Electric connector

Abstract

The invention provides an electric connector, and relates to the technical field of electronic equipment. The electric connector comprises a drawing shell, an upper terminal assembly, a middle iron sheet and a lower terminal assembly. The drawing shell is arranged to be in a rectangular barrel shape. The upper terminal assembly comprises an upper-layer terminal and an upper tongue piece, and the upper-layer terminal is arranged on the upper tongue piece through injection molding; two elastic contact parts are oppositely arranged on the middle iron sheet along the A direction; the lower terminal assembly comprises a lower-layer terminal and a lower tongue piece, and the lower-layer terminal is arranged on the lower tongue piece in an injection molding manner; wherein the middle iron sheet is fixedly arranged between the upper tongue piece and the lower tongue piece, the drawing shell is arranged on the upper tongue piece and the lower tongue piece in a hooping mode, and the two contact parts abut against the two side walls, oppositely arranged in the A direction, of the drawing shell in a one-to-one correspondence mode respectively. According to the electric connector, the connection strength, the connection stability and the impact resistance can be improved, so that the use experience and the use safety are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of electronic equipment, and in particular to an electric connector. Background Art

[0002] With the rapid development of electronic technology, electrical connectors have become an indispensable component in electronic equipment. TYPE-C connectors can be plugged in on both sides because of their double-row terminals. Due to this feature, TYPE-C connectors are widely used in electrical connectors. However, the existing TYPE-C connectors with two rows of terminals usually insert the two rows of terminals into the insulating body one by one, and then use other auxiliary components to fix the position of the terminals, and finally place the insulating body in the metal shell, resulting in poor connection strength, connection stability and impact resistance. As a result, there is a situation where the structures are scattered from each other, resulting in reduced user experience and safety. Summary of the invention

[0003] An object of the present invention is to provide an electrical connector which can improve connection strength, connection stability and impact resistance, thereby improving user experience and safety.

[0004] To achieve this object, the present invention adopts the following technical solutions:

[0005] Electrical connector, comprising:

[0006] A pumping shell, wherein the pumping shell is configured in a rectangular cylindrical shape;

[0007] An upper terminal assembly, comprising an upper terminal and an upper tongue, wherein the upper terminal is injection-molded and arranged on the upper tongue;

[0008] The middle iron sheet has two elastic contact parts arranged opposite to each other along the direction A;

[0009] A lower terminal assembly, comprising a lower terminal and a lower tongue, wherein the lower terminal is injection-molded and arranged on the lower tongue;

[0010] Among them, the middle iron sheet is fixedly arranged between the upper tongue piece and the lower tongue piece, the withdrawal shell hoop is arranged on the upper tongue piece and the lower tongue piece, and the two contact parts are respectively in one-to-one contact with the two side walls of the withdrawal shell that are arranged opposite to each other along the A direction.

[0011] As a further technical solution, the second end of the draw-out shell is provided with an abutment portion, which extends in a ring shape along the circumference of the draw-out shell, and the middle iron sheet, the upper tongue piece and the lower tongue piece are all provided with abutment shoulders that can abut against the abutment portion.

[0012] As a further technical solution, the middle iron sheet is provided with injection-molded through holes that allow the adhesive colloid to pass through.

[0013] As a further technical solution, a plurality of the injection through holes are provided, and the plurality of the injection through holes are staggeredly arranged on the middle iron sheet.

[0014] As a further technical solution, along direction A, two first limiting portions are relatively arranged on the middle iron sheet, and two first limiting grooves are correspondingly arranged on the upper tongue piece. When the middle iron sheet is fixedly arranged between the upper tongue piece and the lower tongue piece, the two first limiting portions are limitedly arranged in the two first limiting grooves one by one.

[0015] As a further technical solution, the electrical connector further comprises an inner shell, the inner shell comprising a connecting tube and a connecting plate fixedly connected to the connecting tube, the connecting tube is sleeved on the drawing shell, and the connecting plate abuts against an end surface of the lower tongue piece away from the upper tongue piece;

[0016] Along the A direction, two second limiting portions are spaced apart on the connecting plate, and both of the two second limiting portions extend and bend toward the direction close to the upper tongue piece, and both are in limiting contact with the upper end surface of the lower tongue piece.

