Apparatus for controlling cooling fan for vehicle

• US 6,603,277 B2
• Filed: 08/22/2001
• Issued: 08/05/2003
• Est. Priority Date: 08/23/2000
• Status: Active Grant

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Yoshimura, Satoshi
• Primary Examiner(s): Fletcher, Marlon T.
• Application Number:
  US09/933,740
• Publication Number:
  US 20020043946A1
• Time in Patent Office: 713 Days
• Field of Search: 318/139-140, 318/146, 318/153, 318/254, 318/280-282, 318/286, 318/439
• US Class Current: 318/139
• CPC Class Codes: H02P 6/24 Arrangements for stopping
• CPC Class Codes: Y02E 10/72 Wind turbines with rotation axis in wind direction

Abstract

A cooling fan control circuit drives a brushless motor to rotate a cooling fan to cool a condenser and a radiator mounted on a vehicle when a drive signal is activated. In a situation where the brushless motor rotates at a rotational speed equal to or higher than a predetermined value by flowing air in a situation that the drive signal is not activated and a charge state signal indicating that a battery is not in a fully charged state, the control circuit turns off MOSFETs in upper arms of an inverter circuit and simultaneously, synchronously switches MOSFETs in lower arms of the inverter circuit. With this configuration, an electric energy generated by the flowing air is stored from the brushless motor to a battery.

Claims

1. An apparatus for controlling a cooling fan for a vehicle, comprising:

a motor for rotating a cooling fan for a vehicle; and

a regenerative apparatus for regenerating electrical energy through the motor in association with rotation of the cooling fan when the cooling fan is rotated by flowing air,

wherein the regenerative apparatus comprises rotational speed detecting means for detecting rotational speed of the motor, and

the regenerative apparatus regenerates the energy through the motor when the rotational speed detected by the rotational speed detecting means is equal to or higher than a predetermined value, while the regenerative apparatus does not regenerate the energy through the motor when the rotational speed detected by the rotational speed detecting means is lower than the predetermined value.

2. The apparatus for controlling the cooling fan for a vehicle according to claim 1, further comprising power storing means capable of storing the electric power,

wherein the regenerative apparatus stores electric energy generated by the motor into the power storing means in a situation that the power storing means is in a non-full stored state.

3. An apparatus for controlling a cooling fan for a vehicle, comprising:

a motor for rotating a cooling fan for a vehicle; and

a driving apparatus for driving the motor to rotate the cooling fan, wherein;

the driving apparatus is constructed to regenerate electrical energy through the motor during rotation of the cooling fan for a vehicle when the cooling fan is rotated by flowing air when the motor is in a non-driven state,

the driving apparatus has rotational speed detecting means for detecting rotational speed of the motor, and

the electric energy is regenerated through the motor when the rotational speed detected by the rotational speed detecting means is equal to or higher than a predetermined value, while the electrical energy is not regenerated by the motor when the rotational speed detected by the rotational speed detecting means is lower than a predetermined value.

4. The apparatus for controlling the cooling fan for a vehicle according to claim 3, further comprising power storing means capable of storing electric power,

wherein the driving apparatus stores energy generated by the motor into the power storing means under the condition that the power storing means is in a non-full stored state.

5. The apparatus for controlling the cooling fan for a vehicle according to claim 4, wherein the motor is a brushless motor.

6. The apparatus for controlling the cooling fan for a vehicle according to claim 5, wherein the driving apparatus comprises:

an inverter circuit constructed by a switching device for switching an application of power to the brushless motor; and

a control circuit for outputting either a drive signal for driving the brushless motor or a regenerative drive signal for regenerating the electric energy by the brushless motor to the switching device.

7. An apparatus for controlling a vehicle cooling fan, comprising:

a brushless motor for rotating the vehicle cooling fan; and

a driving apparatus for driving the brushless motor to rotate the vehicle cooling fan,

wherein the driving apparatus is constructed to regenerate electrical energy by the brushless motor in association with rotation of the vehicle cooling fan when the cooling fan is rotated by flowing air when the brushless motor is in a non-driven state,

the driving apparatus has rotational speed detecting means for detecting rotational speed of the brushless motor, an inverter circuit including a switching device for selectively switching power to the brushless motor; and

a control circuit for outputting either a drive signal for driving the brushless motor or a regenerative drive signal for regenerating the electrical energy through the brushless motor to the switching device,

wherein the electrical energy is regenerated through the brushless motor when the rotational speed detected by the rotational speed detecting means is equal to or higher than a predetermined value, while the electric energy is not regenerated by the brushless motor when the rotational speed detected by the rotational speed detecting means is lower than the predetermined value,

the inverter circuit is a bridge circuit comprising a switching device constituting an upper arm and a switching device on a lower arm, and

the control circuit supplies, as the regenerative drive signal, an off signal to the switching device constituting the upper arm and a switching signal having a predetermined frequency and a predetermined duty ratio to the switching device constituting the lower arm.

8. The apparatus for controlling a cooling fan for a vehicle according to claim 7, further comprising power storing means capable of storing electrical power,

wherein the driving apparatus stores energy generated through the motor into the power storing means when the power storing means is not at full capacity.

9. The apparatus for controlling the cooling fan for a vehicle according to claim 7, wherein the driving apparatus comprises:

an inverter circuit constructed by a switching device for selectively switching power to the brushless motor; and

a control circuit for outputting either a drive signal for driving the brushless motor or a regenerative drive signal for regenerating the electrical energy through the brushless motor to the switching device.

10. A regenerative apparatus for controlling an electrical motor of a cooling fan to operate as a generator, comprising:

a computing circuit for calculating a rotational speed of the cooling fan; and

a driving circuit for driving the electrical motor to rotate the cooling fan and for generating electrical energy through the electrical motor in association with rotation of the cooling fan when the cooling fan is rotated by flowing air when the electrical motor is in a non-driven state;

wherein the driving circuit is controlled for generating electrical energy when the rotational speed calculated by the computing circuit is equal to or higher than a predetermined value, while the driving circuit is not controlled for generating electrical energy when the rotational speed calculated by the computing circuit is lower than the predetermined value.