CN217036094U - TYPE C plug connector - Google Patents

Abstract

The utility model discloses a TYPE C plug connector which at least comprises a rubber core main body, an upper row of terminals, a lower row of terminals and a shell, wherein the upper row of terminals and the lower row of terminals are arranged in the rubber core main body, the shell is fixedly wrapped on the outer surface of the rubber core main body, the front end of the rubber core main body is provided with an opposite slot, a first guide connection part of the upper row of terminals and a second guide connection part of the lower row of terminals are arranged in the opposite slot, the head part of the upper row of terminals is bent to form a first boss protruding upwards, and the upper end of the first boss is contacted with the upper inner wall of the opposite slot so as to form downward pre-pressure on the first guide connection part; the head part of the lower row of terminals is bent to form a second boss protruding downwards, and the lower end of the second boss is in contact with the lower inner wall of the slot so as to form an upward pre-pressure on the second guide connection part; the upper and lower row of terminal respectively through first, second boss with to the upper and lower inner wall contact of slot to improve first, the high roughness of second lead connection portion bullet, solved height PIN's problem, and can effectively reduce the contact stress when first, the contact of second lead connection portion, can increase substantially life.

Description

TYPE C plug connector

The technical field is as follows:

the utility model relates to the technical field of connectors, in particular to a TYPE C plug connector.

Background art:

USB is an abbreviation for Universal Serial BUS, and is referred to as "Universal Serial BUS" for short, and is an external BUS standard for standardizing the connection and communication between a computer and external devices, and is an interface technology applied in the PC field. USB was proposed by a combination of companies such as Intel, Conjun, IBM, Microsoft, etc., at the end of 1994. The USB has high transmission speed and is very convenient to use. The USB interface also has the advantages of supporting the plug-and-play and hot plug functions of the equipment, being flexible in connection, independent power supply and the like, can be connected with a mouse, a keyboard, a printer, a scanner, a camera, a flash disk, an MP3 machine, a mobile phone, a digital camera, a mobile hard disk, an external optical floppy drive, a USB network card, an ADSL Modem, a Cable Modem and the like, almost all external equipment is provided with the USB interface, and the USB interface is very widely used.

TYPE C is a connection interface of USB interface, can be inserted without dividing the front and back sides, the size is about 8.3mm x 2.5mm, and it supports the functions of charging, data transmission, display output, etc. of USB standard as other interfaces. TYPE C connectors are mainly oriented to thinner, slimmer devices, enhancing usability and making a way for performance enhancement of future USB versions.

Conventional TYPE C plug connector leads to can't set up the dog at the plastic wall and carries out the pre-compaction to the contact site of the head of upper and lower row of terminal because it is thinner to the plastic wall in the slot, makes the high height PIN of upper and lower row of end bullet serious, and upper and lower row of terminal resilience ability is not enough, and life is lower, leads to its market competition not enough.

In view of this, the present inventors propose the following.

The utility model has the following contents:

the utility model aims to overcome the defects in the prior art and provides a TYPE C plug connector.

In order to solve the technical problems, the utility model adopts the following technical scheme: the TYPE C plug connector at least comprises a rubber core main body, an upper row of terminals and a lower row of terminals which are arranged in the rubber core main body, and a shell fixedly coated on the outer surface of the rubber core main body, wherein the front end of the rubber core main body is provided with an opposite slot, a first guide connection part which is formed by the head parts of the upper row of terminals and protrudes downwards and a second guide connection part which is formed by the head parts of the lower row of terminals and protrudes upwards are both arranged in the opposite slot, the head parts of the upper row of terminals are also bent to form a first boss which protrudes upwards, and the upper end of the first boss is contacted with the upper inner wall of the opposite slot so as to form downward pre-pressure on the first guide connection part; the head of the lower row of terminals is also bent to form a second boss protruding downwards, and the lower end of the second boss is in contact with the lower inner wall of the slot so as to form an upward pre-pressure on the second guide connection part.

Furthermore, in the above technical solution, the upper row of terminals is integrally fixed in the upper insulator, the first bosses and the first connecting portions at the heads of the upper row of terminals extend out of the front end surface of the upper insulator, and the first pins formed by bending the tails of the upper row of terminals extend out of the rear end surface of the upper insulator; the lower row of terminals are integrally fixed in the lower insulator, a second boss and a second guide connection part at the head of the lower row of terminals extend out of the front end surface of the lower insulator, and a second pin formed by bending the tail of the lower row of terminals extends out of the rear end surface of the lower insulator; the upper insulator and the lower insulator are stacked together, and the rubber core main body is fixed outside the upper insulator and the lower insulator.

