CN116550857A

CN116550857A - Punching machine for metal pipe fittings

Info

Publication number: CN116550857A
Application number: CN202310844072.3A
Authority: CN
Inventors: 陈潇; 宋高峰; 吴胜平
Original assignee: Special Equipment Safety Supervision Inspection Institute of Jiangsu Province
Current assignee: Special Equipment Safety Supervision Inspection Institute of Jiangsu Province
Priority date: 2023-07-11
Filing date: 2023-07-11
Publication date: 2023-08-08
Anticipated expiration: 2043-07-11
Also published as: CN116550857B

Abstract

The invention relates to the technical field of metal pipe fitting machining, and particularly discloses a metal pipe fitting punching machine, wherein a machine frame is provided with a workbench, a limiting component is arranged on the workbench and is suitable for limiting square pipes, a first linear driving device is arranged on the workbench, a punch is arranged at the output end of the first linear driving device, a push rod is arranged at the output end of the second linear driving device, a guide plate is arranged on the push rod, the guide plate is provided with an inclined guide groove, the limiting plate is in limiting sliding connection with the push rod, the limiting plate is provided with a slidable pressing column, the pressing column is provided with a guide rod which slides to penetrate through the guide groove, the pressing column is provided with a groove, the limiting component is provided with a limiting block, the push rod is in a first moving state, the push rod drives the limiting plate to move downwards, the punch is penetrated into a punched hole in a second moving state, the limiting plate is propped against the limiting block, and the punch is matched with the groove. The metal pipe fitting punching machine provided by the invention realizes the synchronization of burr removal and punch return, saves time and labor, and improves the working efficiency in burr removal.

Description

Punching machine for metal pipe fittings

Technical Field

The invention relates to the technical field of metal pipe fitting machining, in particular to a metal pipe fitting punching machine.

Background

In the case of square pipes, it is often necessary to perform punching processing. The surface of the square tube after punching forms burrs, and the burrs are usually positioned in the inner cavity of the square tube and are not easy to remove. To solve this problem, chinese patent publication No. CN210676572U discloses a hydraulic square tube punching apparatus, which includes a guide tube, a punching rod, a punching block and a lower pressing plate, the guide tube is adapted to be sleeved with a square tube to be processed, the punching rod and the guide tube are consistent in length direction and slidingly fit in the guide tube, a punching opening is provided on a peripheral wall of the guide tube, and the punching block is slidingly fit in the punching opening and provided with an inclined surface corresponding to the punching rod. When the square tube punching device is used, the lower pressing plate presses down the punching surface of the square tube to be processed under the action of the lower pressing cylinder, the punching rod extrudes the inclined plane under the action of the punching cylinder, and therefore the punching block slides in the punching opening and punches out the punched hole in the peripheral wall of the square tube to be processed. The punching mode is to punch from the inner side to the outer side of the square tube to be processed, and the punched burrs formed by the punching mode protrude out of the outer surface of the square tube. The burrs on the outer surface of the square tube are beneficial to subsequent polishing and processing, and are easy to clean.

However, the inventors found that there are the following technical problems when implementing the hydraulic square tube punching apparatus: this fluid pressure type side pipe punching equipment has promoted the convenient degree of burr removal, however, can not directly remove the burr. In the subsequent process, the worker also needs to polish burrs on the outer surface of the square tube, thereby consuming time and labor. In addition, the deburring is carried out in a polishing mode, so that the time is long, and the working efficiency is reduced.

Disclosure of Invention

The invention provides a metal pipe punching machine, which aims to solve the problems that in the related art, the process of deburring is needed to be additionally arranged, time and labor are wasted, and the working efficiency is low in deburring.

The metal pipe fitting punching machine comprises a frame, a limiting assembly, a first linear driving device, a second linear driving device and a limiting plate, wherein the frame is provided with a workbench; the limiting assembly is arranged on the workbench and is suitable for limiting the square tube; the first linear driving device is arranged on the workbench, and the output end of the first linear driving device is provided with a punch which faces the square tube and is suitable for punching the square tube; the second linear driving device is arranged above the workbench, a push rod extending along the height direction of the rack is arranged at the output end of the second linear driving device, a guide plate is arranged on the peripheral surface of the push rod, and an inclined guide groove is formed in the guide plate; limiting plate with the push rod is followed the spacing sliding connection of direction of height of frame, the limiting plate is equipped with slidable press post, press post with the slip direction of drift is unanimous, press post is equipped with to slide and wears to locate guide bar in the guide way, press post deviate from the terminal surface of push rod is equipped with the recess, spacing subassembly have with the limiting plate corresponds from top to bottom and is located the inboard stopper of side pipe, the push rod has first mobile state and second mobile state first mobile state, the push rod drives press post with the limiting plate moves down the second mobile state the drift is in punch a hole of punching a hole of locating on the perisporium of side pipe, the limiting plate only support in the stopper, the push rod promotes press post orientation the drift slides, the drift cooperate in the recess.

Preferably, the limiting assembly comprises four clamping blocks and a punching die, wherein the four clamping blocks are distributed in a rectangular shape, two adjacent clamping blocks are mutually symmetrical, the clamping blocks are arranged above the workbench, the cross section of each clamping block is L-shaped, and a limiting space is formed in the corner area of each clamping block; the punching die is of a square tubular structure and extends along the height direction of the frame, the punching die is arranged above the workbench, four corners of the punching die are respectively arranged in the limiting spaces of the four clamping blocks, the square tube is suitable for being sleeved on the outer peripheral surface of the punching die and is limited between the clamping blocks and the punching die, a yielding gap is formed between every two adjacent clamping blocks, a positioning hole communicated with the yielding gap is formed in the peripheral wall of the punching die, and when the push rod is in the second moving state, the punch is slidably inserted into the positioning hole, and the positioning hole is coaxial with the pressing column.

Preferably, the number of the positioning holes is equal to and corresponds to the number of the abdication gaps, the positioning holes are communicated with the corresponding abdication gaps, the number of the first linear driving devices is equal to and corresponds to the number of the positioning holes one by one, and the positioning holes are used for the punches of the corresponding first linear driving devices to pass through; the guide plates are four and are distributed at intervals in the circumferential direction of the push rod, the guide plates are in one-to-one correspondence with the punches, the guide plates extend along the sliding directions of the corresponding punches, the number of the pressing columns is equal to that of the guide plates and in one-to-one correspondence with the guide plates, the guide rods of the pressing columns are arranged in the guide grooves of the corresponding guide plates in a sliding manner, and the sliding directions of the pressing columns and the corresponding punches are consistent; when the push rod is in the second moving state, the push rod pushes the pressing column to slide towards the corresponding punch, and the punch is matched in the groove of the corresponding pressing column.

