Evaluation method

Abstract

To provide an evaluation method capable of appropriately evaluating the cooling performance of a connector. [Solution] The evaluation method evaluates the cooling performance of a connector by connecting a pair of reference terminals 100 in a reference jig to a pair of male terminals 11 in a connector that has a pair of male terminals 11 that can be cooled by a coolant. This evaluation method includes a connecting step of connecting a pair of reference terminals 100 to the pair of male terminals 11, and an evaluation step of evaluating the cooling performance by checking whether the temperatures of the male terminals 11 and the reference terminals 100 are 90°C or less when a charging current of 400A is supplied to the male terminals 11 and the reference terminals 100 for 30 minutes in a state where the resistance, including the resistance of the contact points between the male terminals 11 and the reference terminals 100, is 0.06mΩ or more and 0.15mΩ or less.

Description

[Technical field]

[0001] The present disclosure relates to an evaluation method. [Background technology]

[0002] The connection between the equipment-side charging connector and the vehicle-side charging inlet generates heat due to contact resistance when electricity is applied. This is particularly noticeable when rapid charging is performed with a large current (e.g., 400 A). For this reason, liquid-cooled charging connectors that can cool the charging connector with liquid such as water are known. For example, JP 2019-187035 A discloses a liquid-cooled charging connector that includes a connector that can be connected to a vehicle inlet and a cooling mechanism that can cool the connector with a coolant (cooling water). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2019-187035 A Summary of the Invention [Problem to be solved by the invention]

[0004] In a charging connector such as that described in JP 2019-187035 A, variations in cooling performance affect charging time. For example, a charging connector with relatively low cooling performance requires a long charging time. Therefore, there is a need to appropriately evaluate the cooling performance of a charging connector.

[0005] An object of the present disclosure is to provide an evaluation method capable of appropriately evaluating the cooling performance of a connector. [Means for solving the problem]

[0006] In order to solve the above problem, it is conceivable to evaluate the cooling performance of the charging connector (the degree of temperature rise at the connection between the male terminals and the female terminals) using an evaluation jig having a pair of female terminals that can be connected to a pair of male terminals of the charging connector.

[0007] Here, if the contact resistance between the male terminal and the female terminal during the evaluation changes with each evaluation, the reliability of the evaluation results decreases. For this reason, it is desirable to evaluate the cooling performance in a state where the contact resistance is within a predetermined range.

[0008] On the other hand, the contact resistance varies depending on the measurement point of the male terminal and the measurement point of the female terminal. For this reason, it is preferable to appropriately determine the measurement points of each terminal. The present disclosure has been made based on the above viewpoint.

[0009] An evaluation method according to one aspect of the present disclosure is a charging connector including a pair of male terminals that can be cooled by a coolant and a bottom wall that holds the pair of male terminals in a state in which the pair of male terminals are inserted, by connecting the pair of female terminals in an evaluation jig that includes a pair of female terminals connectable to the pair of male terminals, and evaluating the cooling performance of the charging connector, the method including a connection step of connecting the pair of female terminals to the pair of male terminals, and an adjustment step of adjusting a connection state between the male terminals and the female terminals so that contact resistance between the male terminals and the female terminal falls within a predetermined range, and in the adjustment step, the resistance between a point of the male terminal that is 4.5 mm from the surface of the bottom wall and a point of the female terminal that is 43 mm from the surface of the bottom wall is measured as the contact resistance.

[0010] In this evaluation method, the measurement point of the contact resistance between the male terminal and the female terminal is determined, so that it is possible to obtain an appropriate evaluation result of the cooling performance. Specifically, the measurement point on the male terminal side is a point 4.5 mm from the surface of the bottom wall. At this point, the cross-sectional area of ​​the male terminal is sufficiently large, so that the effect on the contact resistance is small. In addition, the measurement point on the female terminal side is a point 43 mm from the surface of the bottom wall. This point is near the boundary between an area affected by the standard and an area not affected by the standard when designing a charging connector including a male terminal. Therefore, by designing the female terminal of the charging inlet so that the contact resistance is equal to or less than the contact resistance measured at this point, the temperature of the male terminal and the female terminal during charging can be suppressed to a standard value or less when charging is performed by a charging connector that satisfies the standard.

