Electric automobile charging gun

Abstract

The utility model discloses a charging gun for an electric vehicle. The charging gun comprises a gun body, a gun head mounted at the front end of the gun body, and a terminal assembly mounted in the gun head, a terminal cavity is formed in the gun head, a first step part is formed in the terminal cavity, a supporting column is arranged between the first step part and the inner wall of the terminal cavity, and the supporting column is higher than the first step part in the first direction; the terminal assembly comprises a power terminal installed in the terminal cavity, and the power terminal comprises a front end cover which abuts against the first step portion in a limiting mode and a second step portion which abuts against the supporting column. According to the charging gun, the mounting structure of the terminal is optimized, lossless mounting of the terminal is realized while the mounting precision is ensured, the assembly cost is reduced, and the use safety of the charging gun is improved.

Description

Technical Field

[0001] The present application relates to the technical field of charging guns, and in particular to a charging gun for an electric vehicle. Background Art

[0002] In recent years, with the advocacy of the global low-carbon economy, new energy vehicles with zero emissions and high energy efficiency have gradually become the mainstream of the development of the automobile industry. The promotion of new energy electric vehicles can effectively alleviate the various pressures caused by human development on the environment, not only saving energy but also reducing greenhouse gas emissions. In the daily operation of new energy electric vehicles, the charging gun is a vital part. There are now a variety of charging guns on the market. Although the current charging guns can roughly meet the charging requirements, with the commissioning of various charging guns, the design drawbacks of various charging guns are becoming more and more prominent. Among them, the most obvious is the terminal installation. Since the terminal is inserted into the gun head, it is easy to have excessive installation force or improper installation position during the installation process, which will cause the terminal to be damaged and unusable. This not only increases the assembly cost, but also easily causes safety hazards during charging. Utility Model Content

[0003] The purpose of the embodiments of the present application is to provide an electric vehicle charging gun, which optimizes the terminal installation structure to achieve lossless installation of the terminal while ensuring installation accuracy, reduce assembly costs, and improve the safety of the charging gun.

[0004] To achieve the above objectives, this application adopts the following technical solutions:

[0005] On the one hand, a charging gun for an electric vehicle is provided, comprising: a gun body, a gun head installed at the front end of the gun body, and a terminal assembly installed in the gun head; a terminal cavity is opened in the gun head, a first step portion is formed in the terminal cavity, a support column is arranged between the first step portion and the inner wall of the terminal cavity, and the support column is higher than the first step portion in a first direction; the terminal assembly comprises a power terminal installed in the terminal cavity, the power terminal comprises a front end cover which is limitedly abutted against the first step portion, and a second step portion abutted against the support column.

[0006] Furthermore, a plurality of support columns are provided and are evenly spaced between the first step portion and the inner wall of the terminal cavity.

[0007] Furthermore, a surface area of ​​the first step portion on a side opposite to the front end cover is larger than a surface area of ​​the front end cover.

[0008] Furthermore, it also includes an end clamping seat, the terminal assembly is installed on the end clamping seat, and the end clamping seat is clamped in the gun head.

[0009] Furthermore, a plurality of buckles are provided on the end clamping seat, and a clamping groove which is engaged with the buckles is provided on the gun head.

[0010] Furthermore, there are three buckles, which are arranged in a triangle on the end clamping seat.

[0011] Furthermore, the terminal assembly also includes a ground terminal and a signal terminal, and the ground terminal and the signal terminal are both installed on the end holder and penetrated into the gun head.

[0012] Furthermore, the terminal holder is provided with a first clamping hole for clamping the power terminal, a second clamping hole for clamping the ground terminal, and a third clamping hole for clamping the signal terminal.

[0013] Furthermore, the gun head includes a first mounting portion and a second mounting portion which are arranged at intervals, the power terminal is mounted on the first mounting portion, and the ground terminal and the signal terminal are both mounted on the second mounting portion.

[0014] Furthermore, it also includes at least two temperature sensors, two of which are provided at the power terminals, and the two temperature sensors are both installed on the terminal holder to respectively detect the temperatures of the two power terminals.

