2 is a sectional view of the machining jig shown in fig. 1, and as shown in fig. 1 and 2, the machining jig includes a base 100, a supporting table 200, a mouth 300 and a driving assembly 400, wherein the supporting table 200 is disposed on the base 100, the mouth 300 is disposed on the supporting table 200, and the driving assembly 400 is used for driving the mouth 300 to open so that the mouth 300 can be supported in the inner cavity 14 of the workpiece 10.

Fig. 3 is a schematic view of the structure of a holder 300 in one embodiment, and fig. 3 also shows a partial structure of a driving assembly 400 and a structure of a workpiece 10. As shown in fig. 3, the holder 300 includes a fixing member 310 and at least two supporting blocks 320, the supporting blocks 320 are disposed on the fixing member 310, a through hole 330 is formed between the two supporting blocks 320, and the through hole 330 extends downward and through the fixing member 310. The driving assembly 400 includes a pull rod 410, the pull rod 410 includes a rod body 411 and a protrusion 412 disposed on the rod body 411, the pull rod 410 passes through the through hole 330, when the protrusion 412 enters the through hole 330, the protrusion 412 can be supported on the supporting blocks 320, so that the at least two supporting blocks 320 are separated and opened, and the supporting blocks 320 can be supported on the inner wall of the inner cavity 14 of the workpiece 10, so as to fix the workpiece 10.

In one embodiment, the supporting block 320 can be attached to the inner wall of the workpiece 10, and the surface of the supporting block 320 for attaching to the inner wall of the inner cavity 14 has a shape corresponding to the attached position of the inner wall of the inner cavity 14, that is, the supporting block 320 and the inner wall of the inner cavity 14 are located in a contour shape. Since the inner wall of the inner cavity 14 has an irregular shape, for example, it may have both protrusions and depressions, and correspondingly, as shown in fig. 4, fig. 4 is a transverse cross-sectional view of the portion of the supporting block 320 for supporting in the inner cavity 14 in fig. 3, the supporting block 320 is also provided with a groove 321 for accommodating the protrusions on the inner wall, or the supporting block 320 is also provided with a protrusion 322 inserted into the depression on the inner wall. By adopting the matching mode, the workpiece 10 can be prevented from rotating relative to the mouth 300 so as to improve the matching firmness of the workpiece 10 and the mouth 300, and due to the adoption of the profiling positioning mode, the surface of the supporting block 320, which is attached to the inner wall of the inner cavity 14 of the workpiece 10, is larger, the supporting force of the mouth 300 on the inner wall of the inner cavity 14 is more uniform, and the supporting stability is improved.

In one embodiment, as shown in fig. 3, four supporting blocks 320 may be provided, and the four supporting blocks 320 are substantially quarter cylinders, i.e. the four supporting blocks 320 may substantially surround a cylindrical structure, and the through holes 330 are formed between the four supporting blocks 320. In other embodiments, the support blocks 320 may be arranged, for example, three or five, etc. The supporting mouth 300 is supported in the inner cavity 14 of the workpiece 10 in a profiling positioning mode, and the inner wall of the inner cavity 14 is irregular in shape, so that the outer side wall of the supporting mouth 300, which is used for supporting the inner wall of the inner cavity 14, is also irregular in shape corresponding to the inner wall of the inner cavity 14, the clamping position of the workpiece 10 can not be deviated by adopting the clamping mode, the clamping of the workpiece 10 can be more stable, and the workpiece 10 is not easy to fall off; further, since the inner wall of the inner cavity 14 has no appearance surface, the requirement is high, and damage to the appearance surface caused by clamping on the appearance surface can be reduced.

In one embodiment, as shown in fig. 3, the pull rod 410 includes a rod 411 and a protrusion 412, the rod 411 may be cylindrical, the protrusion 412 is disposed at one end of the rod 411, and the protrusion 412 is formed by protruding an outer wall of the rod 411, when the rod 411 is inserted into the through hole 330, the rod 411 does not prop the supporting blocks 320 apart from each other, and after the rod 411 drives the protrusion 412 to enter the through hole 330, the protrusion 412 props the supporting blocks 320, so as to prop the supporting blocks 320 apart. For example, the face of the protrusion 412 for supporting the supporting block 320 is an inclined face; for another example, the protrusion 412 is in a truncated cone shape, the side surface of the protrusion 412 is a tapered surface, and a tapered surface is correspondingly provided at the port portion of the through hole 330, since the through hole 330 is surrounded by the plurality of supporting blocks 320, the tapered surface at the port portion of the through hole 330 is actually provided at the end portion of the supporting block 320.

In one embodiment, as shown in fig. 3, the supporting block 320 is provided with a clearance groove 340, when the supporting block 320 is supported in the inner cavity 14 of the workpiece 10, the position of the clearance groove 340 actually corresponds to the position of the side hole 13 on the workpiece 10, so that when the side hole 13 is machined, for example, when the side hole 13 is machined by a tool, the tool can further enter the clearance groove 340 after penetrating through the housing 11 of the workpiece 10, thereby preventing the tool from directly damaging the supporting block 320 after penetrating through the housing 11 of the workpiece 10.

