Connector convenient to assemble and capable of enhancing terminal positioning

Abstract

The invention belongs to the technical field of electric connectors, and particularly relates to an automobile connector adopting a terminal secondary locking technology, in particular to a connector convenient to assemble and capable of enhancing terminal positioning. The device comprises a TPA assembly, a sheath assembly and a terminal assembly, relative positions between the TPA assembly and the sheath assembly comprise a pre-locking position and a final locking position, and the TPA assembly comprises a TPA body and at least one cantilever beam; the sheath assembly comprises: a sheath body; a clamping groove, a terminal hole, a second limiting part and a first limiting part; when the TPA assembly is located at the pre-locking position, the second clamping piece abuts against the second limiting part to prevent the TPA assembly from moving towards the final locking position, and the first clamping piece abuts against the first limiting part to prevent the cantilever beam from being separated from the clamping groove. In the pre-locking position, the second clamping piece is matched with the second limiting part, strong resistance is provided, and the TPA is prevented from accidentally sliding into the final locking position. In the final locking position, the first clamping piece of the TPA is in interference fit with the first surface of the terminal, so that the positioning stability is enhanced.

Description

Technical Field

[0001] This invention belongs to the field of electrical connector technology, and particularly relates to automotive connectors with secondary terminal locking technology, specifically to a connector that facilitates assembly and enhances terminal positioning. Background Technology

[0002] The Terminal Position Assurance (TPA) is a critical safety component in automotive connectors. Its main function is to lock the terminal in a secondary locking position after it has been correctly inserted into the connector housing's terminal hole. This prevents the terminal from coming loose due to vibration, pulling, or other reasons, thus ensuring the reliability of the electrical connection.

[0003] Existing TPA structures typically employ a pre-assembly mode, where the TPA is pre-installed onto the sheath via its locking points, placing it in a "pre-locked" position. Once the terminal is correctly inserted into the sheath by the wiring harness manufacturer, the TPA is then fully pressed from the "pre-locked" position to the "final lock" position. At this point, the locking portion of the TPA engages with the corresponding structure of the terminal, preventing the terminal from retracting. For example, Patent Document 1 discloses a connector with a sliding terminal position guarantee. When the terminal position guarantee is in the pre-locked position, each locking protrusion engages with the lower surface of one of the locking grooves to prevent the terminal position guarantee from moving towards the pre-insertion position.

[0004] However, in order to ensure that the TPA will not lock prematurely due to accidental collisions during the transportation and handling of the connector in its pre-assembled state, the fit between its pre-assembly locking point and the sheath is usually designed with a large interference. This means that when performing the final locking operation at the terminal factory, a lot of pressing force is required to press the TPA into place. Excessive locking force not only increases the workload of workers and affects assembly efficiency, but also poses a risk of damaging the TPA or sheath structure.

[0005] Patent document 1: Chinese invention patent with publication number CN111446572A and publication date of 2020-07-24. Summary of the Invention

[0006] The purpose of this invention is to provide a connector that facilitates assembly and enhances terminal positioning, so that the TPA can be easily installed into the sheath after the terminals are correctly inserted.

[0007] The technical solution adopted by the present invention to solve the above problems is: a connector that facilitates assembly and enhances terminal positioning, comprising: a TPA assembly, a sheath assembly, and a terminal assembly. The relative position between the TPA assembly and the sheath assembly includes a pre-locked position and a final-locked position. The TPA assembly includes: a TPA body; at least one cantilever beam, the cantilever beam including a fixed end and a free end, the fixed end being connected to the TPA body, and the free end extending to the locking direction of the TPA body; a first locking member disposed at or near the free end of the cantilever beam; and a second locking member disposed on the cantilever beam and further away from the free end relative to the first locking member.

[0008] The sheath assembly includes: a sheath body; a slot disposed on the sheath body, wherein at least part of the cantilever beam is received within the slot; a terminal hole for mounting a terminal assembly; a second limiting portion and a first limiting portion;

[0009] When the TPA assembly is in the pre-locked position, the second locking member abuts against the second limiting part to prevent the TPA assembly from moving to the final locked position, and the first locking member abuts against the first limiting part to prevent the cantilever beam from disengaging from the slot.

