Charging connector and method for setting drop impact value of charging connector

Abstract

The present invention addresses the problem of providing a charging connector having high impact resistance and a method for setting the drop impact value of the same.　A charging connector (1) comprises connection cylinder parts (4, 5). The connection cylinder parts (4, 5) have: cylinder part bodies (40, 50) which are made of a resin; and protective members (41, 51) which are made of an elastomer and cover at least portions of the leading ends (402, 502) of the cylinder part bodies (40, 50). The protective members (41, 51) are disposed in a collision part (C) that collides with a landing surface (E) when dropped. The von Mises stress generated in the collision part (C) when dropped is defined as drop impact values (σ1, σ2). The maximum value of the von Mises stress generated in a test piece when a load corresponding to a Charpy impact value specified by a prescribed standard of the resin forming the cylinder part bodies (40, 50) is applied to the test piece is defined as a fracture strength threshold (σth). The drop impact values (σ1, σ2) are set to be less than or equal to the fracture strength threshold (σth).

Description

Charging Connector and Method for Setting Drop Impact Value of Charging Connector

[0001] The present disclosure relates to, for example, a charging connector used for charging electric vehicles and a method for setting a drop impact value of the charging connector.

[0002] Patent Document 1 discloses a charging connector including a cylindrical metal connection cylinder (shell) and an annular rubber cover. When charging an electric vehicle, the connection cylinder is connected to a charging inlet of the electric vehicle. The rubber cover is locked to a distal end portion of the connection cylinder.

[0003] Japanese Unexamined Patent Publication No. Hei 7-57814

[0004] Generally, the impact resistance of a charging connector is ensured by a predetermined standard (and a test specified in the standard). Examples of such standards include the "Iron Ball Drop Test" in IEC 62196-1 "Plugs, socket-outlets, vehicle couplers and vehicle inlets - Conductive charging of electric vehicles - Part 1: General requirements".

[0005] The connection cylinder of the charging connector in the aforementioned document is made of metal. For this reason, it inherently has high impact resistance and is not easily damaged. In contrast, from the viewpoints of weight reduction and cost reduction, a connection cylinder made of resin instead of metal may be employed in some cases. Generally, a resin connection cylinder has lower impact resistance than a metal connection cylinder. For this reason, even charging connectors designed in compliance with the aforementioned standards are occasionally damaged in practice.

[0006] Accordingly, an object of the present disclosure is to provide a charging connector with high impact resistance. Another object of the present disclosure is to provide a method for setting a drop impact value of the charging connector.

[0007] (1) In order to solve the above problems, the charging connector of the present disclosure is a charging connector having a connecting part having a connecting cylindrical part that can be connected to and disconnected from the device-side connector of a device to be charged, wherein the connecting cylindrical part has a resin cylindrical body and an elastomer protective member that covers at least a part of the tip of the cylindrical body, wherein the protective member is placed on an impact part that collides with the surface when the charging connector falls, and the drop impact value is set to be less than or equal to the fracture strength threshold, with the von Mises stress generated on the impact part when it falls being the drop impact value, and the maximum value of the von Mises stress generated on the test piece when a load corresponding to the Charpy impact value specified in a predetermined standard for the resin is applied to the test piece according to the standard being the fracture strength threshold.

[0008] Here, "elastomer" refers to an elastic material (thermosetting elastomer, photocurable elastomer, thermoplastic elastomer, rubber, etc.) whose main component is an organic material, and which is different from the material of the "resin" that forms the main body of the cylindrical part. Furthermore, the "standards" that specify the Charpy impact value include national standards such as JIS, ANSI, GB / T, AS, and DIN, as well as international standards such as ISO.

[0009] In this configuration, the drop impact value of the charging connector is set to be below the breaking strength threshold. Therefore, even though the cylindrical body is made of resin, it is possible to mitigate the impact of drops and suppress damage to the charging connector. Thus, this configuration makes the impact resistance of the charging connector high.

[0010] (1-1) In the configuration of (1) above, the resin may be a fiber-reinforced resin. This configuration makes it possible to increase the impact resistance of the connecting cylinder portion.

[0011] (1-2) In any of the above configurations, the fiber-reinforced resin may be PA (polyamide) 66-GF (glass fiber) 25. This configuration makes it possible to improve the impact resistance, dimensional stability, heat resistance, and electrical insulation of the connecting cylinder portion.

[0012] (1-3) In any of the above configurations, the protective member may be integrated with the cylindrical body. This configuration makes it possible to suppress the separation of the protective member and the cylindrical body. Note that "integration" includes forms in which the cylindrical body and the protective member are integrally molded (insert molded) or forms in which the protective member is bonded to the cylindrical body.

[0013] (2) In any of the above configurations, the standard in which the Charpy impact value is defined may be JIS K 7111. With this configuration, a fracture strength threshold in accordance with JIS can be set.

[0014] (3) In any of the above configurations, the thickness of the protective member may be 3 mm or more. With this configuration, damage to the charging connector due to dropping can be suppressed compared to the case where the thickness is less than 3 mm. In particular, damage to the charging connector due to dropping can be suppressed in the case of the CCS (Combined Charging System) type 1 and CCS type 2 charging connectors, which have a large mass.

[0015] (3-1) In any of the above configurations, the thickness of the protective member may be 6.0% or more and 25.0% or less, with the axial total length of the connecting cylinder portion being 100%. With this configuration, damage to the charging connector due to dropping can be suppressed compared to the case where the thickness of the protective member is less than 6.0%. Furthermore, with this configuration, the frictional force of the elastomer protective member against the device-side connector can be reduced compared to the case where the thickness of the protective member exceeds 25.0%. Therefore, the insertion and removal of the connecting cylinder portion from the device-side connector can be simplified.

[0016] (4) In any of the above configurations, the hardness of the elastomer may be 50 degrees or more and 90 degrees or less. Here, "hardness" refers to the durometer type A hardness of JIS K 6253.

[0017] This configuration allows for mitigating the impact of a fall and suppressing damage to the charging connector compared to cases where the hardness is less than 50 degrees. Furthermore, this configuration allows for mitigating the impact of a fall and suppressing damage to the charging connector compared to cases where the hardness exceeds 90 degrees. In addition, it improves the processability (e.g., moldability, adhesiveness, etc.) of the protective member relative to the cylindrical body.

[0018] (4-1) In the configuration of (4) above, the hardness of the elastomer may be 60 degrees or higher. With this configuration, compared to the case where the hardness is less than 60 degrees, the impact of dropping can be further mitigated and damage to the charging connector can be suppressed.

[0019] (5) In any of the above configurations, the connector may be configured to include a connector body and a plurality of connecting cylindrical parts corresponding to the same charging connector standard, wherein the plurality of connecting cylindrical parts are interchangeably connected to the connector body.

[0020] Here, "charging connector standards" include CHAdeMO®, TYPE1-SAEJ1772, TYPE2-IEC62196-2, CCS1, CCS2, TESLA, GB / T20234.2, GB / T20234.3, etc.

