Drive circuit anomaly diagnosing device

Patent metadata

Field	Value
Publication number	US-11203245-B2
Application number	US-201816491384-A
Country	US
Kind code	B2
Filing date	Jul 13, 2018
Priority date	Jul 26, 2017
Publication date	Dec 21, 2021
Grant date	Dec 21, 2021

Abstract

A drive circuit anomaly diagnosing device of the present invention performs an anomaly diagnosis on a drive circuit including a power supply line on which a solenoid is disposed midway, a main switch disposed on the power source side relative to the solenoid, a first diode disposed on a protection line connecting a point between the main switch and the solenoid to ground with a forward direction corresponding to a direction from the ground side to the power source side, and a first capacitor interposed on a first line connecting a point between the protection line and the solenoid to the ground midway on the power supply line, the drive circuit being configured to supply power to the solenoid, on the basis of a current detected by a first current sensor disposed upstream of the main switch on the power supply line.

First claim

The invention claimed is:

1. A drive circuit anomaly diagnosing device for a drive circuit, the drive circuit including a power supply line on which a solenoid is disposed midway, the power supply line connecting a power source to ground, a main switch disposed on the power source side relative to the solenoid midway on the power supply line, a protection line connecting a point between the main switch and the solenoid to the ground, a first diode disposed midway on the protection line with a forward direction corresponding to a direction from the ground side to the power source side, and a first capacitor interposed on a first line connecting one end on the power source side of the solenoid to the ground midway on the power supply line, the drive circuit being configured to supply power to the solenoid, the drive circuit anomaly diagnosing device comprising:
a first current sensor configured to detect a current upstream of the main switch midway on the power supply line, and
a second current sensor configured to detect a current flowing from a connection point with the protection line to the solenoid midway on the power supply line, wherein
the drive circuit includes a second capacitor interposed on a second line connecting the other end on the ground side of the solenoid to the ground midway on the power supply line, a demagnetizing switch disposed between the solenoid and the ground midway on the power supply line, a demagnetization line connecting a point between the main switch and the power source to a point between the solenoid and the demagnetizing switch midway on the power supply line, and a second diode disposed midway on the demagnetization line with a forward direction corresponding to the direction from the ground side to the power source side,
the drive circuit anomaly diagnosing device comprises a third current sensor configured to detect a current between the second line and the demagnetizing switch midway on the power supply line or a temperature sensor configured to detect a temperature of the demagnetizing switch, and
the drive circuit anomaly diagnosing device detects an anomaly of the drive circuit on the basis of the currents detected by the first current sensor and the second current sensor, and the current detected by the third current sensor or the temperature detected by the temperature sensor.

2. The drive circuit anomaly diagnosing device according to claim 1 , comprising
a voltage sensor configured to detect a voltage between the second line and the demagnetizing switch midway on the power supply line, wherein
the drive circuit anomaly diagnosing device detects an anomaly of the drive circuit on the basis of the currents detected by the first current sensor and the second current sensor, the current detected by the third current sensor or the temperature detected by the temperature sensor, and the voltage detected by the voltage sensor.

3. The drive circuit anomaly diagnosing device according to claim 2 , wherein
the drive circuit anomaly diagnosing device diagnoses the second capacitor or the solenoid as having an anomaly when the voltage detected by the voltage sensor is lower than a voltage threshold during demagnetization.

4. The drive circuit anomaly diagnosing device according to claim 1 , wherein
the drive circuit anomaly diagnosing device diagnoses the first diode or the second diode as having an anomaly when the current detected by the first current sensor is equal to or higher than a first current threshold and the current detected by the second current sensor is lower than a second current threshold.

5. The drive circuit anomaly diagnosing device according to claim 4 , wherein
the drive circuit includes a fail switch disposed on the power source side relative to the main switch on the power supply line, and
the drive circuit anomaly diagnosing device turns off the fail switch when the current detected by the first current sensor is equal to or higher than a short-circuit current threshold larger than the first current threshold.

6. A drive circuit anomaly diagnosing device for a drive circuit, the drive circuit including a power supply line on which a solenoid is disposed midway, the power supply line connecting a power source to ground, a main switch disposed on the power source side relative to the solenoid midway on the power supply line, a protection line connecting a point between the main switch and the solenoid to the ground, a first diode disposed midway on the protection line with a forward direction corresponding to a direction from the ground side to the power source side, and a first capacitor interposed on a first line connecting one end on the power source side of the solenoid to the ground midway on the power supply line, the drive circuit being configured to supply power to the solenoid, the drive circuit anomaly diagnosing device comprising:
a first current sensor configured to detect a current upstream of the main switch midway on the power supply line,
a second current sensor configured to detect a current flowing from a connection point with the protection line to the solenoid midway on the power supply line, wherein
the drive circuit anomaly diagnosing device diagnoses the first capacitor, the solenoid, or the main switch as having an anomaly when the current detected by the first current sensor is equal to or higher than a first current threshold and the current detected by the second current sensor is equal to or higher than a second current threshold.

Assignees

• Kyb Corp

Inventors

• Kojima Hiroyuki
• Awano Koichiro

Classifications

• B60G17/0185 Primary

  for failure detection · CPC title

• H01F7/1811

  demagnetising upon switching off, removing residual magnetism · CPC title

• B60G17/06

  Characteristics of dampers {, e.g. mechanical dampers}(B60G17/015 takes precedence) · CPC title

• H03K17/0812

  by measures taken in the control circuit · CPC title

• B60G2600/08

  Failure or malfunction detecting means · CPC title