Furthermore, in the above technical solution, a snap plate is further fixed between the upper insulator and the lower insulator, and a first snap and a second snap formed at the front end of the snap plate extend out of the front ends of the upper insulator and the lower insulator and are respectively disposed on the inner walls of the two sides of the slot.

Furthermore, in the above technical solution, the rubber core main body includes a bottom case and an upper cover, and the bottom case and the upper cover are fastened together.

Furthermore, in the above technical solution, a first EMI elastic sheet is arranged in the upper cover, a plurality of reverse first elastic hooks are formed at the front end of the first EMI elastic sheet by stamping, and the first elastic hooks extend downward out of the lower end surface of the upper cover and are arranged in the opposite slots; the bottom shell is internally provided with a second EMI elastic sheet, the front end of the second EMI elastic sheet is punched to form a plurality of reverse second elastic hooks, and the second elastic hooks extend upwards out of the upper end face of the bottom shell and are arranged in the opposite insertion grooves.

Furthermore, in the above technical scheme, the upper cover is integrated with the first EMI elastic sheet in an in-mold injection molding manner; the bottom shell is fixedly integrated with the second EMI elastic sheet in an in-mold injection molding mode.

Furthermore, in the above technical solution, the first EMI leaf is provided with a plurality of first hole locations, and the upper cover is partially and integrally fixed in the first hole locations; the second EMI elastic sheet is provided with a plurality of second hole sites, and the bottom shell is locally and integrally fixed in the second hole sites.

Further, in the above technical solution, a plurality of first rectangular platforms, first cylinders, first rectangular grooves, and first cylindrical grooves are formed on the lower end surface of the upper insulator; the upper end face of the lower insulator is provided with a plurality of second rectangular platforms, second cylinders, second rectangular grooves and second cylindrical grooves in a molding mode, the first rectangular platforms and the first cylinders are respectively embedded into the second rectangular grooves and the second cylindrical grooves, and the second rectangular platforms and the second cylinders are respectively embedded into the first rectangular grooves and the first cylindrical grooves.

Further, in the above technical solution, the upper end surface of the upper insulator is further provided with a first positioning post, and the first positioning post is embedded into a first positioning hole of the rubber core main body; and the lower end face of the lower insulator is also provided with a second positioning column which is embedded into a second positioning hole of the rubber core main body.

Further, in the above technical solution, the back sides of the upper and lower end surfaces of the rubber core main body are formed with reverse buckles, and the reverse buckles are clamped into clamping holes formed at the back end of the housing; the edge of the opening at the front end of the shell is formed with a flange which is folded from outside to inside, and the flange is blocked at the periphery of the front end of the rubber core main body.

After adopting the technical scheme, compared with the prior art, the utility model has the following beneficial effects: the head parts of the upper row of terminals are also bent to form first bosses protruding upwards, the upper ends of the first bosses are contacted with the upper inner wall of the opposite slots, so that downward pre-pressure is formed on the first guide connection parts, the elastic heights of the first guide connection parts in all the upper row of terminals are equal, the elastic height flatness is improved, and the first bosses are distributed in the opposite slots in a straight line shape side by side, so that the problem of high and low PIN (personal identification number) is solved, the resilience capability of the first guide connection parts is ensured, the contact stress of the first guide connection parts during contact can be effectively reduced, and the service life can be greatly prolonged; the head of the lower row of terminals is bent to form a second boss protruding downwards, the lower end of the second boss is in contact with the lower inner wall of the slot, upward pre-pressure is formed on the second guide connection part, so that the spring heights of the second guide connection parts in all the lower row of terminals are equal, the spring height flatness is improved, the spring heights are distributed in the slot in a linear mode, the problem of high and low PIN is solved, the resilience capability of the second guide connection part is ensured, the contact stress of the second guide connection part during contact can be effectively reduced, and the service life can be greatly prolonged.