[0017] As a further technical solution, a plurality of first clamping parts are arranged at intervals on the connecting plate, a second clamping part is arranged corresponding to the end surface of the lower tongue piece away from the upper tongue piece, and the plurality of first clamping parts are limitedly clamped to the plurality of second clamping parts one by one.

[0018] As a further technical solution, the electrical connector also includes a shell, which is arranged on the side of the upper tongue piece away from the lower tongue piece. Along the direction A, two third limiting portions are relatively arranged on the shell, and the two third limiting portions extend and bend in the direction close to the lower tongue piece, and both are limitedly abutted against the end face of the lower tongue piece away from the upper tongue piece.

[0019] As a further technical solution, two second limiting grooves are arranged on the end surface of the lower tongue piece facing away from the upper tongue piece, and the two third limiting portions are correspondingly and limitatively engaged with the two second limiting grooves.

[0020] As a further technical solution, at least one limiting column is arranged on the end surface of the upper tongue piece facing away from the lower tongue piece, and an avoidance groove allowing the corresponding limiting column to pass through is arranged on the outer shell.

[0021] Compared with the prior art, the electrical connector provided by the present invention has the following technical advantages:

[0022] Since the middle iron sheet is fixedly arranged between the upper tongue sheet and the lower tongue sheet, and the draw-out shell hoop is arranged on the upper tongue sheet and the lower tongue sheet, the relative positions of the middle iron sheet, the upper tongue sheet and the lower tongue sheet are fixed by limiting the position of the cylindrical draw-out shell, and the self-connection strength of the electrical connector is improved, thereby improving the connection stability and impact resistance, reducing the risk of the various structures of the electrical connector being separated from each other, so as to improve the user experience and use safety. At the same time, since the two contact portions relatively arranged along the A direction on the middle iron sheet are respectively abutted against the two side walls relatively arranged along the A direction on the draw-out shell in a one-to-one correspondence, the middle iron sheet and the draw-out shell are connected to ensure the signal transmission effect of the electrical connector, and the two contact portions are abutted against the draw-out shell to further improve the self-connection strength of the electrical connector, thereby further improving its use experience and use safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments of the present invention. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the contents of the embodiments of the present invention and these drawings without paying any creative work.

[0024] Figure 1 is a disassembly diagram of an electrical connector provided by an embodiment of the present invention;

[0025] Figure 2 is a cross-sectional view of an electrical connector provided by an embodiment of the present invention;

[0026] Figure 3 is a schematic structural diagram of an electrical connector provided by an embodiment of the present invention;

[0027] Figure 4 is a schematic diagram of a portion of the structure of an electrical connector provided by an embodiment of the present invention from a first viewing angle;

[0028] Figure 5 is a partial structural schematic diagram of an electrical connector provided by an embodiment of the present invention from a second viewing angle;

[0029] Figure 6 is a cross-sectional view of the contact portion and the drawer shell in the electrical connector provided by the embodiment of the present invention in abutment with each other;

[0030] Figure 7 It is a schematic structural diagram of a middle iron sheet in an electrical connector provided by an embodiment of the present invention;

[0031] Figure 8 It is a schematic structural diagram of an inner shell in an electrical connector provided by an embodiment of the present invention.

[0032] In the figure:

[0033] 100, extraction shell; 110, abutment portion;

[0034] 210, upper terminal; 220, upper tongue; 222, limiting column;

[0035] 300, middle iron sheet; 301, abutting shoulder; 310, contact portion; 320, injection molding through hole; 330, first limiting portion;

[0036] 410, lower terminal; 420, lower tongue; 422, second limiting groove;

[0037] 500, inner shell; 510, connecting tube; 520, connecting plate; 521, second limiting portion; 522, first clamping portion;

[0038] 600, housing; 610, third limiting portion. DETAILED DESCRIPTION

[0039] Before any embodiments of the application are explained in detail, it is to be understood that the application is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the above drawings.

[0040] In this application, the terms "comprises", "includes", "has" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device that includes a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of more restrictions, an element defined by the sentence "comprises a ..." does not exclude the presence of other identical elements in the process, method, article or device that includes the element.

