Tire restraint device for vehicles

Abstract

The objective of the present invention is to restrain a tire in a turnable manner without scratching or damaging a vehicle body, the tire, or the like, of a test vehicle. Plates 6 have one end portion 6a arranged respectively in front of and behind a front tire 1a of a test vehicle 1 placed on a roller device 19 of a chassis dynamometer system 2. Groups of free rollers 8 are arcuately arranged on the one end portions 6a of the plates 6 so as to sandwich the front tire 1a. Each of the free rollers 8 is axially supported by a bracket 7 so as to be free to rotate.

Description

Vehicle tire restraint device

[0001] The present invention relates to a device for restraining a tire of a vehicle so that the tire can turn.

[0002] As is well known, a chassis dynamometer system is used to perform various measurements such as fuel economy and exhaust gas measurements during a running test of a test vehicle, and is equipped with a vehicle restraint device that restrains and fixes the test vehicle placed on a roller device. Examples of such vehicle restraint devices are known from Patent Documents 1 to 3, for example.

[0003] (1) The vehicle restraint device of Patent Document 1 restrains the body of the test vehicle to restrict longitudinal movement (forward and backward), and performs vehicle testing without steering the tires.

[0004] However, in evaluation tests for autonomous driving (hereinafter referred to as "AD") and advanced driver assistance systems (hereinafter referred to as "ADAS") that detect and avoid potential accidents in advance, steering angle tests are conducted using sensors.

[0005] If an attempt is made to steer the tires by operating the steering wheel at this time, stress in directions other than the longitudinal direction will be applied to the joint between the test vehicle and the fixing device, which could cause damage to the vehicle body. For example, since the rigidity of the side sills in the lateral direction of the vehicle is low, if the side sills of the test vehicle are fixed in place, there is a risk of damage due to steering operation.

[0006] (2) The hub nut clamp type vehicle restraint device of Patent Document 2 (see Figures 3 and 4 of Patent Document 2) provides freedom of movement to the vehicle body by restraining the hub nut rather than the body of the test vehicle.

[0007] This vehicle restraint device allows for vehicle yawing and other movements, making it possible to simulate conditions similar to those of on-road driving; however, factors such as the number of holes in the tire / wheel, the hub diameter, the wheel offset, and the PCD (Pitch Circle Diameter) must be taken into consideration.

[0008] As a result, it becomes necessary to prepare a huge number of combinations of mounting jigs for connecting the vehicle restraint device to the wheel. Providing multiple mounting jigs for different vehicle restraint devices and wheels in this way can be inefficient and can increase costs.

[0009] Furthermore, when attempting to steer the vehicle during testing of "AD" or "ADAS," the vehicle restraint device interferes with the tires, resulting in a small movement of the steering angle within a limited range, which may prevent accurate detection.

[0010] (3) The chain-type restraint device of Patent Document 2 (see FIGS. 1 and 2 of Patent Document 2) restrains the towing hook of the test vehicle with a chain, etc. Therefore, when a sensor evaluates the steering angle, etc., stress is applied to the towing hook in a direction other than the front-rear direction, i.e., stress in the left-right direction, which may damage the towing hook.

[0011] Furthermore, sensors mounted on the test vehicle may detect the chain-type restraint device as an obstacle, which may interfere with the actual testing and evaluation. Therefore, a vehicle restraint device described in Patent Document 3 has been proposed for testing "AD" and "ADAS."

[0012] JP 2011-33517 A, JP 02-48854 B, JP 2022-29655 A

[0013] According to the vehicle high-speed device of Patent Document 3, a test vehicle is equipped with a sensor that detects the steering angle. In response to the detection signal from this sensor, a tire holding device is turned in synchronization with the tires of the test vehicle.

[0014] However, since the tire fixing device turns in synchronization with the steering angle, there is a risk of a discrepancy occurring between the actual steering angle of the tire and the actual steering angle of the tire, which could damage the tire of the test vehicle.

[0015] Furthermore, the vehicle restraint device of Patent Document 3 clamps and secures the vehicle's side sill with left and right clamps, so there is a risk of damage to the vehicle body due to turning of the tires, just like Patent Document 1.

[0016] The present invention has been made to solve such conventional problems, and its problem is to restrain the tires so that they can turn without causing damage to the body or tires of the test vehicle.

[0017] (1) The present invention is a device for restraining a vehicle tire so that it can turn, comprising: a tire mounting member on which the tire is placed; and a group of free rollers arranged in an arc around the tire placed on the tire mounting member and restraining the tire, wherein each of the free rollers is arranged vertically so as to be freely rotatable.

