Evaluation fixture

Abstract

The present application discloses an evaluation jig, which is provided with an evaluation terminal capable of being connected to a male terminal of a connector, the evaluation terminal having: a plurality of pieces each having a circular arc surface with respect to a center axis and being arranged at intervals; and a protrusion protruding from an inner surface of each of the pieces, an outer surface of the piece being the circular arc surface, a length of the piece in a direction parallel to the center axis being 4 times or more a radius of curvature of the circular arc surface, the protrusion having a shape bent inward in a radial direction of the circular arc surface, the protrusion having: an inner edge portion having a shape extending in a direction parallel to the center axis; and a connecting portion connecting the inner edge portion and the inner surface of the piece, the connecting portion having a shape inclined so as to gradually approach the inner surface of the piece away from the inner edge portion in the direction parallel to the center axis.

Description

[0001] Divisional Application Instructions

[0002] This application is a divisional application of Chinese invention patent application filed on January 8, 2021, entitled "Evaluation Fixture", with application number 202110026443.8. Technical Field

[0003] This invention relates to evaluation fixtures. Background Technology

[0004] The connection between the charging connector on the device side and the charging port on the vehicle side heats up due to contact resistance when energized. This is particularly noticeable during fast charging with a high current (e.g., 400A). Therefore, liquid-cooled charging connectors capable of being cooled by liquids such as water are known. For example, Japanese Patent Application Publication No. 2019-187035 discloses a liquid-cooled charging connector that includes a connector capable of connecting to a vehicle port and a cooling mechanism capable of cooling the connector with a coolant (cooling water). Summary of the Invention

[0005] In the charging connector disclosed in Japanese Patent Application Publication No. 2019-187035, deviations in cooling performance affect charging time. For example, in a charging connector with poor cooling performance, the charging time becomes longer. Therefore, there is a need to properly evaluate the cooling performance of the charging connector.

[0006] The purpose of this invention is to provide an evaluation fixture that can properly evaluate the cooling performance of a charging connector.

[0007] To address the aforementioned issues, it is proposed to evaluate the cooling performance (the degree of temperature rise at the connection between the male and female terminals) of a charging connector by using an evaluation fixture that can connect to a pair of male terminals of the charging connector.

[0008] If the contact resistance between the male and female terminals changes with each evaluation, the reliability of the evaluation results decreases. Therefore, in evaluating cooling performance, it is desirable to stably reproduce the specified contact resistance.

[0009] According to one aspect of the invention, an evaluation fixture includes an evaluation terminal capable of being connected to a male terminal of a connector. The evaluation terminal comprises: a plurality of plates, each spaced apart around a central axis; and a protrusion protruding from the inner surface of each of the plurality of plates, the outer surface of which is an arcuate surface centered on the central axis. The length of the plate in a direction parallel to the central axis is at least four times the radius of curvature of the arcuate surface. The protrusion has a shape that curves radially inward along the arcuate surface. The protrusion has: an inner edge portion having a shape extending in a direction parallel to the central axis; and a connecting portion connecting the inner edge portion to the inner surface of the plate, the connecting portion having a shape that is inclined in a direction parallel to the central axis, gradually approaching the inner surface of the plate as it moves away from the inner edge portion.

[0010] Furthermore, it is preferable that the radius of curvature of the boundary between the inner edge and the connecting portion is greater than the radius of curvature of the boundary between the connecting portion and the inner surface of the sheet.

[0011] Furthermore, it is preferable that the radius of curvature of the boundary between the connecting portion and the inner surface of the sheet is 0.5 mm.

[0012] Furthermore, the evaluation terminal preferably also has a cylindrical portion, which is connected to the plurality of plates to form a cylindrical shape centered on the central axis.

[0013] Furthermore, the evaluation terminal preferably also has a flange connected to the cylindrical portion, the flange having a shape that extends outward from the outer peripheral surface of the cylindrical portion in a direction orthogonal to the central axis.

[0014] Furthermore, it is preferable that the length of the flange in the direction parallel to the central axis is the same as the length of the cylindrical portion in the direction parallel to the central axis.

[0015] In addition, the flange is preferably provided with an insertion hole.

[0016] The above and other objects, features, aspects and advantages of the invention will become more apparent from the following detailed description of the invention, taken in conjunction with the accompanying drawings. Attached Figure Description

[0017] Figure 1 This is a schematic diagram showing the state of a vehicle being charged.

