Control apparatus for electric oil pump

• US 9,039,383 B2
• Filed: 09/11/2012
• Issued: 05/26/2015
• Est. Priority Date: 09/22/2011
• Status: Active Grant

• Current Assignee: Hitachi Astemo Ltd. (Hitachi, Ltd.)
• Original Assignee: Hitachi Automotive Systems Limited (Hitachi, Ltd.)
• Inventors: Okamoto, Naoki
• Primary Examiner(s): COMLEY, ALEXANDER BRYANT
• Application Number:
  US13/610,216
• Publication Number:
  US 20130078111A1
• Time in Patent Office: 987 Days
• Field of Search: 417/13, 417/14, 417/32, 417/281, 417/364, 417/426, 475/137
• US Class Current: 417/32
• CPC Class Codes: F04B 2205/10 Inlet temperature
• CPC Class Codes: F04B 2205/11 Outlet temperature
• CPC Class Codes: F04B 49/02 Stopping, starting, unloading or idling control
• CPC Class Codes: F04B 49/06 Control using electricity regulating by means of floats actuating electric switches F04B49/04
• CPC Class Codes: F16H 2061/1208 with diagnostic check cycles; Monitoring of failures
• CPC Class Codes: F16H 2312/14 Going to, or coming from standby operation, e.g. for engine start-stop operation at traffic lights
• CPC Class Codes: F16H 59/72 dependent on oil characteristics, e.g. temperature, viscosity
• CPC Class Codes: F16H 61/0031 using auxiliary pumps, e.g. pump driven by a different power source than the engine

Abstract

A temperature range in which an electric oil pump to supply oil to a vehicle drive system can start is enlarged to enhance an effective use degree, enhance a start success probability, and suppress malfunction occurrence. When a measured oil temperature To is in a temperature range (T1≦To<T2) in which it is not clear whether or not the electric oil pump normally operates, a trial operation is performed with a drive current limited as compared with a regular operation and a target rotation number No while malfunction determination is invalid (a non-established state) (S1→S6), when a rotation number which is not smaller than predetermined rotation number No cannot be achieved, pump driving is stopped (S9, 14), and when the rotation number is achieved, the malfunction determination is allowed (S11), and the pump is driven according to an instruction (S12).

Claims

1. A control apparatus of an electric oil pump which supplies oil to a vehicle drive system, comprising:

an oil temperature measuring section which measures an oil temperature;

a trial operation control section which performs a trial operation in a state in which a drive current of the electric oil pump is limited to be less than a required drive current of the electric oil pump, and performs the trial operation in a state in which the trial operation control section does not establish a malfunction determination of the electric oil pump when the measured oil temperature is in a temperature range in which operation of the electric oil pump is susceptible to measurement error due to a fluctuation of the oil temperature measuring section; and

a regular operation allowing determining section which allows a regular operation of the electric oil pump while allowing the malfunction determination of a main body of the electric oil pump when a rotation number increasing state of the electric oil pump subjected to the trial operation satisfies a regular operation allowing condition, and which stops driving of the electric oil pump when the rotation number increasing state does not satisfy the regular operation allowing condition.

2. The control apparatus of the electric oil pump according to claim 1, further comprising:

a first pump control section which drives the electric oil pump according to a request, when the oil temperature measured after turning on a drive power supply is not lower than a second temperature; and

a second pump control section which does not allow the driving of the electric oil pump, when the measured oil temperature is lower than a first temperature that is lower than the second temperature,

wherein the trial operation control section forcibly drives the electric oil pump while limiting a drive current by use of a limited predetermined rotation number as a target value irrespective of whether the pump operation is requested in the state in which the malfunction determination of the electric oil pump is not established, when the measured oil temperature is not lower than the first temperature and is lower than the second temperature, and

the regular operation allowing determining section stops the driving of the electric oil pump, when the predetermined rotation number cannot be reached by the forcible driving, and allows the malfunction determination of a main body of the electric oil pump and drives the electric oil pump according to the request, when the predetermined rotation number is reachable.

3. The control apparatus of the electric oil pump according to claim 2,

wherein the regular operation allowing determining section forcibly drives the electric oil pump again while limiting a drive current by use of the predetermined rotation number as the target value so as to judge whether or not the predetermined rotation number is reached when the measured oil temperature rises to a temperature which is higher than the first temperature by a predetermined temperature, in a case in which the predetermined rotation number cannot be reached and the driving of the electric oil pump is stopped,

wherein the predetermined temperature is lower than the second temperature.

4. The control apparatus of the electric oil pump according to claim 3,

wherein the regular operation allowing determining section allows the malfunction determination of the main body of the electric oil pump, and drives the electric oil pump according to the request, when the measured oil temperature reaches the second temperature in a case in which the predetermined rotation number cannot be reached and the driving of the electric oil pump is stopped.

5. The control apparatus of the electric oil pump according to claim 2, further comprising:

a learning control section which forcibly drives the electric oil pump while limiting a drive current by use of the predetermined rotation number as a target value, stores the oil temperature measured at the time as a learning value when the predetermined rotation number is reached, and controls a start of the electric oil pump based on the learning value of the oil temperature.

6. The control apparatus of the electric oil pump according to claim 1,

wherein a drive instruction of the electric oil pump is performed by an external controller, and the electric oil pump operates according to the drive instruction,

wherein the control apparatus further comprises:

a determining section which determines whether or not the operation of the electric oil pump is possible according to the drive instruction;

a judgment transmitting section which operates the electric oil pump according to the drive instruction when the determining section determines that the operation is possible, stops the operation of the electric oil pump without performing the malfunction determination when the determining section determines that the operation is not possible, and transmits judgment of an inability to operate to the external controller; and

a malfunction judging section which judges the malfunction of the electric oil pump based on at least oil temperature information in the external controller.

7. The control apparatus of the electric oil pump according to claim 1,

wherein the electric oil pump is configured to generate a hydraulic pressure of a transmission of an idle stop car.

8. The control apparatus of the electric oil pump according to claim 1,

wherein the electric oil pump is configured to cool a running electric motor or an inverter of a hybrid car.

9. A control apparatus of an electric oil pump which supplies oil to a vehicle drive system, comprising:

oil temperature measuring means for measuring an oil temperature;

trial operation control means for performing a trial operation in a state in which a drive current of the electric oil pump is limited to be less than a required drive current of the electric oil pump and in a state where the trial operation control means does not establish a malfunction determination of the electric oil pump when the measured oil temperature is in a temperature range in which operation of the electric oil pump is susceptible to measurement error due to a fluctuation of the oil temperature measuring means; and

regular operation allowing determining means for allowing a regular operation of the electric oil pump while allowing the malfunction determination of a main body of the electric oil pump when a rotation number increasing state of the electric oil pump subjected to the trial operation satisfies a regular operation allowing condition, and for stopping driving of the electric oil pump when the rotation number increasing state does not satisfy the regular operation allowing condition.