CN111923348A

CN111923348A - Automatic thread demoulding mould

Info

Publication number: CN111923348A
Application number: CN202010863771.9A
Authority: CN
Inventors: 张航媛; 蔡凯; 陈爱平
Original assignee: Yonggao Co Ltd
Current assignee: Ad Pipeline Zhejiang Co ltd
Priority date: 2020-08-25
Filing date: 2020-08-25
Publication date: 2020-11-13
Anticipated expiration: 2040-08-25
Also published as: CN111923348B

Abstract

The invention provides an automatic thread demoulding mould, and belongs to the technical field of machinery. It has solved the problem that current thread demoulding utensil is inefficient. The lower die of the die is provided with a sliding block, a first driving gear is arranged in the sliding block, a first insert is arranged on the first driven gear and positioned axially, the first driven gear is sleeved outside a corresponding first insert, the first driving gear can drive the first insert to rotate through the first driven gear, a first core is arranged on the first insert in an axial positioning mode, a second driving gear is arranged in the lower die, a second insert is arranged on the second driven gear and positioned axially, the second driven gear is sleeved outside the corresponding second insert, the second driving gear can drive the second insert to rotate through the second driven gear, a second core is arranged on the second insert in an axial positioning mode, the first insert and the first core are arranged in the horizontal direction, and the second insert and the second core are arranged in the vertical direction. The automatic thread demoulding mould has the advantages of high demoulding speed and high working efficiency.

Description

Automatic thread demoulding mould

Technical Field

The invention belongs to the technical field of machinery, and relates to an automatic thread demoulding mould.

Background

The plastic pipe fitting is widely applied to water supply and drainage of buildings and has various styles, such as straight-through, elbow, tee joint, four-way joint and the like. The plastic pipe fitting is generally formed by injection molding of plastic materials, and in order to facilitate connection and improve the connection firmness and tightness, threads are arranged at two ends of the existing plastic pipe fitting.

For example, chinese patent literature discloses a double-head female thread elbow die [ application number: 200920198428.6, respectively; authorization notice number: CN201511475U ], which comprises an upper mold plate and a lower mold plate, wherein the upper mold plate is connected with a movable mold plate, a fixed mold cavity is arranged in the fixed mold plate, a mold foot and a top plate are arranged on the lower mold plate, a movable mold plate is arranged on the mold foot, a movable mold insert is arranged on the movable mold plate, four rotary mold cavities are respectively arranged on the movable mold plate, each of the four rotary mold cavities has a rotating device, four mold cavities are respectively formed between the four rotary mold cavities and the fixed mold core, each of the four mold cavities has a unique forming elbow, the forming elbows have automatic ejection mechanisms, the forming elbows respectively penetrate through the elbow cores, one ends of the elbow cores are fixedly connected in a frame, the frame is arranged on the movable mold plate, a thread core is arranged in the frame, the head of the thread core is matched with the opening of the forming elbow, a gear is arranged on the.

According to the double-head internal thread elbow die with the structure, firstly, a motor drives a rotating tooth to rotate, the rotating tooth drives a gear to rotate, the gear rotates to drive a thread core to rotate and exit, and internal threads of an elbow are demoulded; and then the rotating device drives the rotating cavity to rotate, the elbow is driven to be separated from the elbow core, and finally the ejection mechanism automatically ejects the elbow from the rotating cavity, so that the elbow demoulding is completed. The double-head internal thread elbow die with the structure has the advantages of more steps, slower demoulding speed and insufficient production efficiency.

Disclosure of Invention

The invention aims to provide an automatic thread demoulding mould aiming at the problems in the prior art, and solves the technical problems of improving demoulding speed and improving working efficiency.

