CN209869444U - Nylon zipper tooth forming device - Google Patents

Abstract

The utility model discloses a nylon zip fastener sprocket shaper, include: two forming screw rods arranged in parallel in the nylon zipper forming machine; a mandrel disposed in parallel between the two forming screws; a sprocket engaging head forming part for vertically clamping the mandrel; and a driving mechanism for driving the forming screw and the sprocket meshing head forming part to move; the sprocket meshing head forming part comprises a stamping part arranged at the top end of the mandrel; a sprocket engaging head forming hammer arranged at the bottom end of the mandrel and opposite to the stamping part; and a stamping part fixed mould arranged on the top end face of the stamping part; therefore, the stamping part can not shake due to the rotation motion of the two forming screw rods through the stamping part fixing die, the structure is stable, the possibility of shaking is avoided, the operation and the correction are easy, the quality of zipper teeth is more stable, and the sliding property of the zipper puller and the meshing strength of the zipper are improved.

Description

Nylon zipper tooth forming device

Technical Field

The utility model relates to a nylon zipper manufacturing technical field indicates a be applied to nylon zipper teeth forming device of nylon zipper make-up machine especially.

Background

For a conventional nylon slide fastener molding machine, the following patent documents are referred to.

For example, chinese patent application No. CN109008090A entitled fastener element row forming apparatus, and chinese patent application No. CN1168406C entitled method and apparatus for manufacturing continuous fastener element rows of slide fastener.

It can be known from the prior art that in the process of forming and manufacturing the teeth of the nylon zipper, the nylon thread is fed into a forming module for processing, a pair of forming screws and a mandrel are arranged in the forming module, the nylon thread is fed from the lower end of the mandrel and spirally winds around the mandrel upwards, the forming screws are driven to rotate to guide the upward nylon thread, so that the nylon thread is manufactured into the required size and shape of the teeth according to the specification of the forming screws, and then the nylon thread is sent out of the forming module.

However, in the fastener element row forming apparatuses described in the above-mentioned two patent documents, how the forming screw and the coupling head forming hammer are driven is not described in detail, and how the forming screw and the coupling head forming hammer are operated after the element monofilament is wound around the mandrel is not further described.

In addition, since any structure for supporting or fixing is not described in detail in the related art, the die structure is likely to be shaken due to the rotational movement of the molding screw during the molding of the monofilament, and the shape of the formed fastener element is deviated, thereby deteriorating the slidability of the slider of the slide fastener and the coupling strength of the slide fastener.

Disclosure of Invention

To the defect that exists among the prior art, the utility model aims to provide a can reduce the shape production deviation after the sprocket forms, improve the sliding property of zip fastener pull head and the nylon zip fastener sprocket forming device of the meshing intensity of zip fastener.

In order to achieve the above purpose, the utility model adopts the following technical scheme.

A nylon slide fastener element forming apparatus comprising: two forming screw rods (1, 1') which are arranged in parallel in the nylon zipper forming machine (10) and the front ends of which are exposed out of the nylon zipper forming machine (10); a mandrel (2) parallel to said two forming screws (1, 1 ') and extending between said opposite forming screws (1, 1'); a sprocket engaging head forming part (3) provided between the two molding screws (1, 1') and sandwiching the mandrel (2) from above and below; and a driving mechanism (4) arranged at the bottom end of the nylon zipper forming machine (10) and used for driving the forming screw rods (1, 1') and the zipper tooth meshing head forming part (3) to move; the method is characterized in that: the sprocket engaging head forming part (3) comprises a stamping part (31) arranged at the top end of the mandrel (2); a sprocket engaging head forming hammer (32) disposed at the bottom end of the mandrel (2) and disposed opposite to the stamping part (31); and a stamping piece fixed die (33) arranged on the top end face of the stamping piece (31); the stamping part fixed die (33) consists of a module (331) which is locked on the top end surface of the nylon zipper forming machine (10) and is provided with a lock hole (3311) corresponding to the stamping part (31), and a bolt (332) which penetrates through the lock hole (3311) and is propped against the top end of the stamping part (31); the driving mechanism (4) comprises a first driving part (41), a second driving part (42), a third driving part (43), a fourth driving part (44) and a fifth driving part (45), and the driving parts (41, 42, 43, 44 and 45) are meshed with each other to form synchronous transmission of power, so that the two forming screws (1 and 1') and the sprocket meshing head forming hammer (32) are driven to rotate relatively.

