Vehicle Test Equipment

Abstract

To obtain a vehicle testing device such as a chassis dynamo meter that can automatically set the position of a roller rotation mechanism so as to prevent the occurrence of tire position deviation phenomenon during execution of a running test.SOLUTION: A control unit 80 receives detection speeds V1 and V2 obtained from rotation detectors 81 and 82, and controls a roller rotation mechanism 3, a position changing mechanism MV, and a front roller 20F to execute rotation center setting processing. In step S6, the rotation center setting processing calculates a plurality of speed differences for determination (sum of speed differences SMV, maximum speed difference MXV, and the like) corresponding to a plurality of set positions based on the speed difference ΔV1 at each of the plurality of set positions, and determines the set position corresponding to the speed difference for determination being the minimum value, of the plurality of speed differences for determination, as the optimal set position. Subsequently, in step S7, the rotation center setting processing moves the roller rotation mechanism 3 to the optimal set position determined in step S6.SELECTED DRAWING: Figure 11

Description

[Technical field]

[0001] The present disclosure relates to a vehicle testing device such as a chassis dynamometer used for various running tests of a vehicle. [Background technology]

[0002] Chassis dynamometers, which are one type of vehicle testing equipment, have been conventionally used when conducting running tests of vehicles (automobiles) and include a roller device as a main component. In addition, chassis dynamometers have a vehicle fixing mechanism that fixes the vehicle placed on the roller device when conducting a running test. For example, a chassis dynamometer disclosed in Patent Document 1 is an example of a conventional chassis dynamometer.

[0003] To carry out various driving tests involving vehicle steering operations, it is necessary to perform a roller turning operation to turn the rollers to match the turning operation of the tires. In other words, the roller turning operation is necessary to realize a control method for making the roller devices for the left and right tires follow the turning angle of the tires caused by steering operations. The above control method can be applied to autonomous driving and ADAS simulated driving tests. "ADAS (Advanced Driver Assistance System)" means "advanced driving system" and is a system that detects the possibility of accidents and other events in advance and avoids them.

[0004] In order to carry out various running tests associated with the steering operation of the vehicle as described above, the conventional chassis dynamometer further includes a roller turning mechanism that performs a roller turning operation. The chassis dynamometer disclosed in the above-mentioned Patent Document 1 includes the roller turning mechanism. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2019-203869 A Summary of the Invention [Problem to be solved by the invention]

[0006] In conventional running tests using a chassis dynamometer, the vehicle's tires are placed and fixed on the rollers of a roller device. The center of rotation of the tire is affected by the kingpin position, caster angle, camber angle, etc. of the vehicle, and may differ from the center of the tire contact surface, and also differs depending on the vehicle model.

[0007] Therefore, there is a possibility that a positional deviation occurs between the rotation center of the roller and the rotation center of the tire at the start of the running test. Hereinafter, the positional deviation between the rotation center of the roller and the rotation center of the tire may be referred to as "positional deviation between the rotation centers."

[0008] 26 is an explanatory diagram showing a problem with a conventional chassis dynamometer. Fig. 26 shows a roller device having a twin roller configuration with a roller pair 20.

[0009] 26, the front roller 20F is used as a load roller, and the rear roller 20R is used as a free roller. Therefore, the tire rotation direction K2F of the front roller 20F and the tire rotation direction K6 of the tire 6 are in an opposite relationship, and the tire rotation direction K6 of the tire 6 and the tire rotation direction K2R of the rear roller 20R are in an opposite relationship.

[0010] 26(a) and (b) are plan and side views showing the positional relationship between the roller pair 20 (20F, 20B) and the tire 6 when the vehicle is moving straight ahead (initial state), and Fig. 26(c) and (d) are plan and side views showing the positional relationship between the roller pair 20 and the tire 6 when the tire 6 of the vehicle and the roller pair 20 are turned. An XYZ Cartesian coordinate system is depicted in each of Figs. 26(a) to (d).

[0011] In addition, the X-axis and Y-axis shown in Figures 26(c) and (d) are made to coincide with the X-axis and Y-axis in Figures 26(a) and (b) for the sake of ease of comparison with Figures 26(a) and (b). In reality, the relationship between the tire 6 and the roller pair 20 and the X-axis and Y-axis changes with the roller turning operation and the tire turning operation.

[0012] 26, the roller turning mechanism (not shown) can perform a roller turning operation to turn the roller pair 20 around the roller turning center C2 along the roller turning direction R2. Meanwhile, the vehicle 60 can perform a tire turning operation as described above.

[0013] The bed 65 is a base on which the roller pair 20 is mounted, and the roller bearings 66 and 67 are components necessary for the rotational drive of the front roller 20F and the rear roller 20R of the roller pair 20, respectively.

[0014] Hereinafter, problems with the roller device 2 having the roller pair 20 will be described with reference to Fig. 26. As shown in Fig. 26, the roller pair 20 has a twin-roller configuration with a front roller 20F at the front and a rear roller 20R at the rear. The diameters of the front roller 20F and the rear roller 20R are set to be smaller than the diameter of the tire 6.

[0015] 26(a) and 26(b), in the initial state where the tire 6 is placed on the roller pair 20, the roller turning center C2 is shifted rearward and to the right with respect to the tire turning center C6. That is, a deviation amount DX2 occurs in the X direction between the roller turning center C2 and the tire turning center C6, and a deviation amount DY2 occurs in the Y direction. In this way, in the initial state, a positional deviation amount between the turning centers occurs due to the deviation amount DX2 and the deviation amount DY2.

[0016] As shown in FIGS. 26(a) and 26(b), when the vehicle 60 is traveling straight, there is no effect from the positional deviation between the turning centers, and the initial state does not change.

[0017] However, as shown in Figures 26(c) and (d), when a tire turning operation and a roller turning operation are performed, the positional relationship between the roller pair 20 and the tire 6 changes significantly even if the tire 6 and the roller pair 20 are moved to match their respective turning angles.

[0018] A comparison of the tire contact surface 6G shown in Figures 26(a) and (c) reveals that a deviation ΔX12 occurs in the X direction. A comparison of the tire contact surface 6G shown in Figures 26(c) and (d) reveals that a deviation ΔY12 occurs in the Y direction. Note that Figure 26(c) shows the position of the tire contact surface P6G in the initial state. A comparison of the top 6T of the tire 6 shown in Figures 26(b) and (d) reveals that a deviation ΔZ12 occurs in the Z direction.

[0019] In this way, when a running test involving tire turning and roller turning is performed on the vehicle 60, a tire position shift phenomenon occurs in the direction in which the tire turning center C6 approaches the roller turning center C2. In particular, if the roller pairs 20 are made small in order to reduce interference between the left and right roller devices 2 during turning and between the roller pairs 20 in order to increase the turning angle of the tire 6, the vehicle 60 moves up and down, and the height of the vehicle 60 is likely to fluctuate.

[0020] A conventional chassis dynamometer is configured as described above, and when a tire 6 of a vehicle 60 is placed on the roller pair 20 of the roller device 2, there is a possibility that a positional deviation between the tire rotation center C6 and the roller rotation center C2 may occur.

[0021] One of the reasons for the misalignment between the turning centers is thought to be that the contact position between the roller pair 20 and the tire 6 is shifted from the desired contact position due to the mounting condition of the tire 6 on the vehicle 60 (toe angle, caster angle, camber angle, kingpin position, etc.).

[0022] When such a positional deviation between the turning centers occurs, if a running test of the vehicle 60 involving tire turning motion and roller turning motion is performed using a conventional chassis dynamometer, the above-mentioned tire positional deviation phenomenon will occur.

[0023] Due to the occurrence of the tire position shift phenomenon, the contact position between the tire 6 and the roller pair 20 shifts, causing the tire 6 to skid on the roller pair 20, which may cause the vehicle 60 to wobble. Also, as shown in Fig. 26(d), of the front roller 20F and the rear roller 20R, the rear roller 20R and the tire 6 will no longer be in contact with each other.

[0024] If a running test of vehicle 60 is performed on chassis dynamometer 1 when such a tire position deviation phenomenon occurs, the contact state of tire 6 with roller pair 20 will change, and the normal load will not be applied to tire 6 or the vehicle 60 will shake, affecting the image captured by the camera mounted on vehicle 60.

[0025] As described above, conventional vehicle testing devices, such as chassis dynamometers, had a problem in that they were unable to perform accurate running tests of vehicles involving tire turning and roller turning movements due to the occurrence of tire position shifting caused by position shift between the turning centers.

[0026] In general, the tire turning center C6 of the vehicle 60 is different from the tread value listed in the catalog of the vehicle 60, and therefore accurate numerical information is often not recognized. In this case, the tire turning center C6 needs to be manually confirmed, which is a relatively time-consuming task.

[0027] In addition, the task of positioning the roller turning mechanism so that the tire turning center C6 and the roller turning center C2 coincide is a manual task that is performed by turning the roller device 2 and checking the lifting of the tire 6. This task requires the skill of the worker and is extremely difficult because it requires a lot of time and effort.

[0028] The present disclosure has been made to solve the above-mentioned problems, and aims to provide a vehicle testing device such as a chassis dynamometer that can automatically set the position of a roller turning mechanism so that tire position deviation does not occur when a driving test is performed. [Means for solving the problem]

[0029] A vehicle testing device according to the present disclosure is a vehicle testing device including a roller device and a control unit, the roller device including first and second rollers on which a vehicle tire is placed, a roller drive mechanism that executes a roller drive operation to rotate the first roller, a first rotation detector that detects the rotation speed of the first roller to obtain a first detected speed, a second rotation detector that detects the rotation speed of the second roller to obtain a second detected speed, a roller turning mechanism that executes a roller turning operation to turn the first and second rollers, and a position changing mechanism that executes a position changing process to change the position of the roller turning mechanism with respect to a tire turning center of a tire placed on the first and second rollers, the first roller is used as a load roller that rotates and drives itself, and the second roller is used as a free roller that rotates in conjunction with the rotation of a tire, the control unit receives the first and second detected velocities and controls the roller drive mechanism, the turning mechanism, and the position change mechanism to execute the roller drive operation, the roller turning operation, and the position change process, a plurality of set positions are prepared as the position of the roller turning mechanism relative to the tire turning center, the control unit sets the roller turning mechanism to an initial setting position included in the plurality of set positions, and executes a turning center setting process in a state where the tires of the vehicle are placed and fixed on the first and second rollers, and the turning center setting process includes the steps of: (a) (b) executing the roller turning operation and the roller driving operation, and rotating the first roller to perform a temporary running test of the vehicle with the first and second rollers set in a predetermined turning direction, and obtaining the first and second detection speeds; (b) executing the position change process, and changing the position of the roller turning mechanism to a new set position included in the plurality of set positions; (c) repeatedly executing the steps (a) and (b) until the step (a) is executed at all of the plurality of set positions; (d) calculating a plurality of speed differences for judgment corresponding to the plurality of set positions based on a detection speed difference between the first and second detection speeds at each of the plurality of set positions, and determining the set position corresponding to the speed difference for judgment that is the smallest value among the plurality of speed differences for judgment as an optimal set position; and (e)and executing the position change process to move the roller turning mechanism to the optimum setting position. Effect of the Invention

[0030] In the vehicle testing apparatus disclosed herein, the control unit executes the above-mentioned turning center setting process, thereby automatically positioning the roller turning mechanism at the optimal setting position corresponding to the judgment speed difference that is the smallest among multiple judgment speed differences.