Preferably, the punching die comprises a body and a plate group, wherein the body is arranged above the workbench, the peripheral wall of the body is provided with placement grooves corresponding to the four abdication gaps one by one, the body is provided with an inner cavity, and when the square pipe is separated from the punching die, the placement grooves are communicated with the inner cavity and the corresponding abdication gaps; the plate group with the quantity of mounting groove equals and the one-to-one, the plate group includes along the direction of height of frame slidable ground sets up in corresponding first baffle and second baffle in the mounting groove, first baffle with the second baffle is in the direction of height of frame is last relatively, the second baffle with be connected with first spring between the body, first baffle is equipped with first arc hole, the second baffle be equipped with the second arc hole of first arc hole intercommunication, first arc hole with the second arc hole constitutes the locating hole, the diameter of clamp column is greater than the aperture of locating hole, first arc hole with the second arc hole all be equipped with be used for with the chamfer that the clamp column counterpointed.

Preferably, the punching die further comprises clamping frames which are equal to the plate groups in number and correspond to each other one by one, the clamping frames are elastically connected with the body, the clamping frames are provided with two clamping rods which are symmetrical to each other in the height direction of the frame, the plate groups are clamped between the two clamping rods of the corresponding clamping frames, the free ends of the clamping rods are provided with inclined planes which face the inner sides of the corresponding plate groups, the clamping frames are provided with wedge-shaped blocks located in the inner cavities of the body, the wedge-shaped blocks are located above the limiting blocks and adjacent to the limiting blocks, the limiting plates are matched with the inner periphery of the body, and in the second moving state of the push rod, the limiting plates are abutted against the limiting blocks and force the wedge-shaped blocks to move towards the outer sides of the body, and the clamping rods are separated from the plate groups.

Preferably, the first baffle and the second baffle in the plate group are elastically connected.

Preferably, a containing area is formed between every two adjacent compression columns, the limiting plates are provided with ventilation pipelines which are equal to the containing area in number and correspond to each other one by one, the ventilation pipelines are arranged in the corresponding containing areas, two pipe orifices are respectively close to the two adjacent compression columns, the output end of the second linear driving device is provided with an annular pipe which extends along the circumferential direction of the push rod, a plurality of flexible pipes are communicated between each of the ventilation pipelines and the annular pipe, and the metal pipe punching machine further comprises an air pump which is arranged at the output end of the second linear driving device and is communicated with the annular pipe.

Preferably, the output end of the first linear driving device is elastically and slidably connected with a pressing block located between the square tube and the punch, the pressing block is provided with a through hole matched with the punch and used for the punch to pass through, and the pressing block is suitable for pressing the peripheral wall of the square tube when the punch punches.

Preferably, the metal pipe fitting punching machine further comprises a material guiding pipe, the workbench is provided with a through hole communicated with the inner cavity of the body, a first end of the material guiding pipe is communicated with the inner cavity of the body through the through hole, and a second end of the material guiding pipe is suitable for discharging the blanking of the square pipe.

Preferably, the part of the mounting groove below the second baffle forms a sliding groove, the first springs are multiple and are all located in the sliding groove, the punching die further comprises cover plates which are equal to the sliding grooves in number and correspond to the sliding grooves one by one, the cover plates are located in the inner cavity of the body and close the corresponding sliding grooves, and the cover plates are connected with the body.

Compared with the related art, the invention has the following beneficial effects:

1. when the punch returns, the groove of the pressing column is matched with the punch and synchronously moves in the same direction, and the part of the pressing column for forming the groove is pressed against the edge of the hole of the square tube, so that the extrusion and removal of burrs at the edge of the hole of the square tube are realized. Therefore, the deburring and the return of the punch are synchronously carried out, and the process of additionally adding the deburring is avoided, so that the time is saved. In addition, the press column removes burrs under the action of the second linear driving device, so that the labor intensity of workers is reduced, and the labor is saved. In addition, compare in the mode of polishing the burr, the burr at press post direct extrusion hole edge can realize the quick removal of burr, has reduced the time of burring, has promoted work efficiency.

2. The diameter of the pressing column is larger than the aperture of the positioning hole, so that the thickness of the convex ring of the pressing column is increased, the structural strength of the convex ring is enhanced, the deformation degree of the convex ring is smaller after long-term use, the replacement frequency of the convex ring is reduced, and the service lives of the pressing column and the convex ring are prolonged.

3. When the pressing column presses the first baffle and the second baffle outwards, the air pump sucks the scraps at the gap between the first baffle and the second baffle through the pipe orifice of the ventilation pipe, and the scraps are prevented from falling into the gap area between the first baffle and the second baffle, so that the first baffle and the second baffle can be tightly closed when reset, and the reliability of the positioning hole is guaranteed.

Drawings

Fig. 1 is a schematic perspective view of a metal pipe punching machine according to embodiment 1 of the present invention.

Fig. 2 is a schematic perspective view of a portion from a first linear driving device to a second linear driving device in embodiment 1 of the present invention.

Fig. 3 is an enlarged schematic view of a of fig. 2 in embodiment 1 of the present invention.

Fig. 4 is a schematic perspective view showing a first linear driving device to a punching die portion in embodiment 1 of the present invention.

Fig. 5 is a schematic perspective view of a limiting plate portion in embodiment 1 of the present invention.

Fig. 6 is a schematic perspective view of a press stud portion in embodiment 1 of the present invention.

Fig. 7 is a schematic perspective view of a limiting component part in embodiment 1 of the present invention.

Fig. 8 is a schematic perspective view of the pusher block to briquette portion in example 1 of the present invention.

Fig. 9 is a schematic perspective view of a limiting assembly according to embodiment 2 of the present invention.

Fig. 10 is a schematic perspective view of a clamping frame to plate pack portion in embodiment 2 of the present invention.

Fig. 11 is a schematic cross-sectional view of the first baffle plate to the second baffle plate portion in embodiment 2 of the present invention.

