Wiring terminal limiting mechanism for power semiconductor device test equipment

Abstract

The utility model relates to a binding post limiting mechanism for a power semiconductor device test device, the test device comprises a power supply jig and a bearing jig which can move relatively, a binding post is vertical, and the structure of the limiting mechanism comprises an inner support base movably installed on a jig base of the power supply jig; the inner sliding block is mounted on the inner support base in a sliding manner; the first elastic body is used for elastically connecting the inner sliding block with the inner supporting base; the inner supporting driving block is fixedly connected with the jig base, and the side face of the end makes contact with one end of the inner sliding block under the elastic force effect of the first elastic body; the power supply jig and the bearing jig move oppositely to drive the inner supporting base to move towards the jig base, then the inner supporting driving block drives the inner sliding block to move, the inner sliding block makes contact with the wiring terminal, the bearing jig moves away from the power supply jig, the inner sliding block is reset, good contact between the limiting structure and the wiring terminal is guaranteed, and deformation of the wiring terminal is avoided. And meanwhile, the device can be smoothly separated from the power supply jig.

Description

Technical Field

[0001] This utility model relates to the field of power semiconductor device testing technology, and in particular to a terminal limiting mechanism for power semiconductor device testing equipment. Background Technology

[0002] When testing power semiconductor devices (hereinafter referred to as "devices"), it is usually necessary to use a crimping method to tightly fit the device's terminals with the soft copper busbar (test terminals) to ensure stable power supply.

[0003] Most of the terminals of existing devices are horizontal terminals. There are a large number of compatible crimping mechanisms for horizontal terminals. However, there are fewer compatible crimping mechanisms for devices with vertical terminals. Traditional crimping mechanisms are mainly driven by cylinders in the horizontal and vertical directions to move the terminal relative to the flexible copper busbar in two directions, so that the two are in contact and the device is connected to the test circuit. Usually, a limit block is set on one side of the terminal. When the flexible copper busbar is crimped with the terminal, the limit block plays a role in preventing the terminal from deforming.

[0004] The fit between the aforementioned limiting block and the terminal block is unstable during the crimping process, making it difficult to avoid bending the terminal block. This can lead to difficulties in removing the device from the limiting block after testing, or the terminal block not being able to detach smoothly from the limiting block, thus hindering the automatic testing process of the device and affecting testing efficiency. Utility Model Content

[0005] In response to the shortcomings of the existing production technology, the applicant provides a terminal limiting mechanism for power semiconductor device testing equipment, thereby improving the adaptability of the testing equipment, ensuring good contact between the limiting structure and the terminal, preventing terminal deformation, protecting the device terminals, enabling the device to be reused, and allowing the device to be smoothly removed from the power supply fixture.

[0006] The technical solution adopted in this utility model is as follows:

[0007] A terminal limiting mechanism for a power semiconductor device testing equipment, the testing equipment including a power supply fixture and a support fixture that are movable relative to each other, the support fixture for placing the device, the terminal being disposed on the substrate of the device, the terminal being vertical, and the limiting mechanism comprising the following structure:

[0008] An inner support base is movably mounted on the fixture base of the power supply fixture;

[0009] The inner slider is slidably mounted on the side of the inner support base opposite to the fixture base;

[0010] A first elastic body elastically connects the inner slider to the inner support base;

[0011] The inner support drive block has one end fixedly connected to the fixture base, and the other end side contacts one end of the inner slider under the elastic force of the first elastic body.

[0012] In this process, the power supply fixture and the support fixture move towards each other, causing the inner support base to contact the support fixture. Then, the inner support base is driven to move toward the fixture base, and the inner support drive block drives the inner slider to move, causing the inner slider to contact the terminal block. The support fixture moves away from the power supply fixture, causing the inner slider to reset.

[0013] As a further improvement to the above technical solution:

[0014] A driving inclined surface is provided on one side of the end of the inner support driving block. The driving inclined surface slides in conjunction with the end of the inner slider, converting the relative displacement between the inner support base and the inner support driving block into the relative displacement between the inner slider and the inner support base.

[0015] The inner slider is provided with a guide slope that slides in cooperation with the driving slope.

[0016] Multiple guide blocks are installed on the inner support base. Adjacent guide blocks form a sliding groove with the surface of the inner support base. Sliding strips are provided on both sides of the inner slider. The sliding strips slide in cooperation with the sliding groove and restrict the inner slider to a position perpendicular to the sliding direction of the inner slider.