Description of the drawings:

FIG. 1 is a perspective view of the present invention;

FIG. 2 is a cross-sectional view of the present invention;

FIG. 3 is an exploded perspective view of the present invention;

FIG. 4 is a perspective view of the present invention with the housing removed;

fig. 5 is an assembly view of the upper row of terminals and the upper insulator of the present invention.

The specific implementation mode is as follows:

in order to make the technical problems solved, the technical solutions adopted and the technical effects achieved by the present invention clearer, the technical solutions of the present invention are further described below by way of specific embodiments with reference to the accompanying drawings. It is to be understood that the specific embodiments described herein are merely illustrative of the utility model and are not to be construed as limiting the utility model. It should be further noted that, for the convenience of description, only some but not all of the elements associated with the present invention are shown in the drawings.

In the description of the present invention, unless expressly stated or limited otherwise, the terms "connected," "connected," and "fixed" are to be construed broadly, e.g., as meaning permanently connected, removably connected, or integral to one another; can be mechanically or electrically connected; they may be directly connected or indirectly connected through intervening media, or may be connected through the use of two elements or the interaction of two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

In the present invention, unless otherwise expressly stated or limited, "above" or "below" a first feature means that the first and second features are in direct contact, or that the first and second features are not in direct contact but are in contact with each other via another feature therebetween. Also, the first feature "on," "above" and "over" the second feature may include the first feature being directly above and obliquely above the second feature, or simply indicating that the first feature is at a higher level than the second feature. "beneath," "under" and "beneath" a first feature includes the first feature being directly beneath and obliquely beneath the second feature, or simply indicating that the first feature is at a lesser elevation than the second feature.

In the description of the present embodiment, the terms "upper", "lower", "right", etc. are used in an orientation or positional relationship based on that shown in the drawings only for convenience of description and simplicity of operation, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first" and "second" are used only for descriptive purposes and are not intended to have a special meaning.

The utility model is further illustrated below with reference to specific embodiments and the accompanying drawings.

As shown in fig. 1-5, the TYPE C plug connector at least includes a rubber core main body 1, an upper row of terminals 2, a lower row of terminals 3, and a housing 4, wherein the housing 4 is fixedly wrapped on the outer surface of the rubber core main body 1; this go up row terminal 2 and arrange terminal 3 down and set up in gluing core main part 1 to this glue core main part 1 front end is equipped with to slot 10, and this upward 2 fashioned downward bellied first lead-out portion 21 of terminal head and the upward bellied second lead-out portion 31 of terminal 3 head down of this row of terminal are all arranged in this to slot 10, and wherein first lead-out portion 21 and second lead-out portion 31 distribute in this slot 10 with the mode of symmetry from top to bottom for to inserting and switch on with TYPE C socket connector.

In order to solve the problems of unequal spring heights and serious high and low PIN (personal identification number) of the first lead-out part 21 of the upper row of terminals 2 and the second lead-out part 31 of the lower row of terminals 3, the utility model makes the following settings: the head of the upper row of terminals 2 is also bent to form a first boss 22 protruding upwards, the upper end of the first boss 22 contacts with the upper inner wall of the slot 10, wherein the upper end of the first boss 22 contacts with the upper inner wall of the slot 10 in an interference fit manner so as to form downward pre-pressure on the first guide connection part 21, so that the spring heights of the first guide connection parts 21 in all the upper row of terminals 2 are equal, the spring height flatness is improved, and the first guide connection parts are distributed in the slot 10 in a straight line shape side by side, the problem of high and low PIN is solved, the resilience of the first guide connection parts 21 is ensured, the contact stress of the first guide connection parts 21 during contact can be effectively reduced, and the service life can be greatly prolonged; the head of the lower row of terminals 3 is further bent to form a second boss 32 protruding downwards, the lower end of the second boss 32 contacts with the lower inner wall of the slot 10, wherein the lower end of the second boss 32 contacts with the lower inner wall of the slot 10 in an interference fit manner, so as to form an upward pre-pressure on the second lead-in part 31, so that the spring heights of the second lead-in parts 31 in all the lower row of terminals 3 are equal, the spring height flatness is improved, and the second lead-in parts are distributed in the slot 10 side by side in a straight line shape, the problem of high and low PINs is solved, the resilience capability of the second lead-in part 31 is ensured, the contact stress when the second lead-in parts 31 contact can be effectively reduced, and the service life can be greatly prolonged.

