Test fixture for automotive wiper systems

• US 8,151,656 B2
• Filed: 06/09/2010
• Issued: 04/10/2012
• Est. Priority Date: 06/09/2010
• Status: Expired due to Fees

• Current Assignee: Robert Bosch GmbH, Robert Bosch LLC (Robert Bosch GmbH)
• Original Assignee: Robert Bosch GmbH
• Inventors: Nicgorski, Dana F II
• Primary Examiner(s): Caputo, Lisa
• Assistant Examiner(s): Dunlap, Jonathan
• Application Number:
  US12/797,292
• Publication Number:
  US 20110303021A1
• Time in Patent Office: 671 Days
• Field of Search: 738/620.41, 738/620.42, 738/620.43, 738/626.21, 738/626.25, 738/626.32, 738/626.37, 738/653, 73/7, 73/9, 738/658, 736/62, 736/63, 736/70, 736/71, 738/41, 738/55, 738/56, 738/58, 738/60, 738/66
• US Class Current: 73/865.3
• CPC Class Codes: B60S 1/0469 Devices for assisting the wiper positioning on the vehicle
• CPC Class Codes: G01M 99/005 Testing of complete machines, e.g. washing-machines or mobile phones testing of machine parts G01M13/00; testing of electric apparatus or components G01R31/50
• CPC Class Codes: G01M 99/007 by applying a load, e.g. for resistance or wear testing G01M99/001 takes precedence; testing the elasticity of structures G01M5/00

Abstract

A test fixture is provided for automotive wiper systems. The wiper system includes a plurality of connection points and one or more wiper arm connectors. The test fixture measures forces caused by the wiper system'"'"'s operation at the plurality of connection points while a resistive torque is applied to each of the wiper arm connectors. The test fixture allows for multiple attachment configurations to accommodate the many wiper system configurations that exist.

Claims

1. A test fixture for an automotive wiper system including a plurality of connection points, first and second wiper arm connectors, and a motor configured to move the first and second wiper arm connectors, test fixture comprising of:

first and second spaced apart support walls, each support wall having an inner surface and a top surface;

a base located between the inner surfaces of the first and second support walls;

first and second tracks coupled to the top surfaces of the first and second support walls, respectively;

first and second cross beams moveably coupled to the first and second tracks;

first and second brake assemblies coupled to the first and second cross beams, respectively, the first and second brake assemblies each including a brake support structure coupled to a respective one of the first and second cross beams so that each brake support structure is moveable along a longitudinal axis of the cross beam and is also rotatable relative to the cross beam, the first and second brake assemblies also including a brake coupled to the brake support structure and a connector coupled to a brake shaft of the brake, the connector being configured to be coupled to one of the wiper arm connectors so that the brake applies a resistive torque to the wiper arm connector;

a torque sensor mounted to each brake shaft of the first and second brake assemblies, the torque sensor measuring the resistive torque applied by the brake to the wiper arm connector;

a plurality of mounting blocks configured to be coupled to the base at a plurality of selected locations, each mounting block including a coupler configured to be coupled to one of the connection points of the wiper system; and

a plurality of force sensors, a force sensor being coupled between each coupler and the connection point of the wiper system, the force sensors measuring forces at the connection points of the wiper system during movement of the first and second wiper arm connectors by the motor.

2. The test fixture of claim 1, wherein the first and second support walls are formed from concrete.

3. The test fixture of claim 1, wherein the first and second support walls include a stair-stepped outer surface.

4. The test fixture of claim 1, wherein the first and second tracks each include a plurality of longitudinally extending slots configured to receive fasteners to secure the first and second cross beams to the first and second tracks.

5. The test fixture of claim 1, wherein the first and second cross beams each include a pair of beams coupled together to increase torsional stiffness of the cross beams.

6. The test fixture of claim 5, wherein the pair of beams are held spaced apart by a plurality of spacers.

7. The test fixture of claim 1, wherein a first natural resonance frequency of the first and second cross beams coupled to the first and second support walls is at least 200 Hz.

8. The test fixture of claim 1, wherein each of the first and second cross beams are releaseably secured to the first and second tracks by first and second mounting plates and a plurality of fasteners configured to couple the first and second mounting plates to the first and second tracks, respectively.

9. The test fixture of claim 1, wherein the base includes a top mounting plate having a plurality of mounting slots formed therein and at least one viscoelastic layer located below the top mounting plate, the viscoelastic layer being configured to isolate the top mounting plate from the floor.

10. The test fixture of claim 1, wherein the base includes a top mounting plate, a first viscoelastic layer located below the top mounting plate, a support plate located below the first viscoelastic layer, and a second viscoelastic layer located below the support plate.

11. The test fixture of claim 10, wherein the base includes a plurality of modular sections configured to be coupled together to form the base.

12. The test fixture of claim 1, wherein each brake support structure permits vertical adjustment of the brake relative to the first and second cross beams.

13. The test fixture of claim 12, wherein each brake support structure also permits rotation of the brake assembly about a mounting axis of the brake to the support structure.

