current sensor

Abstract

This application relates to a current sensor. The current sensor includes a housing, a circuit board, and multiple pins. The circuit board is housed within the housing and has multiple sockets. Each pin has a coaxially connected cap and a stem. The stem passes through a corresponding socket and extends out of the housing. The radial dimension of the cap is larger than the radial dimension of the socket. The cap rests on the circuit board and is fixedly connected to it. By configuring the pins with a coaxially connected cap and stem structure, and by limiting the size of the cap so that its radial dimension is larger than the radial dimension of the socket, when the pin is inserted into the socket of the circuit board for installation, once the cap of the pin abuts against the circuit board, it can be determined that the pin is properly installed. Then, the cap of the pin is soldered to a metal pad on the circuit board. The limiting function of the pin cap allows for precise control of the length of the pin extending from the housing, preventing the pin from extending too far or too short, and ensuring reliable connection between the pin and the circuit board and external circuitry.

Description

Technical Field

[0001] This application relates to the field of sensor technology, and in particular to a current sensor. Background Technology

[0002] A current sensor is a device that converts a current signal into a measurable electrical signal. It is primarily used for real-time monitoring of current in circuits, enabling overload protection, energy metering, system control optimization, and safety early warning. It is widely used in power systems, industrial automation, new energy fields, consumer electronics, transportation, and medical equipment, providing crucial data support for safe equipment operation, energy management, and fault diagnosis. The pins, as the physical interface of the current sensor, are typically soldered to the internal circuit board, enabling physical and electrical connections to external circuits. However, existing pins that extend too far or too short from the current sensor are not conducive to connecting the pins to the internal circuit board or external circuits, leading to abnormal signal transmission (such as distortion or interruption), unstable power supply, and consequently, measurement errors, equipment malfunctions, or damage to the sensor and circuitry. Utility Model Content

[0003] Therefore, it is necessary to provide a current sensor to address the aforementioned technical problems.

[0004] A current sensor, comprising:

[0005] case;

[0006] A circuit board, wherein the circuit is disposed within the housing and has a plurality of sockets; and

[0007] Multiple pins, each pin having a cap and a rod coaxially connected, the rod passing through a corresponding insertion hole and extending out of the housing, the radial dimension of the cap being larger than the radial dimension of the insertion hole, the cap being mounted on the circuit board and fixedly connected to the circuit board.

[0008] In one embodiment, the cap and the rod form a smooth transition.

[0009] In one embodiment, the cap has a first end face near the rod, a second end face opposite to the first end face, and an outer peripheral surface located between the first end face and the second end face; the first end face and the outer peripheral surface have a first fillet, and / or the second end face and the outer peripheral surface have a second fillet.

[0010] In one embodiment, the sidewall of the housing has a mounting opening through which the circuit board can be mounted into the housing;

[0011] The bottom wall of the housing has multiple openings, the openings of which are adjacent to the mounting port, and the pin's shank can laterally enter the corresponding opening from the opening of the corresponding opening.

[0012] In one embodiment, the current sensor further includes a cover that covers the mounting opening and extends toward the interior of the housing. The cover has a plurality of limiting portions that can radially limit the rod portion of the corresponding pin.

[0013] In one embodiment, the limiting part is a limiting block facing the circuit board, and the limiting part has a limiting hole for the rod of the corresponding pin to pass through.

[0014] In one embodiment, the cover is further provided with at least one reinforcing part, which faces the circuit board and is connected between two adjacent limiting parts.

[0015] In one embodiment, the cover also has at least one support portion for supporting the circuit board.

[0016] In one embodiment, the side of the cover facing away from the circuit board is provided with at least one positioning part, which can be inserted into the corresponding opening slot from the slot of the corresponding opening slot to radially limit the rod of the corresponding pin.

[0017] In one embodiment, the cover includes a base plate, a first side plate, a second side plate, and a third side plate. The first side plate, the second side plate, and the third side plate are sequentially connected and are all located on the same side of the base plate. The base plate is provided with the limiting portion. The second side plate is fastened to the mounting opening. The end of the first side plate and / or the third side plate away from the second side plate has a guide surface. The distance between the guide surface and the base plate gradually increases along the direction closer to the mounting opening.