[0011] It is preferable that the evaluation method further includes an evaluation step of evaluating the cooling performance based on whether or not the temperatures of the male terminals and the female terminals are 90°C or lower when a charging current of 400 A is supplied to the male terminals and the female terminals for 30 minutes after the adjustment step. Effect of the Invention

[0012] According to the present disclosure, it is possible to provide an evaluation method capable of appropriately evaluating the cooling performance of a connector. [Brief description of the drawings]

[0013] [Figure 1] FIG. 2 is a diagram illustrating a state in which a vehicle is being charged. [Diagram 2] FIG. [Diagram 3] FIG. 3 is a cross-sectional view taken along line III-III in FIG. [Figure 4] FIG. 1 is a perspective view of an evaluation jig according to an embodiment of the present disclosure. [Diagram 5] FIG. 2 is a perspective view of the vicinity of a female terminal of the evaluation jig. [Figure 6] FIG. 4 is a perspective view showing the relationship between a female terminal of the evaluation jig and an adjustment member. [Figure 7] FIG. 4 is a plan view of a female terminal of the evaluation jig. [Figure 8] FIG. 8 is a perspective view of the female terminal shown in FIG. [Figure 9] 9 is a perspective view of the female terminal at a different angle from that in FIG. 8. [Figure 10] FIG. 4 is an enlarged perspective view of a tip portion of the female terminal. [Figure 11] 10 is a cross-sectional view taken along line XI-XI in FIG. [Figure 12] 8 is a cross-sectional view taken along line XII-XII in FIG. 7. [Figure 13] FIG. 13 is an enlarged view of the area indicated by solid line XIII in FIG. [Figure 14] 4 is a front view of the male connector with a portion of the cylindrical wall removed. FIG. [Figure 15] FIG. 15 is a perspective view of the male connector shown in FIG. [Figure 16] 16 is a cross-sectional view taken along line XVI-XVI in FIG. 14. [Figure 17] 16 is a perspective view showing a state in which a female terminal of an evaluation jig is connected to a male terminal of the male connector shown in FIG. 15. [Figure 18] FIG. 18 is a cross-sectional view of the view shown in FIG. [Figure 19] 4 is a diagram showing an outline of the degree of temperature rise at each portion around the connection portion between the male terminal and the female terminal. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present disclosure will now be described with reference to the accompanying drawings, in which the same or corresponding components are designated by the same reference numerals.

[0015] Fig. 1 is a diagram that shows a schematic diagram of a state in which a vehicle is being charged. More specifically, Fig. 1 shows a state in which a charging connector 5 that is connected to equipment 7 such as a charging stand via an equipment-side electric wire 6 is connected to a charging inlet 2 of the vehicle 1. The vehicle 1 is, for example, an electric vehicle.

[0016] The charging connector 5 includes a handle (not shown) that is held by a user, and a male connector 10 (see FIG. 2) that is connected to the handle. The charging connector 5 is cooled by a coolant. In other words, the charging connector 5 is a so-called liquid-cooled charging connector. An example of the coolant is cooling water. The coolant flows between the equipment 7 and the charging connector 5 via the equipment-side electric wires 6.

[0017] The male connector 10 is a portion that is connected to the charging inlet 2 of the vehicle 1. In this embodiment, the male connector 10 is based on the ChaoJi standard. As shown in Fig. 2, the male connector 10 has a pair of male terminals 11, a protective earth terminal 12, a pair of charging connection confirmation terminals 13, a pair of charging communication terminals 14, and a male casing 15.

[0018] Each male terminal 11 is formed in a cylindrical shape. Each male terminal 11 is a DC power supply terminal. One male terminal 11 is a positive electrode, and the other male terminal 11 is a negative electrode. In this embodiment, the outer diameter of the male terminal 11 is 9 mm.

[0019] The protective earth terminal 12 is located at a position spaced from the center between the pair of male terminals 11 to one side in an orthogonal direction (up and down direction in Figure 2) that is perpendicular to both the direction connecting the pair of male terminals 11 (left and right direction in Figure 2) and the axial direction of each male terminal 11.

[0020] Each charging connection confirmation terminal 13 is disposed at a position spaced from one male terminal 11 on one side in the orthogonal direction.

[0021] Each charging communication terminal 14 is arranged at a position spaced apart from the other male terminal 11 on one side in the orthogonal direction, and at a position spaced apart from each charging connection confirmation terminal 13 in a direction parallel to the direction connecting the pair of male terminals 11.

[0022] The male casing 15 holds the terminals 11 to 14. The male casing 15 is made of resin. The male casing 15 has a bottom wall 16 and a cylindrical wall 17.

[0023] As shown in Fig. 3, bottom wall 16 holds each of terminals 11 to 14 while terminals 11 to 14 are inserted therethrough. Bottom wall 16 is formed in a flat plate shape. Note that Fig. 3 shows a portion of female connector 20 of charging inlet 2.