[0031] Therefore, the vehicle testing apparatus disclosed herein can automatically set the position of the roller turning mechanism so that the tire turning center of the tire and the roller turning centers of the first and second rollers are in the closest positional relationship, ideally so that the roller turning center coincides with the tire turning center.

[0032] As a result, the vehicle testing device of the present disclosure can perform various driving tests on a vehicle with high accuracy without causing the tire position deviation phenomenon during the running test. [Brief description of the drawings]

[0033] [Figure 1] 1 is a perspective view showing a schematic configuration of the chassis dynamometer of the first embodiment after a vehicle is placed thereon. [Diagram 2] 1 is a front view showing a structure of a roller device used in a chassis dynamometer according to a first embodiment. [Diagram 3] 3 is a top view of the AA cross section of FIG. 2 viewed from above. [Figure 4] 3 is a top view of the cross section BB in FIG. 2 viewed from above. [Diagram 5] 3 is a top view of the CC cross section of FIG. 2 viewed from above. [Figure 6] 3 is a top view of the cross section DD in FIG. 2 viewed from above. [Figure 7] FIG. 4 is an explanatory diagram illustrating a planar arrangement of a roller pair; [Figure 8] FIG. 4 is an explanatory diagram illustrating a side arrangement of the roller device. [Figure 9] 8 is an explanatory diagram illustrating a schematic cross-sectional structure taken along the E-E cross section of FIG. 7. [Figure 10] 8 is an explanatory diagram showing a schematic cross-sectional structure taken along the line FF in FIG. 7. [Figure 11] FIG. 4 is an explanatory diagram illustrating a control system of the roller device. [Figure 12] 5 is a flowchart showing a processing procedure of a method for moving a roller turning mechanism using a chassis dynamometer according to the present embodiment. [Figure 13] 13 is a flowchart showing the processing content of the load roller acceleration / deceleration processing shown in FIG. 12. [Figure 14] 13 is a flowchart showing the process contents of the position change process shown in FIG. 12. [Figure 15] 15 is a flowchart showing the process contents of the position change process shown in FIG. 14. [Figure 16] FIG. 16 is an explanatory diagram showing the execution contents of the left / right direction movement routine shown in FIG. [Figure 17] 11 is an explanatory diagram (part 1) showing a state of the roller device according to the embodiment when a left-right direction movement routine is executed. FIG. [Figure 18] 13 is an explanatory diagram (part 2) showing the state of the roller device according to the embodiment when the left-right direction movement routine is executed. FIG. [Figure 19] FIG. 16 is an explanatory diagram showing the execution contents of the forward / backward movement routine shown in FIG. [Figure 20] 11 is an explanatory diagram (part 1) showing a state of the roller device according to the embodiment when a forward / rearward movement routine is executed. FIG. [Figure 21] 13 is an explanatory diagram (part 2) showing the state of the roller device according to the embodiment when the forward / rearward movement routine is executed. FIG. [Figure 22] 11 is an explanatory diagram showing, in a table format, an example of coordinates of a plurality of set positions of a roller turning mechanism and a processing procedure. FIG. [Figure 23] 13 is a flowchart showing a first processing procedure of the optimum setting position determination processing shown in FIG. [Figure 24]13 is a flowchart showing a second processing procedure of the optimum setting position determination processing shown in FIG. [Diagram 25] 1 is an explanatory diagram showing an effect of the chassis dynamometer according to an embodiment of the present invention; [Figure 26] 1 is an explanatory diagram illustrating a problem with a conventional chassis dynamometer. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0034] <Embodiment Mode> (principle) 26(d), when the rear roller 20R, which is a free roller, stops rotating, a large speed difference occurs between the rotation speed of the front roller 20F and the rotation speed of the rear roller 20R. In this way, the speed difference between the rotation speed of the front roller 20F and the rotation speed of the rear roller 20R is a useful indicator of the positional relationship between the roller rotation center C2 and the tire rotation center C6.

[0035] The vehicle testing device of the present disclosure focuses on the difference in rotation speed between the front rollers 20F, which act as load rollers, and the rear rollers 20R, which act as free rollers.

[0036] (Overall composition) Fig. 1 is a perspective view showing a schematic configuration of a chassis dynamometer 1 according to an embodiment after a vehicle 60 is placed on it. An XYZ orthogonal coordinate system is shown in Fig. 1. In this embodiment, the chassis dynamometer 1 is used as a vehicle testing device.

[0037] As shown in Fig. 1, four tires 6 of a vehicle 60 are placed on the roller pairs 20 of the four roller devices 2. Each roller device 2 has a roller pair 20 on which the tires 6 of the vehicle 60 are placed. Furthermore, the vehicle 60 is fixed in a state in which it is placed on the roller pairs 20 of the four roller devices 2 by a vehicle fixing means (not shown). At this time, the vehicle 60 is placed so as to be symmetrical with respect to a center line CL between the left and right roller devices 2, 2.

[0038] A rectangular image simulator 62 with its longitudinal direction in the X direction and its short side direction in the Z direction is provided on the floor surface 50 in front of the vehicle 60 (+Y direction). The image simulator 62, which is a simulation auxiliary member, has a display function for displaying the entire scenery that can be visually recognized from the vehicle 60.

[0039] The vehicle 60 may also have an external sensor (not shown). Possible external sensors include a radar and a lidar (LiDAR) used as a corner sensor, a side camera (side electronic mirror), and the like.

[0040] The chassis dynamometer 1 uses angle information of the tires 6 of the vehicle 60, an image simulator 62, etc. as necessary, and receives information from the external sensors of the vehicle 60 as necessary, to perform a running test on the vehicle 60. The running test includes a test accompanied by a tire turning operation in which the tires 6 of the vehicle 60 are turned, and a roller turning operation in which the roller pair 20 is turned in conjunction with the tire turning operation.

[0041] (Roller device 2) Fig. 2 is a front view showing the structure of the roller device 2 used in the chassis dynamometer 1 of this embodiment. Fig. 2 shows a front view seen from the rear (-Y direction). An XYZ orthogonal coordinate system is depicted in Fig. 2. When the two tires 6 on the front wheel side of the vehicle 60 perform a tire turning operation due to a steering operation, the roller devices 2 shown in Fig. 2 are used as at least the two roller devices on the front wheel side.

[0042] As shown in the figure, the roller device 2 is mounted on a base stand 25 and includes a forward / backward movement mechanism 5B, a left / right movement mechanism 4B, a roller rotating mechanism 3, a left / right movement mechanism 4T, a forward / backward movement mechanism 5T and a roller drive mechanism 8 as its main components.

[0043] The first forward / backward movement mechanism 5B is provided on the base table 25, and includes as its main components a drive motor 40, rails 51, guides 55, and a movable carriage 30. The movable carriage 30, which is the first forward / backward movement bed, is movable along the rails 51 in the Y direction, which is the forward / backward direction.

[0044] Fig. 3 is a top view of the AA cross section of Fig. 2 as viewed from above (+Z direction). As shown in Fig. 3, a pair of rails 51 are provided parallel to each other along the Y direction on the base stand 25. A plurality of guides 55 (two guides 55 are shown in Fig. 3) are provided on each rail 51. As shown in Fig. 2, a movable carriage 30 serving as a first forward / rearward moving bed is fixed to the upper surface of each guide 55.

[0045] 2 and 3, a drive motor 40, which is a first forward / rearward motor, is provided on the base table 25. The drive motor 40 serves as a power source for rotating a rotating shaft 40a and moving the movable carriage 30. The rotating shaft 40a is rotatably supported by a pair of support bearings 40b.

[0046] Therefore, a first forward / backward movement process can be executed in which the movable carriage 30 is moved in the Y direction by the drive motor 40. At this time, the movable carriage 30 is guided by the pair of rails 51 and the multiple guides 55 so as to move accurately along the Y direction.

[0047] In conjunction with the movement of the movable carriage 30, the left / right movement mechanism 4B, the roller turning mechanism 3, the left / right movement mechanism 4T, the front / rear movement mechanism 5T and the roller drive mechanism 8, which are arranged on the movable carriage 30, move along the Y direction.

[0048] Therefore, the longitudinal movement mechanism 5B of the chassis dynamometer 1 can move the entire roller device 2 along the Y direction by executing the first longitudinal movement process. Here, the Y direction corresponds to the longitudinal direction of the vehicle 60 placed on the roller device 2.

[0049] In this way, the longitudinal movement mechanism 5B executes a first longitudinal movement process that moves both the roller turning mechanism 3 and the roller pair 20 along the longitudinal direction. The first longitudinal movement process by the longitudinal movement mechanism 5B also serves as a movement process for wheelbase adjustment to fit the wheelbase of the vehicle 60 under test.

[0050] The left-right movement mechanism 4B is provided on the moving carriage 30 of the front-rear movement mechanism 5B. The left-right movement mechanism 4B, which is a first left-right movement mechanism, includes a drive motor 41, a rail 52, a guide 56 and a moving bed 31 as main components.

[0051] Fig. 4 is a top view of the BB cross section of Fig. 2 as viewed from above (+Z direction). As shown in Fig. 4, a pair of rails 52 are provided parallel to each other along the X direction on the movable carriage 30. A plurality of guides 56 (two guides 56 are shown in Fig. 4) are provided on each rail 52. As shown in Fig. 2, a movable bed 31, which is a first bed for moving in the left-right direction, is fixed to the upper surface of each guide 56.

[0052] 2 and 4, a drive motor 41, which is a first left-right motor, is provided on the movable cart 30. The drive motor 41 serves as a power source for rotating a rotating shaft 41a and moving the movable bed 31. The rotating shaft 41a is rotatably supported by a pair of support bearings 41b.

[0053] Therefore, the left-right movement mechanism 4B, which is the first left-right movement mechanism, can execute a first left-right movement process for moving the moving bed 31 in the X direction by the drive motor 41. At this time, the moving bed 31 is guided by the pair of rails 52 and the multiple guides 56 so as to move accurately along the X direction.

[0054] In conjunction with the movement of the moving bed 31, which is the first left-right moving bed, the roller turning mechanism 3, the left-right moving mechanism 4T, the front-back moving mechanism 5T and the roller drive mechanism 8, which are arranged on the moving bed 31, move along the X direction.

[0055] Therefore, the chassis dynamometer 1 can move the components of the roller device 2 above the left-right movement mechanism 4B along the X direction (left-right direction) by causing the left-right movement mechanism 4B to execute a first left-right movement process.

[0056] When the first left-right movement process is executed by the left-right movement mechanism 4B, the front-rear movement mechanism 5B does not move left-right because the front-rear movement mechanism 5B is not linked to the movement of the moving bed 31.

[0057] In this way, the left / right movement mechanism 4B executes a first left / right movement process in which the drive motor 41, which is the first left / right movement bed, is moved along the X direction by the moving bed 31.

