CN209119397U - Back panel connector - Google Patents

Abstract

The utility model discloses back panel connectors, it includes male end pedestal and female end pedestal, the female end pedestal is plugged on the male end pedestal, not deflective parity mode group is installed on female end pedestal, parity mode group includes the odd module being mutually close to and even module, it is offered in odd module multiple for arranging that the odd module difference of the second cabling group walks line chamber, it is offered in even module multiple for arranging that the even module difference of the first cabling group walks line chamber, the wire laying mode of second cabling group and the first cabling group is not identical, wherein the first cabling group includes differential pair and the return piece that differential pair side is arranged in, the second connecting portion of return piece offers through slot, several connection bridges are provided in through slot, and through slot is separated into several segments by connection bridge.The beneficial effects of the utility model are: it has the advantages that stable structure, impedance matching, installation is stable and return flow path is short.

Description

Back panel connector

Technical field

The utility model relates to high speed connectors, especially back panel connector.

Background technique

Electric connector is other than it will meet general performance requirement, it is also necessary to which electric connector reaches contact well, and work can It leans on, requirement easy to maintain.

High speed connector is used for large-scale communication apparatus, very-high performance server and supercomputer, industrial computer, high-end Equipment etc. is stored, with communication, the fast development of electronics, internet industry, the market scale Fast Growth of high speed connector.

Utility model content

The shortcomings that the purpose of the utility model is to overcome the prior arts provides a kind of back panel connector.

The purpose of this utility model is achieved through the following technical solutions: back panel connector, it includes male end pedestal and mother End group seat, the female end pedestal are plugged on the male end pedestal, and not deflective parity mode group is equipped on female end pedestal, odd Even mould group includes the odd module being mutually close to and even module, is offered in odd module multiple for arranging the odd mould of the second cabling group Block difference walks line chamber, offers in even module multiple for arranging that the even module difference of the first cabling group walks line chamber, the second cabling Group and the first cabling group include differential pair and the return piece that differential pair side is arranged in, and the second connecting portion of return piece offers Through slot is provided with several connection bridges in through slot, and is connected to bridge and through slot is separated into several segments.

Preferably, odd module difference, which walks line chamber and walks line chamber with even module difference, is interspersed, face surprise module difference cabling The first convex block is provided in the even module of chamber, the cooperation of the first convex block is intracavitary in odd module difference cabling, and positive antithesis module difference is walked The second convex block is provided in the odd module of line chamber, the cooperation of the second convex block is intracavitary in even module difference cabling.

Preferably, it is three that odd module difference, which walks line chamber, and walks line chamber, the 5th poor from long the 4th difference that is divided into is short to Divide to walk line chamber, the 6th difference to walk line chamber, positioned at the 4th difference walks line chamber, the 5th difference walks line chamber, the 6th difference walks the two of line chamber The second convex block is provided in the odd module of side, it is three that even module difference, which walks line chamber also, and is divided into first from length is short to Difference walks line chamber, the second difference walks line chamber, third difference walks line chamber, positioned at the first difference walks line chamber, the second difference walks line chamber, Three difference are walked and are provided with the first convex block in the even modules of line chamber two sides, and the first difference walks line chamber, the second difference walks line chamber, third It is intracavitary at least provided with an interconnecting piece that difference walks line chamber, the 4th difference walks line chamber, the 5th difference walks line chamber, the 6th difference cabling.

Preferably, the back side of the first convex block offers the first groove, and the cell wall thickness of the first groove is uniform, and second is convex The back side of block offers the second groove, and the cell wall thickness of the second groove is uniform.

Preferably, it is provided with the first positioning column and the second positioning column being staggered in even module, is offered in odd module and the Second location hole corresponding with the second positioning column is offered in the corresponding first positioning hole of one positioning column and odd module.

Preferably, differential pair includes the first contact, first connecting portion and the first connection-peg, the first contact and first connecting portion One end connection, the other end of first connecting portion connect with the first connection-peg, and return piece further includes the second contact and the second grafting One end of head, the second contact and second connecting portion connects, and the other end of second connecting portion is connect with the second connection-peg.

Preferably, the mounting groove for installing parity mode group is offered on female end pedestal, the rear wall of mounting groove prolongs upwards It stretches to form back side panel, the first limit hole is offered on back side panel, the second limit hole, odd module are offered on the front side wall of mounting groove Alignment on the front side wall of even module is provided with wedge locating block, wedge locating block is mounted in the second limit hole, in even module Offer the elastic hook being mounted in the first limit hole.

