Wheel bench test equipment

Abstract

To provide a wheel bench test device that identifies vibration characteristics of a wheel in a running state on a table.SOLUTION: A wheel bench test device includes a support 10 having a cylindrical bottomed hollow part, a circumferential groove 11 that continues in a circumferential direction so as to have a radial width in a part of a bottom surface of the hollow part, a wheel attachment shaft 13, a sensor device 14 that is arranged in the wheel attachment shaft and detects reactive force generated in the wheel, a magnet 15 that is arranged with a clearance in the circumferential groove while being attached to the wheel attachment shaft, a plurality of electromagnetic coils 16 that are arranged opposite to the magnet in the inside and the outside in a radial direction of the circumferential groove to generate rotation drive force of the wheel attachment shaft while holding a non-contact state in cooperation with the magnet, a drive control unit 18 that performs current control for the plurality of electromagnetic coils, and a controller 17 that controls the drive control unit while receiving measurement data of the sensor device. The controller controls the plurality of electromagnetic coils through the drive control unit to rotate the wheel, which is attached to the wheel attachment shaft and whose ground contact surface is brought into contact with a side wall surface, along the side wall surface.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a wheelstand testing device for measuring vibration characteristics of wheels used in vehicles such as automobiles. [Background technology]

[0002] In general, in a vehicle such as an automobile, performance regarding road noise generated by the unevenness of the road surface as a vibration source can be evaluated by understanding the vibration characteristics of the wheels (tire wheels), for example.

[0003] Conventionally, various types of bench test devices that measure the vibration of a single wheel while the vehicle is running (i.e., when the wheel is in contact with the road surface and rolling) have been proposed, for example, in Patent Publication No. 2018-146508 and Patent Publication No. 2020-037299.

[0004] The wheel-bed testing device disclosed in JP 2018-146508 A and the like is a drum roller-type testing device that measures the reaction force acting on a tire running on the running surface of a drum. The publication discloses the structure of an inside-drum wheel-bed testing device in which the tire runs on the inner periphery of the drum. This testing device includes a first driving means for rotating the drum and a second driving means for running the tire, and measures the reaction force acting on the tire according to the speed difference between the drum and the tire.

[0005] Furthermore, the above-mentioned Japanese Patent Application Laid-Open No. 2020-037299 discloses a data correction method for obtaining accurate and highly precise tire uniformity data even for the frequencies of high-order components of a tire rotating at high speed. The publication also discloses the structure of a drum-type wheel-stand testing device in which a tire runs on the outer peripheral surface of a drum.

[0006] In addition to the drum roller type testing device described above, various types of conventional wheel bench testing devices, such as flat belt type testing devices, have been proposed and are generally in practical use. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Publication No. 2018-146508 [Patent Document 2] Japanese Patent Application Publication No. 2020-037299 Summary of the Invention [Problem to be solved by the invention]

[0008] However, in conventional wheel bench testing devices disclosed in the above-mentioned Patent Publication No. 2018-146508 and Patent Publication No. 2020-037299, etc., there is a high possibility that unintended input components (i.e., noise components) will be generated due to resonance of moving components such as drum rollers and flat belts, and the support bases or housings that fix and hold these moving components, as well as belt joints and drive system rotation orders.

[0009] Therefore, the wheel stand testing device of the above-described conventional configuration has a problem in that it is not possible to accurately measure the vibration characteristics of a single wheel in the vehicle road noise range (particularly in the range of 100 to 500 Hz).

[0010] The object of the present invention is to provide a wheel bench testing device that can accurately identify the vibration characteristics of a single wheel in a specified range of road noise on a bench while the vehicle is running (i.e., while the wheel is in contact with the road surface and rolling). [Means for solving the problem]

[0011] a plurality of electromagnetic coils arranged radially inward and outward from the circumferential groove to generate a driving force that rotates the wheel mounting shaft while maintaining a non-contact state; a drive control unit that controls the current to the plurality of electromagnetic coils; and a controller that controls the drive control unit and receives measurement data output from the sensor unit. The controller controls the plurality of electromagnetic coils via the drive control unit to cause the wheel, which is attached to the wheel mounting shaft and has a contact surface that contacts a side wall surface of the hollow section, to roll along the side wall surface. [Effects of the Invention]