[0058] Here, the X direction corresponds to the left-right direction of the vehicle 60 on which the tire 6 is placed on the roller 10 of the roller device 2. Therefore, the left-right movement mechanism 4B executes a first left-right movement process that moves both the roller turning mechanism 3 and the roller pair 20 in the left-right direction.

[0059] The roller turning mechanism 3 is provided on the moving bed 31. The roller turning mechanism 3 includes a turning bed 32, a turning motor 42, and a turning bearing 38 as main components.

[0060] The swivel motor 42 is a geared motor whose speed can be controlled. A gear is attached to the tip of the swivel motor 42, and this gear meshes with a gear (not shown) attached to the outer periphery of the swivel bed 32. Therefore, the swivel bed 32 can be rotated by the rotation of the swivel motor 42.

[0061] The swivel bearing 38 rotatably supports the swivel bed 32, and the swivel bed 32 is rotated by the power of the swivel motor 42 around the center of the swivel bearing 38. In this manner, the roller swivel mechanism 3 has the swivel bed 32 that is rotated by the swivel motor 42.

[0062] In conjunction with the rotation of the swivel bed 32 in the roller turning mechanism 3, the left-right movement mechanism 4T, the front-rear movement mechanism 5T and the roller drive mechanism 8 above the roller turning mechanism 3 also turn.

[0063] The center of the cavity of the swivel bearing 38 becomes the roller pivot center C2 of the roller pair 20. Therefore, the roller pivoting mechanism 3 can perform a roller pivoting operation for pivoting the roller pair 20.

[0064] A left-right movement mechanism 4T, which is a second left-right movement mechanism, is provided on the turning bed 32 of the roller turning mechanism 3. The left-right movement mechanism 4T includes a drive motor 43, a rail 53, a guide 57, and a moving bed 33 as main components.

[0065] Fig. 5 is a top view of the CC cross section of Fig. 2 viewed from above (+Z direction). As shown in Fig. 5, a pair of rails 53 are provided parallel to each other along the X direction on the swivel bed 32. A plurality of guides 57 (two guides 57 are shown in Fig. 5) are provided on each rail 53. As shown in Fig. 2, a moving bed 33, which is a first moving bed, is fixed to the upper surface of each guide 57.

[0066] 2 and 5, a drive motor 43, which is a first moving motor, is provided on the swivel bed 32. The drive motor 43 serves as a power source for rotating a rotating shaft 43a and moving the moving bed 33. The rotating shaft 43a is rotatably supported by a pair of support bearings 43b.

[0067] Therefore, the left-right movement mechanism 4T can execute a second left-right movement process in which the moving bed 33 is moved in the X direction by the drive motor 43. At this time, the moving bed 33 is guided by the pair of rails 53 and the multiple guides 57 so as to move accurately along the X direction.

[0068] In conjunction with the movement of the moving bed 33, the front-rear direction moving mechanism 5T and the roller driving mechanism 8 arranged on the moving bed 33 move along the X direction.

[0069] Therefore, by executing the second left-right movement process, the left-right movement mechanism 4T of the chassis dynamometer 1 can move the components of the roller device 2 located above the left-right movement mechanism 4B along the X direction (left-right direction).

[0070] When the second left-right movement process is executed by the left-right movement mechanism 4T, the roller turning mechanism 3 located below the left-right movement mechanism 4T does not move left-right. This is because the roller turning mechanism 3 is not linked to the movement of the moving bed 33.

[0071] In this way, the left-right movement mechanism 4T executes a second left-right movement process in which the moving bed 33, which is the second left-right movement bed, is moved along the X direction by the drive motor 43, which is the second left-right motor. That is, the left-right movement mechanism 4T executes a second left-right movement process in which only the roller pair 20, out of the roller turning mechanism 3 and the roller pair 20, is moved along the left-right direction.

[0072] A front-rear movement mechanism 5T, which is a second front-rear movement mechanism, is provided on the moving bed 33 of the left-right movement mechanism 4T. The front-rear movement mechanism 5T includes a drive motor 44, a rail 54, a guide 58, and a moving bed 34 as main components.

[0073] Fig. 6 is a top view of the DD cross section of Fig. 2 as viewed from above (+Z direction). As shown in Fig. 6, a pair of rails 54 are provided parallel to each other along the Y direction on the moving bed 33. A plurality of guides 58 (two guides 58 are shown in Fig. 6) are provided on each rail 54. As shown in Fig. 2, the moving bed 34, which serves as the second front-rear moving bed, is fixed to the upper surface of each guide 58.

[0074] 2 and 6, a drive motor 44, which is a second forward / rearward motor, is provided on the moving bed 33. The drive motor 44 rotates a rotating shaft 44a, and serves as a power source for moving the moving bed 34. The rotating shaft 44a is rotatably supported by a pair of support bearings 44b.

[0075] Therefore, a second front-rear movement process can be executed in which the moving bed 34 is moved in the Y direction by the drive motor 44. At this time, the moving bed 34 is guided by the pair of rails 54 and the multiple guides 58 so as to move accurately along the Y direction.

[0076] In conjunction with the movement of the moving bed 34, the roller drive mechanism 8 provided on the moving bed 34 moves along the Y direction.

[0077] Therefore, the front-rear movement mechanism 5T of the chassis dynamometer 1 can move the roller pairs 20 of each roller device 2 along the Y direction by executing the second front-rear movement process.

[0078] When the second forward / backward movement process is executed by the forward / backward movement mechanism 5T, the roller turning mechanism 3 located below the forward / backward movement mechanism 5T does not move in the forward / backward direction. This is because the roller turning mechanism 3 is not linked to the movement of the moving bed 34.

[0079] In this manner, the front-rear direction moving mechanism 5T, which is the second front-rear direction moving mechanism, executes a second front-rear direction moving process to move the moving bed 34, which is the second front-rear direction moving bed, in the Y direction by the drive motor 44, which is the second front-rear direction motor. That is, the front-rear direction moving mechanism 5T executes a second front-rear direction moving process to move only the roller pair 20, out of the roller turning mechanism 3 and the roller pair 20, along the front-rear direction.

[0080] The combination of the left-right direction movement mechanisms 4B and 4T and the front-rear direction movement mechanisms 5B and 5T described above constitutes the position change mechanism MV. The position change mechanism MV executes a position change process for changing the position of the roller turning mechanism 3 with respect to the tire turning center C6 of the tire 6 placed on the roller pair 20.

[0081] The left-right movement mechanism 4B executes a first left-right movement process for moving both the roller pair 20 and the roller turning mechanism 3 along the left-right direction (X direction). The left-right movement mechanism 4T executes a first left-right movement process for moving only the roller pair 20 of the roller turning mechanism 3 and the roller pair 20 along the left-right direction.

[0082] The front-rear movement mechanism 5B executes a first front-rear movement process for moving both the roller pair 20 and the roller turning mechanism 3 along the front-rear direction (Y direction). The front-rear movement mechanism 5T executes a second left-right movement process for moving only the roller pair 20 of the roller turning mechanism 3 and the roller pair 20 along the front-rear direction (Y direction).

[0083] The position changing process by the position changing mechanism MV is a combination of the above-mentioned first and second left-right movement processes and first and second front-rear movement processes.

[0084] The roller drive mechanism 8 having the roller pair 20 is provided on the moving bed 34 of the front-rear moving mechanism 5T.

[0085] The roller drive mechanism 8 for the twin roller configuration includes as its main components a dynamo 11, a coupling 15, a gear box 26, a roller bearing 27, a pair of rollers 20, and a rotating shaft 28. Here, the rotating shaft 28 becomes a pair of rotating shafts 28, and the roller bearing 27 becomes a pair of roller bearings 27 corresponding to the pair of rotating shafts 28.

[0086] The dynamo 11 and the gear box 26 are fixed onto the moving bed 34, and the pair of rotating shafts 28 are rotated and driven from the dynamo 11, which serves as the driving source, via the coupling 15 and the gear box 26. Specifically, the rotational motion transmission function is branched into two within the gear box 26, enabling the pair of rotating shafts 28 to be rotated and driven.

[0087] A pair of roller bearings 27 are provided on the moving bed 34 so as to straddle the dynamo 11. A pair of rotating shafts 28 are supported between the gear box 26 and the pair of roller bearings 27 so that the roller pair 20 can rotate.

[0088] A pair of rotary shafts 28 are attached so as to penetrate the center of each roller pair 20, so that the roller pair 20 can perform a rotational motion in response to the rotation of the pair of rotary shafts 28.

[0089] Therefore, the roller driving mechanism 8 performs a roller driving operation to rotate the front roller 20F, which is a first roller. The roller driving mechanism 8 can also perform a roller driving operation to rotate the rear roller 20R, which is a second roller.

[0090] It should be noted that a twin roller configuration may be formed by providing two roller drive mechanisms 8 compatible with a single roller configuration on the moving bed 34.

[0091] Fig. 7 is an explanatory diagram showing a typical planar arrangement of roller device 2L and roller device 2R. Fig. 8 is an explanatory diagram showing a typical side arrangement of roller device 2R. Fig. 9 is an explanatory diagram showing a typical cross-sectional structure in cross section EE of Fig. 7. Fig. 10 is an explanatory diagram showing a typical cross-sectional structure in cross section FF of Fig. 7. An XYZ orthogonal coordinate system is shown in each of Figs. 7 to 10.

[0092] The roller device 2 of this embodiment is a device on which a pair of tires, either at the front or rear of a vehicle 60, is placed, and the pair of tires includes a left tire 6L and a right tire 6R.

[0093] The roller device 2 of the present embodiment has a roller pair 20 that is a combination of a front roller 20F that is a first roller and a rear roller 20R that is a second roller.

[0094] As shown in FIG. 7, the roller device 2 includes a roller device 2L as a left roller device provided corresponding to the tire 6L of the vehicle 60, and a roller device 2R as a right roller device provided corresponding to the tire 6R of the vehicle 60.

[0095] The roller device 2L and the roller device 2R can perform a roller turning operation to turn the front roller 20F and the rear roller 20R along the roller turning direction R2 by the roller turning mechanism 3 described above.

[0096] The roller devices 2L and 2R each have a position changing mechanism MV. The position changing mechanisms MV of the roller devices 2L and 2R simultaneously perform position changing processing.

[0097] As shown in Figures 7 and 8, the tire 6R (6L) is placed on the front roller 20F and the rear roller 20R, respectively. Note that Figures 7 and 8 show the front roller 20F and the rear roller 20R in contact with each other, since they are schematic representations of the roller pair 20. In reality, there is a very small space between the front roller 20F and the rear roller 20R, and the front roller 20F and the rear roller 20R are not in contact with each other.

[0098] 9, a rotation detector 81L is provided near the shaft end of the rotating shaft 28 of the front roller 20F of the roller device 2L. The rotation detector 81L detects the rotation speed of the front roller 20F in the roller device 2L to obtain a detected speed V1L.

[0099] Similarly, a rotation detector 81R is provided near the shaft end of the rotating shaft 28 of the front roller 20F of the roller device 2R. The rotation detector 81R detects the rotation speed of the front roller 20F in the roller device 2R to obtain a detected speed V1R.

[0100] In addition, since the front roller 20F is used as a load roller, the rotation detectors 81L and 81R may be set to the dynamo 11 which is the motor that is the power source of the front roller 20F.