Fig. 12 is a perspective view of a body portion in embodiment 2 of the present invention.

Fig. 13 is a perspective view of a frame and a guide pipe portion in embodiment 2 of the present invention.

Fig. 14 is a schematic perspective view of a second linear driving device to a supporting frame part in embodiment 3 of the present invention.

Fig. 15 is an enlarged schematic view of B of fig. 14 in embodiment 3 of the present invention.

Reference numerals: 1. a frame; 11. a work table; 111. a through hole; 112. a support frame; 1121. a support post;

2. a limit component; 21. square tubes; 22. a limiting block; 23. clamping blocks; 24. punching a hole die; 241. positioning holes; 242. a body; 2421. a placement groove; 24211. a sliding groove; 2422. a chute; 2423. a first slip groove; 2424. a second slip groove; 2425. an inner cavity; 243. a plate group; 2431. a first baffle; 24311. a first arcuate aperture; 24312. a first slide bar; 24313. a slip hole; 2432. a second baffle; 24321. a second arcuate aperture; 24322. a second slide bar; 24323. a sliding rod; 2433. a third spring; 244. a first spring; 245. a closure plate; 2451. blocking; 246. a clamping frame; 2461. a clamping rod; 24611. an inclined plane; 2462. wedge blocks; 247. a second spring; 248. a cover plate; 25. a relief void; 26. a bottom plate;

3. A first linear driving device; 31. a punch; 32. briquetting; 321. a via hole; 322. a slide bar; 34. a pushing block;

4. a second linear driving device; 41. a push rod; 411. a limit flange; 42. a guide plate; 421. a guide groove; 43. a limiting plate; 431. a slide hole; 432. a bar-shaped groove; 433. a sleeve; 4331. an opening; 434. a ventilation duct; 44. pressing a column; 441. a guide rod; 442. a groove; 443. a relief groove; 444. a convex ring; 45. an annular tube; 46. a hose;

5. a material guiding pipe;

6. a sliding table; 61. a sliding cylinder.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings. The embodiments described below by referring to the drawings are illustrative and intended to explain the present invention and should not be construed as limiting the invention.

A metal tube punching machine according to an embodiment of the present invention is described below with reference to fig. 1 to 15.

As shown in fig. 1 to 8, in embodiment 1, the metal pipe punching machine of the present invention comprises a frame 1, a limiting assembly 2, a first linear driving device 3, a second linear driving device 4 and a limiting plate 43, wherein the frame 1 is provided with a workbench 11. The spacing assembly 2 is mounted to the table 11 and is adapted to define a square tube 21. The first linear drive device 3 is provided on the table 11, and a punch 31 adapted to punch the square tube 21 is provided at an output end thereof. The second linear driving device 4 is disposed above the table 11, and the output end is provided with a push rod 41 extending along the height direction of the frame 1, the peripheral surface of the push rod 41 is provided with a guide plate 42, and the guide plate 42 is provided with an inclined guide groove 421. Limiting plate 43 and push rod 41 follow the spacing sliding connection of the direction of height of frame 1, limiting plate 43 is equipped with slidable pressure post 44, the slip direction of pressure post 44 and drift 31 is unanimous, pressure post 44 is equipped with the guide bar 441 that slides and wear to locate in the guide slot 421, the terminal surface that pressure post 44 deviates from push rod 41 is equipped with recess 442, spacing subassembly 2 has and corresponds from top to bottom and lie in the stopper 22 of side pipe 21 inboard with limiting plate 43, push rod 41 has first mobile state and second mobile state, in the first mobile state, push rod 41 drives pressure post 44 and limiting plate 43 downwardly move, in the second mobile state, drift 31 punches a hole on the perisporium of side pipe 21 and wears to locate in the punching hole, limiting plate 43 ends in stopper 22, push rod 41 promotes pressure post 44 to slide towards drift 31, drift 31 cooperates in recess 442.

In use, the first linear drive device 3 drives the punch 31 to move toward the square tube 21 and to punch a hole in the peripheral wall of the square tube 21. Meanwhile, the second linear driving device 4 drives the push rod 41 to move downwards along the height direction of the frame 1, the push rod 41 drives the guide plate 42, the limiting plate 43 and the pressing column 44 to move downwards synchronously, when the limiting plate 43 is stopped against the limiting block 22, the limiting plate 43 stops moving downwards, the push rod 41 and the guide plate 42 continue to move downwards, the guide plate 42 drives the pressing column 44 to slide towards the punch 31 through the cooperation of the guide groove 421 and the guide rod 441, and the groove 442 is close to the punch 31 and cooperates with the punch 31. Then, under the cooperative operation of the first linear driving device 3 and the second linear driving device 4, the punch 31 gradually returns, and the recess 442 of the plunger 44 and the punch 31 synchronously move in the same direction, whereby the engaged state of the recess 442 and the punch 31 is always maintained. When the punch 31 gradually withdraws from the punched hole, the groove 442 gradually approaches the inner peripheral surface of the square tube 21 and is aligned with the hole of the square tube 21. Subsequently, the portion of the pressing post 44 for constituting the groove 442 is pressed against the edge of the hole of the square tube 21, whereby the portion of the pressing post 44 for constituting the groove 442 presses the burr of the hole edge of the square tube 21, the removal of the burr is achieved, and the burr is prevented from remaining inside the square tube 21. Meanwhile, the punch 31 is still in the hole of the square tube 21, so that burrs are prevented from extending into the hole of the square tube 21 when being extruded by the part of the pressing column 44 for forming the groove 442, the removing strength and the removing effect of the burrs are ensured, and the hole forming effect of the punch 31 on the peripheral wall of the square tube 21 is ensured.

After the burrs at the hole edges of the square tube 21 are removed, the punch 31 continues to return, the groove 442 and the punch 31 are separated, and the pressing column 44 is returned under the action of the second linear driving device 4.

In the above embodiment, the punch 31 can remove burrs simultaneously during the return. Therefore, the procedure of additionally arranging the deburring is avoided, and the time is saved. In addition, the pressing column 44 removes burrs under the action of the second linear driving device 4, so that the labor intensity of workers is reduced, and the labor is saved. In addition, compared with the mode of polishing burrs, the burrs at the edges of the hole can be removed rapidly by directly extruding the burrs by the pressing column 44, the deburring time is reduced, and the working efficiency is improved.