[0018] Figure 2 This is a front view of the male connector.

[0019] Figure 3 yes Figure 2 The cross-sectional view at line III-III.

[0020] Figure 4 This is a perspective view of an evaluation fixture according to one embodiment of the present invention.

[0021] Figure 5 This is a three-dimensional view of the vicinity of the female terminal of the evaluation fixture.

[0022] Figure 6 This is a perspective view showing the relationship between the female terminal of the evaluation fixture and the adjustment component.

[0023] Figure 7 This is a top view of the female terminal of the evaluation fixture.

[0024] Figure 8 yes Figure 7 A three-dimensional view of the female terminal shown.

[0025] Figure 9 Is with Figure 8 3D view of the female terminals at different angles.

[0026] Figure 10 This is an enlarged 3D view of the front end of the female terminal.

[0027] Figure 11 yes Figure 7 A cross-sectional view at line XI-XI.

[0028] Figure 12 yes Figure 7 A cross-sectional view at line XII-XII in the diagram.

[0029] Figure 13 yes Figure 12 An enlarged view of the area represented by the solid line XIII shown.

[0030] Figure 14 This is a front view of the state after a portion of the cylindrical wall in the male connector has been removed.

[0031] Figure 15 yes Figure 14 A three-dimensional view of the male connector shown.

[0032] Figure 16 yes Figure 14 A cross-sectional view at the XVI-XVI line.

[0033] Figure 17 It is shown Figure 15 The diagram shows a perspective view of the male connector's male terminal being connected to the female terminal of the evaluation fixture.

[0034] Figure 18 yes Figure 17 The figure shown is a cross-sectional view.

[0035] Figure 19It is a diagram that schematically shows the degree of temperature rise in various parts centered on the connection between the male and female terminals. Detailed Implementation

[0036] Embodiments of the present invention will be described with reference to the accompanying drawings. In the drawings referred to below, the same or corresponding components are labeled with the same reference numerals.

[0037] Figure 1 This is a schematic diagram illustrating the charging process of a vehicle. In more detail... Figure 1 The diagram shows the state where the charging port 2 of vehicle 1 is connected to the charging connector 5, which is connected to equipment 7 such as a charging station via the device-side wire 6. Furthermore, vehicle 1 is, for example, an electric vehicle.

[0038] The charging connector 5 includes a handle portion (not shown) for the user to hold and a male connector 10 (see reference) that connects to the handle portion. Figure 2 The charging connector 5 is cooled by a coolant. In other words, the charging connector 5 is a so-called liquid-cooled charging connector. Examples of coolants include cooling water. Furthermore, the coolant flows between the device 7 and the charging connector 5 via the device-side wire 6.

[0039] The male connector 10 is the part that connects to the charging port 2 of the vehicle 1. In this embodiment, the male connector 10 is based on the ChaoJi standard. Figure 2 As shown, the male connector 10 has a pair of male terminals 11, a protective ground terminal 12, a pair of charging connection confirmation terminals 13, a pair of charging communication terminals 14, and a male connector sleeve 15.

[0040] 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 the positive terminal, and the other male terminal 11 is the negative terminal. In this embodiment, the outer diameter of the male terminal 11 is 9 mm.

[0041] The protective grounding terminal 12 is configured to be located from the center between a pair of male terminals 11 toward the direction that connects the pair of male terminals 11. Figure 2 The left and right directions and the axial directions of each male terminal 11 are all orthogonal to each other. Figure 2 The position away from the side (up and down direction) in the middle.

[0042] Each charging connection confirmation terminal 13 is positioned away from a male terminal 11 on one side of the orthogonal direction.

[0043] Each charging communication terminal 14 is configured to be located at a position away from the other male terminal 11 toward the orthogonal direction, and at a position away from each charging connection confirmation terminal 13 in a direction parallel to the direction that connects the pair of male terminals 11.

[0044] The male connector sleeve 15 holds each of the terminals 11 to 14. The male connector sleeve 15 is made of resin. The male connector sleeve 15 has a bottom wall 16 and a cylindrical wall 17.

[0045] like Figure 3 As shown, the bottom wall 16 holds each of the terminals 11-14 in place while they are inserted through it. The bottom wall 16 is formed in a flat plate shape. Furthermore, Figure 3 A portion of the female connector 20 of the charging port 2 is shown.

