Test equipment and impact test methods

Abstract

The present invention provides a test facility for conducting impact tests on automotive parts, which can be used to evaluate the internal structure or contents of automotive parts. [Solution] The test equipment (10) is used to perform impact tests on automobile parts (20). The test equipment (10) comprises a receiving body (11) and a holder (12) for holding the automobile parts (20). The receiving body (11) includes an impact absorbing member (113). The holder (12) is configured to move toward the receiving body (11) and collide with the receiving body (11). The holder (12) is configured to protect at least the portion of the automobile parts (20) located toward the receiving body (11) from collision with the receiving body (11).

Description

Technical Field

[0001] The present disclosure relates to test equipment, and more particularly to test equipment for performing impact tests on automotive parts. The present disclosure also relates to a method for performing an impact test on automotive parts using this test equipment.

Background Art

[0002] As a device for performing an impact test, for example, a drop test device as disclosed in Patent Document 1 is known. The drop test device of Patent Document 1 drops a test object such as a portable product onto a collision receiving base. More specifically, the drop test device of Patent Document 1 drops the test object while holding it in a test object holding portion, and releases the holding of the test object by the test object holding portion before the test object collides with the collision surface of the collision receiving base, and drops the test object alone. Patent Document 1 describes that thereby, the free fall time of the test object can be shortened, and the test object can be made to collide with the collision surface in a set posture and in a free fall state or a state close thereto, and a drop test with good reproducibility can be performed.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In an impact test of automotive parts, acceleration is applied to the automotive parts as test objects, assuming a collision of the vehicle, driving on a rough road, or sudden braking of the vehicle. Among automotive parts, there are some, for example, battery cases, for which evaluation of destruction or damage of their internal structure or contents is required. In such a collision test of automotive parts, it is necessary to apply acceleration to the automotive parts while maintaining the outer shape of the automotive parts.

[0005] The object of this disclosure is to provide a test equipment for performing impact tests on automotive parts, which can evaluate the internal structure or contents of automotive parts. [Means for solving the problem]

[0006] The test equipment relating to this disclosure is used for impact testing of automotive parts. The test equipment comprises a receiving body and a holder for holding the automotive parts. The receiving body includes an impact absorbing member. The holder is configured to move toward the receiving body and collide with the receiving body. The holder is configured to protect at least the portion of the automotive part located toward the receiving body from collision with the receiving body. [Effects of the Invention]

[0007] The test equipment described herein can be used for impact testing of automotive parts and can be used to evaluate the internal structure or contents of automotive parts. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is a perspective view showing the schematic configuration of the test equipment according to this embodiment. [Figure 2] Figure 2 is a perspective view of the test equipment with the holder removed. [Figure 3] Figure 3 is a front view of the holder. [Figure 4] Figure 4 is a perspective view of the holder from the back. [Figure 5] Figure 5 is a perspective view of the test equipment from the rear. [Figure 6A] Figure 6A is a side view showing an example of a pipe that can be used in the test facility. [Figure 6B] Figure 6B is a cross-sectional view (VIB-VIB section) of the pipe shown in Figure 6A. [Figure 6C] Figure 6C is a cross-sectional view (VIC-VIC section) of the pipe shown in Figure 6A. [Figure 7A]Figure 7A is a side view showing another example of a pipe that can be used in the test facility. [Figure 7B] Figure 7B is a cross-sectional view (VIIB-VIIB section) of the pipe shown in Figure 7A. [Figure 7C] Figure 7C is a cross-sectional view (VIIC-VIIC section) of the pipe shown in Figure 7A. [Figure 8A] Figure 8A is a schematic diagram illustrating the impact test method according to the embodiment. [Figure 8B] Figure 8B is a schematic diagram illustrating the impact test method according to the embodiment. [Figure 9] Figure 9 is a graph showing an example of the acceleration of automotive parts measured in impact tests. [Figure 10] Figure 10 is a front view showing a schematic configuration of a test facility according to a modified embodiment. [Modes for carrying out the invention]

[0009] The test apparatus according to the embodiment is used to perform impact tests on automotive parts. The test apparatus comprises a receiving body and a holder for holding the automotive parts. The receiving body includes an impact absorbing member. The holder is configured to move toward the receiving body and collide with the receiving body. The holder is configured to protect at least the portion of the automotive part located toward the receiving body from collision with the receiving body (first configuration).

[0010] In an impact test of an automobile part using the test equipment relating to the first configuration, a holder that holds the automobile part collides with a receiving body that includes an impact absorbing member. The holder can protect at least the portion of the automobile part located on the receiving body side from collision with the receiving body. In other words, the automobile part does not directly collide with the receiving body. Therefore, even when acceleration is applied to the holder and the automobile part due to the collision between the receiving body and the holder, the external shape of the automobile part is more likely to be maintained. Consequently, it is possible to evaluate the internal structure or contents of the automobile part for destruction or damage.

[0011] In the test equipment according to the first configuration, the holder may include a frame. The frame can surround the automotive part in a plan view of the automotive part (second configuration).

[0012] According to the second configuration, the automotive part can be surrounded by the frame of the holder in its plan view. In this case, when the holder holding the automotive part moves and when it collides with the receptor, the outer shape of the automotive part is more likely to be maintained. Therefore, for example, even when the size of the automotive part is large, it becomes easy to perform an impact test on the automotive part, and it is possible to evaluate the internal structure or contents of the automotive part for destruction or damage.