[0017] The limiting mechanism also includes a limiting member, one end of which is connected to the inner support base and the other end of which is connected to the fixture base, for limiting the maximum distance between the inner support base and the fixture base.

[0018] The limiting mechanism further includes a second elastic body, which is disposed between the fixture base and the inner support base, elastically connecting the fixture base and the inner support base. The second elastic body is in a compressed state and is used to provide a thrust that moves the inner support base away from the fixture base.

[0019] The inner support base is provided with a first groove, and the inner slider is provided with a second groove. The inner wall of the first groove abuts against one end of the first elastic body, and the inner wall of the second groove abuts against the other end of the first elastic body. When the inner slider slides relative to the inner support base, the first groove and the second groove move relative to each other, changing the compression amount of the first elastic body.

[0020] The inner support base is provided with a movable hole, and the middle part of the inner support drive block is located in the movable hole. When the inner support base moves relative to the fixture base, the moving direction of the inner support drive block and the inner support base is the same as the axial direction of the movable hole, and the moving direction is perpendicular to the sliding direction of the inner slider.

[0021] The power supply fixture is provided with a moving component, and a test terminal is installed on the moving component. After the inner slider contacts one side of the terminal, the moving component drives the test terminal to move toward the terminal, so that the test terminal contacts and connects with the other side of the terminal, or the moving component drives the test terminal to move away from the terminal, so that the test terminal is disconnected from the terminal.

[0022] The device has two terminals arranged opposite to each other. The inner support bases on both sides of the inner support drive block are provided with inner sliders. After the inner sliders on both sides of the inner support drive block move synchronously under the drive of the inner support drive block, they contact the two terminals respectively.

[0023] The beneficial effects of this utility model are as follows:

[0024] This utility model has a compact and reasonable structure and is easy to operate. By movably installing an inner support base on the base of the power supply fixture and fixing an inner support drive block, the relative movement between the power supply fixture and the bearing fixture is converted into the relative movement between the inner support base and the inner support drive block. This allows the inner support drive block to act on the inner slider that is slidably and elastically mounted on the inner support base, driving the inner slider to move against the elastic force and reset under the action of the elastic force. This ensures good contact between the limiting mechanism and the terminal block, provides support for the terminal block, avoids deformation of the terminal block, protects the terminal block of the device, makes the device reusable, and allows the device to smoothly detach from the power supply fixture.

[0025] In addition, this utility model also has the following advantages:

[0026] (1) The inner support base of the limiting mechanism is movably connected to the fixture base by the first limiting member and the second elastic body, so that the inner support base can move smoothly during the relative movement of the bearing fixture and the power supply fixture, thereby realizing the relative movement of the bearing fixture and the power supply fixture to drive the inner slider to move.

[0027] (2) By providing a first groove on the inner support base and a second groove on the inner slider, the first groove and the second groove form an installation cavity for installing the first elastic body. The installation cavity is located between the inner slider and the inner support base, and under the limiting action of the inner support drive block, the compression deformation of the first elastic body is maintained. While realizing the function of the limiting mechanism, the overall structural size of the limiting mechanism is reduced, making the limiting mechanism simple in shape and easy to adapt to the device. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the structure of this utility model.

[0029] Figure 2 This is a schematic diagram of the structure of the present invention (another state).

[0030] Figure 3 This is a schematic diagram of the limiting mechanism of this utility model.

[0031] Figure 4 This is a schematic diagram of the limiting mechanism of this utility model (from another perspective).

[0032] Figure 5 This is an exploded view of the limiting mechanism of this utility model.

[0033] Figure 6a This is a schematic diagram of the action of the limiting mechanism of this utility model, in which the inner support drive block pushes the inner slider to move, thereby compressing the first elastic body.

[0034] Figure 6b This is a schematic diagram of the movement of the slider in the limiting mechanism of this utility model resetting under the action of the first elastic body.

[0035] Figure 7 This is a schematic diagram of the internal slider of this utility model.

[0036] Figure 8 This is a schematic diagram of the structure of the device of this utility model.