[0046] A cylindrical wall 17 surrounds the male terminal 11. The cylindrical wall 17 stands upright from the portion of the bottom wall 16 surrounding the male terminal 11. The cylindrical wall 17 has a cylindrical inner circumferential surface. A female connector 20 for a charging socket 2 is inserted into the space between this inner circumferential surface and the outer circumferential surface of the male terminal 11. Figure 3 As shown, the inner diameter of the cylinder wall 17 is set to 23mm.

[0047] Charging port 2 is located on the outer surface of vehicle 1. Charging port 2 includes a female connector 20. The female connector 20 has a pair of female terminals 21 and a female connector sleeve 25.

[0048] Each female terminal 21 can be connected to the male terminal 11. For example... Figure 3 As shown, each female terminal 21 has a shape that can accommodate the male terminal 11.

[0049] The female connector sleeve 25 retains the female terminal 21. The female connector sleeve 25 is made of resin. Figure 3 As shown, the female connector sleeve 25 has an opposing portion 26 and a cylindrical portion 27.

[0050] The opposing portion 26 is in a direction parallel to the axial direction of the male terminal 11. Figure 3 The portion (vertical direction) directly opposite the cylinder wall 17. The surface 26S of the opposing portion 26 is formed flat. For example... Figure 3 As shown, the distance between the surface 26S of the opposing portion 26 and the surface 16S of the bottom wall 16 in a direction parallel to the axial direction of the male terminal 11 is set to 40 mm.

[0051] The cylindrical portion 27 is formed in a cylindrical shape surrounding the female terminal 21. The cylindrical portion 27 is connected to the opposing portion 26 with its central axis orthogonal to the opposing portion 26. The outer diameter of the cylindrical portion 27 is smaller than the inner diameter of the cylindrical wall 17. When the charging connector 5 is connected to the charging socket 2, the front end portion 27a of the cylindrical portion 27 abuts against the surface 16S of the bottom wall 16. Figure 3 As shown, the length of the front end portion 27a in the direction parallel to the axial direction of the cylindrical portion 27 is set to 6 mm.

[0052] Next, refer to Figures 4 to 13The evaluation fixture 50 is described below. The evaluation fixture 50 is a fixture capable of evaluating the cooling performance (heat generation at the connection between the male terminal 11 and the female terminal) of the charging connector 5. For example... Figure 4 As shown, the evaluation fixture 50 includes a pair of female terminals 100, a wire 200, a pair of crimp terminals 300, and a pair of adjustment members 400.

[0053] Each female terminal 100 is a terminal connected to the male terminal 11. Each female terminal 100 has multiple (eight in this embodiment) contact pieces 110, support portions 120, and female side flanges 130.

[0054] Each contact piece 110 is a portion that can contact the male terminal 11. Multiple contact pieces 110 are arranged around a central axis A (see reference). Figures 11-13 The contacts 110 are arranged at intervals. Specifically, multiple contacts 110 are arranged at equal intervals around the central axis A. Furthermore, the number of contacts 110 is preferably set to 3 or more and 8 or less, and particularly preferably 8. Each contact 110 has a flexible piece 112 and a contact portion 114.

[0055] The flexible sheet 112 has a shape extending in a direction parallel to the central axis A. The flexible sheet 112 constitutes part of a cylinder having the central axis A. That is, in Figure 12 as well as Figure 13 In the cross-section shown, the outer circumferential surface of the flexible sheet 112 is arc-shaped. A slit 112S is provided between a pair of adjacent flexible sheets 112 in the circumferential direction of the cylinder.

[0056] The length L1 of the flexible sheet 112 in the direction parallel to the central axis A (refer to...) Figure 7 The outer diameter φ2 of the cylinder is set to be more than twice the outer diameter of the cylinder. In this embodiment, the outer diameter φ2 of the cylinder (refer to...) Figure 11 The diameter of the cylinder is 17mm, and the length L1 of the flexible sheet 112 is 35mm. The inner diameter φ1 of the cylinder (refer to...) Figure 11 The thickness is 13mm. That is to say, the thickness of the flexible sheet 112 is 2mm.