14. The test fixture of claim 1, wherein each brake assembly further includes at least one flexible shaft coupling coupled between the brake shaft and the connector, that at least one shaft coupling allowing for misalignment of the brake shaft with the wiper arm connector and isolates the wiper system from vibrations of the first and second cross beams and the first and second support walls.

15. The test fixture of claim 1, wherein each wiper arm connector includes a mounting post having a tapered seat, and wherein each connector of each of the first and second brake assemblies includes a mounting member having a tapered opening configured to receive the tapered seat of the mounting post.

16. The test fixture of claim 15, wherein each connector of each of the first and second brake assemblies further includes a nut configured to engage the mounting post to pull the tapered seat of the mounting post into engagement with the tapered opening of the mounting member to secure the brake to the wiper arm connector.

17. The test fixture of claim 1, wherein each of the plurality of mounting blocks includes first and second spaced apart base members having a plurality of apertures formed therein, the first and second base members being secured to the base at selected locations, each of the plurality of mounting blocks also including a coupler positioned between the first and second base members and a plurality of fasteners extending through the apertures of the first and second base members to secure the coupler in a desired position between the first and second base members with a connecting portion of the coupler being attached to a connection point of the wiper system.

18. The test fixture of claim 17, wherein the coupler is clamped between the first and second base members and held in position therebetween without the plurality of fasteners passing through the coupler.

19. The test fixture of claim 17, wherein the first and second base members are T-shaped.

20. The test fixture of claim 19, further comprising first and second connecting blocks located over arms of the T-shaped base members to secure the base members to the base.

21. The test fixture of claim 17, wherein one of the plurality of force sensors is coupled to each coupler by a threaded stud.

22. The test fixture of claim 21, further comprising a connector coupled to each threaded stud, the connector including a threaded shaft configured to support a bushing thereon, the bushing being configured to be coupled to one of the connection points of the wiper system, and further comprising a disk located on the threaded shaft above the bushing and a nut coupled to the threaded shaft, the nut being adjustable to apply an axial pre-load force on the bushing.

23. The test fixture of claim 21, wherein the threaded stud applies an axial pre-load force to the force sensor.

24. The test fixture of claim 1, wherein the brakes of the first and second brake assemblies are configured to provide an adjustable resistive torque to the first and second wiper arm connectors of the wiper system during movement of the first and second wiper arm connectors by the motor, and wherein each of the plurality of force sensors provides output signals indicating forces detected along three axes for each of the plurality of connection points of the wiper system as the motor moves the first and second wiper arm connectors against the resistive forces of the brakes.

25. The test fixture of claim 1, wherein the brakes of the first and second brake assemblies each have five degrees of freedom of movement relative to the first and second support walls.

26. The test fixture of claim 1, wherein the wiper system includes a linkage providing the plurality of connection points and first and second wiper arm connectors, the motor being coupled to the linkage to move the linkage, thereby moving the first and second wiper arm connectors.

27. A test fixture for an automotive wiper system including a plurality of connection points, at least one wiper arm connector, and a motor configured to move the at least one wiper arm connector, the test fixture comprising of:

first and second spaced apart support walls, each support wall having an inner surface and a top surface;

a base located between the inner surfaces of the first and second support walls;

first and second tracks coupled to the top surfaces of the first and second support walls, respectively;

at least one cross beams moveably coupled to the first and second tracks;

at least one brake assembly, each brake assembly including a brake support structure coupled to a cross beam so that the brake support structure is moveable along a longitudinal axis of the cross beam and is also rotatable relative to the cross beam, the at least one brake assembly also including a brake coupled to the brake support structure and a connector coupled to a brake shaft of the brake, the connector being configured to be coupled to a wiper arm connector so that the brake applies a resistive torque to the wiper arm connector;

a torque sensor mounted to the brake shaft of the at least one brake assembly, the torque sensor measuring the resistive torque applied by the brake to the wiper arm connector;

a plurality of mounting blocks configured to be coupled to the base at a plurality of selected locations, each mounting block including a coupler configured to be coupled to one of the connection points of the wiper system; and

a plurality of force sensors, a force sensor being coupled between each coupler and the connection point of the wiper system, the force sensors measuring forces at the connection points of the wiper system during movement of the at least one wiper arm connector by the motor.

28. The test fixture of claim 27, wherein the brake of the at least one brake assembly is configured to provide an adjustable resistive torque to the at least one wiper arm connector of the wiper system during movement of the at least one wiper arm connector by the motor, and wherein each of the plurality of force sensors provides output signals indicating forces detected along three axes for each of the plurality of connection points of the wiper system as the motor moves the at least one wiper arm connector against the resistive forces of the brakes.

29. The test fixture of claim 27, wherein the brake of the at least one brake assembly has five degrees of freedom of movement relative to the first and second support walls.

30. The test fixture of claim 27, wherein the wiper system includes a linkage providing the plurality of connection points and first and second wiper arm connectors, the motor being coupled to the linkage to move the linkage, thereby moving the first and second wiper arm connectors.