Charging inlet and automobile with terminals centered with high precision

Abstract

The present application provides a charging inlet and a vehicle with a terminal centered with high accuracy, the charging inlet has a cavity for accommodating a charging terminal, a gap exists between an inner peripheral wall of the cavity and an outer peripheral wall of the charging terminal, a supporting elastic piece is provided in the gap, the supporting elastic piece is arranged along the circumferential direction of the charging terminal, and the supporting elastic piece is configured to limit the misalignment of the axis of the charging terminal and the axis of the cavity. The charging inlet according to the present application automatically centers the mating terminal with high accuracy and fully inserts the mating terminal into contact, thereby reducing the contact resistance between the charging terminal and the mating terminal, improving the electrical performance of the charging inlet, reducing the risks of charging with the charging inlet, and extending the service life of the charging inlet.

Description

[Technical Field]

[0001] Related Applications This application claims priority to a Chinese patent filed on September 15, 2021, with application number 202111083188.7, entitled "Charging inlet with terminals centered with high precision and automobile," the entire contents of which are incorporated herein by reference.

[0002] Technical Field The present application relates to the field of charging technology, and more particularly to a charging inlet and a vehicle having terminals that are precisely centered. [Background technology]

[0003] As new energy vehicles become more popular, the number of charging equipment and devices that come with them is also increasing. However, fires and other accidents still occur frequently when existing new energy vehicles are charging or discharging. Most fires during charging and discharging are caused by excessive temperature rise during the transmission of electrical energy. The reason for this is that the contact resistance between the terminals where the charging equipment is inserted is too high, and the charging current is also large, which causes a sudden rise in temperature at the terminal contact points, ultimately causing a fire in the entire charging system.

[0004] The charging terminals in currently available charging inlets are generally female terminals, and for ease of installation during assembly and to allow for easy insertion of the male terminal at the mating end if there is room for movement, a certain gap is provided between the charging terminal in the charging inlet and the side wall where it is installed.After the charging terminal in the charging inlet and the male terminal at the mating end are inserted, they are not concentric, resulting in a small contact area between the terminals and excessive contact resistance, which can cause excessive temperature rise between the terminals and ultimately lead to a fire.

[0005] Therefore, in the field of charging technology, there is a need for a charging inlet that automatically centers the mating terminal with high precision and ensures perfect insertion and contact of the mating terminal. Summary of the Invention

[0006] Disclosure of the Invention The present application aims to provide a charging inlet with highly accurate centered terminals that can automatically center mating terminals with high precision and ensure complete mating contact, thereby reducing the contact resistance of the mating terminals, improving the electrical performance of the charging inlet, reducing the risk of fire when charging with the charging inlet, and extending the service life of the charging inlet.

[0007] The above object of the present application is achieved by the following technical means.

[0008] A charging inlet in which the terminal is centered with high precision, the charging inlet having a cavity for accommodating the charging terminal, a gap existing between the inner peripheral wall of the cavity and the outer peripheral wall of the charging terminal, a support elastic piece provided in the gap, the support elastic piece arranged along the circumferential direction of the charging terminal, and the support elastic piece configured to limit misalignment between the axis of the charging terminal and the axis of the cavity.

[0009] The present application provides a vehicle equipped with a charging inlet in which the terminals are centered with high precision.

[0010] This application has the following features and advantages:

[0011] 1. In the charging inlet, a supporting elastic piece is provided in the circumferential direction of the charging terminal, which supports the charging terminal in the center of the cavity of the charging inlet. When the mating terminal is inserted, it is directly and completely mated with and makes contact with the charging terminal, and the mating terminal is completely inserted and makes contact without shifting from the axis during use, thereby reducing the contact resistance of the mating terminal, improving the electrical performance of the charging inlet, reducing the risk of fire when charging with the charging inlet, and extending the service life of the charging inlet.

[0012] 2. In this charging inlet, the elastic support pieces are attached to the charging terminal at uniform intervals in the circumferential direction, stably fixing the charging terminal in the center of the cavity. Meanwhile, the maximum diameter of the outer periphery of the elastic support pieces is larger than the inner diameter of the cavity, and the elastic support pieces apply pressure to the inner wall of the cavity, so that the charging terminal can be kept in the center of the cavity when inserted.

[0013] 3. In the charging inlet, the supporting elastic piece has multiple styles, multiple cross-sectional shapes, multiple metal materials, and multiple connection methods, which increases the designer's range of options and allows them to select multiple materials to suit different usage environments.

[0014] 4. In the charging inlet, a plating layer can be formed on the supporting elastic piece and / or the elastic sheet to enhance the corrosion resistance of the charging terminal, improve the wear resistance of the contact points, and extend the service life of the charging inlet. [Brief explanation of the drawings]

[0015] In the following, in order to more clearly explain the technical solutions of the embodiments of the present application, the drawings in the embodiments will be briefly described. However, the following drawings are only some of the embodiments of the present application, and it goes without saying that those skilled in the art can obtain other drawings based on these drawings without any innovative ingenuity. [Figure 1] FIG. 1 is a structural schematic diagram of one embodiment of a charging inlet according to the present application. [Figure 2] FIG. 2 is a structural schematic diagram of an embodiment of a charging terminal according to the present application. [Figure 3] FIG. 3 is a schematic diagram of the radial cross section of the charging terminal according to the present application. [Figure 4] 4-13 are cross-sectional schematic views of alternative embodiments of charging inlets according to the present application. [Figure 5] 4-13 are cross-sectional schematic views of alternative embodiments of charging inlets according to the present application. [Figure 6] 4-13 are cross-sectional schematic views of alternative embodiments of charging inlets according to the present application. [Figure 7] 4-13 are cross-sectional schematic views of alternative embodiments of charging inlets according to the present application. [Figure 8] 4-13 are cross-sectional schematic views of alternative embodiments of charging inlets according to the present application. [Figure 9] 4-13 are cross-sectional schematic views of alternative embodiments of charging inlets according to the present application. [Figure 10] 4-13 are cross-sectional schematic views of alternative embodiments of charging inlets according to the present application. [Figure 11] 4-13 are cross-sectional schematic views of alternative embodiments of charging inlets according to the present application. [Figure 12] 4-13 are cross-sectional schematic views of alternative embodiments of charging inlets according to the present application. [Figure 13] 4-13 are cross-sectional schematic views of alternative embodiments of charging inlets according to the present application. [Figure 14] FIG. 14 is a schematic structural diagram of a radial cross section of another embodiment of a charging terminal according to the present application. [Figure 15] FIG. 15 is a structural schematic diagram of yet another embodiment of the charging inlet according to the present application. [Explanation of symbols]

[0016] 1, charging inlet; 11, cavity; 2, charging terminal; 21, terminal body; 22, elastic sheet; 23, insertion hole; 3, supporting elastic piece; 31, elastic sheath; 4. Ring. DETAILED DESCRIPTION OF THE INVENTION

[0017] BEST MODE FOR CARRYING OUT THE INVENTION The technical solutions in the embodiments of the present application will be explained clearly and completely below with reference to the drawings in the embodiments of the present application, and of course, the embodiments described herein are only some of the embodiments of the present application and do not include all of the embodiments. It should be understood that all other embodiments obtained based on the embodiments of the present application without any innovative ideas fall within the scope of protection of the present application.

[0018] Example 1 This application provides a charging inlet 1 with terminals that are centered with high precision, as shown in Figures 1 to 3 . The charging inlet 1 has a cavity 11 that accommodates the charging terminal 2, a gap exists between the inner wall of the cavity 11 and the outer wall of the charging terminal 2, and a supporting elastic piece 3 is provided in the gap, arranged along the circumferential direction of the charging terminal 2, and is configured to limit misalignment between the axis of the charging terminal 2 and the axis of the cavity 11. In this charging inlet 1, the supporting elastic piece 3 is arranged along the circumferential direction of the charging terminal 2, supporting the charging terminal 2 in the center of the cavity of the charging inlet 1, allowing the mating terminal to be directly and completely inserted into and contact with the charging terminal 2 when inserted, and allowing the mating terminal to be completely inserted into and contact with the charging terminal 2 without misalignment from the axis during use, reducing the contact resistance of the mating terminal, improving the electrical performance of the charging inlet 1, reducing the risk of fire when charging with the charging inlet 1, and extending the service life of the charging inlet 1.

[0019] In some embodiments, the ratio of the maximum gap width to the maximum diameter of the charging terminal 2 is in the range of 0.01-0.7. If the ratio of the maximum gap width to the maximum diameter of the charging terminal 2 is too small, the amount of movement of the charging terminal 2 in the gap is small, and when the mating terminal is eccentric, the charging terminal 2 is easily damaged, contact resistance increases, and temperature rise increases. If the ratio of the maximum gap width to the maximum diameter of the charging terminal 2 is too large, the amount of movement of the charging terminal 2 in the gap is too large, and the charging terminal 2 and the mating terminal are inserted at an angle, reducing the contact area and similarly increasing the contact resistance, increasing the temperature at the insertion site, and raising the temperature of the charging inlet.