[0010] A further preferred technical solution is that the contact surface between the terminal assembly and the first locking member is the first surface of the terminal. When the terminal assembly is installed into the terminal hole and the TPA assembly is in the final locked position, the first locking member and the first surface of the terminal are interference-fitted.

[0011] A further preferred technical solution is that the contact surface between the first surface of the terminal and the first card is an interference plane or has several protrusions.

[0012] A further preferred technical solution is that the sheath assembly also includes a third limiting part, the terminal assembly includes a second terminal surface, and a terminal engaging surface is provided in the vertical direction on the second terminal surface. When the terminal assembly is installed into the terminal hole, the third limiting part abuts against the terminal engaging surface to prevent the terminal from dislodging from the terminal hole.

[0013] A further preferred technical solution is that when the terminal assembly is installed into the terminal hole and the TPA assembly is in the final locked position, the terminal assembly is also biased towards the third limiting part to increase the contact area between the terminal engagement surface and the third limiting part.

[0014] A further preferred technical solution is that the first and second locking components are staggered in the locking direction.

[0015] A further preferred technical solution is that the sheath assembly further includes a fourth limiting part and a fifth limiting part, which are located on both sides inside the terminal hole and are used to abut against the first surface of the terminal and the second surface of the terminal, so as to limit the normal direction of the terminal assembly in the insertion direction.

[0016] A further preferred technical solution is that when the terminal assembly is inserted into the terminal hole, the first surface of the terminal presses against the first clip, causing the cantilever beam to undergo elastic deformation.

[0017] A further preferred technical solution is that the sheath assembly also includes a guide structure, which is located in the slot and adjacent to the second limiting part. When the cantilever beam undergoes elastic deformation, the guide structure cooperates with the second locking member to provide guidance and reduce movement resistance.

[0018] A further preferred technical solution is that the guide structure is a rounded corner or C-corner structure.

[0019] In summary, the present invention has the following advantages:

[0020] 1. In the pre-locked position, the second locking member cooperates with the second limiting part to provide strong resistance, effectively preventing the TPA from accidentally sliding into the final locked position due to vibration or collision during transportation and handling. Simultaneously, the first locking member cooperates with the first limiting part to prevent the TPA from falling off the protective sleeve.

[0021] 2. The present invention utilizes the force during terminal insertion to pre-release the TPA's pre-locking restriction, thereby significantly reducing the final locking operation force and facilitating assembly.

[0022] 3. In the final locking position, the first locking member of the TPA forms an interference fit with the first surface of the terminal, which effectively suppresses the radial wobble of the terminal and enhances positioning stability.

[0023] 4. The lateral force applied by the TPA of the present invention pushes the terminal as a whole toward the third limiting part on the side of the sheath, further enhancing the terminal's anti-removal capability.

[0024] 5. When the cantilever beam of the present invention deforms due to the insertion of the terminal, the guide structure provides smooth guidance for the movement of the second locking piece, so that it can slide smoothly off the second limiting part, avoiding hard scratches and excessive resistance caused by the right angle edge. Attached Figure Description

[0025] The invention will be further described below with reference to the accompanying drawings:

[0026] Figure 1 This is a schematic diagram of the exploded structure of the connector.

[0027] Figure 2 This is a schematic diagram of the TPA component.

[0028] Figure 3 This is a cross-sectional schematic diagram of the sheath assembly.

[0029] Figure 4 This is a cross-sectional schematic diagram of the TPA component.

[0030] Figure 5This is a schematic diagram of the terminal assembly.

[0031] Figure 6 This is a schematic diagram of the TPA component in the pre-locked position.

[0032] Figure 7 This is a schematic diagram of the TPA component in the final lock position.

[0033] In the attached diagram, the components represented by each number are as follows: cantilever beam 1, first locking member 2, second locking member 3, locking slot 4, upper end face of first locking member 5, first limiting part 6, lower end face of second locking member 7, second limiting part 8, terminal hole 9, fourth limiting part 10, fifth limiting part 11, first surface of terminal 12, guide structure 13, third limiting part 15, second surface of terminal 16, terminal assembly 97, TPA assembly 98, and sheath assembly 99. Detailed Implementation

[0034] The present invention will be specifically illustrated below with reference to embodiments:

[0035] This specific embodiment is merely an explanation of the present invention and is not intended to limit the invention. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they are within the scope of the claims of the present invention.