[0013] In the test equipment according to the first or second configuration, the automotive part may have dimensions of 300 mm × 300 mm or more and 3000 mm × 3000 mm or less in a plan view (third configuration).

[0014] In the test equipment according to any one of the first to third configurations, the shock absorption member may be at least one pipe. The pipe extends, for example, in the moving direction of the holder (fourth configuration).

[0015] In the fourth configuration, the shock absorption member is at least one pipe. The pipe extends in the moving direction of the holder and absorbs the shock at the time of the collision of the holder. In this case, it becomes easy to adjust the acceleration generated in the automotive part due to the direct or indirect collision between the holder and the shock absorption member.

[0016] In the test equipment according to the fourth configuration, the pipe can include beads having a predetermined pitch in the axial direction. The beads may have both ends in the circumferential direction of the pipe in a cross-sectional view of the pipe. The beads are preferably formed on the pipe such that the positions of the beads in the circumferential direction are different between the cross-sections of the pipe spaced apart in the axial direction (fifth configuration).

[0017] In the fifth configuration, a bead is formed on the pipe, which serves as the shock-absorbing member. This bead has a predetermined pitch in the axial direction and has both ends in the circumferential direction of the pipe when viewed in cross-section. In addition, when comparing the cross-sections of pipes spaced apart in the axial direction, the position of the bead in the circumferential direction of the pipe differs between the two cross-sections. This makes it less likely for the acceleration generated in the holder and the automobile part to fluctuate when the holder holding the automobile part collides with the receiving body, which includes the pipe as the shock-absorbing member. Specifically, the bead formed on the pipe can serve as the starting point for deformation when an axial compressive load is applied to the pipe due to the collision between the holder and the receiving body, causing the pipe to plastically deform (collapse). In the fifth configuration, since the position of the bead in the circumferential direction of the pipe changes along the axial direction of the pipe, when the pipe collapses, the position where deformation occurs in the circumferential direction of the pipe also changes along the axial direction of the pipe. As a result, the deformation of the pipe is made uniform, and uniform stress is more likely to be generated in the pipe. Consequently, fluctuations in the load generated on the pipe, in other words, the load generated on the holder and the automobile part, are suppressed, and fluctuations in the acceleration applied to the automobile part are also suppressed.

[0018] In the test equipment relating to the fifth configuration, the pipes may be made of metal (sixth configuration).

[0019] In the test equipment relating to the sixth configuration, the pipe may have a Vickers hardness of 80 HV or higher (seventh configuration).

[0020] In a test facility relating to any of the first to seventh configurations, the impact absorbing member may be configured to maintain the acceleration generated in the holder when the holder holding the automobile part collides with the receiving body at a rate of at least 0.5 times the maximum acceleration of the holder and at least 1 / 8 milliseconds less than or equal to the maximum acceleration (eighth configuration).

[0021] In a test facility relating to any of the first to fifth and eighth configurations, the shock-absorbing member may be made of resin (ninth configuration).

[0022] The impact test method according to the embodiment is an impact test method for automobile parts using a test facility according to any of the configurations 1 to 9. The impact test method comprises the steps of holding the automobile part to be tested in a holder and colliding the holder holding the automobile part with a receiving body (configuration 10).

[0023] Embodiments of this disclosure will be described below with reference to the drawings. In these drawings, the same or equivalent components are denoted by the same reference numerals, and the same description will not be repeated.

[0024] [Testing Equipment] Figure 1 is a perspective view showing the schematic configuration of the test equipment 10 according to this embodiment. The test equipment 10 is used to perform impact tests on automotive parts 20. Automotive parts 20 are, for example, battery cases used in electric vehicles (BEVs) and the like. Automotive parts 20 may also be battery modules or battery cells housed within the battery case.

[0025] The test equipment 10 comprises a receiving body 11 and a holder 12. The holder 12 can hold the automobile part 20. The holder 12 is configured to move toward the receiving body 11 and collide with the receiving body 11. The test equipment 10 may further comprise a support plate 13 and guides 14, 15.

[0026] The support body 11 is provided in the test equipment 10 to receive the holder 12. In this embodiment, the support body 11 is positioned below the holder 12. The support body 11 includes an upper plate 111, a lower plate 112, and a shock-absorbing member 113.

[0027] The upper plate 111 is positioned on the holder 12 side relative to the lower plate 112. Of the two surfaces of the upper plate 111 in the thickness direction, one surface is positioned on the holder 12 side, and the other surface faces the surface of the lower plate 112 with a gap between them. In this embodiment, the upper plate 111 is positioned above the lower plate 112. The lower plate 112 may be supported from below by the legs 114.

[0028] In this embodiment, the shock-absorbing member 113 is positioned between the upper plate 111 and the lower plate 112. The shock-absorbing member 113 may be at least one pipe 113a. In this embodiment, the shock-absorbing member 113 is a plurality of pipes 113a. In this case, these pipes 113a may have the same shape or may have different shapes. The pipes 113a extend between the upper plate 111 and the lower plate 112.