[0041] In this application, the term "and / or" is a description of the association relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this application generally indicates that the related objects before and after are in an "and / or" relationship.

[0042] In the present application, the terms "connect", "combine", "couple", and "install" may refer to direct connection, combination, coupling, or installation, or indirect connection, combination, coupling, or installation. For example, direct connection refers to two parts or components being connected together without the need for an intermediate piece, and indirect connection refers to two parts or components being connected to at least one intermediate piece respectively, and the two parts or components being connected via the intermediate piece. In addition, "connect" and "couple" are not limited to physical or mechanical connections or couplings, and may include electrical connections or couplings.

[0043] In the present application, it will be understood by those of ordinary skill in the art that relative terms (e.g., "about," "approximately," "substantially," etc.) used in conjunction with quantities or conditions include the values ​​and have the meaning indicated by the context. For example, the relative terms include at least the degree of error associated with the measurement of a specific value, the tolerances caused by manufacturing, assembly, and use associated with a specific value, and the like. Such terms should also be considered to disclose a range defined by the absolute values ​​of the two endpoints. Relative terms may refer to plus or minus a certain percentage (e.g., 1%, 5%, 10% or more) of the indicated value. Numerical values ​​that do not use relative terms should also be disclosed as specific values ​​with tolerances. In addition, "substantially" may refer to plus or minus a certain degree (e.g., 1 degree, 5 degrees, 10 degrees or more) on the basis of the indicated angle when expressing a relative angular position relationship (e.g., substantially parallel, substantially perpendicular).

[0044] In this application, it will be understood by those skilled in the art that the function performed by a component can be performed by one component, multiple components, one part, or multiple parts. Similarly, the function performed by a part can also be performed by one part, one component, or a combination of multiple parts.

[0045] In the present application, the terms "upper", "lower", "left", "right", "front", "back" and other directional words are described based on the orientation and positional relationship shown in the accompanying drawings, and should not be understood as limiting the embodiments of the present application. In addition, in the context, it is also necessary to understand that when it is mentioned that an element is connected to another element "upper" or "lower", it can not only be directly connected to another element "upper" or "lower", but also indirectly connected to another element "upper" or "lower" through an intermediate element. It should also be understood that directional words such as upper side, lower side, left side, right side, front side, back side, etc. not only represent the positive orientation, but can also be understood as the lateral orientation. For example, the bottom can include directly below, lower left, lower right, lower front, and lower back, etc.

[0046] Combination Figures 1 to 8As shown, the electrical connector provided in this embodiment can improve the connection strength, connection stability and impact resistance, thereby improving the user experience and safety of use. Specifically, the electrical connector includes a drawer shell 100, an upper terminal assembly, a middle iron sheet 300 and a lower terminal assembly; the drawer shell 100 is set in a rectangular cylindrical shape; the upper terminal assembly includes an upper terminal 210 and an upper tongue piece 220, and the upper terminal 210 is injection-molded on the upper tongue piece 220; along the A direction, two elastic contact portions 310 are relatively arranged on the middle iron sheet 300; the lower terminal assembly includes a lower terminal 410 and a lower tongue piece 420, and the lower terminal 410 is injection-molded on the lower tongue piece 420; wherein, the middle iron sheet 300 is fixedly arranged between the upper tongue piece 220 and the lower tongue piece 420, the drawer shell 100 is clamped on the upper tongue piece 220 and the lower tongue piece 420, and the two contact portions 310 are respectively correspondingly abutted with two side walls of the drawer shell 100 that are relatively arranged along the A direction.

[0047] Since the middle iron sheet 300 is fixedly arranged between the upper tongue sheet 220 and the lower tongue sheet 420, and the draw-out shell 100 is clamped between the upper tongue sheet 220 and the lower tongue sheet 420, the relative positions of the middle iron sheet 300, the upper tongue sheet 220 and the lower tongue sheet 420 are fixed by limiting the position of the cylindrical draw-out shell 100, and the self-connection strength of the electrical connector is improved, thereby improving the connection stability and impact resistance, reducing the risk of the various structures of the electrical connector being separated from each other, so as to improve the user experience and use safety. At the same time, since the two contact portions 310 relatively arranged along the A direction on the middle iron sheet 300 are respectively abutted against the two side walls relatively arranged along the A direction on the draw-out shell 100 in a one-to-one correspondence, the middle iron sheet 300 and the draw-out shell 100 are connected to ensure the signal transmission effect of the electrical connector, and the two contact portions 310 are abutted against the draw-out shell 100 to further improve the self-connection strength of the electrical connector, thereby further improving its use experience and use safety.