Wherein the table 11 is horizontally arranged.

The square tube 21 is provided in the height direction of the frame 1, the punch 31 is movable in the horizontal direction, and the punch 31 faces the square tube 21.

It will be appreciated that the direction of movement of the push rod 41 coincides with the height direction of the frame 1.

Wherein, both ends of the guiding groove 421 are closed, the first end of the guiding rod 441 is adjacent to the push rod 41, and the second end of the guiding groove 421 is located above the first end and far away from the push rod 41.

The limiting plate 43 is horizontally arranged, the plane shape of the limiting plate 43 is square, the size of the limiting plate is smaller than the inner peripheral size of the square tube 21, and the limiting plate 43 and the square tube 21 are vertically opposite.

Wherein, the center of the limiting plate 43 is provided with a sliding hole 431 coaxial with the push rod 41, the limiting plate 43 is slidably sleeved on the outer circumferential surface of the push rod 41 through the sliding hole 431, the limiting plate 43 is provided with a bar-shaped groove 432 for the guide plate 42 to slide through, the bottom end of the push rod 41 is provided with a limiting flange 411 propped against the lower end of the limiting plate 43, and the limiting flange 411 prevents the limiting plate 43 from sliding out from the bottom end of the push rod 41.

Wherein, limiting plate 43 is equipped with along the sleeve 433 of the radial extension of push rod 41, and pressure post 44 sliding fit is in sleeve 433, and the perisporium of sleeve 433 is equipped with the opening 4331 that is used for supplying deflector 42 to slide through.

The pressing post 44 is provided with a relief groove 443 penetrating up and down, the guide rod 441 is located in the relief groove 443, two ends of the guide rod 441 are fixedly connected with the pressing post 44, and the relief groove 443 is used for the guide plate 42 to slide through.

It will be appreciated that both the recess 442 and the punch 31 are cylindrical and that the cross-sectional dimensions of the recess 442 and the punch 31 are substantially equal.

As can be appreciated, the diameter of the hole punched by the punch 31 on the peripheral wall of the square tube 21 is equal to the diameter of the punch 31.

For ease of understanding, arrow N in fig. 1 shows the height direction of the frame 1.

Specifically, the limiting assembly 2 comprises clamping blocks 23 and a punching die 24, the clamping blocks 23 are four and are distributed in a rectangular shape, two adjacent clamping blocks 23 are mutually symmetrical, the clamping blocks 23 are arranged above the workbench 11, the cross section of each clamping block is L-shaped, and a limiting space is formed in the corner area of each clamping block 23. The punching die 24 is of a square tubular structure and extends along the height direction of the frame 1, the punching die 24 is arranged above the workbench 11, four corners of the punching die are respectively arranged in limit spaces of the four clamping blocks 23, the square tube 21 is suitable for being sleeved on the outer peripheral surface of the punching die 24 and is limited between the clamping blocks 23 and the punching die 24, a yielding gap 25 is formed between two adjacent clamping blocks 23, a positioning hole 241 communicated with the yielding gap 25 is formed in the peripheral wall of the punching die 24, and when the push rod 41 is in a second moving state, the punch 31 is slidably inserted into the positioning hole 241, and the positioning hole 241 and the compression column 44 are coaxial.

The punching die 24 and the clamping blocks 23 limit the position of the square tube 21, and stability and reliability of the square tube 21 in the punching process are guaranteed. The positioning holes 241 are used to position holes to be punched in the square pipe 21. In punching, the punch 31 moves toward the positioning hole 241 and presses the square tube 21. When the punching is completed, the punch 31 is inserted into the positioning hole 241 by the impact force, whereby the positioning hole 241 also achieves the relief for the punch 31.

It will be appreciated that the locating hole 241 is coaxial with the punch 31.

As can be appreciated, the punch 31 punches a hole having a smaller diameter than the positioning hole 241 in the peripheral wall of the square tube 21.

When the punch 31 returns, the groove 442 of the pressing column 44 and the punch 31 cooperate and synchronously move in the same direction, the pressing column 44 is pressed against the edge of the hole of the square tube 21 through the positioning hole 241.

It should be noted that, the limiting assembly 2 further includes a bottom plate 26, the bottom plate 26 is located above the working table 11 and laid on a table top of the working table 11, and the punching die 24 and the four clamping blocks 23 are all disposed on the bottom plate 26, and the punching die 24, the clamping blocks 23 and the bottom plate 26 are integrally formed.

Specifically, the number of the positioning holes 241 and the number of the abdication gaps 25 are equal and correspond to each other one by one, the positioning holes 241 are communicated with the corresponding abdication gaps 25, the number of the first linear driving devices 3 and the number of the positioning holes 241 are equal and correspond to each other one by one, and the positioning holes 241 are used for allowing the punches 31 of the corresponding first linear driving devices 3 to pass through; the guide plates 42 are four and are distributed at equal intervals in the circumferential direction of the push rod 41, the guide plates 42 are in one-to-one correspondence with the punches 31, the guide plates 42 extend along the sliding directions of the corresponding punches 31, the number of the pressing columns 44 is equal to that of the guide plates 42 and is in one-to-one correspondence with the guide plates 42, the guide rods 441 of the pressing columns 44 are arranged in the guide grooves 421 of the corresponding guide plates 42 in a sliding manner, and the sliding directions of the pressing columns 44 and the corresponding punches 31 are consistent; in the second moving state of the push rod 41, the push rod 41 pushes the press stud 44 to slide toward the corresponding punch 31, and the punch 31 is fitted into the recess 442 of the corresponding press stud 44.

The four first linear driving devices 3 are operated simultaneously, and four punches 31 can be driven to punch four sides of the peripheral wall of the square tube 21 simultaneously, thereby improving punching efficiency. In addition, when the punches 31 return, the grooves 442 of the pressing columns 44 can be matched with the corresponding punches 31 and synchronously move in the same direction, and then the pressing columns 44 can press against the edges of holes punched by the corresponding punches 31 on the peripheral wall of the square tube 21, so that burrs on the edges of the holes punched by the corresponding punches 31 are removed. Thus, the four pressing posts 44 realize synchronous removal of burrs on four sides of the peripheral wall of the square tube 21, and the deburring efficiency is improved.

It will be appreciated that the locating holes 241 are coaxial with the punches 31 of the respective first linear drives 3.