[0029] Each pipe 113a may be supported by a shaft member 115. That is, the shaft members 115 may be positioned within the pipes 113a. The shaft members 115 extend between the upper plate 111 and the lower plate 112. One end (upper end) of the shaft member 115 is fixed to the upper plate 111 by a fastening member 116, for example, a bolt. The other end (lower end) of the shaft member 115 does not have to be fixed to the lower plate 112. For example, a through hole through which the shaft member 115 can be inserted may be formed in the lower plate 112. As the shaft member 115 moves axially within this through hole, the upper plate 111 to which the shaft member 115 is fixed can move closer to or further away from the lower plate 112.

[0030] The pipe 113a and the shaft member 115 are detachable from the support body 11. Since the shaft member 115 is not fixed to the lower plate 112, the upper plate 111 and the shaft member 115 can be easily separated from the lower plate 112, allowing the pipe 113a that was installed in the support body 11 to be removed, or a new pipe 113a to be installed in the support body 11. Furthermore, if the shaft member 115 is fixed to the upper plate 111 by a fastening member 116, the fastening member 116 can be loosened to remove the shaft member 115 from the upper plate 111, or a new shaft member 115 can be fastened to the upper plate 111 using the fastening member 116.

[0031] When the test equipment 10 is in use, the required number of pipes 113a can be installed on the support body 11. When the test equipment 10 is in use, each pipe 113a is positioned between the upper plate 111 and the lower plate 112 with the shaft member 115 inserted. The number of pipes 113a installed in the test equipment 10 does not have to match the number of shaft members 115. That is, as shown in Figure 1, there may be shaft members 115 to which no pipes 113a are attached.

[0032] The holder 12 is configured to protect at least the portion of the automobile part 20 located on the receiving body 11 side from collision with the receiving body 11. In this embodiment, the holder 12 includes a frame 121. The frame 121 has a frame shape. For example, the frame 121 has a rectangular frame shape. However, the frame 121 may have a polygonal frame shape other than a rectangle. The automobile part 20 is protected from collision with the receiving body 11 by the frame 121.

[0033] In this embodiment, the holder 12 moves guided by the guide 14. The guide 14 may be a known linear guide, such as an LM guide (registered trademark). Figure 2 is a perspective view of the test equipment 10 with the holder 12 removed. As shown in Figure 2, the guide 14 includes a rail member 141 and at least one carriage 142.

[0034] The rail member 141 is attached to the support plate 13 directly or indirectly. The rail member 141 extends in the direction of movement of the holder 12 (Figure 1). In this embodiment, the rail member 141 extends in the vertical direction (up and down direction). On the rail member 141, a convex rail 141a is formed on the surface facing the holder 12 (Figure 1). The rail 141a extends in the longitudinal direction of the rail member 141.

[0035] In this embodiment, the guide 14 includes a plurality of carriages 142. Each carriage 142 is configured to slide along the rail 141a in the longitudinal direction of the rail member 141. More specifically, the portion of the carriage 142 on the rail member 141 side has a recess formed therein that corresponds to the rail 141a. The carriage 142 can slide along the rail 141a with the rail 141a positioned within the recess. Rollers (not shown) for forming a circulating linear bearing may be provided between the carriage 142 and the rail 141a.

[0036] An arm member 143 may be connected to the rail member 141. The arm member 143 is attached, for example, to one end of the rail member 141 in the longitudinal direction. In the example in Figure 1, the arm member 143 is attached to the upper end of the rail member 141 and protrudes from the rail member 141 toward the front side of the test equipment 10. A magnet 16 is suspended from the arm member 143. The magnet 16 may have a function to switch between generating and not generating magnetic force by operating an ON / OFF switch. A known ON / OFF switchable magnet can be used as the magnet 16.

[0037] In the test equipment 10 according to this embodiment, in addition to the guide 14, a guide 15 is provided on the support plate 13. Referring to Figures 1 and 2, the guides 15 are positioned on both sides of the holder 12 in a front view of the test equipment 10 and are attached to the support plate 13. Each of the guides 15 may include a guide roller 151. Each of the guides 15 is attached to the support plate 13 so as to be able to contact the holder 12 by the guide roller 151.

[0038] Figure 3 is a front view of the holder 12 as seen from the front of the test equipment 10. Figure 4 is a perspective view of the holder 12 as seen from the rear of the test equipment 10. Figure 3 shows the holder 12 holding the automobile part 20, while Figure 4 shows the holder 12 without holding the automobile part 20.

[0039] In this embodiment, a front view of the test equipment 10 (Figure 1) is synonymous with a plan view of the automobile part 20. A plan view of the automobile part 20 means viewing the automobile part 20 along its thickness direction. For example, if the automobile part 20 is a battery case, when the automobile part 20 is held by the holder 12 in the test equipment 10, the thickness direction of the battery case coincides with the depth direction of the test equipment 10. The thickness direction of the battery case corresponds to the vertical direction of the automobile in which the battery case is used. The longitudinal direction and width direction of the battery case correspond to the front-to-back direction and left-to-right direction of the automobile in which the battery case is used, respectively.

[0040] Referring to Figure 3, the frame 121 of the holder 12 is configured to surround the automobile part 20 in a plan view of the automobile part 20. If the automobile part 20 is a battery case, the frame 121 may be configured so that its inner circumferential surface faces the side wall of the battery case. When the holder 12 holds the automobile part 20, the inner circumferential surface of the frame 121 may be in contact with the automobile part 20, or a gap may be formed between the inner circumferential surface of the frame 121 and the automobile part 20.