[0018] (2) In one aspect of the present invention, the tire includes a set of free rollers at the front and rear of the tire. In this case, each set of free rollers may be provided on a pair of plates.

[0019] (3) In another aspect of the present invention, the position of each free roller group can be adjusted by moving each plate in the longitudinal direction or width direction of the vehicle, and the height of each free roller group can be adjusted by placing spacers under the plates.

[0020] (4) In yet another aspect of the present invention, the free rollers are rotatably supported by brackets erected on the plate. In this case, the brackets may be erected inclined in the same direction, and the free rollers may be inclined obliquely.

[0021] The bracket may be provided with a rotatable auxiliary roller for preventing the tire from going off the track. The auxiliary roller is preferably positioned higher than the free roller.

[0022] (5) The tire mounting member may be, for example, a roller device of a chassis dynamometer system.

[0023] According to the present invention, the tires can be restrained so as to be able to turn without causing any damage to the body or tires of the test vehicle.

[0024] 1 is a perspective view of a first embodiment; a perspective view showing the arrangement of a group of free rollers; an enlarged view of the free rollers and bracket; and a diagram of a fixing structure of the plate; (a) is a perspective view before the tire turns, and (b) is a perspective view after the tire turns; a perspective view of a second embodiment; a perspective view showing the arrangement of a group of free rollers; (a) is a perspective view before the tire turns, and (b) is a perspective view after the tire turns; a perspective view of a third embodiment; a perspective view showing the arrangement of a group of free rollers; and an enlarged view of the free rollers and bracket; (a) is a perspective view before the tire turns, and (b) is a perspective view after the tire turns.

[0025] A tire restraint device for a vehicle according to an embodiment of the present invention will be described below, with an example of application to a chassis dynamometer system that simulates the running conditions of a test vehicle.

[0026] That is, the chassis dynamometer system places the tires of a test vehicle on a roller device, connects a dynamometer to the roller device, and transmits the driving force and braking force of the test vehicle to the dynamometer via the roller device, simulating the test vehicle's on-road driving indoors.

[0027] Here, the control device of the chassis dynamometer system is equipped with an "AD / ADAS" sensor evaluation test system that performs evaluation tests such as synchronization and operation confirmation of on-board sensors for "AD / ADAS," and performs steering angle tests using the sensors.

[0028] In this case, the tire restraint device employs a structure in which the tires of the test vehicle are restrained by a group of free rollers, thereby enabling steering by steering operation of the vehicle without modifying the body of the test vehicle. Hereinafter, the tire restraint device will be described based on Examples 1 to 3.

[0029] The first embodiment will be described with reference to Figures 1 to 5. In Figure 1, reference numeral 1 denotes a test vehicle, and reference numeral 2 denotes the chassis dynamometer system.

[0030] <Configuration Example> The chassis dynamometer system 2 includes a pit cover 4 that forms a floor above the pit 3. A pair of left and right rails 12, each having a concave cross section, are embedded in the pit cover 4 along the longitudinal direction of the test vehicle 1 (the Y-Y direction in FIG. 5) (see FIG. 4).

[0031] The pit cover 4 is also formed with four openings (not shown) at positions corresponding to the front and rear wheels (front and rear tires 1a, 1b) of the test vehicle 1. As shown in Figures 1 and 2, each opening is provided with a roller device 19 on which the tires 1a, 1b of the test vehicle 1 are placed. Here, a group of free rollers 8 is arranged in a substantially elliptical shape around the front tire 1a placed on the roller device 19, and restrains the front tire 1a.

[0032] Specifically, as shown in Figure 2, spacer panels 25 are placed on the pit cover 4 in front of and behind the roller device 19. A pair of front and rear plates 6 are placed on the spacer panels 25 at a distance that allows the front tire 1a to turn. Each plate 6 is formed in a roughly rectangular shape and is movably attached to the rails 12.

[0033] An arc-shaped cutout 10 is formed in one end 6a of each plate 6, and each front tire 1a is positioned between the cutouts 10 formed in the front and rear plates 6. A plurality of brackets 7 formed in a substantially rectangular shape are erected along the inner periphery of this cutout 10 by welding or the like, thereby forming a group of brackets 7 arranged in an arc shape.

[0034] Each bracket 7 is formed with a through hole (not shown), and as shown in FIG. 3, a shaft 14 is inserted and fixed into the through hole, and the free roller 8 is rotatably supported on the shaft 14 .