[0024] The cylindrical wall 17 surrounds the male terminal 11. The cylindrical wall 17 stands up from a portion of the bottom wall 16 surrounding the male terminal 11. The cylindrical wall 17 has a cylindrical inner circumferential surface. The female connector 20 of the charging inlet 2 is inserted into the space between this inner circumferential surface and the outer circumferential surface of the male terminal 11. As shown in FIG. 3, the inner diameter of the cylindrical wall 17 is set to 23 mm.

[0025] The charging inlet 2 is provided on the outer surface of the vehicle 1. The charging inlet 2 includes a female connector 20. The female connector 20 has a pair of female terminals 21 and a female casing 25.

[0026] Each female terminal 21 is connectable to a male terminal 11. As shown in FIG.

[0027] The female casing 25 holds the female terminal 21. The female casing 25 is made of resin. As shown in FIG. 3, the female casing 25 has an opposing portion 26 and a cylindrical portion 27.

[0028] The facing portion 26 is a portion facing the cylindrical wall 17 in a direction parallel to the axial direction of the male terminal 11 (the vertical direction in FIG. 3). A surface 26S of the facing portion 26 is formed flat. As shown in FIG. 3, the distance between the surface 26S of the facing portion 26 and the surface 16S of the bottom wall 16 in the direction parallel to the axial direction of the male terminal 11 is set to 40 mm.

[0029] The tubular portion 27 is formed in a cylindrical shape surrounding the female terminal 21. The tubular portion 27 is connected to the opposing portion 26 with the central axis of the tubular portion 27 perpendicular to the opposing portion 26. The outer diameter of the tubular portion 27 is smaller than the inner diameter of the tube wall 17. When the charging connector 5 is connected to the charging inlet 2, the tip portion 27a of the tubular portion 27 abuts against the surface 16S of the bottom wall 16. As shown in FIG. 3, the length of the tip portion 27a in a direction parallel to the axial direction of the tubular portion 27 is set to 6 mm.

[0030] Next, the evaluation jig 50 will be described with reference to Fig. 4 to Fig. 13. The evaluation jig 50 is a jig capable of evaluating the cooling performance (amount of heat generated at the connection between the male terminal 11 and the female terminal) of the charging connector 5. As shown in Fig. 4, the evaluation jig 50 includes a pair of female terminals 100, an electric wire 200, a pair of crimp terminals 300, and a pair of adjustment members 400.

[0031] Each female terminal 100 is a terminal to be connected to a male terminal 11. Each female terminal 100 has a plurality of contact pieces 110 (eight in this embodiment), a support portion 120, and a female side flange .

[0032] Each contact piece 110 is a portion capable of coming into contact with a male terminal 11. The multiple contact pieces 110 are arranged at intervals around the central axis A (see FIGS. 11 to 13). Specifically, the multiple contact pieces 110 are arranged at equal intervals around the central axis A. The number of contact pieces 110 is preferably set to 3 or more and 8 or less, and is particularly preferably set to 8. Each contact piece 110 has a flexible piece 112 and a contact portion 114.

[0033] The flexible pieces 112 have a shape extending in a direction parallel to the central axis A. The flexible pieces 112 form a part of a cylinder having the central axis A. That is, in the cross sections shown in Figures 12 and 13, the outer peripheral surface of the flexible pieces 112 is arc-shaped. A slit 112S is provided between a pair of flexible pieces 112 adjacent to each other in the circumferential direction of the cylinder.

[0034] The length L1 (see FIG. 7) of flexible piece 112 in a direction parallel to central axis A is set to be at least twice the outer diameter of the cylinder. In this embodiment, the outer diameter φ2 (see FIG. 11) of the cylinder is 17 mm, and the length L1 of flexible piece 112 is 35 mm. The inner diameter φ1 (see FIG. 11) of the cylinder is 13 mm. In other words, the thickness of flexible piece 112 is 2 mm.

[0035] The flexible piece 112 is elastically deformable such that a tip end 112a of the flexible piece 112 is displaced in the radial direction of the cylinder with respect to a base end which is a connection portion between the flexible piece 112 and the support portion 120. In other words, the multiple contact pieces 110 (the cylinder) are capable of contracting in diameter.

[0036] 12 and 13, the flexible piece 112 has an opposing surface 112b that faces the adjacent flexible piece 112 in the circumferential direction of the cylinder. The pair of opposing surfaces 112b that face each other in the circumferential direction are parallel to each other. The distance between the pair of opposing surfaces 112b is 1 mm.

