Abnormality detecting device for vehicular hydraulic pressure control circuit

• US 6,907,970 B2
• Filed: 04/19/2004
• Issued: 06/21/2005
• Est. Priority Date: 05/15/2003
• Status: Expired due to Fees

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Sugimura, Toshio
• Primary Examiner(s): Butler, Douglas C.
• Application Number:
  US10/826,378
• Publication Number:
  US 20040226785A1
• Time in Patent Office: 428 Days
• Field of Search: 188/382, 188/151.A, 188/182, 303/1, 303/DIG.3, 303/DIG.4, 303/122.03, 303/122.05, 477/906, 477/129, 477/127, 477/130, 477/131, 477/152, 477/142, 477/34, 477/50, 477/158, 477/107, 477/150, 477/174, 477/146, 477/161, 477/117, 477/45, 701/51, 701/66, 701/62, 701/63, 280/5.501, 280/124.161, 251/129.01, 251/129.22
• US Class Current: 188/382
• CPC Class Codes: F16H 2059/683 Sensing pressure in control systems or in fluid controlled devices, e.g. by pressure sensors for hydrostatic transmissions F16H2059/6861
• CPC Class Codes: F16H 2061/0209 with independent solenoid valves modulating the pressure individually for each clutch or brake
• CPC Class Codes: F16H 2061/1208 with diagnostic check cycles; Monitoring of failures
• CPC Class Codes: F16H 2061/1224 Adapting to failures or work around with other constraints, e.g. circumvention by avoiding use of failed parts
• CPC Class Codes: F16H 2061/1264 Hydraulic parts of the controller, e.g. a sticking valve or clogged channel
• CPC Class Codes: F16H 2061/1284 the failing part is a sensor
• CPC Class Codes: F16H 59/68 Inputs being a function of gearing status
• CPC Class Codes: F16H 61/12 Detecting malfunction or potential malfunction, e.g. fail safe in control of hydrostatic gearing F16H61/4192; Circumventing or fixing failures
• CPC Class Codes: F16H 61/686 with orbital gears
• CPC Class Codes: Y10S 477/906 Means detecting or ameliorating the effects of malfunction or potential malfunction

Abstract

In an abnormality detecting device and method for a vehicular hydraulic pressure control circuit, which determines an abnormality that has occurred in a hydraulic pressure control circuit including an electromagnetic control valve which generates hydraulic pressure corresponding to a signal supplied from an electronic control unit, and a hydraulic switch which is turned ON when the hydraulic pressure generated by the electromagnetic control valve is equal to or higher than a predetermined value, a power supply of the electronic control unit is kept ON for a predetermined time after an ignition switch is turned from ON to OFF, and an abnormality that has occurred in the hydraulic pressure control circuit is detected within the predetermined time. Thus, it is possible to reliably detect an abnormality that has occurred in the vehicular hydraulic pressure control circuit.

Claims

1. An abnormality detecting device for a vehicular hydraulic pressure control circuit, which detects an abnormality that has occurred in a hydraulic pressure control circuit including an electromagnetic control valve which generates hydraulic pressure corresponding to a signal supplied from an electronic control unit, and a hydraulic switch which is turned ON when the hydraulic pressure generated by the electromagnetic control valve is equal to or higher than a predetermined value, comprising:

a determinator which keeps a power supply of the electronic control unit ON for a predetermined time after an ignition switch is turned from ON to OFF, and which detects an abnormality that has occurred in the hydraulic pressure control circuit based upon a determination made within the predetermined time.

2. The abnormality detecting device for a vehicular hydraulic pressure control circuit, according to claim 1, wherein the determinator determines whether the hydraulic switch is kept ON for the predetermined time, determines that an abnormality has occurred in the hydraulic switch when an affirmative determination is made in the determination, and determines that an abnormality has occurred in an element other than the hydraulic switch in the hydraulic pressure control circuit when a negative determination is made in the determination.

3. The abnormality detecting device for a vehicular hydraulic pressure control circuit, according to claim 2, wherein the determinator determines that an abnormality has occurred in the electromagnetic control valve when a negative determination is made in the determination.

4. The abnormality detecting device for a vehicular hydraulic pressure control circuit, according to claim 2, wherein the determinator determines that an abnormality has occurred in an oil passage between the electromagnetic control valve and the hydraulic switch, when a negative determination is made in the determination.

5. The abnormality detecting device for a vehicular hydraulic pressure control circuit, according to claim 2, wherein the determinator detects an abnormality that has occurred in the hydraulic pressure control circuit, when the hydraulic switch is turned ON in the case where the hydraulic pressure generated by the electromagnetic control valve should be lower than the predetermined value.