[0012] According to the present invention, it is possible to provide a wheel bench testing device that can accurately identify the vibration characteristics of a single wheel of road noise in a specified range on a bench while the vehicle is running (i.e., while the wheel is in contact with the road surface and rolling). [Brief explanation of the drawings]

[0013] [Figure 1] FIG. 1 is a schematic perspective view showing the appearance of a wheel bench testing device according to an embodiment of the present invention. [Figure 2] FIG. 2 is a plan view of the wheel-bed test device of FIG. 1, seen from above the support base. [Figure 3] Cross-sectional view along line [3]-[3] in Figure 2 [Figure 4] Cross-sectional view along line [4]-[4] in Figure 2 [Figure 5]FIG. 2 is an enlarged view of a part of the wheel stand test device shown in FIG. 1; [Figure 6] A diagram showing the view from the direction of arrow [6] in Figure 5. DETAILED DESCRIPTION OF THE INVENTION

[0014] The present invention will be described below with reference to the illustrated embodiments. The drawings used in the following description are schematic, and the dimensional relationships and scales of the components may be different for each component in order to show each component at a size that allows it to be recognized on the drawing. Therefore, the present invention is not limited to the illustrated embodiments in terms of the number of components shown in the drawings, the shapes of the components, the size ratios of the components, the relative positional relationships of the components, and so on.

[0015] One embodiment of the present invention is a wheel bench test device that performs tests on a bench in a laboratory or the like that simulate the actual usage environment of the wheels (tires and wheels) being tested, and measures the reaction forces acting on the wheels while they are running.

[0016] FIG. 1 is a schematic perspective view showing the appearance of a wheelbed testing apparatus according to one embodiment of the present invention. FIG. 2 is a plan view of the wheelbed testing apparatus of FIG. 1, seen from above the support base. FIG. 3 is a cross-sectional view taken along line [3]-[3] in FIG. 2. FIG. 4 is a cross-sectional view taken along line [4]-[4] in FIG. 2. FIGS. 5 and 6 are conceptual diagrams showing the operation of the wheelbed testing apparatus according to this embodiment. Of these, FIG. 5 shows an enlarged view of a portion of FIG. 2. FIG. 6 shows the state as seen from the direction of the arrow [6] in FIG. 5.

[0017] 1 to 6 show a state in which a test object (wheel, i.e., tire and wheel) is installed in the wheelbed test apparatus of this embodiment. Also, in Fig. 2, a portion is cut away to show the arrangement of multiple electromagnetic coils provided inside the support base, and the electromagnetic coils in other internal regions are shown using dotted lines. Also, in Figs. 2 to 5, electrical components (17, 18) of the vehicle bed test apparatus of this embodiment are not shown.

[0018] First, the basic configuration of a wheel stand testing device according to one embodiment of the present invention will be described below with reference to the drawings.

[0019] As shown in Figures 1 to 4, the wheel stand testing device 1 of this embodiment is mainly composed of a support base 10, a wheel mounting shaft 13 (not shown in Figure 1), a sensor device 14 (not shown in Figures 1 and 2, see Figures 3 and 4), a magnet 15, multiple electromagnetic coils 16 (not shown in Figure 1), a controller 17 (shown only in Figure 1), a drive control unit 18 (shown only in Figure 1), etc.

[0020] The support base 10 is a support that is a basic component of the wheelstand testing device 1 of this embodiment. As shown in FIG. 1, the support base 10 is made of a flat housing overall. In this embodiment, the support base 10 is illustrated as a housing having a flat, approximately cylindrical shape overall, but the overall shape is not limited to this example. The basic shape of the support base 10 may be, for example, a flat, approximately cubic shape. This support base 10 is formed by processing a metal member or the like having high rigidity.

[0021] A hollow portion 10a having a substantially cylindrical shape and a bottom is formed inside the support base 10. The hollow portion 10a is made up of a space surrounded by an opening 10b, a side wall surface 10c, and a bottom surface 10d.

[0022] The opening 10b has a substantially circular shape that opens toward one surface of the support base 10 (the upper surface in FIG. 1), and is an opening of the hollow portion 10a.

[0023] The side wall surface 10c is a wall surface that is continuously formed in the circumferential direction along the outer peripheral edge of the opening 10b. The side wall surface 10c is formed as a surface that is perpendicular to the plane in which the opening 10b is formed and parallel to the central axis C of the hollow portion 10a of the support base 10.