The purpose of the invention can be realized by the following technical scheme: an automatic thread demoulding die comprises an upper die and a lower die, wherein a plurality of forming cavities are formed between the upper die and the lower die after die assembly is carried out, and a sliding block capable of translating is arranged on the lower die, and the automatic thread demoulding die is characterized in that a first driving gear, a plurality of first driven gears and a plurality of first inserts are arranged in the sliding block in an axial positioning mode, the first driven gears are sleeved outside the corresponding first inserts, the first driving gear can drive the first inserts to rotate through the first driven gears, a first core is axially positioned in the first inserts, the inner ends of the first cores are convexly arranged outside the first inserts, the inner ends of the first inserts and the inner ends of the first cores can extend into the corresponding forming cavities, a second driving gear, a plurality of second driven gears and a plurality of second inserts are arranged in the lower die, the second driven gears are sleeved outside the corresponding second inserts, the second driving gear can drive the second insert to rotate through the second driven gear, a second core is axially positioned in the second insert, the inner end of the second core is convexly arranged outside the second insert, the inner ends of the second insert and the second core can extend into the corresponding forming cavity, the first insert and the first core are arranged along the horizontal direction, the second insert and the second core are arranged along the vertical direction, the first insert, the first core, the second insert and the second core are arranged in a one-to-one correspondence mode, and the inner end of the first core is matched with the inner end of the second core.

The automatic thread demoulding die is mainly used for manufacturing a 90-degree elbow, and outer threads matched with inner threads needing to be processed at two ends of the 90-degree elbow are arranged on the outer side walls of the inner ends of the first insert and the second insert. After the upper die and the lower die are assembled, the inner ends of the first insert, the first core, the second insert and the second core are embedded into the corresponding forming cavities, the inner end of the first core and the inner end of the second core are in fit, then injection molding is carried out on the first core and the second core into the forming cavities, and the die is opened after solidification. The slider outwards translates and drives first insert and first core and outwards removes, and at this in-process, first driving gear is rotatory to drive first insert rotatory through first driven gear to make first insert can be rotatory relative to the work piece, make first insert and work piece can not block, first insert outwards removes at rotatory in-process, realizes that the work piece is automatic to take off the screw thread. After the first insert and the first core move outwards to be separated from the workpiece, the second drive gear rotates to drive the second insert to rotate through the second driven gear, the workpiece is embedded into a forming cavity of the lower die part at the moment, namely the workpiece and the lower die are positioned circumferentially, the second insert rotates to enable the workpiece and the second insert to move relatively, and the vertical position of the second insert is unchanged, so that the workpiece slowly separates upwards in the rotating process of the second insert until the workpiece is separated from the second insert, the workpiece is automatically stripped, and then the workpiece is pushed downwards through the ejector rod. The automatic thread demoulding die realizes automatic thread demoulding at two ends of a workpiece, has high automation degree and few steps, improves demoulding speed and improves working efficiency. Simultaneously, the automatic thread demoulding mould can process a plurality of workpieces at one time, and can demould the workpieces simultaneously, so that the demoulding speed is increased, and the working efficiency is improved. And through a plurality of first driven gears and second driven gear's setting, make this automatic take off driving piece quantity of screw thread mould can great reduction, simple more of structure, the driving piece is arranged also can be more reasonable.

In foretell automatic take off screw thread mould, wear to be equipped with in the slider and be used for the first driving shaft that links to each other with the driving piece, first driving gear cover is established outside first driving shaft, still be equipped with at least one third driven gear in the slider, wear to be equipped with the lead screw in the third driven gear, the lead screw links to each other with the slider, first driving shaft rotatory energy drives the slider translation through first driving gear, third driven gear and lead screw. Utilize the structure of lead screw slider, can drive the slider translation when making first driving gear rotatory, improve this automatic stability when taking off the screw thread mould and take off the screw thread.

In the above automatic thread demoulding mould, at least one fourth driven gear is arranged in the slide block, the fourth driven gear is respectively connected with the corresponding first driven gear and the corresponding third driven gear, and the first driving shaft can drive the slide block to translate through the first driving gear, the first driven gear, the fourth driven gear, the third driven gear and the screw rod. The internal cavity of rational utilization slider makes first driving gear, first driven gear, fourth driven gear and third driven gear's overall arrangement more reasonable, realizes automatic taking off the screw thread when the slider outwards removes.