[0018] This application improves the pins of a current sensor. Specifically, the pins are designed with a coaxially connected cap and stem. By limiting the size of the cap, the radial dimension of the cap is made larger than the radial dimension of the socket. When the pin is inserted into the socket of the circuit board for installation, once the cap of the pin abuts against the circuit board, the pin is confirmed to be in place. Then, the cap of the pin is soldered to the metal pads on the circuit board. In other words, this application can precisely control the length of the pin extending from the housing by limiting the pin cap, avoiding the pin extending too much from the current sensor housing, which would result in a weak solder joint between the pin and the circuit board, and also avoiding the pin extending too little from the current sensor housing, which would result in poor contact with external circuits. Moreover, this application also connects the cap of the pin to the metal pads on the circuit board. Compared with the "I"-shaped pins, the contact area between the cap of the pin and the circuit board in this application is larger, which can increase the number of solder joints between the pin and the circuit board, thereby increasing the connection strength between the pin and the circuit board. Attached Figure Description

[0019] Figure 1 This is a three-dimensional structural diagram of a current sensor provided in an embodiment of this application, viewed from a first angle.

[0020] Figure 2 This is a three-dimensional structural diagram of a current sensor provided in an embodiment of this application, viewed from a second angle.

[0021] Figure 3 This is an exploded view of a current sensor provided in one embodiment of this application. It should be noted that... Figure 3 The current sensor shown does not have a cover.

[0022] Figure 4 This is a schematic diagram of the structure of a current sensor provided in an embodiment of this application when the cover assembly is not installed.

[0023] Figure 5 This is a schematic diagram of the circuit board and pins of a current sensor provided in one embodiment of this application.

[0024] Figure 6 This is a schematic diagram illustrating the mounting and mating of the pins and cover of a current sensor according to an embodiment of this application. Figure 6 The arrows in the diagram indicate the direction in which the stitches are inserted.

[0025] Figure 7 This is a schematic diagram of the structure of the cover of a current sensor provided in one embodiment of this application.

[0026] The labels in the attached diagram are explained as follows:

[0027] 10. Current sensor; 100. Housing; 110. Mounting port; 110a. First mounting port; 110b. Second mounting port; 120. Opening slot; 130. Locking block; 140. Support foot; 200. Circuit board; 300. Pin; 310. Cap; 311. First end face; 312. Second end face; 313. Outer peripheral surface; 320. Rod; 400. Encapsulation assembly; 410. Cover plate; 420. Cover seat; 421. Limiting part; 421a. Limiting hole; 422. Reinforcing part; 423. Support part; 420a. Base plate; 420b. First side plate; 420c. Second side plate; 420d. Third side plate; 420e. Guide surface; 424. Positioning part; 500. Magnetic core assembly; 510. Magnetic core; 520. Winding. Detailed Implementation

[0028] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0029] In the description of this application, it should be understood that if terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" appear, these terms indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application 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, and therefore should not be construed as a limitation of this application.

[0030] Furthermore, where the terms "first" and "second" appear, these terms are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, where the term "multiple" appears, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0031] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0032] In this application, unless otherwise expressly specified and limited, the use of descriptions such as "above" or "below" the second feature indicates that the first and second features are in direct contact or indirect contact via an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. Similarly, "below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0033] It should be noted that if an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. If an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. If so, the terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used in this application are for illustrative purposes only and do not represent the only possible implementation.

[0034] See Figures 1 to 4 One embodiment of this application provides a current sensor 10, which includes a housing 100, a circuit board 200, and a plurality of pins 300; the circuit board 200 is disposed in the housing 100 and has a plurality of sockets; as Figure 4 and Figure 5 The pin 300 has a cap 310 and a rod 320 coaxially connected. The rod 320 passes through a corresponding insertion hole and extends out of the housing 100. The radial dimension of the cap 310 is larger than the radial dimension of the insertion hole. The cap 310 is mounted on the circuit board 200 and fixedly connected to the circuit board 200. It should be noted that, in order to clearly show the structure of the pin 300, Figure 5 The rightmost pin 300 is not installed correctly.

[0035] The pins of the existing current sensor 10 are typically of a "I"-shaped rod structure, which are usually connected to the metal pads on the wall of the socket of the circuit board 200 by means of soldering. However, the length of the pin 300 extending from the housing of the current sensor 10 cannot be precisely controlled. If it extends too far, it makes soldering the pin 300 to the internal circuit board 200 difficult, resulting in a weak solder joint. If it extends too little, the pin 300 cannot be firmly inserted into the external circuit, which also leads to poor contact. In response, this application improves the pin 300 of the current sensor 10. Specifically, the pin 300 is configured with a cap 310 and a rod 320 coaxially connected. By limiting the size of the cap 310, the radial dimension of the cap 310 is made larger than the radial dimension of the socket. When the pin 300 is inserted into the socket of the circuit board 200 for installation, once the cap 310 of the pin 300 abuts against the circuit board 200, it can be determined that the pin 300 is installed in place. Then, the cap 310 of the pin 300 is soldered to the metal pad on the circuit board 200. That is, this application can use the limiting function of the cap 310 of the pin 300 to control the pin 300 from... The length of the extended portion of the housing 100 is precisely controlled to prevent the pin 300 from extending too far from the housing of the current sensor 10, which would result in a weak solder joint between the pin 300 and the circuit board 200. It also prevents the pin 300 from extending too little from the housing of the current sensor 10, which would result in poor contact with external circuits. Furthermore, this application connects the cap 310 of the pin 300 to the metal pad on the circuit board 200. Compared to the "I"-shaped pin, the cap 310 of the pin 300 in this application has a larger contact area with the circuit board 200, which can increase the number of solder joints between the pin 300 and the circuit board 200, thereby increasing the connection strength between the pin 300 and the circuit board 200.