[0015] Furthermore, a waterproof ring is provided at the connection position between the gun head and the end clamp.

[0016] The beneficial effects of the present application are as follows: the first step portion provided on the gun head and the support column together constitute a guiding structure, which can ensure that the power terminal can be accurately installed in the terminal cavity, and the first step portion abuts against the front end cover of the power terminal to play a limiting role, and the support column abuts against the second step portion of the power terminal to play a supporting and protective role, avoiding damage to the front end when the power terminal is inserted forward. In addition, the first step portion limits the installation position of the power terminal, and can also play a role in preventing touch, thereby improving its safety in use. The present application achieves lossless installation of the power terminal by optimizing the terminal installation structure, which can effectively reduce the assembly cost and improve the overall quality of the charging gun. It can also ensure that the power terminal is accurately inserted into the terminal cavity, thereby improving the installation accuracy. Lossless installation and precise installation position ensure the stability and safety of the charging gun during the charging process, and reduce the safety hazards caused by terminal damage or improper installation. At the same time, due to the use of an optimized installation structure, the maintenance and replacement of the power terminal also become more convenient and quick, further improving the convenience of using the charging gun. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The present application is further described in detail below based on the drawings and embodiments.

[0018] Figure 1This is a three-dimensional diagram of the electric vehicle charging gun described in the embodiment of the present application;

[0019] Figure 2 This is a schematic diagram of an explosion of an electric vehicle charging gun according to an embodiment of the present application;

[0020] Figure 3 A side view of the gun tip and terminal assembly according to an embodiment of the present application;

[0021] Figure 4 For this application Figure 3 Schematic diagram of the cross section at AA in the middle;

[0022] Figure 5 A three-dimensional diagram of the gun tip according to an embodiment of the present application;

[0023] Figure 6 A side view of the gun tip according to an embodiment of the present application;

[0024] Figure 7 A three-dimensional diagram of the end card holder described in the embodiment of the present application;

[0025] Figure 8 It is a three-dimensional diagram of the power terminal described in the embodiment of the present application.

[0026] In the figure: 1. gun body; 2. gun head; 201. terminal cavity; 202. first step portion; 203. support column; 204. slot; 205. first mounting portion; 206. second mounting portion; 3. terminal assembly; 301. power terminal; 302. ground terminal; 303. signal terminal; 3011. front end cover; 3012. second step portion; 4. end socket; 401. first clamping hole; 402. second clamping hole; 403. third clamping hole; 404. buckle; 5. waterproof ring; 6. temperature sensor. DETAILED DESCRIPTION

[0027] In order to make the technical problems solved by this application, the technical solutions adopted, and the technical effects achieved more clearly, the technical solutions of the embodiments of this application are further described in detail below. Obviously, the described embodiments are only part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of this application.

[0028] In the description of this application, unless otherwise clearly specified and limited, the terms "connected", "connected", and "fixed" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0029] In the present application, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0030] like Figure 1-Figure 8 As shown, this embodiment provides an electric vehicle charging gun, comprising: a gun body 1, a gun head 2 installed at the front end of the gun body 1, and a terminal assembly 3 installed in the gun head 2; a terminal cavity 201 is opened in the gun head 2, and a first step portion 202 is formed in the terminal cavity 201, and a support column 203 is arranged between the first step portion 202 and the inner wall of the terminal cavity 201, and the support column 203 is higher than the first step portion 202 in a first direction; the terminal assembly 3 includes a power terminal 301 installed in the terminal cavity 201, and the power terminal 301 includes a front end cover 3011 which is limitedly abutted against the first step portion 202, and a second step portion 3012 which abuts against the support column 203.