In foretell automatic thread mould that takes off, wear to be equipped with second driving shaft and a plurality of driven shafts in the lower mould, the outer end at the second driving shaft is established to the second driving gear cover, the inner pot head of second driving shaft is equipped with fifth driven gear, the both ends of driven shaft are equipped with sixth driven gear and seventh driven gear respectively, the second driving gear can drive the second through second driving shaft, fifth driven gear, sixth driven gear, driven shaft, seventh driven gear and second driven gear and insert rotatoryly. The space in the lower die is reasonably utilized, so that the layout of each shaft and each gear is more reasonable, the second driving gear rotates to realize the rotation of the second insert, the second insert and the workpiece move relatively, and the workpiece automatically realizes thread removal.

In foretell automatic thread demoulding mould, first core and second core all include the shaping portion and are shaft-like location portion, the inner of location portion links firmly with the shaping portion, the outer end of location portion has linked firmly the fastener, the shaping portion protrusion of first core sets up outside first inserting, the shaping portion protrusion of second core sets up outside the second is inserted, rotates the fastener enables the inner of first inserting and second inserting supports respectively and leans on the shaping portion that corresponds. The forming part is used for filling the space inside the workpiece, the positioning part plays a role in connecting and supporting, the fastener is matched with the forming part, the first core and the first insert are axially positioned, and the second core and the second insert are axially positioned.

In the above automatic thread removing mold, the inner end surface of the first core forming portion has a positioning groove which is concavely arranged, the inner end surface of the second core forming portion has a positioning projection which is convexly arranged, and the positioning projection can be embedded into the corresponding positioning groove. The positioning groove is matched with the positioning lug, so that the stability of the first core and the second core in matching is improved, the first core and the second core cannot deviate from a set position in machining, the machining precision of a workpiece is improved, and the workpiece cannot be clamped in the process of thread removal.

In the above automatic thread demoulding die, the first driven gear sleeve is fixed at the end of the outer end of the first insert, the outer side wall of the inner end of the first insert is conical, the second driven gear sleeve is fixed at the end of the outer end of the second insert, and the outer side wall of the inner end of the second insert is conical. The outer side wall of the inner end of the first insert is conical, so that the first insert is embedded in place, and meanwhile, the structure ensures that the first insert is smooth when retreating and has good stability when the thread is removed; the outer side wall of the inner end of the second insert is conical, so that the second insert is embedded in place, and meanwhile, the structure enables the second insert to be smooth when exiting and has good stability when disengaging threads.

In the automatic thread demoulding mould, a first bearing is arranged between each first insert and each sliding block, and the first insert is axially positioned with the sliding block through the first bearing. The first bearing enables the first insert to rotate smoothly, and the first bearing and the sliding block are axially positioned by the first bearing, so that the first bearing has multiple functions, and the number of parts can be reduced.

In the automatic thread demoulding mould, a second bearing is arranged between each second insert and the lower mould, and the second insert is axially positioned with the lower mould through the second bearing. The second insert is smoothly rotated by the aid of the second bearing, and the second bearing and the lower die are axially positioned by the aid of the second bearing, so that the first bearing is multifunctional, and the number of parts can be reduced.

In the automatic thread demoulding mould, a third bearing is arranged between the first insert and the first core, the third bearing is positioned at the end part of the inner end of the first insert, a fourth bearing is arranged between the second insert and the second core, and the fourth bearing is positioned at the end part of the inner end of the second insert. The third bearing enables the first insert to smoothly rotate relative to the first core, and the fourth bearing enables the second insert to smoothly rotate relative to the second core.

Compared with the prior art, the automatic thread demoulding mould provided by the invention has the following advantages:

1. this automatic take off screw thread mould realizes taking off the screw thread of work piece one end when making the slider translation outwards through a driving piece, realizes making the work piece automatic slow shifting up when the screw thread is taken off to the work piece other end through another driving piece, makes things convenient for the work piece unloading, improves drawing of patterns speed, improves work efficiency.