[0101] The detected speed V1L obtained from the rotation detector 81L becomes a first detected speed for the left, and the detected speed V1R obtained from the rotation detector 81R becomes a first detected speed for the right.

[0102] In this way, the roller device 2 including the roller devices 2L and 2R includes the rotation detectors 81L and 81R as first rotation detectors, and the detected speeds V1L and V1R detected by the rotation detectors 81L and 81R become the first detected speeds.

[0103] Hereinafter, when the rotation detectors 81L and 81R are collectively referred to, they may be simply referred to as "rotation detector 81", and when the detected speeds V1L and V1R are collectively referred to, they may be simply referred to as "detected speed V1".

[0104] 10, a rotation detector 82L is provided near the shaft end of the rotating shaft 28 of the rear roller 20R of the roller device 2L. The rotation detector 82L detects the rotation speed of the rear roller 20R in the roller device 2L to obtain a detected speed V2L.

[0105] Similarly, a rotation detector 82R is provided near the shaft end of the rotating shaft 28 of the rear roller 20R of the roller device 2R. The rotation detector 82R detects the rotation speed of the rear roller 20R in the roller device 2R to obtain a detected speed V2R.

[0106] The detected speed V2L obtained from the rotation detector 82L becomes a second detected speed for the left, and the detected speed V2R obtained from the rotation detector 82R becomes a second detected speed for the right.

[0107] In this way, the roller device 2 including the roller devices 2L and 2R includes the rotation detectors 82L and 82R as second rotation detectors, and the detection speeds V2L and V2R detected by the rotation detectors 82L and 82R become the second detection speeds.

[0108] Hereinafter, when the rotation detectors 82L and 82R are collectively referred to, they may simply be referred to as "rotation detector 82", and when the detected speeds V2L and V2R are collectively referred to, they may simply be referred to as "detected speed V2".

[0109] Figure 11 is an explanatory diagram showing a schematic diagram of the control system of the roller device 2. The chassis dynamometer 1 of this embodiment has as its main components the roller device 2 and a control unit 80. In Figure 11, the roller turning mechanism 3, position changing mechanism MV, roller drive mechanism 8, and rotation detectors 81 and 82 in the roller device 2 are shown as blocks.

[0110] As shown in the figure, the control unit 80 receives detected speeds V1 and V2 obtained from rotation detectors 81 and 82, and controls the roller turning mechanism 3, position change mechanism MV and front roller 20F to perform roller turning operation, position change processing and roller driving operation.

[0111] Specifically, the control unit 80 causes the roller turning mechanism 3 to perform a roller turning operation by supplying a drive signal SD3 to the roller turning mechanism 3, and causes the position changing mechanism MV to perform a position changing process by supplying a drive signal SDP to the position changing mechanism MV.

[0112] Furthermore, the control unit 80 can provide a drive signal SD8 to the roller drive mechanism 8 to cause the roller drive mechanism 8 to execute a roller drive operation for rotating the front roller 20F.

[0113] In the roller device 2 of this embodiment, the front roller 20F is used as a load roller that rotates by itself. On the other hand, the rear roller 20R is used as a free roller that rotates in conjunction with the rotation of the tire 6 that it contacts. Therefore, the drive signal SD8 does not instruct the rear roller 20R to rotate, so the control unit 80 separates the rear roller 20R from the dynamo 11.

[0114] The front roller 20F and the rear roller 20R can be used as either a road roller or a free roller. A road roller is a roller that rotates by itself when driven by the dynamo 11, which serves as a motor, and a free roller is a roller that is separated from the dynamo 11 and rotates according to the rotation of the tire 6.

[0115] In this manner, in the chassis dynamometer 1 of this embodiment, the front rollers 20F are used as load rollers, and the rear rollers 20R are used as free rollers.

[0116] (Method of moving the roller turning mechanism 3) 12 is a flowchart showing the processing steps of the method of moving the roller turning mechanism 3 using the chassis dynamometer 1 according to the embodiment. Hereinafter, the processing contents of the method of moving the roller turning mechanism 3 will be described with reference to the same drawing.

[0117] In the following, a description will be given under the assumption that a pair of tires 6 on the front wheel side of the vehicle 60 performs a tire turning motion due to a steering operation.

[0118] In addition, as described above, the left side of the pair of tires 6 on the front wheel side of the vehicle 60 will be referred to as tire 6L and the right side as tire 6R, and the roller device 2 for tire 6L will be referred to as roller device 2L, and the roller device 2 for tire 6R will be referred to as roller device 2R. Here, roller device 2L is the left roller device, and roller device 2R is the right roller device.

[0119] Furthermore, the center of rotation of tire 6L is the left tire center of rotation C6L, the center of rotation of tire 6R is the right tire center of rotation C6R, the center of rotation of roller pair 20 in roller device 2L is the left roller center of rotation C2L, and the center of rotation of roller pair 20 in roller device 2R is the right roller center of rotation C2R.

[0120] Furthermore, when the method for moving the roller turning mechanism 3 is executed, a plurality of set positions are prepared in advance as candidate movement positions for the roller turning mechanism 3.

[0121] 12, first, in step S1, the roller turning center C2 of the roller turning mechanism 3 is set to an initial setting position included in the above-mentioned plurality of setting positions.

[0122] When step S1 is performed, since no vehicle 60 is placed on the roller devices 2L and 2R, the roller devices 2L and 2R, each including the roller turning mechanism 3, can be moved manually to place the roller turning mechanism 3 in the initial setting position. Note that, even when step S1 is performed, the position change mechanism MV may be caused to execute a position change process to set the roller turning mechanism 3 to the initial setting position.

[0123] Then, in step S2, the four tires 6 of the vehicle 60 are placed on the four roller pairs 20. Of the four roller pairs 20, at least two roller pairs 20 for the front wheels are provided in the roller device 2 shown in Figs. 2 to 6, and a part of the upper part is exposed from the floor surface 50. By performing step S2, the vehicle 60 is placed so as to be symmetrical with respect to the center line CL between the left and right roller devices 2L and 2R.

[0124] Furthermore, in step S2, the vehicle 60 arranged on the four roller pairs 20 is fixed so that the turning center setting process in step S3 and thereafter can be performed. The vehicle 60 arranged on the roller pairs 20 is fixed using an existing vehicle fixing mechanism.

[0125] In this way, by executing steps S1 and S2, the roller turning mechanism 3 is set to an initial setting position included in a plurality of setting positions, and a state in which the tire 6 of the vehicle 60 is placed and fixed on the roller pair 20 is set.

[0126] In the following, it is assumed that, of the four roller pairs 20, the two roller pairs 20 for the front wheels are provided in the roller device 2 shown in FIGS.

[0127] In the subsequent steps S3 to S7, a turning center setting process is executed under the control of the control unit 80.

[0128] First, in step S3, the control unit 80 applies a drive signal SD3 to the roller turning mechanism 3, and also applies a drive signal SD8 to the roller drive mechanism 8 in the roller device 2 for the front wheels, thereby executing the road roller acceleration / deceleration process.

[0129] Here, the drive signal SD3 is a signal for setting the roller turning mechanism 3 in a predetermined turning direction, and the drive signal SD8 is a signal for instructing the front roller 20F to be rotated but not for instructing the rear roller 20R to be rotated.

[0130] Therefore, in step S3, by executing a roller rotation operation by the roller rotation mechanism 3 and a roller drive operation by the roller drive mechanism 8, the roller pair 20 is set in a predetermined rotation direction, and a test environment is created in which the first roller, the front roller 20F, is rotated in a manner that accelerates and decelerates the rotational speed.

[0131] The road roller acceleration / deceleration process in step S3 is a process in which a temporary running test of the vehicle 60 is performed in the above test environment, and the rotation detectors 81 and 82 obtain the first and second detected speeds V1 and V2.

[0132] In this way, step S3 is a step in which roller rotation operation and roller drive operation are executed, and with the roller pair 20 set in a predetermined rotation direction, a temporary running test of the vehicle 60 is performed by rotating the front roller 20F in a manner that accelerates and decelerates the rotational speed, thereby obtaining detection speeds V1 and V2.

[0133] Fig. 13 is a flowchart showing the process content of step S3 shown in Fig. 12. As shown in the figure, step S3 includes steps S31 to S33.

[0134] 13, in step S31, a straight-line acceleration / deceleration process is executed. That is, in step S31, with the roller pair 20 set in the straight-line direction, the front roller 20F is rotated in a manner that accelerates and decelerates the rotational speed, and a straight-line running test is performed on the vehicle 60. The detected speeds V1 and V2 obtained from the rotation detectors 81 and 82 when step S31 is executed become straight-line detection speeds V11 and V21.

[0135] Here, the straight-traveling detected speed V11 is the first straight-traveling detected speed, and the straight-traveling detected speed V21 is the second straight-traveling detected speed.

[0136] Further, the straight-travel detection speeds V11 and V21 are obtained from the roller devices 2L and 2R, respectively. The straight-travel detection speeds V11 and V21 obtained from the roller device 2L become the straight-travel detection speeds V11L and V21L, and the straight-travel detection speeds V11 and V21 obtained from the roller device 2R become the straight-travel detection speeds V11R and V21R.

[0137] Next, in step S32, left-turn acceleration / deceleration processing is executed. That is, in step S32, with the roller pair 20 set in the left-turn direction, the front roller 20F is rotated in a manner that accelerates and decelerates the rotation speed, and a left-turn running test is performed on the vehicle 60. The detected speeds V1 and V2 obtained from the rotation detectors 81 and 82 during execution of step S32 become the detected speeds V12 and V22 during left turning.

[0138] Here, the left turning detection speed V12 is the first left turning detection speed, and the left turning detection speed V22 is the second left turning detection speed. The left turning direction is a direction turned leftward by a predetermined angle from the straight ahead direction. The left turning direction may be set to a plurality of angles.

[0139] Furthermore, the left turning detection speeds V12 and V22 are obtained from the roller devices 2L and 2R, respectively. The left turning detection speeds V12 and V22 obtained from the roller device 2L become the left turning detection speeds V12L and V22L, and the left turning detection speeds V12 and V22 obtained from the roller device 2R become the left turning detection speeds V12R and V22R.

[0140] Then, in step S33, right turn acceleration / deceleration processing is executed. That is, in step S33, with the roller pair 20 set in the right turn direction, the front roller 20F is rotated in a manner that accelerates and decelerates the rotation speed, and a right turn running test is performed on the vehicle 60. The detected speeds V1 and V2 obtained from the rotation detectors 81 and 82 during execution of step S33 become the detected speeds V13 and V23 during right turn.

[0141] Here, the right turning detection speed V13 is the first right turning detection speed, and the right turning detection speed V23 is the second right turning detection speed. The right turning direction is a direction turned to the right by a predetermined angle from the straight ahead direction. The right turning direction may be set to multiple angles.

[0142] Further, the detected speeds V13 and V23 during a right turn are obtained from the roller devices 2L and 2R, respectively. The detected speeds V13 and V23 during a right turn obtained from the roller device 2L become the detected speeds V13L and V23L during a right turn, and the detected speeds V13 and V23 during a right turn obtained from the roller device 2R become the detected speeds V13R and V23R during a right turn.