Preferably, the left and right sides wall of mounting groove upwardly extends to form muscle wall.

Preferably, multiple slots are offered on the front side wall of female end pedestal, and positioning is offered on the rear wall of female end pedestal Convex block offers the U-type groove for installing female end pedestal on male end pedestal, is provided with grafting block, U on the preceding inner sidewall of U-type groove Locating slot is offered on the rear inner sidewall of type groove, grafting block is coupled in corresponding slot, and locating convex block is fitted to positioning In slot.

The utility model has the advantage that

1, through slot is offered on return piece, realizes impedance matching, and reduce demand of the return piece to material, reduced Production cost；

2, connection bridge shortens return flow path, effectively reduces crosstalk, and increase the structural strength of return piece；

3, parity mode group is by the first convex block and the second convex block, so that around the cabling of the first cabling group and the second cabling group The transmission medium in region becomes odd module and the first convex block and even module by air and the second convex block is formed with cavity Insulator, and the dielectric constant of air is lower than the dielectric constant of plastics, so that the dielectric constant of the transmission medium of routing region is sent out It is raw to change, so that adjustable impedance in claimed range, realizes impedance matching；

4, the first groove is set at the back side of the first convex block, the back side of the second convex block is arranged the second groove, the first groove and The cavity that second groove is formed is air cavity, and the dielectric constant of the intracorporal air of the air chamber is lower than plastics, to transmit The dielectric constant of medium is changed, therefore the air cavity that the first groove and the second groove are formed can be used to adjust resistance It is anti-, so that parity mode group impedance matching；

5, parity mode group realizes parity mode group front and back side positioning by elastic hook and wedge locating block, and passes through Muscle wall is set and guarantees that the normotopia degree for the terminal that product is crimped on pcb board conforms to further such that parity mode group is unbiased It asks.

6, male end pedestal is connected by the way of grafting with female end pedestal, easy for installation, and is firmly installed.

Detailed description of the invention

Fig. 1 is the structural schematic diagram of parity mode group；

Fig. 2 is the configuration schematic diagram of parity mode group；

Fig. 3 is the structural schematic diagram of odd module；

Fig. 4 is the structural schematic diagram of even module；

Fig. 5 is the structural schematic diagram that even module is mounted with the first cabling group；

Fig. 6 is the structural schematic diagram that odd module is mounted with the second cabling group；

Fig. 7 is the distribution schematic diagram of the first groove；

Fig. 8 is the distribution schematic diagram of the second groove；

Fig. 9 is the structural schematic diagram of the first cabling group；

Figure 10 is the first viewing angle constructions schematic diagram of the first cabling group；

Figure 11 is the structural schematic diagram of the utility model；

Figure 12 is the structural schematic diagram of female end pedestal；

Figure 13 is the scheme of installation of elastic hook；

Figure 14 is the structural schematic diagram of the utility model；

Figure 15 is the structural schematic diagram of male end pedestal；

In figure: 1- idol module, 2- surprise module, 3- the first cabling group, 4- the second cabling group, the first convex block of 5-, 6- second are convex Block, 7- interconnecting piece, 8- surprise module difference walk line chamber, and 9- idol module difference walks line chamber, and the first difference of 11- walks line chamber, and 12- second is poor Divide to walk line chamber, 13- third difference walks line chamber, and the 4th difference of 21- walks line chamber, and the 5th difference of 22- walks line chamber, and the 6th difference of 23- is walked Line chamber, the first positioning column of 41-, 42- first positioning hole, the second positioning column of 43-, 44- second location hole, the first groove of 51-, 61- Second groove, 31- differential pair, 32- return piece, the first contact of 311-, 312- first connecting portion, the first connection-peg of 313-, 321- Second contact, 322- second connecting portion, 323- are connected to bridge, 324- through slot, the second connection-peg of 325-, 100- female end pedestal, 101- Mounting groove, 102- muscle wall, the first limit hole of 103-, 104- back side panel, the second limit hole of 105-, 106- elastic hook, 107- Parity mode group, 108- wedge locating block, 140- male end pedestal, 141-U type groove, 142- grafting block, 143- locating slot, 144- are inserted Slot, 145- locating convex block.