[0035] That is, a central hole 8a is formed in each free roller 8, and a shaft 14 is rotatably inserted through the central hole 8a. As a result, each free roller 8 is arranged approximately vertically on each bracket 7, and as shown in Figure 2, the groups of free rollers 8 on the front and rear plates 6 are arranged in an arc on the pit cover 4 so as to sandwich the front tire 1a from the front and rear.

[0036] 4 and 5, a pair of elongated holes 11 are formed in the other end 6b of each plate 6 along the width direction (X-X direction) of the test vehicle 1. A slot nut 18 having a female threaded hole is mounted in the rail groove 12a of the rail 12 so as to be movable along the Y-Y direction.

[0037] Here, the shaft of the bolt 13 is fastened to the female threaded hole through each long hole 11, causing the slot nut 18 to rise, and the rail piece 12b of the rail 12 is sandwiched between the lower end 18a of the slot nut 18 and the inner peripheral edge of the long hole 11, thereby fixing the other end 6b of the plate 6.

[0038] At this time, the positions of the free rollers 8 can be changed in the same direction by loosening the bolts 13 and moving the slot nuts 18 in the Y-Y direction. The positions of the free rollers 8 can also be changed in the same direction by moving the plates 6 in the X-X direction along the elongated holes 11. This makes it possible to freely adjust the positions of the free rollers 8 on each plate 6 according to the magnitude of the turning of the front tire 1a, etc.

[0039] <<Operation Example>> The restraint operation during the AD / ADAS sensor evaluation test will be described with reference to Figure 5. Here, the left and right front tires 1a of the test vehicle 1 are placed on the roller device 19, and then one end 6a of each plate 6 is placed in front of and behind each front tire 1a via a spacer panel 25, so that the front and rear of the front tire 1a are sandwiched between groups of free rollers 8, as shown in Figure 5(a).

[0040] As a result, during test driving on the roller device 19, the front tire 1a comes into contact with the free rollers 8, and the free rollers 8 rotate synchronously, restraining the front tire 1a. Also, as shown in Figure 5(b), when the vehicle is steered, the front tire 1a comes into contact with the free rollers 8 one after another in the turning direction, restraining the front tire 1a so that it can turn.

[0041] Therefore, there is no need to clamp the side sill of the test vehicle 1 with left and right clamps as in Patent Documents 1 and 3, and damage to the vehicle body due to steering operation can be avoided. Furthermore, even if a discrepancy occurs between the detected steering angle and the actual steering angle, the free rollers 8 rotate synchronously, so there is no risk of damaging the front tire 1a of the test vehicle 1 as in Patent Document 3. This provides the following effects.

[0042] (1) Since the position of the plate 6 can be moved in accordance with the turning of the front tire 1a, by adjusting the position of the group of free rollers 8, it becomes possible to steer the test vehicle by operating the steering wheel without modifying the test vehicle that does not have a towing hook or side sill as in Patent Documents 1 to 3, and without damaging the vehicle body.

[0043] (2) There is no need to provide a sensor or the like on the handlebars to rotate the tire fixing device in sync with the tire, as in Patent Document 3, and there is no need to prepare multiple mounting jigs (attachments) as in the hub nut clamp restraint device of Patent Document 2. This makes it easier to work and to manage the schedule for vehicle testing.

[0044] Furthermore, since the free rollers 8 rotate synchronously even when they come into contact with the front tire 1a during cornering, steering is not limited to small turns as in the hub nut clamp restraint device of Patent Document 2.

[0045] In addition, in this embodiment, since the front tire 1a is restrained so as to be able to turn by the group of free rollers 8, there is no need to use a sensor for detecting the steering angle as in Patent Document 3, and it is fully compatible with vehicles without steering wheels, such as self-driving cars.

[0046] (3) Since there is no need to restrain the body of the test vehicle, the number of objects to be detected by the on-board sensor for the AD / ADSA test can be reduced, which makes it possible to avoid objects being detected as obstacles by the on-board sensor as in the chain-type restraint device of Patent Document 2.

[0047] (4) Since the tie dimensions of the front tire 1a vary widely, it is preferable to adjust the height of the group of free rollers 8 by changing the number of spacer panels 25 interposed between the pit cover 4 and the plate 6 as needed.

[0048] Example 2 will be described with reference to Figures 6 to 8. In this example, as shown in Figures 6 and 7, each bracket 7 is inclined toward the test vehicle 1 by an angle ranging from about 5 degrees to 15 degrees.