[0036] It should be noted that the number of pins 300 is the same as the number of sockets on the circuit board 200, and the pins 300 and the sockets on the circuit board 200 correspond one-to-one.

[0037] In some embodiments of this application, the transition between the cap 310 and the rod 320 is smooth. This avoids stress concentration in the transition area between the cap 310 and the rod 320, and also prevents injury to the operator or damage to the circuit board 200 due to the sharpness of the transition area when inserting the pin 300. As an example, the transition area between the cap 310 and the rod 320 is designed to be concave and rounded.

[0038] In some embodiments of this application, such as Figure 5As shown, the cap portion 310 has a first end face 311 near the rod portion 320, a second end face 312 opposite to the first end face 311, and an outer peripheral surface 313 located between the first end face 311 and the second end face 312; wherein, the first end face 311 and the outer peripheral surface 313 have a first rounded corner, and the second end face 312 and the outer peripheral surface 313 have a second rounded corner. The provision of the first rounded corner and the second rounded corner can prevent the cap portion 310 of the needle 300 from scratching the operator when the needle 300 is inserted. Of course, in some other embodiments, one of the spaces between the first end face 311 and the outer peripheral surface 313 and between the second end face 312 and the outer peripheral surface 313 is provided with a rounded corner.

[0039] like Figure 3 and Figure 4 As shown, in some embodiments of this application, the current sensor 10 further includes a magnetic core assembly 500, which is disposed in the housing 100 and connected to the circuit board 200. The magnetic core assembly 500, as the core component of the current sensor 10, is mainly used to guide and concentrate the magnetic field generated by the current. As an example, the magnetic core assembly 500 may include a magnetic core 510 and a winding 520 disposed on the magnetic core 510.

[0040] Optionally, such as Figure 3 and Figure 4 The housing 100 includes a retaining block 130. The retaining block 130 limits the movement of the magnetic core assembly 500 within the housing 100, preventing it from wobbling. The retaining block 130 can be integrally molded with the housing 100 using methods such as injection molding, ensuring a strong connection between the retaining block 130 and the housing 100. The number of retaining blocks 130 can be set according to requirements, as long as they effectively limit the movement of the magnetic core assembly 500.

[0041] like Figure 3 As shown, in some embodiments of this application, the sidewall of the housing 100 has a mounting opening 110; as Figure 2 As shown, the current sensor 10 also includes a packaging assembly 400, which is disposed at the mounting port 110. The packaging assembly 400 is used to protect the components inside the housing 100.

[0042] Considering ease of processing, when processing the current sensor 10, the circuit board 200, magnetic core assembly 500, and pins 300 can be soldered externally first. Then, the circuit board 200, magnetic core assembly 500, and pins 300 can be moved as a whole into the housing 100, and finally, the encapsulation assembly 400 can be placed on the mounting port 110. To ensure that the circuit board 200, magnetic core assembly 500, and pins 300 can be smoothly installed as a whole on the housing 100, while avoiding an excessively large housing 100, this application improves the bottom wall structure of the housing 100. Specifically, as follows... Figure 3 and Figure 4 As shown, the bottom wall of the housing 100 has multiple openings 120. The openings of the openings 120 are adjacent to the mounting openings 110, and the rods 320 of the pins 300 can laterally enter the openings 120 through the corresponding openings. The openings 120 allow the circuit board 200, the magnetic core assembly 500, and the pins 300 to be mounted laterally on the housing 100 as a whole, without increasing the internal space of the housing 100 for mounting, thus miniaturizing the current sensor 10.

[0043] The number of opening slots 120 and pins 300 are the same, and they correspond one-to-one.