[0037] in:

[0038] 1. Power supply fixture;

[0039] 11. Fixture base;

[0040] 12. Test terminals;

[0041] 13. Limiting mechanism;

[0042] 131. Inner slider; 1311. Sliding bar; 1312. Second groove; 1313. Guide slope;

[0043] 132. Internal support drive block; 1321. Drive inclined plane;

[0044] 133. Inner support base; 1331. Pressure block; 1332. Guide block; 1333. First groove;

[0045] 134. Second elastic body; 136. Limiting element; 135. Guide post; 137. First elastic body; 138. Movable hole;

[0046] 15. Moving components;

[0047] 2. Support fixture;

[0048] 3. Components; 31. Terminal blocks; 32. Reference surface; 33. Substrate. Detailed Implementation

[0049] The specific embodiments of this utility model are described below with reference to the accompanying drawings.

[0050] like Figures 1-3 As shown in the figure, an embodiment of this application provides a terminal limiting mechanism for a power semiconductor device testing equipment. The testing equipment includes a power supply fixture 1 and a support fixture 2 that can move relative to each other. The support fixture 2 is used to place a device 3. A terminal 31 is provided on the substrate 33 of the device 3. The terminal 31 is vertical. The limiting mechanism 13 includes an inner support base 133, an inner slider 131, a first elastic body 137, and an inner support drive block 132.

[0051] The inner support base 133 is movably mounted on the fixture base 11 of the power supply fixture 1;

[0052] The inner slider 131 is slidably mounted on the side of the inner support base 133 that is away from the fixture base 11;

[0053] The first elastic body 137 elastically connects the inner slider 131 to the inner support base 133.

[0054] The inner support drive block 132 is fixedly connected to the fixture base 11 at one end, and the other end side contacts one end of the inner slider 131 under the elastic force of the first elastic body 137.

[0055] In this process, the power supply fixture 1 and the support fixture 2 move towards each other, causing the inner support base 133 to contact the support fixture 2. Then, the inner support base 133 is driven to move toward the fixture base 11, and the inner support drive block 132 drives the inner slider 131 to move, so that the inner slider 131 contacts the terminal 31. The support fixture 2 moves away from the power supply fixture 1, so that the inner slider 131 is reset.

[0056] For example, the power supply fixture 1 is provided with a moving component 15, on which a test terminal 12 is mounted. After the inner slider 131 contacts one side of the wiring terminal 31, the moving component 15 drives the test terminal 12 to move towards the wiring terminal 31, so that the test terminal 12 contacts and connects with the other side of the wiring terminal 31, or the moving component 15 drives the test terminal 12 away from the wiring terminal 31, so that the test terminal 12 is disconnected from the wiring terminal 31. The test terminal 12 is movably mounted on the fixture base 11, and can be driven to move by a cylinder mounted on the fixture base 11 to achieve contact connection and disconnection between the test terminal 12 and the wiring terminal 31. After the wiring terminal 31 of the device 3 is connected to the test terminal 12, the device 3 can be subjected to reactive power aging test or other tests.

[0057] Specifically, during the relative movement of the power supply fixture 1 and the support fixture 2, the inner slider 131 in the limiting mechanism 13 moves; after the inner slider 131 contacts the terminal 31, the test terminal 12 is then pressed onto the terminal 31. When the test terminal 12 is removed from the terminal 31, the inner slider 131 resets, ensuring that the terminal 31 can be well supported during the pressing process and avoiding deformation by the test terminal 12. At the same time, after the connection between the test circuit and the terminal 31 is released and the inner slider 131 moves away from the terminal 31, the power supply fixture 1 moves away from the support fixture 2, allowing the device 3 to smoothly detach from the power supply fixture 1.

[0058] like Figure 1 , Figure 8 As shown, under normal circumstances, the terminal 31 is in the form of a sheet. The terminal 31 is perpendicular to the reference surface 32 of the substrate 33 and is located at the edge of the substrate 33. The device 3 has multiple terminals 31, which are arranged side by side at the edge of the reference surface 32.

[0059] In one exemplary embodiment, such as Figure 8 As shown, the multiple terminals 31 include one AC power terminal and three DC power terminals. The three DC power terminals are arranged side by side. Generally, when testing device 3, multiple devices 3 can be placed side by side to improve testing efficiency. The AC power terminals and DC power terminals of device 3 are arranged opposite each other, that is, the terminals 31 of multiple devices 3 form two rows. The limiting mechanism 13 corresponds to the reference surface 32 between the two rows of terminals 31. The adaptable inner slider 131 and the test terminals 12 are two sets, wherein the test terminals 12 can be copper busbars.

