ELECTRICAL CONNECTOR

Abstract

An includes an insulation body, multiple terminals, an inner metal shell, and an outer metal shell. The insulation body has a base and a tongue located in a front end of the base. The terminals are fixedly arranged in the base in upper and lower rows. Each terminal has a contact portion exposed to an upper surface or a lower surface of the tongue. The inner metal shell has a covering portion disposed on the upper surface of the tongue, and an extending portion extending from the covering portion to the base, and covering the base. The outer metal shell wraps the inner metal shell.

Description

FIELD OF THE INVENTION

The present invention relates to an electrical connector, and more particularly to an electrical connector having a good shielding effect.

BACKGROUND OF THE INVENTION

Chinese Patent CN201320378153.0 discloses, in paragraph [0008] of the specification, an electrical connector, which includes an insulation body, a first terminal group retained to the insulation body and a shielding member. The insulation body includes a base and a tongue extending forward. The tongue has a first surface and a second surface disposed opposite to each other. The first terminal group is exposed to the first surface, and the shielding member is disposed at the tongue and located between the first surface and the second surface. The first terminal group includes a grounding terminal. The grounding terminal is provided with a contact portion protruding towards the shielding member and contacting the shielding member. Paragraph [0020] discloses that the shielding member is integrally formed at a mating plate, the first terminal group and the second terminal group are oppositely assembled to the mating plate and then assembled forward to an assembly frame along with the mating plate, forming the insulation body. However, when the electrical connector of such a structure is used for transmitting high-speed signals, electromagnetic radiation produced by the first terminal group and the second terminal group is easy to leak backward, resulting in that crosstalk is produced during signal transmission at tails of the first terminal group and the second terminal group, which affects signal transmission quality of the electrical connector. In addition, terminals of such an electrical connector are simultaneously assembled to the first surface and the second surface, and as there are more terminals and the tongue is smaller, operations are inconvenient, which easily results in that the terminals are not mounted firmly and tilt upward, damaging the whole electrical connector.

Therefore, a heretofore unaddressed need exists in the art to address the aforementioned deficiencies and inadequacies.

SUMMARY OF THE INVENTION

In one aspect, the present invention relates to an electrical connector of which upper and lower grounding plates can cover a base portion of an insulation body to increase coverage of an inner metal shell and achieve a good shielding effect.

In certain embodiments, an electrical connector includes an insulation body, multiple terminals, an inner metal shell, and an outer metal shell. The insulation body has a base and a tongue located in a front end of the base. The multiple terminals are fixedly arranged in the base in upper and lower rows. Each of the upper row of terminals has a contact portion exposed to an upper surface, and each of the lower row of terminals has a contact portion exposed to a lower surface of the tongue. The inner metal shell has at least one covering portion disposed on the upper surface of the tongue, and at least one extending portion extending from the covering portion to the base, and the extending portion covers the base. The outer metal shell wraps the inner metal shell externally.

In one embodiment, the extending portion has at least one contacting arm, and the contacting arm urges against an inner wall of the outer metal shell.

In one embodiment, the end of the contacting arm bends downward to form a positioning portion, the base is provided with a concave slot corresponding to the positioning portion, and the positioning portion is received in the concave slot.

In one embodiment, a first receiving space is depressed from the base, and the extending portion is accommodated in the first receiving space.

In one embodiment, the inner metal shell further has a connection portion for vertically connecting the covering portion and the extending portion.

In one embodiment, the inner metal shell includes an upper grounding plate and a lower grounding plate, the upper grounding plate covers the upper surface of the tongue, and the lower grounding plate adjoins the lower surface of the tongue.

In one embodiment, each of two sides of the tongue is provided with a reserving slot, each of two side walls of the upper grounding plate is provided with a mating portion, each of two side walls of the lower grounding plate is provided with a fixing portion corresponding to the mating portion, and the mating portions and the fixing portions are accommodated in the reserving slot in a mutually mating manner to enable the inner metal shell to wrap a rear end of the tongue.

In one embodiment, the lower grounding plate has a stopping portion, and the stopping portion adjoins a lower surface of the base.

In one embodiment, the upper row of terminals and the lower row of terminals respectively include at least two grounding terminals. The grounding terminals are located at edges of the tongue and are each provided with a protruding portion in a front end thereof. The protruding portions partially protrude beyond the edges of the tongue.

