Diagnosis apparatus for air transfer apparatus and method thereof

• US 20050089407A1
• Filed: 09/17/2004
• Published: 04/28/2005
• Est. Priority Date: 09/22/2003
• Status: Active Grant

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi Unisia Automotive, Ltd. (Hitachi, Ltd.)
• Inventors: Hosoya, Hajime
• Granted Patent: US 7,121,137 B2
• Time in Patent Office: Days
• US Class Current: 417/63
• CPC Class Codes: F02M 25/0818 having means for pressurising the evaporative emission space

Abstract

An air pump is driven under a condition where a check valve is not opened, and an occurrence of failure in the check valve and the air pump is diagnosed based on a driving load of the air pump or a pressure upstream of the check valve or a pressure downstream of the check valve at the time.

Claims

1. A diagnosis apparatus for an air transfer apparatus which includes an air pump transferring air to a shielded section and a check valve disposed in a transfer passage between said shielded section and said air pump, comprising:

a drive unit that drives said air pump under a condition where said check valve is held in a closed state;

a transfer state detector detecting a transfer state of the air by said air pump; and

a diagnosis unit that diagnoses whether or not a failure occurred in said air transfer apparatus based on the transfer state of the air detected by said transfer state detector, when said air pump is driven by said drive unit.

2. A diagnosis apparatus for an air transfer apparatus according to claim 1, wherein said transfer state detector detects a driving load of said air pump.

3. A diagnosis apparatus for an air transfer apparatus according to claim 2,

wherein said diagnosis unit judges an occurrence of failure in said air pump, when the driving load of said air pump is less than a lower limit value and when the driving load of said air pump exceeds an upper limit value.

4. A diagnosis apparatus for an air transfer apparatus according to claim 1,

wherein said transfer state detector detects a pressure in the transfer passage between said air pump and said check valve.

5. A diagnosis apparatus for an air transfer apparatus according to claim 4,

wherein said diagnosis unit judges the occurrence of failure in said air transfer apparatus, in the case where the pressure in the transfer passage between said air pump and said check valve is not changed up to a predetermined pressure.

6. A diagnosis apparatus for an air transfer apparatus according to claim 1,

wherein said transfer state detector detects a pressure in said shielded section.

7. A diagnosis apparatus for an air transfer apparatus according to claim 6,

wherein said diagnosis unit judges an occurrence of failure in said check valve, in the case where the pressure in said shielded section is changed in synchronism with the drive of said air pump.

8. A diagnosis apparatus for an air transfer apparatus according to claim 1,

wherein said transfer state detector detects a pressure in the transfer passage between said air pump and said check valve, and also detects a pressure in said shielded section, and

said diagnosis unit:

judges whether or not the pressure in said shielded section is changed in synchronism with the drive of said air pump, when the pressure in the transfer passage between said air pump and said check valve is not changed up to a predetermined pressure;

judges an occurrence of failure in said check valve, when the pressure in said shielded section is changed in synchronism with the drive of said air pump; and

judges an occurrence of failure in said air pump, when the pressure in said shielded section is not changed in synchronism with the drive of said air pump.

9. A diagnosis apparatus for an air transfer apparatus according to claim 1,

wherein said drive unit drives said air pump, so that the air is transferred in a reverse direction to an airflow direction in said check valve.

10. A diagnosis apparatus for an air transfer apparatus according to claim 1,

wherein said drive unit drives said air pump, so that the air is transferred in a direction same as an airflow direction in said check valve, and also a primary side pressure of said check valve does not reach a valve opening pressure.

11. A diagnosis apparatus for an air transfer apparatus according to claim 1,

wherein said check valve includes:

a resilient body applying on a valve body an urging force for valve closing which is equal to or larger than a maximum generated pressure by said air pump; and

an actuator generating a valve opening force against the urging force for valve closing by said resilient body.

12. A diagnosis apparatus for an air transfer apparatus according to claim 11,

wherein said drive unit stops the generation of the valve opening force by said actuator, to establish a condition where said check valve is held in the closed state.

13. A diagnosis apparatus for an air transfer apparatus according to claim 12,

wherein said drive unit switches the generation/stop of valve opening force by said actuator, and

said diagnosis unit diagnoses the occurrence of failure in said air transfer apparatus based on a change in said transfer state with the switching of the generation/stop of valve opening force by said actuator.