[0060] The crimping mechanism of this embodiment is particularly advantageous when the terminal blocks 31 are arranged in two rows. For example, as shown... Figure 1 As shown in Figure 6, the device 3 has two terminals 31 arranged opposite to each other. Inner sliders 131 are provided on the inner support bases 133 on both sides of the inner support drive block 132. The inner sliders 131 on both sides of the inner support drive block 132 move synchronously under the drive of the inner support drive block 132 and contact the two terminals 31 respectively. By using the relative movement of the power supply fixture 1 and the bearing fixture 2 to drive the contact and disengagement of the inner sliders 131 with the terminals 31 in the limiting mechanism 13, it is possible to prevent the device 3 from being hung on the limiting structure (limiting mechanism 13) after the terminals 31 deform, thus allowing the device 3 to smoothly detach from the power supply fixture 1.

[0061] For example, a power supply device is provided on the fixture base 11, and the power supply device is electrically connected to the test terminal 12. The power supply fixture 1 is located above the support fixture 2. The support fixture 2 is driven to move up and down by a drive mechanism, which can be a cylinder. The reference surface 32 of the substrate 33 faces the support fixture 2, and the moving direction of the support fixture 2 is perpendicular to the thickness direction of the terminal 31.

[0062] The working state of the crimping mechanism in the above embodiment is as follows:

[0063] like Figure 1 And as shown in Figure 6b, this is the state when the supporting fixture 2 is not in contact with the inner support base 133;

[0064] After the inner support base 133 contacts the supporting fixture 2, as the supporting fixture 2 moves toward the fixture base 11, the inner support base 133 moves relative to the inner support drive block 132. The inner support drive block 132 pushes the inner slider 131 to move, compressing the first elastic body 137, until the fixture base 11 contacts the inner support base 133, at which point the other end of the inner slider 131 contacts the terminal block 31. Figure 2 And as shown in Figure 6a;

[0065] When the supporting fixture 2 moves away from the fixture base 11 in the reverse direction, the inner support base 133 moves away from the fixture base 11, the inner support drive block 132 moves in the opposite direction relative to the inner support base 133, the first elastic body 137 extends, that is, the inner slider 131 returns to its original position under the action of the first elastic body 137, the inner slider 131 moves away from the terminal 31, and the limiting mechanism 13 returns to its original position. Figure 1 And the state shown in Figure 6b.

[0066] For example, the first elastic body 137 can be a spring in a compressed state, which keeps in contact with the inner slider 131 and the inner support drive block 132 by elastic force; a pressure block 1331 is installed on the inner support base 133, and the inner support base 133 and the bearing fixture 2 are made in contact by the pressure block 1331.

[0067] An inner support base 133 is movably installed on the fixture base 11 of the power supply fixture 1, and an inner support drive block 132 is fixedly installed. The relative movement between the power supply fixture 1 and the bearing fixture 2 is converted into the relative movement between the inner support base 133 and the inner support drive block 132. This causes the inner support drive block 132 to interact with the inner slider 131, which is slidably and elastically mounted on the inner support base 133. This drives the inner slider 131 to move against the elastic force and to reset under the action of the elastic force. This ensures good contact between the limiting mechanism 13 and the terminal block 31, provides support for the terminal block 31, prevents the terminal block 31 from deforming, protects the terminal block 31 of the device 3, makes the device 3 reusable, and allows the device 3 to smoothly detach from the power supply fixture 1.

[0068] In one exemplary embodiment, such as Figure 5 As shown in Figure 6, a driving inclined surface 1321 is provided on one side of the end of the inner support driving block 132. The driving inclined surface 1321 is slidably engaged with the end of the inner slider 131, so as to convert the relative displacement between the inner support base 133 and the inner support driving block 132 into the relative displacement between the inner slider 131 and the inner support base 133.

[0069] In one exemplary embodiment, such as Figure 5 , Figure 7 As shown, the inner slider 131 is provided with a guide slope 1313 that slides in cooperation with the driving slope 1321. This makes the process of the first driving slope 1321 pushing the inner slider 131 smoother.