More preferably, the first driving member (41) is composed of a first gear shaft (411) arranged in parallel with the two forming screws (1, 1'); a pulley (412) locked at the front end of the first gear shaft (411) for driving the first gear shaft (411) to rotate; a first bevel gear (413) disposed at a rear end of the first gear shaft (411); and a first guide wheel (414) disposed between the first bevel gear (413) and the pulley (412).

More preferably, the center of the belt pulley (412) is further provided with a sleeve hole (4121) for the belt pulley (412) to be sleeved on the first gear shaft (411), the sleeve hole (4121) is further internally provided with two tapered tightening rings (5) and a tightening shaft sleeve (6), and the two tapered tightening rings (5) are matched with the tightening shaft sleeve (6) to be locked and combined with the first gear shaft (411) so as to fix the belt pulley (412) and the first gear shaft (411).

More preferably, the second driving member (42) is composed of a second gear shaft (421) which is arranged in parallel with the two forming screws (1, 1'); and a second guide wheel (422) which is concentric with the second gear shaft (421), is engaged with the first guide wheel (414) and the two forming screws (1, 1 '), and can be driven by the first guide wheel (414) to rotate so as to drive the two forming screws (1, 1') to rotate.

More preferably, the third driving member (43) is composed of a third gear shaft (431) which is vertically arranged with the two molding screws (1, 1'); a third guide wheel (432) disposed at one end of the third gear shaft (431); and a second bevel gear (433) which is concentric with the third gear shaft (431), meshed with the first bevel gear (413) and can be driven to rotate by the first bevel gear (413) so as to drive the third guide wheel (432) to rotate.

More preferably, the fourth driving member (44) is formed by a fourth gear shaft (441) which is perpendicular to the two molding screws (1, 1'); and a fourth guide wheel (442) which is arranged at one end of the fourth gear shaft (441) and meshed with the third guide wheel (432) and can be driven by the third guide wheel (432) to rotate.

More preferably, the fifth driving member (45) is formed by a fifth gear shaft (451) which is perpendicular to the two molding screws (1, 1'); a pressing roller (321) disposed at one end of the fifth gear shaft (451); and a fifth guide wheel (452) which is arranged at one end of the fifth gear shaft (451), is meshed with the fourth guide wheel (442), and can be driven by the fourth guide wheel (442) to rotate so as to drive the sprocket meshing head forming hammer (32) to rotate.

More preferably, the sprocket engaging head forming hammer (32) is formed by a fifth gear shaft (451) arranged perpendicularly to the spindle (2); and a press roller (321) which is positioned at the bottom end of the mandrel (2) and is concentric with the fifth gear shaft (451) and takes the shape of a circular plate.

More preferably, the nylon zipper forming machine (10) comprises a die holder (101); a front mold body (102) arranged at the front end of the top end surface of the mold base (101); a rear mold body (103) arranged at the rear end of the top end surface of the mold base (101); a strip groove (104) which is arranged on the top end surface of the front mold body (102) and is parallel to the molding screws (1, 1'); a circular groove (105) which is arranged on the top end surface of the front mold body (102) and is overlapped and communicated with the strip groove (104); and a through hole (106) penetrating the circular groove (105).

More preferably, said stamping (31) is constituted by a shaped bar (311) having a stage (3111) and inserted in the through hole (106); a forming end (312) which is arranged at the front end of the forming rod piece (311) and has a rectangular cross section; a first disc spring (313) concentrically arranged with the shaped bar (311); and a lock cover (314) embedded in the long groove (104) and the circular groove (105) and connected with the top end of the molding rod piece (311); a second disc spring (7) corresponding to the first disc spring (313) is also arranged in the circular groove (105).

According to the technical means, the utility model discloses following function and effect have:

a slide fastener slider is provided with a pressing member fixing die (33) which prevents a pressing member (31) from wobbling due to rotational movement of two molding screws (1, 1'), is stable in structure without wobbling, is easy to operate and correct, and improves the quality of a fastener element, the slidability of the slider, and the engagement strength of a slide fastener.

And secondly, the two forming screw rods (1, 1') and the sprocket meshing head forming hammer (32) can be driven to simultaneously act through the application of the driving mechanism (4), so that the effect of reducing power loss through single driving is achieved, and the fault removal and maintenance are convenient.

