Failure diagnosis method for dump truck and device therefor

• US 6,175,788 B1
• Filed: 10/05/1998
• Issued: 01/16/2001
• Est. Priority Date: 04/04/1996
• Status: Expired due to Fees

• Current Assignee: Komatsu Ltd.
• Original Assignee: Komatsu Ltd.
• Inventors: Watanabe, Genichirou, Sugano, Yukio, Hasegawa, Nobuki
• Primary Examiner(s): Zanelli, Michael J.
• Application Number:
  US09/155,736
• Time in Patent Office: 834 Days
• Field of Search: 701/50, 701/31, 701/29, 731/172, 731/173
• US Class Current: 701/29
• CPC Class Codes: B60G 17/0185 for failure detection
• CPC Class Codes: B60G 2300/026 Heavy duty trucks
• CPC Class Codes: B60G 2400/25 Stroke; Height; Displacement
• CPC Class Codes: B60G 2400/252 vertical
• CPC Class Codes: B60G 2400/38 Speed of engine rotation
• CPC Class Codes: B60G 2400/50 Pressure
• CPC Class Codes: B60G 2400/70 Temperature of vehicle part or in the vehicle
• CPC Class Codes: B60G 2600/042 Monitoring means
• CPC Class Codes: B60G 2600/08 Failure or malfunction detecting means
• CPC Class Codes: B60G 2600/124 Error signal
• CPC Class Codes: B60G 2800/91 Suspension Control
• CPC Class Codes: B60G 2800/914 Height Control System
• CPC Class Codes: B60G 2800/92 ABS - Brake Control
• CPC Class Codes: B60G 2800/95 Automatic Traction or Slip Control [ATC]
• CPC Class Codes: B60G 2800/97 Engine Management System [EMS]
• CPC Class Codes: B60P 1/045 Levelling or stabilising systems for tippers suspensions with levelling or stabilising means for vehicles in general B60G17/00, B60G21/00, using ground-engaging vehicle fittings B60S9/00
• CPC Class Codes: B60P 1/283 Elements of tipping devices

Abstract

It is possible to prevent generation of failure in a dump truck and to diagnose a true cause of failure in a short period of time. Thus the present failure diagnosis method diagnoses an operation and function of at least one of respective devices, such as an engine at a predetermined engine rotational speed, a transmission, respective axles, respective suspensions, hydro-pneumatic systems, and a brake while a vessel body (4) descends after evacuation of a load. The failure diagnosis device comprises body operating means (50) for raising or lowering a vessel body, a direction switching valve (7) for receiving a command from the body operating means to lower the vessel body, and a self-diagnosis control device (11) for using state detecting means (20) to detect and store a state of at least one of the respective devices at a predetermined engine rotational speed when the body operating means is at a predetermined operative position and for comparing a magnitude of a detected value and a rate of change with reference values on the basis of hysteresis data when carrying out failure diagnosis.

Claims

1. A method for conducting a failure diagnosis for an industrial vehicle having an engine, a transmission, at least one front axle, at least one rear axle, hydraulic systems, a brake, a vessel body, and suspensions for supporting the vessel body, said method comprising the steps of:

lowering said vessel body;

determining a state of at least one device of a group of devices including said engine, said transmission, at least one respective axle, at least one respective suspension, at least one hydraulic system, and said brake, while said vessel body is being lowered and said industrial vehicle is not in motion; and

based on a thus determined state of said at least one device, diagnosing an operation and function of said at least one device.

2. A method in accordance with claim 1, wherein the step of diagnosing comprises diagnosing an operation and function of said engine at a predetermined rotational speed of said engine, while said vessel body is being lowered and said industrial vehicle is not in motion.

3. A method in accordance with claim 1, wherein the step of diagnosing comprises diagnosing an operation and function of said transmission, while said vessel body is being lowered and said industrial vehicle is not in motion.

4. A method in accordance with claim 1, wherein the step of diagnosing comprises diagnosing an operation and function of at least one of said axles, while said vessel body is being lowered and said industrial vehicle is not in motion.

5. A method in accordance with claim 1, wherein the step of diagnosing comprises diagnosing an operation and function of at least one of said suspensions, while said vessel body is being lowered and said industrial vehicle is not in motion.

6. A method in accordance with claim 1, wherein the step of diagnosing comprises diagnosing an operation and function of at least one of said hydraulic systems, while said vessel body is being lowered and said industrial vehicle is not in motion.

7. A method in accordance with claim 1, wherein the step of diagnosing comprises diagnosing an operation and function of said brake, while said vessel body is being lowered and said industrial vehicle is not in motion.

8. A method in accordance with claim 1, wherein the step of diagnosing comprises diagnosing an operation and function of each of:

said engine at a predetermined rotational speed, said transmission, said axles, said suspensions, said hydraulic systems, and said brake, while said vessel body is being lowered and said industrial vehicle is not in motion.

9. A method in accordance with claim 1, wherein the step of determining a state comprises determining at least one of a temperature, a pressure, and a position for at least one of said devices.

10. A method in accordance with claim 1, wherein the step of determining is initiated by said vessel body reaching an end of an ascending operation for unloading said vessel body.