[0037] The contact portion 114 has a shape that protrudes from the inner surface of the flexible plate 112 toward the central axis A. The contact portion 114 is connected to a portion of the inner surface of the flexible plate 112 that is spaced apart from the tip portion 112a in a direction parallel to the central axis A. In other words, the tip portion 112a of the flexible plate 112 forms a protrusion that protrudes from the contact portion 114 in a direction that is parallel to the central axis A and away from the support portion 120 (downward in FIG. 11).

[0038] The contact portion 114 has a curved shape that is convex inward in the radial direction. As shown in Fig. 13, the boundary portion 113 between the flexible piece 112 and the contact portion 114 has a curved shape. The curvature of the apex 114c of the contact portion 114 is smaller than the curvature of the boundary portion 113. In this embodiment, the radius of curvature of the apex 114c is 1 mm. The radius of curvature of the boundary portion 113 is, for example, 0.5 mm.

[0039] 13, the angle between a line connecting a specific apex 114c and the central axis A and a line connecting an apex 114c adjacent to the specific apex 114c and the central axis A is set to 45 degrees. The angle between a tangent to one end of the contact portion 114 in the circumferential direction and a tangent to the other end of the contact portion 114 in the circumferential direction is set to 30 degrees.

[0040] The contact portion 114 has a shape extending along a direction parallel to the central axis A. As shown in Figures 10 and 11, the contact portion 114 has a contact edge portion 114a and a connecting portion 114b.

[0041] The contact edge portion 114a has a shape extending along a direction parallel to the central axis A. The length L3 of the contact edge portion 114a is set to 4.7 mm.

[0042] The connecting portion 114b connects the contact edge portion 114a and the inner surface of the flexible plate 112. The connecting portion 114b has a shape that is inclined so as to gradually approach the inner surface of the flexible plate 112 as it moves away from the contact edge portion 114a in a direction parallel to the central axis A. The radius of curvature of the boundary between the connecting portion 114b and the inner surface of the flexible plate 112 is 0.5 mm. The radius of curvature of the boundary between the connecting portion 114b and the contact edge portion 114a is 1.5 mm.

[0043] The support portion 120 supports the multiple contact pieces 110. In this embodiment, the support portion 120 is formed in a cylindrical shape centered on the central axis A. The outer circumferential surface of the support portion 120 is continuously connected to the outer circumferential surfaces of the flexible pieces 112. In other words, the outer diameter of the support portion 120 is the same as the outer diameter of the cylinder formed by the multiple flexible pieces 112.

[0044] As shown in Fig. 11, the thickness of the support portion 120 is the same as the thickness of each flexible piece 112. As shown in Fig. 7, the length L2 of the support portion 120 in the direction of the central axis A is set to be smaller than the length L1 of each flexible piece 112. Specifically, the length L2 of the support portion 120 is 22 mm. The support portion 120 may be formed in a cylindrical shape, a square tube shape, or the like.

[0045] The female flange 130 has a shape that protrudes outward in the radial direction of the support part 120 from the outer circumferential surface of the support part 120. The female flange 130 is formed flat. The length of the female flange 130 in the direction parallel to the central axis A is set to be the same as that of the support part 120 (22 mm in this embodiment).

[0046] An insertion hole 130h is provided in the female flange 130. The diameter of the insertion hole 130h is 10.5 mm. The distance between the central axis A and the center of the insertion hole 130h is 21 mm.

[0047] The electric wire 200 is for connecting a pair of female terminals 100 to each other. The electric wire 200 is made of copper or silver. The cross-sectional area of ​​the electric wire 200 is 70 mm 2 Over 95mm 2 In this embodiment, the cross-sectional area of ​​the wire 200 is preferably set to 95 mm 2 The length of the electric wire 200 is set to 2 m or more. The reason for this will be explained with reference to FIG.

[0048] Fig. 19 shows the temperatures of each terminal and each electric wire when a current of 400 A is supplied for 30 minutes with male terminal 11 connected to female terminal 21. In Fig. 19, region R of the connection between male terminal 11 and female terminal 21 is the region with the highest temperature.

[0049] As shown in FIG. 19, the cross-sectional area of ​​the vehicle-side electric wire 3 is 95 mm 2 In this case, it was confirmed that the temperature of the portion of the vehicle-side electric wire 3 100 cm away from the female terminal 21 is stable (the effect of heat generation at the connection between the male terminal 11 and the female terminal 21 becomes substantially negligible), both when the portion 100 cm from the male terminal 11 is water-cooled and when said portion is not water-cooled.