[0021] With this configuration, if the connecting cylinder is damaged, only that connecting cylinder, or the entire connector containing that connecting cylinder, can be replaced. Therefore, replacement costs can be reduced compared to replacing the entire charging connector.

[0022] (6) In any of the above configurations, a chamfered portion covered by the protective member may be provided at the corner of the tip of the cylindrical body. Here, the "chamfered portion" includes flat C-shaped chamfered portions and curved R-shaped chamfered portions.

[0023] According to this configuration, the chamfered portion can mitigate the concentration of stress on the impact point (chamfered portion) when the charging connector is dropped. Therefore, damage to the charging connector can be suppressed. In addition, when the protective member is bonded to the cylindrical body, the chamfered portion can increase the bonding area between the cylindrical body and the protective member. Therefore, the adhesion between the cylindrical body and the protective member can be improved.

[0024] (7) In any of the above configurations, the charging connector standard is CCS2, and the connecting portion has a short-axis cylindrical portion and a long-axis cylindrical portion having a longer axial length than the short-axis cylindrical portion as the connecting cylindrical portion, and when in use, the short-axis cylindrical portion is positioned above the long-axis cylindrical portion, and the protective member is positioned on at least a part of the upper portion of the outer peripheral edge of the tip of the cylindrical body of the short-axis cylindrical portion.

[0025] Here, the "upper portion" refers to the portion above the center of gravity of the outer edge of the tip of the short-axis cylindrical body, when viewed from the axial direction of the cylindrical body. This configuration makes it possible to suppress damage to the charging connector, especially when the charging connector falls upside down.

[0026] In particular, when the configuration described in (6) above is combined with this configuration (specifically, when a chamfered portion is placed on the "upper part" of this configuration and a protective member is placed covering the chamfered portion), and when the protective member is bonded to the cylindrical body, the chamfered portion can increase the bonding area between the cylindrical body and the protective member. This improves the adhesion between the cylindrical body and the protective member.

[0027] (8) In any of the above configurations, the charging connector standard is CCS2, and the connecting portion has a short-axis cylindrical portion and a long-axis cylindrical portion having a longer axis length than the short-axis cylindrical portion as the connecting cylindrical portion, and when in use, the long-axis cylindrical portion is positioned below the short-axis cylindrical portion, and the protective member is positioned on at least a part of the lower outer edge of the tip of the cylindrical body of the long-axis cylindrical portion.

[0028] Here, the "lower portion" refers to the portion below the center of gravity of the outer edge of the tip of the long-axis cylindrical body, when viewed from the axial direction of the cylindrical body. With this configuration, damage to the charging connector can be suppressed, especially if the charging connector is dropped without being inverted.

[0029] In particular, when the configuration described in (6) above is combined with this configuration (specifically, when a chamfered portion is placed on the "lower part" of this configuration, and a protective member is placed to cover the chamfered portion), and when the protective member is bonded to the cylindrical body, the chamfered portion can increase the bonding area between the cylindrical body and the protective member. This improves the adhesion between the cylindrical body and the protective member.

[0030] (9) In order to solve the above problems, the method for setting the drop impact value of a charging connector of the present disclosure is a method for setting the drop impact value of a charging connector having a connecting part having a connecting cylindrical part that can be connected to and from the device-side connector of a device to be charged, wherein the connecting cylindrical part has a resin cylindrical body and an elastomer protective member that covers at least a part of the tip of the cylindrical body, and the protective member is placed on the impact part that collides with the falling surface when the charging connector is dropped, and when a Charpy impact test is simulated to cause impact fracture using FEM analysis, the von Mises stress generated in the test piece is The method is characterized by comprising: a step of acquiring a fracture strength threshold by acquiring the maximum value and setting the maximum value as the fracture strength threshold; a step of acquiring a drop impact value by acquiring the von Mises stress generated at the impact point when the analysis model of the charging connector is simulated to drop using FEM analysis and setting the von Mises stress as the drop impact value; a comparison step of comparing the fracture strength threshold and the drop impact value; and an impact mitigation characteristic adjustment step of adjusting the impact mitigation characteristics of the protective member so that the drop impact value becomes less than or equal to the fracture strength threshold if the drop impact value exceeds the fracture strength threshold.

[0031] Here, "elastomer" refers to an elastic material (thermosetting elastomer, photocurable elastomer, thermoplastic elastomer, rubber, etc.) whose main component is an organic material, and is different from the material of the "resin" that forms the main body of the cylindrical part. Furthermore, "impact mitigation characteristics of the protective member" include the thickness of the protective member, the structure of the protective member (e.g., a structure with high cushioning and impact resistance), and the hardness of the elastomer forming the protective member. Furthermore, "charging connector" includes a charging connector having any of the configurations (1) to (8) above.

[0032] In this configuration, the fracture strength threshold obtained in the fracture strength threshold acquisition step is compared with the drop impact value obtained in the drop impact value acquisition step in the comparison step. If the comparison result is "drop impact value > fracture strength threshold," that is, if there is a high possibility that the charging connector will be damaged by a fall, the impact mitigation characteristic adjustment step adjusts the impact mitigation characteristics of the protective member to reduce the drop impact value of the charging connector so that "drop impact value ≤ fracture strength threshold." Therefore, the impact resistance of the charging connector can be increased.

[0033] (9-1) In the configuration of (9) above, in the step of acquiring the drop impact value, the drop height of the impact part relative to the drop surface may be set to 1 m, and the mass of the analysis model may be set to the maximum mass among the masses of multiple charging connectors corresponding to the same charging connector standard.

[0034] The mass of the analysis model is set to the maximum mass among multiple charging connectors that conform to the same charging connector standard (the charging connector being analyzed by the analysis model). Therefore, the drop impact value obtained in the drop impact value acquisition step becomes large. On the other hand, the fracture strength threshold does not depend on the mass of the charging connector, i.e., the analysis model. Therefore, the drop impact value is likely to exceed the fracture strength threshold. Consequently, the charging connector is more likely to break.

[0035] This configuration deliberately sets conditions that tend to result in a large drop impact (making the charging connector more susceptible to damage), and then adjusts the impact mitigation characteristics of the protective material so that the drop impact value remains below the breaking strength threshold. As a result, damage to the charging connector can be suppressed more reliably.

[0036] (10) In the configuration of (9) or (9-1) above, the straight line connecting the center of gravity of the analysis model and the collision part is defined as the collision line, and the angle of intersection between the falling surface and the collision line is defined as the falling angle. In the step of acquiring the falling impact value, the falling posture of the analysis model may be set such that the falling angle approaches 90° and the area of ​​the collision part becomes smaller.

[0037] By bringing the drop angle closer to 90° (of course, the drop angle can be 90°), it is possible to suppress the distribution of the load applied to the impact point during the collision in the planar direction (the direction in which the falling surface extends). Therefore, the load applied to the impact point can be increased. Also, by reducing the area of ​​the impact point (the contact area of ​​the analytical model with the falling surface), the stress applied to the impact point can be increased.