The guide plate 42 extends in the radial direction of the push rod 41.

The number of the bar grooves 432 is equal to that of the guide plates 42 and corresponds to one, and the bar grooves 432 are used for the corresponding guide plates 42 to slide through.

The sleeves 433 are distributed at equal intervals in the circumferential direction of the push rod 41, the sleeves 433 and the press posts 44 are in one-to-one correspondence, the press posts 44 are slidably matched in the corresponding sleeves 433, and the openings 4331 of the sleeves 433 are used for allowing the corresponding guide plates 42 to slide through.

Wherein the relief groove 443 of the pressing post 44 is used for sliding the corresponding guide plate 42 therethrough.

It will be appreciated that the cross-sectional dimensions of the recess 442 of the ram 44 and the cross-sectional dimensions of the corresponding punch 31 are substantially equal.

Specifically, the output end of the first linear driving device 3 is elastically slidably connected with a pressing block 32 located between the square tube 21 and the punch 31, the pressing block 32 having a through hole 321 that is matched with the punch 31 and through which the punch 31 passes, the pressing block 32 being adapted to press against the peripheral wall of the square tube 21 when the punch 31 punches.

When the punch 31 punches a hole, the pressing block 32 presses the peripheral wall of the square tube 21, thereby realizing further limitation of the square tube 21. Then, the punch 31 punches the peripheral wall of the square tube 21 through the through hole 321.

The first linear driving device 3 includes a first cylinder, a cylinder of the first cylinder is mounted on the working table 11, the punch 31 is disposed on a piston rod of the first cylinder, the piston rod of the first cylinder is provided with a push block 34, the push block 34 is provided with a plurality of sliding holes extending along a sliding direction of the piston rod, the press block 32 is provided with a plurality of sliding rods 322 respectively slidably fitted in the plurality of sliding holes, and a fourth spring disposed in the sliding holes is connected between the sliding rods 322 and the push block 34.

The working table 11 is provided with a supporting frame 112 above the working table, the second linear driving device 4 includes a second cylinder, a cylinder of the second cylinder extends along the height direction of the frame 1 and is mounted on the supporting frame 112, and the push rod 41 is coaxially disposed on a piston rod of the second cylinder.

In order to avoid deformation of the press stud 44 when pressing burrs at the hole edges of the square pipe 21, embodiment 2 is also provided.

As shown in fig. 9-13, in embodiment 2, on the basis of embodiment 1, the punching die 24 includes a body 242 and a plate set 243, the body 242 is disposed above the table 11, and the peripheral wall of the body 242 is provided with positioning grooves 2421 corresponding to the four abdicating gaps 25 one by one, the body 242 has an inner cavity 2425, and when the square tube 21 and the punching die 24 are separated, the positioning grooves 2421 are communicated with the inner cavity 2425 and the corresponding abdicating gaps 25. The plate group 243 and the installation grooves 2421 are equal in number and correspond to each other one by one, the plate group 243 comprises a first baffle 2431 and a second baffle 2432 which are slidably arranged in the corresponding installation grooves 2421 along the height direction of the frame 1, the first baffle 2431 and the second baffle 2432 are opposite to each other in the height direction of the frame 1, a first spring 244 is connected between the second baffle 2432 and the body 242, the first baffle 2431 is provided with a first arc-shaped hole 24311, the second baffle 2432 is provided with a second arc-shaped hole 24321 communicated with the first arc-shaped hole 24311, the first arc-shaped hole 24311 and the second arc-shaped hole 24321 form a positioning hole 241, the diameter of the pressing column 44 is larger than the aperture of the positioning hole 241, and the first arc-shaped hole 24311 and the second arc-shaped hole 24321 are provided with chamfers for aligning with the pressing column 44.

The portion of the press post 44 for constituting the groove 442 is set as a convex ring 444, an inner space of the convex ring 444, that is, the groove 442, and an outer diameter of the convex ring 444, that is, a diameter of the press post 44. In order to ensure the hole forming effect of the punch 31 on the peripheral wall of the square tube 21, the difference in the hole diameters of the positioning hole 241 and the hole punched by the punch 31 is small. When the outer diameter of the designed convex ring 444 is equal to the aperture of the positioning hole 241 and the inner diameter is equal to the aperture of the hole punched by the punch 31, the convex ring 444 can pass through the inner space of the positioning hole 241 and press against the edge of the hole punched by the punch 31, thereby pressing burrs and removing burrs. However, at this time, the thickness between the inner and outer rings of the male ring 444 is small, and is easily deformed after long-term use.

In this embodiment, to reduce the deformation, the outer diameter of the convex ring 444 is designed to be larger than the aperture of the positioning hole 241, and the inner diameter is designed to be equal to the aperture of the hole punched by the punch 31. When the punch 31 is returned, the inner space of the convex ring 444 and the punch 31 are engaged and synchronously move in the same direction, the convex ring 444 contacts the chamfers of the first arc hole 24311 and the second arc hole 24321 and presses the chamfers to the outer sides of the first arc hole 24311 and the second arc hole 24321, whereby the convex ring 444 pushes the first baffle 2431 and the second baffle 2432 away from each other in the height direction of the frame 1. At this time, the space of the positioning hole 241 formed by the first arc hole 24311 and the second arc hole 24321 becomes large, and the convex ring 444 passes through the positioning hole 241 and presses against the hole edge punched by the punch 31, thereby pressing the burr and removing the burr. Therefore, the thickness of the convex ring 444 is increased in the present embodiment, so that the structural strength of the convex ring 444 is enhanced, the deformation degree of the convex ring 444 is smaller after long-term use, the replacement frequency of the convex ring 444 is reduced, and the service lives of the compression column 44 and the convex ring 444 are prolonged. In addition, in this embodiment, due to the increase in thickness of the raised ring 444, the contact area between the raised ring 444 and the edge of the hole punched by the punch 31 increases, so that the extrusion range of burrs is increased, and the deburring effect is further improved.

When the pressing post 44 and the convex ring 444 are reset, the first baffle 2431 moves downwards under the action of dead weight and resets, the second baffle 2432 moves upwards under the action of the elastic force of the first spring 244 and resets, and the first baffle 2431 and the second baffle 2432 are propped against each other up and down.