6. The abnormality detecting device for a vehicular hydraulic pressure control circuit, according to claim 1, wherein the determinator detects an abnormality that has occurred in the hydraulic pressure control circuit, when the hydraulic switch is turned ON in the case where the hydraulic pressure generated by the electromagnetic control valve should be lower than the predetermined value.

7. An abnormality detecting device for a vehicular hydraulic pressure control circuit, which detects an abnormality that has occurred in a hydraulic pressure control circuit including an electromagnetic control valve which generates hydraulic pressure corresponding to a signal supplied from an electronic control unit, and a hydraulic switch which is turned ON when the hydraulic pressure generated by the electromagnetic control valve is equal to or higher than a predetermined value, comprising:

abnormality detecting means for keeping a power supply of the electronic control unit ON for a predetermined time after an ignition switch is turned from ON to OFF, and for detecting an abnormality that has occurred in the hydraulic pressure control circuit based upon a determination made within the predetermined time.

8. The abnormality detecting device for a vehicular hydraulic pressure control circuit, according to claim 7, wherein the abnormality detecting means includes hydraulic switch abnormality detecting means for determining whether the hydraulic switch is kept ON for the predetermined time, determines that an abnormality has occurred in the hydraulic switch when an affirmative determination is made by the hydraulic switch abnormality detecting means, and determines that an abnormality has occurred in an element other than the hydraulic switch in the hydraulic pressure control circuit when a negative determination is made by the hydraulic switch abnormality detecting means.

9. The abnormality detecting device for a vehicular hydraulic pressure control circuit, according to claim 8, wherein the abnormality detecting means determines that an abnormality has occurred in the electromagnetic control valve, when a negative determination is made by the hydraulic switch abnormality detecting means.

10. The abnormality detecting device for a vehicular hydraulic pressure control circuit, according to claim 8, wherein the abnormality detecting means determines that an abnormality has occurred in an oil passage between the electromagnetic control valve and the hydraulic switch, when a negative determination is made by the hydraulic switch abnormality detecting means.

11. The abnormality detecting device for a vehicular hydraulic pressure control circuit, according to claim 8, characterized in that the abnormality detecting means detects an abnormality that has occurred in the hydraulic pressure control circuit, when the hydraulic switch is turned ON in the case where the hydraulic pressure generated by the electromagnetic control valve should be lower than the predetermined value.

12. The abnormality detecting device for a vehicular hydraulic pressure control circuit, according to claim 7, characterized in that the abnormality detecting means detects an abnormality that has occurred in the hydraulic pressure control circuit, when the hydraulic switch is turned ON in the case where the hydraulic pressure generated by the electromagnetic control valve should be lower than the predetermined value.

13. An abnormality detecting method for a vehicular hydraulic pressure control circuit, for detecting an abnormality that has occurred in a hydraulic pressure control circuit including an electromagnetic control valve which generates hydraulic pressure corresponding to a signal supplied from an electronic control unit, and a hydraulic switch which is turned ON when the hydraulic pressure generated by the electromagnetic is equal to or higher than a predetermined value, comprising the steps of:

keeping a power supply of the electronic control unit ON for a predetermined time after an ignition switch is turned from ON to OFF; and

detecting an abnormality that has occurred in the hydraulic pressure control circuit based upon a determination made within the predetermined time.

14. The abnormality detecting method for a vehicular hydraulic pressure control circuit, according to claim 13, further comprising the following steps of:

determining whether the hydraulic switch is kept ON for the predetermined time;

determining that an abnormality has occurred in the hydraulic switch when an affirmative determination is made in the determination; and

determining that an abnormality has occurred in an element other than the hydraulic switch in the hydraulic pressure control circuit when a negative determination is made in the determination.

15. The abnormality detecting method for a vehicular hydraulic pressure control circuit, according to claim 14, wherein it is determined that an abnormality has occurred in the electromagnetic control valve when a negative determination is made in the determination.

16. The abnormality detecting method for a vehicular hydraulic pressure control circuit, according to claim 14, wherein it is determined that an abnormality has occurred in an oil passage between the electromagnetic control valve and the hydraulic switch, when a negative determination is made in the determination.

17. The abnormality detecting method for a vehicular hydraulic pressure control circuit, according to claim 14, further comprising the step of:

detecting an abnormality that has occurred in the hydraulic pressure control circuit, when the hydraulic switch is turned ON in the case where the hydraulic pressure generated by the electromagnetic control valve should be lower than the predetermined value.

18. The abnormality detecting method for a vehicular hydraulic pressure control circuit, according to claim 13, further comprising the step of:

detecting an abnormality that has occurred in the hydraulic pressure control circuit, when the hydraulic switch is turned ON in the case where the hydraulic pressure generated by the electromagnetic control valve should be lower than the predetermined value.