[0020] In order to verify the effect of the ratio of the maximum gap width to the maximum diameter of the charging terminal 2 on the temperature rise value of the charging terminal 2, the inventors conducted 1,000 insertion experiments with the insertion charging gun head using charging terminals 2 with the same dimensions and specifications and charging inlets 1 with different ratios of the maximum gap width to the maximum diameter of the charging terminal 2, and tested the contact resistance and temperature rise value of the contact area between the charging terminal 2 and the insertion terminal, and recorded the results in Table 1.

[0021] The contact resistance was tested as follows: a microresistance meter was used, with one end of the meter placed on the mating terminal and the other end on the charging terminal 2. The meter was placed in the same position each time a measurement was taken, and the contact resistance reading on the meter was read. In this example, a contact resistance greater than 1 mΩ was deemed defective.

[0022] The temperature rise was measured as follows: A precision temperature sensor was attached to the charging terminal 2, and if necessary, heat-transfer silicone grease could be applied to the contact surface to measure the temperature more accurately. The temperature value indicated by the precision temperature sensor was then read when the charging terminal 2 was in an inactive state. The charging terminal 2 was then connected to the mating terminal and a current was passed through it. After the temperature of the charging terminal 2 stabilized, the temperature value indicated by the precision temperature sensor was read. The absolute value of the difference between these values ​​was taken as the temperature rise value of the charging terminal 2. In this example, a temperature rise value of less than 10 K was considered to be acceptable. The experimental results are shown in Table 1. [Table 1]

[0023] As shown in Table 1, when the ratio of the maximum gap width to the maximum diameter of the charging terminal 2 is less than 0.01, the contact resistance between the mating terminal and the charging terminal 2 exceeds 1 mΩ, which is too high and causes the temperature rise of the charging terminal 2 to exceed 10 K. Furthermore, when the ratio of the maximum gap width to the maximum diameter of the charging terminal 2 exceeds 0.7, the contact resistance between the mating terminal and the charging terminal 2 exceeds 1 mΩ, which is too high and causes the temperature rise of the charging terminal 2 to exceed 10 K, resulting in a rise in the temperature of the charging inlet 1 and, in severe cases, a fire accident. Therefore, the ratio of the maximum gap width to the maximum diameter of the charging terminal 2 is preferably in the range of 0.01-0.7, and more preferably in the range of 0.05-0.5.

[0024] 4, the elastic support piece 3 is in the form of a straight segment, one end of which is connected to the inner wall of the cavity 11 and the other end of which is connected to the charging terminal 2. A straight segment elastic support piece 3 is easy to process and form, and has a large deformation amount after contact between the elastic support piece 3 and the inner wall of the cavity 11, so that a larger force is applied to the inner wall of the cavity 11 and better centering of the charging terminal 2. However, when the straight segment elastic support piece 3 is attached to the inner wall of the cavity 11, the expanded elastic support piece 3 must be retracted before attachment, which affects the elastic force of the elastic support piece 3 itself.

[0025] 5, the elastic support piece 3 is in the shape of an arc segment, one end of which is connected to the inner wall of the cavity or the charging terminal, and a tangential portion of which is connected to the charging terminal 2 or the inner wall of the cavity 11. The elastic support piece 3 of the arc segment has a tip with a small diameter, which acts as a guide when attached to the inner wall of the cavity 11 to prevent damage to the inner wall of the cavity 11 by the tip of the elastic support piece 3.

[0026] 6, the elastic support piece 3 has a curved segment shape, one end of which is connected to the inner wall of the cavity or the charging terminal, and the outermost part of which is connected to the charging terminal 2 or the inner wall of the cavity 11. The curved elastic support piece 3 contacts the inner wall of the cavity 11 at multiple points to form a stable support structure and achieve better centering of the charging terminal 2. In addition, the curved elastic support piece 3 also has a small-diameter tip that acts as a guide, allowing it to be easily and conveniently attached to the inner wall of the cavity 11.

[0027] In some embodiments, the supporting elastic piece 3 is mounted on the inner circumferential wall of the cavity 11 or the charging terminal 2 , and the central part of the supporting elastic piece 3 protrudes and contacts the charging terminal 2 or the inner circumferential wall of the cavity 11 .

[0028] In some embodiments, the elastic supporting piece 3 has a circular, elliptical, polygonal, flat, E-shaped, F-shaped, H-shaped, K-shaped, L-shaped, T-shaped, U-shaped, V-shaped, W-shaped, X-shaped, Y-shaped, Z-shaped, semicircular, arc-shaped, or wavy cross section in the radial direction of the charging terminal 2. The elastic supporting piece 3 has a variety of cross-sectional shapes, which broadens the designer's options and allows the selection of suitable materials for various usage environments.

[0029] In some embodiments, the support elastic piece 3 is formed in at least three pieces.

[0030] In some embodiments, the elastic support pieces 3 are uniformly arranged in the circumferential direction of the charging terminal 2. The uniformly arranged elastic support pieces 3 apply uniform pressure to the inner peripheral wall of the cavity 11, and position the charging terminal 2 in the center of the cavity 11 during insertion.

[0031] In some embodiments, the elastic support piece 3 has a minimum inner diameter in its natural state that is equal to or smaller than the minimum outer diameter of the charging terminal 2. The elastic support piece 3 has a minimum inner diameter in its natural state that is equal to or smaller than the minimum outer diameter of the charging terminal 2 when it is in its expanded state before being attached.

[0032] In some embodiments, as shown in FIG. 12, the supporting elastic piece 3 is brought into contact with the charging terminal 2 and applies a pressure of 0.5N-95N to the charging terminal 2.

[0033] In order to verify the effect of the pressure applied to the charging terminal 2 by the elastic support piece 3 on the contact resistance and insertion / removal after a mating terminal with a large eccentricity is inserted, the inventors used charging inlets 1 and charging terminals 2 of the same dimensions and specifications, and performed mating with charging terminals 2 with terminals at the mating insertion end of the same eccentricity based on the pressure applied to the charging terminal 2 by different elastic support pieces 3, and tested the contact resistance between the terminals after mating and the rate at which mating terminals were successfully inserted after several insertion / removal experiments. The test results are shown in Table 2.

[0034] The contact resistance test method is as follows: Using a microresistance meter, place one end of the measuring end of the microresistance meter on the mating terminal and the other end on the charging terminal 2 (place them in the same position as the measuring end), and then read the contact resistance displayed on the microresistance meter. In this example, a contact resistance greater than 1 mΩ was determined to be poor.

[0035] The test method for the success rate of insertion was as follows: Each charging terminal with each pressure value applied to the charging terminal 2 by the elastic support piece 3 was inserted into 100 terminals with the same eccentricity, and the number of successful insertions was recorded. The ratio to the total was calculated and expressed as a percentage (%). In this example, an insertion success rate below 95% was judged to be poor. [Table 2]

[0036] As shown in Table 2, when the pressure applied to the charging terminal 2 by the elastic support piece 3 is less than 0.5N, the success rate of insertion is acceptable, but when the contact resistance between the insertion terminal and the charging terminal 2 exceeds 1mΩ, the contact resistance is too high. Also, when the pressure applied to the charging terminal 2 by the elastic support piece 3 exceeds 95N, the success rate of insertion falls below 95%, which cannot meet the needs of the application. Therefore, it is preferable that the pressure applied to the charging terminal 2 by the elastic support piece 3 be 0.5N-95N.

[0037] 13 , the charging inlet 1 further includes a ring 4, which is fitted onto the elastic support piece 3, and the ring 4 and the elastic support piece 3 form an abutment portion that is fixed to the inner wall of the cavity 11. The abutment portion is located between both ends of the elastic support piece 3, with one end of the elastic support piece 3 contacting the inner wall of the cavity 11 or the charging terminal 2 and the other end contacting the charging terminal 2 or the inner wall of the cavity 11, and both ends of the elastic support piece 3 applying pressure to the inner wall of the cavity 11 or the charging terminal 2.

[0038] 13 , the ratio of the length from the contact portion to the end where the elastic support piece 3 leaves the charging terminal 2 to the length from the contact portion to the end where the elastic support piece 3 contacts the charging terminal 2 is 0.3-1.5. If this ratio is too small, the pressure applied to the charging terminal 2 by the elastic support piece 3 will be too small, and automatic centering will not be achieved efficiently. If this ratio is too large, the pressure applied to the charging terminal 2 by the elastic support piece 3 will be too large, and the charging terminal 2 will be fixed in the center position of the cavity 11, making it difficult for misalignment to occur. When installing mating terminals with different eccentricities, mating terminals with large eccentricities cannot be inserted.