[0024] As will be described later, the side wall surface 10c is the running surface on which the contact surface 20a (see FIGS. 5 and 6) of the wheel 20 (as a test object) contacts the ground and the wheel 20 rolls. For this reason, the support base 10 is ensured to have sufficient strength to withstand the wheel 20 rolling at a speed equivalent to, for example, 100 km / h. Furthermore, the surface of the side wall surface 10c is preferably formed with a shape or single protrusions (cleats) that imitate the road surface (e.g., asphalt road surface) used in actual vehicle running tests. This makes the side wall surface 10c suitable for reproducing the state in which the wheel 20 runs on a road. Note that the surface of the side wall surface 10c can also be configured such that various types of structures that imitate road surfaces can be detachably attached. Such ingenuity makes it possible to reproduce various running environments.

[0025] The bottom surface 10d is a floor surface formed in a position facing the opening 10b and parallel to the plane of the opening 10b. A bottomed circumferential groove 11 is formed in the bottom surface 10d at a position spaced a predetermined distance from the central axis C toward the outer periphery in the radial direction. The circumferential groove 11 has a predetermined width in the radial direction and is formed continuously in the circumferential direction. The radial position of the circumferential groove 11 is preferably near the outer periphery of the hollow portion 10a. In this embodiment, the circumferential groove 11 is formed near the outer periphery of the hollow portion 10a and at a predetermined distance from the side wall surface 10c toward the central axis C.

[0026] The wheel mounting shaft 13 is a shaft-shaped member to which the wheel 20, which serves as the test object, is attached. The wheel mounting shaft 13 is made of a hollow rod-shaped member. One end of the wheel mounting shaft 13 is provided with a mechanism for freely attaching and detaching the wheel 20. This wheel mounting and detaching mechanism is not shown in the figures, as it is assumed that a well-known configuration is applied. Specifically, the wheel mounting and detaching mechanism is made of well-known configuration, such as a hub and stud bolts that correspond to the wheel hub holes of the wheel 20. Note that when the wheel 20 is fixed to one end of the wheel mounting shaft 13, the central axis Ax of the wheel mounting shaft 13 is configured to approximately coincide with the center of rotation of the wheel 20.

[0027] Meanwhile, a magnet 15 is fixed to the other end of the wheel mounting shaft 13. A permanent magnet having a substantially circular disk shape is used as this magnet 15. In this case, the magnet 15 is formed so that a semicircular portion of the disk shape is the south pole and the other semicircular portion is the north pole (see FIG. 5 described below). Furthermore, when the magnet 15 is fixed to the other end of the wheel mounting shaft 13, the central axis of the wheel mounting shaft 13 and the center of the disk of the magnet 15 are substantially aligned. Then, when the magnet 15 is attached to the wheel mounting shaft 13, it is positioned inside the circumferential groove 11 with a predetermined gap between them.

[0028] As will be described in detail later, the magnet 15 rotates the wheel mounting shaft 13 around the central axis Ax while maintaining a non-contact state in cooperation with the multiple electromagnetic coils 16. At this time, the wheel 20 attached to one end of the wheel mounting shaft 13 also rotates in the same direction. The ground contact surface 20a of the wheel 20 is in contact with the side wall surface 10c of the support base 10. Therefore, when the wheel 20 rotates around the central axis Ax, the wheel 20 rolls along the side wall surface 10c. At this time, while rotating around the central axis Ax, the magnet 15 simultaneously rotates around the central axis C along the circumferential groove 11 while maintaining a non-contact state within the circumferential groove 11.

[0029] Although not shown in FIGS. 1 and 2, as shown in FIGS. 3 and 4, a sensor device 14 that detects the reaction force generated in the wheel 20 is disposed inside the wheel mounting shaft 13. This sensor device 14 may be, for example, an existing six-component force meter configured with a plurality of load cells. Measurement data (see symbol D in FIG. 1) and the like from this sensor device 14 are wirelessly transmitted in a non-contact manner, for example, by telemetry (remote measurement method). The measurement data and the like wirelessly transmitted from the sensor device 14 are received via an antenna 17a of the controller 17 and recorded in a storage medium or the like within the controller 17.

[0030] The electromagnetic coils 16 are arranged facing each other in the radially inner and outer regions across the circumferential groove 11. As a result, the electromagnetic coils 16 cooperate with the magnets 15 to generate a driving force that rotates the wheel mounting shaft 13 around the central axis Ax while maintaining a non-contact state (the operation will be described in detail later).