[0041] The automobile part 20 may have dimensions of 300 mm × 300 mm or more and 3000 mm × 3000 mm or less in its plan view. In other words, when the automobile part 20 is orthographically projected onto a plane perpendicular to the thickness direction, it may have a projected area A of 300 mm × 300 mm or more and 3000 mm × 3000 mm or less. The inner dimensions of the frame 121 of the holder 12 may be slightly larger than the dimensions of the automobile part 20. That is, when the frame 121 of the holder 12 is orthographically projected onto a plane perpendicular to the thickness direction of the automobile part 20, the inner area of ​​the frame 121 on the projected plane may be 300 mm × 300 mm or more and 3000 mm × 3000 mm or less, but may slightly exceed 3000 mm × 3000 mm.

[0042] The frame 121 is made of, for example, metal. The frame 121 may be made of steel. From the viewpoint of protecting the automobile parts 20, it is preferable that the frame 121 has a sufficient thickness T. The thickness T is the dimension from the inner circumferential surface to the outer circumferential surface of the frame 121. The thickness T is, for example, 2.0 mm or more, preferably 9.0 mm or more. The thickness T may be, for example, 50.0 mm or less, preferably 30.0 mm or less. The thickness T is measured, for example, in the portion of the frame 121 that is located on the receiving body 11 (Figure 1) side.

[0043] Referring to Figure 4, the holder 12 may include beam members 122 in addition to the frame 121. The beam members 122 are attached to the frame 121 on the rear side of the test equipment 10 (Figure 1). The beam members 122 may have, for example, a cross shape. As shown in Figure 4, the beam members 122 may include a plurality of vertical beam sections 122a and a plurality of horizontal beam sections 122b. Each vertical beam section 122a extends in the direction of movement of the holder 12 and is connected to the frame 121. Each horizontal beam section 122b extends in a direction intersecting the direction of movement of the holder 12 and is connected to the frame 121. In this embodiment, each of the vertical beam sections 122a extends vertically (up and down), and each of the horizontal beam sections 122b extends horizontally (left and right).

[0044] The beam member 122 is provided with at least one mounting portion 123. The mounting portion 123 may, for example, be plate-shaped. In this embodiment, the beam member 122 is provided with a plurality of mounting portions 123. More specifically, the vertical beam portion 122a and the horizontal beam portion 122b are each provided with a mounting portion 123.

[0045] Figure 5 is a perspective view of the test equipment 10 as seen from the rear. In Figure 5, the support plate 13 and the automobile part 20 (Figure 1) are omitted. Referring to Figure 5, the holder 12 is attached to the guide 14 at the mounting portion 123. Specifically, the holder 12 is attached to the guide 14 by fastening the mounting portion 123 to each of the carriages 142. In this embodiment, the mounting portion 123 provided on the vertical beam portion 122a is fastened to the carriage 142.

[0046] As described above, in the test equipment 10 according to this embodiment, at least one pipe 113a is used as the shock-absorbing member 113. Figures 6A to 6C show examples of usable pipes 113a. Figure 6A is a side view of the pipe 113a, and Figures 6B and 6C are cross-sectional views of the pipe 113a. The cross-section of the pipe 113a refers to the cross-section perpendicular to the axial direction of the pipe 113a.

[0047] Referring to Figure 6A, the pipe 113a includes a bead 113b having a predetermined pitch P in the axial direction. The pitch P of the bead 113b may be constant or non-constant over the entire length of the pipe 113a in the axial direction. In the example of Figure 6A, the bead 113b includes a plurality of beads 113c and a plurality of beads 113d. Each of the beads 113c and 113d extends in the circumferential direction of the pipe 113a. However, each of the beads 113c and 113d may extend non-parallel to the circumferential direction of the pipe 113a. In the example of Figure 6A, the beads 113c and 113d have a shape that is convex inward of the pipe 113a. However, the beads 113c and 113d may have a shape that is convex outward of the pipe 113a.

[0048] The beads 113c are arranged with a pitch P in the axial direction of the pipe 113a. The beads 113d are also arranged with a pitch P in the axial direction of the pipe 113a. The beads 113d are positioned offset from the beads 113c in the axial and circumferential directions of the pipe 113a. In this embodiment, one row of beads 113c and one row of beads 113d are formed on the pipe 113a. However, multiple rows of beads 113c and multiple rows of beads 113d may be formed on the pipe 113a. Two or more types of bead rows with different positions in the axial and circumferential directions may be formed on the pipe 113a.

[0049] Figure 6B is a cross-sectional view of pipe 113a when cut along the VIB-VIB line in Figure 6A. The cross-section of pipe 113a shown in Figure 6B includes at least one bead 113c. The cross-section of pipe 113a may include multiple beads 113c.

[0050] As shown in Figure 6B, in the cross-section of pipe 113a, the bead 113c has both ends in the circumferential direction of pipe 113a. That is, the bead 113c does not extend around the entire circumference of pipe 113a. In the cross-section of pipe 113a, there are parts where the bead 113c is not present, i.e., there are gaps in the bead 113c.