[0044] Optionally, such as Figure 1 and Figure 2 As shown, the bottom wall of the housing 100 is also provided with a plurality of support feet 140. The support feet 140 are located on the outer wall surface of the bottom wall of the housing 100 and can support the current sensor 10, facilitating the connection of the current sensor 10 to an external circuit. The number of support feet 140 can be two, three, four or more, and this application does not limit this.

[0045] like Figure 4 As shown, the mounting port 110 may include a first mounting port 110a and a second mounting port 110b, where the first mounting port 110a corresponds to the magnetic core assembly 500, and the second mounting port 110b corresponds to the circuit board 200; as Figure 2 As shown, the encapsulation assembly 400 includes a cover plate 410 and a cover seat 420; the cover plate 410 covers the first mounting port 110a, and the cover seat 420 covers the second mounting port 110b and extends toward the interior of the housing 100; wherein, as Figure 6 As shown, the cover 420 is provided with multiple limiting parts 421, which can radially limit the rod portion 320 of the corresponding pin 300. The limiting parts 421 can support the rod portion 320 of the pin 300, which can improve the stability of the pin 300 and prevent the pin 300 from bending or shaking when it is plugged into the external circuit.

[0046] In one embodiment, such as Figure 7 As shown, the cover 420 may include a base plate 420a, a first side plate 420b, a second side plate 420c, and a third side plate 420d. The first side plate 420b, the second side plate 420c, and the third side plate 420d are sequentially connected and all located on the same side of the base plate 420a. The base plate 420a is provided with a limiting part 421, and the second side plate 420c is fastened to the second mounting opening 110b. The cover 420 with this structure is not easily deformed and can be pushed into the housing 100 laterally from the second mounting opening 110b.

[0047] Optionally, the ends of the first side plate 420b and the third side plate 420d furthest from the second side plate 420c have guide surfaces 420e, and the distance between the guide surfaces 420e and the base plate 420a gradually increases along the direction closer to the mounting opening 110. This arrangement can guide the installation of the cover 420, facilitating its installation. The guide surfaces 420e can be inclined or curved.

[0048] Optionally, the base plate 420a, the first side plate 420b, the second side plate 420c and the third side plate 420d can be an integral structure, for example, formed by injection molding, so as to ensure the strength of the cover 420.

[0049] In one implementation, such as Figure 7 As shown, the limiting part 421 is a limiting block facing the circuit board 200. The limiting part 421 has a limiting hole 421a, through which the rod portion 320 of the corresponding pin 300 passes. With this configuration, the limiting part 421 can circumferentially limit the rod portion 320 of the corresponding pin 300. Specifically, the limiting hole 421a of the limiting part 421 is adapted to the rod portion 320 of the corresponding pin 300; for example, the diameter of the limiting hole 421a is equal to or slightly smaller than the outer diameter of the rod portion 320 of the corresponding pin 300.

[0050] The limiting part 421 can be integrated with the cover 420 to ensure the connection strength between the two. The number of limiting parts 421 can be the same as the number of pins 300, and the limiting parts 421 correspond one-to-one with the pins 300. Regarding the structure of the limiting part 421, it can be a circular ring, a square ring, or other regular rings, irregular rings, etc., and this application does not impose specific limitations here.

[0051] See also Figure 7 The cover 420 also includes at least one reinforcing part 422, which faces the circuit board 200 and connects between two adjacent limiting parts 421. The reinforcing part 422 improves the mounting strength of the limiting parts 421 on the cover 420, prevents deformation of the reinforcing part 422, effectively limits the circumferential position of the corresponding pin 300's rod portion 320, and also prevents the reinforcing part 422 from detaching from the cover 420. The number of reinforcing parts 422 can be set according to the number of limiting parts 421. For example, such as... Figure 7 As shown, the base plate 420a of the cover 420 has five limiting parts 421 along its length direction. A reinforcing part 422 is provided between every two adjacent limiting parts 421 on the left side, and a reinforcing part 422 is provided between every two limiting parts 421 on the right side. The terms "length direction" and "width direction" are used interchangeably throughout the text. Figure 7 The information shown shall prevail.

[0052] The surface of the reinforcing part 422 that is away from the base plate 420a may or may not be flush with the surface of the limiting part 421 that is away from the base plate 420a. The reinforcing part 422 may be integrally formed with the cover 420 by injection molding or other methods, which can ensure the connection strength between the reinforcing part 422 and the cover 420.

[0053] See also Figure 7 The cover 420 may also be provided with at least one support portion 423, which is used to support the circuit board 200. The support portion 423 is used to support and fix the circuit board 200.