[0050] In addition, when the above-mentioned portion is water-cooled, the cross-sectional area of ​​the vehicle-side electric wire 3 is 70 mm 2 and 95mm2 In either case, it was confirmed that the temperature of the portion of the vehicle-side electric wire 3 100 cm away from the female terminal 21 was stable (the effect of heat generation at the connection between the male terminal 11 and the female terminal 21 was essentially negligible).

[0051] From the above results, it is found that by making the length of the electric wire 200 2 m or more, the influence of heat generated at the connection portion between one male terminal 11 and one female terminal 21 on the connection portion between the other male terminal 11 and the other female terminal 21 through the electric wire can be neglected. Therefore, in this embodiment, the length of the electric wire 200 is set to 2 m or more.

[0052] Each crimp terminal 300 is connected to an end 210 of an electric wire 200. Each crimp terminal 300 has a crimp portion 310 and a crimp side flange 320.

[0053] The crimping portion 310 crimps the end 210 of the electric wire 200 .

[0054] The crimping side flange 320 is connected to the crimping portion 310. The crimping side flange 320 is formed flat. An insertion hole (not shown) is provided in the crimping side flange 320. The crimping side flange 320 is fixed to the female side flange 130 by a bolt B and a nut (not shown). The bolt B is inserted through the insertion hole 130h of the female side flange 130 and the insertion hole of the crimping side flange 320.

[0055] The adjustment member 400 is capable of adjusting the contact resistance between the female terminals 100 and the male terminals 11. Specifically, the adjustment member 400 is capable of applying an external force to each female terminal 100 to reduce the diameter of the female terminal 100. The adjustment member 400 has an annular band 410, a metal band 420, and an adjustment portion 430.

[0056] The annular band 410 is attached around the multiple contact pieces 110. The annular band 410 surrounds the entire circumference of the multiple contact pieces 110. The annular band 410 is made of a material (such as resin) having electrical insulation and thermal insulation properties. The length of the annular band 410 in a direction parallel to the central axis A is smaller than the length of the slit 112S in the same direction.

[0057] Metal band 420 is wound around annular band 410. Metal band 420 is capable of applying an external force to a plurality of contact pieces 110 of female terminal 100 to cause the diameter of the plurality of contact pieces 110 to decrease.

[0058] The adjustment unit 430 can adjust the fastening force of the metal band 420 on the multiple contact pieces 110 (external force that reduces the diameter of the multiple contact pieces 110). Specifically, the adjustment unit 430 adjusts the fastening force by adjusting the diameter of the metal band 420. The adjustment unit 430 has a screw that can adjust the diameter of the metal band 420.

[0059] Next, a method for evaluating the cooling performance of the charging connector 5 using the evaluation jig 50 will be described. Specifically, the cooling performance of the charging connector 5 is evaluated by connecting a pair of female terminals 100 of the evaluation jig 50 to a pair of male terminals 11 of the male connector 10. This evaluation method includes a removing step, a connecting step, an adjusting step, and an evaluating step.

[0060] The removing step is a step of removing a part of each cylindrical wall 17 of the male casing 15. Specifically, as shown in Figs. 13 to 15, in the removing step, a part of each cylindrical wall 17 is removed so that an operation space 17S is formed around the male terminal 11, which allows the adjustment of the external force by the adjustment unit 430. As a result, a part of each male terminal 11 is exposed. Therefore, in the removing step, a portion capable of suppressing a short circuit between the male terminals 11 or between the male terminals 11 and the other terminals 12 to 14, that is, a portion of the cylindrical wall 17 other than the portion where the pair of cylindrical walls 17 face each other, is removed. In this embodiment, a portion of the cylindrical wall 17 outside the male terminal 11 in the direction connecting the male terminal 11 and the protective earth terminal 12 is removed.

[0061] The connecting step is a step of connecting a pair of female terminals 100 of the evaluation jig 50 to a pair of male terminals 11. In the connecting step, the female terminals 100 are connected to the male terminals 11 in a state in which the annular bands 410 and the metal bands 420 are attached around the contact pieces 110 of each female terminal 100. As shown in Fig. 17 and Fig. 18, in the connecting step, the female terminals 100 are inserted until the tip portions 112a of the flexible pieces 112 abut against the surface 16S of the bottom wall 16 of the male casing 15. Note that Fig. 17 shows a state in which only one female terminal 100 is inserted into the male terminal 11.