In one embodiment, the upper row terminal and the lower row terminal are symmetrically arranged on the tongue, each terminal in the upper row terminal has a first rear portion disposed in the base, each terminal in the lower row terminal has a second rear portion disposed in the base, and the first rear portion and the second rear portion are arranged in two rows.

In one embodiment, the electrical connector further includes a middle grounding plate. The middle grounding plate includes a flat plate portion retained in the tongue and located between the upper row terminal and the lower row terminal, and a vertical portion extending downward from a rear end of the flat plate portion, and the vertical portion is located between the first rear portion and the second rear portion.

In one embodiment, a snap-fit slot depressed inward is formed on each of the two sides of the tongue, and the flat plate portion is partially exposed to the snap-fit slot.

In one embodiment, the tongue is assembled on the base, a lower surface of the base has a second receiving space, the insulation body further includes a plastic block, and the plastic block is accommodated in the second receiving space and assembled on the base.

Compared with the related art, the present invention has the following beneficial effects: in the electrical connector, the inner metal shell has the extending portion covering an upper surface of the base, which increases coverage of the inner metal shell, effectively improves signal transmission quality at the end of the terminals and improves signal transmission stability of the whole electrical connector. The insulation body is assembled by the base, the plastic block and the tongue, which simplifies the manufacturing process of the insulation body and reduces the manufacturing cost of the electrical connector.

These and other aspects of the present invention will become apparent from the following description of the preferred embodiment taken in conjunction with the following drawings, although variations and modifications therein may be effected without departing from the spirit and scope of the novel concepts of the disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings illustrate one or more embodiments of the invention and together with the written description, serve to explain the principles of the invention. Wherever possible, the same reference numbers are used throughout the drawings to refer to the same or like elements of an embodiment.

FIG. 1 is a schematic three-dimensional exploded view of an electrical connector according to one embodiment of the present invention.

FIG. 2 is a schematic partial three-dimensional exploded view of an electrical connector according to one embodiment of the present invention.

FIG. 3 is a schematic three-dimensional assembly view of an electrical connector according to one embodiment of the present invention.

FIG. 4 is a sectional view of the electrical connector according to one embodiment of the present invention.

FIG. 5 is a schematic three-dimensional exploded view of a mating connector according to one embodiment of the present invention.

FIG. 6 is a schematic three-dimensional assembly view of a mating connector according to one embodiment of the present invention.

FIG. 7 is a sectional view when an electrical connector according to one embodiment of the present invention mates a mating connector.

FIG. 8 is a schematic three-dimensional exploded view of a second embodiment of an electrical connector according to one embodiment of the present invention.

DESCRIPTION OF REFERENCE NUMERALS

Electrical connector	Insulation body 1	Base 1	First receiving space
100			111
Concave slot 112	Limiting slot 113	Second receiving	Tongue 12
		space 114
Upper surface 121	Lower surface 122	Front surface 123	Side surface 124
Snap-fit slot 1241	Reserving slot 1242	Barrier 125	Front section 1251
Rear section 1252	Flat plate portion	Terminal receiving	Plastic block 13
	1253	slot 126
Terminal 2	Upper row terminal	First mating portion	First rear portion 212
	21	211
First connection	Grounding terminal	Protruding portion	Lower row terminal
portion 213	23	231	22
Second mating	Second rear portion	Second connection	Middle grounding
portion 221	222	portion 223	plate 3
Body portion 31	Vertical portion 32	Grounding pin 33	Inner metal shell 4
Upper grounding	Covering portion 411	Extending portion	Contacting arm 4121
plate 41		412
Positioning portion	Connection portion	Mating portion 414	Lower grounding
4122	413		plate 42
Fixing portion 421	Stopping portion 422	Outer metal shell 5	Insertion space 501
Top wall 51	Abutting portion 511	Bottom wall 52	Side wall 53
Soldering pin 531	Butting connector	Plastic body 201	Contact terminal 202
	200
Shielding casing 203	Retained elastic	Intermediate	Butting cavity 206
	piece 204	shielding sheet 205
First soldering	Second soldering
portion 214	portion 224

DETAILED DESCRIPTION OF THE INVENTION

The present invention is more particularly described in the following examples that are intended as illustrative only since numerous modifications and variations therein will be apparent to those skilled in the art. Various embodiments of the invention are now described in detail. Referring to the drawings, like numbers indicate like components throughout the views. As used in the description herein and throughout the claims that follow, the meaning of “a”, “an”, and “the” includes plural reference unless the context clearly dictates otherwise. Also, as used in the description herein and throughout the claims that follow, the meaning of “in” includes “in” and “on” unless the context clearly dictates otherwise. Moreover, titles or subtitles may be used in the specification for the convenience of a reader, which shall have no influence on the scope of the present invention.