[0039] In order to verify the effect on contact resistance and insertion / removal after inserting a mating terminal with large eccentricity due to the ratio of the length from the abutment part to the end where the support elastic piece 3 leaves the charging terminal and the length from the abutment part to the end where the support elastic piece 3 approaches the charging terminal, the inventors used charging inlet 1 and charging terminal 2 of the same dimensions and specifications, and inserted terminals with mating ends of the same eccentricity into charging terminal 2 based on different ratios of the length from the abutment part to the end where the support elastic piece 3 leaves the charging terminal and the length from the abutment part to the end where the support elastic piece 3 abuts the charging terminal. They tested the contact resistance between the terminals after mating and the rate at which mating terminals were successfully inserted in several insertion / removal experiments, and the test results are shown in Table 3.

[0040] The contact resistance test method is as follows: Using a microresistance meter, place one end of the measuring end of the microresistance meter on the terminal of the mating insertion end, and the other end on the charging terminal 2 (placed in the same position as the measuring end), and then read the contact resistance displayed on the microresistance meter. In this example, a contact resistance greater than 1 mΩ was considered defective.

[0041] The test method for the success rate of mating was as follows: Each charging terminal with a different pressure value applied to the charging terminal 2 by the elastic support piece 3 was mated with 100 mating terminals with the same eccentricity, and the number of successful matings was recorded. The ratio to the total number was calculated and expressed as a percentage (%). In this example, a success rate of mating below 95% was considered to be defective. [Table 3]

[0042] As shown in Table 3, when the ratio of the length from the contact point to the end where the elastic support piece 3 leaves the charging terminal to the length from the contact point to the end where the elastic support piece 3 abuts the charging terminal is less than 0.3, the success rate of insertion is acceptable, but the contact resistance between the insertion terminal and the charging terminal 2 exceeds 1 mΩ, which is too high. Furthermore, when the ratio of the length from the contact point to the end where the elastic support piece 3 leaves the charging terminal to the length from the contact point to the end where the elastic support piece 3 abuts the charging terminal is greater than 1.5, the success rate of insertion is less than 95%, failing to meet the application needs. Therefore, it is preferable that the ratio of the length from the contact point to the end where the elastic support piece 3 abuts the charging terminal be between 0.3 and 1.5.

[0043] In some embodiments, the charging terminal 2 comprises a terminal body 21 and a plurality of elastic sheets 22 spaced apart along the circumferential direction on the end surface of the terminal body 21, and the centers of the plurality of elastic sheets 22 are located in the insertion hole 23.

[0044] In some embodiments, the cross-sectional area of ​​the inner hole of the insertion hole 23 on one side closer to the terminal body 21 is larger than the cross-sectional area of ​​the inner hole on the other side away from the terminal body 21. After being inserted into the mating terminal, the mating terminal will swing under the action of an external force, driving the charging terminal 2 to offset, keeping the charging terminal 2 in an eccentric state and reducing the contact area between the terminals, thereby preventing excessive contact resistance and excessive temperature rise between the terminals, which could cause accidents such as fires in severe conditions.

[0045] In some embodiments, the thickness of one side of the opening of the insertion hole 23 of the elastic sheet 22 is greater than or equal to the thickness of the side closest to the terminal body 21. If the thickness of the elastic sheet 22 were the same, after the mating terminal is inserted, the inner surface of the elastic sheet 22 would be stuck to the outer surface of the mating terminal to form a wire contact, reducing the contact area. Therefore, by increasing the thickness of the tip of the elastic sheet 22 and reducing the inner angle of the tip of the elastic sheet 22, after the mating terminal is inserted, the flat surface of the inner tip of the expanded elastic sheet 22 comes into surface contact with the surface of the mating terminal, increasing the contact area between them and maintaining the electrical performance of the mating terminal.

[0046] 14, in some embodiments, the ratio of the maximum circumferential width of the elastic support piece 3 to the maximum circumferential width of the elastic sheet 22 is 0.1-1.6. If the ratio is below 0.1, the elasticity of the elastic support piece 3 is too low, and the pressure applied to the inner wall of the cavity 11 is too small, causing the charging terminal 2 to become eccentric. This reduces the contact area between the charging terminal 2 and the terminal at the mating insertion end of the charging inlet 1 and results in high contact resistance. If the ratio is above 1.6, the elasticity of the elastic support piece 3 is too high, and the pressure applied to the inner wall of the cavity 11 is too great. This fixes the charging terminal 2 in the center of the cavity 11, making it difficult for offset to occur. Therefore, when installing mating terminals with different eccentricities, the mating terminals with large eccentricities cannot be inserted.

[0047] In order to verify the effect of the ratio between the maximum circumferential width of the support elastic piece 3 and the maximum circumferential width of the elastic sheet 22 on the pressure applied to the inner wall of the cavity 11 by the support elastic piece 3 and the temperature rise of the charging terminal 2, the inventor used charging terminals 2 of the same dimensions and specifications and tested the pressure applied to the inner wall of the cavity 11 by the support elastic piece 3 and the temperature rise of the charging terminal 2 based on different ratios between the maximum circumferential width of the support elastic piece 3 and the maximum circumferential width of the elastic sheet 22, and recorded the results in Table 4.

[0048] The pressure is measured as follows: using a precision push-pull gauge, the measuring tip is brought into contact with the highest end of the elastic support piece 3, and then the elastic support piece 3 is pushed from the initial angle to the angle at which the inner peripheral wall of the cavity 11 is located, and the value indicated on the precision push-pull gauge is read. In this embodiment, a pressure of 5N-98N is considered a pass value, and a temperature rise of less than 10K is also considered a pass value. [Table 4]

[0049] As shown in Table 4, when the ratio of the maximum circumferential width of the elastic support piece 3 to the maximum circumferential width of the elastic sheet 22 exceeds 1.6, the pressure applied by the elastic support piece 3 to the inner wall of the cavity 11 exceeds 98 N, at which point the inner wall of the cavity 11 is subjected to too much pressure and is prone to damage, and the charging terminal 2 is fixed in the center of the cavity 11, making it difficult to create an offset. When installing mating terminals with different eccentricities, mating terminals with large eccentricities cannot be inserted. When the ratio of the maximum circumferential width of the elastic support piece 3 to the maximum circumferential width of the elastic sheet 22 is less than 0.1, the pressure applied by the elastic support piece 3 to the inner wall of the cavity 11 falls below 5 N, at which point the charging terminal 2 will become eccentric, the contact area between the charging terminal 2 and the mating end terminal in the charging inlet 1 will be small, and the contact resistance will be too high. On the other hand, if the ratio of the maximum circumferential width of the elastic support piece 3 to the maximum circumferential width of the elastic sheet 22 is less than 0.1, the contact resistance of the charging terminal 2 increases, causing a temperature rise of more than 10 K, which in turn raises the temperature of the charging inlet and, in severe cases, could lead to a combustion accident. Therefore, it is desirable that the ratio of the maximum circumferential width of the elastic support piece 3 to the maximum circumferential width of the elastic sheet 22 be between 0.1 and 1.6.

[0050] 10, the elastic support piece 3 is provided on the inner peripheral wall of the cavity 11, and the minimum diameter of the inner peripheral surface of the elastic support piece 3 is equal to or smaller than the minimum outer diameter of the elastic sheet 22. The elastic support piece 3 applies pressure to the charging terminal 2, keeping the charging terminal 2 in the center of the cavity 11 during insertion.

[0051] In some embodiments, as shown in FIG. 11, the supporting elastic piece 3 is brought into contact with the elastic sheet 22 and applies a pressure of 0.5-95N to the elastic sheet 22.

[0052] To verify the effect of pressure applied to elastic sheet 22 by elastic support piece 3 on the contact resistance and insertion / removal status after inserting a mating terminal with large eccentricity, the inventors used charging inlet 1 and charging terminal 2 of the same dimensions and specifications, and inserted mating terminals and charging terminal 2 with the same degree of eccentricity under different pressures applied to elastic sheet 22 by elastic support piece 3. They then tested the contact resistance between the terminals after insertion and the rate at which mating terminals were successfully inserted after several insertion / removal experiments, and the test results are shown in Table 5.

[0053] The contact resistance test method is as follows: Using a microresistance meter, place one end of the measuring end of the microresistance meter on the mating terminal and the other end on the charging terminal 2 (place them in the same position as the measuring end), and then read the contact resistance displayed on the microresistance meter. In this example, a contact resistance greater than 1 mΩ is considered defective.