[0070] In one exemplary embodiment, such as Figure 5 , Figure 7 As shown, multiple guide blocks 1332 are installed on the inner support base 133. Adjacent guide blocks 1332 form a sliding groove with the surface of the inner support base 133. Slide strips 1311 are provided on both sides of the inner slider 131. The slide strips 1311 slide with the sliding groove and limit the inner slider 131 to a position perpendicular to the sliding direction of the inner slider 131.

[0071] In another exemplary embodiment, such as Figure 3 As shown in Figure 6, the limiting mechanism 13 also includes a limiting member 136. One end of the limiting member 136 is connected to the inner support base 133, and the other end of the limiting member 136 is connected to the fixture base 11, which is used to limit the maximum distance between the inner support base 133 and the fixture base 11.

[0072] In the previous exemplary embodiment, such as Figure 3 As shown in Figure 6, the limiting mechanism 13 also includes a second elastic body 134, which is disposed between the fixture base 11 and the inner support base 133, elastically connecting the fixture base 11 and the inner support base 133. The second elastic body 134 is in a compressed state and is used to provide a thrust that moves the inner support base 133 away from the fixture base 11.

[0073] Specifically, the second elastic body 134 can be a spring, and the first limiting member 136 is a first screw installed on the inner support base 133, with the head of the first screw engaging with a first countersunk hole located on the fixture base 11.

[0074] To ensure the stability of the inner support base 133 relative to the jig base 11 in the direction of movement, a guide post 135 is installed on the inner support base 133, and the guide post 135 slides in cooperation with the jig base 11.

[0075] The inner support base 133 of the limiting mechanism 13 is movably connected to the fixture base 11 by the first limiting member 136 and the second elastic body 134, so that the inner support base 133 can move smoothly during the relative movement of the bearing fixture 2 and the power supply fixture 1, thereby driving the inner slider 131 to move.

[0076] In the above embodiments, the first elastic body 137 can be installed in various ways, such as by maintaining contact between the inner slider 131 and the inner support drive block 132 through elastic force. However, due to the structure of the device 3, the structural space arrangement of the limiting mechanism 13 is limited. In order to make the limiting mechanism 13 simple in shape and occupy less space, a solution is provided in another exemplary embodiment, as shown in Figure 6. Figure 7 As shown, the inner support base 133 of this embodiment is provided with a first groove 1333, and the inner slider 131 is provided with a second groove 1312. The inner wall of the first groove 1333 abuts against one end of the first elastic body 137, and the inner wall of the second groove 1312 abuts against the other end of the first elastic body 137. When the inner slider 131 slides relative to the inner support base 133, the first groove 1333 and the second groove 1312 move relative to each other, changing the compression amount of the first elastic body 137.

[0077] By providing a first groove 1333 on the inner support base 133 and a second groove 1312 on the inner slider 131, the first groove 1333 and the second groove 1312 form a mounting cavity for mounting the first elastic body 137. The mounting cavity is located between the inner slider 131 and the inner support base 133, and under the limiting action of the inner support drive block 132, the compression deformation of the first elastic body 137 is maintained. While realizing the function of the limiting mechanism 13, the overall structural size of the limiting mechanism 13 is reduced, making the limiting mechanism 13 simple in appearance and easy to adapt to the device 3.

[0078] In another exemplary embodiment, such as Figure 5 As shown, the inner support base 133 is provided with a movable hole 138, and the middle part of the inner support drive block 132 is located in the movable hole 138. When the inner support base 133 moves relative to the fixture base 11, the moving direction of the inner support drive block 132 and the inner support base 133 is the same as the axial direction of the movable hole 138, and the moving direction is perpendicular to the sliding direction of the inner slider 131, which simplifies the overall structure of the limiting mechanism 13.

[0079] The above description is an explanation of the present utility model and not a limitation thereof. The scope of the present utility model is defined by the claims. Within the protection scope of the present utility model, any form of modification may be made.