[0036] Example:

[0037] refer to Figures 1-7 A connector for easy assembly and enhanced terminal positioning, comprising a TPA assembly 98, a sheath assembly 99, and a terminal assembly 97. The relative positions of the TPA assembly 98 and the sheath assembly 99 include a pre-locked position and a final-locked position. The TPA assembly 98 includes:

[0038] TPA ontology;

[0039] At least one cantilever beam 1, the cantilever beam 1 includes a fixed end and a free end, the fixed end is connected to the TPA body, and the free end extends to the locking direction of the TPA body;

[0040] The first fastener 2 is located at or near the free end of the cantilever beam 1;

[0041] The second clamp 3 is mounted on the cantilever beam 1 and is further away from the free end than the first clamp 2;

[0042] Sheath assembly 99 includes:

[0043] Sheath body;

[0044] The slot 4 is provided on the sheath body, and the cantilever beam 1 is at least partially accommodated in the slot 4;

[0045] Terminal hole 9 is used to install terminal assembly 97;

[0046] The second limiting part 8 and the first limiting part 6; when the TPA assembly 98 is in the pre-locked position, the second locking part 3 abuts against the second limiting part 8 to prevent the TPA assembly 98 from moving to the final locking position, and the first locking part 2 abuts against the first limiting part 6 to prevent the cantilever beam 1 from disengaging from the slot 4.

[0047] In this context, "pre-installed position" specifically refers to the relative positions of the components when the connector is shipped from the factory and before the terminal assembly 97 is inserted; "final lock position" specifically refers to the relative positions of the components after the terminal assembly 97 is inserted and the TPA assembly 98 locks; and "locking direction" specifically refers to the direction in which the TPA assembly 98 moves from the "pre-installed position" to the "final lock position." The terminal assembly 97 is a common type of terminal in the prior art, used to establish reliable electrical connections with other circuit components. The TPA body is the main framework of the TPA; for simplicity, in this embodiment, TPA is used to refer to the TPA body.

[0048] refer to Figure 2 The cantilever beam 1 is an elastic structure similar to a diving board. Its fixed end is attached to the TPA, while the other end, a free end, is suspended and can deform to a small extent. The first locking piece 2 is located near the free end of the cantilever beam 1 and engages with the sheath in the pre-locked position to prevent the TPA from detaching from the sheath. The second locking piece 3 is located on the cantilever beam, but closer to the fixed end than the first locking piece 2. Its core function is to lock the sheath in the pre-locked position, preventing the TPA from being accidentally pressed down and locking, thus solving the transportation safety issue. When the terminal assembly 97 is correctly installed, it will cause a small deformation of the cantilever beam 1. At this time, the second locking piece 3 can be released from its locking state, or easily released, solving the problem of inconvenience for workers and affecting assembly efficiency.

[0049] The sheath body is the basic structure of the sheath. Several slots 4 are provided on the sheath body facing the TPA component 98. The slots 4 are used to accommodate the cantilever beam 1 and allow it to move inside. The second limiting part 8 and the first limiting part 6 are provided in the slots 4 or near the slot opening and are used to limit the steps, blocks or slots of the second locking member 3 and the first locking member 2, respectively.

[0050] refer to Figure 4The first locking component 2 has an upper end face 5, and the second locking component 3 has a lower end face 7. "The second locking component 3 abuts against the second limiting part 8" actually means that the lower end face 7 of the second locking component abuts against the second limiting part 8, and "The first locking component 2 abuts against the first limiting part 6" actually means that the upper end face 5 of the first locking component abuts against the first limiting part 6. Specifically, the lower end face 7 of the second locking component 3 abuts against the second limiting part 8, meaning that in the pre-locked position, the second locking component 3 on the cantilever beam abuts against the second limiting part 8 on the sheath, preventing the TPA assembly 98 from moving to the final locked position and ensuring that it will not accidentally lock during transportation. "The first locking component 2 abuts against the first limiting part 6" specifically means that, at the same time, the first locking component 2 at the free end of the cantilever beam 1 also hooks onto the second stop 6 on the sheath, thus preventing the TPA assembly 98 from falling off the sheath and ensuring the stability of the pre-installed state.