[0031] Here, the plurality of electromagnetic coils 16 are made up of a first group of electromagnetic coils 16A and a second group of electromagnetic coils 16B.

[0032] Of these, the first electromagnetic coil group 16A refers to a plurality of electromagnetic coils arranged in the radially outer region of the circumferential groove 11. Figures 2 to 4 show the positional relationship of a plurality of electromagnetic coils 16 arranged in the vicinity of the periphery of the magnet 15 when the magnet 15 is arranged at an arbitrary position within the circumferential groove 11 (the position shown in Figures 2 to 4).

[0033] First, as shown in Fig. 2, the first electromagnetic coil group 16A is made up of a plurality of electromagnetic coils arranged in a line in the circumferential direction along the outer edge of the circumferential groove 11 when viewed from the top surface side of the support base 10. In this case, in the first electromagnetic coil group 16A, adjacent electromagnetic coils 16 are arranged alternately in the up-down direction as shown in Figs.

[0034] That is, in the cross section shown in Fig. 3, the electromagnetic coil of the first electromagnetic coil group 16A designated by the symbol 16A(1) is shown by a two-dot chain line because it is located closer to the front side of the cross section taken along the line [3]-[3]. Also, in the cross section shown in Fig. 4, the electromagnetic coil 16A(1) is shown by a two-dot chain line because it is located closer to the front side of the cross section taken along the line [4]-[4]. This electromagnetic coil 16A(1) is disposed at an upper position in the vertical direction of the support base 10.

[0035] On the other hand, in the cross section shown in Fig. 3, the electromagnetic coil of the first electromagnetic coil group 16A designated by the symbol 16A(3) is located further back than the cross section taken along the line [3]-[3] and is therefore indicated by a solid line. Also, in the cross section shown in Fig. 4, the electromagnetic coil 16A(3) is located closer to the viewer than the cross section taken along the line [4]-[4] and is therefore indicated by a two-dot chain line. This electromagnetic coil 16A(3) is disposed at a lower position in the up-down direction of the support base 10. The electromagnetic coils 16A(1) and 16A(3) are disposed adjacent to each other in the circumferential direction as shown in Fig. 2.

[0036] Similarly, the second electromagnetic coil group 16B refers to a plurality of electromagnetic coils arranged in a radially inner region of the circumferential groove 11. Here, as shown in Fig. 2, the second electromagnetic coil group 16B is made up of a plurality of electromagnetic coils arranged side by side in the circumferential direction along the inner edge of the circumferential groove 11 when viewed from the top surface side of the support base 10. In this case, in the second electromagnetic coil group 16B, similar to the first electromagnetic coil group 16A, adjacent electromagnetic coils 16 are arranged alternately in the up-down direction as shown in Figs. 3 and 4.

[0037] That is, in the cross section shown in Fig. 3, the electromagnetic coil of the second electromagnetic coil group 16B designated by the symbol 16B(2) is located in front of the cross section taken along the line [3]-[3] and is therefore indicated by a two-dot chain line. Also, in the cross section shown in Fig. 4, the electromagnetic coil 16B(2) is located behind the cross section taken along the line [4]-[4] and is therefore indicated by a solid line. The electromagnetic coil 16B(2) is disposed at a lower position in the vertical direction of the support base 10.

[0038] On the other hand, in the cross section shown in Fig. 3, the electromagnetic coil of the second electromagnetic coil group 16B, designated by the symbol 16B(4), is located further back than the cross section taken along the line [3]-[3] and is therefore indicated by a solid line. Also, in the cross section shown in Fig. 4, the electromagnetic coil 16B(4) is located further back than the cross section taken along the line [4]-[4] and is therefore indicated by a solid line. This electromagnetic coil 16B(4) is disposed at an upper position in the up-down direction of the support base 10. The electromagnetic coils 16B(2) and 16B(4) are disposed adjacent to each other in the circumferential direction as shown in Fig. 2.

[0039] 2, the electromagnetic coil 16A(1) and the electromagnetic coil 16B(2) are arranged side by side with their central axes facing each other across the circumferential groove 11 in the radial direction of the support base 10. However, as shown in FIGS. 3 and 4, the electromagnetic coil 16A(1) and the electromagnetic coil 16B(2) are arranged with their positions shifted in the up-down direction.