11. A failure diagnosis device for use with an industrial vehicle which has an engine, a transmission, at least one front axle, at least one rear axle, hydraulic systems, a brake, a vessel body, a body operating means, and suspensions for supporting the vessel body, wherein said vessel body can be operated by said body operating means for loading material into said vessel body and for evacuating material from said vessel body, the failure diagnosis device comprising:

state detecting means for detecting a state of at least one device of the group of said engine, said transmission, said axles, said suspensions, said hydraulic systems, and said brake, and for outputting at least one corresponding detected state signal; and

a self-diagnosis control device for inputting said at least one corresponding detected state signal while the body operating means is lowering or floating said vessel body and said industrial vehicle is not in motion, for storing thus inputted detected state signals as hysteresis data, and for comparing (a) a magnitude of a value of said detected state signal and a rate of change with (b) corresponding standard values on a basis of the hysteresis data when carrying out a failure diagnosis of an operation and function of a respective one of said devices.

12. A failure diagnosis device in accordance with claim 11, further comprising body descending start detecting means for detecting a start of a descent of the vessel body;

wherein, when a detection signal from the body descending start detecting means shows a start of a descent of the vessel body and the body operating means is at the descending position or the float position and said industrial vehicle is not in motion, said self-diagnosis control device inputs said at least one corresponding detected state signal, stores said at least one corresponding detected signal as hysteresis data, and compares (a) a magnitude of a value of said corresponding detected state signal and a rate of change with (b) standard values on a basis of the hysteresis data when carrying out failure diagnosis of said operation and function of said respective one of said devices.

13. An industrial vehicle comprising:

an engine;

a transmission;

at least one front axle;

at least one rear axle;

hydraulic systems;

a brake;

a vessel body;

suspensions for supporting the vessel body;

a vessel body operating means wherein said vessel body can be floated or lowered in order to provide for loading material into said vessel body, and raised in order to evacuate material from said vessel body;

state detecting means for detecting a state of at least one device of a group of said engine, said transmission, said axles, said suspensions, said hydraulic systems, and said brake, and for outputting at least one corresponding detected state signal; and

a self-diagnosis control device for inputting said at least one corresponding detected state signal while the vessel body operating means is lowering or floating said vessel body and said industrial vehicle is not in motion, for storing thus inputted detected state signals as hysteresis data, and for comparing (a) a magnitude of a value of said detected state signal and a rate of change with (b) corresponding standard values on a basis of the hysteresis data when carrying out a failure diagnosis of an operation and function of a respective one of said devices.

14. An industrial vehicle in accordance with claim 13, wherein said vessel body operating means comprises means for providing a command to raise, lower, or float said vessel body;

and wherein said industrial vehicle further comprises;

at least one hoist cylinder for raising and lowering said vessel body; and

a direction switching valve for receiving the command from the means for providing to raise, lower, or float the vessel body, and for applying pressurized oil to said at least one hoist cylinder.

15. An industrial vehicle in accordance with claim 13, further comprising body descending start detecting means for detecting a start of a descent of the vessel body;

wherein, when a detection signal from the body descending start detecting means shows a start of a descent of the vessel body, the vessel body operating means is at the descending or float position, and said industrial vehicle is not in motion, said self-diagnosis control device inputs said at least one corresponding detected state signal, stores said at least one corresponding detected signal as hysteresis data, and compares (a) a magnitude of a value of said corresponding detected state signal and a rate of change with (b) standard values on a basis of the hysteresis data when carrying out failure diagnosis of said operation and function of said respective one of said devices.

16. An industrial vehicle in accordance with claim 13, wherein the self-diagnosis control device diagnoses an operation and function of said engine at a predetermined rotational speed of said engine, while said vessel body is being lowered and said industrial vehicle is not in motion.

17. An industrial vehicle in accordance with claim 13, wherein the self-diagnosis control device diagnoses an operation and function of said transmission, while said vessel body is being lowered and said industrial vehicle is not in motion.

18. An industrial vehicle in accordance with claim 13, wherein the self-diagnosis control device diagnoses an operation and function of at least one of said axles, while said vessel body is being lowered and said industrial vehicle is not in motion.

19. An industrial vehicle in accordance with claim 13, wherein the self-diagnosis control device diagnoses an operation and function of at least one of said suspensions, while said vessel body is being lowered and said industrial vehicle is not in motion.

20. An industrial vehicle in accordance with claim 13, wherein the self-diagnosis control device diagnoses an operation and function of at least one of said hydraulic systems, while said vessel body is being lowered and said industrial vehicle is not in motion.

21. An industrial vehicle in accordance with claim 13, wherein the self-diagnosis control device diagnoses an operation and function of said brake, while said vessel body is being lowered and said industrial vehicle is not in motion.

22. An industrial vehicle in accordance with claim 13, wherein the self-diagnosis control device diagnoses an operation and function of each of:

said engine at a predetermined rotational speed, said transmission, said axles, said suspensions, said hydraulic systems, and said brake, while said vessel body is being lowered and said industrial vehicle is not in motion.

23. An industrial vehicle in accordance with claim 13, wherein the state detecting means determines at least one of a temperature, a pressure, and a position for at least one of said devices.

24. An industrial vehicle in accordance with claim 13, further comprising a body ascending end detecting switch, and wherein said self-diagnosis control device is operated by a signal from said body ascending end detecting switch indicating that said vessel body has reached an end of an ascending operation for unloading said vessel body.