[0048] Preferably, the second end of the drawer shell 100 is provided with an abutment portion 110 , which extends in a ring shape along the circumference of the drawer shell 100 , and the middle iron sheet 300 , the upper tongue piece 220 and the lower tongue piece 420 are all provided with an abutment shoulder 301 capable of abutting against the abutment portion 110 .

[0049] Combination Figure 1 and Figure 2As shown, by providing an annular abutment portion 110 at the second end of the draw-out shell 100 to enhance the self-strength of the draw-out shell 100, the overall strength of the electrical connector is further enhanced; at the same time, the abutment shoulders 301 on the middle iron sheet 300, the upper tongue piece 220 and the lower tongue piece 420 are all in abutment with the abutment portion 110 to further enhance the connection strength and tightness between the middle iron sheet 300, the upper tongue piece 220 and the lower tongue piece 420 and the draw-out shell 100, thereby further enhancing the overall strength of the electrical connector. In addition, in order to reduce the difficulty of processing and further enhance the self-strength of the draw-out shell 100, in this embodiment, the abutment portion 110 is integrally formed with the second end of the draw-out shell 100.

[0050] Preferably, the middle iron sheet 300 is provided with an injection through hole 320 allowing the adhesive colloid to pass through.

[0051] Specifically, in the present embodiment, after the middle iron sheet 300 is placed between the upper tongue piece 220 and the lower tongue piece 420, the middle iron sheet 300 is fixedly arranged between the upper tongue piece 220 and the lower tongue piece 420 by bonding with an adhesive colloid; and since the injection molding through hole 320 is arranged on the middle iron sheet 300, during the bonding process, part of the adhesive colloid passes through the injection molding through hole 320 and solidifies; in this way, the fixed connection effect of the middle iron sheet 300 is ensured, and at the same time, the bonding force between the upper tongue piece 220 and the lower tongue piece 420 is increased to further enhance the overall strength of the electrical connector.

[0052] In order to further improve the fixed connection effect of the middle iron sheet 300 and increase the bonding force between the upper tongue piece 220 and the lower tongue piece 420, in this embodiment, a plurality of injection molding through holes 320 are provided, and the plurality of injection molding through holes 320 are staggeredly provided on the middle iron sheet 300. The number of injection molding through holes 320 provided on the middle iron sheet 300 is adaptively set according to actual needs and is not specifically limited here.

[0053] Preferably, along direction A, two first limiting portions 330 are relatively arranged on the middle iron sheet 300, and two first limiting grooves are correspondingly arranged on the upper tongue piece 220. When the middle iron sheet 300 is fixedly arranged between the upper tongue piece 220 and the lower tongue piece 420, the two first limiting portions 330 are limitedly arranged in the two first limiting grooves one by one.

[0054] Combination Figure 5As shown, the two first limiting grooves are both recessed in the direction away from the lower tongue piece 420, and the depths of the two first limiting grooves are the same as the thickness of the corresponding first limiting portion 330, and a storage cavity for accommodating the middle iron sheet 300 is provided on the side of the upper tongue piece 220 close to the lower tongue piece 420, and the two first limiting grooves are both connected to the storage cavity. After the middle iron sheet 300 is placed in the storage cavity, the two first limiting portions 330 are limitedly arranged in the two first limiting grooves one by one, and the upper end surface of the corresponding area in the middle iron sheet 300 is flush with the lower end surface of the upper tongue piece 220. Such a setting, on the one hand, limits the relative position of the middle iron sheet 300 and the upper tongue piece 220 in the axial direction and the A direction of the drawer shell 100; on the other hand, ensures that the upper tongue piece 220 and the lower tongue piece 420 are closely fitted, thereby further improving the strength of the electrical connector.