It will be appreciated that the foregoing embodiment describes the movement patterns of one set of the corresponding collar 444, the punch 31, the first baffle 2431 and the second baffle 2432, and the movement patterns of the corresponding sets of the collar 444, the punch 31, the first baffle 2431 and the second baffle 2432 are the same, and will not be repeated herein.

It is appreciated that the first barrier 2431 is positioned above the second barrier 2432.

Wherein, the opposite side walls of the installation groove 2421 in the circumferential direction of the body 242 are provided with sliding grooves 2422 extending along the height direction of the rack 1, the first baffle 2431 is provided with two first sliding strips 24312 which are respectively in sliding fit with the two sliding grooves 2422, and the second baffle 2432 is provided with two second sliding strips 24322 which are respectively in sliding fit with the two sliding grooves 2422.

Wherein, the upper ends of the setting grooves 2421 and the sliding grooves 2422 are opened, the punching die 24 further comprises a blocking plate 245 corresponding to the four setting grooves 2421 one by one, the blocking plate 245 closes the upper ends of the corresponding setting grooves 2421, blocking blocks 2451 are arranged at two ends of the blocking plate 245, the two blocking blocks 2451 are respectively arranged in the two sliding grooves 2422 of the setting grooves 2421 and close the upper ends of the sliding grooves 2422, the punching die further comprises bolts corresponding to the blocking blocks 2451 one by one, the bolts penetrate through the body 242 and the corresponding blocking blocks 2451, and one ends of the bolts protrude out of the body 242 and are screwed with nuts. Thus, the blocking plate 245 and the blocking block 2451 achieve the closure of the seating groove 2421 and the sliding groove 2422, preventing the first and second shutters 2431 and 2432 from sliding out of the upper end of the seating groove 2421. Meanwhile, the bolt and the nut achieve the detachable effect between the blocking block 2451 and the body 242, so that the blocking block 2451 and the blocking plate 245 can be conveniently taken down, and the first baffle 2431 and the second baffle 2432 can be conveniently replaced.

Specifically, the punching die 24 further includes holding frames 246 equal to and corresponding to the number of the plate groups 243 one by one, the holding frames 246 are elastically connected with the body 242, the holding frames 246 have two clamping bars 2461 symmetrical to each other in the height direction of the frame 1, the plate groups 243 are clamped between the two clamping bars 2461 of the corresponding holding frames 246, the free ends of the clamping bars 2461 are provided with inclined surfaces 24611 facing the inner sides of the corresponding plate groups 243, the holding frames 246 have wedge-shaped blocks 2462 located in the inner cavities 2425 of the body 242, the wedge-shaped blocks 2462 are located above the limiting blocks 22 and adjacent to the limiting blocks 22, the limiting plates 43 are matched with the inner circumferences of the body 242, and in the second moving state, the push rods 41 are stopped by the limiting blocks 22 and force the wedge-shaped blocks 2462 to move to the outer sides of the body 242, and the clamping bars 2461 are separated from the plate groups 243.

When the punch 31 punches a hole, the plate group 243 is defined between the two clamping bars 2461 of the corresponding clamping frame 246, whereby when the impact force of the punch 31 partially acts on the first and second shutters 2431 and 2432, the first and second shutters 2431 and 2432 cannot shake up and down under the restriction of the two clamping bars 2461, and the stability of the positioning hole 241 between the first and second shutters 2431 and 2432 is ensured, thereby ensuring the hole forming effect and the hole forming quality of the punch 31 on the square tube 21.

After punching, when the push rod 41 is adjacent to the wedge 2462 and drives the limiting plate 43 to move downwards continuously, the limiting plate 43 and the wedge 2462 are in extrusion contact and push the wedge 2462 to gradually move away from the outer side of the body 242, and meanwhile, the clamping rod 2461 is gradually separated from the plate group 243 under the drive of the wedge 2462, and at the moment, the convex ring 444 of the pressing column 44 is in contact with the inner circumferential surface of the body 242. When the stopper plate 43 is stopped against the stopper 22, the wedge 2462 is moved to the limit position, the clamp lever 2461 and the plate group 243 are completely separated, and the restriction of the clamp lever 2461 to the plate group 243 is released. At this time, when the collar 444 and the punch 31 are engaged and contacted with the chamfer, the first and second shutters 2431 and 2432 can be pressed outward, the first and second shutters 2431 and 2432 are separated from each other in the height direction of the frame 1, and the clamping frame 246 is used for giving way to the separation of the first and second shutters 2431 and 2432.

Wherein, the body 242 is provided with sliding cavities corresponding to the clamping frames 246 in number, the sliding cavities extend in the circumferential direction of the body 242, the clamping frames 246 are slidably engaged in the sliding cavities, the sliding cavities include a first sliding groove 2423 and a second sliding groove 2424 extending in the circumferential direction of the body 242, two clamping rods 2461 of the clamping frames 246 are slidably engaged in the first sliding groove 2423, and the wedge 2462 is slidably engaged in the second sliding groove 2424.

As can be appreciated, one of the two slide grooves 2422 of the first slide groove 2423 and the seating groove 2421 communicates.

Wherein, the clamping frame 246 and the body 242 are connected with two second springs 247 in the first sliding groove 2423, and the two second springs 247 are spaced apart in the height direction of the frame 1.

As can be appreciated, when the push rod 41 and the limiting plate 43 are reset, the clamping frame 246 is reset under the action of the second spring 247, and the inclined surfaces 24611 of the two clamping rods 2461 are used for guiding the first baffle 2431 and the second baffle 2432 to reset, so that the first baffle 2431 and the second baffle 2432 are prevented from deviating from the original positions.

The limiting blocks 22 are four and are all installed in the inner cavity 2425 of the body 242, the limiting blocks 22 and the wedge-shaped blocks 2462 are in one-to-one correspondence, and the wedge-shaped blocks 2462 are adjacent to the corresponding limiting blocks 22.

Specifically, the first barrier 2431 and the second barrier 2432 in the panel set 243 are elastically connected.

When the first and second shutters 2431 and 2432 are reset, the elastic force between the first and second shutters 2431 and 2432 accelerates the reset speed of both. In addition, the first baffle 2431 is pulled back by the elastic force and the gravity together, so that the restoring force is larger, the blocking effect of the chips on the first baffle 2431 is weakened, and the restoring effect of the first baffle 2431 is ensured.