[0143] Here, the detection speed V11L when traveling straight, the detection speed V12L when turning left, and the detection speed V13L when turning right are classified as first detection speeds for the left, and the detection speed V11R when traveling straight, the detection speed V12R when turning left, and the detection speed V13R when turning right are classified as first detection speeds for the right.

[0144] Similarly, the detection speed V21L when traveling straight, the detection speed V22L when turning left, and the detection speed V23L when turning right are classified as second detection speeds for the left, and the detection speed V21R when traveling straight, the detection speed V22R when turning left, and the detection speed V23R when turning right are classified as second detection speeds for the right.

[0145] In steps S31 to S33 shown in FIG. 13, the above-mentioned straight direction, right turning direction, and right turning direction are set as the predetermined turning directions, and as temporary driving tests, a straight driving test in step S31, a left turning driving test in step S32, and the right turning driving test in step S33 are performed.

[0146] The straight-ahead test, left-turn running test, and right-turn running test are performed under an operating environment in which the rotation speed of the front roller 20F is accelerated and decelerated.

[0147] Therefore, during the execution of step S3, the straight ahead detection speed V11 (V11L, V11R), the left turning detection speed V12 (V12L, V12R), and the right turning detection speed V13 (V13L, V13R) are detected as the first detected speed V1.

[0148] Furthermore, during execution of step S3, a straight ahead detection speed V21 (V21L, V21R), a left turning detection speed V22 (V22L, V22R), and a right turning detection speed V23 (V23L, V23R) are detected as the second detected speed V2.

[0149] In this way, during the execution of step S3, it is possible to detect the detected speeds V1 (V11 to V13) and V2 (V21 to V23) at one of the multiple set positions of the roller rotation center C2. Note that during the execution of step S3, the detected speeds V1 and V2 are detected every moment during the detection periods of the rotation detectors 81 and 82.

[0150] 12, after execution of step S3, in step S4, the control unit 80 gives a drive signal SDP to the position change mechanism MV, thereby causing the position change mechanism MV to execute a position change process for the roller turning mechanism 3. The position change process is a process for changing the position of the roller turning mechanism 3 without moving the vehicle 60 (including the tire turning center C6).

[0151] That is, step S4 is a step of causing the position change mechanism MV to execute a position change process and changing the position of the roller turning mechanism 3 to a new set position included in the plurality of set positions. As the position of the roller turning mechanism 3 is changed, the roller turning center C2 is also changed.

[0152] Fig. 14 is a flow chart showing the contents of the position change process in step S4 shown in Fig. 12. The contents of the position change process will be described below with reference to the drawing.

[0153] First, in step S4A, the control unit 80 controls the roller turning mechanism 3 and the roller drive mechanism 8 to rotate the front roller 20F at a constant rotational speed with the roller pair 20 set in a straight line direction. At this time, the control unit 80 provides a drive signal SD3 to the roller turning mechanism 3, and a drive signal SD8 to the roller drive mechanism 8 in the roller device 2 for the front wheels.

[0154] Here, the drive signal SD3 is a signal for setting the roller turning mechanism 3 in a straight direction, and the drive signal SD8 is a signal for instructing the front roller 20F in the roller device 2 for the front wheels to be rotated at a constant rotation speed.

[0155] In this manner, step S4A is a step in which the roller turning operation and the roller driving operation are executed, and the front roller 20F is rotated at a constant speed in a state in which the roller pair 20 is set in a straight direction.

[0156] Then, in step S4B, under the roller rotation environment set in step S4A, the position change mechanism MV executes a position change process to change the position of the roller turning mechanism 3 to a new setting position among the multiple setting positions. As the position of the roller turning mechanism 3 is changed, the position of the roller turning center C2 is also changed.

[0157] That is, step S4B is a step of causing the position change mechanism MV to execute a position change process under the roller rotation environment set in step S4A to change the position of the roller turning mechanism 3 to a new set position.

[0158] Fig. 15 is a flow chart showing the processing contents of the position change processing shown in step S4B shown in Fig. 14. As shown in the figure, step S4B executes a left-right direction movement routine SLR, and then executes a front-back direction movement routine SFB. Note that the front-back direction movement routine SFB may be executed first, and the left-right direction movement routine SLR may be executed later.

[0159] Fig. 16 is an explanatory diagram showing the execution contents of the left-right movement routine SLR shown in Fig. 15. Figs. 17 and 18 are explanatory diagrams showing the state of the roller devices 2L and 2R when the left-right movement routine SLR is executed. Fig. 17 shows the state at the start of execution of the left-right movement routine SLR, and Fig. 18 shows the state at the end of execution of the left-right movement routine SLR. Note that XYZ orthogonal coordinate systems are shown in Figs. 17 and 18.

[0160] The processing contents of the left-right direction movement routine SLR will be explained below with reference to these figures. The multiple set positions are specified by the coordinate position of the roller pivot center C2. Here, for the roller pivot center C2 (C2L, C2R), the absolute value of the movement amount in the X direction to change from the current set position P0 to the new set position P1 is |ΔX1|, and the absolute value of the movement amount in the Y direction is |ΔY1|.

[0161] Also shown in FIG. 17 are the initial leftmost edge line EL0 of the roller device 2L and the initial rightmost edge line ER0 of the roller device 2R.

[0162] As described above, when step S2 is performed, the vehicle 60 is placed so as to be symmetrical with respect to the center line CL between the roller devices 2L and 2R, so that the absolute values ​​of the movement amounts in the left-right direction (X direction) are the same and the movement directions are opposite.

[0163] Here, it is assumed that the set positions P0 and P1 are set with respect to the roller device 2L. In other words, it is assumed that the set positions P0 and P1 indicate the coordinate position of the left roller turning center C2L. Therefore, as shown in Fig. 17, when the left roller turning center C2L is moved in the +X direction by a movement amount |ΔX1| as a movement process of the roller turning mechanism 3 in the X direction from the set position P0 to the set position P1, the right roller turning center C2R is moved in the -X direction by a movement amount |ΔX1|.

[0164] In the above case, the following steps S41 to S44 are executed in parallel as the left-right movement routine SLR. That is, the roller devices 2L and 2R simultaneously execute the first and second left-right movement processes included in the position change process.

[0165] In step S41, the roller turning mechanism 3 and the roller pair 20 are both moved in the +X direction by a first left-right movement process (movement content +ΔX1) of the left-right movement mechanism 4B of the roller device 2L. Regarding the first left-right movement process of the roller device 2L executed in step S41, the first left-right movement direction is the +X direction, and the left-right movement amount is |ΔX1|.

[0166] In step S42, the roller turning mechanism 3 and the roller pair 20 are both moved in the -X direction by a first left-right movement process (movement content -ΔX1) of the left-right movement mechanism 4B of the roller device 2R. Here, for the first left-right movement process of the roller device 2R, the first left-right movement direction is the -X direction, and the left-right movement amount is |ΔX1|.

[0167] In step S43, the roller turning mechanism 3 and only the roller pair 20 of the roller pair 20 are moved in the -X direction by the second left-right movement process (movement content -ΔX1) of the left-right movement mechanism 4T of the roller device 2L. Here, for the second left-right movement process of the roller device 2L, the second left-right movement direction is the -X direction, and the left-right movement amount is |ΔX1|.

[0168] In step S44, the roller turning mechanism 3 and only the roller pair 20 of the roller pair 20 are moved in the +X direction by the second left-right movement process (movement content +ΔX1) of the left-right movement mechanism 4T of the roller device 2R. Here, with regard to the second left-right movement process of the roller device 2R, the second left-right movement direction becomes the +X direction, and the left-right movement amount becomes |ΔX1|.

[0169] The left and right movement speeds along the left and right direction (X direction) of the first left and right movement process by the left and right movement mechanism 4B of the roller device 2L, the first left and right movement process by the left and right movement mechanism 4B of the roller device 2R, the second left and right movement process by the left and right movement mechanism 4T of the roller device 2L, and the second left and right movement process by the left and right movement mechanism 4T of the roller device 2R, which are executed as steps S41 to S44 described above, are also set to be the same.

[0170] In each of the roller devices 2L and 2R, the first left / right movement process by the left / right movement mechanism 4B and the second left / right movement process by the left / right movement mechanism 4T are simultaneously executed with the same left / right movement amount (|ΔX1|).

[0171] Furthermore, in each of the roller devices 2L and 2R, the first and second left and right movement directions are set to be opposite to each other. Specifically, in the roller device 2L, the first left and right movement direction is the +X direction and the second left and right movement direction is the -X direction, while in the roller device 2R, the first left and right movement direction is the -X direction and the second left and right movement direction is the +X direction.

[0172] 17 and 18, the absolute positions of the roller pairs 20 of the roller devices 2L and 2R do not change before and after the first and second left-right movement processes are performed by the roller devices 2L and 2R, respectively. Therefore, in each of the roller devices 2L and 2R, the positional relationship between the roller pairs 20 and the tires 6 (6L, 6R) in the X direction also does not change.

[0173] 17 and 18, the parts whose absolute positions have moved after steps S41 to S44 are the main parts of the left-right movement mechanism 4B, the roller turning mechanism 3, and part of the left-right movement mechanism 4T, which are indicated by hatched areas. As a result, before and after steps S41 to S44, the initial leftmost end line EL0 changes to the processed leftmost end line EL1, and the initial rightmost end line ER0 changes to the processed rightmost end line ER1.

[0174] In this manner, the chassis dynamometer 1 of the present embodiment simultaneously executes the first and second left and right movement processes in the roller device 2L and the first and second left and right movement processes in the roller device 2R.

[0175] Therefore, the chassis dynamometer 1 of this embodiment can move the left roller turning center C2L in the +X direction by an amount |ΔX1| and move the right roller turning center C2R in the -X direction by an amount |ΔX1| without changing the positional relationship between the roller pair 20 and the tires 6. In other words, by executing the left-right direction movement routine SLR, the set position in the X direction of the roller turning mechanism 3 with respect to the tire turning center C6 (C6L, C6R) can be changed.

[0176] Fig. 19 is an explanatory diagram showing the execution contents of the forward / rearward movement routine SFB shown in Fig. 15. Figs. 20 and 21 are explanatory diagrams showing the state of the roller device 2 (2L, 2R) when the forward / rearward movement routine SFB is executed. Fig. 20 shows the state at the start of execution of the forward / rearward movement routine SFB, and Fig. 21 shows the state at the end of execution of the forward / rearward movement routine SFB. Note that XYZ orthogonal coordinate systems are shown in Figs. 20 and 21, respectively.

[0177] The processing contents of the forward / rearward movement routine SFB will be described below with reference to these figures. Here, it is assumed that the roller pivot mechanism 3 is moved by moving the roller pivot center C2 (C2L, C2R) in the +Y direction by a movement amount |ΔY1|.

[0178] In addition, when step S2 shown in Figure 12 is executed, the tires 6L and 6R of the vehicle 60 are placed on the roller pairs 20 of the roller devices 2L and 2R without any positional misalignment in the fore-and-aft direction, so the absolute value of the movement amount in the fore-and-aft direction (Y direction) between the left and right turning centers is the same, and the movement direction is also the same.