[0062] The adjustment process is a process for adjusting the connection state between the male terminal 11 and the female terminal 100. Specifically, in the adjustment process, the external force (the fastening force by the metal band 420) is adjusted by the adjustment unit 430. More specifically, in the adjustment process, the external force is adjusted by operating the adjustment unit 430 with an operation tool (not shown) in the operation space 17S so that the contact resistance between the male terminal 11 and the female terminal 100 falls within a predetermined range. In this process, for example, the fastening force of the adjustment unit 430 is adjusted by the operation tool from above in FIG. 17.

[0063] In the adjusting step, the external force is preferably adjusted so that the contact resistance is 0.06 mΩ or more and 0.15 mΩ or less, and more preferably, the external force is adjusted so that the contact resistance is 0.08 mΩ or more and 0.1 mΩ or less.

[0064] Here, the contact resistance is measured as a resistance value between point P1, which is 4.5 mm from surface 16S of bottom wall 16, and point P2, which is 43 mm from surface 16S of bottom wall 16, as shown in Fig. 18. This contact resistance may be measured by a milliohm tester, or may be obtained from a voltage drop when a current of 400 A is supplied. Point P2 is located near the boundary between an area that is affected by standards and an area that is not affected by standards when designing male connector 10 including male terminal 11.

[0065] In the evaluation process, the cooling performance is evaluated based on whether the temperatures of the male terminal 11 and the female terminal 100 are 90° C. or less when a charging current of 400 A is supplied for 30 minutes with the male terminal 11 and the female terminal 100 connected. The temperatures of the male terminal 11 and the female terminal 100 may be detected by a temperature sensor (not shown) provided on the male terminal 11 or the female terminal 100.

[0066] As described above, by using the evaluation jig 50 of this embodiment, it is possible to appropriately evaluate the amount of heat generated by the charging connector 5 when electricity is applied.

[0067] The exemplary embodiments described above are examples of the following aspects.

[0068] The evaluation jig of the above embodiment includes a pair of female terminals connectable to a pair of male terminals of a charging connector, and an electric wire connecting the pair of female terminals, the cross-sectional area of ​​the electric wire being 70 mm 2 Over 95mm 2 and the length of the electric wire is 2 m or more.

[0069] In this evaluation jig, the cross-sectional area of ​​the wire is 70 mm 2 Over 95mm 2 Since the length of the electric wire is 2m or more, it is possible to appropriately evaluate the amount of heat generated (degree of temperature rise) at the connection between the male terminal and the female terminal when electricity is passed through (when evaluating), without being substantially affected by the heat dissipation characteristics of the electric wire. This makes it possible to design each terminal based on the evaluation results.

[0070] The electric wire is preferably made of copper.

[0071] The evaluation jig also includes a pair of female terminals connectable to a pair of male terminals of a charging connector, and an adjustment member capable of adjusting the contact resistance between the female terminals and the male terminal, wherein the female terminals are contractible in diameter, and the adjustment member is attached to the outer peripheral surface of the female terminal and has an annular band formed in a ring shape surrounding the female terminal, a metal band attached to the outer peripheral surface of the annular band and capable of applying an external force to the female terminal to contract the female terminal in diameter, and an adjustment portion capable of adjusting the external force applied to the female terminal by the metal band, and the annular band is made of a material having electrical and thermal insulation properties.

[0072] This evaluation jig is equipped with an adjustment unit that can adjust the external force (clamping force) applied to the female terminal by the metal band, so that the contact resistance between the male terminal and the female terminal can be adjusted, and furthermore, the annular band disposed between the female terminal and the metal band is made of a material having electrical and thermal insulation properties, so that heat dissipation in the metal band or the adjustment unit is suppressed, thereby suppressing a decrease in the evaluation accuracy of the amount of heat generated at the connection between the male terminal and the female terminal.

[0073] Moreover, the evaluation method of the above embodiment is a method for evaluating the cooling performance of a charging connector by connecting a pair of female terminals in an evaluation jig having a pair of female terminals connectable to a pair of male terminals in a charging connector that has a pair of male terminals that can be cooled by a coolant, and includes a connection step of connecting the pair of female terminals to the pair of male terminals, an adjustment step of adjusting the connection state between the male terminals and the female terminals so that the contact resistance between the male terminals and the female terminals is 0.06 mΩ or more and 0.15 mΩ or less, and an evaluation step of evaluating the cooling performance based on whether or not the temperatures of the male terminals and the female terminals are 90°C or less when a charging current of 400 A is supplied to the male terminals and the female terminals for 30 minutes after the adjustment step.