2. This automatic take off thread mould once can process a plurality of work pieces, and demold a plurality of work pieces simultaneously, improves drawing of patterns speed, improves work efficiency, and through a plurality of first driven gear and second driven gear's setting, the reduction that makes this automatic take off thread mould's driving piece quantity can be great moreover, and the structure is simpler, and the driving piece is arranged also can be more reasonable.

Drawings

FIG. 1 is a transverse sectional view of the whole structure of the automatic thread stripping die.

Fig. 2 is a longitudinal sectional view of the whole structure of the automatic thread stripping die.

FIG. 3 is a schematic view of the connection structure of the forming cavity of the automatic thread-removing mold and the first driving gear inside the slide block.

FIG. 4 is a schematic view showing a connection structure of a second driving gear and the like in the lower die of the automatic thread removing die.

FIG. 5 is a schematic view showing the overall structure of the first core of the automatic thread stripping mold.

Fig. 6 is a schematic view of the connection structure of the first driving gear, the first driven gear, etc. of the automatic thread stripping die.

In the figure, 1, an upper die; 2. a lower die; 3. a molding cavity; 4. a slider; 5. a first drive gear; 6. a first driven gear; 7. a first insert; 8. a first core; 9. a second driving gear; 10. a second driven gear; 11. a second insert; 12. a second core; 13. a first drive shaft; 14. a third driven gear; 15. a screw rod; 16. a fourth driven gear; 17. a second driving shaft; 18. a driven shaft; 19. a fifth driven gear; 20. a sixth driven gear; 21. a seventh driven gear; 22. a molding section; 23. a positioning part; 24. a positioning groove; 25. positioning the bump; 26. a first bearing; 27. a second bearing; 28. a third bearing; 29. a fourth bearing; 30. and (5) a workpiece.

Detailed Description

The following are specific embodiments of the present invention and are further described with reference to the drawings, but the present invention is not limited to these embodiments.

As shown in fig. 1, 2 and 3, the automatic thread stripping die includes an upper die 1, a lower die 2, a slider 4, a first driving gear 5, a first driven gear 6, a first insert 7, a first core 8, a second driving gear 9, a second driven gear 10, a second insert 11, a second core 12, a first driving shaft 13, a third driven gear 14, a screw rod 15, a fourth driven gear 16, a second driving shaft 17, a driven shaft 18, a fifth driven gear 19, a sixth driven gear 20 and a seventh driven gear 21.

The number of the slide blocks 4 is two, in the embodiment, eight molding cavities 3 are formed between the upper die 1 and the lower die 2 after die assembly, the number of the first driven gears 6, the first inserts 7, the first cores 8, the second driven gears 10, the second inserts 11 and the second cores 12 is eight, the number of the third driven gears 14 and the screw rods 15 is four, the number of the fourth driven gears 16 is four, the number of the driven shafts 18, the sixth driven gears 20 and the seventh driven gears 21 is two, in actual production, the number of the molding cavities 3, the first driven gears 6, the first inserts 7, the first cores 8, the second driven gears 10, the second inserts 11 and the second cores 12 can be four or sixteen, the number of the fourth driven gears 16 is two or eight, and the number of the driven shafts 18, the sixth driven gears 20 and the seventh driven gears 21 is one or four.

The first driving gear 5, the first driven gear 6, the third driven gear 14 and the fourth driven gear 16 are all positioned in the slide block 4, the first insert 7 and the first core 8 are both partially positioned in the slide block 4, and the first insert 7 and the first core 8 are both arranged along the horizontal direction. The outer side wall of the first insert 7 is provided with a first step surface, the inner side wall of the slide block 4 is provided with a second step surface, a first bearing 26 is arranged between each first insert 7 and the slide block 4, and two sides of each first bearing 26 are respectively abutted against the first step surface and the second step surface to axially position the first insert 7 and the slide block 4.