[0038] Thus, this configuration deliberately sets conditions that tend to result in a large drop impact (making the charging connector more susceptible to damage), and adjusts the impact mitigation characteristics of the protective material so that the drop impact value remains below the breaking strength threshold. Therefore, damage to the charging connector can be suppressed more reliably.

[0039] (10-1) In the configuration of (10) above, the falling angle in the falling posture may be within 90° ± 30°. With this configuration, compared to the case where the falling angle exceeds 90° ± 30°, it is possible to suppress the dispersion of the load applied to the impact part in the planar direction during the collision. Therefore, the load applied to the impact part can be increased.

[0040] (11) In any of the configurations described in (9) to (10-1) above, the fracture strength threshold acquisition step may involve applying a load to the test piece that corresponds to the Charpy impact value specified in a predetermined standard for the resin. With this configuration, the fracture strength threshold can be obtained based on the Charpy impact value specified in a predetermined standard for the resin forming the cylindrical body.

[0041] (12) In the configuration of (11) above, the standard in which the Charpy impact value is defined may be JIS K 7111. With this configuration, a fracture strength threshold in accordance with JIS can be set.

[0042] (13) In any of the configurations described in (9) to (12) above, the impact mitigation characteristic may be the thickness of the protective member. With this configuration, damage to the charging connector can be suppressed by adjusting (increasing) the thickness of the protective member.

[0043] According to the charging connector of this disclosure, the impact resistance of the charging connector can be increased even though the cylindrical body is made of resin. Furthermore, according to the method for setting the drop impact value of the charging connector of this disclosure, it is possible to design a charging connector with high impact resistance.

[0044] FIG. 1 is a perspective view of a charging connector according to a first embodiment. FIG. 2 is a right side view of the charging connector. FIG. 3 is a front view of the charging connector. FIG. 4 is an enlarged cross-sectional view within circle IV of FIG. 2. FIG. 5 is a flowchart showing a method for setting a drop impact value of the charging connector according to the first embodiment. FIG. 6 is a graph showing chronological changes in Mises stress generated on a fracture surface of a test piece. FIG. 7 is a side view of an analysis model. FIG. 8 is a right side view showing a first posture in a drop posture setting step of the analysis model. FIG. 9 is a right side view showing a second posture in the step of the analysis model. FIG. 10 is a front view showing the second posture in the step of the analysis model. FIG. 11 is a front view showing a third posture in the step of the analysis model. FIG. 12 is a schematic diagram of a calculation step of the analysis model. FIG. 13 is a graph showing chronological changes in a drop impact value of the analysis model. FIG. 14 is a front view of a charging connector according to a second embodiment. FIG. 15 is a front view of a charging connector according to a third embodiment.

[0045] Hereinafter, embodiments of the charging connector and the method for setting a drop impact value of the charging connector according to the present disclosure will be described.

[0046] <First Embodiment> FIG. 1 shows a perspective view of the charging connector according to the present embodiment. FIG. 2 shows a right side view (lateral view) of the charging connector. FIG. 3 shows a front view (front elevation) of the charging connector. FIG. 4 shows an enlarged cross-sectional view within circle IV of FIG. 2. The orientations (up, down, front, back, left, right) in FIGS. 1 to 4 are set based on when the charging connector 1 is in use. In addition, in FIGS. 1 to 3 (external views), hatching is applied to protection members 41 and 51 for convenience of explanation.

[0047] (Configuration of Charging Connector 1) First, the configuration of the charging connector 1 according to the present embodiment will be described. The charging connector 1 is for an electric vehicle (not shown). The charging connector 1 is attachable to and detachable from a charging inlet of an electric vehicle. The electric vehicle is included in the concept of the "device to be charged" in the present disclosure. The charging inlet is included in the concept of the "device-side connector" in the present disclosure.

[0048] The charging connector 1 of this embodiment is a CCS2 type charging connector. That is, the charging connector 1 conforms to the CCS2 standard. The charging connector 1 comprises a connector body 2 and a connection part 3.

[0049] As shown in Figure 3, the charging connector 1 is provided with a pair of left and right impact parts C. On the entire outer surface of the charging connector 1, the impact parts C are the parts that are expected to make contact with the falling surface at the fastest speed, before other parts, when the charging connector 1 is dropped. The impact parts C will be described later.

[0050] (Connector body 2) The connector body 2 includes a housing 20. The housing 20 is made of resin and has a box shape. The housing 20, the cylindrical body 40 of the short-axis cylindrical portion 4 (described later), and the cylindrical body 50 of the long-axis cylindrical portion 5 are all made of the same resin (PA66-GF25 in this embodiment) and are a single piece. PA66-GF25 is a fiber-reinforced resin, a polyamide containing 25% glass fiber. The housing 20 constitutes the outer shell of the connector body 2. Various electronic components (for example, a converter, inverter, transformer, rectifier circuit, etc.) are housed inside the housing 20.

[0051] A grip portion 200 is positioned on the upper rear part of the housing 20. When in use, the grip portion 200 is held by the user. A charging cable 90 is connected to the rear end (root end; user-side end) of the housing 20.

[0052] (Connection part 3) The connection part 3 is located on the front end surface of the housing 20 (the end opposite to the base end; the end on the charging inlet side). The connection part 3 is removable from the charging inlet of the electric vehicle. The connection part 3 comprises a short shaft cylindrical portion 4 and a long shaft cylindrical portion 5.

[0053] (Long shaft cylindrical portion 5) The long shaft cylindrical portion 5 comprises a cylindrical body 50 and a protective member 51. The cylindrical body 50 protrudes from the front end of the housing 20. The cylindrical body 50 is made of resin and has a long shaft cylindrical shape that extends in the front-rear direction. A charging pin 500 is arranged inside the cylindrical body 50.

[0054] As shown in Figure 4, a chamfered portion 501 is provided on the outer peripheral edge 503 of the tip portion 502 of the cylindrical body 50 (more specifically, the corner between the tip surface 504 and the outer peripheral surface 505 of the cylindrical body 50). The chamfered portion 501 has a C-shaped chamfer.

[0055] The protective member 51 is made of elastomer (silicone rubber in this embodiment) and covers the outer peripheral edge 503 (including the chamfered portion 501) from the outside. The protective member 51 is integrally laminated on the tip surface 504 and the outer peripheral edge 503.

[0056] A chamfered portion 511 is provided on the outer peripheral edge 513 of the protective member 51 (more specifically, the corner between the tip surface 514 and the outer peripheral surface 515 of the protective member 51). The chamfered portion 511 has a C-shaped chamfer. The chamfered portion 511 is located in front of the chamfered portion 501. As shown in Figure 3, the protective member 51 covers the pair of collision portions C from the front (outside).