[0054] The test method for the success rate of insertion is as follows: Each charging terminal with a different pressure value applied to the elastic sheet 22 by the support elastic piece 3 is inserted into 100 mating terminals with the same eccentricity, and the number of successful insertions is recorded. The ratio to the total number is calculated and expressed as a percentage (%). In this example, an insertion success rate below 95% is considered to be defective. [Table 5]

[0055] As shown in Table 5, when the pressure applied by the elastic support piece 3 to the elastic sheet 22 is less than 0.5N, the success rate of insertion is acceptable, but the contact resistance between the insertion terminal and the charging terminal 2 exceeds 1mΩ, which is too high. Also, when the pressure applied by the elastic support piece 3 to the elastic sheet 22 exceeds 95N, the success rate of insertion falls below 95%, which cannot meet the needs of the application. Therefore, it is preferable that the pressure applied by the elastic support piece 3 to the elastic sheet 22 be 0.5N-95N.

[0056] In some embodiments, the support elastic piece 3 is attached to the inner peripheral wall of the cavity 11 by one or more of ultrasonic welding, laser welding, electron beam welding, hot pressing welding, screwing, crimping, engaging, joining, and gluing.

[0057] 9, a groove is provided on the outer periphery of the elastic support piece 3, and the charging inlet 1 further includes an elastic sheath 31 fitted into the groove. The elastic sheath 31 can prevent scratches on the surface of the charging terminal 2 caused by the edge of the elastic support piece 3. On the other hand, if the elastic support piece 3 is not elastic enough to meet the pressure applied to the charging terminal 2, the elastic sheath 31 provides additional contraction force to increase the pressure applied to the charging terminal 2 by the elastic support piece 3.

[0058] In some embodiments, the elastic sheath 31 is an elastic rubber ring or a spring ring.

[0059] In some embodiments, the support elastic piece 3 and the charging terminal 2 are integrally molded. When integrally molded, the strength is high and, more importantly, the attachment can be performed after intensive processing, which greatly improves the attachment efficiency.

[0060] In some embodiments, the elastic support piece 3 is provided on the end surface of the terminal body 21 and is spaced apart from the center of the elastic sheet 22. The elastic support piece 3 is provided on the end surface of the terminal body 21, which simplifies processing and supports the charging terminal in the center of the cavity of the charging inlet, allowing the mating terminal to be directly and completely matingly inserted into contact with the charging terminal 2 without being misaligned from the axis when inserted, reducing the contact resistance of the mating terminal and improving the electrical performance of the charging inlet.

[0061] In some embodiments, the support resilient piece 3 is attached to the terminal body 21 by one or more of resistance welding, friction welding, ultrasonic welding, arc welding, laser welding, electron beam welding, pressure diffusion welding, magnetic induction welding, threading, crimping, engaging, splicing, or adhesive bonding.

[0062] 7, one end of the elastic support piece 3 is attached to the outer periphery of the elastic sheet 22, and the other end is in contact with the inner circumferential wall of the cavity 11. After the mating terminal is inserted, the elastic support piece 3 is brought into contact with the inner wall of the cavity 11, resulting in a large deformation amount, which can apply a larger force to the inner wall of the cavity 11 and achieve better centering of the charging terminal 2.

[0063] In some embodiments, the maximum outer diameter of the elastic support piece 3 in its natural state is equal to or greater than the maximum outer diameter of the inner peripheral wall of the cavity 11. In its natural state, the elastic support piece 3 is in an expanded state before being attached, and in its unforced state, its maximum outer diameter is equal to or greater than the maximum outer diameter of the inner peripheral wall of the cavity 11. After being attached, the elastic support piece 3 is in a compressed state and can generate pressure on the inner peripheral wall of the cavity 11.

[0064] 8, both ends of the elastic support piece 3 are attached to the outer periphery of the elastic sheet 22, and the center of the elastic support piece 3 protrudes to contact the inner periphery of the cavity 11. The protruding center of the elastic support piece 3 applies more uniform pressure to the cavity 11, providing better rebound resilience and better coaxiality after the mating terminal and the charging terminal 2 are mated.

[0065] In some embodiments, the maximum outer diameter of the elastic support piece 3 in its natural state is equal to or greater than the maximum outer diameter of the inner peripheral wall of the cavity 11. In its natural state, the elastic support piece 3 is in an expanded state before being attached, and in its unforced state, its maximum outer diameter is equal to or greater than the maximum outer diameter of the inner peripheral wall of the cavity 11. After being attached, the elastic support piece 3 is in a compressed state and can generate pressure on the inner peripheral wall of the cavity 11.

[0066] In some embodiments, the elastic support piece 3 contacts the inner wall of the cavity 11 and applies a pressure of 0.5N-100N to the inner wall of the cavity 11. If the pressure applied to the inner wall of the cavity 11 by the elastic support piece 3 is too small, the charging terminal 2 will be eccentric, the contact area between the charging terminal 2 and the mating terminal in the charging inlet 1 will be small, and the contact resistance will be too high. If the pressure applied to the inner wall of the cavity 11 by the elastic support piece 3 is too large, the charging terminal 2 will be fixed in the center of the cavity 11, making it difficult for offset to occur. When installing mating terminals with different eccentricities, the mating terminal with a large eccentricity will not be able to be inserted.

[0067] To verify the effect of the pressure applied to the inner wall of the cavity 11 by the elastic support piece 3 on the contact resistance and insertion / removal status after inserting a mating terminal with large eccentricity, the inventors used a charging inlet 1 and a charging terminal 2 of the same dimensions and specifications, and paired a terminal with the same degree of eccentricity with the charging terminal 2 based on the respective pressures applied to the inner wall of the cavity 11 by the elastic support piece 3. They then tested the contact resistance between the terminals after each pairing and the rate at which the mating terminals were successfully inserted after several insertion / removal experiments, and the test results are shown in Table 6.

[0068] The contact resistance test method is as follows: Using a microresistance meter, place one end of the measuring end of the microresistance meter on the mating terminal and the other end on the charging terminal 2 (place them in the same position as the measuring end), and then read the contact resistance displayed on the microresistance meter. In this example, a contact resistance greater than 1 mΩ is considered defective.

[0069] The test method for the success rate of mating is as follows: Each charging terminal with a different pressure value applied to the inner wall of the cavity 11 by the elastic support piece 3 is mated with 100 mating terminals with the same eccentricity, and the number of successful matings is recorded. The ratio to the total number is calculated and expressed as a percentage (%). In this example, a success rate of mating below 95% is considered to be defective. [Table 6]

[0070] As shown in Table 6, when the pressure applied to the inner wall of the cavity 11 by the elastic support piece 3 is less than 0.5N, the success rate of insertion is acceptable, but the contact resistance between the insertion terminal and the charging terminal 2 exceeds 1mΩ, which is too high. Also, when the pressure applied to the inner wall of the cavity 11 by the elastic support piece 3 exceeds 100N, the success rate of insertion falls below 95%, which cannot meet the needs of the application. Therefore, it is preferable that the pressure applied to the inner wall of the cavity by the elastic support piece 3 be 0.5N-100N.

[0071] In some embodiments, the supporting elastic piece 3 is attached to the elastic sheet 22 by one or more of resistance welding, friction welding, ultrasonic welding, arc welding, laser welding, electron beam welding, pressure diffusion welding, magnetic induction welding, screwing, crimping, engaging, splicing, or gluing.

[0072] Ultrasonic welding refers to the method of transmitting high frequency vibration waves to the surfaces of two objects to be welded, and then applying pressure to rub the surfaces of the two objects against each other to form a fusion bond between molecular layers.

[0073] Resistance welding is a welding method that uses a strong current to generate heat through the contact point between the electrode and the workpiece, resulting in welding.

[0074] Magnetic induction welding is a method in which two workpieces are welded together by applying a strong pulsed magnetic field, causing a sudden, high-speed collision, and then applying high pressure waves to the surface of the materials, causing the atoms of the two materials to collide within the interatomic distance, forming a stable metallurgical bond at the interface.It is a type of solid-state cold welding that can weld conductive metals with similar or dissimilar properties.

[0075] Arc welding is a method of joining metals by using an electric arc as a heat source and utilizing the physical phenomenon of air discharge to convert electrical energy into the thermal and mechanical energy required for welding. The main methods include shielded arc welding, submerged arc welding, and gas-shielded welding.

[0076] Pressure welding refers to a welding method in which pressure is applied to the welded parts to bring the joining surfaces into close contact and generate a certain amount of plastic deformation.

[0077] Electron beam welding refers to the use of an accelerated and focused electron beam to impact the welding surface in a vacuum or non-vacuum to melt and weld the workpieces.

[0078] Laser welding is an efficient and precise welding method that uses a high-energy density laser beam as a heat source.

[0079] Friction welding is a method of welding workpieces by plastically deforming them with pressure, using the heat generated by friction between the contact surfaces of the workpieces as a heat source.