The upper row terminal 2 is integrally fixed in an upper insulator 5, specifically, the upper insulator 5 is integrally fixed on the periphery of the upper row terminal 2 by means of in-mold injection molding; the first boss 22 and the first guiding part 21 at the head of the upper row of terminals 2 extend out of the front end surface of the upper insulator 5, and the first pin 23 formed by bending the tail of the upper row of terminals 2 extends out of the rear end surface of the upper insulator 5; the lower row of terminals 3 is integrally fixed in the lower insulator 6, specifically, the lower insulator 6 is integrally fixed at the periphery of the lower row of terminals 3 by means of in-mold injection molding, the second boss 32 and the second guiding connection portion 31 at the head of the lower row of terminals 3 both extend out of the front end surface of the lower insulator 6, and the second pin 33 formed by bending the tail of the lower row of terminals 3 extends out of the rear end surface of the lower insulator 6.

The upper insulator 5 and the lower insulator 6 are stacked together, and the rubber core main body 1 is fixed to the outside of the upper insulator 5 and the lower insulator 6. Specifically, a plurality of first rectangular bases 51, first cylindrical bodies 52, first rectangular grooves 53 and first cylindrical grooves 54 are formed on the lower end surface of the upper insulator 5; the upper end face of the lower insulator 6 is formed with a plurality of second rectangular platforms 61, second cylinders 62, second rectangular grooves 63, and second cylindrical grooves 64, the first rectangular platforms 51 and the first cylinders 52 are respectively embedded into the second rectangular grooves 63 and the second cylindrical grooves 64, and the second rectangular platforms 61 and the second cylinders 62 are respectively embedded into the first rectangular grooves 53 and the first cylindrical grooves 54, so as to ensure that the upper insulator 5 and the lower insulator 6 have stable structures after being stacked together, and are convenient to assemble with the rubber core main body 1. Still further, the upper end surface of the upper insulator 5 is further provided with a first positioning column 55, and the first positioning column 55 is embedded into the first positioning hole 101 of the rubber core main body 1; the lower end face of the lower insulator 6 is further provided with a second positioning column 65, and the second positioning column 65 is embedded into the second positioning hole 102 of the rubber core main body 1, so that the upper insulator 5, the lower insulator 6 and the rubber core main body 1 are stably assembled together.

A snap plate 7 is further fixed between the upper insulator 5 and the lower insulator 6, wherein a first circular hole 701 and a second circular hole 702 which are respectively matched with the first cylinder 52 and the second cylinder 62 are arranged on the snap plate 7, and the first circular hole 701 and the second circular hole 702 are respectively sleeved on the peripheries of the first cylinder 52 and the second cylinder 62, so that the snap plate 7 is more stably installed between the upper insulator 5 and the lower insulator 6.

The first buckle 71 and the second buckle 72 formed at the front end of the buckle plate 7 extend out of the front ends of the upper insulator 5 and the lower insulator 6 and are respectively arranged on the inner walls of the two sides of the slot 10, and the upper insulator 5 and the lower insulator 6 are used for clamping and positioning with the two sides of the tongue plate in the TYPE C socket connector after being inserted into the TYPE C socket connector so as to increase the insertion and extraction force, so that after being inserted into the TYPE C socket connector, the upper insulator 5 and the lower insulator 6 are more stable in structure, prevent accidental separation and ensure the stability of electrical conduction.

The rubber core main body 1 is of a two-piece structure, wherein the rubber core main body 1 comprises a bottom shell 11 and an upper cover 12, the bottom shell 11 and the upper cover 12 are mutually fastened and fixed together, a plurality of reverse buckles are arranged on the bottom shell 11, and fastening holes corresponding to the reverse buckles are arranged on the upper cover 12 and fastened and fixed with the fastening holes, so that the bottom shell 11 and the upper cover 12 are fixed together; or, a plurality of reverse buckles are arranged at the lower end of the upper cover 12, the bottom shell 11 is provided with buckling holes corresponding to the reverse buckles, and the reverse buckles are buckled and fixed with the buckling holes, so that the bottom shell 11 and the upper cover 12 are fixed together.