[0031] Based on the above scheme, when it is necessary to install the power terminal 301 into the terminal cavity 201 in the gun head 2, the user first ensures that the front cover 3011 of the power terminal 301 is aligned with the first step portion 202 and is limitedly abutted. This design ensures the correct installation position of the terminal in the front-to-back direction and avoids the problem of improper installation position. At the same time, the second step portion 3012 of the power terminal 301 abuts against the support column 203 in the terminal cavity 201. The support column 203 is higher than the first step portion 202 in the first direction, which means that the support column 203 will first contact the second step portion 3012 of the power terminal 301 during the insertion of the power terminal 301. This design has two main functions: one is that the support column 203 provides additional support for the power terminal 301, preventing the terminal from being deformed or damaged due to excessive installation force during the insertion process. This support function ensures the lossless installation of the terminal and reduces the assembly cost. The other is that the support column 203 and the first step portion 202 together constitute a guide structure to guide the power terminal 301 to be correctly inserted into the terminal cavity 201. This guiding effect not only improves the installation accuracy, but also reduces the installation difficulty and error rate. In general, by optimizing the terminal installation structure, the lossless installation of the power terminal 301 is achieved, which can effectively reduce the assembly cost and improve the overall quality of the charging gun. It can also ensure that the power terminal 301 is accurately inserted into the terminal cavity 201, thereby improving the installation accuracy. Lossless installation and precise installation position ensure the stability and safety of the charging gun during the charging process, and reduce safety hazards caused by terminal damage or improper installation. At the same time, due to the use of an optimized installation structure, the maintenance and replacement of the power terminal 301 also become more convenient and quick, further improving the convenience of using the charging gun.

[0032] Furthermore, the support columns 203 are provided in plurality and are evenly spaced between the first step portion 202 and the inner wall of the terminal cavity 201. When the power terminal 301 begins to be inserted into the terminal cavity 201, its second step portion 3012 first contacts the plurality of support columns 203. Since the support columns 203 are evenly spaced, they can evenly share the installation force, ensuring the stable installation of the power terminal 301 in the front-to-back direction, and can also avoid deformation or damage of the terminal due to excessive local force, further improving the lossless installation rate of the terminal and reducing the assembly cost; at the same time, the even distribution of the plurality of support columns 203 also provides a better guiding effect, so that the power terminal 301 can be more accurately inserted into the predetermined installation position.

[0033] At the same time, the surface area of ​​the first step portion 202 relative to the front end cover 3011 is larger than the surface area of ​​the front end cover 3011. In the design of the electric vehicle charging gun, the first step portion 202 on the gun head 2 is particularly thickened so that its surface area relative to the front end cover 3011 side of the power terminal 301 is larger. Such a design is mainly based on the principle of increasing the contact area and dispersing the pressure. When the power terminal 301 is inserted forward, the front end cover 3011 first contacts the first step portion 202. Since the surface area of ​​the first step portion 202 is larger than the surface area of ​​the front end cover 3011, the increase in the contact area makes the pressure distribution more uniform and reduces the pressure per unit area. In this way, even if there is a large installation force during the installation process, the damage to the front end cover 3011 by this force can be dispersed and reduced through a large area of ​​contact. At the same time, the thickened first step portion 202 not only enhances its own structural strength, but also better protects the front end cover 3011 to prevent the front end cover 3011 from being damaged by excessive extrusion or scratching during the installation process. In addition, since the first step portion 202 remains intact after being thickened, its anti-touch function is also retained, ensuring the safety of the user during use.

[0034] The existing terminal holder 4 and the gun head 2 are mostly installed by screw fixing, which may cause the terminal holder 4 and the gun head 2 to be squeezed, deformed and damaged during installation and manufacturing, and the terminal assembly 3 may be easily exposed after multiple uses, resulting in electric shock accidents. Therefore, the scheme also includes an terminal holder 4, and the terminal assembly 3 is installed on the terminal holder 4, and the terminal holder 4 is clamped in the gun head 2. The terminal holder 4 serves as a mounting base for the terminal assembly 3, and its structure needs to match the internal structure of the gun head 2. The terminal holder 4 is provided with a slot or mounting hole matching the power terminal 301 to ensure that the terminal assembly 3 can be firmly installed on the terminal holder 4. The gun head 2 is provided with a slot 204 or a buckle 404 matching the terminal holder 4 to ensure that the terminal holder 4 can be firmly clamped in the gun head 2. The design of the slot 204 or the buckle 404 should take into account the convenience of installation and disassembly of the terminal holder 4, while ensuring the connection stability. Compared with the screw fixing method, the clamping method does not require the use of tools, and the installation process is simpler and faster. At the same time, it avoids the problem of extrusion, deformation and damage of the end clamping seat 4 and the gun head 2 caused by screw fixing.