Thirdly, the bolt (332) on the stamping piece fixed die (33) can finely adjust the forming rod piece (311) at any time, the extending amount of the forming end (312) is easily controlled, and the zipper teeth are provided with connecting parts and connecting heads, so the connecting parts of the zipper teeth can be butted against the zipper teeth meshing head forming hammer (32) through the action of continuous pressing after the forming rod piece (311) is finely adjusted, and the zipper teeth are butted and formed into a flat connecting part by the zipper teeth meshing head forming hammer (32), so that the overall appearance of the zipper teeth can approach to a rectangle.

Drawings

Fig. 1 shows a schematic view of the engagement of the sprocket engaging head forming portion with the spindle.

Fig. 2 is a schematic perspective view showing the engagement between the sprocket forming device and the nylon slide fastener forming machine.

Fig. 3 is a schematic cross-sectional view of a sprocket forming apparatus according to the present invention.

Fig. 4 is an exploded view of a punch and a punch holder.

Fig. 5 is a perspective view of the drive mechanism.

FIG. 6 is a schematic cross-sectional view of a pulley.

Description of reference numerals:

1. 1' Forming screw 422 second guide wheel

2 spindle 43 third drive

Third gear shaft of 3-sprocket meshing head forming part 431

31 stamping 432 third guide wheel

311 Molding rod 433 second bevel Gear

3111 stage 44 fourth drive

312 formed end 441 fourth gear shaft

313 first disk spring 442 fourth guide wheel

314 locking cover 45 fifth driving member

32 sprocket engaging head forming hammer 451 fifth gear shaft

321 press roller 452 fifth guide wheel

Tapered packing ring of 33 stamping fixed mould 5

331 module 6 packing shaft sleeve

3311 keyhole 7 second disk spring

332 bolt 10 nylon zipper forming machine

4 driving mechanism 101 die holder

41 first drive member 102 front housing

411 first gear shaft 103 rear mold body

412 pulley 104 elongated groove

4121 round groove of coupling hole 105

413 first bevel gear 106

414 first guide wheel A connection part

42 second driving member B connector

421 second gear shaft

Detailed Description

In the description of the present invention, it should be noted that, for the orientation words, if there are terms such as "center", "lateral", "longitudinal", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc., the orientation and positional relationship indicated are based on the orientation or positional relationship shown in the drawings, and only for the convenience of describing the present invention and simplifying the description, it is not intended to indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and not be construed as limiting the specific scope of the present invention.

Furthermore, if the terms "first" and "second" are used for descriptive purposes only, they are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features. Thus, the definition of "a first" or "a second" feature may explicitly or implicitly include one or more of the features, and in the description of the invention, "at least" means one or more unless specifically defined otherwise.

In the present invention, unless otherwise expressly specified or limited, the terms "assembled", "connected", and "connected", if any, are to be construed broadly, e.g., as meaning fixedly connected, detachably connected, or integrally connected; or may be a mechanical connection; the two elements can be directly connected or connected through an intermediate medium, and the two elements can be communicated with each other. The specific meaning of the above terms in the present invention can be understood by those of ordinary skill in the art according to specific situations.

In the present application, unless otherwise specified or limited, "above" or "below" a first feature may include the first and second features being in direct contact, and may also include the first and second features not being in direct contact but being in contact with each other through another feature therebetween. Also, the first feature being "above," "below," and "above" the second feature includes the first feature being directly above and obliquely above the second feature, or simply an elevation which indicates a level of the first feature being higher than an elevation of the second feature. The first feature being "above", "below" and "beneath" the second feature includes the first feature being directly below or obliquely below the second feature, or merely means that the first feature is at a lower level than the second feature.

The following description will be further made in conjunction with the accompanying drawings of the specification, so that the technical solution and the advantages of the present invention are clearer and clearer. The embodiments described below are exemplary and are intended to be illustrative of the present invention, but should not be construed as limiting the invention.