A first driving shaft 13 penetrates through the sliding block 4, the outer end of the first driving shaft 13 is connected with the motor, the first driving gear 5 is sleeved outside the first driving shaft 13, the first driven gears 6 are sleeved at the end parts of the outer ends of the corresponding first inserts 7, the first driving gear 5 is directly connected with the two first driven gears 6 positioned in the middle, the two first driven gears 6 are respectively connected with the two first driven gears 6 on the outer side through fourth driven gears 16, the two fourth driven gears 16 are respectively connected with the corresponding third driven gears 14, lead screws 15 penetrate through the third driven gears 14, the lead screws 15 are connected with the sliding block 4, as shown in fig. 6, the first driving shaft 13 can directly drive the two first driven gears 6 to rotate through the first driving gear 5, then the corresponding first driven gears 6 can be respectively driven to rotate through the fourth driven gears 16, and the first driving shaft 13 rotates through the first driving gear 5, The first driven gear 6, the fourth driven gear 16, the third driven gear 14 and the screw rod 15 drive the sliding block 4 to translate.

The first core 8 and the second core 12 both comprise a forming part 22 and a rod-shaped positioning part 23, the inner end of the positioning part 23 is fixedly connected with the forming part 22, the outer end of the positioning part 23 is fixedly connected with a fastener, the forming part 22 of the first core 8 is convexly arranged outside the first insert 7, the inner end of the first insert 7 can be abutted against the corresponding forming part 22 by rotating the fastener such as a screw cap, the fastener is abutted against the slide block 4, the first insert 7 and the first core 8 are axially positioned through the fastener and the forming part 22, the inner ends of the first insert 7 and the first core 8 can both extend into the corresponding forming cavity 3, the outer side wall of the inner end of the first insert 7 is conical, a third bearing 28 is arranged between the first insert 7 and the first core 8, and the third bearing 28 is positioned at the end part of the inner end of the first insert 7.

As shown in fig. 4, the second driven gear 10 is sleeved outside the corresponding second insert 11, the second driving shaft 17 and the driven shaft 18 penetrate through the lower die 2, the second driving gear 9 is sleeved at the outer end of the second driving shaft 17, the fifth driven gear 19 is sleeved at the inner end of the second driving shaft 17, the sixth driven gear 20 and the seventh driven gear 21 are respectively sleeved at two ends of the driven shaft 18, and the second driving gear 9 can drive the second insert 11 to rotate through the second driving shaft 17, the fifth driven gear 19, the sixth driven gear 20, the driven shaft 18, the seventh driven gear 21 and the second driven gear 10.

The forming part 22 of the second core 12 is convexly arranged outside the second insert 11, the second insert 11 and the second core 12 are both arranged along the vertical direction, the inner end of the second insert 11 can abut against the corresponding forming part 22 by rotating a fastener such as a screw cap, the fastener abuts against the lower die 2, the second insert 11 and the second core 12 are axially positioned by the fastener and the forming part 22, the inner ends of the second insert 11 and the second core 12 can both extend into the corresponding forming cavity 3, and the outer side wall of the inner end of the second insert 11 is conical. A second bearing 27 is arranged between each second insert 11 and the lower die 2, and the second insert 11 is axially positioned with the lower die 2 through the second bearing 27. Between the second insert 11 and the second core 12 is a fourth bearing 29, the fourth bearing 29 being located at the end of the inner end of the second insert 11.

The first insert 7, the first core 8, the second insert 11 and the second core 12 are arranged in a one-to-one correspondence. As shown in fig. 5, the inner end surface of the molding portion 22 of the first core 8 has a positioning groove 24 which is concavely arranged, and the inner end surface of the molding portion 22 of the second core 12 has a positioning projection 25 which is convexly arranged, and the positioning projection 25 can be inserted into the corresponding positioning groove 24.