[0051] Figure 6C is a cross-sectional view of pipe 113a (VIC-VIC section of Figure 6A) taken at a position axially separated from Figure 6B. More specifically, Figure 6C is a cross-sectional view of pipe 113a at a position axially separated from the cross-section shown in Figure 6B by half the pitch P of the beads 113c and 113d. The cross-section of pipe 113a shown in Figure 6C includes at least one bead 113d. The cross-section of pipe 113a may include multiple beads 113d.

[0052] As shown in Figure 6C, in the cross-section of pipe 113a, the bead 113d has both ends in the circumferential direction of pipe 113a. That is, the bead 113d does not extend around the entire circumference of pipe 113a. In the cross-section of pipe 113a, there are parts where the bead 113d is not present, i.e., there are gaps in the bead 113d.

[0053] The bead 113b is formed on the pipe 113a such that its position is offset in the circumferential direction between cross-sections of pipes 113a that are spaced apart in the axial direction. In the pipe 113a shown in Figures 6A and 6C, the position of the bead 113c included in the cross-section shown in Figure 6B and the bead 113d included in the cross-section shown in Figure 6C are different in the circumferential direction of the pipe 113a. In Figure 6B and the example in Figure 6B, the bead 113c is positioned 180° offset from the bead 113d around the central axis C of the pipe 113a.

[0054] Figures 7A to 7C show another example of a usable pipe 113a. Figure 7A is a side view of the pipe 113a, and Figures 7B and 7C are cross-sectional views of the pipe 113a. In the example shown in Figures 7A to 7C, the bead 113b has a helical shape. In this case as well, the pitch P of the bead 113b may be constant or non-constant over the entire axial length of the pipe 113a. The bead 113b may have a convex shape on the inside of the pipe 113a, or a convex shape on the outside of the pipe 113a.

[0055] Figures 7B and 7C are cross-sectional views of pipe 113a taken at positions separated in the axial direction (VIIB-VIIB and VIIC-VIIC sections in Figure 7A). Figures 7B and 7C show cross-sections of pipe 113a separated axially by half the pitch P of the bead 113b. As shown in Figures 7A and 7B, even when the bead 113b is helical, the bead 113b has both ends in the circumferential direction of pipe 113a in the cross-section of pipe 113a. That is, in a cross-sectional view of pipe 113a, the bead 113b does not extend around the entire circumference of pipe 113a. There are parts in the cross-section of pipe 113a where the bead 113b is not present, i.e., there are gaps in the bead 113b. Also, the position of the bead 113b in the circumferential direction of pipe 113a differs between cross-sections of pipe 113a separated in the axial direction.

[0056] The pipe 113a is made of, for example, metal. The pipe 113a may be made of steel. The pipe 113a may have a Vickers hardness of 80 HV or more. The Vickers hardness of the pipe 113a may be 85 HV or more, or 90 HV or more. The Vickers hardness of the pipe 113a is, for example, 600 HV or less. The Vickers hardness of the pipe 113a can be measured as follows. First, a test piece for the Vickers hardness test is cut out from the pipe 113a. The test piece can be cut out, for example, from the part of the pipe 113a excluding the bead 113b. Then, using this test piece, a Vickers hardness test is performed on the cross-section of the pipe 113a in accordance with JIS Z 2244:2024. More specifically, the Vickers hardness is measured in the cross-section at the center or near the center in the thickness direction, and at a position 1 / 4 of the plate thickness away from each of the inner and outer surfaces, with a test force of 25 gf (0.25 N). The average of the obtained Vickers hardness values ​​is the Vickers hardness of pipe 113a.

[0057] [Impact Testing Method] Next, the impact test method using the test equipment 10 will be described with reference to Figures 8A and 8B. The impact test method according to this embodiment comprises a preparation step and a test step.

[0058] (preparation process) Referring to Figure 8A, the preparation step involves preparing the automotive part 20 to be tested and holding it in the holder 12 of the test equipment 10. If the automotive part 20 is a battery case, the automotive part 20 may be prepared with its contents, such as a battery module or battery cells, removed. In this case, a substitute with a weight equivalent to that of the contents, such as a battery module or battery cells, may be placed inside the automotive part 20.

[0059] If the holder 12 includes a frame 121, the automobile part 20 is placed within the frame 121. The automobile part 20 may be fixed to the frame 121, for example, by mechanical joints, although this is not particularly limited. The holder 12, with the automobile part 20 in place, is attached to the guide 14. More specifically, the holder 12 is attached to the carriage 142 of the guide 14 at a mounting portion 123 on its back (Figure 5). The magnet 16 is then switched ON to generate a magnetic force, causing the holder 12 to be attracted to the magnet 16. For example, the frame 121 of the holder 12 is attracted to the magnet 16. The frame 121 may be attracted directly to the magnet 16, or it may be attracted indirectly to the magnet 16 via another component provided on the holder 12. This results in the holder 12 being suspended. The holder 12 is positioned at a predetermined height. A weight 124 for weight adjustment may be installed on the holder 12. The weight 124 is attached, for example, to the frame 121.