It will be understood that when an element is referred to as being “on” another element, it can be directly on the other element or intervening elements may be present therebetween. In contrast, when an element is referred to as being “directly on” another element, there are no intervening elements present. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items.

Furthermore, relative terms, such as “lower” or “bottom” and “upper” or “top,” may be used herein to describe one element's relationship to another element as illustrated in the Figures. It will be understood that relative terms are intended to encompass different orientations of the device in addition to the orientation depicted in the Figures. For example, if the device in one of the figures is turned over, elements described as being on the “lower” side of other elements would then be oriented on “upper” sides of the other elements. The exemplary term “lower”, can therefore, encompasses both an orientation of “lower” and “upper,” depending of the particular orientation of the figure. Similarly, if the device in one of the figures is turned over, elements described as “below” or “beneath” other elements would then be oriented “above” the other elements. The exemplary terms “below” or “beneath” can, therefore, encompass both an orientation of above and below.

As used herein, “around”, “about” or “approximately” shall generally mean within 20 percent, preferably within 10 percent, and more preferably within 5 percent of a given value or range. Numerical quantities given herein are approximate, meaning that the term “around”, “about” or “approximately” can be inferred if not expressly stated.

As used herein, the terms “comprising”, “including”, “carrying”, “having”, “containing”, “involving”, and the like are to be understood to be open-ended, i.e., to mean including but not limited to.

As shown in FIGS. 3 and 6, an electrical connector 100 according to certain embodiments of the present invention is an electrical connector socket that supports high-speed data transmission, and a mating connector 200 is an electrical connector plug that supports high-speed data transmission.

As shown in FIGS. 1-3, the electrical connector 100 includes an insulation body 1, multiple terminals 2 fixed disposed at the insulation body 1; a middle grounding plate 3 fixed disposed at the insulation body 1; an inner metal shell 4 covering and fixed onto the insulation body 1; and an outer metal shell 5 framed outside the insulation body 1 and the inner metal shell 4, to form an insertion space 501. The outer metal shell 5 has multiple soldering pins 531, and the soldering pins 531 can be correspondingly soldered onto a grounding circuit of a circuit board (not shown).

As shown in FIGS. 5-7, the mating connector 200 includes a plastic body 201, multiple contact terminals 202 fixed to the plastic body 201, a shielding casing 203 wraps the plastic body 201, a middle shielding sheet 205 fixedly disposed in the plastic body 201, two retaining elastic sheets 204 respectively fixedly disposed to two sides of the plastic body 201, and a mating cavity 206 disposed in a front end of the plastic body 201. When the mating connector 200 is inserted into the insertion space 501 of the electrical connector 100, in addition to that the contact terminals 202 are connected with the corresponding multiple terminals 2, the retaining elastic sheets 204 may contact the middle grounding plate 3 to form a first grounding shielding structure, thus preventing electromagnetic radiation from passing through the insulation body 1 to leak backward to interfere signal transmission of the terminals 2. Moreover, the outer metal shell 5 and the shielding casing 203 form a second grounding shielding structure, which can thus effectively form a wholly surrounded shielding structure.

As shown in FIGS. 1 and 2, in an electrical connector according to a first embodiment of the present invention, the insulation body 1 includes a base 11 and a tongue 12 assembled to a front end of the base 11, and a plastic block 13 superimposed below the base 11. In other embodiments, the base 11, the tongue 12 and the plastic block 13 may be integrally formed or formed in any other manners, which is not limited herein.