[0074] In this evaluation method, the contact resistance between the male terminal and the female terminal is specified to be in the range of 0.06 mΩ to 0.15 mΩ, which suppresses variation in the evaluation results. This makes it possible to appropriately evaluate the cooling performance of the charging connector. Furthermore, by designing the female terminal of the charging inlet so that the contact resistance is in the range of 0.06 mΩ to 0.15 mΩ, when charging is performed using a charging connector that has obtained good evaluation results in the evaluation process, the temperature of the male terminal and female terminal will be 90°C or lower when a charging current of 400 A is supplied for 30 minutes.

[0075] In the adjusting step, the connection state is preferably adjusted so that the contact resistance is not less than 0.08 mΩ and not more than 0.1 mΩ.

[0076] Furthermore, the evaluation method of the above embodiment is an evaluation method for evaluating cooling performance of a charging connector, the charging connector including a pair of male terminals that can be cooled by a coolant and a bottom wall that holds the pair of male terminals in a state in which the pair of male terminals are inserted, by connecting the pair of female terminals in an evaluation jig that includes a pair of female terminals that can be connected to the pair of male terminals, the evaluation method including a connection step of connecting the pair of female terminals to the pair of male terminals, and an adjustment step of adjusting a connection state between the male terminals and the female terminals so that the contact resistance between the male terminals and the female terminal falls within a predetermined range, and in the adjustment step, the resistance between a point of the male terminal that is 4.5 mm from the surface of the bottom wall and a point of the female terminal that is 43 mm from the surface of the bottom wall is measured as the contact resistance.

[0077] In this evaluation method, the measurement point of the contact resistance between the male terminal and the female terminal is determined, so that it is possible to obtain an appropriate evaluation result of the cooling performance. Specifically, the measurement point on the male terminal side is a point 4.5 mm from the surface of the bottom wall. At this point, the cross-sectional area of ​​the male terminal is sufficiently large, so that the effect on the contact resistance is small. In addition, the measurement point on the female terminal side is a point 43 mm from the surface of the bottom wall. This point is near the boundary between an area affected by the standard and an area not affected by the standard when designing a charging connector including a male terminal. Therefore, by designing the female terminal of the charging inlet so that the contact resistance is equal to or less than the contact resistance measured at this point, the temperature of the male terminal and the female terminal during charging can be suppressed to a standard value or less when charging is performed by a charging connector that satisfies the standard.

[0078] It is preferable that the evaluation method further includes an evaluation step of evaluating the cooling performance based on whether or not the temperatures of the male terminals and the female terminals are 90°C or lower when a charging current of 400 A is supplied to the male terminals and the female terminals for 30 minutes after the adjustment step.

[0079] In addition, the evaluation jig of the above embodiment includes a pair of female terminals that can be connected to a pair of male terminals of a charging connector, and an adjustment member that can adjust the contact resistance between the female terminals and the male terminal, wherein the female terminals are capable of being contracted in diameter, and the adjustment member is capable of applying an external force to the female terminals that contracts the female terminals in diameter.

[0080] In this evaluation jig, the female terminal can be contracted, and the adjustment member can apply an external force to the female terminal to contract the female terminal, so that the contact resistance between the male terminal and the female terminal can be adjusted to be within a predetermined range, thereby making it possible to appropriately evaluate the cooling performance of the charging connector.

[0081] Moreover, the evaluation method of the above embodiment is an evaluation method for evaluating cooling performance of a charging connector by connecting a pair of female terminals in an evaluation jig that includes a pair of male terminals that can be cooled by a coolant and a pair of cylindrical walls surrounding each of the male terminals of the pair of male terminals to the pair of male terminals, the evaluation method including a pair of female terminals that can be connected to the pair of male terminals and can be reduced in diameter, and an adjustment member that can apply an external force to each of the pair of female terminals to reduce the diameter of the female terminals of the pair of female terminals, the evaluation method including the steps of: removing a portion of each of the pair of cylindrical walls so that an operation space is formed around the male terminals in which the external force can be adjusted by the adjustment member; connecting the pair of female terminals to the pair of male terminals; and adjusting the external force by the adjustment member in the operation space so that contact resistance between the male terminals and the female terminals is within a predetermined range.

[0082] In this evaluation method, an operational space is formed around the male terminal which allows for adjustment of the external force, making it possible to adjust the contact resistance while the female terminal of the evaluation jig is connected to the male terminal.

[0083] In the removing step, it is preferable to remove a portion of the cylindrical wall other than the portion where the pair of cylindrical walls face each other.

[0084] In this way, short circuits between the male terminals are prevented.