[0179] As described above, it is assumed that the set positions P0 and P1 are set with respect to the roller device 2L. That is, the set positions P0 and P1 indicate the coordinate position of the left roller pivot center C2L. Therefore, as shown in Fig. 20, movement of the roller pivot mechanism 3 in the Y direction from the set position P0 to the set position P1 is a process of moving the left roller pivot center C2L in the +Y direction by a movement amount |ΔY1|, and moving the right roller pivot center C2R in the +Y direction by a movement amount |ΔY1|.

[0180] In the above case, as shown in FIG. 19, the following steps S45 to S48 are executed in parallel at the same time as a forward / rearward movement routine SFB.

[0181] In step S45, the first forward / backward movement process (movement content +ΔY1) of the forward / backward movement mechanism 5B of the roller device 2L moves both the roller turning mechanism 3 and the roller pair 20 in the +Y direction. Here, with regard to the first forward / backward movement process of the roller device 2L, the first forward / backward movement direction is the +Y direction, and the forward / backward movement amount is |ΔY1|.

[0182] In step S46, the first forward / backward movement process (movement content +ΔY1) of the forward / backward movement mechanism 5B of the roller device 2R moves both the roller turning mechanism 3 and the roller pair 20 in the + direction. Here, for the first forward / backward movement process of the roller device 2R, the first forward / backward movement direction is the +Y direction, and the forward / backward movement amount is |ΔY1|.

[0183] In step S47, the second front-rear movement process (movement content -ΔY1) of the front-rear movement mechanism 5T of the roller device 2L moves only the roller pair 20 out of the roller turning mechanism 3 and the roller pair 20 in the -Y direction. Here, for the second front-rear movement process of the roller device 2L, the second front-rear movement direction becomes the -Y direction, and the front-rear movement amount becomes |ΔY1|.

[0184] In step S48, the second front-rear movement process (movement content -ΔY1) of the front-rear movement mechanism 5T of the roller device 2R moves only the roller pair 20 out of the roller turning mechanism 3 and the roller pair 20 in the -Y direction. Here, for the second front-rear movement process of the roller device 2R, the second front-rear movement direction becomes the -Y direction, and the front-rear movement amount becomes |ΔY1|.

[0185] The forward / backward movement speeds along the forward / backward direction (Y direction) of each of the first forward / backward movement process by the forward / backward movement mechanism 5B of the roller device 2L, the first forward / backward movement process by the forward / backward movement mechanism 5B of the roller device 2R, the second forward / backward movement process by the forward / backward movement mechanism 5T of the roller device 2L, and the second forward / backward movement process by the forward / backward movement mechanism 5T of the roller device 2R, which are executed as steps S45 to S48 described above, are also set to be the same.

[0186] In each of the roller devices 2L and 2R, the first forward / backward movement process by the forward / backward movement mechanism 5B and the second forward / backward movement process by the forward / backward movement mechanism 5T are simultaneously performed with the same forward / backward movement amount (|ΔY1|).

[0187] Furthermore, in each of the roller devices 2L and 2R, the first front-rear movement direction and the second front-rear movement direction are set in opposite directions. Specifically, in each of the roller devices 2L and 2R, the first left-right movement direction is the +Y direction, and the second left-right movement direction is the -Y direction.

[0188] 20 and 21, the absolute positions of the roller pairs 20 of the roller devices 2L and 2R do not change before and after the first and second forward / rearward movement processes are performed by the roller devices 2L and 2R, respectively. Therefore, the positional relationship between the roller pairs 20 and the tires 6 (6L, 6R) in the Y direction does not change in the roller devices 2L and 2R, respectively.

[0189] As shown in Figures 20 and 21, after steps S41 to S44 are executed, the absolute positions of part of the forward / rearward movement mechanism 5B, the left / right movement mechanism 4B, the roller turning mechanism 3, the left / right movement mechanism 4T, and part of the forward / rearward movement mechanism 5T, which are indicated by hatched areas, have moved.

[0190] As described above, the chassis dynamometer 1 of the present embodiment simultaneously executes the first and second front-rear direction movement processes in the roller device 2L and the first and second front-rear direction movement processes in the roller device 2R.

[0191] Therefore, the chassis dynamometer 1 of this embodiment can move the left roller turning centers C2L and C2R in the +Y direction by a movement amount |ΔY1| relative to the tire turning center C6 in the fore-and-aft direction without changing the positional relationship between the roller pairs 20 and the tire 6. In other words, by executing the fore-and-aft direction movement routine SFB, the set position in the Y direction of the roller turning mechanism 3 relative to the tire turning center C6 (C6L, C6R) can be changed.

[0192] Since the chassis dynamometer 1 of this embodiment has a position change mechanism MV including left-right moving mechanisms 4B and 4T and forward-backward moving mechanisms 5B and 5T, it is possible to execute the position change process of the roller turning mechanism 3 described above (see step S4 in Figure 12, Figures 14, 15, and 19).

[0193] Therefore, the chassis dynamometer 1 of this embodiment can change the position of the roller turning mechanism 3 with respect to the tire turning center C6 with the tire 6 placed on the roller pair 20. By changing the position of the roller turning mechanism 3, the position of the roller turning center C2 with respect to the tire turning center C6 can also be changed.

[0194] FIG. 22 is an explanatory diagram showing, in a table format, an example of the coordinates of a plurality of set positions that are targets of the position change process in step S4 shown in FIG. 12 and a processing procedure.

[0195] As shown in the figure, the coordinates of the setting values ​​are indicated by (Xi (i = 1 to n), Yj (j = 1 to n)). The X coordinate Xi indicates the coordinate in the X direction, which is the left-right direction of the vehicle 60. The Y coordinate Yj indicates the coordinate in the Y direction, which is the front-rear direction (straight-ahead direction) of the vehicle 60. As described above, the coordinates of each of the multiple setting positions are set with respect to the roller pivot center C2 (C2L) of the roller pivot mechanism 3.

[0196] In the example shown in Fig. 22, (n x n) set positions are shown as the multiple set positions. The coordinates (X1, Y1) are the initial setting position in step S1, and the coordinates (X2, Y1) are the set position set in the initial position change process in step S4. The multiple set positions are prepared in advance in a manner that allows a predetermined number of set positions to be set at intervals of several tens of mm in the positive and negative directions of the X and Y coordinates with respect to the tread position described in a catalog or the like of the vehicle 60.

[0197] In the subsequent position change process in step S4, the set position of the roller turning mechanism 3 is changed in the order of coordinates (X3, Y1), ..., (Xn, Y1), (X1, Y2), (X2, Y2), ..., (Xn, Y2), (X1, Y3), (X2, Y3), ..., (Xn, Yn).

[0198] For convenience of explanation, the procedure of the position change process in step S4 will be described below using an example in which n = 3. In this case, steps (1) to (9) are executed in this order, as shown by the circled numbers in FIG.

[0199] That is, the coordinates (X1, Y1) of process (1) become the initial setting position of step S1, and the coordinates (X2, Y1) of process (2) become the setting position set in the position change process of the first step S4.

[0200] In processes (3) to (9) in the position change process of subsequent step S4, the setting position of the roller rotation center C2 is changed in the order of coordinates (X3, Y1), (X1, Y2), (X2, Y2), (X3, Y2), (X1, Y3), (X2, Y3), (X3, Y3).

[0201] When executing process (4), the movement amount |ΔX1| is |X1 - X3|, the movement direction when X1 > X3 is the +X direction, and the movement direction when X1 < X3 is the +X direction. Similarly, the movement amount |ΔY1| is |Y2 - Y1|, the movement direction when Y2 > Y1 is the +Y direction, and the movement direction when Y2 < Y1 is the +Y direction.

[0202] In processes (2), (3), (5), (6), (8) and (9), since the Y coordinate does not change, the movement amount |ΔY1| becomes "0", the execution of the forward and backward movement routine SFB is omitted, and the processing content of step S4B can be simplified.

[0203] Returning to FIG. 12, in step S5, it is confirmed whether (YES) or not (NO) the load roller acceleration / deceleration process of step S3 has ended at all of the plurality of setting positions. Therefore, when a change to a new setting position is made in step S4, step S5 becomes "NO".

[0204] Thereafter, steps S3 and S4 are repeatedly executed until "YES" is determined in step S5. Finally, when no change to a new setting position is made in step S4, step S5 becomes "YES".

[0205] For example, in the example shown in Fig. 22, after the position change process from coordinates (X(n-1), Yn) to coordinates (Xn, Yn) is performed, when step S4 is executed via steps S5 and S3, the load roller acceleration / deceleration process is performed for all of the multiple set positions. In this case, the change to a new set position is not performed in step S4, and step S5 becomes "YES".

[0206] In step S6, which is executed if the answer is YES in step S5, the control unit 80 determines the optimum setting position of the roller pivot center C2 in the roller pivot mechanism 3.

[0207] In this manner, step S5 is a step for repeatedly executing steps S3 and S4 until step S3 has been executed for all of the plurality of set positions.

[0208] FIG. 23 is a flowchart showing a first processing procedure of the optimum setting position determination processing shown in step S6 of FIG.

[0209] The control unit 80 obtains the detected velocities V1 and V2, which change from moment to moment, at each of the plurality of set positions while steps S31 to S33 are being executed.

[0210] When step S31 is executed, the control unit 80 acquires straight-ahead detection speeds V11 and V21 as the detected speeds V1 and V2. When step S32 is executed, the control unit 80 acquires left-turn detection speeds V12 and V22 as the detected speeds V1 and V2. When step S33 is executed, the control unit 80 acquires right-turn detection speeds V13 and V23 as the detected speeds V1 and V2.

[0211] Therefore, the control unit 80 can calculate the straight-traveling speed difference ΔV11 corresponding to the set position of the roller turning mechanism 3 based on the speed difference between the straight-traveling detected speeds V11 and V21 during the execution of step S31.

[0212] Here, various speed differences can be calculated as the straight-line speed difference ΔV11, such as the average speed difference (first type speed difference) between the straight-line detection speeds V11 and V21 during a specified period of time during acceleration, the average speed difference (second type speed difference) between the straight-line detection speeds V11 and V21 during a specified period of time during deceleration, and the average speed difference between the first type speed difference and the second type speed difference (third type speed difference).

[0213] Similarly, the control unit 80 can calculate the left turning speed difference ΔV12 corresponding to the set position of the roller turning mechanism 3 based on the speed difference between the left turning detected speeds V12 and V22 during the execution of step S32.

[0214] Furthermore, the control unit 80 can calculate the right turning speed difference ΔV13 corresponding to the set position of the roller turning mechanism 3 based on the speed difference between the right turning detected speeds V13 and V23 during the execution of step S33.

[0215] As the left turning speed difference ΔV12 and the right turning speed difference ΔV13, various speed differences such as the above-mentioned first to third speed differences can be calculated, similar to the straight-ahead speed difference ΔV11. Furthermore, a plurality of angles of the left turning direction and the right turning direction may be set, and the speed difference may be calculated for each different turning angle.

[0216] Furthermore, since the roller device 2 is composed of the roller devices 2L and 2R, as described above, the straight-ahead speed difference ΔV11, the left turning speed difference ΔV12, and the right turning speed difference ΔV13 are calculated for each of the roller devices 2L and 2R.