[0057] The flexible sheet 112 can undergo elastic deformation so that the front end portion 112a of the flexible sheet 112 is displaced radially in the cylinder relative to the connection portion between the flexible sheet 112 and the support portion 120, i.e., the base end portion. That is, the plurality of contact pieces 110 (the cylinder) can be reduced in diameter.

[0058] like Figure 12 as well as Figure 13As shown, the flexible sheet 112 has a facing surface 112b that is opposite to the flexible sheet 112 adjacent to it in the circumferential direction of the cylinder. The set of facing surfaces 112b that are opposite to each other in the circumferential direction are parallel to each other. The interval between the set of facing surfaces 112b is 1 mm.

[0059] The contact portion 114 has a shape that protrudes from the inner surface of the flexible sheet 112 toward the central axis A. The contact portion 114 is connected to a portion of the inner surface of the flexible sheet 112 that is away from the front end portion 112a in a direction parallel to the central axis A. That is, the front end portion 112a of the flexible sheet 112 is configured as a protrusion that protrudes away from the support portion 120 in a direction parallel to the central axis A. Figure 11 The downward orientation of the part protrudes from the contact portion 114.

[0060] The contact portion 114 has a shape that curves inwardly along the radial direction. For example... Figure 13 As shown, the boundary portion 113 between the flexible sheet 112 and the contact portion 114 has a curved shape. The curvature of the top 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 top 114c is 1 mm. The radius of curvature of the boundary portion 113 is, for example, 0.5 mm.

[0061] like Figure 13 As shown, the angle between the straight line connecting the specific top 114c and the central axis A and the straight line connecting the adjacent top 114c and the central axis A is set to 45 degrees. The angle between the tangent at one end of the contact portion 114 in the circumferential direction and the tangent at the other end of the contact portion 114 in the circumferential direction is set to 30 degrees.

[0062] The contact portion 114 has a shape that extends in a direction parallel to the central axis A. For example... Figure 10 and Figure 11 As shown, the contact portion 114 has a contact edge portion 114a and a connecting portion 114b.

[0063] The contact edge portion 114a has a shape that extends in a direction parallel to the central axis A. The length L3 of the contact edge portion 114a is set to 4.7 mm.

[0064] The connecting portion 114b connects the contact edge portion 114a to the inner surface of the flexible sheet 112. The connecting portion 114b has an inclined shape that gradually approaches the inner surface of the flexible sheet 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 sheet 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.

[0065] The support portion 120 supports a plurality of contact pieces 110. In this embodiment, the support portion 120 is formed as a cylinder centered on the central axis A. The outer peripheral surface of the support portion 120 is continuous with the outer peripheral surface of each flexible piece 112. That is, the outer diameter of the support portion 120 is the same as the outer diameter of the cylinder composed of the plurality of flexible pieces 112.

[0066] like Figure 11 As shown, the thickness of the support portion 120 is the same as the thickness of each flexible sheet 112. Figure 7 As shown, 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. In addition, the support portion 120 may also be formed in a cylindrical or square tube shape, etc.

[0067] The female flange 130 has a shape that extends radially outward from the outer peripheral surface of the support portion 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 portion 120 (22 mm in this embodiment).

[0068] The female flange 130 is provided with an insertion hole 130h. The diameter of the insertion hole 130h is 10.5mm. The distance between the center shaft A and the center of the insertion hole 130h is 21mm.

[0069] Wire 200 is used to connect a pair of female terminals 100 to each other. Wire 200 is made of copper or silver. The cross-sectional area of ​​wire 200 is preferably set to 70 mm² or more and 95 mm² or less. In this embodiment, the cross-sectional area of ​​wire 200 is set to 95 mm². The length of wire 200 is set to 2 m or more. (Refer to...) Figure 19 To explain this reasoning.

[0070] Figure 19 The temperature of each terminal and each wire is shown when a current of 400A is supplied for 30 minutes with male terminal 11 and female terminal 21 connected. Additionally, in... Figure 19 In the middle, the area R of the connection between the male terminal 11 and the female terminal 21 is the area with the highest temperature.

[0071] like Figure 19 As shown, when the cross-sectional area of ​​the vehicle-side wire 3 is 95 mm2, it is confirmed that the temperature of the portion of the vehicle-side wire 3 100 cm away from the female terminal 21 is stable in both cases when the portion from the male terminal 11 to 100 cm is being cooled with water and when the portion is not being cooled with water (the effect of heat generation at the connection between the male terminal 11 and the female terminal 21 can be substantially ignored).