Wherein, the first baffle 2431 is provided with two sliding holes 24313 spaced apart in the circumferential direction of the body 242, the sliding holes 24313 extend in the height direction of the frame 1, the second baffle 2432 is provided with two sliding rods 24323 respectively slidably fitted in the two sliding holes 24313, and a third spring 2433 positioned in the sliding hole 24313 is connected between the sliding rod 24323 and the first baffle 2431.

Specifically, the metal pipe punching machine further comprises a material guiding pipe 5, the workbench 11 is provided with a through hole 111 communicated with the inner cavity 2425 of the body 242, a first end of the material guiding pipe 5 is communicated with the inner cavity 2425 of the body 242 through the through hole 111, and a second end of the material guiding pipe 5 is suitable for blanking of the outer square pipe 21.

The punched blanking of the square tube 21 falls into the inner cavity 2425 of the body 242 through the positioning hole 241, and then falls into the material guiding tube 5 through the through hole 111, and the material guiding tube 5 is used for guiding the blanking and discharging the blanking out of the material guiding tube 5 through the second end.

It will be appreciated that the feed pipe 5 is disposed obliquely.

As can be appreciated, the interior cavity 2425 of the body 242 extends through the floor 26 and communicates with the throughbore 111.

Specifically, the portion of the mounting groove 2421 located below the second baffle 2432 forms a sliding groove 24211, the plurality of first springs 244 are all located in the sliding groove 24211, the punching die 24 further includes cover plates 248 corresponding to the sliding grooves 24211 one by one, the cover plates 248 are located in the inner cavities 2425 of the body 242 and close the corresponding sliding grooves 24211, and the cover plates 248 are connected with the body 242.

The cover plate 248 is used for preventing the falling material and the scraps in the inner cavity 2425 of the body 242 from entering the sliding groove 24211, so as to influence the sliding effect of the second baffle 2432, and ensure the sliding reliability of the second baffle 2432.

Wherein the plurality of first springs 244 are equally spaced apart along the circumferential direction of the body 242.

To avoid debris from affecting the return effect of the first 2431 and second 2432 baffles, embodiment 3 is also provided.

As shown in fig. 14 and 15, in embodiment 3, on the basis of embodiment 2, a containing area is formed between two adjacent press columns 44, the limiting plate 43 is provided with ventilation pipes 434 which are equal in number and in one-to-one correspondence with the containing area, the ventilation pipes 434 are placed in the corresponding containing areas and two pipe orifices are respectively close to the two adjacent press columns 44, the output end of the second linear driving device 4 is provided with an annular pipe 45 extending along the circumferential direction of the push rod 41, a hose 46 is communicated between each of the plurality of ventilation pipes 434 and the annular pipe 45, and the metal pipe punching machine further comprises an air pump which is mounted at the output end of the second linear driving device 4 and is communicated with the annular pipe 45.

When the groove 442 of the pressing column 44 is matched with the punch 31, the pressing column 44 presses the first baffle 2431 and the second baffle 2432 outwards, the air pump operates and pumps air from the annular tube 45, and through the transmission of the hose 46, the orifice of the ventilation pipeline 434 sucks the scraps at the gap between the first baffle 2431 and the second baffle 2432, so that the scraps are prevented from falling into the gap area between the first baffle 2431 and the second baffle 2432, and therefore the first baffle 2431 and the second baffle 2432 can be tightly closed when reset, and the reliability of the positioning hole 241 is guaranteed.

Wherein, the two ends of the air conduit 434 are fixedly connected with two adjacent sleeves 433, respectively.

The support frame 112 has four struts 1121 equally spaced along the circumference of the second cylinder, the struts 1121 extend along the height direction of the frame 1, the metal pipe punching machine further includes a sliding table 6, the sliding table 6 has sliding drums 61 corresponding to the struts 1121 in number and one-to-one, the sliding drums 61 are slidably sleeved on the corresponding struts 1121, and the sliding table 6 is fixedly connected with a piston rod of the second cylinder and located above the push rod 41.

Wherein, the annular pipe 45 sets up in the platform 6 that slides, and the air pump is installed in the platform 6 that slides.

The ventilation duct 434 is located below the sliding table 6, and the hose 46 slides through the sliding table 6.

In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings are merely for convenience in describing the present invention and simplifying the description, and do not indicate or imply that the device or element being referred to must have a specific orientation, be configured and operated in a specific orientation, and therefore should not be construed as limiting the present invention.

Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include at least one such feature. In the description of the present invention, the meaning of "plurality" means at least two, for example, two, three, etc., unless specifically defined otherwise.

While embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are illustrative and not to be construed as limiting the invention, and that variations, modifications, alternatives and variations may be made to the above embodiments by one of ordinary skill in the art within the scope of the invention.

Claims

1. A metal tube piercing press, comprising:

a frame (1), the frame (1) having a table (11);

the limiting assembly (2) is arranged on the workbench (11) and is suitable for limiting the square tube (21);

a first linear driving device (3), wherein the first linear driving device (3) is arranged on the workbench (11), and a punch (31) which faces the square tube (21) and is suitable for punching the square tube is arranged at the output end of the first linear driving device;

The second linear driving device (4), the second linear driving device (4) is arranged above the workbench (11), a push rod (41) extending along the height direction of the frame (1) is arranged at the output end of the second linear driving device, a guide plate (42) is arranged on the peripheral surface of the push rod (41), and an inclined guide groove (421) is formed in the guide plate (42); and

limiting plate (43), limiting plate (43) with push rod (41) are followed limiting plate (43) are followed the direction of height limit sliding connection of frame (1), limiting plate (43) are equipped with slidable clamp column (44), clamp column (44) with the slip direction of drift (31) is unanimous, clamp column (44) are equipped with slide wear to locate guide bar (441) in guide slot (421), clamp column (44) deviate from the terminal surface of push rod (41) is equipped with recess (442), spacing subassembly (2) have with limiting plate (43) upper and lower correspondence is located stopper (22) of side pipe (21), push rod (41) have first mobile state and second mobile state the first mobile state, push rod (41) drive clamp column (44) with limiting plate (43) move down in the second mobile state, drift (31) are in on the perisporium of side pipe (21) and wear to locate in the hole of punching a hole, push rod (43) up to push rod (31) towards stopper (42).