In one embodiment, as shown in fig. 3, the supporting block 320 is further provided with a positioning step 350, the positioning step 350 is arranged on an outer side wall of the supporting block 320 and is approximately located in the middle of the supporting block 320, when the supporting block 320 is inserted into the inner cavity 14 of the workpiece 10, the bottom of the workpiece 10 can be just clamped on the positioning step 350, so that the workpiece 10 can be positioned and supported stably by the positioning step 350 in the axial direction. For example, the positioning step 350 may include a continuous plane, that is, the positioning step 350 on each supporting block 320 includes a complete and continuous plane, and the complete plane can be completely supported on the workpiece 10 to provide stable support for the workpiece 10. For another example, the step on each supporting block 320 includes a plurality of small positioning blocks arranged at intervals, and the small positioning blocks can be exactly supported on the workpiece 10, so that when the surface of the workpiece 10 is not a plane, the heights of the small positioning blocks can be correspondingly set, so that each small positioning block can be supported on the workpiece 10, thereby improving the stability of supporting the workpiece 10. For example, a spatial rectangular coordinate system may be established, the axial direction is the Z-axis direction, the X-axis, the Y-axis and the Z-axis are perpendicular to each other, the supporting block 320 is outwardly opened and supported in the inner cavity 14 of the workpiece 10, so as to position the workpiece 10 in the X-axis direction and the Y-axis direction, the positioning step 350 is supported on the workpiece 10, so as to position the workpiece 10 in the Z-axis direction, and further, the positioning and clamping firmness of the workpiece 10 is better.

In one embodiment, as shown in fig. 3, the supporting block 320 may be fixedly connected to the fixing member 310, the supporting block 320 may have a certain elasticity, or the supporting block 320 may be elastically connected to the fixing member 310, and when the protrusion 412 of the pull rod 410 moves upward out of the through hole 330, the supporting block 320 may be elastically restored to the closed state. In one embodiment, the support block 320 may be made of two parts, a hard material for supporting the inner cavity 14 of the workpiece 10 and an elastic material for connecting to the fixing member 310. In one embodiment, the supporting block 320 may also be directly hinged to the fixing member 310, and an elastic member may be installed between the fixing member 310 and the supporting block 320, so that the supporting block 320 may be elastically restored to the closed state after the protrusion 412 of the pull rod 410 is moved upward out of the through hole 330; there may be no elastic member between the supporting blocks 320 and the fixing member 310, and the supporting blocks 320 may be folded by hand when the nozzle 300 is mounted in the cavity 14 of the workpiece 10.

In one embodiment, as shown in fig. 2, the pull rod 410 of the drive assembly 400 moves up and down to drive the plurality of gathered struts 300 to open for support within the internal cavity 14 of the workpiece 10. The driving assembly 400 can control the lifting of the pull rod 410 by automatic driving, and the driving assembly 400 can also control the lifting of the pull rod 410 by manual driving.

As shown in fig. 2, fig. 2 provides an automatic driving manner, and the driving assembly 400 includes a driving source 420, an output end of the driving source 420 can move in a linear direction, and an output end of the driving source 420 is connected to the pull rod 410. In the embodiment shown in fig. 2, the driving source 420 is a cylinder. Further, the driving assembly 400 further includes a stroke adjusting assembly 430, fig. 5 is an axial cross-sectional view of the machining fixture in the embodiment shown in fig. 2, the stroke adjusting assembly 430 includes a limiting block 431, a first limiting member 432 and a second limiting member 433, the limiting block 431 is disposed between the first limiting member 432 and the second limiting member 433, one end of the limiting block 431 is connected to the driving assembly 400, and the other end of the limiting block 431 is connected to the pull rod 410, and the driving assembly 400 can drive the limiting block 431 and the pull rod 410 to perform a synchronous lifting motion. Specifically, when the stopper 431 moves upward and hits the first stopper 432, the end point position of the stopper 431 moving upward is limited by the first stopper 432, and when the stopper 431 moves downward and is clamped to the second stopper 433, the end point position of the stopper 431 moving downward is limited by the second stopper 433, that is, the first stopper 432 and the second stopper 433 are spaced apart from each other, and the stopper 431 can move between the first stopper 432 and the second stopper 433. Further, the distance between the first limiting member 432 and the second limiting member 433 can be adjusted, so that the movement stroke of the limiting member 431 can be adjusted, and the limiting member 431 and the pull rod 410 are fixedly connected and move synchronously, so that the movement stroke of the pull rod 410 can be adjusted through the stroke adjusting assembly 430, and further the distance that the plurality of nozzles 300 driven by the pull rod 410 are opened is adjusted, so as to adapt to different workpieces 10.