14. A diagnosis apparatus for an air transfer apparatus which includes air transfer means for transferring air to a shielded section and check means disposed in a transfer passage between said shielded section and said air transfer means, comprising:

drive means for driving said air transfer means under a condition where said check means is held in a closed state;

transfer state detecting means for detecting a transfer state of the air by said air transfer means; and

diagnosis means for diagnosing whether or not a failure occurred in said air transfer apparatus based on the transfer state of the air detected by said transfer state detecting means, when said air transfer means is driven by said drive means.

15. A diagnosis method for an air transfer apparatus which includes an air pump transferring air to a shielded section and a check valve disposed in a transfer passage between said shielded section and said air pump, comprising the steps of:

driving said air pump under a condition where said check valve is held in a closed state;

detecting a transfer state of the air by said air pump; and

diagnosing whether or not a failure occurred in said air transfer apparatus based on the transfer state of the air.

16. A diagnosis method for an air transfer apparatus according to claim 15,

wherein said step of detecting the transfer state detects a driving load of said air pump.

17. A diagnosis method for an air transfer apparatus according to claim 16,

wherein said step of diagnosing the occurrence of failure comprises the steps of:

judging an occurrence of failure in said air pump, when the driving load of said air pump is less than a lower limit value; and

judging the occurrence of failure in said air pump, when the driving load of said air pump exceeds an upper limit value.

18. A diagnosis method for an air transfer apparatus according to claim 15,

wherein said step of detecting the transfer state comprises the step of;

detecting a pressure in the transfer passage between said air pump and said check valve.

19. A diagnosis method for an air transfer apparatus according to claim 18,

wherein said step of diagnosing the occurrence of failure comprises the step of;

judging the occurrence of failure in said air transfer apparatus, in the case where the pressure in the transfer passage between said air pump and said check valve is not changed up to a predetermined pressure.

20. A diagnosis method for an air transfer apparatus according to claim 15,

wherein said step of detecting the transfer state comprises the step of;

detecting a pressure in said shielded section.

21. A diagnosis method for an air transfer apparatus according to claim 20,

wherein said step of diagnosing the occurrence of failure comprises the step of;

judging an occurrence of failure in said check valve, in the case where the pressure in said shielded section is changed in synchronism with the drive of said air pump.

22. A diagnosis method for an air transfer apparatus according to claim 15,

wherein said step of detecting the transfer state comprises the steps of:

detecting a pressure in the transfer passage between said air pump and said check valve; and

detecting a pressure in said shielded section, and

said step of diagnosing the occurrence of failure comprises the steps of;

judging whether or not the pressure in said shielded section is changed in synchronism with the drive of said air pump, when the pressure in the transfer passage between said air pump and said check valve is not changed up to a predetermined pressure;

judging an occurrence of failure in said check valve, when the pressure in said shielded section is changed in synchronism with the drive of said air pump; and

judging an occurrence of failure in said air pump, when the pressure in said shielded section is not changed in synchronism with the drive of said air pump.

23. A diagnosis method for an air transfer apparatus according to claim 15,

wherein said step of driving the air pump comprises the step of;

driving said air pump, so that the air is transferred in a reverse direction to an airflow direction in said check valve.

24. A diagnosis method for an air transfer apparatus according to claim 15,

wherein said step of driving the air pump comprises the step of;

driving said air pump, so that the air is transferred in a direction same as an airflow direction in said check valve, and also a primary side pressure of said check valve does not reach a valve opening pressure.

25. A diagnosis method for an air transfer apparatus according to claim 15,

wherein said check valve includes:

a resilient body applying on a valve body an urging force for valve closing which is equal to or larger than a maximum generated pressure by said air pump; and

an actuator generating a valve opening force against the urging force for valve closing by said resilient body.

26. A diagnosis method for an air transfer apparatus according to claim 25,

wherein said step of driving the air pump comprises the step of;

stopping the generation of the valve opening force by said actuator, to establish a condition where said check valve is held in the closed state.

27. A diagnosis method for an air transfer apparatus according to claim 26,

wherein said step of driving the air pump comprises the step of;

switching the generation/stop of valve opening force by said actuator, and

said step of diagnosing the occurrence of failure comprises the step of;

diagnosing the occurrence of failure in said air transfer apparatus based on a change in said transfer state with the switching of the generation/stop of valve opening force by said actuator.