The first EMI elastic sheet 13 is arranged in the upper cover 12, the strength of the upper cover 12 can be enhanced through the first EMI elastic sheet 13, and the EMI anti-interference capability can be improved; the front end of the first EMI elastic piece 13 is stamped to form a plurality of reverse first elastic hooks 131, and the first elastic hooks 131 extend downwards out of the lower end surface of the upper cover 12 and are arranged in the slot 10; the second EMI elastic sheet 14 is arranged in the bottom case 11, and the strength of the bottom case 11 can be enhanced through the second EMI elastic sheet 14, so that the EMI anti-interference capability can be improved; the front end of the second EMI resilient piece 14 is stamped to form a plurality of reverse second resilient hooks 141, and the second resilient hooks 141 extend upward from the upper end surface of the bottom case 11 and are disposed in the slot 10. The first elastic hook 131 and the second elastic hook 141 are both used for participating in insertion and extraction force with a TYPE C socket connector.

The first EMI elastic piece 13 and the second EMI elastic piece 14 are both of an integrated structure, and have stable structures, so that the strength of the first elastic hook 131 and the strength of the second elastic hook 141 are ensured.

The upper cover 12 is fixed with the first EMI elastic sheet 13 into a whole in an in-mold injection molding mode, and the assembly structure is extremely stable; the bottom shell 11 is fixed with the second EMI elastic sheet 14 into a whole in an in-mold injection molding mode, and the assembly structure is extremely stable.

The first EMI elastic piece 13 is provided with a plurality of first hole sites 132, and the upper cover 12 is partially and integrally fixed in the first hole sites 132, so as to further ensure the structural strength of the first EMI elastic piece and the first hole sites 132; the second EMI resilient piece 14 is provided with a plurality of second holes 142, and the bottom case 11 is partially and integrally fixed in the second holes 142, so as to further ensure the structural strength of the two.

The back sides of the upper end face and the lower end face of the rubber core main body 1 are both formed with an inverted buckle 103, and the inverted buckles 103 are clamped in clamping holes 41 formed in the back end of the shell 4; the shaping of shell 4 front end opening edge has flange 42 that outside-in turned over, and this flange 42 keeps off and is being glued core main part 1 front end periphery to this guarantees to glue core main part 1 and stably locates at shell 4, guarantees firm intensity and the structural stability of structure.

In summary, the head of the upper row of terminals 2 is further bent to form a first boss 22 protruding upwards, the upper end of the first boss 22 contacts with the upper inner wall of the slot 10 to form a downward pre-pressure on the first guide connection part 21, so that the spring heights of the first guide connection parts 21 in all the upper row of terminals 2 are equal, the spring height flatness is improved, and the first guide connection parts are distributed in the slot 10 in a linear shape side by side, the PIN height problem is solved, the spring-back capability of the first guide connection parts 21 is ensured, the contact stress when the first guide connection parts 21 contact can be effectively reduced, and the service life can be greatly prolonged; the head of the lower row of terminals 3 is bent to form a second boss 32 protruding downwards, the lower end of the second boss 32 contacts with the lower inner wall of the slot 10 to form an upward pre-pressure on the second guide connection part 31, so that the heights of the second guide connection parts 31 in all the lower row of terminals 3 are equal, the height flatness of the springs is improved, and the springs are distributed in the slot 10 in a straight line shape, so that the problem of high and low PIN is solved, the resilience of the second guide connection parts 31 is ensured, the contact stress when the second guide connection parts 31 contact can be effectively reduced, and the service life can be greatly prolonged.

It should be understood that the above description is only exemplary of the present invention, and is not intended to limit the scope of the present invention, which is defined by the appended claims.

Claims (10)

1. The utility model provides a TYPE C plug connector, it is at least including gluing core main part (1), set up in gluing core main part (1) last row terminal (2) and lower row terminal (3), fixed cladding in shell (4) of gluing core main part (1) surface, should glue core main part (1) front end and be equipped with to slot (10), should go up the fashioned downward bellied first of row terminal (2) head and lead that portion (21) and lower row terminal (3) head fashioned upward bellied second lead that portion (31) all arrange in this pair slot (10), its characterized in that:

the head of the upper row of terminals (2) is also bent to form a first boss (22) protruding upwards, and the upper end of the first boss (22) is in contact with the upper inner wall of the slot (10) so as to form downward pre-pressure on the first guide connection part (21); the head of the lower row of terminals (3) is also bent to form a second boss (32) protruding downwards, and the lower end of the second boss (32) is in contact with the lower inner wall of the slot (10) so as to form upward pre-pressure on the second guide connection part (31).