[0035] Specifically, the terminal holder 4 is provided with a plurality of buckles 404, and the gun head 2 is provided with a slot 204 that is engaged with the buckles 404. Through the cooperation between the buckles 404 and the slots 204, the installation of the terminal holder 4 and the gun head 2 can be completed without the use of tools, which greatly simplifies the installation steps; the precise cooperation between the buckles 404 and the slots 204 can ensure that the installation position of the terminal holder 4 in the gun head 2 is accurate, thereby improving the installation accuracy. The snap-on connection method can ensure that the terminal holder 4 is firmly installed inside the gun head 2, and is not easy to loosen or fall off, thereby enhancing the structural stability of the charging gun. The stable snap-on connection method can ensure that the terminal assembly 3 is firmly installed inside the gun head 2, reducing the risk of exposure due to looseness, thereby reducing the incidence of electric shock accidents, while avoiding the problem of extrusion, deformation and damage of the terminal holder 4 and the gun head 2 caused by screw fixation, thereby reducing the manufacturing cost and maintenance difficulty.

[0036] More specifically, there are three buckles 404, which are arranged in a triangular shape on the end holder 4. The triangular structure is known for its stability in geometry. The use of the buckles 404 arranged in a triangular shape on the end holder 4 can ensure that the end holder 4 is evenly supported and fixed inside the gun head 2, thereby greatly enhancing the stability of the connection. Even in the case of external impact or vibration, this design can effectively prevent the end holder 4 from being displaced or loosened. Due to the stability of the triangular buckles 404, the installation of the end holder 4 inside the gun head 2 is more reliable, reducing the risk of damage caused by improper installation or long-term use, which not only extends the service life of the charging gun, but also reduces maintenance costs. Moreover, the arrangement of the triangular buckles 404 enables the force on the end holder 4 inside the gun head 2 to be evenly distributed, avoiding the situation of excessive local force, helping to reduce the risk of damage caused by stress concentration, and at the same time improving the stability and durability of the entire charging gun structure.

[0037] In addition, for the distribution of the buckles 404 on the end clamp 4, in addition to the triangular arrangement, the following distribution methods can also be considered to ensure a stable connection between the end clamp 4 and the gun head 2:

[0038] Quadrilateral distribution: buckles 404 are set on the four corners or edges of the end clamp 4 to form a quadrilateral distribution. The quadrilateral structure also has good stability and can ensure that the end clamp 4 is evenly stressed in the gun head 2. This method is suitable for situations where the gun head 2 is larger and requires more support points.

[0039] Symmetrical distribution: According to the shape and size of the end clamp 4, the buckles 404 are symmetrically distributed on both sides or multiple symmetrical points of the end clamp 4. Symmetrical distribution can ensure the balance and stability of the end clamp 4 in the gun head 2, reduce the deflection or shaking caused by improper installation, and is suitable for scenes with high requirements for installation accuracy and stability.

[0040] Linear distribution: Arrange the buckles 404 along one side or a straight line of the end holder 4. Linear distribution can simplify the design and installation process while ensuring a stable connection in a specific direction, and is suitable for situations where the internal space of the gun head 2 is limited and connection along a specific direction is required.

[0041] Central distribution: The buckles 404 are concentrated in the central area of ​​the end clamp 4. The central distribution can ensure the stable support of the end clamp 4 in the gun head 2, reduce the shaking caused by external forces, and is suitable for situations with specific requirements on the support point position, such as the need to ensure the utilization rate of the internal space of the gun head 2.

[0042] In practical applications, the distribution of the buckles 404 should be considered comprehensively based on the shape, size, internal space, and installation requirements of the gun head 2. A reasonable distribution design of the buckles 404 can ensure a stable connection between the end holder 4 and the gun head 2, thereby improving the safety and reliability of the charging gun.