[0057] (Short-axis cylindrical portion 4) The short-axis cylindrical portion 4 comprises a cylindrical body 40 and a protective member 41. The cylindrical body 40 protrudes from the front end of the housing 20. The cylindrical body 40 is arranged side by side above the cylindrical body 50. The cylindrical body 40 and the cylindrical body 50 are connected in the vertical direction. The cylindrical body 40 is made of resin and has a short-axis cylindrical shape that extends in the front-rear direction. The cylindrical body 40 has a shorter axial length than the cylindrical body 50. A charging pin 400 is arranged inside the cylindrical body 40. Similar to the chamfered portion 501 of the cylindrical body 50 shown in Figure 4, a C-shaped chamfered portion is arranged on the outer circumferential edge of the tip portion 402 of the cylindrical body 40.

[0058] The arrangement and configuration of the protective member 41 are the same as those of the protective member 51 described above. The protective member 41 is made of elastomer (silicone rubber in this embodiment) and covers the outer peripheral edge (including the chamfered portion; see outer peripheral edge 503 in Figure 4) of the cylindrical body 40 from the outside. The protective member 41 is integrally laminated on the front surface (see front surface 504 in Figure 4) and outer peripheral edge of the cylindrical body 40. Similar to the chamfered portion 511 of the protective member 51 shown in Figure 4, a C-shaped chamfered portion 411 is arranged on the outer peripheral edge 413 of the protective member 41.

[0059] (Method for setting the drop impact value of the charging connector) Next, the method for setting the drop impact value of the charging connector 1 of this embodiment (hereinafter referred to as "setting method" as appropriate) will be described. The setting method is performed at the design stage of the charging connector 1 in order to manufacture a charging connector 1 with a small drop impact value (high impact resistance). Simulation analysis (FEM (finite element method) analysis) is used for the setting method. The FEM analysis is performed using Ansys LS-DYNA (collision simulation software). The explicit method is used for the FEM analysis. No constraint conditions are defined.

[0060] Figure 5 shows a flowchart of the setting method of this embodiment. As shown in Figure 5, the setting method of this embodiment includes a fracture strength threshold acquisition step S1, a drop impact value acquisition step S2, a comparison step S3, and an impact mitigation characteristic adjustment step S4. In Figure 5, the drop impact values ​​σ1 and σ2, which will be described later, are collectively referred to as the drop impact value "σ".

[0061] (Step S1 for obtaining fracture strength threshold) In this step, a Charpy impact test is simulated to obtain a fracture strength threshold for evaluating the drop impact value described later. Specifically, the Charpy impact value (= 68 kJ / m) of PA66-GF25 (material for the cylindrical body 40, 50 and housing 20) is obtained for a JIS K 7111 test piece. ２ The history of von Mises stress generated on the fracture surface of a test specimen will be analyzed when a load equivalent to that applied is applied. The dimensions of the test specimen are "length 80 mm x width 10 mm x thickness 4.0 mm". No notches are placed on the test specimen.

[0062] Figure 6 shows a graph of the time-series change in von Mises stress generated on the fracture surface of the test specimen. As shown in Figure 6, the von Mises stress on the tensile side (opposite the hammer contact side) is smaller than the von Mises stress on the contact side, i.e., the compression side (hammer contact side). In this step, the maximum value of the tensile von Mises stress is adopted as the fracture strength threshold σth. The reason for adopting the maximum value of the tensile von Mises stress, rather than the contact side, i.e., the compression side, as the fracture strength threshold σth is that objects are generally weaker against tensile stress than against compressive stress, and the initiation point that triggers fracture is often generated by tensile stress at a microscopic level.

[0063] (Step S2 for acquiring drop impact value) In this step, an analysis model simulating a commercially available charging connector is created, and the drop impact value σ1 is calculated when the analysis model is dropped in a predetermined dropping position (the dropping position in which the analysis model is considered most likely to be damaged). As shown in Figure 5, this step comprises an analysis model creation step S20, a drop position setting step S21, and a calculation step S22.

[0064] (Analysis Model Creation Step S20) In this step, an analysis model is created. The analysis model is created assuming a commercially available charging connector of the same standard (CCS2 type). Figure 7 shows a side view of the analysis model. Note that parts corresponding to those in Figure 2 are indicated by the same reference numerals. As shown in Figure 7, analysis model 1 has the same configuration as the charging connector 1 shown in Figure 2, with the protective members 41 and 51 removed. Table 1 shows the specifications of analysis model 1.

[0065] The mass of several commercially available charging connectors of the same specifications is approximately 500g to 800g. Based on this assumption, the mass of analysis model 1 shown in Table 1 is designed to be 627.8637g (the sum of the mass of the connection part 3 (169.0637g) and the mass of the connector body 2 (458.8g)).

[0066] (Falling posture setting step S21) In this step, the falling posture of the analysis model 1 shown in Figure 7 is set so that the falling angle, which will be described later, approaches 90°, and the area of ​​the impact part C (the contact area of ​​the analysis model 1 with the falling surface at the time of impact) is reduced.

[0067] Figure 8 shows the right side view of the first posture of this step of the analysis model. Figure 9 shows the right side view of the second posture of this step of the analysis model. Figure 10 shows the front view of the second posture of this step of the analysis model. Figure 11 shows the front view of the third posture of this step of the analysis model.

[0068] First, as shown in Figure 8, the analysis model 1 is set to the first position. The first position is the position in which the cylindrical axes of the connecting part 3 (short-axis cylindrical part 4 and long-axis cylindrical part 5) are oriented vertically (the position in which the connecting part 3 is at a 90° angle to the falling surface E). The long-axis cylindrical part 5 has a longer axis than the short-axis cylindrical part 4. Therefore, in the first position, the annular tip surface 504 of the long-axis cylindrical part 5 makes surface contact with the falling surface E. The impact point C is the tip surface 504.

[0069] Next, in order to reduce the area of ​​the impact point C, the analysis model 1 is switched from the first posture to the second posture, as shown in Figures 8 and 9. Specifically, the analysis model 1 is tilted by a predetermined tilt angle around the X-axis (left-right axis). In the second posture, the trailing edge (part of the outer peripheral edge 503) 503a of the tip surface 504 makes line contact with the falling surface E. The impact point C is the trailing edge 503a.

[0070] Furthermore, it is also possible to define a second posture as one in which the object is tilted in the opposite direction (forward) to the tilting direction (rearward) shown in Figure 9. In the case of analysis model 1 of this analysis, the long-axis cylinder 5 is the longer axis than the short-axis cylinder 4, and it is assumed that in the event of a collision, the long-axis cylinder 5 will often contact the landing surface E earlier than the short-axis cylinder 4. For this reason, in this analysis, analysis model 1 is tilted in the direction shown in Figure 9.

[0071] Next, in order to further reduce the area of ​​the impact point C, the analysis model 1 is switched from the second posture to the third posture, as shown in Figures 10 to 11. Specifically, the analysis model 1 is tilted by a predetermined tilt angle around the Y-axis (forward-backward axis). In the third posture, a portion 503b of the trailing edge (part of the outer peripheral edge 503) 503a of the front end surface 504 makes point contact with the falling surface E. The impact point C is the portion 503b of the trailing edge 503a.