[0080] The screwing method means that the supporting elastic piece 3 and the terminal body 21 or the elastic sheet 22 each have a screw structure and are screwed together or connected by a separate stud and nut. Since the screwing method is detachable, it can be repeatedly assembled and disassembled, and is advantageous for use in situations where frequent disassembly is required.

[0081] The crimping method refers to a production process in which the support elastic piece 3 and the terminal body 21 or elastic sheet 22 are attached and then pressed together using a crimping machine. Crimping is suitable for mass production and has the advantage of being able to quickly produce many products with stable quality using interlock terminals and an automatic crimping machine.

[0082] The engagement method refers to the use of a member such as a clamp to engage the support elastic piece 3 with the terminal body 21 or the elastic sheet 22. This engagement does not require complicated equipment and can be connected using a tool, which has the advantage of being applicable to situations such as maintenance.

[0083] The joining method refers to the provision of corresponding grooves and protrusions on the supporting elastic piece 3 or the terminal body 21 (or elastic sheet 22), which are attached and connected by mortise and tenon joints or joints. The joining method has the advantage of being stable and removable.

[0084] In some embodiments, the maximum diameter of the outer periphery of the elastic support piece 3 in its natural state is equal to or greater than the maximum diameter of the cavity 11 .

[0085] In some embodiments, the elastic support piece 3 contacts the inner wall of the cavity 11 and applies pressure to the inner wall of the cavity 11. The pressure applied to the inner wall of the cavity is 0.5N-100N. If the elastic support piece 3 only contacts the inner wall of the cavity 11 without applying pressure, after the mating terminal and the charging terminal 2 are inserted and installed, the mating terminal will vibrate due to the action of an external force, driving the charging terminal 2 to create an offset. The elastic force of the elastic support piece 3 after deformation will not allow the charging terminal 2 to return to its centered position. The offset will not be restored and the elastic support piece 3 will not spring back until the deformation stress is released, causing the charging terminal 2 to remain eccentric. The charging terminal 2 in the charging inlet 1 and the terminal at the mating end to be non-concentric will result in a small contact area between the terminals, resulting in high contact resistance and even excessive temperature rise between the terminals, which in severe cases may lead to accidents such as fires.

[0086] Similarly, if the pressure applied to the inner wall of cavity 11 by elastic support piece 3 is too small, charging terminal 2 will become eccentric, the contact area between charging terminal 2 and the mating terminal in charging inlet 1 will be small, and contact resistance will be too high. Also, if the pressure applied to the inner wall of cavity 11 by elastic support piece 3 is too large, charging terminal 2 will be fixed in the center of cavity 11, making it difficult to create an offset, and when mating terminals with different eccentricities are installed, mating terminals with large eccentricities cannot be inserted.

[0087] To verify the effect of the pressure applied by the elastic support piece 3 to the inner wall of the cavity 11 on the contact resistance and insertion / removal status after inserting a mating terminal with large eccentricity, the inventors used a charging inlet 1 and a charging terminal 2 of the same dimensions and specifications, and paired a terminal with the same degree of eccentricity with the charging terminal 2 based on the respective pressures applied by the elastic support piece 3 to the inner wall of the cavity 11. They then tested the contact resistance between the terminals after each pairing and the rate at which the mating terminals were successfully inserted after several insertion / removal experiments, and the test results are shown in Table 7.

[0088] The contact resistance test method is as follows: Using a microresistance meter, place one end of the measuring end of the microresistance meter on the mating terminal and the other end on the charging terminal 2 (place them in the same position as the measuring end), and then read the contact resistance displayed on the microresistance meter. In this example, a contact resistance greater than 1 mΩ is considered defective.

[0089] The test method for the success rate of mating was as follows: Each charging terminal with a different pressure value applied to the inner wall of the cavity 11 by the elastic support piece 3 was mated with 100 terminals with the same eccentricity, and the number of successful matings was recorded. The ratio to the total number was calculated and expressed as a percentage (%). In this example, a success rate of mating below 95% was considered to be defective. [Table 7]

[0090] As shown in Table 7, when the pressure applied by the elastic support piece 3 to the inner wall of the cavity 11 is less than 0.5N, the success rate of insertion is acceptable, but the contact resistance between the insertion terminal and the charging terminal 2 exceeds 1mΩ, which is too high. Furthermore, when the pressure applied by the elastic support piece 3 to the inner wall of the cavity 11 exceeds 100N, the success rate of insertion falls below 95%, which cannot meet the needs of the application. Therefore, it is preferable that the pressure applied by the elastic support piece 3 to the inner wall of the cavity be 0.5N-100N.

[0091] In some embodiments, the material of the elastic sheet 22 / or the supporting elastic piece 3 contains a tellurium copper alloy, so that the charging terminal 2 has good conductivity and machinability, which ensures electrical performance and improves processability.

[0092] Furthermore, the tellurium content in tellurium copper alloy is 0.1%-5%, which not only maintains electrical conductivity but also provides good elasticity.

[0093] To verify the effect of the tellurium content in the tellurium-copper alloy of the elastic sheet 22 / or the elastic supporting piece 3 on the electrical conductivity of the insertion site between the charging terminal 2 and the insertion terminal, the inventors conducted tests using 10 identical charging terminals 2. Each charging terminal 2 had the same dimensions and the same number of elastic supporting pieces 3. The elastic sheet 22 and the elastic supporting pieces 3 were both made of tellurium-copper alloy, with tellurium contents of 0.05%, 0.1%, 0.2%, 0.5%, 0.8%, 1.2%, 2%, 3%, 5%, 6%, and 7%, respectively. After inserting the charging terminal 2 into the insertion terminal and passing a current through the insertion structure, the electrical conductivity of the corresponding insertion site was measured. In this example, the electrical conductivity should be above 99%. The test results are shown in Table 8. [Table 8]

[0094] As shown in Table 8, when the tellurium content is below 0.1% or above 5%, the conductivity is significantly reduced and cannot meet the desired value. When the tellurium content is above 0.2% but below 1.2%, the conductivity is the best. When the tellurium content is above 1.2% but below 5%, the conductivity meets the desired value, but tends to gradually decrease, and the conductivity also decreases. Therefore, it is recommended to use a tellurium copper alloy with a tellurium content of 0.1%-5%.

[0095] In some embodiments, the material of the elastic sheet 22 and / or the supporting elastic piece 3 includes a beryllium copper alloy, and the beryllium content in the beryllium copper alloy is 0.05%-5%. By including beryllium in the material of the elastic sheet 22 and / or the supporting elastic piece 3, the material of the elastic sheet 22 and / or the supporting elastic piece 3 has high hardness, elastic limit, fatigue limit and wear resistance, as well as good corrosion resistance, heat transfer and electrical conductivity, and will not generate sparks when impacted.

[0096] To verify the effect of the beryllium content in the beryllium-copper alloy of the elastic sheet 22 / or the elastic supporting piece 3 on the electrical conductivity of the insertion site between the charging terminal 2 and the insertion terminal, the inventors conducted tests using 10 identical charging terminals 2. Each charging terminal 2 had the same dimensions, and the same number of elastic supporting pieces 3 per charging terminal 2. The elastic sheet 22 and the elastic supporting pieces 3 both contained beryllium, with beryllium contents of 0.03%, 0.05%, 0.1%, 0.2%, 1%, 1.8%, 3%, 3.5%, 5%, and 6%, respectively. After inserting the charging terminal 2 into the insertion terminal and passing a current through the insertion structure, the electrical conductivity of the corresponding insertion site was measured. In this example, the electrical conductivity should be above 99%. The test results are shown in Table 9. [Table 9]

[0097] As shown in Table 9, when the beryllium content is below 0.05% or above 5%, the conductivity is significantly reduced and cannot meet actual needs. When the beryllium content is between 0.1% and 3.5%, the conductivity is optimal. Therefore, the beryllium content in the material of the elastic sheet 22 and / or the supporting elastic piece 3 is preferably between 0.05% and 5%. Most preferably, the beryllium content in the beryllium-copper alloy is between 0.1% and 3.5%.

[0098] In a preferred embodiment, the material of elastic sheet 22 and / or elastic supporting piece 3 includes a phosphorus bronze alloy, and the phosphorus content in the phosphorus bronze alloy is 0.01% to 1.5%. Phosphor bronze has good corrosion resistance and abrasion resistance, which ensures good contact between charging terminal 2 and elastic supporting piece 3, good elasticity, and excellent machining performance, which can shorten the part processing time.