[0043] In some embodiments, the terminal assembly 3 further includes a ground terminal 302 and a signal terminal 303, both of which are mounted on the end clamp 4 and penetrated into the gun head 2. At the same time, the end clamp 4 is provided with a first clamp hole 401 for clamping the power terminal 301, a second clamp hole 402 for clamping the ground terminal 302, and a third clamp hole 403 for clamping the signal terminal 303. In the design of the electric vehicle charging gun, the end clamp 4 not only carries the power terminal 301, but also carries the ground terminal 302 and the signal terminal 303. These terminals are key components for the normal operation of the charging gun. In order to ensure that these terminals can be stably and safely installed inside the gun head 2, the design of the end clamp 4 is particularly important. The first clamping hole 401 is specially designed for the power terminal 301, and its size and shape match the power terminal 301, ensuring that the power terminal 301 can be firmly clamped in the first clamping hole 401. Specifically, the power terminal 301 is installed on the end clamping seat 4 by passing through the gun head 2, and is clamped in the first clamping hole 401. During installation, it should be ensured that the power terminal 301 is fully matched with the first clamping hole 401 without looseness. The second clamping hole 402 is used for the installation of the grounding terminal 302, and its size and shape match the grounding terminal 302 to ensure the stable connection of the grounding terminal 302. The grounding terminal 302 is also installed on the end clamping seat 4 by passing through the gun head 2, and is clamped in the second clamping hole 402. The installation of the grounding terminal 302 should ensure that it is in good contact with the grounding structure inside the gun head 2 to achieve effective grounding protection. The third clamping hole 403 is designed for the signal terminal 303, and its size and shape match the signal terminal 303 to ensure the stability and reliability of signal transmission. The signal terminal 303 is also installed on the end holder 4 by penetrating the gun head 2 and is clamped in the third clamping hole 403. The installation of the signal terminal 303 should ensure that it is well connected with the signal transmission structure inside the gun head 2 to achieve stable and reliable signal transmission.

[0044] Optionally, the gun head 2 includes a first mounting portion 205 and a second mounting portion 206 arranged at intervals, the power terminal 301 is mounted on the first mounting portion 205, and the ground terminal 302 and the signal terminal 303 are both mounted on the second mounting portion 206. The first mounting portion 205 is mainly used to mount the power terminal 301. Since the power terminal 301 is usually large and needs to withstand a large current, mounting it on a separate first mounting portion 205 can ensure sufficient space and support. The second mounting portion 206 is mainly used to mount the ground terminal 302 and the signal terminal 303. Since the ground terminal 302 and the signal terminal 303 are usually small and have different functions, mounting them on the same second mounting portion 206 can facilitate management and maintenance. By dividing the gun head 2 into two mounting portions arranged at intervals, the power terminal 301, the ground terminal 302 and the signal terminal 303 each have an independent installation space, and the structure is clearer, which is convenient for management and maintenance.

[0045] In addition, at least two temperature sensors 6 are included. Two of the power terminals 301 are provided. The two temperature sensors 6 are installed on the terminal holder 4 to respectively detect the temperature of the two power terminals 301. The two power terminals 301 are respectively connected to the positive pole and the negative pole to realize the transmission of electric energy. The two temperature sensors 6 respectively detect the temperature of the two power terminals 301. By real-time monitoring the temperature of the power terminals 301, it can be ensured that the temperature during the charging process is controlled within a safe range, avoiding safety hazards caused by overheating, and helping to improve the stability and reliability of the charging gun.

[0046] In the design of electric vehicle charging guns, waterproof performance is a crucial consideration. Especially in outdoor or humid environments, if the waterproof performance of the charging gun is poor, it will not only affect its normal operation, but may also bring safety hazards. Therefore, in order to improve the waterproof performance of the gun head 2 and the end clamp 4, a waterproof ring 5 is provided at the connection position between the gun head 2 and the end clamp 4, which can significantly improve the waterproof performance of the charging gun. Among them, the waterproof ring 5 is an annular seal made of rubber or other elastic materials, which is installed at the connection between the gun head 2 and the end clamp 4 to form a tight sealing structure. This design is intended to prevent moisture, dust and other foreign substances from invading the interior of the gun head 2, thereby protecting the internal circuits and components from damage.