[0085] The adjustment member may have an annular band attached to the outer peripheral surface of the female terminal and formed in a ring shape surrounding the female terminal, a metal band attached to the outer peripheral surface of the annular band and capable of applying a force to the female terminal to reduce the diameter of the female terminal, and an adjustment portion capable of adjusting the fastening force of the female terminal by the metal band, and the annular band may be made of a material having electrical insulation and thermal insulation properties. In this case, it is preferable that in the connecting step, the pair of female terminals are connected to the pair of male terminals with the annular band and the metal band attached to each of the female terminals, and in the adjusting step, the fastening force of the female terminal by the metal band is adjusted in the operation space.

[0086] In addition, the evaluation jig of the above embodiment has a female terminal that can be connected to a male terminal of a charging connector, and the female terminal has a plurality of contact pieces that are each capable of contacting the male terminal and are arranged at intervals around a central axis, and a support portion that supports the plurality of contact pieces, and each of the plurality of contact pieces has a flexible piece having a shape extending from the support portion along a direction parallel to the central axis, and a contact portion that protrudes from the inner surface of the flexible piece toward the central axis, and the flexible piece forms part of a cylinder having the central axis, and the length of the flexible piece in the direction parallel to the central axis is more than twice the outer diameter of the cylinder, and the flexible piece is elastically deformable so that a tip end of the flexible piece is displaced in the radial direction of the cylinder relative to a base end that is a connection between the flexible piece and the support portion, and the contact portion has a shape that is curved so as to be convex inward in the radial direction.

[0087] In this evaluation jig, the length of the flexible pieces in the direction parallel to the central axis is more than twice the outer diameter of the cylinder, so that plastic deformation of each flexible piece is suppressed when the female terminal is repeatedly connected to and removed from the male terminal, and each contact part has a shape that is curved so as to be convex inward in the radial direction, so that it stably contacts the male terminal. Therefore, a predetermined contact resistance can be stably reproduced, making it possible to appropriately evaluate the cooling performance of the charging connector.

[0088] It is also preferable that the contact portion has a shape extending in a direction parallel to the central axis.

[0089] In this way, even if the female terminal is connected to the male terminal with its central axis inclined relative to the central axis of the male terminal, the orientation of the female terminal is induced so that both central axes are aligned.

[0090] It is also preferable that the flexible piece has a protrusion that protrudes from the contact portion in a direction parallel to the central axis and away from the support portion.

[0091] It is also preferable that the boundary between the flexible plate and the contact portion has a curved shape.

[0092] In this case, it is preferable that the curvature of the apex of the contact portion is smaller than the curvature of the boundary portion.

[0093] It is also preferable that the flexible piece has an opposing surface that faces an adjacent flexible piece in the circumferential direction of the cylinder, and that the pair of opposing surfaces that face each other in the circumferential direction are parallel to each other.

[0094] It should be noted that the embodiments disclosed herein are illustrative in all respects and should not be considered as limiting. The scope of the present invention is indicated by the claims, not by the description of the embodiments above, and further includes all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0095] 1 vehicle, 2 charging inlet, 3 vehicle side electric wire, 5 charging connector, 6 equipment side electric wire, 7 equipment, 10 male connector, 11 male terminal, 15 male casing, 16 bottom wall, 17 tube wall, 17S operation space, 20 female connector, 21 female terminal, 25 female casing, 26 opposing portion, 27 tube portion, 27a tip portion, 50 evaluation jig, 100 female terminal, 110 contact piece, 112 flexible piece, 112a protrusion, 112b opposing surface, 112S slit, 113 boundary portion, 114 contact portion, 114a contact edge portion, 114b connecting portion, 114c top portion, 120 support portion, 130 female side flange, 130h insertion hole, 200 electric wire, 210 end portion, 300 Crimp terminal, 310 crimping portion, 320 crimping side flange, 400 adjustment member, 410 annular band, 420 metal band, 430 adjustment portion, A central axis.

Claims

[Claim 1] A method for evaluating a performance of a connector with respect to a rise in temperature, comprising: connecting a pair of male terminals of a connector that can be cooled by a coolant to a pair of terminals of a jig that has a pair of terminals connectable to the pair of male terminals, the method comprising: a connecting step of connecting the pair of terminals to the pair of male terminals; and an evaluation process for evaluating the performance based on the degree of temperature rise of the male terminal and the terminal when a charging current of 400 A is supplied to the male terminal and the terminal for 30 minutes in a state in which the resistance between the measurement portion of the male terminal and the measurement portion of the terminal, including the resistance of the contact portion between the male terminal and the terminal, is 0.08 mΩ or more and 0.15 mΩ or less.

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