Drive device

Patent metadata

Field	Value
Publication number	US-10640059-B2
Application number	US-201615570482-A
Country	US
Kind code	B2
Filing date	Jul 7, 2016
Priority date	Jul 8, 2015
Publication date	May 5, 2020
Grant date	May 5, 2020

Abstract

A drive device includes: a first current path that has a high-side MOSFET; a second current path that has a low-side MOSFET; and a third current path connected to the other end portion of a coil and positioned between the first current path and the second current path. The drive device further includes: PWM drive circuits that generate a drive signal through PWM control; and an overcurrent detection circuit that detects that an overcurrent has flowed through the current paths. It is possible to precisely detect the occurrence of a battery short circuit and a ground short circuit by detecting which of the first current path and the second current path an overcurrent has flowed through.

First claim

The invention claimed is:

1. A drive device connected to a solenoid valve, one end portion of a coil of which is connected to a ground that is continuous with a negative electrode side of a battery and which is drivably controlled in accordance with a drive signal input to the other end portion of the coil, the drive device comprising:
a first current path that has a high-side switching element connected to a positive electrode side of the battery;
a second current path that has a low-side switching element connected to a ground that is continuous with the negative electrode side of the battery;
a third current path connected to the other end portion of the coil and positioned between the first current path and the second current path;
a drive unit that supplies a control signal to each of the high-side switching element and the low-side switching element and that performs control so as to generate the drive signal by alternately switching the first current path and the third current path, and the second current path and the third current path, between a conductive state and a non-conductive state;
an overcurrent detection unit that detects that an overcurrent that exceeds a value of a current that flows during normal supply of the drive signal has flowed through the first current path and the second current path; and
a control unit that executes determination processing in which occurrence of a ground short circuit at a voltage lower than a normal operation range of the solenoid valve is determined in the case where the overcurrent detection unit detects that the overcurrent has flowed through the first current path, and in which occurrence of a battery short circuit at a voltage higher than the normal operation range of the solenoid valve is determined in the case where the overcurrent detection unit detects that the overcurrent has flowed through the second current path.

2. The drive device according to claim 1 , wherein:
the high-side switching element and the low-side switching element are constituted from a high-side transistor and a low-side transistor of the same conductivity type;
the drive device further comprises a first determination transistor and a second determination transistor of the same conductivity type as the high-side transistor and the low-side transistor;
a signal input electrode of the high-side transistor is connected to the drive unit, and one end of a current path of the high-side transistor is connected to the positive electrode side of the battery;
a signal input electrode of the low-side transistor is connected to the drive unit, and one end of a current path of the low-side transistor is connected to the ground;
a signal input electrode of the first determination transistor is connected to the drive unit, and one end of a current path of the first determination transistor is connected to a point in the first current path between the high-side transistor and a positive electrode of the battery;
a signal input electrode of the second determination transistor is connected to the drive unit, and one end of a current path of the second determination transistor is connected to a point in the second current path between the one end of the current path of the low-side transistor and the ground; and
the other end of each of the current paths of the first determination transistor and the second determination transistor is connected to the overcurrent detection unit.

3. The drive device according to claim 2 , wherein
the high-side transistor, the low-side transistor, the first determination transistor, and the second determination transistor are constituted from an N-channel or P-channel MOSFET of an enhancement type, or an N-channel or P-channel MISFET of an enhancement type.

4. The drive device according to claim 1 , further comprising:
a current detection unit that detects a current that flows through the coil by way of the third current path, wherein
the control unit executes wire breakage determination processing for determining a wire breakage state, in which the solenoid valve is electrically disconnected, in the case where the current which flows through the third current path is no longer detected by the current detection unit.

5. The drive device according to claim 4 , wherein:
the high-side switching element and the low-side switching element are constituted from a high-side transistor and a low-side transistor of the same conductivity type;
the drive device further comprises a first determination transistor and a second determination transistor of the same conductivity type as the high-side transistor and the low-side transistor;
a signal input electrode of the high-side transistor is connected to the drive unit, and one end of a current path of the high-side transistor is connected to the positive electrode side of the battery;
a signal input electrode of the low-side transistor is connected to the drive unit, and one end of a current path of the low-side transistor is connected to the ground;
a signal input electrode of the first determination transistor is connected to the drive unit, and one end of a current path of the first determination transistor is connected to a point in the first current path between the high-side transistor and a positive electrode of the battery;
a signal input electrode of the second determination transistor is connected to the drive unit, and one end of a current path of the second determination transistor is connected to a point in the second current path between the one end of the current path of the low-side transistor and the ground; and
the other end of each of the current paths of the first determination transistor and the second determination transistor is connected to the overcurrent detection unit.

6. The drive device according to claim 5 , wherein
the high-side transistor, the low-side transistor, the first determination transistor, and the second determination transistor are constituted from an N-channel or P-channel MOSFET of an enhancement type, or an N-channel or P-channel MISFET of an enhancement type.

7. The drive device according to claim 1 , wherein:
the high-side switching element and the low-side switching element are constituted from a high-side transistor and a low-side transistor of the same conductivity type;
the drive device further comprises a first determination transistor and a second determination transistor of the same conductivity type as the high-side transistor and the low-side transistor;
a signal input electrode of the high-side transistor is connected to the drive unit, and one end of a current path of the high-side transistor is connected to the positive electrode side of the battery;
a signal input electrode of the low-side transistor is connected to the drive unit, and one end of a current path of the low-side transistor is connected to the ground;
a signal input electrode of the first determination transistor is connected to the drive unit, and one end of a current path of the first determination transistor is connected to a point in the first current path between the high-side transistor and a positive electrode of the battery;
a signal input electrode of the second determination transistor is connected to the drive unit, and one end of a current path of the second determination transistor is connected to a point in the second current path between the one end of the current path of the low-side transistor and the ground; and
the other end of each of the current paths of the first determination transistor and the second determination transistor is connected to the overcurrent detection unit.

8. The drive device according to claim 7 , wherein
the high-side transistor, the low-side transistor, the first determination tra

Assignees

• Aisin Aw Co

Inventors

• Yamashita Kento

Classifications

• B60R16/02

  electric {constitutive elements} · CPC title

• H01F2007/1888

  using pulse width modulation · CPC title

• F16H61/421

  Motor capacity control by electro-hydraulic control means, e.g. using solenoid valves · CPC title

• F02D2041/2093

  detecting short circuits · CPC title

• H03K17/0822

  in field-effect transistor switches · CPC title