[0072] Furthermore, when the portion is being water-cooled, it was confirmed that the temperature of the portion of the vehicle-side wire 3 located 100 cm away from the female terminal 21 was stable when the cross-sectional area of ​​the vehicle-side wire 3 was either 70 mm2 or 95 mm2 (the effect of heat generation at the connection between the male terminal 11 and the female terminal 21 could be substantially ignored).

[0073] Based on the above results, it can be seen that by setting the length of the wire 200 to 2m or more, the heat generated at the connection between one male terminal 11 and one female terminal 21 can be negligibly affected by the wire on the connection between the other male terminal 11 and the other female terminal 21. Therefore, in this embodiment, the length of the wire 200 is set to 2m or more.

[0074] Each crimp terminal 300 is connected to the end 210 of the wire 200. Each crimp terminal 300 has a crimp portion 310 and a crimp side flange 320.

[0075] The crimping part 310 crimps the end 210 of the wire 200.

[0076] The crimping side flange 320 is connected to the crimping part 310. The crimping side flange 320 is formed flat. The crimping side flange 320 is provided with an insertion hole (not shown). The crimping side flange 320 is fixed to the female side flange 130 by bolt B and nut (not shown). 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.

[0077] The adjusting member 400 is capable of adjusting the contact resistance between the female terminal 100 and the male terminal 11. Specifically, the adjusting member 400 is capable of applying an external force to the female terminal 100 to reduce its diameter. The adjusting member 400 has an annular belt 410, a metal belt 420, and an adjusting section 430.

[0078] An annular strip 410 is mounted around the plurality of contact pieces 110. The annular strip 410 surrounds the entire circumference of the plurality of contact pieces 110. The annular strip 410 is made of a material (resin, etc.) that has electrical and thermal insulation properties. The length of the annular strip 410 in the direction parallel to the central axis A is smaller than the length of the slit 112S in that direction.

[0079] The metal strip 420 is wound around the annular strip 410. The metal strip 420 is capable of applying an external force to the plurality of contact pieces 110 of the female terminal 100 to the plurality of contact pieces 110, thereby reducing their diameter.

[0080] The adjusting part 430 is capable of adjusting the fastening force (the external force that causes the multiple contact pieces 110 to shrink in diameter) of the metal strip 420 on the plurality of contact pieces 110. Specifically, the adjusting part 430 adjusts the fastening force by adjusting the diameter of the metal strip 420. The adjusting part 430 has a screw capable of adjusting the diameter of the metal strip 420.

[0081] Next, an evaluation method for evaluating the cooling performance of the charging connector 5 using the evaluation fixture 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 fixture 50 to a pair of male terminals 11 of the male connector 10. This evaluation method includes a removal step, a connection step, an adjustment step, and an evaluation step.

[0082] The removal process is the process of removing a portion of the individual cylindrical walls 17 of the male connector sleeve 15. Specifically, as... Figures 14-16 As shown, in the removal process, a portion of each cylinder wall 17 is removed, creating an operating space 17S around the male terminal 11 that allows the adjustment unit 430 to perform the external force adjustment operation. This exposes a portion of each male terminal 11. Therefore, in the removal process, portions that can suppress short circuits between male terminals 11 or between male terminals 11 and other terminals 12-14 are removed; that is, portions other than the portions of a pair of cylinder walls 17 facing each other are removed. In this embodiment, the portion of the cylinder wall 17 outside the male terminal 11 in the direction connecting the male terminal 11 and the protective grounding terminal 12 is removed.

[0083] The connection process involves connecting a pair of female terminals 100 of the evaluation fixture 50 to a pair of male terminals 11. In this connection process, the female terminal 100 is connected to the male terminal 11 with an annular strip 410 and a metal strip 420 installed around the plurality of contact pieces 110 of each female terminal 100. For example... Figure 17 as well as Figure 18 As shown, in the connection process, the female terminal 100 is inserted until the front end 112a of each flexible piece 112 abuts against the surface 16S of the bottom wall 16 of the male connector sleeve 15. Additionally, in Figure 17 The image shows only the state where a female terminal 100 is inserted into a male terminal 11.