2. The TYPE C plug connector of claim 1, wherein: the upper row of terminals (2) are integrally fixed in the upper insulator (5), the first bosses (22) and the first guide connecting parts (21) at the head parts of the upper row of terminals (2) extend out of the front end surface of the upper insulator (5), and the first pins (23) formed by bending the tail parts of the upper row of terminals (2) extend out of the rear end surface of the upper insulator (5); the lower row of terminals (3) is integrally fixed in the lower insulator (6), a second boss (32) and a second guide connection part (31) at the head part of the lower row of terminals (3) extend out of the front end surface of the lower insulator (6), and a second pin (33) formed by bending the tail part of the lower row of terminals (3) extends out of the rear end surface of the lower insulator (6); the upper insulator (5) and the lower insulator (6) are stacked together, and the rubber core main body (1) is fixed outside the upper insulator (5) and the lower insulator (6).

3. The TYPE C plug connector of claim 2, wherein: a clamping plate (7) is further fixed between the upper insulator (5) and the lower insulator (6), and a first clamping buckle (71) and a second clamping buckle (72) formed at the front end of the clamping plate (7) extend out of the front ends of the upper insulator (5) and the lower insulator (6) and are respectively arranged on the inner walls of the two sides of the slot pair (10).

4. The TYPE C plug connector of claim 1, wherein: the rubber core main body (1) comprises a bottom shell (11) and an upper cover (12), and the bottom shell (11) and the upper cover (12) are mutually fastened and fixed together.

5. The TYPE C plug connector of claim 4, wherein: a first EMI elastic sheet (13) is arranged in the upper cover (12), a plurality of reverse first elastic hooks (131) are formed at the front end of the first EMI elastic sheet (13) in a stamping mode, and the first elastic hooks (131) extend downwards out of the lower end face of the upper cover (12) and are arranged in the opposite slots (10); the bottom shell (11) is internally provided with a second EMI elastic sheet (14), the front end of the second EMI elastic sheet (14) is stamped to form a plurality of reverse second elastic hooks (141), and the second elastic hooks (141) extend upwards out of the upper end face of the bottom shell (11) and are arranged in the opposite slots (10).

6. The TYPE C plug connector of claim 5, wherein: the upper cover (12) is fixed with the first EMI elastic sheet (13) into a whole in an in-mold injection molding mode; the bottom shell (11) is fixed with the second EMI elastic sheet (14) into a whole in an in-mold injection molding mode.

7. The TYPE C plug connector of claim 6, wherein: the first EMI elastic sheet (13) is provided with a plurality of first hole sites (132), and the upper cover (12) is locally and integrally fixed in the first hole sites (132); the second EMI elastic sheet (14) is provided with a plurality of second hole positions (142), and the bottom shell (11) is locally and integrally fixed in the second hole positions (142).

8. The TYPE C plug connector of claim 2, wherein: a plurality of first rectangular platforms (51), first cylinders (52), first rectangular grooves (53) and first cylindrical grooves (54) are formed on the lower end face of the upper insulator (5); a plurality of second rectangular platforms (61), second cylinders (62), second rectangular grooves (63) and second cylindrical grooves (64) are formed in the upper end face of the lower insulator (6), the first rectangular platforms (51) and the first cylinders (52) are embedded into the second rectangular grooves (63) and the second cylindrical grooves (64) respectively, and the second rectangular platforms (61) and the second cylinders (62) are embedded into the first rectangular grooves (53) and the first cylindrical grooves (54) respectively.

9. The TYPE C plug connector of claim 8, wherein: the upper end face of the upper insulator (5) is also provided with a first positioning column (55), and the first positioning column (55) is embedded into a first positioning hole (101) of the rubber core main body (1); and the lower end face of the lower insulator (6) is also provided with a second positioning column (65), and the second positioning column (65) is embedded into a second positioning hole (102) of the rubber core main body (1).

10. The TYPE C plug connector of any of claims 1-4, wherein: the rear sides of the upper end face and the lower end face of the rubber core main body (1) are respectively provided with an inverted buckle (103), and the inverted buckles (103) are clamped into clamping holes (41) formed in the rear end of the shell (4); the edge of the front end opening of the shell (4) is provided with a flange (42) which is turned from outside to inside, and the flange (42) is arranged on the periphery of the front end of the rubber core main body (1).

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