[0072] It is also possible to define a third posture as the analysis model 1 tilted in the opposite direction (to the right) to the tilting direction (to the left) shown in Figure 11. However, the analysis results are the same regardless of whether it is tilted to the left or right. Therefore, in this analysis, the analysis model 1 is tilted in the direction shown in Figure 11.

[0073] Next, we verify the third posture shown in Figure 11. Specifically, we define the line connecting the center of gravity G of analysis model 1 and the impact point C as the impact line L, and the angle of intersection between the falling surface E and the impact line L as the falling angle θ (which includes not only the angle around the Y axis shown in Figure 11, but also the angle around the X axis shown in Figure 8). We then verify whether the falling angle θ is within the range of 90° ± 30°.

[0074] If the drop angle θ is within the specified range, the third posture is set to the drop posture of analysis model 1. If the drop angle θ exceeds the specified range, the third posture is corrected so that the drop angle θ falls within the specified range. The corrected posture is set to the drop posture of analysis model 1. In this way, in this step, analysis model 1 is set to the drop posture that is assumed to be most susceptible to damage.

[0075] (Calculation Step S22) Figure 12 shows a schematic diagram of this step of the analysis model. In this step, the fall impact value applied to the analysis model 1 is calculated by simulating the case where the analysis model 1 is dropped from a predetermined fall height H (=1m) in the fall posture described above.

[0076] Specifically, the analysis model 1 is placed 2 mm (= 0.002 m) above the landing surface E (in the air), and the initial velocity of the analysis model 1 is set to the velocity at which it will fall from 0.998 m (= 1 m - 0.002 m), thereby simulating the falling condition from a landing height H (= 1 m) shown in Figure 12. Note that air resistance during the fall is not considered. In addition, gravitational acceleration (1G) is constantly applied to the analysis model 1. A von Mises stress is generated at the impact point C due to the collision. This von Mises stress is defined as the impact value σ1.

[0077] (Comparison Step S3) In this step, the fracture strength threshold σth obtained in the fracture strength threshold acquisition step is compared with the drop impact value σ1 obtained in the drop impact value acquisition step. If the drop impact value σ1 exceeds the fracture strength threshold σth as a result of the comparison, it is determined that "there is a high possibility that analysis model 1 will be damaged." Conversely, if the drop impact value σ1 is less than or equal to the fracture strength threshold σth, it is determined that "there is a low possibility that analysis model 1 will be damaged."

[0078] Figure 13 shows a graph of the time-series change in the drop impact value of the analysis model. The graph shows the fracture strength threshold σth shown in Figure 6, the drop impact value σ1, and the drop impact value σ2 after the impact mitigation characteristic adjustment step S4 described later.

[0079] As shown in Figure 13, the drop impact value σ1 instantaneously exceeds the fracture strength threshold σth. Therefore, in this step, it is determined that "there is a high probability that analysis model 1 will be damaged."

[0080] (Impact Mitigation Characteristic Adjustment Step S4) In this step, protective members 41 and 51 (see Figures 1 to 4) with a predetermined thickness (3 mm) are placed in the initial analysis model 1 so that the drop impact value σ1 is less than or equal to the fracture strength threshold σth. The arrangement of the protective members 41 and 51 changes the mass, center of gravity, etc. of the analysis model 1 created in the analysis model creation step S20 shown in Figure 5. For this reason, the analysis model 1 is updated in this step.

[0081] Here, in order to ensure easy insertion and removal from the electric vehicle's charging inlet, the axial lengths of the short-axis cylindrical section 4 and the long-axis cylindrical section 5 remain unchanged before and after the update, regardless of the presence or absence of the protective members 41 and 51. For this reason, in the updated analysis model 1, the axial lengths of the cylindrical sections 40 and 50 are set shorter than in the pre-update analysis model 1 by the amount by which the protective members 41 and 51 are placed.

[0082] Subsequently, as shown in Figure 5, the drop posture setting step S21 and calculation step S22 are executed again to obtain the drop impact value σ2 of the updated analysis model 1. Next, the comparison step S3 is executed to compare the fracture strength threshold σth with the drop impact value σ2. As shown in Figure 13, the drop impact value σ2 is below the fracture strength threshold σth. Therefore, in the second comparison step S3, it is determined that "the possibility of analysis model 1 being damaged is low." Based on this analysis model 1, a charging connector 1 (specifically, a charging connector equipped with protective members 51 that cover a pair of left and right collision parts C) is designed and manufactured.

[0083] (Effects) Next, the effects of the charging connector and the method for setting the drop impact value of the charging connector in this embodiment will be explained. As shown in Figure 13, the drop impact value σ2 of the charging connector (analysis model) 1 is set to be less than or equal to the fracture strength threshold σth. Therefore, even though the cylindrical body parts 40 and 50 are made of resin, the impact caused by drops can be mitigated and damage to the charging connector 1 can be suppressed. In this way, according to this embodiment, the impact resistance of the charging connector 1 can be increased.

[0084] Furthermore, the cylindrical body sections 40 and 50 are made of fiber-reinforced resin (PA66-GF25). This allows for high impact resistance, dimensional stability, heat resistance, and electrical insulation of the short-axis cylindrical section 4 and the long-axis cylindrical section 5.

[0085] Furthermore, the protective member 41 is integrated with the cylindrical body 40 by insert molding. Specifically, the raw material for the protective member 41 is injected into the cavity of a mold in which the cylindrical body 40 is already placed, and cured, thereby molding the protective member 41 and bonding it to the cylindrical body 40. As a result, the protective member 41 is less likely to peel off from the cylindrical body 40.

[0086] In step S1, which is shown in Figure 5, the fracture strength threshold σth is obtained using the Charpy impact value specified in JIS K 7111. Therefore, it is possible to set a fracture strength threshold σth that conforms to JIS standards.

[0087] In the impact mitigation characteristic adjustment step S4 shown in Figure 5, the thickness of the protective member 51 is set to 3 mm. The same applies to the thickness of the protective members 41 and 51 shown in Figure 1. Therefore, compared to the case where the thickness is less than 3 mm, damage to the charging connector 1 due to dropping can be suppressed. In particular, the CCS2 type charging connector 1 is heavy. Therefore, damage to the charging connector 1 due to dropping can be suppressed more effectively.

[0088] In the impact mitigation characteristic adjustment step S4 shown in Figure 5, the axial length of the long shaft cylindrical portion 5 is set to 100%, and the thickness of the protective member 51 is set to 6.0% or more and 25.0% or less. The same applies to the thickness of the protective members 41 and 51 shown in Figure 1. As a result, damage to the charging connector 1 due to dropping can be suppressed compared to the case where the thickness is less than 6.0%. Also, compared to the case where the thickness exceeds 25.0%, the frictional force of the elastomer protective members 41 and 51 against the charging inlet of the electric vehicle can be reduced. Therefore, the insertion and removal of the short shaft cylindrical portion 4 and the long shaft cylindrical portion 5 into and out of the charging inlet can be simplified.