Specific embodiment

It is practical new below in conjunction with this to keep the objectives, technical solutions, and advantages of the embodiments of the present invention clearer Attached drawing in type embodiment, the technical scheme in the utility model embodiment is clearly and completely described, it is clear that is retouched The embodiment stated is the utility model a part of the embodiment, instead of all the embodiments.Usually here in attached drawing description and The component of the utility model embodiment shown can be arranged and be designed with a variety of different configurations.

Therefore, requirement is not intended to limit to the detailed description of the embodiments of the present invention provided in the accompanying drawings below The scope of the utility model of protection, but it is merely representative of the selected embodiment of the utility model.Based in the utility model Embodiment, every other embodiment obtained by those of ordinary skill in the art without making creative efforts, all Belong to the range of the utility model protection.

It should also be noted that similar label and letter indicate similar terms in following attached drawing, therefore, once a certain Xiang Yi It is defined in a attached drawing, does not then need that it is further defined and explained in subsequent attached drawing.

In the description of the present invention, it should be noted that the orientation or position of the instructions such as term " on ", "inner", "outside" Set relationship be based on the orientation or positional relationship shown in the drawings or the utility model product using when the orientation usually put Or positional relationship, be merely for convenience of describing the present invention and simplifying the description, rather than the device of indication or suggestion meaning or Element must have a particular orientation, be constructed and operated in a specific orientation, therefore should not be understood as the limit to the utility model System.

In the description of the present invention, it should also be noted that, unless otherwise clearly defined and limited, term " is set Set ", " installation ", " connection " shall be understood in a broad sense, for example, it may be being fixedly connected, may be a detachable connection, or integrally Connection；It can be mechanical connection, be also possible to be electrically connected；Can be directly connected, can also indirectly connected through an intermediary, It can be the connection inside two elements.For the ordinary skill in the art, above-mentioned art can be understood with concrete condition The concrete meaning of language in the present invention.

As shown in Figure 14 and Figure 15, back panel connector, it includes male end pedestal 140 and female end pedestal 100, the female end base Seat 100 is plugged on the male end pedestal 140, and multiple slots 144, multiple slots are offered on the front side wall of female end pedestal 100 144 intervals are arranged side by side, and after opening up slot 144, just will form a rib between two adjacent slots 144, which can guarantee The structural strength of female end pedestal 100 offers locating convex block 145 as shown in figure 13 on the rear wall of female end pedestal 100, such as scheme Shown in 15, the U-type groove 141 for installing female end pedestal 100 is offered on male end pedestal 140, on the preceding inner sidewall of U-type groove 141 It is provided with grafting block 142, locating slot 143 is offered on the rear inner sidewall of U-type groove 141, grafting block 142 is coupled corresponding slot In 144, grafting block 142 and slot 144 are interference fit, further, the insertion end of slot 144 are provided with the wedge shape of opening Opening, consequently facilitating grafting block 142 is inserted into slot 144, locating convex block 145 is fitted in locating slot 143, convex The cooperation of block 145 and locating slot 143 is also interference fit, consequently facilitating locating convex block 145 is inserted into locating slot 143, thus Female end pedestal 100 is quickly mounted on male end pedestal 140, and female end pedestal 100 and male end pedestal after installation 140 will not shake.

In the present embodiment, as shown in figure 11, not deflective parity mode group 107 is installed on female end pedestal 100, is such as schemed Shown in 1, parity mode group 107 includes the odd module 2 being mutually close to and even module 1, as shown in Figure 2, Figure 3 and Figure 4, in even module 1 It is provided with the first positioning column 41 and the second positioning column 43 being staggered, corresponding with the first positioning column 41 is offered in odd module 2 Second location hole 44 corresponding with the second positioning column 43 is offered in a positioning hole 42 and odd module 2, it is preferred that the first positioning The upper right corner of even module 1 is arranged in column 41, and the second positioning column 43 is multiple, and the bottom of even module 1 is arranged in, further , second location hole 44 is blind hole, and the connection of the first positioning column 41 and first positioning hole 42 is interference fit, the second positioning column 43 Connection with second location hole 44 is also interference fit, when the first positioning column 41 and first positioning hole 42 and the second positioning column 43 After working good with second location hole 44, odd module 2 and the even abutting of module 1 and its edge are flushed.