After the upper die 1 and the lower die 2 are closed, the inner ends of the first insert 7, the first core 8, the second insert 11 and the second core 12 are embedded into the corresponding molding cavity 3, the positioning lug 25 of the second core 12 is embedded into the positioning groove 24 of the first core 8, then injection molding is carried out on the first core into the molding cavity 3, and the die is opened after solidification. In the process, the fourth driven gear 16 drives the third driven gear 14 to rotate, so that the lead screw 15 rotates, the slide block 4 moves outwards, and the first insert 7 is stripped while the first insert 7 is stripped by the first core 8 and the first insert 7. After transverse thread stripping is completed, the driving element drives the second driving gear 9 to rotate, the second driving gear 9 drives the second driving shaft 17 and the fifth driven gear 19 to rotate, the fifth driven gear 19 drives the sixth driven gear 20 to rotate, so that the driven shaft 18 and the seventh driven gear 21 rotate, finally the second driven gear 10 rotates, the second driven gear 10 rotates to drive the second insert 11 to rotate, the second insert 11 rotates to enable the workpiece 30 and the second insert 11 to move relatively, and the vertical position of the second insert 11 is unchanged, so that the workpiece 30 is slowly stripped upwards in the rotating process of the second insert 11 until the workpiece 30 is separated from the second insert 11, automatic thread stripping of the workpiece 30 is realized, and then the workpiece 30 is ejected through the ejector rod.

The specific embodiments described herein are merely illustrative of the spirit of the invention. Various modifications or additions may be made to the described embodiments or alternatives may be employed by those skilled in the art without departing from the spirit or ambit of the invention as defined in the appended claims.

Although terms of the upper die 1, the lower die 2, the molding cavity 3, the slider 4, the first driving gear 5, the first driven gear 6, the first insert 7, the first core 8, the second driving gear 9, the second driven gear 10, the second insert 11, the second core 12, the first driving shaft 13, the third driven gear 14, the lead screw 15, the fourth driven gear 16, the second driving shaft 17, the driven shaft 18, the fifth driven gear 19, the sixth driven gear 20, the seventh driven gear 21, the molding portion 22, the positioning portion 23, the positioning groove 24, the positioning projection 25, the first bearing 26, the second bearing 27, the third bearing 28, the fourth bearing 29, the workpiece 30, and the like are used more herein, the possibility of using other terms is not excluded. These terms are used merely to more conveniently describe and explain the nature of the present invention; they are to be construed as being without limitation to any additional limitations that may be imposed by the spirit of the present invention.

Claims

1. An automatic thread demoulding die comprises an upper die (1) and a lower die (2), wherein a plurality of forming cavities (3) are formed between the upper die (1) and the lower die (2) after die assembly is carried out, a sliding block (4) capable of translating is arranged on the lower die (2), and the automatic thread demoulding die is characterized in that a first driving gear (5), a plurality of first driven gears (6) and a plurality of first inserts (7) are arranged in the sliding block (4) in an axial positioning mode, the first driven gears (6) are sleeved outside the corresponding first inserts (7), the first driving gear (5) can drive the first inserts (7) to rotate through the first driven gears (6), a first core (8) is axially positioned in the first inserts (7), the inner end of the first core (8) is convexly arranged outside the first inserts (7), and the inner ends of the first inserts (7) and the first core (8) can extend into the corresponding forming cavities (3), the lower die (2) is internally provided with a second driving gear (9), a plurality of second driven gears (10) and a plurality of second inserts (11) which are axially positioned, the second driven gears (10) are sleeved outside the corresponding second inserts (11), the second driving gear (9) can drive the second inserts (11) to rotate through the second driven gears (10), second cores (12) are axially positioned in the second inserts (11), the inner ends of the second cores (12) are convexly arranged outside the second inserts (11), the inner ends of the second inserts (11) and the inner ends of the second cores (12) can extend into the corresponding forming cavities (3), the first inserts (7) and the first cores (8) are arranged along the horizontal direction, the second inserts (11) and the second cores (12) are arranged along the vertical direction, and the first inserts (7) and the second inserts (11) are arranged, The first core (8), the second insert (11) and the second core (12) are arranged in a one-to-one correspondence mode, and the inner end of the first core (8) is matched with the inner end of the second core (12).