In one embodiment, as shown in fig. 5, the first limiting member 432 is a threaded member, the first limiting member 432 includes a rod portion 4321, a threaded section 4322 is disposed at an upper end of the rod portion 4321, the threaded section 4322 is threadedly connected to the supporting platform 200, a lower end of the rod portion 4321 extends downward from the supporting platform 200, and a length of the lower end of the rod portion 4321 extending out of the supporting platform 200 can be adjusted by rotating the first limiting member 432. As shown in fig. 5, the second limiting member 433 includes a supporting portion 4331 and a threaded portion 4332, the threaded portion 4332 is screwed to the base 100, and the length of the supporting portion 4331 extending out of the base 100 can be adjusted by rotating the threaded portion 4332.

Fig. 6 is a schematic structural diagram of a machining fixture in an embodiment, in which the pull rod 410 is controlled to be lifted and lowered by a manual driving manner. Specifically, the bottom of the pull rod 410 is provided with a threaded connection 413, the pull rod 410 is in threaded connection with the base 100 through the threaded connection 413, the pull rod 410 is provided with a handle 440, and the pull rod 410 can be driven to rotate by horizontally pulling the handle 440, so that the pull rod 410 can be lifted through the threaded connection 413. In other embodiments, the screw 413 of the pull rod 410 may be screwed to the support 200, and the pull rod 410 may be rotated by pulling the handle 440, so that the pull rod 410 is lifted up and down by the screw 413.

In one embodiment, as shown in fig. 1, the supporting platform 200 is provided with two positioning guide blocks 500, the two positioning guide blocks 500 are respectively disposed between the two lugs 12, and two ends of the positioning guide blocks 500 are supported on the two lugs 12. The positioning guide block 500 is supported between the two lugs 12 to prevent the workpiece 10 from rotating, thereby improving the reliability of positioning. For example, the positioning guide block 500 may be made of an elastic material such as an acrylic material or rubber to prevent damage to the surface of the workpiece 10.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims

1. The utility model provides a machining clamp which characterized in that for the clamping work piece, the work piece includes the casing and sets up inner chamber on the casing, the inner wall of inner chamber is irregular shape, machining clamp includes:

a base;

the supporting table is arranged on the base;

the supporting nozzle is arranged on the supporting table and comprises a fixing piece and at least two supporting blocks arranged on the fixing piece, a through hole is formed between the two supporting blocks, the driving assembly can be inserted into the through hole to drive the at least two supporting blocks to be opened to be abutted against the inner wall of the inner cavity of the workpiece, and the supporting blocks are used for being attached to the surface of the inner wall of the inner cavity of the workpiece and corresponding to the inner wall of the inner cavity to form profiling positioning;

the driving assembly comprises a pull rod and a driving source which is connected with the pull rod to drive the pull rod to move in the through hole;

the stroke adjusting device comprises a first limiting part, a second limiting part and a stroke adjusting assembly, wherein the stroke adjusting assembly comprises a limiting block, the first limiting part and the second limiting part, the limiting block is arranged between the first limiting part and the second limiting part, and the distance between the first limiting part and the second limiting part is adjustable; the driving source is sequentially connected with the limiting block and the pull rod to drive the limiting block to move between the first limiting part and the second limiting part, and the limiting block can respectively impact on the first limiting part and the second limiting part.

2. The machining fixture according to claim 1, wherein the support block is provided with a clearance groove, and when the support block is supported in the inner cavity of the workpiece, the position of the support block corresponds to the position of the side hole in the workpiece, so that a tool for machining the side hole can enter the clearance groove after penetrating through the housing of the workpiece.

3. The machining jig of claim 1, wherein the support block is provided with a positioning step capable of being held on the surface of the workpiece to axially position the workpiece.

4. The machining jig of claim 1, wherein the support block is elastically connected to the fixing member; or the supporting block is hinged to the fixing piece.

5. The machining jig of claim 1, wherein the draw bar includes a bar body and an outwardly projecting projection provided on the bar body, the projection being capable of supporting on the support blocks when the projection enters the through hole to move the plurality of support blocks away from each other.

6. The machining jig of claim 5, wherein the face of the projection for supporting the support block is an inclined face.

7. The machining fixture according to claim 6, wherein the first retaining member and the second retaining member are both threaded members.

8. The machining jig of claim 7, wherein the first limiting member and the second limiting member each include a threaded end and a support end, the first limiting member is threadedly connected to the support base through the threaded end, and the second limiting member is threadedly connected to the base through the threaded end.

9. The machining fixture according to claim 1, wherein the driving assembly comprises a pull rod and a handle connected to the pull rod to drive the pull rod to ascend and descend, and the pull rod is connected to the support table or the base in a threaded manner.

10. The machining jig according to claim 1, wherein the support base is provided with a positioning guide block, and both ends of the positioning guide block are supported by two lugs on the workpiece.