[0099] To verify the effect of the phosphorus content in the phosphorus bronze alloy of the elastic sheet 22 / or the elastic supporting piece 3 on the conductivity of the insertion site between the charging terminal 2 and the insertion terminal, the inventors conducted tests using 10 identical charging terminals 2. Each charging terminal 2 had the same dimensions and the same number of elastic supporting pieces 3. The elastic sheet 22 and the elastic supporting pieces 3 both contained phosphorus, with phosphorus contents of 0.001%, 0.005%, 0.01%, 0.05%, 0.1%, 0.5%, 1%, 1.5%, 2%, and 2.5%, respectively. After inserting the charging terminal 2 into the insertion terminal and passing a current through the insertion structure, the conductivity of the corresponding insertion site was measured. In this example, the conductivity should be above 99%. The test results are shown in Table 10. [Table 10]

[0100] As shown in Table 10, when the phosphorus content is below 0.01% or above 1.5%, the electrical conductivity is significantly reduced and cannot meet actual needs. When the phosphorus content is between 0.05% and 0.5%, the electrical conductivity is optimal. Therefore, the phosphorus content in phosphor bronze alloys is preferably between 0.01% and 1.5%. The most preferred phosphorus content is between 0.05% and 0.5%.

[0101] In the best embodiment, the material of the elastic sheet 22 and / or the supporting elastic piece 3 includes a lead-brass alloy, and the lead content of the lead-brass alloy is 0.1% to 5%. The lead-brass alloy has high strength, a dense and uniform structure, good corrosion resistance, and excellent mechanical workability such as cutting and drilling.

[0102] To verify the effect of the lead content in the lead-brass alloy of the elastic sheet 22 / or the elastic supporting piece 3 on the electrical conductivity of the charging terminal 2 and the insertion terminal, the inventors conducted tests using 10 identical charging terminals 2. Each charging terminal 2 had the same dimensions and the same number of elastic supporting pieces 3. Both the elastic sheet 22 and the elastic supporting pieces 3 contained lead, with lead contents of 0.05%, 0.5%, 1%, 2%, 3%, 4%, 5%, 6%, and 7%, respectively. After inserting the charging terminal 2 and the insertion terminal and passing a current through the insertion structure, the electrical conductivity of the corresponding insertion portion was measured. In this example, electrical conductivity of over 99% is desirable, and the test results are shown in Table 11. [Table 11]

[0103] As shown in Table 11, when the lead content is below 0.1% or above 5%, the conductivity is significantly reduced and cannot meet actual needs. When the lead content is between 1% and 3%, the conductivity is optimal. Therefore, the lead content of lead brass alloys is preferably between 0.1% and 5%. The most desirable lead content is 1% to 3%.

[0104] In some embodiments, the copper content of the materials of the elastic support piece 3 and the charging terminal 2 does not match. Because the main purpose of the elastic support piece 3 is to apply pressure to the inner wall of the charging terminal 2 or the cavity 11, the copper content of the elastic support piece 3 mainly serves to improve the elasticity of the elastic support piece 3 itself and its wear resistance when rubbing against the inner wall of the charging terminal 2 or the cavity 11. Because the charging terminal 2 mainly serves to conduct current after being inserted into the mating terminal, the copper content of the charging terminal 2 mainly serves to improve the conductivity of the charging terminal 2 and its scratch resistance when inserted into the mating terminal. Therefore, it is preferable that the copper content of the materials of the elastic support piece 3 and the charging terminal 2 do not match.

[0105] In some embodiments, the elastic sheet 22 and / or the supporting elastic piece 3 may be provided with a plating layer on at least a portion thereof to improve corrosion resistance and electrical conductivity, increase the number of bonding times, and better extend the service life of the insertion structure. The plating layer may cover the entire surface of the elastic sheet 22 and / or the supporting elastic piece 3, or may cover only a portion of the surface of the elastic sheet 22 and / or the supporting elastic piece 3.

[0106] In the best embodiment, the materials of the plating layers do not match between the elastic sheet 22 and the elastic support piece 3. Since the elastic sheet 22 and the elastic support piece 3 are prone to contact corrosion and micro-corrosion in the actual working environment, plating layers are provided on the elastic sheet and the elastic support piece to extend their service lives.

[0107] Contact corrosion, also known as galvanic corrosion, is electrochemical corrosion that occurs when two dissimilar metals come into contact with each other and are simultaneously placed in an electrolyte. Because they form a self-starting battery, the active and anode metals corrode. The charging terminal and mating terminal are in contact for long periods of time, making contact corrosion more likely. Therefore, plating layers are made of inert materials, which are often expensive but offer strong protection against electrochemical corrosion.

[0108] Fretting corrosion is a type of fretting wear in which corrosion plays an important role. Typically, the amount of material lost from corrosion-resistant materials is extremely small. However, under fretting corrosion conditions, the protective film formed on the surface of the corrosion-resistant material is scraped away by the mechanical action of fretting friction, exposing new, chemically active metal on the surface. This new metal reacts with the surrounding medium, forming a new surface film of a certain thickness according to a set pattern, which is then scraped away by mechanical action, in a cyclical fashion. This combined mechanical and corrosive action results in significant material loss from the surface. Regarding the principle of fretting corrosion, a plating layer with a certain hardness is formed on the supporting elastic piece. Unless the plating layer is hard enough, it will be able to withstand repeated fretting friction during micro-vibrations and avoid exposing the supporting elastic piece itself. Therefore, it is preferable to use different materials for the plating layers of the charging terminal and the supporting elastic piece, depending on their respective characteristics.

[0109] In a preferred embodiment, the thicknesses of the plating layers on the elastic sheet 22 and the supporting elastic piece 3 are not the same. The ratio of the thickness of the plating layer on the elastic sheet 22 to the thickness of the plating layer on the supporting elastic piece 3 is 3% or more. The thickness of the different plating layers can be selected according to needs, such as an assembly method with a plating layer thickness that saves costs, an assembly method with better wear resistance, or an assembly method that takes into account each factor and is optimal for the actual operating environment. On the other hand, plating layers with unequal thicknesses change the corrosion path of external corrosion from linear corrosion when the thicknesses are consistent to oblique corrosion when the thicknesses are not the same, thereby increasing the distance of the corrosion path of external corrosion and better protecting the internal substrate and extending the service life of the elastic sheet 22 and the supporting elastic piece 3.

[0110] To verify the effect of the thickness ratio of the plating layer on the elastic sheet 22 to the thickness ratio of the plating layer on the supporting elastic piece 3 on the wear resistance of the charging terminal 2, the inventors used charging terminal 2 samples with the same specifications and materials but different thickness ratios of the plating layer on the elastic sheet 22 to the thickness ratio of the plating layer on the supporting elastic piece 3, and conducted a series of plugging / unplugging cycles and corrosion resistance time tests using charging inlets 1 of the same specifications. The experimental results are shown in Table 11.

[0111] For the number of insertions and removals in Table 12, each charging terminal 2 was fixed to a test stand and a mechanical device was used to simulate insertion and removal of the corresponding insertion terminal. After 100 insertions and removals, the damage to the plating layer on the surface of the charging terminal 2 was observed. If scratches appeared on the plating layer on the terminal surface and the material of the terminal itself was exposed, the experiment was stopped and the number of insertions and removals at that time was recorded. In this example, a product was deemed defective if the number of insertions and removals was less than 8,000.

[0112] The corrosion resistance time test in Table 12 was performed as follows: charging terminal 2 was placed in a salt spray test box, and salt water was sprayed at various positions on charging terminal 2. The charging terminal was then removed and washed every 20 hours, and the surface corrosion status was observed. This constituted one cycle. When the surface corrosion area of ​​charging terminal 2 exceeded 10% of the total area, the test was stopped and the number of cycles at that time was recorded. In this example, a cycle count of less than 80 was deemed defective. [Table 12]

[0113] As shown in Table 12, when the thickness ratio of the plating layer on elastic sheet 22 to the plating layer on supporting elastic piece 3 is below 3%, the number of insertions and removals of charging terminal 2 and the number of cycles in the corrosion resistance test are both poor, making the plating layer more susceptible to damage and reducing the electrical performance of the charging terminal. When the thickness ratio of the plating layer on elastic sheet 22 to the plating layer on supporting elastic piece 3 is 3% or more, the number of insertions and removals of charging terminal 2 and the number of cycles in the corrosion resistance test both meet the experimental requirements. Therefore, it is desirable that the thickness ratio of the plating layer on elastic sheet 22 to the plating layer on supporting elastic piece 3 be 3% or more.

[0114] In some embodiments, a plating layer is provided on the outer peripheral wall of the charging terminal 2, but the materials of the plating layer on the outer peripheral wall of the charging terminal 2 and the plating layer on the surface of the supporting elastic piece 3 do not match. In an actual working environment, the outer peripheral wall of the charging terminal 2 and the supporting elastic piece 3 are prone to contact corrosion and micro-corrosion, respectively, so a plating layer is provided on the outer peripheral wall of the charging terminal 2 and the supporting elastic piece 3 to extend the service life of the elastic sheet and the supporting elastic piece.