[0051] Typically, to avoid difficulty in inserting terminals, a necessary gap is usually reserved between the terminal and the inner wall of the sheath. However, this results in a certain radial wobble inside the sheath after the terminal is correctly inserted. The wobble of the terminal will affect the stability of the electrical connection. In the harsh automotive vibration environment, it may cause safety hazards such as increased contact resistance, electrical sparks, or even short circuits.

[0052] Furthermore, the contact surface between the terminal assembly and the first locking member 2 is the first terminal surface 12. When the terminal assembly 97 is installed into the terminal hole 9 and the TPA assembly 98 is in the final locked position, the first locking member 2 and the first terminal surface 12 are interference-fitted.

[0053] The first surface 12 of the terminal is a functional surface that interacts with the first locking member 2 of the TPA assembly 98. When the terminal is correctly inserted into the terminal hole 9 of the sheath, the tail of the terminal contacts and presses against the first locking member 2, which is in a pre-locked position. This pressing force secures the terminal in the terminal hole 9, thus enhancing terminal positioning. (Reference) Figure 6 The part where the terminal abuts against the first card 2 is actually the side 14 of the first card.

[0054] Furthermore, the contact surface between the first surface 12 of the terminal and the first clip 2 is an interference plane or has several protrusions.

[0055] The protrusions further enhance the friction between the first clip 2 and the first surface 12 of the terminal, thereby further improving the terminal positioning effect.

[0056] Furthermore, the sheath assembly 99 also includes a third limiting part 15, and the terminal assembly 97 includes a terminal second surface 16, on which a terminal engaging surface is provided in the vertical direction. When the terminal assembly 97 is installed into the terminal hole 9, the third limiting part 15 abuts against the terminal engaging surface to prevent the terminal from dislodging from the terminal hole 9.

[0057] The terminal engaging surface and the third limiting part on the sheath form a mechanical interlock, providing the most direct axial locking function to prevent the terminal from retracting. (Reference) Figure 7 The third limiting part 15 is in the form of a hook. When the terminal is correctly inserted into the terminal hole 9 of the sheath, the engaging surface on the terminal engages with the elastic hook inside the sheath. When a force attempts to pull the terminal out from the rear, the hook of the sheath will firmly hook the engaging surface of the terminal, thereby preventing the terminal from accidentally detaching from the terminal hole.

[0058] Furthermore, when the terminal assembly 97 is installed into the terminal hole 9 and the TPA assembly 98 is in the final locked position, the terminal assembly 97 is also biased toward the third limiting part 15 to increase the contact area between the terminal engagement surface and the third limiting part 15.

[0059] Specifically, "biasing the terminal towards the third limiting part 15" means that the interference fit between the first locking member 2 and the first surface 12 of the terminal generates a force that pushes the entire terminal towards the third limiting part 15 on the other side of the sheath. Under the continuous lateral pushing force applied by the first locking member 2, the terminal is firmly pressed onto the third limiting part 15, so that the terminal engaging surface and the mating surface of the third limiting part 15 achieve maximum and stable surface contact.

[0060] Furthermore, the first locking element 2 and the second locking element 3 are staggered in the locking direction.

[0061] The term "misalignment" means that the first locking piece 2 and the second locking piece 3 are not on the same straight line in the locking direction. This arrangement ensures that the cantilever beam 1 has two support points on the left and right sides in the vertical direction of the locking direction, thus preventing the cantilever beam 1 from tilting.

[0062] Furthermore, the sheath assembly 99 also includes a fourth limiting part 10 and a fifth limiting part 11, which are located on both sides inside the terminal hole and are used to abut against the first surface 12 and the second surface 16 of the terminal, respectively, so that the terminal assembly 97 is normally limited in the insertion direction.

[0063] The "normal limit" refers to a plane perpendicular to the insertion direction of the terminal. The function of the "normal limit" is to prevent the terminal from laterally wobbling within the terminal hole 9 of the sheath. The fourth and fifth limit portions of the sheath define precise width and position. The terminal is restricted by this width during insertion, ensuring that the terminal enters in the correct position and orientation.