As shown in FIGS. 1, 4 and 7, a first receiving space 111 is depressed from an upper surface of the base 11 along a vertical direction. Two concave slots 112 are depressed from a rear end of the first receiving space 111. In the vertical direction, the depth of the concave slots 112 is greater than that of the first receiving space 111. The upper surface of the base 11 is further provided with a limiting slot 113, and the limiting slot 113 is in communication with a rear end face of the base 11. A lower surface of the base 11 is provided with a second receiving space 114, and the plastic block 13 is assembled in the second receiving space 114. The tongue 12 has an upper surface 121 and a lower surface 122 opposite up and down, and a front surface 123 and two side surfaces 124 connected between the two surfaces. The upper surface 121 and the lower surface 122 are respectively provided with multiple barriers 125 to form multiple terminal receiving slots 126. The barriers 125 further include a front section 1251 and a rear section 1252, and a thickness dimension of the rear section 1252 is greater than that of the front section 1251, to facilitate that the rear section 1252 has a good hot-melting condition when the insulation body 1 is assembled. A snap-fit slot 1241 depressed inward is further formed in a front end of each of the two side surfaces 124. The snap-fit slots 1241 partially accommodate the retaining elastic sheets 204, to enable the retaining elastic sheets 204 to connect the middle grounding plate 3. A reserving slot 1242 is further formed at a rear end of each of the two side surfaces 1241, for reserving assembly space for the inner metal shell 4.

As shown in FIGS. 1, 2 and 4, the multiple terminals 2 include a group of upper row terminals 21 and a group of lower row terminals 22. The upper row terminals 21 are integrally formed with the base 11. Each of the upper row terminals 21 includes a first mating portion 211, a first rear portion 212 and a first connection portion 213 connected between the first mating portion 211 and the first rear portion 212. The first mating portion 211 may extend backward to form the first connection portion 213, the first connection portion 213 may bend downward and extend to form the first rear portion 212 that is vertical, and the first rear portion 212 may bend backward and extend to form a first soldering portion 214 that is horizontal. The lower row terminals 22 are integrally formed with the plastic block 13. Each of the lower row terminals 22 includes a second mating portion 221, a second rear portion 222 and a second connection portion 223 connected between the second mating portion 221 and the second rear portion 222. The second mating portion 221 may extend backward to form the second connection portion 223, the second connection portion 223 may bend downward and extend to form the second rear portion 222 that is vertical, and the second rear portion 222 may bend forward and extend to form a second soldering portion 224 that is horizontal. When the base 11, the tongue 12 and the plastic block 13 are assembled together, an upper surface of the rear section 1252 forms a flat plate portion 1253 through hot melting to retain the first connection portion 213, and a lower surface of the rear section 1252 forms the flat plate portion 1253 through hot melting to retain the second connection portion 223, preventing the terminals 2 from tilting upward in the terminal receiving slot 126. The first mating portion 211 is correspondingly received in the terminal receiving slot 126 and exposed to the upper surface 121. The second mating portion 221 is correspondingly received in the terminal receiving slot 126 and exposed to the lower surface 122. The first rear portions 212 and the second rear portions 222 are arranged in two rows. The upper row terminal 21 and the lower row terminal 22 further respectively include two grounding terminals 23. The grounding terminals 23 are located at edges of the tongue 12 and each has a protruding portion 231 in front ends thereof, and the protruding portions 231 partially protrude beyond the edges of the tongue 12, avoiding worn out of the tongue 12 during mating of the electrical connector 100. The first mating portions 211 and the second mating portions 221 are symmetrically disposed at 180 degrees in the inserting space 501, thus enabling the mating connector 200 to be inserted into the electrical connector 100 in dual orientation.

As shown in FIGS. 1, 4 and 7, the middle grounding plate 3 includes a body portion 31, a vertical portion 32, and multiple grounding pins 33. The body portion 31 is retained into the tongue 12 and located between the upper row terminal 21 and the lower row terminal 22, separates the upper row terminal 21 and the lower row terminal 22, and shields signal interference between the upper row terminal 21 and the lower row terminal 22. The body portion 31 is further partially exposed to the snap-fit slot 1241 and connected with the retaining elastic sheets 204. The vertical portion 32 extends downward from a rear end of the body portion 31, is located between the first rear portions 212 and the second rear portions 222, separates the first rear portion 212 and the second rear portion 222, and shields signal interference between the first rear portions 212 and the second rear portions 222. The multiple grounding pins 33 extend downward from the vertical portion 32, used for being soldered onto a grounding circuit of the circuit board (not shown).