[0055] Preferably, the electrical connector also includes an inner shell 500, which includes a connecting tube 510 and a connecting plate 520 fixedly connected to the connecting tube 510, the connecting tube 510 is sleeved on the withdrawal shell 100, and the connecting plate 520 abuts against the end surface of the lower tongue piece 420 facing away from the upper tongue piece 220; along the A direction, two second limiting portions 521 are spaced apart on the connecting plate 520, and the two second limiting portions 521 both extend and bend in a direction close to the upper tongue piece 220, and both abut against the upper end surface of the lower tongue piece 420.

[0056] Specifically, when the connecting tube 510 is sleeved on the drawer shell 100, the abutting portion 110 is fixedly connected to the inner wall of the connecting tube 510, thereby improving the connection strength between the outer shell 600 and the drawer shell 100 and realizing the conduction between the inner shell 500 and the middle iron sheet 300. By providing two second limiting portions 521 that can be limitedly abutted with the upper end surface of the lower tongue piece 420, the connection strength between the inner shell 500 and the lower tongue piece 420 is further improved, thereby further improving the overall connection strength and structural stability of the electrical connector.

[0057] Furthermore, a plurality of first clamping parts 522 are arranged at intervals on the connecting plate 520, and a second clamping part is correspondingly arranged on the end surface of the lower tongue piece 420 facing away from the upper tongue piece 220, and the plurality of first clamping parts 522 are clamped one by one to the plurality of second clamping parts. Such arrangement reduces the difficulty of assembling the inner shell 500, and further limits the relative position of the inner shell 500 and the lower tongue piece 420 in the axial direction and the A direction of the drawing shell 100, so as to further improve the connection strength and structural stability. The number and position of the first clamping parts 522 are adaptively adjusted according to the actual situation, and are not specifically limited here.

[0058] Preferably, the electrical connector further comprises a housing 600, which is arranged on a side of the upper tongue piece 220 away from the lower tongue piece 420. Along the A direction, two third limiting portions 610 are arranged on the housing 600 in a relative manner. The two third limiting portions 610 extend and bend in a direction close to the lower tongue piece 420, and are both in position-limiting contact with the end face of the lower tongue piece 420 away from the upper tongue piece 220. By providing the two third limiting portions 610 in position-limiting contact with the lower end face of the lower tongue piece 420, the connection strength and connection tightness between the housing 600 and the lower tongue piece 420 are improved, thereby improving the overall strength and impact resistance of the electrical connector. In order to further improve the self-strength of the housing 600, in this embodiment, the housing 600 and the two third limiting portions 610 are integrally formed.

[0059] Preferably, two second limiting grooves 422 are arranged on the end surface of the lower tongue piece 420 away from the upper tongue piece 220, and the two third limiting portions 610 are correspondingly limited and clamped in the two second limiting grooves 422. The depth of the second limiting grooves 422 is consistent with the thickness of the third limiting portions 610. When the two third limiting portions 610 are correspondingly limited and clamped in the two second limiting grooves 422, the third limiting portions 610 are flush with the lower end surface of the lower tongue piece 420. In this way, on the one hand, the third limiting portions 610 cooperate with the corresponding second limiting grooves 422 to limit the relative position of the housing 600 and the lower tongue piece 420 in the axial direction of the drawing shell 100, so as to further improve the overall strength and impact resistance; on the other hand, since the third limiting portions 610 are located in the corresponding second limiting grooves 422, the space volume of the electrical connector can be reduced.

[0060] Furthermore, at least one limiting column 222 is provided on the end surface of the upper tongue piece 220 facing away from the lower tongue piece 420, and an avoidance groove is provided on the housing 600 to allow the corresponding limiting column 222 to pass through. When the two third limiting portions 610 are limitedly engaged with the two second limiting grooves 422 one by one, the limiting column 222 passes through the corresponding avoidance groove to further improve the connection strength and tightness between the housing 600 and the lower tongue piece 420. The number and position of the limiting column 222 are adaptively set according to actual conditions and are not specifically limited here.