[0064] Furthermore, when the terminal assembly 97 is inserted into the terminal hole 9, the first surface 12 of the terminal presses against the first clip 2, causing the cantilever beam 1 to undergo elastic deformation.

[0065] Before the terminal is fully inserted, the TPA assembly 98 is in a stable pre-locked position. When the first surface 12 of the terminal presses against the first locking piece 2, it indicates that the terminal has been inserted to a specific depth. The first surface 12 of the terminal at its tail will contact the first locking piece 2 at the free end of the cantilever beam 1 and apply pressure. This pressing force acts on the free end of the cantilever beam 1. Since the cantilever beam 1 is an elastic structure, this force will force its free end to displace, resulting in elastic bending deformation of the entire beam. This deformation will simultaneously cause the second locking piece 3, located in the middle of the cantilever beam, to move. The displacement of the second locking piece 3 causes it to disengage from the first limiting part 8 of the sheath, thereby releasing the restriction on the movement of the TPA assembly 98 towards the final locked position. This means that when pressing the TPA subsequently, the operator only needs to overcome a small resistance instead of a large locking interference force, greatly reducing the final locking operation force and facilitating assembly.

[0066] Furthermore, the sheath assembly 99 also includes a guide structure 13, which is located in the slot and adjacent to the second limiting part 8. When the cantilever beam 1 undergoes elastic deformation, the guide structure cooperates with the second locking member 3 to provide guidance and reduce movement resistance.

[0067] The guide structure 13 is typically an inclined plane. When the terminal presses against the first locking member 2, causing the cantilever beam 1 to deform, the second locking member 3 needs to disengage from the end face of the first limiting part 8 and move downwards. Without the guide structure 13, the second locking member 3 would rub and scrape against the right-angled edge of the first limiting part 8 in a purely vertical direction, resulting in significant resistance to movement. The guide structure 13 ensures reduced frictional resistance during the movement of the second locking member 3, making the deformation of the cantilever beam 1 and the subsequent locking operation of the TPA easier, further enhancing the ease of assembly.

[0068] Furthermore, the guide structure is a rounded corner or C-corner structure.

[0069] In summary, the specific installation and usage methods for connectors that facilitate assembly and enhance terminal positioning are as follows:

[0070] Pre-installed state: TPA assembly 98 is mounted on sheath assembly 99 and is in the "pre-locked position". The second latch 3 on the cantilever beam 1 abuts against the second limiting part 8 of the sheath, preventing TPA assembly 98 from being accidentally pressed into the final locked position. The first latch 2 at the free end of the cantilever beam 1 abuts against the first limiting part 6 of the sheath, preventing TPA assembly 98 from falling off the sheath and maintaining the integrity of the pre-installed state.

[0071] Terminal Insertion and Unlocking: Correctly insert the terminal into the terminal hole 9 of the sheath until it is fully in place. When the terminal is fully inserted, the first surface 12 of the terminal at its tail end presses against the first locking piece 2 at the free end of the cantilever beam 1. This pressing force forces the cantilever beam 1 to undergo elastic deformation. The deformation of the cantilever beam 1 causes the second locking piece 3 on it to move, disengaging it from the second limiting part 8. The guide structure 13 on the sheath guides the second locking piece 3 to move smoothly, significantly reducing the resistance of subsequent locking operations.

[0072] Final Lock Position: After the terminal is inserted into place, a small force is used to push the TPA assembly 98 completely from the "pre-lock position" to the "final lock position". In the final lock position, the first locking member 2 forms an interference fit with the first surface 12 of the terminal, generating a continuous lateral thrust that firmly presses the terminal in place, preventing it from laterally wobbling within the terminal hole. This lateral thrust simultaneously pushes the entire terminal towards the third limiting part 15 on the other side of the sheath, ensuring maximum tight contact between the terminal engagement surface and the third limiting part 15. This greatly enhances the holding force preventing the terminal from accidentally exiting the hole. The fourth limiting part 10 and the fifth limiting part 11 inside the sheath clamp the terminal from both sides, preventing it from wobbling in a plane perpendicular to the insertion direction, ensuring stable positioning of the terminal.