[0040] Similarly, as shown in Fig. 2, the electromagnetic coil 16A(3) and the electromagnetic coil 16B(4) are arranged side by side with their central axes facing each other across the circumferential groove 11 in the radial direction of the support base 10. However, as shown in Figs. 3 and 4, the electromagnetic coil 16A(3) and the electromagnetic coil 16B(4) are arranged with their positions shifted in the up-down direction.

[0041] 3, the electromagnetic coil 16A(1) and the electromagnetic coil 16B(4) are disposed at upper positions in the vertical direction of the support base 10. However, as shown in FIGS. 2 and 4, the electromagnetic coil 16A(1) and the electromagnetic coil 16B(4) are disposed with their positions shifted in the circumferential direction.

[0042] 3, the electromagnetic coil 16A(3) and the electromagnetic coil 16B(2) are disposed at a lower position in the up-down direction of the support base 10. However, as shown in FIGS. 2 and 4, the electromagnetic coil 16A(3) and the electromagnetic coil 16B(2) are disposed with their positions shifted in the circumferential direction.

[0043] The drive control unit 18 is a component unit that supplies and controls current to the multiple electromagnetic coils 16, thereby controlling the rotation of the magnet 15. To this end, the drive control unit 18 is connected to the multiple electromagnetic coils 16 and a controller 17. An AC power supply (not shown) is connected to the drive control unit 18, and the drive control unit 18 is configured to be able to receive power from a commercial power source or the like.

[0044] The controller 17 is a control device including a processor that performs overall electrical control of the wheel stand testing apparatus 1 of this embodiment. Therefore, the drive control unit 18 is controlled by the user of the wheel stand testing apparatus 1 operating the controller 17.

[0045] That is, when the user operates the controller 17, switching control is performed via the drive control unit 18 to appropriately change the current flowing through each of the multiple electromagnetic coils 16. This control applies a predetermined rotational driving force to the magnet 15 while maintaining a non-contact state. As the magnet 15 rotates, the wheel mounting shaft 13 rotates around the central axis Ax. At this time, by controlling the amount of current and on / off timing for each electromagnetic coil 16, it is possible to appropriately control the rotation direction and number of rotations per unit time (rotational speed) of the magnet 15, as well as the magnetic force difference between the first electromagnetic coil group 16A and the second electromagnetic coil group 16B.

[0046] As described above, the controller 17 is a control device including a processor that performs overall electrical control of the wheel-stand testing apparatus 1. The controller 17 controls, for example, the drive control unit 18 in response to an operation by a user.

[0047] More specifically, the controller 17 controls the multiple electromagnetic coils 16 through the drive control unit 18. As a result, the controller 17 causes the magnet 15 and the multiple electromagnetic coils 16 to cooperate with each other to rotate the wheel mounting shaft 13. When the wheel mounting shaft 13 rotates, the wheel 20 attached to the wheel mounting shaft 13 also rotates in the same direction. At this time, by controlling the multiple electromagnetic coils 16, the contact surface 20a of the wheel 20 is brought into contact with the side wall surface 10c of the hollow portion 10a. In other words, the radial positions of the magnet 15 and the wheel 20 are controlled by controlling the magnetic force difference between the first electromagnetic coil group 16A and the second electromagnetic coil group 16B in the multiple electromagnetic coils 16. As a result, the contact surface 20a of the wheel 20 is pressed against the side wall surface 10c of the hollow portion 10a of the support base 10 with a predetermined pressure. Therefore, the frictional force generated between the ground contact surface 20a of the wheel 20 and the side wall surface 10c of the hollow portion 10a causes the wheel 20 to roll along the side wall surface 10c (details of this operation will be described later). Note that under normal circumstances, the ground contact surface 20a is controlled to contact the side wall surface 10c with approximately 1 G.

[0048] The controller 17 has an antenna 17a, which receives measurement data and the like output from the sensor device 14 by wireless transmission.

[0049] Furthermore, the controller 17 has an internal storage device (not shown) in which measurement data etc. from the sensor device 14 is accumulated and stored, and software programs etc. for controlling the electromagnetic coil 16 etc. are stored in advance.

[0050] Here, for example, the controller 17 is configured by a processor that includes all or part of hardware. This processor is configured by a well-known configuration including, for example, a central processing unit (CPU), random access memory (RAM), read only memory (ROM), non-volatile memory, non-volatile storage, and a non-transitory computer readable medium, as well as peripheral devices thereof.