As shown in fig. 1 and 5, a nylon zipper teeth forming device comprises: two forming screw rods 1, 1' which are arranged in parallel in the nylon zipper forming machine and the front ends of which are exposed out of the nylon zipper forming machine; a mandrel 2 parallel to said two forming screws 1, 1 'and extending between said opposite forming screws 1, 1'; a sprocket engaging head forming part 3 provided between the two molding screws 1, 1' and sandwiching the mandrel 2 from above and below; and a driving mechanism 4 arranged at the bottom end of the nylon zipper forming machine and used for driving the forming screw rods 1 and 1' and the zipper teeth meshing head forming part 3 to move.

As shown in fig. 2, the nylon zipper forming machine 10 includes a mold base 101; a front mold body 102 disposed at the front end of the top surface of the mold base 101; a rear mold body 103 disposed at the rear end of the top end surface of the mold base 101; a strip groove 104 arranged on the top end face of the front mold body 102 and parallel to the molding screws 1, 1'; a circular groove 105 disposed on the top surface of the front mold body 102 and overlapping and communicating with the elongated groove 104; and a through hole 106 penetrating the circular groove 105.

As shown in fig. 3, the sprocket engaging head forming part 3 includes a stamping part 31 disposed at the top end of the mandrel 2, a sprocket engaging head forming hammer 32 disposed at the bottom end of the mandrel 2 in an opposing arrangement to the stamping part 31, and a stamping part fixing die 33 disposed at the top end face of the stamping part 31; the fixed mold 33 is composed of a mold 331 fixed to the top end face of the nylon zipper forming machine 10 and having a lock hole 3311 corresponding to the stamping 31, and a bolt 332 penetrating the lock hole 3311 and abutting against the top end of the stamping 31.

The arrangement of the pressing member fixing die 33 prevents the pressing member 31 from shaking due to the rotational movement of the two molding screws 1, 1', and is stable in structure without shaking, easy to operate and correct, and capable of stabilizing the quality of the fastener element and improving the slidability of the slider of the slide fastener and the engagement strength of the slide fastener.

Referring to fig. 3 and 4, the stamping part 31 is composed of a molding rod 311 having a stage 3111 and inserted into the through hole 106, a molding end 312 with a rectangular cross section disposed at the front end of the molding rod 311, a first disk spring 313 concentrically disposed with the molding rod 311, and a locking cap 314 inserted into the elongated recess 104 and the circular recess 105 and connected to the top end of the molding rod 311; the circular groove 105 is further provided with a second disc spring 7 corresponding to the first disc spring 313, and the sprocket-engaging head forming hammer 32 is composed of a fifth gear shaft 451 provided perpendicularly to the spindle 2 and a pressing roller 321 provided at the bottom end of the spindle 2 and concentrically provided with the fifth gear shaft 451 in a circular plate shape.

As shown in fig. 3, the stamping part 31 and the forming hammer 32 of the sprocket engaging head can clamp and fix the monofilament of the sprocket onto the mandrel 2, and then the bolt 332 on the fixed die 33 of the stamping part can finely adjust the forming rod 311 at any time, so as to easily control the extending amount of the forming end 312, because the sprocket has the connecting part a and the connecting head B, the connecting part a of the sprocket can be abutted against the forming hammer 32 of the sprocket engaging head by the continuous pressing action after the fine adjustment of the forming rod 311, and the forming hammer 32 of the sprocket engaging head can be pressed and formed into a flat connecting part a, so that the overall appearance of the sprocket can approach to a rectangle, and in use, the matching degree of the zipper head and the sprocket can be more compact, so as to greatly improve the quality of the sprocket.

Referring to fig. 5, the driving mechanism 4 includes a first driving member 41, a second driving member 42, a third driving member 43, a fourth driving member 44 and a fifth driving member 45, and is configured as follows:

the first driving member 41 is composed of a first gear shaft 411 disposed in parallel with the two forming screws 1, 1', a belt pulley 412 locked at the front end of the first gear shaft 411 for driving the first gear shaft 411 to rotate, a first bevel gear 413 disposed at the rear end of the first gear shaft 411, and a first guiding wheel 414 disposed between the first bevel gear 413 and the belt pulley 412.

The second driving member 42 is composed of a second gear shaft 421 disposed in parallel with the two molding screws 1, 1 ', and a second guiding wheel 422 disposed concentrically with the second gear shaft 421, engaged with the first guiding wheel 414 and the two molding screws 1, 1 ', and driven by the first guiding wheel 414 to rotate so as to drive the two molding screws 1, 1 ' to rotate.

