Testing apparatus of steering system

• US 5,700,951 A
• Filed: 05/29/1996
• Issued: 12/23/1997
• Est. Priority Date: 06/08/1995
• Status: Expired due to Fees

• Current Assignee: Kabushiki Kaisha Saginomiya Seisakusho, Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Kabushiki Kaisha Saginomiya Seisakusho, Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Iizuka, Hitoshi, Sagiyama, Tatsuya, Matsushima, Takashi, Saito, Kaname, Baba, Fumihiko
• Primary Examiner(s): Dougherty, Elizabeth L.
• Assistant Examiner(s): MCCALL, ERIC SCOTT
• Application Number:
  US08/654,592
• Time in Patent Office: 573 Days
• Field of Search: 73/11.04, 73/1.07, 73/1.08, 73/663, 73/669, 73/798, 73/816
• US Class Current: 73/11.08
• CPC Class Codes: G01M 17/06 Steering behaviour; Rolling behaviour

Abstract

A testing apparatus of a steering system is provided to correctly detect load in a direction in which steering reaction force acts, the load being applied to the steering system. A tie rod connected to a rack of the steering system is connected to a steering-angle vibrating unit via a torque lever, relay links and a drive link. A front link of the drive link and a link disposed parallel to the torque lever are provided in a swingable manner. Both ends of each of the relay links are respectively connected to the torque lever and the link disposed parallel to the torque lever, and the torque lever is swingable with respect to the link in a direction in which road-surface reaction force acts. Transducers are provided at intermediate portions of the relay links, respectively. A vertically-vibrating unit is connected via the torque lever to the rack.

Claims

1. A testing apparatus of a steering system, having a first loading device for applying, to the steering system, load in a direction in which steering reaction force acts, and a second loading device for applying, to the steering system, load in a direction in which road-surface reaction force acts, said testing apparatus comprising:

first links formed from a pair of parallel link portions; and

second links which include a pair of parallel link portions disposed in a direction crossing said first links, each of the pair of parallel link portions of said second links being connected to said first links at two points such that one of said first links can be displaced with respect to the other in the direction in which road-surface reaction force acts and said first links can swing,

wherein the second loading device and a wheel-side connecting portion of the steering system are connected to the one of said first links;

the first loading device is connected to the other of said first links via a connecting mechanism which allows the other of said first links to swing about a center of rotation in a central portion of said other of said first links between two connecting points of said second links to said other of said first links, due to loading of the first loading device; and

a first load detector is mounted to one of said second links and a second load detector is mounted to the other of said second links.

2. A testing apparatus of a steering system according to claim 1, wherein the first loading device is a steering-angle vibrating unit.

3. A testing apparatus of a steering system according to claim 1, wherein the second loading device is a vertically-vibrating unit.

4. A testing apparatus of a steering system according to claim 1, wherein the one of said first links is a torque lever to which a vibrating shaft, whose axis is substantially vertical is integrally connected at a substantially central portion in a longitudinal direction of the torque lever, and the second loading device is connected to the one of said first links via the vibrating shaft.

5. A testing apparatus of a steering system according to claim 4, wherein upper and lower ends of the vibrating shaft are connected to an asymmetric link formed from an upper link section and a lower link section via ball joints, and synchronously with swinging of the torque lever on a horizontal plane, the vibrating shaft is rotatable around the axis thereof with these ball joints serving as supporting points.

6. A testing apparatus of a steering system according to claim 5, wherein a pivotally supporting point of the upper link section and the lower link section, and the wheel-side connecting portion of the steering system are located on a hyperbola.

7. A testing apparatus of a steering system according to claim 1, wherein the wheel-side connecting portion of the steering system is a rack of the steering system and is connected via a tie rod to a rear end portion of the one of said first links.

8. A testing apparatus of a steering system according to claim 1, wherein the connecting mechanism is a drive link including a front link and a parallel link, the front link being provided to be swingable on a horizontal plane and around a fixed support shaft due to actuation of the first loading device connected to the front link and the parallel link connecting the front link and the other of said first links.

9. A testing apparatus of a steering system according to claim 1, wherein the first and second load detectors are transducers.

10. A testing apparatus of a steering system according to claim 1, wherein the first and second load detectors are respectively set so as to detect outputs which have identical signs when compressed.

11. A testing apparatus of a steering system according to claim 10, wherein said identical signs are positive.

12. A testing apparatus of a steering system according to claim 1, wherein load in the direction in which steering reaction force acts is detected from a difference of respective outputs of the first and second load detectors.

13. A testing apparatus of a steering system according to claim 1, wherein the first load detector and the second load detector are transducers which are respectively set so as to detect positive outputs when compressing, and force in the direction in which steering reaction force acts is detected from a difference of respective outputs of the transducers.

14. A testing apparatus of a steering system, having a steering-angle vibrating unit for applying, to the steering system, load in a direction in which steering reaction force acts, and a vertically-vibrating unit for applying, to the steering system, load in a direction in which road-surface reaction force acts, said testing apparatus comprising:

first links formed from a pair of parallel link portions; and

second links which include a pair of parallel link portions disposed in a direction crossing said first links, each of the pair of parallel link portions of said second links being connected to said first links at two points such that one of said first links can be displaced with respect to the other in the direction in which road-surface reaction force acts and said first links can swing,

wherein the vertically-vibrating unit is connected to the one of said first links via a vibrating shaft of which axial direction coincides with a vertical direction and which is integrally connected with the one of said first links at a substantially central portion in a longitudinal direction of the one of said first links, and a wheel-side connecting portion of the steering system is connected to a rear end portion of the one of said first links;

the steering-angle vibrating unit is connected to the other of said first links via a connecting mechanism which allows the other of said first links to swing about a center of rotation in a central portion of the other of said first links between the two connecting points of said second links to the other of said first links, due to load of the steering-angle vibrating unit; and

transducers for detecting load are mounted to one and the other of said second links, respectively, and force in the direction in which steering reaction force acts is detected from a difference of respective outputs of the transducers.

15. A testing apparatus of a steering system according to claim 14, wherein upper and lower ends of the vibrating shaft are connected to an asymmetric link formed from an upper link section and a lower link section via ball joints, and synchronously with swinging of the one of said first links on a horizontal plane, the vibrating shaft is rotatable around the axis thereof with these ball joints serving as supporting points.

16. A testing apparatus of a steering system according to claim 14, wherein the connecting mechanism is a drive link including a front link and a parallel link, the front link being provided to be swingable on a horizontal plane and around a fixed support shaft due to actuation of a hydraulic cylinder of the steering-angle vibrating unit connected to the front link and the parallel link connecting the front link and the other of said first links.

17. A testing apparatus of a steering system according to claim 14, wherein the wheel-side connecting portion of the steering system is a rack of the steering system and is connected via a tie rod to a rear end portion of the one of said first links.