[0051] Software programs to be executed by the CPU and fixed data such as data tables are stored in advance in ROM, non-volatile memory, non-volatile storage devices, etc. The CPU reads out the software programs stored in ROM, etc., expands them into RAM, and executes them, and the software programs refer to various data, etc. as appropriate, thereby realizing various functions based on various controls.

[0052] The processor may be configured with a semiconductor chip such as an FPGA (Field Programmable Gate Array), etc. Furthermore, the above-mentioned components and component units (12, 20b, 21d, 22, 23, 24, 25) may be configured with electronic circuits.

[0053] Furthermore, the software program may be in a form in which the whole or part of the software program is recorded as a computer program product on a portable storage medium such as a flexible disk, CD-ROM, or DVD-ROM, or on a non-transitory computer readable medium such as a card-type memory, HDD (Hard Disk Drive), or SSD (Solid State Drive).The above is the general configuration of the wheel-stand testing device 1 of this embodiment.

[0054] Next, a brief description will be given below of the operation when a wheel 20 as a test object is placed on the wheel stand testing device 1 of this embodiment and vibration characteristics are measured.

[0055] First, the wheel 20 as the test object is attached to one end of the wheel mounting shaft 13 by a predetermined fixing means. Then, with the wheel 20 fixed to one end, the magnet 15 at the other end of the wheel mounting shaft 13 is placed inside the circumferential groove 11 of the support base 10.

[0056] In this state, the user (tester) of the wheel stand testing device 1 appropriately operates the controller 17 to control the current to the multiple electromagnetic coils 16 via the drive control unit 18. In other words, by energizing the electromagnetic coils 16, a magnetic field is generated inside the electromagnetic coils 16, generating a Lorentz force of a predetermined magnitude in an appropriate direction. This controls the rotation of the magnet 15 (wheel 20) and the pressing force of the wheel 20 against the side wall surface 10c.

[0057] More specifically, the current control of the electromagnetic coil 16 is performed, for example, as follows: For example, assume that the magnet 15 is located inside the circumferential groove 11 and is surrounded by multiple electromagnetic coils 16A(1), 16A(3), 16B(2), and 16B(4), as shown in Figures 5 and 6.

[0058] At this time, the north pole of the magnet 15 is positioned toward the inside of the circumferential groove 11, and the south pole is positioned toward the outside of the circumferential groove 11. In this state, current control is performed on the electromagnetic coil 16A(1) so that the magnetic pole facing the south pole of the magnet 15 becomes the north pole. As a result, an attractive force acts between the magnet 15 and the electromagnetic coil 16A(1), as shown by arrow Ad1. Therefore, the magnet 15 (wheel mounting shaft 13, wheel 20) rotates in the direction of arrow R1 in FIG. 5.

[0059] At the same time, current control is performed on the electromagnetic coil 16A(3) so that the magnetic pole facing the south pole of the magnet 15 becomes the south pole. As a result, a repulsive force acts between the magnet 15 and the electromagnetic coil 16A(3), as shown by arrow Re3. Therefore, the magnet 15 (wheel mounting shaft 13, wheel 20) rotates in the direction of arrow R2 in FIG. 5.

[0060] At the same time, current control is performed on the electromagnetic coil 16B(2) so that the magnetic pole facing the N pole of the magnet 15 becomes the N pole. As a result, a repulsive force acts between the magnet 15 and the electromagnetic coil 16B(2), as shown by arrow Re2. Therefore, the magnet 15 (wheel mounting shaft 13, wheel 20) rotates in the direction of arrow R1 in FIG. 5.

[0061] At the same time, current control is performed on the electromagnetic coil 16B(4) so ​​that the magnetic pole facing the north pole of the magnet 15 becomes the south pole. As a result, an attractive force acts between the magnet 15 and the electromagnetic coil 16B(4), as shown by arrow Ad4. Therefore, the magnet 15 (wheel mounting shaft 13, wheel 20) rotates in the direction of arrow R2 in FIG. 5.

[0062] In this way, the magnet 15 rotates in the direction of arrow R in Figures 5 and 6 around the central axis Ax of the wheel mounting shaft 13. When the magnet 15 rotates, the wheel 20, which is coaxially mounted by the wheel mounting shaft 13, also rotates in the same direction. The contact surface 20a of the wheel 20 is in contact with the side wall surface 10c. Therefore, the wheel 20 rolls along the side wall surface 10c.