[0089] The hardness (durometer type A hardness) of the elastomer (silicone rubber) forming the protective members 41 and 51 shown in Figure 1 is set to 50 degrees or more and 90 degrees or less. Therefore, compared to the case where the hardness is less than 50 degrees, when the charging connector 1 is dropped, the impact of the fall is mitigated and damage to the charging connector 1 can be suppressed. Also, compared to the case where the hardness exceeds 90 degrees, when the charging connector 1 is dropped, the impact of the fall is mitigated and damage to the charging connector 1 can be suppressed. In addition, the processability (e.g., moldability, adhesiveness, etc.) of the protective members 41 and 51 relative to the cylindrical body 40 and 50 can be improved. Furthermore, the hardness of the elastomer described above is set to 60 degrees or more. Therefore, compared to the case where the hardness is less than 60 degrees, the impact of the fall is further mitigated and damage to the charging connector 1 can be suppressed.

[0090] As shown in Figure 4, the protective member 51 covers the chamfered portion 501 at the corner of the tip portion 502 of the cylindrical body 50. Therefore, if the chamfered portion 501 corresponds to the impact portion C, it is possible to mitigate the concentration of stress at the impact portion C when the charging connector 1 is dropped. Thus, damage to the charging connector 1 can be suppressed. In addition, if the protective member 51 is bonded to the cylindrical body 50, the chamfered portion 501 can increase the bonding area between the cylindrical body 50 and the protective member 51. Therefore, the adhesion between the cylindrical body 50 and the protective member 51 can be improved.

[0091] As shown in Figure 5, according to the setting method of this embodiment, the fracture strength threshold σth obtained in the fracture strength threshold acquisition step S1 and the drop impact value σ1 obtained in the drop impact value acquisition step S2 are compared in the comparison step S3. If the comparison result is "drop impact value σ1 > fracture strength threshold σth", that is, if there is a high possibility that the analysis model 1 (charging connector 1) will be damaged by a fall, the impact mitigation characteristics of the protective member 51 are adjusted in the impact mitigation characteristics adjustment step S4. Specifically, a protective member 51 with a predetermined thickness (3 mm) is placed. The protective member 51 can update the drop impact value σ1 to a smaller drop impact value σ2. As a result, it is possible to make "drop impact value σ2 ≤ fracture strength threshold σth". Therefore, the impact resistance of the charging connector 1 can be increased.

[0092] In the drop impact value acquisition step S2 shown in Figure 5, the drop posture of the analysis model 1 is set such that the drop angle θ approaches 90° and the area of ​​the impact part C is reduced, as shown in Figures 8 to 11.

[0093] By bringing the drop angle θ closer to 90° (of course, the drop angle θ = 90°), it is possible to suppress the distribution of the load applied to the impact area C during the collision in the planar direction (the direction of extension of the falling surface E). Therefore, the load applied to the impact area C can be increased. Also, by reducing the area of ​​the impact area C (the contact area of ​​the analysis model 1 with respect to the falling surface E), the stress applied to the impact area C can be increased.

[0094] Thus, according to this embodiment, conditions are deliberately set that tend to result in a large drop impact value σ1 (making the charging connector 1 prone to damage), and the impact mitigation characteristics of the protective member 51 are adjusted so that the drop impact value σ1 is less than or equal to the fracture strength threshold σth (resulting in a drop impact value of σ2). Therefore, damage to the charging connector 1 can be suppressed more reliably.

[0095] As shown in Figure 11, the drop angle θ in the falling posture is set to within 90° ± 30°. Therefore, compared to the case where the drop angle θ exceeds 90° ± 30°, it is possible to suppress the distribution of the load applied to the impact part C in the planar direction during the collision. Consequently, the load applied to the impact part C can be increased.

[0096] <Second Embodiment> The difference between the charging connector and the method for setting the drop impact value of the charging connector in this embodiment and the charging connector and the method for setting the drop impact value of the charging connector in the first embodiment is that the protective member is locally positioned on the lower part of the outer peripheral edge of the tip of the cylindrical body of the long axis cylindrical part. Here, only the difference will be explained.

[0097] Figure 14 shows a front view of the charging connector of this embodiment. The same reference numerals are used for parts corresponding to those in Figure 3. As shown by hatching in Figure 14, the protective member 51 is locally positioned on the lower portion 503D of the outer peripheral edge 503 at the tip of the cylindrical body 50 of the long-axis cylindrical portion 5. Furthermore, the protective member 51 is locally positioned on the lower portion 504D of the tip surface 504 corresponding to the lower portion 503D. Here, "lower portion 503D, 504D" refers to the portion below the center of gravity G5 of the outer peripheral edge 503 (more specifically, the elongated oval shape formed by the outer peripheral edge 503, which is long in the left-right direction) when viewing the tip of the cylindrical body 50 from the front-rear direction (axial direction of the cylindrical body 50). Note that no protective member is positioned on the upper portion of the long-axis cylindrical portion 5 or the short-axis cylindrical portion 4.

[0098] The charging connector 1 and the method for setting the drop impact value of the charging connector in this embodiment and the charging connector and the method for setting the drop impact value of the charging connector in the first embodiment have similar effects with respect to the parts that share a common configuration. In particular, the charging connector 1 of this embodiment can suppress damage to the charging connector 1 when it is dropped upright (without being inverted). In addition, the amount of protective member 51 used can be reduced.

[0099] <Third Embodiment> The difference between the charging connector and the method for setting the drop impact value of the charging connector in this embodiment and the charging connector and the method for setting the drop impact value of the charging connector in the first embodiment is that, in contrast to the second embodiment, the protective member is locally positioned on the upper part of the outer peripheral edge of the tip of the cylindrical body of the short-axis cylindrical part. Here, only the differences will be explained.

[0100] Figure 15 shows a front view of the charging connector of this embodiment. The same reference numerals are used for parts corresponding to those in Figure 3. As shown by hatching in Figure 15, the protective member 41 is locally positioned on the upper portion 403U of the outer peripheral edge 403 at the tip of the cylindrical body 40 of the short-axis cylindrical portion 4. Furthermore, the protective member 41 is locally positioned on the upper portion 404U of the tip surface 404 corresponding to the upper portion 403U. Here, "upper portion 403U, 404U" refers to the portion above the center of gravity G4 of the outer peripheral edge 403 (more specifically, the partially circular shape formed by the outer peripheral edge 403 with a missing upper end) when viewing the tip of the cylindrical body 40 from the front-rear direction (axial direction of the cylindrical body 40). Note that no protective member is positioned on the lower portion of the short-axis cylindrical portion 4 or the long-axis cylindrical portion 5.