2. The automatic thread stripping die according to claim 1, wherein a first driving shaft (13) used for being connected with a driving piece penetrates through the sliding block (4), the first driving gear (5) is sleeved outside the first driving shaft (13), at least one third driven gear (14) is further arranged in the sliding block (4), a lead screw (15) penetrates through the third driven gear (14), the lead screw (15) is connected with the sliding block (4), and the first driving shaft (13) can drive the sliding block (4) to translate through the first driving gear (5), the third driven gear (14) and the lead screw (15).

3. The automatic thread stripping die according to claim 2, wherein at least one fourth driven gear (16) is arranged in the sliding block (4), the fourth driven gear (16) is respectively connected with the corresponding first driven gear (6) and the corresponding third driven gear (14), and the first driving shaft (13) can rotate to drive the sliding block (4) to translate through the first driving gear (5), the first driven gear (6), the fourth driven gear (16), the third driven gear (14) and the screw rod (15).

4. The automatic thread demoulding mould as claimed in claim 1, 2 or 3, wherein a second driving shaft (17) and a plurality of driven shafts (18) penetrate through the lower mould (2), the second driving gear (9) is sleeved at the outer end of the second driving shaft (17), a fifth driven gear (19) is sleeved at the inner end of the second driving shaft (17), a sixth driven gear (20) and a seventh driven gear (21) are respectively sleeved at two ends of the driven shaft (18), and the second driving gear (9) can drive the second insert (11) to rotate through the second driving shaft (17), the fifth driven gear (19), the sixth driven gear (20), the driven shaft (18), the seventh driven gear (21) and the second driven gear (10).

5. The automatic thread stripping die according to claim 1, 2 or 3, wherein each of the first core (8) and the second core (12) comprises a forming portion (22) and a rod-shaped positioning portion (23), the inner end of the positioning portion (23) is fixedly connected with the forming portion (22), the outer end of the positioning portion (23) is fixedly connected with a fastener, the forming portion (22) of the first core (8) is convexly arranged outside the first insert (7), the forming portion (22) of the second core (12) is convexly arranged outside the second insert (11), and the inner ends of the first insert (7) and the second insert (11) can respectively abut against the corresponding forming portion (22) by rotating the fastener.

6. An automatic unscrewing mould as claimed in claim 5, characterized in that the inner face of the profile (22) of the first core (8) has positioning recesses (24) arranged in a recessed manner, and the inner face of the profile (22) of the second core (12) has positioning projections (25) arranged in a protruding manner, said positioning projections (25) being able to engage in corresponding positioning recesses (24).

7. The automatic thread stripping die as claimed in claim 1, 2 or 3, wherein the first driven gear (6) is fixedly sleeved at the end part of the outer end of the first insert (7), the outer side wall of the inner end of the first insert (7) is conical, the second driven gear (10) is fixedly sleeved at the end part of the outer end of the second insert (11), and the outer side wall of the inner end of the second insert (11) is conical.

8. An automatic unscrewing die as claimed in claim 1, 2 or 3, characterized in that a first bearing (26) is provided between each first insert (7) and the slide (4), the first insert (7) being axially positioned with respect to the slide (4) by means of the first bearing (26).

9. An automatic thread stripping die as claimed in claim 1, 2 or 3, characterized in that a second bearing (27) is provided between each second insert (11) and the lower die (2), the second insert (11) being axially positioned with respect to the lower die (2) by means of the second bearing (27).

10. An automatic unscrewing die as claimed in claim 1, 2 or 3, characterized in that a third bearing (28) is provided between the first insert (7) and the first core (8), said third bearing (28) being located at the end of the inner end of the first insert (7), and a fourth bearing (29) is provided between the second insert (11) and the second core (12), said fourth bearing (29) being located at the end of the inner end of the second insert (11).