In the present embodiment, it as shown in Fig. 2 ~ Fig. 6, is offered in odd module 2 multiple for arranging the surprise of the second cabling group 4 Module difference walks line chamber 8, offered in even module 1 it is multiple for arranging that the even module difference of the first cabling group 3 walks line chamber 9, In the present embodiment, as shown in figure 3, it is three that odd module difference, which walks line chamber 8, and long it be divided into the 4th difference from being short to and walk line chamber 21, the 5th difference walks line chamber 22, the 6th difference walks line chamber 23, and further, the 4th difference walks line chamber 21 and is located at the interior of odd module 2 Side, the 6th difference walk the outside that line chamber 23 is located at odd module 2, as shown in figure 4, it is three that even module difference, which walks line chamber 9 also, and from Be short to it is long be divided into that the first difference walks line chamber 11, the second difference walks line chamber 12, third difference walks line chamber 13, further, the One difference walks the inside that line chamber 11 is located at even module 1, and third difference walks the outside that line chamber 13 is located at even module 1, in the present embodiment In, odd module difference, which walks line chamber 8 and walks line chamber 9 with even module difference, to be interspersed, and further, the 4th difference is walked line chamber 21 and is located at First difference walks line chamber 11 and the second difference is walked between line chamber 12, the 5th difference walk line chamber 22 be located at the second difference walk line chamber 12 with Third difference is walked between line chamber 13, and the 6th difference walks line chamber 23 and is located at the outside that third difference walks line chamber 13.

In the present embodiment, as shown in Fig. 2 ~ Fig. 6, face surprise module difference is walked and is provided with first in the even module 1 of line chamber 8 Convex block 5, the cooperation of the first convex block 5 are walked in line chamber 8 in odd module difference, and positive antithesis module difference is walked to be arranged in the odd module 2 of line chamber 9 There is the second convex block 6, the cooperation of the second convex block 6 is walked in line chamber 9 in even module difference, passes through the first convex block 5 and odd module difference cabling The cooperation of chamber 8 and the second convex block 6 and even module difference walk the cooperation of line chamber 9, to increase the connection of parity mode group 107 Structural stability, therefore by the first convex block 5 and the second convex block 6, so that 1 install convenient of odd module 2 and even module, improves odd mould Block 2 and the even mounting stability of module 1 and the structural strength of parity mode group, so that parity mode group is unlikely to deform, but also are saved The material for making odd module and even module has been saved, production cost is reduced, specifically, being located at the 4th difference walks line chamber the 21, the 5th Difference walks line chamber 22, is provided with the second convex block 6 in the odd module 2 for the two sides that the 6th difference walks line chamber 23, is located at the first difference Walk line chamber 11, the second difference walks line chamber 12, third difference is walked and is provided with the first convex block 5 in the even modules 1 of 13 two sides of line chamber, lead to The first convex block 5 and the second convex block 6 are crossed, so that the even module difference of 3 cabling of the first cabling group walks line chamber 9 and the second cabling The odd module difference of 4 cablings of group walks line chamber 8 and forms a cavity, so that the cabling of the first cabling group 3 and the second cabling group 4 is all Enclosing the transmission medium in region and by air becoming odd module 2 and formed with the first convex block 5 and even module 1 with the second convex block 6 has The insulator of cavity, and the first convex block 5, the second convex block 6 are the plastics that high molecular material is done, the dielectric constant of air is than modeling The dielectric constant of material is low, so that the dielectric constant of the transmission medium of routing region changes, so that adjustable impedance is requiring In range, impedance matching is realized.

In the present embodiment, the first difference walks line chamber 11, the second difference walks line chamber 12, third difference walks line chamber the 13, the 4th Difference walks line chamber 21, the 5th difference walks line chamber 22, the 6th difference is walked in line chamber 23 at least provided with an interconnecting piece 7,7 energy of interconnecting piece Enough increase the structural soundness of odd module 2 and even module 1, so that it is steady to ensure that the first cabling group 3 and the second cabling group 4 are installed It is qualitative.