[0063] When the wheel 20 rolls along the side wall surface 10c, the magnet 15 moves circumferentially within the circumferential groove 11 while continuing to rotate in the R direction around the central axis Ax. This also changes the positional relationship of the magnet 15 with respect to the multiple electromagnetic coils 16. Therefore, current control for the multiple electromagnetic coils 16 is performed appropriately in accordance with the rotation and movement of the magnet 15.

[0064] At the same time, current control is performed appropriately so that a magnetic force difference occurs between the electromagnetic coils 16A(1) and 16A(3) on the first electromagnetic coil group 16A side and the electromagnetic coils 16B(2) and 16B(4) on the second electromagnetic coil group 16B side. This controls the amount of force with which the contact surface 20a of the wheel 20 is pressed against the side wall surface 10c. The amount of pressing force in this case is set appropriately according to the set speed at which the wheel 20 travels.

[0065] At this time, when the wheel 20 rolls along the side wall surface 10c, centrifugal force acts on the wheel 20. Therefore, when a magnetic force difference is generated between the first electromagnetic coil group 16A and the second electromagnetic coil group 16B and the amount of force pressing the contact surface 20a of the wheel 20 against the side wall surface 10c is controlled, this centrifugal force is also taken into consideration when setting the amount of force.

[0066] In this way, a wheel load corresponding to the running state is applied to the wheel 20 due to the magnetic force difference between the outer electromagnetic coils 16A(1), 16A(3) and the inner electromagnetic coils 16B(2), 16B(4) and the centrifugal force generated as the wheel 20 rolls along the side wall surface 10c.

[0067] In this state, the measurement data from the sensor device 14 is input to and recorded by the controller 17. In this manner, in the wheel stand testing apparatus 1 of this embodiment, measurement data of vibration characteristics is obtained for the wheel 20 simulating a running state.

[0068] As described above, according to the embodiment, the non-contact electromagnetic motor device is configured using the magnet 15 and the multiple electromagnetic coils 16, so that it is possible to apply a rotational driving force to the wheel 20, which is the test object, while maintaining a non-contact state. In addition, since the support base 10 is configured from a single member with sufficient rigidity, it is possible to suppress the occurrence of resonance and the like from the test device.

[0069] Therefore, when measuring vibration characteristics in a state close to the actual use environment of the wheel 20 (driving state), it is possible to eliminate unnecessary vibrations caused by resonance of the components and housing of the wheel bench test apparatus 1. It is also possible to remove disturbances such as rotational order components of the rotary drive device (motor). This makes it possible to eliminate disturbances as much as possible in the bench test of the wheel 20, thereby enabling more accurate measurement data to be obtained.

[0070] Furthermore, since the surface of the side wall surface 10c of the support base 10 is formed into various shapes that imitate the road surface, the actual traveling environment of the wheel 20 can be reproduced more accurately.

[0071] In this embodiment, the wheels 20 roll along the side wall surface 10c to simulate a running state. In this case, the side wall surface 10c is the inner wall surface of the cylindrical support base 10. Therefore, in this embodiment, the wheels 20 roll along such side wall surface 10c to simulate a running state.

[0072] When the wheels run along the inner circumference of the cylinder in this way, centrifugal force acts on the wheels 20, generating a wheel load. At this time, the centrifugal force increases as the rolling speed of the wheels 20 increases. Therefore, the wheel load also increases according to the assumed vehicle speed during running.

[0073] However, the desired wheel load cannot be reproduced by centrifugal force alone. For this reason, in the wheel stand testing device 1 of this embodiment, the wheel load is reproduced by controlling the multiple electromagnetic coils 16. That is, by controlling the magnetic force difference between the outer first electromagnetic coil group 16A and the inner second electromagnetic coil group 16B, an appropriate wheel load according to the assumed speed range is obtained. This makes it possible to reproduce the actual running environment of the wheel 20.

[0074] By using the acquired measurement data on vibration characteristics, it is possible to easily and accurately identify the road noise (particularly in the 100 to 500 Hz range) and vibration characteristics of the test object (wheel 20) alone during actual driving. This can lead to the proposal of required tire characteristics for road noise performance, for example.

[0075] It can also be applied to experimental measurements of noise emitted from tires, which is important in complying with vehicle exterior noise regulations.

[0076] In the embodiment described above, the magnet 15 is an approximately disk-shaped permanent magnet, but the shape of the magnet 15 is not limited to this. For example, a configuration in which the magnet 15 is in the shape of a curved rod is also conceivable. In this case, the configuration shown below may be adopted.