[0054] Optionally, multiple support portions 423 can be provided on the side of the base plate 420a along the arrangement direction of the first side plate 420b, the second side plate 420c, and the third side plate 420d. Alternatively, support portions 423 can be provided in the middle of the base plate 420a. This ensures the secure mounting of the circuit board 200 on the cover 420. The number of support portions 423 can be set according to requirements. For example, such as... Figure 7 As shown, three support portions 423 are spaced apart between the first side plate 420b and the base plate 420a along the width direction of the base plate 420a, and one of the support portions 423 is also connected to the outermost limiting portion 421; three support portions 423 are also spaced apart between the third side plate 420d and the base plate 420a along the width direction of the base plate 420a, and one of the support portions 423 is also connected to the outermost limiting portion 421; five support portions 423 are also spaced apart between the second side plate 420c and the base plate 420a along the length direction of the base plate 420a, and each support portion 423 is also connected to the corresponding limiting portion 421; a support portion 423 is also provided in the middle of the base plate 420a, and this support portion 423 is also connected to the two limiting portions 421 in the middle.

[0055] Optionally, the support part 423 can be integrally formed with the cover 420 by injection molding or other methods, which can ensure the connection strength between the support part 423 and the cover 420.

[0056] Optionally, the surface of the support portion 423 that is away from the base plate 420a may protrude from the surface of the limiting portion 421 that is away from the base plate 420a or be flush with the surface of the limiting portion 421 that is away from the base plate 420a.

[0057] See Figure 6The cover 420, on the side facing away from the circuit board 200, is also provided with at least one positioning part 424. The positioning part 424 is inserted into the corresponding opening slot 120 from the slot opening 120 to radially limit the rod portion 320 of the corresponding pin 300. The positioning part 424 facilitates the installation of the cover 420 and can also provide a secondary radial limit for the rod portion 320 of the corresponding pin 300, thereby improving the stability of the pin 300 and preventing bending or shaking when the pin 300 is inserted into the external circuit. The number of positioning parts 424 is the same as the number of pins 300, and they correspond one-to-one.

[0058] Optionally, the positioning part 424 can be integrally formed with the cover 420 by injection molding or other methods, which can ensure the connection strength between the positioning part 424 and the cover 420.

[0059] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0060] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A current sensor, characterized in that, include: case; A circuit board, which is disposed in the housing and has multiple sockets; as well as Multiple pins, each pin having a cap and a rod coaxially connected, the rod passing through a corresponding insertion hole and extending out of the housing, the radial dimension of the cap being larger than the radial dimension of the insertion hole, the cap being mounted on the circuit board and fixedly connected to the circuit board.

2. The current sensor according to claim 1, characterized in that, The cap and the rod form a smooth transition.

3. The current sensor according to claim 1, characterized in that, The cap has a first end face near the rod, a second end face opposite to the first end face, and an outer peripheral surface located between the first end face and the second end face; the first end face and the outer peripheral surface have a first rounded corner, and / or the second end face and the outer peripheral surface have a second rounded corner.

4. The current sensor according to any one of claims 1 to 3, characterized in that, The side wall of the housing has a mounting opening, through which the circuit board can be mounted into the housing; The bottom wall of the housing has multiple openings, the openings of which are adjacent to the mounting port, and the pin's shank can laterally enter the corresponding opening from the opening of the corresponding opening.

5. The current sensor according to claim 4, characterized in that, The current sensor also includes a cover, which is fitted onto the mounting opening and extends toward the interior of the housing. The cover is provided with a plurality of limiting parts, which can radially limit the rod portion of the corresponding pin.

6. The current sensor according to claim 5, characterized in that, The limiting part is a limiting block facing the circuit board, and the limiting part has a limiting hole for the rod of the corresponding pin to pass through.

7. The current sensor according to claim 6, characterized in that, The cover also has at least one reinforcing part, which faces the circuit board and is connected between two adjacent limiting parts.

8. The current sensor according to claim 5, characterized in that, The cover also has at least one support portion for supporting the circuit board.

9. The current sensor according to claim 5, characterized in that, The cover seat is provided with at least one positioning part on the side opposite to the circuit board. The positioning part can be inserted into the corresponding opening slot from the slot of the corresponding opening slot to radially limit the rod of the corresponding pin.

10. The current sensor according to claim 5, characterized in that, The cover includes a base plate, a first side plate, a second side plate, and a third side plate. The first side plate, the second side plate, and the third side plate are connected in sequence and are all located on the same side of the base plate. The base plate is provided with the limiting part. The second side plate is fastened to the mounting opening. The end of the first side plate and / or the third side plate away from the second side plate has a guide surface. The distance between the guide surface and the base plate gradually increases along the direction closer to the mounting opening.

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