[0073] The above are merely preferred embodiments of the present invention and are not intended to limit the scope of the invention. Furthermore, the terms "vertical," "horizontal," "front," and "rear," etc., mentioned in the embodiments of the present invention indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product is in use. These are merely for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention. It should be further noted that, unless otherwise explicitly specified and limited, terms such as "install," "connect," "join," and "fix" in the description should be interpreted broadly. For example, "connect" can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, an indirect connection through an intermediate medium, or a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in the present invention according to the specific circumstances.

Claims

1. A connector for easy assembly and enhanced terminal positioning, comprising a TPA assembly (98), a sheath assembly (99), and a terminal assembly (97), characterized in that, The relative position between the TPA component (98) and the sheath component (99) includes a pre-lock position and a final lock position, wherein the TPA component (98) includes: TPA ontology; At least one cantilever beam (1), the cantilever beam (1) includes a fixed end and a free end, the fixed end is connected to the TPA body, and the free end extends to the locking direction of the TPA body; The first fastener (2) is located at or near the free end of the cantilever beam (1); The second clamp (3) is disposed on the cantilever beam (1) and is further away from the free end relative to the first clamp (2); The sheath assembly (99) includes: Sheath body; A slot (4) is provided on the sheath body, and the cantilever beam (1) is at least partially accommodated in the slot (4); Terminal hole (9) for mounting the terminal assembly (97); The second limiting part (8) and the first limiting part (6); when the TPA component (98) is in the pre-locked position, the second locking member (3) abuts against the second limiting part (8) to prevent the TPA component (98) from moving to the final locking position, and the first locking member (2) abuts against the first limiting part (6) to prevent the cantilever beam (1) from disengaging from the slot (4).

2. The connector for easy assembly and enhanced terminal positioning according to claim 1, characterized in that, The contact surface between the terminal assembly (97) and the first card (2) is the first surface (12) of the terminal. When the terminal assembly (97) is installed into the terminal hole (9) and the TPA assembly (98) is in the final lock position, the first card (2) and the first surface (12) of the terminal are in an interference fit.

3. The connector for easy assembly and enhanced terminal positioning according to claim 2, characterized in that, The contact surface between the first surface (12) of the terminal and the first card (2) is an interference plane or has several protrusions.

4. The connector for easy assembly and enhanced terminal positioning according to claim 2, characterized in that, The sheath assembly (99) further includes a third limiting part (15), and the terminal assembly (97) includes a terminal second surface (16). A terminal engaging surface is provided in the vertical direction on the terminal second surface (16). When the terminal assembly (97) is installed into the terminal hole (9), the third limiting part (15) abuts against the terminal engaging surface to prevent the terminal from disengaging from the terminal hole (9).

5. The connector according to claim 4, which facilitates assembly and enhances terminal positioning, is characterized in that, When the terminal assembly (97) is installed into the terminal hole (9) and the TPA assembly (98) is in the final locked position, the terminal assembly (97) is also biased toward the third limiting part (15) to increase the contact area between the terminal engagement surface and the third limiting part (15).

6. The connector according to claim 1, which facilitates assembly and enhances terminal positioning, is characterized in that, The first locking element (2) and the second locking element (3) are arranged in a staggered manner in the locking direction.

7. The connector according to claim 4, which facilitates assembly and enhances terminal positioning, is characterized in that, The sheath assembly (99) further includes a fourth limiting part (10) and a fifth limiting part (11), which are located on both sides inside the terminal hole and are respectively used to abut against the first surface (12) and the second surface (16) of the terminal, so that the terminal assembly (97) is normally limited in the insertion direction.

8. The connector for easy assembly and enhanced terminal positioning according to claim 2, characterized in that, When the terminal assembly (97) is inserted into the terminal hole (9), the first surface (12) of the terminal presses against the first clip (2), causing the cantilever beam (1) to undergo elastic deformation.

9. The connector according to claim 8, which facilitates assembly and enhances terminal positioning, is characterized in that, The sheath assembly (99) further includes a guide structure (13) located in the slot and adjacent to the second limiting part (8). When the cantilever beam (1) undergoes elastic deformation, the guide structure cooperates with the second locking member (3) to provide guidance and reduce movement resistance.

10. The connector according to claim 9, which facilitates assembly and enhances terminal positioning, is characterized in that, The guide structure is a rounded corner or C-corner structure.

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