[0077] A pair of arc-shaped or bow-shaped bar magnets that fit along the radially outer and inner wall surfaces of the circumferential groove 11 are attached to the outer peripheral surface of the other end of the wheel mounting shaft 13. In this case, one of the pair of bar magnets faces the inner wall surface of the circumferential groove 11, and the other faces the outer wall surface of the circumferential groove 11. The pair of bar magnets are also arranged so that their north and south poles are aligned in the circumferential direction of the circumferential groove 11. A wheel 20 is attached to one end of the wheel mounting shaft 13 via a hub unit (axle bearing). The wheel 20 is rotatable relative to the wheel mounting shaft 13. The wheel 20 is also grounded to the inner wall surface 10c of the base 10. In this configuration, the hub unit (axle bearing) needs to be designed not to resonate.

[0078] With this configuration, by controlling the energization of the electromagnetic coil 16, the integrated unit of the magnet, wheel mounting shaft, and wheel moves (revolves) along the circumferential groove 11. At this time, the wheel 20 runs (rotates) due to friction with the inner wall surface 10c of the base 10. Therefore, even with this configuration, it is possible to obtain substantially the same functions and effects as the above-described embodiment.

[0079] The present invention is not limited to the above-described embodiments, and various modifications and applications can be made without departing from the spirit and scope of the invention. Furthermore, the above-described embodiments include inventions at various stages, and various inventions can be extracted by appropriately combining the disclosed multiple constituent elements. For example, if the problem to be solved by the invention can be solved and the effects of the invention can be obtained even if some constituent elements are deleted from all the constituent elements shown in one embodiment, the configuration from which these constituent elements are deleted can be extracted as the invention. Furthermore, constituent elements from different embodiments may be appropriately combined. The present invention is not limited by specific embodiments other than as limited by the appended claims. [Explanation of symbols]

[0080] 1...Wheel bench test equipment 10…Support base (support body) 10a...Hollow part 10b…Aperture 10c...Side wall 10d...bottom 11...Peripheral groove 13...Wheel mounting shaft 14...Sensor device 15...Magnet 16...Electromagnetic coil 16A...First electromagnetic coil group 16B...Second electromagnetic coil group 17...Controller 17a...Antenna 18...Drive control unit 20...Wheel 20a…ground plane Ax...Central axis (wheel mounting axis, wheel) C...Central axis (support base, hollow part)

Claims

1. A wheel bench test device that measures reaction forces acting on wheels while the vehicle is running, a support body having a cylindrical shape and a hollow portion with a bottom; a circumferential groove formed in a part of a bottom surface of the hollow portion of the support body, the circumferential groove having a width in a radial direction and continuously formed in a circumferential direction; a wheel mounting shaft for mounting the wheel; a sensor device disposed on the wheel mounting shaft for detecting a reaction force generated on the wheel; a magnet that is disposed with a gap in the circumferential groove when attached to the wheel mounting shaft; a plurality of electromagnetic coils disposed in radially inner and outer regions of the circumferential groove facing the magnet, and cooperating with the magnet to generate a driving force that rotates the wheel mounting shaft while maintaining a non-contact state; a drive control unit that controls current to the plurality of electromagnetic coils; a controller that controls the drive control unit and receives measurement data output from the sensor device; Equipped with The wheel-bed testing device is characterized in that the controller controls the plurality of electromagnetic coils through the drive control unit, thereby causing the wheel, which is attached to the wheel mounting shaft and has its contact surface in contact with the side wall surface of the hollow portion, to roll along the side wall surface.

2. the plurality of electromagnetic coils include a first electromagnetic coil group arranged in a radially outer region of the circumferential groove and a second electromagnetic coil group arranged in a radially inner region of the circumferential groove, 2. The wheel stand testing device according to claim 1, wherein the drive control unit obtains the wheel load of the wheel by performing control to generate a magnetic force difference between the first electromagnetic coil group and the second electromagnetic coil group.

3. 3. The wheel-stand testing device according to claim 1, wherein the side wall surface of the hollow portion is subjected to a predetermined surface treatment that simulates road surface conditions.

4. 3. The wheel-stand testing device according to claim 1, wherein a plurality of surface structures simulating road surface conditions are selectively and detachably provided on the side wall surface of the hollow portion.

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