[0084] The adjustment process is a process of 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 generated by the metal strip 420) is adjusted by the adjustment part 430. More specifically, in the adjustment process, the external force is adjusted by operating the adjustment part 430 in the operating space 17S using an operating tool (not shown), so that the contact resistance between the male terminal 11 and the female terminal 100 falls within a specified range. In this process, for example, from... Figure 17Above, the tightening force of the adjusting part 430 is adjusted using the operating tool.

[0085] In the adjustment process, it is preferable to adjust the external force so that the contact resistance is 0.06mΩ or more and 0.15mΩ or less, and more preferably to adjust the external force so that the contact resistance is 0.08mΩ or more and 0.1mΩ or less.

[0086] Here, as Figure 18 As shown, the contact resistance is obtained by measuring the resistance between point P1, which is 4.5 mm away from the surface 16S of the bottom wall 16, and point P2, which is 43 mm away from the surface 16S of the bottom wall 16. This contact resistance can be measured using a milliohm meter or determined by the voltage drop when a current of 400 A is supplied. Furthermore, point P2 is located near the boundary between the area that influences and does not influence the design of the male connector 10 containing the male terminal 11.

[0087] In the evaluation process, the cooling performance is evaluated by checking whether the temperatures of the male terminal 11 and the female terminal 100 are below 90°C when a charging current of 400A is supplied for 30 minutes with the male terminal 11 and female terminal 100 connected. Furthermore, the temperatures of the male terminal 11 and the female terminal 100 can be detected by temperature sensors (not shown) installed on either the male terminal 11 or the female terminal 100.

[0088] As explained above, by using the evaluation fixture 50 of this embodiment, the heat generated when the charging connector 5 is powered on can be properly evaluated.

[0089] The exemplary implementations described above are specific examples of the following methods.

[0090] The evaluation fixture 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 a wire that connects the pair of female terminals to each other. The cross-sectional area of ​​the wire is 70 mm2 or more and 95 mm2 or less, and the length of the wire is 2 m or more.

[0091] In this evaluation fixture, since the cross-sectional area of ​​the wire is 70 mm² to 95 mm² and the length of the wire is 2 m or more, the heat generation (degree of temperature rise) at the connection between the male and female terminals can be properly evaluated when energized (during evaluation), with virtually no impact from the heat dissipation characteristics of the wire. Therefore, each terminal can be designed based on the evaluation results.

[0092] Furthermore, the wire is preferably made of copper.

[0093] Furthermore, the evaluation fixture 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 terminals. The female terminals can be reduced in diameter. The adjustment member has: an annular band that is mounted on the outer peripheral surface of the female terminals and formed to surround the female terminals; a metal band that is mounted on the outer peripheral surface of the annular band and can apply a force to the female terminals to reduce their diameter; and an adjustment portion that can adjust the fastening force of the metal band on the female terminals. The annular band is made of a material that has electrical insulation and thermal insulation properties.

[0094] Because the evaluation fixture has an adjustment section that can adjust the external force (fastening force) of the metal strip relative to the female terminal, the contact resistance between the male and female terminals can be adjusted. Furthermore, since the annular strip disposed between the female terminal and the metal strip is made of a material with both electrical and thermal insulation properties, heat dissipation from the metal strip to the adjustment section is suppressed. Therefore, the evaluation accuracy of suppressing heat generation at the connection between the male and female terminals is reduced.

[0095] Furthermore, the evaluation method of the above embodiment is to evaluate the cooling performance of the charging connector by connecting a pair of female terminals in an evaluation fixture that has a pair of male terminals capable of being cooled by a coolant to the pair of male terminals in the charging connector. This evaluation method includes: a connection step in which the pair of female terminals are connected to the pair of male terminals; an adjustment step in which the connection state between the male terminals and the female terminals is adjusted such 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 in which, after the adjustment step, the cooling performance is evaluated based on whether the temperature of the male terminals and the female terminals is 90°C or less when a charging current of 400A is supplied to the male terminals and the female terminals for 30 minutes.

[0096] In this evaluation method, since the contact resistance between the male and female terminals is specified to be within the range of 0.06 mΩ to 0.15 mΩ, deviations in the evaluation results are suppressed. Therefore, the cooling performance of the charging connector can be properly evaluated. Furthermore, by designing the female terminal of the charging socket such that the contact resistance is 0.06 mΩ to 0.15 mΩ, the temperature of the male and female terminals is below 90°C when a charging connector that has obtained a good evaluation result is charged for 30 minutes with a charging current of 400 A.