2. A metal tube punching machine according to claim 1, characterized in that the limit assembly (2) comprises:

the clamping blocks (23) are distributed in a rectangular shape, two adjacent clamping blocks (23) are symmetrical to each other, the clamping blocks (23) are arranged above the workbench (11) and are L-shaped in cross section, and the corner areas of the clamping blocks (23) form limiting spaces; and

the punching die (24), punching die (24) are square tubular structure and follow the direction of height of frame (1) extends, punching die (24) are located the top of workstation (11) and four corners of it are placed in respectively four in spacing space of clamp block (23), square pipe (21) are suitable for the cover to be arranged in the outer peripheral face of punching die (24) and be limited in clamp block (23) with between punching die (24), adjacent two form between clamp block (23) and give way space (25), the perisporium of punching die (24) be equipped with locating hole (241) that give way space (25) intercommunication, push rod (41) are in during the second mobile state, drift (31) sliding insert are located locating hole (241), locating hole (241) with post (44) coaxial.

3. The metal pipe punching machine according to claim 2, characterized in that the number of the positioning holes (241) and the relief spaces (25) are equal and in one-to-one correspondence, the positioning holes (241) are communicated with the corresponding relief spaces (25), the number of the first linear driving devices (3) and the positioning holes (241) are equal and in one-to-one correspondence, and the positioning holes (241) are used for the punches (31) of the corresponding first linear driving devices (3) to pass through; the guide plates (42) are four and are distributed at intervals in the circumferential direction of the push rod (41), the guide plates (42) are in one-to-one correspondence with the punches (31), the guide plates (42) extend along the sliding directions of the corresponding punches (31), the number of the pressing columns (44) is equal to that of the guide plates (42) and are in one-to-one correspondence with each other, the guide rods (441) of the pressing columns (44) are slidably arranged in the guide grooves (421) of the corresponding guide plates (42) in a penetrating manner, and the sliding directions of the pressing columns (44) and the corresponding punches (31) are consistent; the push rod (41) pushes the pressing column (44) to slide towards the corresponding punch (31) when the push rod (41) is in the second moving state, and the punch (31) is matched in the groove (442) of the corresponding pressing column (44).

4. A metal pipe punch as claimed in claim 3, wherein the punching die (24) comprises:

the body (242), the body (242) is set above the work table (11) and its circumference wall has setting grooves (2421) corresponding to four space (25) one by one, the body (242) has inner cavity (2425), when the square tube (21) and the punching die (24) are separated, the setting grooves (2421) are communicated with the inner cavity (2425) and the corresponding space (25); and

the integrated die comprises a plate group (243), wherein the plate group (243) and the placement grooves (2421) are equal in number and correspond to each other one by one, the plate group (243) comprises a first baffle (2431) and a second baffle (2432) which are slidably arranged in the corresponding placement grooves (2421) along the height direction of the frame (1), the first baffle (2431) and the second baffle (2432) are opposite in the height direction of the frame (1), a first spring (244) is connected between the second baffle (2432) and the body (242), the first baffle (2431) is provided with a first arc-shaped hole (24311), the second baffle (2432) is provided with a second arc-shaped hole (24321) communicated with the first arc-shaped hole (24311), the first arc-shaped hole (24311) and the second arc-shaped hole (24321) form a positioning hole (241), the diameter of a pressing column (44) is larger than the aperture of the positioning hole (241), and the first arc-shaped hole (3562) and the second arc-shaped column (24311) are provided with a chamfer (24321).

5. The metal tube punching machine according to claim 4, characterized in that the punching die (24) further comprises clamping frames (246) which are equal in number and in one-to-one correspondence to the plate groups (243), the clamping frames (246) and the bodies (242) being elastically connected, the clamping frames (246) having two clamping bars (2461) which are mutually symmetrical in the height direction of the frame (1), the plate groups (243) being clamped between the two clamping bars (2461) of the respective clamping frames (246), the free ends of the clamping bars (2461) being provided with inclined surfaces (24611) which face the inner side of the respective plate groups (243), the clamping frames (246) having wedge-shaped blocks (2462) which are located in the inner cavities (2425) of the bodies (242), the wedge-shaped blocks (2462) being located above the limiting blocks (22) and adjacent to the limiting blocks (22), the limiting plates (43) and the inner circumferences of the bodies (242) being matched, the pushing bars (41) being forced to move toward the outer sides of the limiting blocks (2461) when the second limiting blocks (242) are moved toward the outer sides (24243).

6. The metal tube punching machine of claim 5, characterized in that the first baffle (2431) and the second baffle (2432) in the plate set (243) are elastically connected.

7. The metal pipe punching machine as claimed in claim 5, characterized in that a containing area is formed between two adjacent press posts (44), the limiting plate (43) is provided with ventilation pipes (434) which are equal in number and correspond to the containing area one by one, the ventilation pipes (434) are arranged in the corresponding containing area, two pipe orifices are respectively close to the two adjacent press posts (44), the output end of the second linear driving device (4) is provided with an annular pipe (45) extending along the circumferential direction of the push rod (41), a hose (46) is communicated between each of the ventilation pipes (434) and the annular pipe (45), and the metal pipe punching machine further comprises an air pump which is arranged at the output end of the second linear driving device (4) and is communicated with the annular pipe (45).

8. A metal pipe punching machine according to claim 1 or 3, characterized in that the output end of the first linear drive means (3) is elastically slidingly connected with a press block (32) located between the square pipe (21) and the punch (31), the press block (32) having a through hole (321) matching the punch (31) and for the punch (31) to pass through, the press block (32) being adapted to press against the peripheral wall of the square pipe (21) when the punch (31) punches.

9. The metal tube punching machine according to claim 4, characterized in that it further comprises a feed pipe (5), said work table (11) being provided with a through hole (111) communicating with said inner cavity (2425) of said body (242), a first end of said feed pipe (5) being in communication with said inner cavity (2425) of said body (242) through said through hole (111), a second end of said feed pipe (5) being adapted to discharge the blanking of said square tube (21).

10. The metal tube punching machine as claimed in claim 4, characterized in that a portion of the seating groove (2421) located under the second baffle plate (2432) constitutes a sliding groove (24211), the first springs (244) are plural and located in the sliding groove (24211), the punching die (24) further includes cover plates (248) which are equal in number and correspond one to the sliding grooves (24211), the cover plates (248) are located in the inner cavities (2425) of the body (242) and close the corresponding sliding grooves (24211), and the cover plates (248) are connected to the body (242).