In the present embodiment, as shown in Figure 7 and Figure 8, the back side of the first convex block 5 offers the first groove 51, and first The cell wall thickness of groove 51 is uniform, and the back side of the second convex block 6 offers the second groove 61, and the cell wall thickness of the second groove 61 is equal Even, the cavity that the first groove 51 and the second groove 61 are formed is air cavity, the dielectric constant ratio of the intracorporal air of the air chamber Plastics it is low, so that the dielectric constant of transmission medium is changed, therefore the sky that the first groove 51 and the second groove 61 are formed Air cavity can be used to adjust impedance, so that parity mode group impedance matching, and the setting of the first groove 51 and the second groove 61, The weight of odd even module is also reduced, consumptive material is reduced, has saved production cost.

In the present embodiment, such as Fig. 9 and Figure 10, the wire laying mode of the second cabling group 4 and the first cabling group 3 is not identical, and Two cabling groups 4 and the first cabling group 3 include differential pair 31 and the return piece 32 that 31 side of differential pair is arranged in, and differential pair 31 wraps The first contact 311, first connecting portion 312 and the first connection-peg 313 are included, the first contact 311 and one end of first connecting portion 312 connect Connect, the other end of first connecting portion 312 is connect with the first connection-peg 313, further, return piece 32 include the second contact 321, Second connecting portion 322 and the second connection-peg 325, the second contact 321 are connect with one end of second connecting portion 322, second connecting portion 322 other end is connect with the second connection-peg 325, and the first contact 311 and the second contact 321 are closely touched with straight male plug needle, Second connection-peg 325 and the first connection-peg 313 are then used for grafting circuit board, and first connecting portion 312 is then for connecting the first touching First 311 and first connection-peg 313, second connecting portion 322 is then for connecting the second contact 321 and the second connection-peg 325, specific In use process, the length and shape of first connecting portion 312 and second connecting portion 322 can be changed, thus just according to actual needs In the installation of differential pair 31 and return piece 32, and guarantee that the first connection-peg 313 is aligned spacing side by side with the second connection-peg 325 and sets It sets.

In the present embodiment, the second connecting portion 322 of return piece 32 offers through slot 324, and through slot 324 reduces return piece 32 area realizes impedance matching, and through slot 324, and can reduce demand of the return piece 32 to consumptive material, sets in through slot 324 Several connection bridges 323 are equipped with, and is connected to bridge 323 and through slot 324 is separated into several segments, by being connected to bridge 323, so that reflux Path is repeatedly connected to, and shortens return flow path by communicating position, effectively reduces crosstalk.

In the present embodiment, it as shown in Figure 11 ~ Figure 13, is offered on female end pedestal 100 for installing parity mode group 107 Mounting groove 101, the rear wall of mounting groove 101 upwardly extend to form back side panel 104, and the first limit hole is offered on back side panel 104 103, it offers the second limit hole 105 on the front side wall of mounting groove 101, is aligned setting on the front side wall of odd module 2 and even module 1 There is wedge locating block 108, wedge locating block 108 is mounted in the second limit hole 105, is offered in even module 1 and is mounted on first Elastic hook 106 in limit hole 103, by elastic hook 106 and wedge locating block 108, so that parity mode group 107 Rear and front end is fixed so that parity mode group 107 can not front and back overturning, and parity mode group 107 shares an elastic hook 106, It is upward in the left and right sides wall of mounting groove 101 to ensure that the consistency of the contact of press plate position between parity mode group 107 Muscle wall 102 is extended to form, muscle wall 102 move left and right parity mode group 107 can not, to realize parity mode group 107 position is fixed, so that parity mode group 107 is unbiased, ensure that the normotopia degree for the terminal that product is crimped on pcb board meets It is required that.

Although reference be made herein to the utility model is described in multiple explanatory embodiments of the utility model, still, It should be understood that those skilled in the art can be designed that a lot of other modification and implementations, these modifications and implementations It will fall within scope and spirit disclosed in the present application.More specifically, it discloses in the application, drawings and claims In range, can building block to theme combination layout and/or layout carry out a variety of variations and modifications.In addition to building block And/or outside the modification and improvement of layout progress, to those skilled in the art, other purposes also be will be apparent.

Claims (9)

1. back panel connector, it is characterised in that: it includes male end pedestal (140) and female end pedestal (100), the female end pedestal (100) it is plugged on the male end pedestal (140), not deflective parity mode group is installed on the female end pedestal (100) (107), the parity mode group (107) includes the odd module (2) being mutually close to and even module (1), is opened up on the surprise module (2) Have multiple for arrange that the odd module difference of the second cabling group (4) is walked line chamber (8), offers multiple use on the even module (1) It is walked line chamber (9) in the even module difference for arranging the first cabling group (3), the second cabling group (4) and the first cabling group (3) It include the return piece (32) of differential pair (31) and setting in the differential pair (31) side, the second of the return piece (32) connects Socket part (322) offers through slot (324), is provided with several connection bridges (323), and the connection bridge in the through slot (324) (323) through slot (324) is separated into several segments.