[0217] That is, for the roller device 2L, a speed difference ΔV11L when traveling straight, a speed difference ΔV12L when turning left, and a speed difference ΔV13L when turning right are calculated, and for the roller device 2R, a speed difference ΔV11R when traveling straight, a speed difference ΔV12R when turning left, and a speed difference ΔV13R when turning right are calculated.

[0218] In this manner, the control unit 80 can calculate six types of speed differences (ΔV11L, ΔV11R, ΔV12L, ΔV12R, ΔV13L, and ΔV13R) for each of the multiple set positions during the execution of step S3 (S31 to S33).

[0219] Therefore, when the execution of step S6 starts, the control unit 80 can calculate six different speed differences corresponding to the multiple set positions.

[0220] 24, in step S61, the control unit 80 calculates the speed difference sum SMV for each of the multiple set positions by applying the following formula (1). This speed difference sum SMV becomes the speed difference for judgment.

[0221] SMV=ΔV11L+ΔV12L+ΔV13L+ΔV11R+ΔV12R+ΔV13R…(1)

[0222] After step S61 is executed, a plurality of speed difference sums SMV corresponding to a plurality of set positions are calculated. For example, when the plurality of set positions is N set positions, N speed difference sums SMV are calculated.

[0223] Next, in step S62, the control unit 80 determines the setting position with the smallest speed difference sum SMV among the multiple setting positions as the optimal setting position. In other words, if the smallest speed difference sum SMV among the multiple speed difference sums SMV that are the multiple speed differences for determination is the minimum speed difference sum SMV(MIN), the setting position corresponding to the minimum speed difference sum SMV(MIN) among the multiple setting positions becomes the optimal setting position.

[0224] Fig. 24 is a flow chart showing a second processing procedure of the optimum set position determination processing shown in step S6 of Fig. 12. In this figure, the maximum speed difference MXV is calculated in step S63.

[0225] As described above, at the start of execution of step S6, the control unit 80 calculates the six types of speed differences (ΔV11L, ΔV11R, ΔV12L, ΔV12R, ΔV13L, and ΔV13R) that correspond to the multiple set positions, respectively.

[0226] In step S63, the control unit 80 calculates the maximum speed difference MXV for each of the multiple set positions by applying the following formula (2). This maximum speed difference MXV becomes the speed difference for judgment.

[0227] MXV=MAX(ΔV11L,ΔV12L,ΔV13L,ΔV11R,ΔV12R,ΔV13R)…(2) In equation (2), MAX(...) is a function in which the maximum value of the parameters in the parentheses is the maximum speed difference MXV.

[0228] After step S63 is executed, a plurality of maximum speed differences MXV corresponding to the plurality of set positions are calculated. For example, when the plurality of set positions is N set positions, N maximum speed differences MXV are calculated.

[0229] Next, in step S64, the control unit 80 determines the setting position where the maximum speed difference MXV is smallest among the multiple setting positions as the optimal setting position. In other words, if the smallest maximum speed difference MXV among the multiple maximum speed differences MXV that are the multiple speed differences for determination is set as the maximum speed difference minimum value MXV(MIN), the setting position corresponding to the maximum speed difference minimum value MXV(MIN) among the multiple setting positions becomes the optimal setting position.

[0230] In this way, the optimum setting position can be determined by executing step S6 including the first and second processing procedures shown in Figures 23 and 24. It is estimated that the optimum setting position of the roller turning mechanism 3 is the positional relationship where the tire turning center C6 and the roller turning center C2 are closest to each other, ideally the position where the tire turning center C6 and the roller turning center C2 coincide with each other.

[0231] Returning to FIG. 12, after the execution of step S6, in step S7, the position changing mechanism MV is made to execute a position changing process to move the roller turning mechanism 3 to its optimal setting position.

[0232] By executing step S7 under the control of the control unit 80, the roller turning mechanism 3 can be automatically moved so that the tire turning center C6 and the roller turning center C2 are in the closest positional relationship, and ideally, the roller turning center C2 coincides with the tire turning center C6.

[0233] Note that the process of step S7 is performed, for example, with the same content as steps S4A and S4B in FIG. 14. In step S6, when the coordinates (X3, Y3) are determined as the optimal setting position among the plurality of setting positions shown in FIG. 22, the movement amount |ΔX1| is |X3 - Xn|. When X3 > Xn, the movement direction is the +X direction, and when X3 < Xn, the movement direction is the -X direction. Similarly, the movement amount |ΔY1| is |Y3 - Yn|. When Y3 > Yn, the movement direction is the +Y direction, and when Y3 < Yn, the movement direction is the -Y direction.

[0234] (Effect) In the chassis dynamometer 1 which is the vehicle test apparatus of the present embodiment, by executing the turning center setting process including steps S3 to S7 in FIG. 12 under the control of the control unit 80, among the plurality of determination speed differences (speed difference sum SMV or maximum speed difference MXV), the roller turning mechanism 3 can be automatically arranged at the optimal setting position corresponding to the determination speed difference that becomes the minimum value.

[0235] Therefore, the chassis dynamometer 1 of the present embodiment can automatically set the position of the roller turning mechanism 3 so that the tire turning center C6 and the roller turning center C2 are in the closest positional relationship, and ideally, the roller turning center C2 coincides with the tire turning center C6.

[0236] As a result, the chassis dynamometer 1 of the present embodiment can accurately perform various running tests on the vehicle 60 without generating a tire position deviation phenomenon during the execution of the running test.

[0237] In chassis dynamometer 1 of this embodiment, the detected speed differences include a straight-line speed difference ΔV11, a left turning speed difference ΔV12, and a right turning speed difference ΔV13.

[0238] Therefore, when executing step S6, the control unit 80 of the chassis dynamometer 1 in this embodiment can accurately calculate multiple judgment speed differences (sum of speed differences SMV, maximum speed difference MXV) corresponding to multiple set positions based on the straight-line speed difference ΔV11, the left-turning speed difference ΔV12, and the right-turning speed difference ΔV13.

[0239] 23 as step S6, and determines the setting position corresponding to the minimum speed difference sum SMV(MIN), which is the smallest value among the multiple speed difference sums SMV, as the optimum setting position. Therefore, the chassis dynamometer 1 of this embodiment can determine the optimum setting position suitable for the comprehensive running test of the roller turning mechanism 3 by a relatively simple calculation process.

[0240] The control unit 80 executes steps S63 and S64 shown in Fig. 24 as step S6, and determines the setting position corresponding to the maximum speed difference minimum value MXV(MIN), which is the smallest value among the multiple maximum speed differences MXV, as the optimum setting position. Therefore, the chassis dynamometer 1 of this embodiment can determine the optimum setting position by taking into consideration local running tests of the roller turning mechanism 3 through relatively simple calculation processing. Note that "taking into consideration local running tests" means, for example, taking into consideration not to deteriorate limited running tests such as a "left turning running test."

[0241] The speed difference for determination is not limited to the sum of speed differences SMV and the maximum speed difference MXV described above, but can be set in various ways based on the speed difference between the detected speeds V1 and V2.

[0242] 14, which is included in step S4, the control unit 80 of the chassis dynamometer 1 of this embodiment executes the position change process in a roller rotation environment in which the rotation angle of the roller turning mechanism 3 is in the straight-line direction and the front roller 20F, which is the first roller, is rotated at a constant speed. This makes it possible to avoid the phenomenon of deformation of the tire 6 when the position change process of step S4 is executed.

[0243] This is because performing the position change process while rotating the front rollers 20F does not apply excessive force to the tire 6. On the other hand, if the position change process is performed while stopping the rotation of the front rollers 20F, the tire 6 is more likely to be deformed.

[0244] As a result, the chassis dynamometer 1 of this embodiment can improve the accuracy of the detected speeds V1 and V2, which are the first and second detected speeds obtained in step S3, thereby improving the accuracy of the optimal setting position determined in step S6.

[0245] The chassis dynamometer 1 of this embodiment includes roller devices 2L and 2R as the roller device 2. Therefore, when executing step S6, the control unit 80 can calculate a balanced judgment speed difference between the left and right tires 6L and 6R based on the left detected speed difference and the right detected speed difference.

[0246] The left detected speed differences include a speed difference ΔV11L when traveling straight, a speed difference ΔV12L when turning left, and a speed difference ΔV13L when turning right, and the right detected speed differences include a speed difference ΔV11R when traveling straight, a speed difference ΔV12R when turning right, and a speed difference ΔV13R when turning right.

[0247] Therefore, the chassis dynamometer 1 of this embodiment can determine an optimal setting position that achieves a good balance between the tires 6L and 6R.

[0248] The chassis dynamometer 1 of the present embodiment has a position changing mechanism MV that includes left-right movement mechanisms 4B and 4T and front-rear movement mechanisms 5B and 5T, and that executes the position changing process described above.

[0249] Here, consider a case where, in the initial state in which the tire 6 of the vehicle 60 is placed on the roller pair 20 of the roller device 2, the tire rotation center C6 and the roller rotation center C2 are misaligned as shown in Figures 26(a) and (b).

[0250] That is, in the initial state, as shown in Figures 26(a) and 26(b), it is assumed that there is a deviation DX (DX2) in the X direction and a deviation DY (DY2) in the Y direction between the tire rotation center C6 and the roller rotation center C2.

[0251] As described above, the roller device 2 (2L, 2R) in the chassis dynamometer 1 of this embodiment has a position changing mechanism MV including the left-right movement mechanisms 4B and 4T and the front-rear movement mechanisms 5B and 5T shown in Figures 2 to 6. This position changing mechanism MV can execute a position changing process that changes the position of the roller turning mechanism 3 (roller turning center C2) relative to the tire turning center C6 of the tire 6 placed on the roller pair 20.

[0252] Therefore, the control unit 80 of the chassis dynamometer 1 of this embodiment controls the position changing mechanism MV to execute the position changing process of the roller turning mechanism 3 in each of steps S4 and S7.

[0253] Furthermore, the chassis dynamometer 1 of this embodiment can change the position of the roller turning mechanism 3 relative to the tire turning center C6 of the tire 6 placed on the roller pair 20 while the tire 6 is placed on the roller pair 20, and ultimately set the roller turning mechanism 3 to an optimal setting position.

[0254] Therefore, in the chassis dynamometer 1 of this embodiment, the roller turning mechanism 3 can be disposed at an optimum setting position where the tire turning center C6 and the roller turning center C2 ideally coincide with each other.

[0255] As a result, the chassis dynamometer 1 of this embodiment can perform a running test of the vehicle 60 with high accuracy, which involves tire turning motion and roller turning motion, without causing the tire position deviation phenomenon during the running test.

[0256] By simultaneously executing the position change process for the roller device 2L and the roller device 2R of the chassis dynamometer 1, the position change process can be executed in a well-balanced manner between the tires 6L and 6R without moving the vehicle 60. The position change process includes first and second left-right movement processes (steps S41 to S44) and first and second front-rear movement processes (steps S45 to S48).

[0257] The chassis dynamometer 1 of this embodiment has forward / rearward movement mechanisms 5B and 5T5 in addition to left / right movement mechanisms 4B and 4T. The forward / rearward movement mechanisms 5B and 5T can execute first and second forward / rearward movement processes.