[0101] The charging connector 1 and the method for setting the drop impact value of the charging connector in this embodiment and the charging connector and the method for setting the drop impact value of the charging connector in the first embodiment have similar effects with respect to the parts that share a common configuration. In particular, the charging connector 1 of this embodiment can suppress damage to the charging connector 1 when it is dropped upside down. In addition, the amount of protective member 41 used can be reduced. The pair of impact parts C of the upper part 403U are set in the drop posture setting step S21 shown in Figure 5 when the second posture is tilted in the opposite direction (forward) to the tilting direction (rearward) shown in Figure 9.

[0102] <Other> The embodiments of the charging connector and the method for setting the drop impact value of the charging connector described herein have been explained above. However, the embodiments are not particularly limited to the above forms. Various modified and improved forms can be implemented by those skilled in the art.

[0103] The material of the elastomer forming the protective members 41 and 51 is not particularly limited. It can be a different material from the resin forming the cylindrical body 40 and 50, and can be an elastic material whose main component is an organic material (such as a thermosetting elastomer, photocurable elastomer, thermoplastic elastomer, or rubber).

[0104] The type of resin used to form the cylindrical bodies 40 and 50 is not particularly limited. PA, PBT, PPS, LCP, PC, ABS, etc., may be used. PA66-GF and PA66-CF (carbon fiber) are commonly used as fiber-reinforced resins. The fiber length, fiber diameter, blending ratio, and orientation of the fibers blended into the fiber-reinforced resin are not particularly limited. The shape and number of cylindrical bodies 40 and 50 are not particularly limited. For example, the number of cylindrical bodies 40 and 50 may be single. It is sufficient that it conforms to the charging specifications of the charging connector 1 described later.

[0105] The standard specifying the Charpy impact value used in step S1 for obtaining the fracture strength threshold shown in Figure 5 is not particularly limited. It may be a national standard such as JIS, ANSI, GB / T, AS, DIN, or an international standard such as ISO.

[0106] The charging standard for charging connector 1 is not particularly limited. It may be CHAdeMO®, TYPE1-SAEJ1772, TYPE2-IEC62196-2, CCS1, CCS2, TESLA, GB / T20234.2, GB / T20234.3, etc. The charging method may be normal charging, fast charging, etc.

[0107] The method for obtaining the fracture strength threshold σth is not particularly limited. The fracture strength threshold σth may be obtained using the Charpy impact value. The fracture strength threshold σth may also be obtained using empirical rules or the like. In the design of multiple charging connectors 1 that share a common standard, a common fracture strength threshold σth may be used. In this case, the fracture strength threshold acquisition step S1 shown in Figure 5 can be omitted. The impact mitigation characteristics of the protective members 41 and 51, which are adjusted in the impact mitigation characteristic adjustment step S4 shown in Figure 5, are not particularly limited. They may include wall thickness, elastomer material, layer structure, shape, etc.

[0108] In the method for setting the drop impact value of the charging connector 1 in the first embodiment, an analysis model 1 without protective members 41 and 51 was used, as shown in Figure 7. However, the configuration of the analysis model 1 is not particularly limited. An analysis model 1 having at least one of the protective members 41 and 51 may also be used. For example, an analysis model 1 having protective members 41 and 51 may be used, similar to the charging connector 1 shown in Figure 2. Then, the impact mitigation characteristics of the protective members 41 and 51 (such as the thickness of the protective members 41 and 51) should be adjusted according to the analysis method shown in Figure 5.

[0109] The method for integrating the protective member 41 with the cylindrical body 40 is not particularly limited. Insert molding may be used. Alternatively, the protective member 41 may be laminated and bonded to the cylindrical body 40. The same applies to the protective member 51.

[0110] The connector body 2 and the connecting part 3 may be a single unit or a composite unit made up of multiple components. Multiple connecting parts 3 may be interchangeably connected to a single connector body 2. Also, multiple short-axis cylindrical parts 4 and multiple long-axis cylindrical parts 5 may be interchangeably connected to a single connector body 2. The material of the housing 20 and grip part 200 of the connector body 2 is not particularly limited. It may be made of resin, metal, or the like.

[0111] Making the connecting portion 3, the short shaft portion 4, and the long shaft portion 5 replaceable allows for the replacement of components including the damaged part, depending on the specific damaged area. For example, if the tip portion 502 of the long shaft portion 5 is damaged, only the long shaft portion 5 or only the connecting portion 3 can be replaced locally. This reduces replacement costs compared to replacing the entire charging connector 1.

[0112] The type of chamfered portion 501 shown in Figure 4 is not particularly limited. It may be a C-chamfered portion, an R-chamfered portion, etc. The chamfered portion 501 may be placed only on the outer peripheral edge 503 of the cylindrical body 50 where the protective member 51 is placed. It is also not necessary to place the chamfered portion 501 on the outer peripheral edge 503. The same applies to the chamfered portion of the cylindrical body 40.

[0113] The drop height H shown in Figure 12 is not particularly limited. If the drop height H is increased (for example, drop height H = 2m), the drop impact value σ1 will increase. For this reason, conditions can be deliberately set that make the charging connector 1 more susceptible to damage, and the impact mitigation characteristics of the protective members 41 and 51 can be adjusted. Therefore, damage to the charging connector 1 can be suppressed more reliably.

[0114] In step S20 of creating the analysis model shown in Figure 5, the mass of the analysis model 1 may be set to the maximum mass among multiple charging connectors 1 corresponding to the same charging connector 1 standard. Doing so increases the drop impact value σ1, making the analysis model 1, i.e., the charging connector 1, more susceptible to damage. By setting the mass of the analysis model 1 to the maximum mass among multiple charging connectors 1 of the same standard in this way, it is possible to deliberately set conditions that make the charging connector 1 more susceptible to damage and adjust the impact mitigation characteristics of the protective members 41 and 51. Therefore, damage to the charging connector 1 can be suppressed more reliably.

[0115] The fracture strength threshold acquisition step S1 and the drop impact value acquisition step S2 shown in Figure 5 are independent of each other. Therefore, there are no particular restrictions on the order in which the two steps are performed. Either the fracture strength threshold acquisition step S1 is performed first, or the drop impact value acquisition step S2 is performed first. Of course, both steps may be performed in parallel.

[0116] The method for setting the drop impact value of the charging connector 1 shown in Figure 5 can be used not for the design of the charging connector 1, but as a method for evaluating the impact resistance of an existing charging connector 1. Below, the method for evaluating the impact resistance of a charging connector (hereinafter abbreviated as "impact resistance evaluation method") will be briefly explained. Note that the impact resistance evaluation method described below can be performed independently of the charging connector and the method for setting the drop impact value of the charging connector described above.