[0060] (Testing process) Referring to Figure 8B, the test process involves colliding the holder 12, which holds the automobile part 20, with the receiving body 11. More specifically, by switching the switch of the magnet 16 from ON to OFF, the magnetic force of the magnet 16 is lost, and the holder 12 falls from the magnet 16. The holder 12 moves toward the receiving body 11 due to its own weight and collides with the receiving body 11. Guides 14 and 15 guide the holder 12 so that it falls vertically while maintaining the desired posture.

[0061] The holder 12 collides with, for example, the upper plate 111 of the receiving body 11. This generates an impact pulse in the holder 12 and the automobile part 20. That is, acceleration is generated in the automobile part 20, which is the object of the test. The acceleration given to the automobile part 20 can be measured by a measuring device 30. The measuring device 30 may be, for example, an acceleration sensor attached to the holder 12 or the automobile part 20. Alternatively, the measuring device 30 may measure the displacement of the holder 12 or the automobile part 20 in the direction of movement (vertical direction). In this case, acceleration can be calculated from the displacement of the holder 12 or the automobile part 20. The signal from the measuring device 30 may be transmitted to a control device (not shown). The control device is, for example, a computer. The control device can store the acceleration given to the automobile part 20.

[0062] Figure 9 is a graph showing an example of the acceleration of an automobile part 20 measured during an impact test. In Figure 9, the vertical axis represents acceleration and the horizontal axis represents time, showing the change in the acceleration of the automobile part 20 during the impact test.

[0063] Referring to Figure 9, impact tests using the test equipment 10 can generate impact pulses similar to trapezoidal wave impact pulses in the automobile part 20. These impact pulses are more likely to occur when the impact absorbing member 113 of the receiving body 11 is at least one pipe 113a. The pipe 113a can absorb the impact by plastically deforming when it collides with the holder 12 and the receiving body 11. When a bead 113b is provided on the pipe 113a, the stress generated in the pipe 113a is made uniform, and the load when the pipe 113a is crushed is also made uniform to some extent. Therefore, impact pulses similar to trapezoidal wave impact pulses are particularly likely to occur in the automobile part 20.

[0064] For example, when the holder 12 holding the automobile part 20 collides with the receiving body 11, the acceleration generated in the holder 12 is maintained at or above the maximum acceleration × 0.5 and below the maximum acceleration for at least 1 / 8 milliseconds of the maximum acceleration. The acceleration may also be maintained at or above the maximum acceleration × 0.5 and below the maximum acceleration for at least 1.5 seconds. The acceleration may also be maintained at or above the maximum acceleration × 0.5 and below the maximum acceleration for at least 3.0 seconds, or even at least 5.0 seconds.

[0065] Tables 1 to 3 show the results of CAE analysis performed using commercially available software (LS-Dyna, Ansys) regarding the acceleration retention time of the automobile part 20. In this analysis, one or more pipes 113a were used as the impact absorbing member 113, and the acceleration retention time was confirmed while changing the weight of the test subject, the speed of the test subject, and the number of pipes 113a. The speed is the speed of the test subject immediately before the collision occurred. The retention time is the time during which the acceleration generated in the test subject could be maintained at or above the maximum acceleration × 0.5 and below the maximum acceleration. The pipes 113a used were those with the shapes shown in Figures 6A to 6C.

[0066] [Table 1]

[0067] [Table 2]

[0068] [Table 3]

[0069] In each table, "weight" refers to the weight of the test object, which is the combined weight of the automobile part 20 and the holder 12. Table 1 shows the holding time when the weight of the test object is varied, while other conditions are kept constant. Referring to Table 1, in all cases, the acceleration generated in the test object is held for at least 1 / 8 milliseconds between maximum acceleration × 0.5 and maximum acceleration. In this analysis example, in all cases, the acceleration generated in the test object is held for at least 5.0 milliseconds between maximum acceleration × 0.5 and maximum acceleration. In this analysis, the holding time of acceleration increased as the weight of the test object increased.

[0070] Table 2 shows the holding time when the speed of the test object is varied while other conditions are kept constant. Referring to Table 2, in all cases, the acceleration generated on the test object is held for at least 1 / 8 milliseconds between the maximum acceleration and the maximum acceleration, ranging from 0.5 to 1 / 8 milliseconds. In the example of this analysis, in all cases, the acceleration generated on the test object is held for at least 5.0 milliseconds between 0.5 to 1 / 8 milliseconds. In this analysis, the holding time of acceleration increased as the speed of the test object increased.

[0071] Table 3 shows the holding time when the number of pipes 113a is varied while keeping other conditions the same. Referring to Table 3, in all cases, the acceleration generated on the test object was held for at least 1 / 8 milliseconds between the maximum acceleration and the maximum acceleration, ranging from 0.5 to 1 / 8 milliseconds. In this analysis example, in all cases, the acceleration generated on the test object was held for at least 5.0 milliseconds between 0.5 and 1 / 8 milliseconds. In this analysis, the holding time of acceleration increased as the number of pipes 113a decreased.

[0072] Returning to Figure 8B, the test process evaluates whether the internal structure or contents of the automotive part 20 are damaged or broken by the acceleration applied to the holder 12 and the automotive part 20. If the automotive part 20 is a battery case, for example, the evaluation may focus on the damage or breakage of the ends of the cross members or bolted fastenings within the automotive part 20.