[0049] Here, each free roller 8 is rotatably supported by each bracket 7 via a shaft 14, as in the first embodiment. Therefore, each free roller 8 is vertically placed at an angle and in the same direction as the bracket 7. Here, the front and rear groups of free rollers 8 placed vertically at an angle are each arranged in an arc, and the front tire 1a is sandwiched between both groups of free rollers 8 from the front and rear.

[0050] According to this embodiment, as shown in FIG. 8(b), the normal to the shoulder surface of the front tire 1a and the free roller 8 can come into perpendicular contact when cornering, so the load applied to the free roller 8 and the front tire 1a can be reduced more than in the first embodiment, and in this respect the lifespan of the front tire 1a can be extended.

[0051] A third embodiment will be described with reference to Figures 9 to 11. In this embodiment, each bracket 7 is configured as a double roller type equipped with not only free rollers 8 but also auxiliary rollers 20 for preventing deviation of the front tire 1a. Note that in Figures 12(a) and 12(b), due to space limitations, only some of the auxiliary rollers 20 are labeled with reference numerals.

[0052] 11, a support piece 21 is erected on the upper portion 7a of each bracket 7 in this embodiment, and an auxiliary roller 20 is rotatably and vertically supported on a shaft portion 22 supported by the support piece 21. In this embodiment, the auxiliary roller 20 is formed with a smaller diameter than the free rollers 8 and is positioned higher than the free rollers 8.

[0053] Therefore, according to this embodiment, even if the front tire 1a attempts to go over the free rollers 8 during test driving of the test vehicle 1, particularly when steering, it will hit the auxiliary rollers 20 and be restrained. This reduces the risk of the front tire 1a flying out, thereby improving safety.

[0054] The present invention is not limited to the above-described embodiment, and can be modified and implemented within the scope of the claims. For example, the present invention can be applied not only to restraining the front tire 1 a placed on the roller device 19 of the chassis dynamometer system 2, but also to a free roller device used in vehicle inspection, or a device that can place a tire on a rotating body such as a sphere.

[0055] In addition, in Examples 1 to 3, examples of restraining the front tire 1a were shown, but if the test vehicle is a 4WS (four-wheel steering) vehicle, for example, it can be used to restrain all four wheels including the rear tire 1b.

[0056] Furthermore, as in the second embodiment, a support piece 21 may be formed on the upper portion 7a of the oblique bracket 7, and an auxiliary roller 20 may be provided. In this case, the free roller 8 and the auxiliary roller 20 are placed obliquely vertically, reducing the load on the tire when preventing tire jump-out. Industrial application fields

[0057] The present invention is particularly suitable for use in the technical field of vehicle testing equipment such as chassis dynamometer systems.

[0058] DESCRIPTION OF SYMBOLS 1... Test vehicle 1a... Front tire 1b... Rear tire 2... Chassis dynamometer system 6... Plate 7... Bracket 8... Free roller 19... Roller device 20... Auxiliary roller 22... Spacer panel

Claims

1. A device for restraining a vehicle tire so that it can turn, comprising: a tire mounting member on which the tire is placed; and a group of free rollers arranged in an arc around the tire placed on the tire mounting member and restraining the tire, wherein each of the free rollers is disposed vertically so as to be freely rotatable.

2. The tire restraining device for a vehicle according to claim 1, characterized in that the free roller groups are provided in front of and behind the tire.

3. A tire restraining device for a vehicle according to claim 2, characterized in that the free roller groups on the front and rear of the tire are respectively provided on a pair of plates.

4. A tire restraining device for a vehicle as described in claim 3, characterized in that the positions of each of the groups of free rollers can be adjusted by moving each of the plates in the front-rear direction or width direction of the vehicle.

5. A tire restraining device for a vehicle as claimed in claim 3, characterized in that the height of each of the groups of free rollers can be adjusted by placing a spacer under the plate.

6. A tire restraining device for a vehicle as described in claim 3, characterized in that each of the free rollers is rotatably supported by a bracket erected on the plate.

7. A tire restraining device for a vehicle as claimed in claim 6, characterized in that each of the brackets is erected at an incline in the same direction, and each of the free rollers is inclined obliquely.

8. A vehicle tire restraining device as claimed in claim 6 or 7, characterized in that an auxiliary roller for preventing the tire from going out of alignment is rotatably mounted on the bracket.

9. A tire restraining device for a vehicle according to claim 8, wherein the auxiliary roller is disposed at a higher position than the free roller.

10. A vehicle tire restraint device according to claim 1, wherein said tire mounting member is a roller device of a chassis dynamometer system.

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