[0061] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, various obvious changes, readjustments and substitutions can be made without departing from the protection scope of the present invention. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention shall be included in the protection scope of the claims of the present invention.

Claims

1. An electrical connector, characterized in that: include: A pumping shell (100), wherein the pumping shell (100) is configured in a rectangular cylindrical shape; An upper terminal assembly comprises an upper terminal (210) and an upper tongue piece (220), wherein the upper terminal (210) is injection-molded and arranged on the upper tongue piece (220); The middle iron sheet (300), along the A direction, has two elastic contact parts (310) arranged opposite to each other on the middle iron sheet (300); A lower terminal assembly comprises a lower terminal (410) and a lower tongue piece (420), wherein the lower terminal (410) is injection-molded and arranged on the lower tongue piece (420); The middle iron sheet (300) is fixedly arranged between the upper tongue piece (220) and the lower tongue piece (420), the draw-out shell (100) is clamped between the upper tongue piece (220) and the lower tongue piece (420), and the two contact portions (310) are respectively in one-to-one contact with two side walls of the draw-out shell (100) that are arranged opposite to each other along the A direction.

2. The electrical connector according to claim 1, characterized in that: The second end of the draw-out shell (100) is provided with an abutment portion (110), and the abutment portion (110) extends in a ring shape along the circumference of the draw-out shell (100), and the middle iron sheet (300), the upper tongue piece (220) and the lower tongue piece (420) are all provided with an abutment shoulder (301) capable of abutting against the abutment portion (110).

3. The electrical connector according to claim 1, characterized in that: The middle iron sheet (300) is provided with an injection through hole (320) that allows the adhesive colloid to pass through.

4. The electrical connector according to claim 3, characterized in that: A plurality of the injection through holes (320) are provided, and the plurality of the injection through holes (320) are staggeredly arranged on the middle iron sheet (300).

5. The electrical connector according to claim 1, characterized in that: Along the A direction, two first limiting portions (330) are relatively arranged on the middle iron sheet (300), and two first limiting grooves are correspondingly arranged on the upper tongue piece (220). When the middle iron sheet (300) is fixedly arranged between the upper tongue piece (220) and the lower tongue piece (420), the two first limiting portions (330) are correspondingly arranged in the two first limiting grooves.

6. The electrical connector according to claim 1, characterized in that: The electrical connector further comprises an inner shell (500), the inner shell (500) comprising a connecting tube (510) and a connecting plate (520) fixedly connected to the connecting tube (510), the connecting tube (510) being sleeved on the drawing shell (100), and the connecting plate (520) being in contact with an end surface of the lower tongue piece (420) facing away from the upper tongue piece (220); Along direction A, two second limiting portions (521) are arranged on the connecting plate (520) at intervals, and the two second limiting portions (521) are both extended and bent in a direction close to the upper tongue piece (220), and are both in limiting contact with the upper end surface of the lower tongue piece (420).

7. The electrical connector according to claim 6, characterized in that: A plurality of first clamping portions (522) are arranged at intervals on the connecting plate (520), and a second clamping portion is correspondingly arranged on the end surface of the lower tongue piece (420) facing away from the upper tongue piece (220), and the plurality of first clamping portions (522) are limitatively clamped to the plurality of second clamping portions one by one.

8. The electrical connector according to claim 6, characterized in that: The electrical connector also includes a shell (600), which is arranged on a side of the upper tongue piece (220) facing away from the lower tongue piece (420). Along direction A, two third limiting portions (610) are relatively arranged on the shell (600), and the two third limiting portions (610) extend and bend in a direction close to the lower tongue piece (420), and are both in limiting contact with the end face of the lower tongue piece (420) facing away from the upper tongue piece (220).

9. The electrical connector according to claim 8, characterized in that: Two second limiting grooves (422) are arranged on the end surface of the lower tongue piece (420) facing away from the upper tongue piece (220), and the two third limiting portions (610) are correspondingly limitedly engaged with the two second limiting grooves (422).

10. The electrical connector according to claim 8, characterized in that: At least one limiting column (222) is provided on the end surface of the upper tongue piece (220) facing away from the lower tongue piece (420), and an avoidance groove allowing the corresponding limiting column (222) to pass through is provided on the housing (600).

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