[0115] Contact corrosion, also known as galvanic corrosion, is electrochemical corrosion that occurs when two dissimilar metals are in contact with each other and placed in an electrolyte at the same time. Because they form a spontaneously activated battery, the active and anode metals corrode. Contact corrosion is likely to occur because they maintain contact with the mating terminals for a long period of time. Therefore, plating layers are often made of inert materials, which are often expensive but have a strong ability to prevent electrochemical corrosion.

[0116] Fretting corrosion is a type of fretting wear in which corrosion plays a significant role. Typically, corrosion-resistant materials lose very little material during corrosion. However, under fretting corrosion conditions, the protective film formed on the surface of the corrosion-resistant material is scraped away by the mechanical action of fretting friction, exposing new, chemically active metal on the surface. This new metal reacts with the surrounding medium, forming a new surface film of a certain thickness according to a set pattern, which is then scraped away by mechanical action, in a cyclical fashion. This results in significant material loss from the surface due to the combined mechanical and corrosive effects. Regarding the principle of fretting corrosion, a plating layer with a certain hardness is formed on the supporting elastic piece. Unless the plating layer is hard enough, it will be unable to resist repeated fretting friction during micro-vibrations and avoid exposing the supporting elastic piece itself. Therefore, it is preferable to use different materials for the plating layers of the charging terminal and the supporting elastic piece, depending on their respective characteristics.

[0117] In some embodiments, a plating layer is provided on the outer peripheral wall of the charging terminal 2, and the plating layer on the outer peripheral wall of the charging terminal 2 and the plating layer on the surface of the supporting elastic piece 3 do not match in thickness. The thickness of the different plating layers can be selected according to needs, such as an assembly method with a plating layer thickness that saves costs, an assembly method with better wear resistance, or an assembly method that is optimal for the actual operating environment by taking each factor into consideration. On the other hand, the plating layers with unequal thicknesses change the corrosion path of external corrosion from linear corrosion when the thicknesses are consistent to oblique corrosion when the thicknesses are unequal, thereby increasing the corrosion path distance of external corrosion and better protecting the internal substrate and extending the service life of the elastic sheet 22 and the supporting elastic piece 3.

[0118] In some embodiments, the copper contents of the materials of the elastic support piece 3 and the elastic sheet 22 do not match. The elastic support piece 3 is primarily intended to apply pressure to the inner circumferential wall of the charging terminal 2 or the cavity 11, and the copper content of the elastic support piece 3 is primarily intended to improve the elasticity of the elastic support piece 3 itself and its abrasion resistance when rubbing against the inner circumferential wall of the charging terminal 2 or the cavity 11. The elastic sheet 22 is primarily intended to conduct current after being inserted into the mating insertion terminal, and the copper content of the elastic sheet 22 is primarily intended to improve the conductivity of the elastic sheet 22 and its scratch resistance when being inserted into the mating insertion terminal. Therefore, it is preferable that the copper contents of the materials of the elastic support piece 3 and the charging terminal 2 do not match.

[0119] In some embodiments, the material of the plating layer includes one or more of nickel, cadmium, manganese, zirconium, cobalt, tin, titanium, chromium, gold, silver, zinc, tin-lead alloy, silver-antimony alloy, palladium, palladium-nickel alloy, graphite silver, graphene silver, hard silver, and silver-gold-zirconium alloy.

[0120] Copper is an active metal that undergoes oxidation reactions with oxygen and water during use, so forming a plating layer from one or more inactive metals extends the service life of the charging terminal 2. Meanwhile, for metal contacts that are constantly being inserted and removed, plating the contacts with a good wear-resistant metal can significantly extend their service life. The contacts require good electrical conductivity, and the above metals have better conductivity and stability than copper or copper alloys, improving the electrical performance of the charging terminal 2 and extending its service life.

[0121] To verify the impact of different plating layer materials on the overall performance of the terminal, the inventors used the same specifications and materials to take charging terminal 2 samples with different plating layer materials and conducted a series of plug-and-unplug cycle and corrosion resistance time tests using charging inlet 1 of the same specifications. To demonstrate the advantages and disadvantages of the materials used and other commonly used plating materials, the inventors used tin, nickel, and zinc as the plating layer materials in the experiments. The experimental results are shown in Table 13.

[0122] For the number of insertions and removals in Table 13, each charging terminal 2 was fixed to a test stand and a mechanical device was used to simulate insertion and removal of the corresponding insertion terminal. After 100 insertions and removals, the damage to the plating layer on the surface of the charging terminal 2 was observed. If scratches appeared on the plating layer on the terminal surface and the material of the terminal itself was exposed, the experiment was stopped and the number of insertions and removals at that time was recorded. In this example, a number of insertions and removals below 8,000 was considered defective.

[0123] For the corrosion resistance time test in Table 13, charging terminal 2 was placed in a salt spray test box, and salt water was sprayed at various positions on charging terminal 2. Each 20-hour period was taken out and washed to observe the surface corrosion. When the corrosion area on the surface of charging terminal 2 exceeded 10% of the total area, the test was stopped and the number of cycles at that time was recorded. In this example, a cycle of less than 80 was deemed defective. [Table 13]

[0124] As shown in Table 13 above, when gold, silver, silver-antimony alloy, palladium, palladium-nickel alloy, graphite silver, graphene silver, hard silver, and silver-gold-zirconium alloy are used as plating layer materials, the experimental results generally exceed the standard values ​​and the performance is stable. When nickel, tin, tin-lead alloy, and zinc are used as plating layer materials, the experimental results also meet the requirements, so it is preferable to use one or more of gold, silver, nickel, tin, tin-lead alloy, zinc, silver-antimony alloy, palladium, palladium-nickel alloy, graphite silver, graphene silver, hard silver, and silver-gold-zirconium alloy as plating layer materials.

[0125] In some embodiments, the plating layer is applied by electroplating, electroless plating, magnetron sputtering, or vacuum plating.

[0126] Plating refers to the process of coating a metal surface with a thin layer of another metal or alloy using electrolytic principles.

[0127] Electroless plating refers to a deposition process that produces metals through a controllable oxidation-reduction reaction catalyzed by metals.

[0128] The magnetron sputtering method uses the interaction of a magnetic field and an electric field to make electrons spiral around the target surface, increasing the probability that the electrons will bombard the argon gas and generate ions, and the generated ions collide with the target surface under the action of the electric field, sputtering the target material.

[0129] The vacuum plating method refers to the deposition of metal and non-metal thin films on the surface of components by evaporation or sputtering under vacuum conditions.

[0130] In a preferred embodiment, the plating layer includes a base layer and a surface layer. The plating layer is formed by a multi-layer plating method. After processing, the elastic support piece 3 still has many slits and holes at the microscopic interface on the surface, which are the main cause of wear and corrosion of the elastic support piece 3 during use. In this embodiment, the surface of the elastic support piece 3 is first plated with a base layer to fill the slits and holes on the surface, flattening the surface of the elastic support piece 3. After the holes are removed, the surface layer is plated, resulting in a stronger and flatter bond. There are no slits or holes on the surface of the plating layer, which further improves the wear resistance, corrosion resistance, and electrical performance of the charging terminal 2 and greatly extends the service life of the charging terminal 2.

[0131] The base layer material includes one or more of gold, silver, nickel, tin, tin-lead alloy, and zinc, and the surface layer material includes one or more of gold, silver, nickel, tin, tin-lead alloy, silver-antimony alloy, palladium, palladium-nickel alloy, graphite silver, graphene silver, and silver-gold-zirconium alloy.

[0132] In another embodiment, the base layer is formed to a thickness of 0.01 μm to 12 μm. Preferably, the base layer is formed to a thickness of 0.1 μm to 9 μm.

[0133] In another embodiment, the surface layer is formed to a thickness of 0.5 μm to 50 μm, and preferably to a thickness of 1 μm to 35 μm.

[0134] To verify the effect of varying the thickness of the base plating layer on the overall performance of charging terminal 2, the inventors conducted a series of temperature rise and corrosion resistance time tests using charging terminals 2 with the same specifications, materials, different nickel-plated base layer thicknesses, and the same silver-plated surface layer thicknesses, and using mating terminals with the same specifications. The experimental results are shown in Table 14.

[0135] For the temperature rise test in Table 14, the same current is passed through the charging terminal 2 after insertion and the mating terminal, and the temperatures at the same positions on the insertion structure are measured in a sealed environment before and after the current is passed and the temperature is stabilized, and the absolute value of the difference is obtained. In this example, a temperature rise of more than 50 K is considered to be defective.