The third driving member 43 is composed of a third gear shaft 431 perpendicular to the two molding screws 1, 1', a third guiding wheel 432 disposed at one end of the third gear shaft 431, and a second bevel gear 433 disposed concentrically with the third gear shaft 431, engaged with the first bevel gear 413, and driven by the first bevel gear 413 to rotate so as to drive the third guiding wheel 432 to rotate.

The fourth driving member 44 is composed of a fourth gear shaft 441 perpendicular to the two molding screws 1 and 1', and a fourth guide wheel 442 disposed at one end of the fourth gear shaft 441 and meshed with the third guide wheel 432, and driven by the third guide wheel 432 to rotate.

The fifth driving member 45 is composed of a fifth gear shaft 451 perpendicular to the two forming screws 1, 1', a pressing roller 321 disposed at one end of the fifth gear shaft 451, and a fifth guide wheel 452 disposed at one end of the fifth gear shaft 451, engaged with the fourth guide wheel 442, and driven by the fourth guide wheel 442 to rotate so as to drive the sprocket meshing head forming hammer 32 to rotate.

As can be seen from the above, the driving members 41, 42, 43, 44, 45 are engaged with each other to form a synchronous transmission of power, so as to drive the two forming screws 1, 1' and the sprocket engaging head forming hammer 32 to rotate relatively, and thus, the driving members 41, 42, 43, 44, 45 can be driven to operate only by rotating the pulley 412, so that the effect of reducing power loss by a single driving can be achieved, and the troubleshooting and maintenance are convenient.

As shown in fig. 6, the center of the belt pulley 412 is further provided with a sleeve hole 4121 for the belt pulley 412 to be sleeved on the first gear shaft 411, the sleeve hole 4121 is further provided with two tapered tightening rings 5 and a tightening shaft sleeve 6, and the two tapered tightening rings 5 are matched with the tightening shaft sleeve 6 to be locked and combined with the first gear shaft 411, so as to fix the belt pulley 412 and the first gear shaft 411.

The first gear shaft 411 penetrates the sleeve hole 4121, the tapered packing ring 5 is sleeved on the first gear shaft 411 and located in the sleeve hole 4121, when the packing shaft sleeve 6 pushes the tapered packing ring 5 into the sleeve hole 4121 and is locked with the belt pulley 412, the tapered packing ring 5 tightly presses against the belt pulley 412 and the first gear shaft 411, so that the belt pulley 412 can drive the first gear shaft 411 to rotate through the tapered packing ring 5.

Through the arrangement of the two conical tightening rings 5 and the tightening shaft sleeve 6, the first gear shaft 411 can generate smaller deflection and rotate smoothly.

Through the above description of the structure and principles, those skilled in the art should understand that the above description is only for the preferred embodiments of the present invention, and the present invention is not limited to the above embodiments, and all modifications and substitutions based on the conventional techniques in the art fall within the protection scope of the present invention, which should be defined by the claims and their equivalents. The details not described in the detailed description are prior art or common general knowledge.

Claims (10)

1. A nylon zipper tooth forming device comprising:

two forming screw rods (1, 1') which are arranged in parallel in the nylon zipper forming machine (10) and the front ends of which are exposed out of the nylon zipper forming machine (10);

a mandrel (2) parallel to and extending between the two forming screws (1, 1');

a sprocket engaging head forming part (3) which is provided between the two molding screws (1, 1') and which holds the mandrel (2) from above and below; and

a driving mechanism (4) arranged at the bottom end of the nylon zipper forming machine (10) and used for driving the two forming screw rods (1, 1') and the zipper tooth meshing head forming part (3) to act;

the method is characterized in that:

the sprocket engaging head forming part (3) comprises a stamping part (31) arranged at the top end of the mandrel (2), a sprocket engaging head forming hammer (32) arranged at the bottom end of the mandrel (2) and opposite to the stamping part (31), and a stamping part fixed die (33) arranged on the top end surface of the stamping part (31);

the stamping part fixed die (33) consists of a module (331) which is locked on the top end surface of the nylon zipper forming machine (10) and is provided with a lock hole (3311) corresponding to the stamping part (31), and a bolt (332) which penetrates through the lock hole (3311) and is propped against the top end of the stamping part (31);

the driving mechanism (4) comprises a first driving piece (41), a second driving piece (42), a third driving piece (43), a fourth driving piece (44) and a fifth driving piece (45), and the driving pieces (41, 42, 43, 44 and 45) are meshed with each other to form synchronous transmission of power, so that the two forming screws (1 and 1') and the sprocket meshing head forming hammer (32) are driven to rotate relatively.