As shown in FIGS. 1, 3 and 4, the outer metal shell 5 includes a top wall 51, a bottom wall 52 and two side walls 53 connecting the top wall 51 and the bottom wall 52. The top wall 51 pierces downward corresponding to the position of the limiting slot 113 to provide an urging portion 511 urging against an inner wall of the limiting slot 113, preventing the outer metal shell 5 from moving forward. In other embodiments, the urging portion 511 may be formed in any other manners, which is not limited herein. A middle portion of each of the side walls 53 extends downward to form a soldering pin 531, a rear end of each of the side walls 53 extends downward to form a soldering pin 531, and the soldering pins 531 are used for being soldered to the circuit board (not shown).

As shown in FIGS. 1 and 4, the inner metal shell 4 includes an upper grounding plate 41 and a lower grounding plate 42. The upper grounding plate 41 includes a covering portion 411, an extending portion 412 and a connection portion 413 vertically connecting the covering portion 411 and the extending portion 412. The covering portion 411 covers the flat plate portion 1253. The extending portion 412 covers an upper surface of the base 11 and is accommodated in the first receiving space 111. Each of two sides of the extending portion 412 has a contacting arm 4121 extending backward and upward. The contacting arms 4121 urges against an inner wall of the outer metal shell 5, to from an electrical connection, making the inner metal shell 4 grounded. The end of each contacting arm 4121 bends downward to form a positioning portion 4122, so that the contacting arm 4121 is in an arc shaped contact with the inner wall of the outer metal shell 5, to facilitate assembling of the outer metal shell 5 to the insulation body 1. The positioning portions 4122 are respectively received in the concave slots 112, preventing the inner metal shell 4 from sliding forward. Each of two side walls of the upper grounding plate 41 is further provided with a mating portion 414, and each of two side walls of the lower grounding plate 42 is provided with a fixing portion 421 corresponding to the mating portion 414. The mating portion 414 and the fixing portion 412 are accommodated in the reserving slots 1242 correspondingly in a mutually mating manner, such that the inner metal shell 4 wraps the insulation body 1. The lower grounding plate 42 further has a stopping portion 422. The stopping portion 422 adjoins a lower surface of the plastic block 13, to firmly assemble the plastic block 13 to the base 11. In other embodiments, the upper grounding plate 41 and the lower grounding plate 42 may be integrally formed, which is not limited herein.

FIG. 8 shows an electrical connector 100 according to a second embodiment of the present invention. The second embodiment is different from the first embodiment in that the electrical connector in the second embodiment is a vertical electrical connector. In this embodiment, the middle grounding plate 3 is not provided with the vertical portion 32, the grounding pin 33 also extends in a direction directly from the body portion 31 to the circuit board (not shown), and the soldering pin 531 extends in a direction from the top wall 51 and the bottom wall 52 to the circuit board (not shown).

As shown in FIGS. 1 and 2, in the electrical connector 100, during assembly, firstly, the base 11 and the upper row terminals 21 are integrally formed, the plastic block 13 and the lower row terminals 21 are integrally formed, and the middle grounding plate 3 is integrally fixed into the tongue 12; secondly, the tongue 12 is inserted into the base 11 from front to rear, and the plastic block 13 is assembled to the base 11 from bottom to top; then, the rear section 1252 is correspondingly hot-melted to retain the terminals 2 onto the tongue 12, the upper grounding plate 41 covers the insulation body 1 downward, and the lower grouping sheet 42 covers the insulation body 1 upward; finally, the outer metal shell 5 is sleeved over the insulation body 1 and correspondingly soldered onto the circuit board (not shown).

In summary, the electrical connector 100 according to certain embodiments of the present invention, among other things, has the following beneficial advantages:

(1) The upper grounding plate 41 has the extending portion 412 covering an upper surface of the base 11, the lower grounding plate 42 has the stopping portion 422 adjoining a lower surface of the plastic block 13, which increases coverage of the inner metal shell 4, can more effectively prevent crosstalk caused by that electromagnetic radiation in the insertion space 501 from leaking backward to interfere tails of the terminals 2 when the electrical connector 100 transmits high-speed signals, and improves signal transmission quality of the electrical connector 100.

(2) The middle grounding plate 3 has the vertical portion 32 located between the first rear portion 212 and the second rear portion 222, which effectively shields telecommunication interference between the first rear portions 212 and the second rear portions 222, and enhances signal transmission stability of the electrical connector 100.