[0136] For the corrosion resistance time test in Table 14, charging terminal 2 was placed in a salt spray test box, and salt water was sprayed at various positions on charging terminal 2. The charging terminal was removed and washed every 20 hours, and the surface corrosion was observed. The test was stopped when the corrosion area on the surface of charging terminal 2 exceeded 10% of the total area, and the number of cycles at that time was recorded. In this example, a cycle of less than 80 was considered defective. [Table 14]

[0137] As shown in Table 14, when the thickness of the nickel plating layer on the base layer is less than 0.01 μm, the temperature rise of the insertion structure is acceptable, but the plating layer is too thin, resulting in fewer than 80 corrosion-resistant cycles for the charging terminal 2, failing to meet the terminal performance requirements. This significantly affects the overall performance and lifespan of the insertion structure, and in severe cases, can rapidly shorten the lifespan, render the structure ineffective, and even cause a fire. When the nickel plating layer on the base layer is more than 12 μm, the thick base plating layer prevents the heat generated by the insertion structure from being dissipated, resulting in poor temperature rise for the insertion structure. Furthermore, a thick plating layer can easily peel off from the surface, reducing the number of corrosion-resistant cycles. Therefore, the thickness of the nickel plating layer on the base layer is preferably between 0.01 μm and 12 μm.

[0138] Preferably, when the thickness of the plating layer of the base layer is 0.1 μm to 9 μm, the overall effect of the temperature rise and corrosion resistance of the insertion structure is better, and in order to improve the safety, reliability and practicality of the product itself, it is preferable that the thickness of the plating layer of the base layer is 0.1 μm to 9 μm.

[0139] To verify the effect of varying the thickness of the surface plating layer on the overall performance of the insertion structure, the inventors conducted a series of temperature rise and corrosion resistance time tests on pairs of insertion terminals with the same specifications, using charging terminal samples 2 with the same specifications, material, nickel base layer thickness, and different silver surface layer thickness. The experimental method was the same as the above-mentioned experimental method, and the experimental results are shown in Table 15. [Table 15]

[0140] As shown in Table 15, when the thickness of the silver plating layer on the surface layer is less than 0.5 μm, the temperature rise of the insertion structure is acceptable, but the plating layer is too thin, resulting in fewer than 80 corrosion-resistant cycles of the charging terminal 2, failing to meet the performance requirements of the charging terminal 2. This significantly affects the overall performance and lifespan of the insertion structure, and in severe cases, it can rapidly shorten the lifespan, render the structure ineffective, and even cause a fire. When the thickness of the silver plating layer on the base layer is more than 50 μm, the thick base layer prevents the heat generated by the terminal from being dissipated, resulting in poor temperature rise. A thick plating layer can easily peel off from the terminal surface, reducing the number of corrosion-resistant cycles. Furthermore, because the metal used for the surface plating layer is expensive, using a thick plating layer results in poor performance and is useless. Therefore, the thickness of the silver plating layer on the surface layer is preferably between 0.1 μm and 50 μm. Preferably, when the thickness of the surface plating layer is 1 μm to 35 μm, the integrated effect of temperature rise and corrosion resistance of the insertion structure is better, so in order to improve the safety, reliability and practicality of the product itself, the thickness of the surface plating layer is preferably 1 μm to 35 μm.

[0141] The present application provides a vehicle equipped with a charging inlet in which the terminals are centered with high precision. The charging inlet is as shown in Figure 15.

[0142] The above are merely some of the best examples of the present application, and those skilled in the art can make various changes or modifications to the examples of the present application based on the contents disclosed in the application documents without departing from the spirit and scope of the present application.

Claims

1. A charging inlet with terminals that are centered with high precision, a cavity for accommodating a charging terminal is provided in the charging inlet, a gap exists between an inner peripheral wall of the cavity and an outer peripheral wall of the charging terminal, a support elastic piece is provided in the gap, the support elastic piece is arranged along a circumferential direction of the charging terminal, and the support elastic piece is configured to restrict misalignment between an axis of the charging terminal and an axis of the cavity; the charging inlet further comprises a ring that is fitted to the elastic support piece and fixed to an inner wall of the cavity while forming an abutment with the elastic support piece, wherein a ratio of a length from the abutment to an end of the elastic support piece that is away from the charging terminal to a length from the abutment to an end of the elastic support piece that is abutted against the charging terminal is 0.3-1.5; The charging terminal comprises a terminal body and a plurality of elastic sheets provided on an end surface of the terminal body and spaced apart in the circumferential direction, the centers of the elastic sheets being configured as insertion holes, the support elastic pieces being provided on the end surface of the terminal body and spaced apart in the centers of the elastic sheets, and the ratio of the maximum circumferential width of the support elastic pieces to the maximum circumferential width of the elastic sheets is 0.1-1.

6.

2. 2. The charging inlet according to claim 1, wherein the ratio of the maximum width of the gap to the maximum diameter of the charging terminal is in the range of 0.01-0.

7.

3. The charging inlet according to claim 1, characterized in that the supporting elastic piece is formed in the shape of a straight segment, one end of the straight segment is connected to the inner peripheral wall of the cavity, and the other end of the straight segment is connected to the charging terminal.

4. The charging inlet according to claim 1, characterized in that the supporting elastic piece is formed in an arc segment shape, one end of the arc segment is connected to the inner peripheral wall of the cavity or the charging terminal, and a tangential portion of the arc segment is connected to the charging terminal or the inner peripheral wall of the cavity.

5. The charging inlet according to claim 1, characterized in that the supporting elastic piece is formed in a curved segment shape, one end of the curved segment is connected to the inner wall of the cavity or the charging terminal, and the other end of the curved segment is connected to the charging terminal or the inner wall of the cavity.

6. The charging inlet described in claim 1, characterized in that both ends of the support elastic piece are connected to the inner wall of the cavity or the charging terminal, and the support elastic piece has a protruding central portion that is connected to the charging terminal or the inner wall of the cavity.

7. 2. The charging inlet according to claim 1, wherein the supporting elastic piece contacts the charging terminal and applies a pressure of 0.5N-95N to the charging terminal.

8. 2. The charging inlet according to claim 1, wherein a groove is provided on the outer periphery of the supporting elastic piece, and the charging inlet further comprises an elastic sheath to be fitted into the groove.

9. 2. The charging inlet according to claim 1, wherein the supporting elastic piece is integrally molded with the charging terminal.

10. 2. The charging inlet according to claim 1, wherein the support elastic piece contacts the inner peripheral wall of the cavity and applies a pressure of 0.5N-100N to the inner peripheral wall of the cavity.

11. 2. The charging inlet according to claim 1, wherein the material of the supporting elastic piece or the charging terminal contains a tellurium copper alloy, and the tellurium content in the tellurium copper alloy is 0.1%-5%.

12. 2. The charging inlet according to claim 1, wherein the material of the supporting elastic piece or the charging terminal contains a beryllium copper alloy, and the beryllium content in the beryllium copper alloy is 0.05%-5%.

13. The charging inlet according to claim 1, characterized in that the material of the support elastic piece or the charging terminal contains a phosphorus bronze alloy, and the phosphorus content in the phosphorus bronze alloy is 0.01% to 1.5%.

14. The charging inlet according to claim 1, characterized in that the material of the supporting elastic piece or the charging terminal contains a lead-brass alloy, and the lead content of the lead-brass alloy is 0.1% to 5%.

15. The charging inlet according to claim 1, wherein the cross-sectional area of ​​the inner hole on one side of the insertion hole that is closer to the terminal body is larger than the cross-sectional area of ​​the inner hole on one side that is farther from the terminal body.

16. 2. The charging inlet according to claim 1, wherein the thickness of one side of the opening of the insertion hole of the elastic sheet is greater than or equal to the thickness of one side of the opening of the insertion hole that is closer to the terminal body.

17. 2. The charging inlet according to claim 1, wherein the support elastic piece contacts the elastic sheet and applies a pressure of 0.5N-95N to the elastic sheet.

18. A charging inlet as described in claim 1, characterized in that the maximum outer diameter of the supporting elastic piece in its natural state is greater than or equal to the maximum outer diameter of the inner wall of the cavity.

19. The charging inlet according to claim 18, wherein the supporting elastic piece contacts the inner peripheral wall of the cavity and applies a pressure of 0.5N-100N to the inner peripheral wall of the cavity.

20. 2. The charging inlet according to claim 1, wherein the material of the elastic sheet contains a tellurium copper alloy, and the tellurium content in the tellurium copper alloy is 0.1%-5%.

21. 2. The charging inlet according to claim 1, wherein the material of the elastic sheet contains a beryllium copper alloy, and the beryllium content of the beryllium copper alloy is 0.05%-5%.

22. 2. The charging inlet according to claim 1, wherein the material of the elastic sheet contains a phosphorus bronze alloy, and the phosphorus content of the phosphorus bronze alloy is 0.01% to 1.5%.

23. 2. The charging inlet according to claim 1, wherein the material of the elastic sheet contains a lead-brass alloy, and the lead content of the lead-brass alloy is 0.1% to 5%.

24. 10. A vehicle comprising a charging inlet in which the terminal according to claim 1 is centered with high precision.

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