Claims

1. A terminal limiting mechanism for a power semiconductor device testing equipment, characterized in that: The testing equipment includes a power supply fixture (1) and a support fixture (2) that can move relative to each other. The support fixture (2) is used to place the device (3). The terminal block (31) is provided on the substrate (33) of the device (3). The terminal block (31) is vertical. The structure of the limiting mechanism (13) includes: The inner support base (133) is movably mounted on the fixture base (11) of the power supply fixture (1); The inner slider (131) is slidably mounted on the side of the inner support base (133) opposite to the fixture base (11); The first elastic body (137) elastically connects the inner slider (131) to the inner support base (133); The inner support drive block (132) is fixedly connected at one end to the fixture base (11), and the other end of the side contacts one end of the inner slider (131) under the elastic force of the first elastic body (137). In this process, the power supply fixture (1) and the support fixture (2) move towards each other, causing the inner support base (133) to contact the support fixture (2). Then, the inner support base (133) is driven to move toward the fixture base (11), and the inner support drive block (132) drives the inner slider (131) to move, so that the inner slider (131) contacts the terminal (31). The support fixture (2) moves away from the power supply fixture (1), so that the inner slider (131) is reset.

2. The terminal limiting mechanism for power semiconductor device testing equipment as described in claim 1, characterized in that: The inner support drive block (132) has a drive ramp (1321) on one side of its end. The drive ramp (1321) slides with the end of the inner slider (131) to convert the relative displacement between the inner support base (133) and the inner support drive block (132) into the relative displacement between the inner slider (131) and the inner support base (133).

3. The terminal limiting mechanism for power semiconductor device testing equipment as described in claim 2, characterized in that: The inner slider (131) is provided with a guide slope (1313) that slides in cooperation with the driving slope (1321).

4. The terminal limiting mechanism for power semiconductor device testing equipment as described in claim 2, characterized in that: Multiple guide blocks (1332) are installed on the inner support base (133). Adjacent guide blocks (1332) form a sliding groove with the surface of the inner support base (133). Slide strips (1311) are provided on both sides of the inner slider (131). The slide strips (1311) slide with the sliding groove and restrict the inner slider (131) to a position perpendicular to the sliding direction of the inner slider (131).

5. The terminal limiting mechanism for power semiconductor device testing equipment as described in claim 1, characterized in that: The limiting mechanism (13) further includes a limiting member (136), one end of which is connected to the inner support base (133) and the other end of which is connected to the fixture base (11), for limiting the maximum distance between the inner support base (133) and the fixture base (11).

6. The terminal limiting mechanism for power semiconductor device testing equipment as described in claim 5, characterized in that: The limiting mechanism (13) further includes a second elastic body (134), which is disposed between the jig base (11) and the inner support base (133) to elastically connect the jig base (11) and the inner support base (133). The second elastic body (134) is in a compressed state and is used to provide a thrust that moves the inner support base (133) away from the jig base (11).

7. The terminal limiting mechanism for power semiconductor device testing equipment as described in claim 1, characterized in that: The inner support base (133) is provided with a first groove (1333), and the inner slider (131) is provided with a second groove (1312). The inner wall of the first groove (1333) abuts against one end of the first elastic body (137), and the inner wall of the second groove (1312) abuts against the other end of the first elastic body (137). When the inner slider (131) slides relative to the inner support base (133), the first groove (1333) and the second groove (1312) move relative to each other, changing the compression of the first elastic body (137).

8. The terminal limiting mechanism for power semiconductor device testing equipment as described in claim 1, characterized in that: The inner support base (133) is provided with a movable hole (138). The middle part of the inner support drive block (132) is located in the movable hole (138). When the inner support base (133) moves relative to the fixture base (11), the moving direction of the inner support drive block (132) and the inner support base (133) is the same as the axial direction of the movable hole (138), and the moving direction is perpendicular to the sliding direction of the inner slider (131).

9. The terminal limiting mechanism for power semiconductor device testing equipment as described in claim 1, characterized in that: The power supply fixture (1) is provided with a moving component (15), and a test terminal (12) is installed on the moving component (15). After the inner slider (131) contacts one side of the wiring terminal (31), the moving component (15) drives the test terminal (12) to move toward the wiring terminal (31), so that the test terminal (12) contacts and connects with the other side of the wiring terminal (31), or the moving component (15) drives the test terminal (12) to move away from the wiring terminal (31), so that the test terminal (12) is disconnected from the wiring terminal (31).

10. The terminal limiting mechanism for a power semiconductor device testing equipment as described in any one of claims 1-9, characterized in that: The device (3) has two terminals (31) arranged opposite to each other. The inner support base (133) on both sides of the inner support drive block (132) is provided with inner sliders (131). After the inner sliders (131) on both sides of the inner support drive block (132) move synchronously under the drive of the inner support drive block (132), they contact the two terminals (31) respectively.

Images