(3) The insulation body 1 is composed of the base 11, the tongue 12 and the plastic block 13, which reduces the difficulty of integrally forming the insulation body 1, improves the manufacturing speed of the insulation body 1, and saves the manufacturing cost of the electrical connector 100.

(4) During assembly, the tongue 12 adopts a hot melting method to retain the terminals 2, which makes the terminals 2 not easy to tilt upward on the tongue 12, and prolongs the service life of the electrical connector 100.

The foregoing description of the exemplary embodiments of the invention has been presented only for the purposes of illustration and description and is not intended to be exhaustive or to limit the invention to the precise forms disclosed. Many modifications and variations are possible in light of the above teaching.

The embodiments are chosen and described in order to explain the principles of the invention and their practical application so as to activate others skilled in the art to utilize the invention and various embodiments and with various modifications as are suited to the particular use contemplated. Alternative embodiments will become apparent to those skilled in the art to which the present invention pertains without departing from its spirit and scope. Accordingly, the scope of the present invention is defined by the appended claims rather than the foregoing description and the exemplary embodiments described therein.

Claims

1. An electrical connector, comprising: an insulation body, having a base and a tongue located in a front end of the base;an upper row of terminals and a lower row of terminals fixedly arranged in the base, each of the upper row of terminals and the lower row of terminals having a contact portion exposed to an upper surface or a lower surface of the tongue;an inner metal shell, having a covering portion disposed on the upper surface of the tongue, and an extending portion extending from the covering portion toward the base, the extending portion covering the base; andan outer metal shell, wrapping the inner metal shell.

2. The electrical connector according to claim 1, wherein the extending portion has at least one contacting arm, and the contacting arm urges against an inner wall of the outer metal shell.

3. The electrical connector according to claim 2, wherein an end of the contacting arm bends downward to form a positioning portion, the base is provided with a concave slot corresponding to the positioning portion, and the positioning portion is received in the concave slot.

4. The electrical connector according to claim 1, wherein a first receiving space is depressed from the base, and the extending portion is accommodated in the first receiving space.

5. The electrical connector according to claim 1, wherein the inner metal shell further comprises a connection portion for vertically connecting the covering portion and the extending portion.

6. The electrical connector according to claim 1, wherein the inner metal shell comprises an upper grounding plate and a lower grounding plate, the upper grounding plate covers the upper surface of the tongue, and the lower grounding plate adjoins the lower surface of the tongue.

7. The electrical connector according to claim 6, wherein each of two sides of the tongue is provided with a reserving slot, each of two side walls of the upper grounding plate is provided with a mating portion, each of two side walls of the lower grounding plate is provided with a fixing portion corresponding to the mating portion, and each of the mating portions mates with corresponding one of the fixing portions and are accommodated in corresponding one of the reserving slots, such that enable the inner metal shell wraps a rear end of the tongue.

8. The electrical connector according to claim 6, wherein the lower grounding plate comprises a stopping portion, and the stopping portion adjoins a lower surface of the base.

9. The electrical connector according to claim 1, wherein the upper row of terminals and the lower row of terminal respectively comprise at least two grounding terminals, the grounding terminals are located at edges of the tongue and are each provided with a protruding portion in a front end thereof, and the protruding portions partially protrude beyond the edges of the tongue.

10. The electrical connector according to claim 1, wherein the upper row of terminals and the lower row of terminal are symmetrically arranged on the tongue, each terminal in the upper row of terminal has a first rear portion disposed in the base, each terminal in the lower row of terminal has a second rear portion disposed in the base, and the first rear portions and the second rear portions are arranged in two rows.

11. The electrical connector according to claim 10, further comprising a middle grounding plate, wherein the middle grounding plate comprises: a body portion retained in the tongue and located between the upper row terminal and the lower row terminal; anda vertical portion extending downward from a rear end of the body portion, and located between the first rear portions and the second rear portions.

12. The electrical connector according to claim 11, wherein a snap-fit slot depressed inward is formed on each of the two sides of the tongue, and the body portion is partially exposed to the snap-fit slot.

13. The electrical connector according to claim 1, wherein the tongue is assembled on the base, a lower surface of the base has a second receiving space, the insulation body further comprises a plastic block, and the plastic block is accommodated in the second receiving space and assembled on the base.