[0258] In this way, the chassis dynamometer 1 of this embodiment places the tire 6 of the vehicle 60 on the roller pair 20 and executes the turning center setting process shown in steps S3 to S7 of Figure 12, thereby making it possible to position the roller turning mechanism 3 at an optimal setting position, ideally so that the tire turning center C6 and the roller turning center C2 coincide when viewed in a plane.

[0259] Therefore, by placing the roller turning mechanism 3 at the optimal setting position, various driving tests can be performed on the vehicle 60 with the tire turning center C6 and the roller turning center C2 ideally aligned, thereby significantly improving the accuracy of the driving tests of the vehicle 60 involving roller turning motion and tire turning motion.

[0260] This point will be described in detail below. Figure 25 is an explanatory diagram showing the above-mentioned effects of the chassis dynamometer 1 of this embodiment.

[0261] 25(a) and (b) are plan and side views showing the positional relationship between the roller pair 20 (20F, 20B) and the tire 6 when the vehicle is moving straight ahead (initial state), and Fig. 25(c) and (d) are plan and side views showing the positional relationship between the roller pair 20 and the tire 6 when the tire 6 of the vehicle and the roller pair 20 are turned. An XYZ Cartesian coordinate system is shown in each of Figs. 25(a) to (d).

[0262] 25, the front roller 20F is used as a load roller, and the rear roller 20R is used as a free roller. Therefore, the tire rotation direction K2F of the front roller 20F and the tire rotation direction K6 of the tire 6 are in an opposite relationship, and the tire rotation direction K6 of the tire 6 and the tire rotation direction K2R of the rear roller 20R are in an opposite relationship.

[0263] For ease of comparison with Figures 25(a) and (b), the X-axis and Y-axis shown in Figures 25(c) and (d) are made to coincide with the X-axis and Y-axis in Figures 25(a) and (b) for convenience. In reality, the relationship between the tire 6 and the roller pair 20 and the X-axis and Y-axis changes with the roller turning operation and the tire turning operation.

[0264] 25, the roller turning mechanism 3 can perform a roller turning operation to turn the roller pair 20 along the roller turning direction R2 about the roller turning center C2. Meanwhile, the vehicle 60 can perform the tire turning operation described above.

[0265] The effect of the roller device 2 having a twin-roller configuration with the roller pair 20 will be described with reference to FIG.

[0266] As shown in Figures 25(a) and (b), as a result of executing the turning center setting process shown in steps S3 to S7 of Figure 12, ideally, the tire turning center C6 of the tire 6 and the roller turning center C2 of the roller pair 20 coincide with each other.

[0267] For example, consider the case where immediately after execution of step S2 in FIG. 12, a positional deviation between the turning centers including deviations DX2 and DY2 occurs between the roller turning center C2 and the tire turning center C6, as shown in FIGS. 26(a) and (b).

[0268] Even in such a case, after executing the turning center setting process shown in steps S3 to S7 of FIG. 12, ideally, the tire turning center C6 and the roller turning center C2 can be aligned in the XY plane as shown in FIGS. 25(a) and (b).

[0269] The following describes Figure 25. As shown in Figures 25(a) and (b), when the vehicle 60 is traveling straight, the positional relationship between the tire 6 and the roller pair 20 remains constant and does not change.

[0270] Furthermore, as shown in FIGS. 25(c) and 25(d), even if the tire turning operation and the roller turning operation are performed, the positional relationship between the tire 6 and the roller pair 20 remains constant and does not change.

[0271] In this way, the chassis dynamometer 1 of this embodiment automatically positions the roller turning mechanism 3 at the optimal setting position, thereby enabling running tests involving tire turning movements and roller turning movements to be performed on the vehicle 60, ideally with the tire turning center C6 and the roller turning center C2 coinciding.

[0272] That is, as shown in FIG. 25, the chassis dynamometer 1 of this embodiment places the tire 6 of the vehicle 60 on the roller pair 20 of the roller device 2, and can accurately perform a running test of the vehicle 60 involving tire turning motion and roller turning motion without causing tire position shift phenomenon during the running test.

[0273] Returning to Fig. 2, the roller device 2 (2L, 2R) in the chassis dynamometer 1 of this embodiment has a roller turning mechanism 3, left / right movement mechanisms 4B and 4T, and front / rear movement mechanisms 5B and 5T provided along the height direction (Z direction) between the base stand 25 and a roller drive mechanism 8 having a roller pair 20. For this reason, the roller device 2 of this embodiment can be provided with the roller turning mechanism 3, left / right movement mechanisms 4B and 4T, and front / rear movement mechanisms 5B and 5T without increasing the device area.

[0274] <Other> In the above-described embodiment, the chassis dynamometer 1 is taken up as the vehicle testing device, but the vehicle testing device is not limited to the chassis dynamometer. For example, a free roller testing device may be used as the vehicle testing device instead of the chassis dynamometer 1. The free roller testing device is a device that applies acceleration / deceleration load to the vehicle 60 only by the weight of the roller pair 20, and is a device that does not transmit power to the roller pair 20.

[0275] However, in the free roller test device, the front roller 20F can be rotated via a belt or the like when positioning the roller turning mechanism 3. Therefore, even a device that does not have a motor for applying a load to the roller pair 20, such as a chassis dynamometer, can be used as a vehicle test device.

[0276] Thus, the vehicle testing apparatus of the present disclosure includes a chassis dynamometer and a free roller testing apparatus.

[0277] In addition, in the present disclosure, the embodiments can be modified or omitted as appropriate within the scope of the disclosure. [Explanation of symbols]

[0278] 1 Chassis dynamometer 2,2L,2R roller device 3 Roller turning mechanism 4B,4T Left and right movement mechanism 5B,5T Back and forth movement mechanism 6,6L,6R Tires 8 Roller drive mechanism 20 Laura Vs. 20F Front roller 20R Rear roller 60 vehicles 80 Control section 81, 81L, 81R, 82, 82L, 82R Rotation detector C2 Roller rotation center C2L Left roller turning center C2R Right roller turning center C6 tire turning center C6L Left tire turning center C6R Right tire turning center MV position change mechanism

Claims

1. A vehicle testing device including a roller device and a control unit, The roller device includes: First and second rollers on which a vehicle tire is placed; a roller driving mechanism that performs a roller driving operation to rotate the first roller; a first rotation detector that detects a rotation speed of the first roller to obtain a first detected speed; a second rotation detector that detects a rotation speed of the second roller to obtain a second detected speed; a roller turning mechanism that performs a roller turning operation to turn the first and second rollers; a position changing mechanism that executes a position changing process to change a position of the roller turning mechanism with respect to a tire turning center of a tire placed on the first and second rollers, The first roller is used as a load roller that rotates by itself, and the second roller is used as a free roller that rotates in conjunction with the rotation of a tire, The control unit is receiving the first and second detected velocities, controlling the roller driving mechanism, the roller turning mechanism, and the position changing mechanism to perform the roller driving operation, the roller turning operation, and the position changing process; A plurality of set positions are prepared as positions of the roller turning mechanism relative to the tire turning center, the control unit sets the roller turning mechanism to an initial setting position included in the plurality of setting positions, and executes a turning center setting process in a state where tires of the vehicle are placed and fixed on the first and second rollers; The turning center setting process includes: (a) executing the roller turning operation and the roller driving operation, and rotating the first roller while setting the first and second rollers in a predetermined turning direction, to perform a temporary running test of the vehicle and obtain the first and second detected speeds; (b) executing the position change process to change the position of the roller turning mechanism to a new setting position included in the plurality of setting positions; (c) repeatedly executing steps (a) and (b) until step (a) is executed at all of the plurality of set positions; and (d) calculating a plurality of speed differences for determination corresponding to the plurality of set positions based on a detected speed difference between the first and second detected speeds for each of the plurality of set positions, and determining a set position corresponding to a speed difference for determination that is a minimum value among the plurality of speed differences for determination as an optimal set position; (e) executing the position change process and moving the roller turning mechanism to the optimal setting position. Vehicle testing equipment.

2. 2. The vehicle testing apparatus according to claim 1, The step (a) (a-1) performing a straight running test of the vehicle by rotating the first roller in a manner that accelerates and decelerates the rotation speed while the first and second rollers are set in a straight running direction, and obtaining the first and second detected speeds as first and second detected speeds during straight running; (a-2) performing a left-turn running test of the vehicle by rotating the first roller in a manner that accelerates and decelerates the rotation speed while the first and second rollers are set in a left-turn direction, and obtaining the first and second detected speeds as first and second detected speeds during left turning; (a-3) performing a right-turn running test of the vehicle by rotating the first roller in a manner in which the rotation speed is accelerated or decelerated while the first and second rollers are set in a right-turn direction, and obtaining the first and second detected speeds as first and second detected speeds during right turning, The predetermined turning direction includes the straight direction, the left turning direction, and the right turning direction, The provisional running test includes the straight running test, the left turning running test, and the right turning running test, The first detected speed includes the first detected speed when traveling straight, the first detected speed when turning left, and the first detected speed when turning right, The second detected speed includes the second detected speed when traveling straight, the second detected speed when turning left, and the second detected speed when turning right, The detected speed differences include a straight-line speed difference that is a speed difference between the first and second detected speeds when traveling straight, a left-turn speed difference that is a speed difference between the first and second detected speeds when turning left, and a right-turn speed difference that is a speed difference between the first and second detected speeds when turning right. Vehicle testing equipment.

3. 3. The vehicle testing apparatus according to claim 2, The speed difference for determination includes a speed difference sum that is a sum of the straight-line speed difference, the left turning speed difference, and the right turning speed difference, and a plurality of speed difference sums correspond to the plurality of set positions. Vehicle testing equipment.

4. 3. The vehicle testing apparatus according to claim 2, The speed difference for determination includes a maximum speed difference that is a maximum value among the straight-line speed difference, the left turning speed difference, and the right turning speed difference, and a plurality of maximum speed differences correspond to the plurality of set positions. Vehicle testing equipment.

5. A vehicle testing apparatus according to any one of claims 1 to 4, The step (b) (b-1) executing the roller turning operation and the roller driving operation, and rotating the first roller at a constant speed in a state in which the first and second rollers are set in a straight direction; (b-2) executing the position change process under the roller rotation environment set in the step (b-1) to change the position of the roller turning mechanism to a new set position; Vehicle testing equipment.

6. A vehicle testing apparatus according to any one of claims 1 to 4, the roller device is a device for supporting a pair of front or rear tires of the vehicle, the pair of tires including a left tire and a right tire; The roller device includes: a left roller device provided corresponding to the left tire of the vehicle; a right roller device provided corresponding to the right tire of the vehicle, the left roller device and the right roller device simultaneously execute the position change process; the first and second detected speeds obtained by the first and second rotation detectors of the left-hand roller device are defined as left-hand first and second detected speeds, the first and second detected speeds obtained by the first and second rotation detectors of the right roller device are defined as right first and second detected speeds, the detected speed difference includes a left detected speed difference between the left first detected speed and the left second detected speed, and a right detected speed difference between the right first detected speed and the right second detected speed, Vehicle testing equipment.

Images