2. back panel connector according to claim 1, it is characterised in that: it is described surprise module difference walk line chamber (8) with it is described Even module difference walks line chamber (9) and is interspersed, and surprise module difference described in face is walked to be arranged on the even module (1) of line chamber (8) Have the first convex block (5), the first convex block (5) cooperation is walked in line chamber (8) in the odd module difference, and idol module described in face is poor It point walks and to be provided with the second convex block (6) on the odd module (2) of line chamber (9), the second convex block (6) cooperation is in even module difference It walks in line chamber (9).

3. back panel connector according to claim 2, it is characterised in that: it is three that the surprise module difference, which walks line chamber (8), And long it is divided into that the 4th difference walks line chamber (21), the 5th difference walks line chamber (22), the 6th difference walks line chamber (23), position from being short to In the 4th difference walks line chamber (21), the 5th difference walks line chamber (22), the 6th difference walk line chamber (23) two sides odd module (2) it is provided on the second convex block (6), the idol module difference walks line chamber (9) also as three, and long is divided into the from being short to One difference walks line chamber (11), the second difference walks line chamber (12), third difference walks line chamber (13), walks line chamber positioned at first difference (11), the second difference walks line chamber (12), third difference is walked and is provided with the first convex block in the even module (1) of line chamber (13) two sides (5), first difference walks line chamber (11), the second difference walks line chamber (12), third difference walks line chamber (13), the 4th difference cabling Chamber (21), the 5th difference walk line chamber (22), the 6th difference is walked in line chamber (23) at least provided with an interconnecting piece (7).

4. back panel connector according to claim 2, it is characterised in that: the back side of first convex block (5) offers First groove (51), and the cell wall thickness of first groove (51) is uniform, the back side of second convex block (6) offers second The cell wall thickness of groove (61), second groove (61) is uniform.

5. back panel connector according to claim 4, it is characterised in that: be provided with the to be staggered on idol module (1) One positioning column (41) and the second positioning column (43) offer on surprise module (2) corresponding with the first positioning column (41) Second location hole corresponding with the second positioning column (43) is offered on first positioning hole (42) and the odd module (2) (44).

6. back panel connector according to claim 1 or 5, it is characterised in that: the differential pair (31) includes the first contact (311), first connecting portion (312) and the first connection-peg (313), first contact (311) and the first connecting portion (312) One end connection, the other end of the first connecting portion (312) connect with first connection-peg (313), the return piece It (32) further include the second contact (321) and the second connection-peg (325), second contact (321) and the second connecting portion (322) one end connection, the other end of the second connecting portion (322) are connect with second connection-peg (325).

7. back panel connector according to claim 6, it is characterised in that: offer and be used on the female end pedestal (100) The mounting groove (101) of the parity mode group (107) is installed, the rear wall of the mounting groove (101) upwardly extends to form back side panel (104), it offers the first limit hole (103) on the back side panel (104), is offered on the front side wall of the mounting groove (101) Alignment is provided with wedge locating block (108) on the front side wall of second limit hole (105), the surprise module (2) and even module (1), The wedge locating block (108) is mounted in second limit hole (105), offers on the idol module (1) and is mounted on institute State the elastic hook (106) in the first limit hole (103).

8. back panel connector according to claim 7, it is characterised in that: the left and right sides wall of the mounting groove (101) to On extend to form muscle wall (102).

9. back panel connector according to claim 7, it is characterised in that: opened on the front side wall of the female end pedestal (100) Equipped with multiple slots (144), offered locating convex block (145) on the rear wall of the female end pedestal (100), the male end pedestal (140) U-type groove (141) for installing female end pedestal (100) is offered on, is arranged on the preceding inner sidewall of the U-type groove (141) Have grafting block (142), is offered locating slot (143) on the rear inner sidewall of the U-type groove (141), grafting block (142) cooperation In the corresponding slot (144) of installation, the locating convex block (145) is fitted in the locating slot (143).