[0097] Furthermore, in the adjustment process, it is preferable to adjust the connection state so that the contact resistance is above 0.08mΩ and below 0.1mΩ.

[0098] Furthermore, the evaluation method of the above embodiment involves connecting a pair of female terminals in an evaluation fixture to the pair of male terminals in a charging connector that has a pair of male terminals that can be cooled by coolant and a bottom wall that holds the pair of male terminals when the pair of male terminals are inserted through it. This evaluation method includes: a connection step in which the pair of female terminals are connected to the pair of male terminals; and an adjustment step in which the connection state between the male terminals and the female terminals is adjusted so that the contact resistance between the male terminals and the female terminals falls within a specified range. In the adjustment step, the resistance between a point on the male terminal that is 4.5 mm away from the surface of the bottom wall and a point on the female terminal that is 43 mm away from the surface of the bottom wall is measured as the contact resistance.

[0099] In this evaluation method, since the measurement point for the contact resistance between the male and female terminals is determined, an appropriate evaluation result for cooling performance can be obtained. Specifically, the measurement point on the male terminal side is a point 4.5 mm away from the surface of the bottom wall. At this point, since the cross-sectional area of ​​the male terminal is sufficiently large, its influence on the contact resistance is small. Furthermore, the measurement point on the female terminal side is a point 43 mm away from the surface of the bottom wall. This point is near the boundary between the area that affects the standard when designing the charging connector containing the male terminal and the area that does not. Therefore, by designing the female terminal of the charging socket in a way that results in a contact resistance below that measured at this point, the temperature of both the male and female terminals during charging can be suppressed below a reference value when charging with a charging connector conforming to the standard.

[0100] Furthermore, in the evaluation method, it is preferable to include an evaluation step after the adjustment step, in which the cooling performance is evaluated based on whether the temperature of the male terminal and the female terminal is below 90°C when a charging current of 400A is supplied to the male terminal and the female terminal for 30 minutes.

[0101] Furthermore, the evaluation fixture 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 terminals. The female terminals can be reduced in diameter, and the adjustment member can apply an external force to the female terminals to reduce their diameter.

[0102] In this evaluation fixture, because the female terminal can be reduced in diameter, the adjusting member can apply an external force to the female terminal to reduce its diameter. Therefore, the contact resistance between the male and female terminals can be adjusted to fall within a specified range. Thus, the cooling performance of the charging connector can be properly evaluated.

[0103] Furthermore, the evaluation method of the above embodiment involves evaluating the cooling performance of a charging connector by connecting a pair of female terminals (which can be connected to the male terminals and can be reduced in diameter) and an adjustment member to the pair of male terminals of the charging connector, which has a pair of male terminals that can be cooled by coolant and a pair of cylindrical walls. The pair of cylindrical walls surround each of the male terminals, and the adjustment member applies an external force to each of the female terminals to reduce their diameter. The evaluation method includes: a removal step in which a portion of each of the cylindrical walls is removed to create an operating space around the male terminals, allowing the adjustment member to perform the adjustment of the external force; a connection step in which the pair of female terminals is connected to the pair of male terminals; and an adjustment step in which the external force is adjusted in the operating space by the adjustment member so that the contact resistance between the male terminals and the female terminals falls within a specified range.

[0104] In this evaluation method, since the operating space for adjusting external forces is formed around the male terminal, the contact resistance can be adjusted while the female terminal of the evaluation fixture is connected to the male terminal.

[0105] Furthermore, in the removal process, it is preferable to remove portions of the cylinder wall other than the portions of the pair of cylinder walls that are opposite each other.

[0106] This suppresses short circuits between the male terminals.

[0107] Alternatively, the adjusting member may include: an annular band mounted on the outer peripheral surface of the female terminal, forming an annulus surrounding the female terminal; a metal strip mounted on the outer peripheral surface of the annular band, capable of applying a force to the female terminal to reduce its diameter; and an adjusting portion capable of adjusting the tightening force of the metal strip on the female terminal, wherein the annular band is made of a material having electrical and thermal insulation properties. In this case, preferably, in the connection process, with the annular band and the metal strip installed on each female terminal, the pair of female terminals are connected to the pair of male terminals, and in the adjustment process, the tightening force of the metal strip on the female terminal is adjusted in the operating space.