2. The nylon fastener stringer forming apparatus of claim 1, wherein the first driving member (41) is composed of a first gear shaft (411) disposed in parallel with the two forming screws (1, 1'), a pulley (412) locked to a front end of the first gear shaft (411) for driving the first gear shaft (411) to rotate, a first bevel gear (413) disposed at a rear end of the first gear shaft (411), and a first guide wheel (414) disposed between the first bevel gear (413) and the pulley (412).

3. The nylon zipper teeth forming device of claim 2, wherein the center of the belt pulley (412) is further provided with a sleeve hole (4121) for the belt pulley (412) to be sleeved on the first gear shaft (411), the sleeve hole (4121) is further provided with two tapered tightening rings (5) and a tightening sleeve (6), and the two tapered tightening rings (5) are matched with the tightening sleeve (6) to be locked and combined with the first gear shaft (411) for fixing the belt pulley (412) and the first gear shaft (411).

4. The nylon fastener stringer forming device according to claim 2, wherein the second driving member (42) is composed of a second gear shaft (421) disposed in parallel with the two forming screws (1, 1 '), and a second guide wheel (422) disposed concentrically with the second gear shaft (421), engaged with the first guide wheel (414) and the two forming screws (1, 1 '), and driven by the first guide wheel (414) to rotate so as to drive the two forming screws (1, 1 ') to rotate.

5. The nylon fastener stringer forming apparatus of claim 4, wherein the third driving member (43) is composed of a third gear shaft (431) vertically disposed with the two forming screws (1, 1'), a third guide wheel (432) disposed at one end of the third gear shaft (431), and a second bevel gear (433) concentrically disposed with the third gear shaft (431) and engaged with the first bevel gear (413), and driven to rotate by the first bevel gear (413) to rotate the third guide wheel (432).

6. The nylon fastener stringer forming apparatus of claim 5, wherein the fourth driving member (44) is composed of a fourth gear shaft (441) perpendicularly installed to the two molding screws (1, 1'), and a fourth guide wheel (442) installed at one end of the fourth gear shaft (441) to be engaged with the third guide wheel (432) and driven to rotate by the third guide wheel (432).

7. The nylon fastener stringer forming apparatus of claim 6, wherein the fifth driving member (45) is composed of a fifth gear shaft (451) perpendicular to the two forming screws (1, 1'), a pressing roller (321) disposed at one end of the fifth gear shaft (451), and a fifth guide wheel (452) disposed at one end of the fifth gear shaft (451) and engaged with the fourth guide wheel (442), and driven to rotate by the fourth guide wheel (442) to rotate the fastener engaging head forming hammer (32).

8. The nylon fastener element forming device according to claim 1 or 7, wherein the element engaging head forming hammer (32) is composed of a fifth gear shaft (451) arranged perpendicularly to the mandrel (2), and a pressing roller (321) disposed at a lower end of the mandrel (2) and arranged concentrically with the fifth gear shaft (451) in a circular plate shape.

9. The device for forming nylon fastener stringers as claimed in claim 1, wherein said nylon fastener forming machine (10) comprises a die holder (101), a front body (102) provided on a front end of a top surface of said die holder (101), a rear body (103) provided on a rear end of a top surface of said die holder (101), an elongated groove (104) provided on a top surface of said front body (102) and arranged in parallel with said two forming screws (1, 1'), a circular groove (105) provided on a top surface of said front body (102) and overlapped with and communicated with said elongated groove (104), and a through hole (106) penetrating said circular groove (105).

10. The nylon fastener element forming apparatus according to claim 9, wherein the pressing member (31) is composed of a molding bar (311) having a stepped section (3111) and inserted into the through hole (106), a molding end (312) of a rectangular cross section provided at a front end of the molding bar (311), a first disc spring (313) concentrically provided with the molding bar (311), and a locking cap (314) inserted into the elongated recess (104) and the circular recess (105) and connected to a top end of the molding bar (311); and a second disc spring (7) corresponding to the first disc spring (313) is also arranged in the circular groove (105).