[0073] [effect] In an impact test using the test equipment 10 according to this embodiment, the holder 12 holding the automobile part 20 collides with the receiving body 11, and the impact is absorbed by the impact absorbing member 113. The holder 12 can protect at least the portion of the automobile part 20 located on the receiving body 11 side from collision with the receiving body 11. In other words, the automobile part 20 does not directly collide with the receiving body 11. Therefore, even when the automobile part 20 is accelerated by the collision between the receiving body 11 and the holder 12, the external shape of the automobile part 20 is easily maintained. Consequently, it is possible to evaluate the internal structure or contents of the automobile part 20 for destruction or damage.

[0074] In the test equipment 10 according to this embodiment, the holder 12 includes a frame 121. Since the automobile part 20 is placed inside the frame 121, the frame 121 protects the automobile part 20 from collision with the receiving body 11. Therefore, the external shape of the automobile part 20 is more easily maintained during impact testing. For this reason, even if the size of the automobile part 20 is large, for example, if the dimensions of the automobile part 20 in plan view are 300 mm x 300 mm or more and 3000 mm x 3000 mm or less, impact testing of the automobile part 20 can be easily performed.

[0075] In the test equipment 10 according to this embodiment, the impact absorbing member 113 of the receiving body 11 may be at least one pipe 113a. The pipe 113a is installed in the test equipment 10 so as to extend in the direction of movement of the holder 12. The pipe 113a can absorb the impact by, for example, plastically deforming when the holder 12 collides with the receiving body 11. More specifically, the impact caused by the collision between the holder 12 and the receiving body 11 is absorbed by the pipe 113a being crushed in the axial direction. Depending on the manner of plastic deformation, the pipe 113a can impart a desired acceleration to the holder 12 and the automobile part 20. The pipe 113a may be made of metal. The impact absorbing member 113 can maintain the acceleration generated in the holder 12 when the holder 12 holding the automobile part 20 collides with the receiving body 11 at a rate of maximum acceleration × 0.5 or more and maximum acceleration or less, for a period of maximum acceleration × 1 / 8 milliseconds or more.

[0076] In this embodiment, the pipe 113a may have beads 113b having a predetermined pitch P in the axial direction. The beads 113b are formed on the pipe 113a such that both ends are located in the circumferential direction of the pipe 113a in the cross-section of the pipe 113a, and the position of the beads 113b in the circumferential direction differs between cross-sections of pipe 113a that are separated in the axial direction. More specifically, when comparing cross-sections of pipe 113a that are separated in the axial direction within a range of 1 pitch P, the position of the beads 113b in the circumferential direction differs between the cross-sections. When such a pipe 113a is used as an impact absorbing member 113, it becomes easier to maintain the acceleration generated in the automobile part 20 at a substantially constant magnitude. More specifically, because the circumferential position of the beads 113b, which are the starting point of deformation, changes in the axial direction of the pipe 113a, when the pipe 113a is crushed, the position where deformation occurs changes in the circumferential direction along the axial direction of the pipe 113a. Therefore, uniform deformation is more likely to occur in the pipe 113a in the axial and circumferential directions, and the stress generated in the pipe 113a is also more likely to be uniform. Consequently, fluctuations in the load and acceleration generated in the holder 12 and the automobile part 20 when the pipe 113a is axially crushed are more easily suppressed. For example, by using the pipe 113a as an impact absorbing member 113, the acceleration generated in the holder 12 when the holder 12 holding the automobile part 20 collides with the receiving body 11 can be kept at or above the maximum acceleration of the holder 12 × 0.5 and below the maximum acceleration for a certain period of time or longer. The "certain period of time" is, for example, 1.5 milliseconds, but it may also be 3.0 milliseconds or 5.0 milliseconds. Therefore, even when test conditions such as trapezoidal wave impact pulses are required, the impact test of the automobile part 20 can be performed under those test conditions.

[0077] In the test equipment 10 according to this embodiment, the acceleration generated in the automobile part 20 during the impact test can be adjusted. For example, by changing the shape or size of the pipe 113a as the impact absorbing member 113, the number of pipes 113a, etc., the acceleration given to the automobile part 20 by the collision between the holder 12 and the receiving body 11 can be changed. The acceleration given to the automobile part 20 can also be changed by changing the presence or absence of the weights 124 in the holder 12, or by changing the number or weight of the weights 124. The acceleration given to the automobile part 20 also changes depending on the initial position of the holder 12, that is, the height of the holder 12 before the fall.

[0078] While embodiments relating to this disclosure have been described above, this disclosure is not limited to the embodiments described above, and various modifications are possible as long as they do not deviate from its spirit.

[0079] In the above embodiment, the direction of movement of the holder 12 coincides with the longitudinal direction of the automobile part 20, in other words, the front-to-back direction of the automobile. Therefore, in the impact test, longitudinal acceleration is applied to the automobile part 20. However, the direction of movement of the holder 12 may coincide with the width direction of the automobile part 20, in other words, the left-to-right direction of the automobile. In this case, the holder 12 may be attached to the carriage 142 of the guide 14 by the attachment part 123 of the transverse beam portion 122b instead of the longitudinal beam portion 122a of the beam member 122. This makes the width direction of the automobile part 20 held by the holder 12 the vertical direction, and when the holder 12 is dropped onto the receiving body 11 in the impact test, longitudinal acceleration can be applied to the automobile part 20. Alternatively, the direction of movement of the holder 12 may coincide with the thickness direction of the automobile part 20, in other words, the up-and-down direction of the automobile. This allows acceleration in the thickness direction to be applied to the automobile part 20 in the impact test.