[0047] In the description of this article, it should be understood that the terms "upper", "lower", "left", "right", etc., and other directions or positional relationships are only for the convenience of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation of this application. In addition, the terms "first" and "second" are only used to distinguish in the description and have no special meaning.

[0048] In the description of this specification, the description with reference to the terms "an embodiment", "example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example.

[0049] In addition, it should be understood that although this specification is described according to implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

[0050] The technical principles of the present application are described above in conjunction with specific embodiments. These descriptions are only for explaining the principles of the present application and cannot be interpreted as limiting the scope of protection of the present application in any way. Based on the explanations herein, those skilled in the art can think of other specific implementation methods of the present application without creative work, and these methods will fall within the scope of protection of the present application.

Claims

1. An electric vehicle charging gun, characterized in that: include: A gun body (1), a gun head (2) installed at the front end of the gun body (1), and a terminal assembly (3) installed in the gun head (2); a terminal cavity (201) is opened in the gun head (2), a first step portion (202) is formed in the terminal cavity (201), a support column (203) is arranged between the first step portion (202) and the inner wall of the terminal cavity (201), and the support column (203) is higher than the first step portion (202) in a first direction; the terminal assembly (3) includes a power terminal (301) installed in the terminal cavity (201), and the power terminal (301) includes a front end cover (3011) that is limitedly abutted against the first step portion (202), and a second step portion (3012) that is abutted against the support column (203).

2. The electric vehicle charging gun according to claim 1, characterized in that: A plurality of support columns (203) are provided, and are evenly spaced between the first step portion (202) and the inner wall of the terminal cavity (201).

3. The electric vehicle charging gun according to claim 1, characterized in that: The surface area of ​​the first step portion (202) on the side opposite to the front end cover (3011) is greater than the surface area of ​​the front end cover (3011).

4. The electric vehicle charging gun according to any one of claims 1 to 3, characterized in that: It also comprises an end clamping seat (4), the terminal assembly (3) is mounted on the end clamping seat (4), and the end clamping seat (4) is clamped in the gun head (2).

5. The electric vehicle charging gun according to claim 4, characterized in that: The end clamping seat (4) is provided with a plurality of buckles (404), and the gun head (2) is provided with a clamping groove (204) that cooperates with the buckles (404) for clamping.

6. The electric vehicle charging gun according to claim 5, characterized in that: The buckles (404) are provided in three numbers and are arranged in a triangle on the end clamping seat (4).

7. The electric vehicle charging gun according to claim 4, characterized in that: The terminal assembly (3) further comprises a grounding terminal (302) and a signal terminal (303), wherein the grounding terminal (302) and the signal terminal (303) are both mounted on the end clamping seat (4) and are inserted into the gun head (2); the end clamping seat (4) is provided with a first clamping hole (401) for clamping the power terminal (301), a second clamping hole (402) for clamping the grounding terminal (302), and a third clamping hole (403) for clamping the signal terminal (303).

8. The electric vehicle charging gun according to claim 7, characterized in that: The gun head (2) comprises a first mounting portion (205) and a second mounting portion (206) arranged at intervals, the power terminal (301) is mounted on the first mounting portion (205), and the ground terminal (302) and the signal terminal (303) are both mounted on the second mounting portion (206).

9. The electric vehicle charging gun according to claim 4, characterized in that: A waterproof ring (5) is provided at the connection position between the gun head (2) and the end clamping seat (4).

10. The electric vehicle charging gun according to claim 4, characterized in that: It also comprises at least two temperature sensors (6), two of which are provided for the power terminals (301), and the two temperature sensors (6) are both mounted on the end holder (4) and are used to respectively detect the temperatures of the two power terminals (301).

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