[0108] Furthermore, the evaluation fixture of the above embodiment includes a female terminal capable of connecting to the male terminal of a charging connector. The female terminal has: a plurality of contact pieces, each capable of contacting the male terminal, arranged at intervals around a central axis; and a support portion supporting the plurality of contact pieces. Each of the plurality of contact pieces has: a flexible piece having a shape extending from the support portion in a direction parallel to the central axis; and a contact portion protruding from the inner surface of the flexible piece toward the central axis. The flexible piece forms part of a cylinder having the central axis. The length of the flexible piece in the direction parallel to the central axis is more than twice the outer diameter of the cylinder. The flexible piece is elastically deformable such that the front end of the flexible piece is displaced radially toward the cylinder relative to the base end, which serves as the connection between the flexible piece and the support portion. The contact portion has a shape that bends inwardly along the radial direction.

[0109] In this evaluation fixture, since the length of the flexible sheet in the direction parallel to the central axis is more than twice the outer diameter of the cylinder, plastic deformation of each flexible sheet is suppressed during repeated connection and removal of the female terminal from the male terminal. Furthermore, since each contact portion has a shape that bends in a radially inward manner, it maintains stable contact with the male terminal. Therefore, since the specified contact resistance is stably reproduced, the cooling performance of the charging connector can be properly evaluated.

[0110] Furthermore, it is preferable that the contact portion has a shape extending in a direction parallel to the central axis.

[0111] In this way, even when the female terminal is connected to the male terminal with its center axis tilted relative to the male terminal's center axis, the female terminal's posture can be guided in a way that aligns the two center axes.

[0112] Furthermore, it is preferable that the flexible sheet has a protrusion extending from the contact portion in a direction parallel to the central axis, away from the support portion.

[0113] Furthermore, it is preferable that the boundary between the flexible sheet and the contact portion has a curved shape.

[0114] In this case, it is preferable that the curvature of the top of the contact portion is smaller than the curvature of the boundary portion.

[0115] Furthermore, preferably, the flexible sheet has a facing surface opposite to the flexible sheet adjacent to it in the circumferential direction of the cylinder, and a set of facing surfaces that are opposite to each other in the circumferential direction are parallel to each other.

[0116] The embodiments of the present invention have been described above. However, it should be understood that all the embodiments disclosed herein are merely illustrative and not intended to limit the present invention. The scope of the present invention is indicated by the scope of protection of the claims, which is intended to include the same meaning as the scope of protection of the claims and all modifications within the scope of protection.

Claims

1. An evaluation fixture, It has evaluation terminals that can be connected to the male terminals of the connector. The evaluation terminal has: Multiple pieces, arranged at intervals around a central axis; and The protrusions protruding from the inner surfaces of each of the plurality of pieces The outer surface of the sheet is an arc surface centered on the central axis. The length of the sheet in the direction parallel to the central axis is more than four times the radius of curvature of the arc surface. The protrusion has a shape that curves inward in a radially inward manner along the arcuate surface. The protrusion has: The inner edge has a shape extending in a direction parallel to the central axis; and The connecting portion connects the inner edge portion to the inner surface of the piece. The connecting portion has a shape that is inclined in a direction parallel to the central axis, gradually approaching the inner surface of the sheet as it moves away from the inner edge.

2. The evaluation fixture according to claim 1, wherein, The radius of curvature of the boundary between the inner edge and the connecting portion is greater than the radius of curvature of the boundary between the connecting portion and the inner surface of the sheet.

3. The evaluation fixture according to claim 1, wherein, The radius of curvature of the boundary between the connecting part and the inner surface of the piece is 0.5 mm.

4. The evaluation fixture according to claim 1, wherein, The evaluation terminal also has a cylindrical portion, which is connected to the plurality of plates to form a cylindrical shape centered on the central axis.

5. The evaluation fixture according to claim 4, wherein, The evaluation terminal also has a flange that connects to the cylindrical portion. The flange has a shape that extends outward from the outer peripheral surface of the cylindrical portion in a direction orthogonal to the central axis.

6. The evaluation fixture according to claim 5, wherein, The length of the flange in the direction parallel to the central axis is the same as the length of the cylindrical portion in the direction parallel to the central axis.

7. The evaluation fixture according to claim 5, wherein, The flange is provided with an insertion hole.

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