[0117] The impact resistance evaluation method has a part of the configuration of (9) described above. That is, the impact resistance evaluation method is an impact resistance evaluation method for a charging connector having a connecting cylindrical portion that is detachably connected to the device-side connector of a device to be charged, wherein the connecting cylindrical portion has a cylindrical body, and the method is characterized by having a fracture strength threshold acquisition step in which the maximum value of the von Mises stress generated in a test piece is obtained when a Charpy impact test is simulated to cause impact fracture using FEM analysis and the maximum value is set as the fracture strength threshold, a drop impact value acquisition step in which the von Mises stress generated in the impact part is obtained when the analysis model of the charging connector is simulated to be dropped using FEM analysis and the von Mises stress is set as the drop impact value, and a comparison step in which the fracture strength threshold and the drop impact value are compared.

[0118] The impact resistance evaluation method for the charging connector 1 includes a step S1 for obtaining a fracture strength threshold, a step S2 for obtaining a drop impact value, and a comparison step S3, as shown in Figure 5. According to this impact resistance evaluation method, for example, the impact resistance of an existing charging connector 1 can be re-examined to conform to the "iron ball drop test" of IEC 62196-1 "Plugs, outlets, vehicle couplers and vehicle inlets - Conductive charging for electric vehicles - Part 1: General requirements". The material of the housing 20 and cylindrical body 40, 50 of the charging connector 1 to be inspected is not particularly limited. It may be made of resin, metal, or the like.

[0119] Furthermore, for charging connectors 1 that fail the comparison step S3 (drop impact value σ > fracture strength threshold σth), the impact mitigation characteristic adjustment step S4 shown in Figure 5 is performed, and a protective member 51 (see Figure 4) of a predetermined thickness is placed on the impact part C (in other words, by converting an existing charging connector into the charging connector of this disclosure), thereby improving the impact resistance of the charging connector. Thus, the charging connector of this disclosure may be manufactured by reusing an existing charging connector.

[0120] 1: Charging connector (analysis model), 2: Connector body, 20: Housing, 200: Grip part, 3: Connection part, 4: Short shaft cylinder part, 40: Cylinder body, 400: Pin, 402: Tip part, 403: Outer edge, 403U: Upper part, 404: Tip surface, 404U: Upper part, 41: Protective member, 411: Chamfered part, 413: Outer edge, 5: Long shaft cylinder part, 50: Cylinder body, 500: Pin, 501: Chamfered part, 502: Tip part, 503: Outer edge, 503a: Rear edge, 503b: Part, 503D: Lower part, 504: Tip surface, 504D: Lower part, 505: Outer surface, 51: Protective member, 511: Chamfered part, 513: Outer edge, 514: Tip surface, 515: Outer surface, 90: Charging cable θ: drop angle, σ1: drop impact value, σ2: drop impact value, σth: fracture strength threshold, C: impact point, E: drop surface, G: center of gravity, H: drop height, L: impact line, S1: fracture strength threshold acquisition step, S2: drop impact value acquisition step, S20: analysis model creation step, S21: drop posture setting step, S22: calculation step, S3: comparison step, S4: impact mitigation characteristic adjustment step

Claims

1. A charging connector comprising a connecting portion having a connecting cylindrical portion that can be connected to and disconnected from the device-side connector of a device to be charged, wherein the connecting cylindrical portion comprises a resin cylindrical body and an elastomer protective member that covers at least a part of the tip of the cylindrical body, the protective member is positioned at the impact portion that strikes the surface when the charging connector is dropped, the drop impact value is defined as the von Mises stress generated at the impact portion when it is dropped, and the fracture strength threshold is defined as the maximum value of the von Mises stress generated in a test piece when a load corresponding to the Charpy impact value specified in a predetermined standard for the resin is applied to the test piece according to the standard, and the drop impact value is set to be less than or equal to the fracture strength threshold.

2. The charging connector according to claim 1, wherein the standard specifying the Charpy impact value is JIS K 7111.

3. The charging connector according to claim 1, wherein the thickness of the protective member is 3 mm or more.

4. The charging connector according to claim 1, wherein the hardness of the elastomer is 50 degrees or more and 90 degrees or less.

5. The charging connector according to claim 1, comprising a connector body and a plurality of connecting cylindrical portions corresponding to the same charging connector standard, wherein the plurality of connecting cylindrical portions are interchangeably connected to the connector body.

6. The charging connector according to claim 1, wherein a chamfered portion covered by the protective member is provided at the corner of the tip of the cylindrical body.

7. The charging connector according to claim 1, wherein the charging connector conforms to the CCS2 standard, the connecting portion comprises a short-axis cylindrical portion and a long-axis cylindrical portion having a longer axial length than the short-axis cylindrical portion, the short-axis cylindrical portion is positioned above the long-axis cylindrical portion during use, and the protective member is positioned on at least a portion of the upper part of the outer peripheral edge of the tip of the cylindrical body of the short-axis cylindrical portion.

8. The charging connector according to claim 1, wherein the charging connector conforms to the CCS2 standard, the connecting portion comprises a short-axis cylindrical portion and a long-axis cylindrical portion having a longer axial length than the short-axis cylindrical portion, the long-axis cylindrical portion being positioned below the short-axis cylindrical portion during use, and the protective member being positioned on at least a portion of the lower outer edge of the tip of the cylindrical portion body of the long-axis cylindrical portion.

9. A method for setting the drop impact value of a charging connector having a connecting portion having a connecting cylindrical portion that can be connected to and detached from the device-side connector of a device to be charged, wherein the connecting cylindrical portion comprises a resin cylindrical body and an elastomer protective member that covers at least a part of the tip of the cylindrical body, the protective member is positioned at the impact portion that collides with the falling surface when the charging connector is dropped, the method comprising: a step of obtaining a fracture strength threshold when a Charpy impact test is simulated using FEM analysis to cause impact fracture and the maximum value of the von Mises stress generated in the test piece is obtained, and the maximum value is set as the fracture strength threshold; a step of obtaining a drop impact value when an analysis model of the charging connector is simulated to be dropped using FEM analysis and the von Mises stress generated at the impact portion is obtained, and the von Mises stress is set as the drop impact value; a comparison step of comparing the fracture strength threshold and the drop impact value; and an impact mitigation characteristic adjustment step of adjusting the impact mitigation characteristics of the protective member so that the drop impact value becomes less than or equal to the fracture strength threshold if the drop impact value exceeds the fracture strength threshold. A method for setting the drop impact value of a charging connector, characterized by having the following features.

10. A method for setting the drop impact value of a charging connector according to claim 9, wherein the drop posture of the analysis model is set in the drop impact value acquisition step such that the drop angle approaches 90° and the area of ​​the collision part is reduced, with the line connecting the center of gravity of the analysis model and the collision part being defined as the collision line, and the angle of intersection between the falling surface and the collision line being defined as the drop angle.

11. A method for setting the drop impact value of a charging connector according to claim 9, wherein in the step of obtaining the fracture strength threshold, a load corresponding to the Charpy impact value specified in a predetermined standard for the resin is applied to the test piece.

12. The method for setting the drop impact value of a charging connector according to claim 11, wherein the standard specifying the Charpy impact value is JIS K 7111.

13. The method for setting the drop impact value of a charging connector according to claim 9, wherein the impact mitigation characteristic is the thickness of the protective member.

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