[0080] In the above embodiment, the impact absorbing member 113 of the receiving body 11 is at least one pipe 113a. However, the impact absorbing member 113 does not have to be a pipe 113a. For example, the impact absorbing member 113 may be made of resin. As shown in Figure 10, the impact absorbing member 113 may be at least one resin mat 113e. The resin mat 113e may be provided in the test equipment 10 so as to face the holder 12. The resin mat 113e can absorb the impact when the holder 12 collides with the resin mat 113e. When at least one resin mat 113e is used as the impact absorbing member 113, high acceleration is likely to occur in the automobile part 20 held by the holder 12. Therefore, it becomes easier to perform impact tests at higher accelerations. When the impact absorbing member 113 is made of multiple resin mats 113e, the resin mats 113e may be stacked in the direction of movement of the holder 12. Even when the impact absorbing member 113 is made of resin, the acceleration generated in the holder 12 when the holder 12 holding the automobile part 20 collides with the receiving body 11 can be maintained at a rate of maximum acceleration × 0.5 or more and maximum acceleration or less for a period of 1 / 8 millisecond or more.

[0081] Because the weight of the automobile part 20 being tested and the holder 12 that holds the automobile part 20 are large, the energy input to the automobile part 20 and the holder 12 when the holder 12 collides with the receiving body 11 is also high. If the impact absorbing member 113 is made of resin, the thickness of the impact absorbing member 113 needs to be larger than that of a typical drop test device in order to withstand the impact of the automobile part 20 and the holder 12. The thickness of the resin impact absorbing member 113 is, for example, 10 mm or more, but preferably 20 mm or more, and more preferably 30 mm or more. As shown in Figure 10, if the impact absorbing member 113 is one or more resin mats 113e, the total thickness of the resin mats 113e may be 10 mm or more, but preferably 20 mm or more, and more preferably 30 mm or more.

[0082] In the above embodiment, the holder 12 holding the automobile part 20 is dropped toward the receiving body 11. That is, the holder 12 is moved vertically. However, the direction of movement of the holder 12 does not necessarily have to be vertical. For example, the holder 12 may move along a direction inclined with respect to the vertical. The holder 12 may also move horizontally. When the holder 12 is moved horizontally, for example, an actuator can be used to push the holder 12 instead of the magnet 16.

[0083] In the above embodiment, the retainer 12 includes a frame 121 capable of surrounding the automobile part 20. However, the retainer 12 does not necessarily have to include a frame 121. The retainer 12 only needs to be configured to protect at least the portion of the automobile part 20 located on the receiving body 11 side from collision with the receiving body 11. [Explanation of Symbols]

[0084] 10: Test equipment 11: Receiving body 12: Holding body 121: Frame 113: Impact absorbing material 113a: Pipe 113b: Bead 113c: Bead 113d: Bead 20: Automotive parts

Claims

1. A test facility for conducting impact tests on automotive parts, A receiving body including an impact absorbing member, A retainer for holding the aforementioned automobile part, wherein the retainer is configured to move toward the receiving body and collide with the receiving body, Equipped with, The retainer is configured to protect at least the portion of the automobile part located on the receiving side from collision with the receiving body. The shock-absorbing member is at least one pipe extending in the direction of movement of the holder, in the test equipment.

2. The test equipment according to claim 1, The holder includes a frame capable of surrounding the automobile part in a plan view of the automobile part, and is part of a test apparatus.

3. The test equipment according to claim 1, The aforementioned automotive part is a test equipment having dimensions of 300 mm x 300 mm or more and 3000 mm x 3000 mm or less in a plan view.

4. The test equipment according to claim 1, The pipe includes beads having a predetermined pitch in the axial direction. A test apparatus in which the bead is formed on the pipe such that, in a cross-sectional view of the pipe, both ends are located in the circumferential direction of the pipe, and the position of the bead in the circumferential direction differs between cross-sections of the pipe that are spaced apart in the axial direction.

5. The test equipment according to claim 4, The aforementioned pipe is a test apparatus made of metal.

6. The test equipment according to claim 5, The aforementioned pipe is a test apparatus having a Vickers hardness of 80 HV or higher.

7. Test equipment for performing impact tests on automobile parts, A receiving body including an impact absorbing member, A retainer for holding the aforementioned automobile part, wherein the retainer is configured to move toward the receiving body and collide with the receiving body, Equipped with, The retainer is configured to protect at least the portion of the automobile part located on the receiving side from collision with the receiving body. The impact absorbing member is configured to maintain the acceleration generated in the holder when the holder, which holds the automobile part, collides with the receiving body, for at least 1 / 8 milliseconds of the maximum acceleration of the holder, between 0.5 and the maximum acceleration.

8. The test equipment according to claim 7, The aforementioned shock-absorbing member is made of resin, and is part of the test equipment.

9. A method for impact testing of automobile parts using the test equipment described in any one of claims 1 to 8, A step of holding the automotive part to be tested in the holder, A step of causing the holder, which holds the automobile part, to collide with the receiving body, An impact testing method that includes the following features.

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