Electric power steering apparatus

Patent metadata

Field	Value
Publication number	US-10752283-B2
Application number	US-201616303830-A
Country	US
Kind code	B2
Filing date	Sep 5, 2016
Priority date	Sep 5, 2016
Publication date	Aug 25, 2020
Grant date	Aug 25, 2020

Abstract

Two sets of independent armature windings and two sets of control units are provided; a single power-source connector branches into at least four lines in the vicinity of a power-source terminal; a power source relay, a filter, and an inverter circuit are connected, in that order, with a line where a large current flows; a control circuit unit is connected with a line where a small current flows and a detection circuit for detecting an abnormality in the control circuit unit is provided in that line.

First claim

The invention claimed is:

1. An electric power steering apparatus comprising:
an electric motor that produces assist torque, based on steering torque produced by a driver of a vehicle;
a controller that controls the electric motor; and
a power-source connector that is connected with a battery mounted in the vehicle and supplies respective power sources to the controller and the electric motor,
wherein the electric motor is provided with two sets of armature windings including a first armature winding and a second armature winding that are formed in substantially the same manner,
wherein the controller is formed of two sets of controllers that are formed in substantially the same manner and that include a first controller formed in such a way as to be capable of independently controlling the first armature winding and a second controller formed in such a way as to be capable of independently controlling the second armature winding,
wherein each of the first controller and the second controller has
a power source relay formed in such a way as to be capable of turning on/off a power source,
a filter circuit connected with the power source relay,
an input circuit to which information from a sensor is inputted,
a driving circuit that generates a driving signal for driving the electric motor,
an inverter circuit that is controlled by the driving signal, and
a control circuit provided with a CPU that outputs to the driving circuit a command signal for controlling the electric motor based on the information inputted to the input circuit,

wherein the power-source connector is formed of a single connector,
wherein out of terminals of the power-source connector, a power source system to be connected at least with the positive-polarity side of the battery branches into two lines in the immediate vicinity of the terminals; one of the branch lines is connected with the first controller and the other one of the branch lines is connected with the second controller,
wherein each of the two branch lines further re-branches into two lines,
wherein the power source relay, the filter circuit, and the inverter circuit are connected with one of the re-branch lines, and
wherein the control circuit is connected with the other one of the re-branch lines by way of a first detection circuit that detects an abnormality in a circuit connected with the control circuit.

2. The electric power steering apparatus according to claim 1 , wherein in the case where a current flowing in the other one of the re-branch lines exceeds a predetermined range, which is preliminarily set, the first detection circuit in the controller stops a function of the control circuit connected with the other one of the re-branch lines and notifies the CPU of the stoppage.

3. The electric power steering apparatus according to claim 2 , further including a second detection circuit that detects a current flowing in the one of the re-branch lines, wherein in the case where the current detected by the second detection circuit is larger than a predetermined value, which is preliminarily set, the power source relay is made to operate so as to cut off the one of the re-branch lines.

4. The electric power steering apparatus according to claim 3 , further including a third detection circuit that detects a current flowing at the downstream side of the filter circuit in the one of the re-branch lines, wherein in the case where the current flowing at the downstream side of the filter circuit, detected by the third detection circuit, is larger than a predetermined value, which is preliminarily set, the power source relay is made to operate so as to cut off the one of the re-branch lines.

5. The electric power steering apparatus according to claim 4 ,
wherein the third detection circuit is formed in such a way as to detect not the current but a voltage at a position at the downstream side of and immediately after the filter circuit or a voltage to be supplied to the inverter circuit, and
wherein in the case where the voltage at a position at the downstream side of and immediately after the filter circuit or the voltage to be supplied to the inverter circuit, detected by the third detection circuit, is larger than a predetermined value, which is preliminarily set, the power source relay is made to operate so as to cut off the one of the re-branch lines.

6. The electric power steering apparatus according to claim 2 , further including a third detection circuit that detects a current flowing at the downstream side of the filter circuit in the one of the re-branch lines, wherein in the case where the current flowing at the downstream side of the filter circuit, detected by the third detection circuit, is larger than a predetermined value, which is preliminarily set, the power source relay is made to operate so as to cut off the one of the re-branch lines.

7. The electric power steering apparatus according to claim 6 ,
wherein the third detection circuit is formed in such a way as to detect not the current but a voltage at a position at the downstream side of and immediately after the filter circuit or a voltage to be supplied to the inverter circuit, and
wherein in the case where the voltage at a position at the downstream side of and immediately after the filter circuit or the voltage to be supplied to the inverter circuit, detected by the third detection circuit, is larger than a predetermined value, which is preliminarily set, the power source relay is made to operate so as to cut off the one of the re-branch lines.

8. The electric power steering apparatus according to claim 2 , further including a fourth detection circuit that detects a current to be supplied from the inverter circuit to the armature winding of the electric motor or a voltage at a winding terminal of the armature winding of the electric motor, wherein in the case where the current to be supplied to the armature winding of the electric motor or the voltage at a winding terminal of the armature winding of the electric motor, detected by the fourth detection circuit, is larger than a predetermined value, which is preliminarily set, the power source relay is made to operate so as to cut off the one of the re-branch lines.

9. The electric power steering apparatus according to claim 2 ,
wherein the electric motor and the controller are arranged concentrically with each other in the axle direction,
wherein the power-source connector is disposed at the axle-direction end portion, at the anti-electric-motor side, of the controller,
wherein at a position in the axle-direction vicinity of the position where the power-source connector is disposed, the power source relay, the first detection circuit, and the filter circuit are arranged in the controller, and
wherein the CPU and the inverter circuit are arranged at the electric-motor side of the power source relay, the first detection circuit, and the filter circuit.

10. The electric power steering apparatus according to claim 1 , further including a second detection circuit that detects a current flowing in the one of the re-branch lines, wherein in the case where the current detected by the second detection circuit is larger than a predetermined value, which is preliminarily set, the power source relay is made to operate so as to cut off the one of the re-branch lines.

11. The electric power steering apparatus according to claim 10 , further including a third detection circuit that detects a current flowing at the downstream side of the filter circuit in the one of the re-branch lines, wherein in the case where the current flowing at the downstream side of the filter circuit, detected by the third detection circuit, is larger than a predeterm

Assignees

• Mitsubishi Electric Corp

Inventors

• Nagashima Tomohiko
• Mori Akihiko

Classifications

• B62D5/0403 Primary

  characterised by constructional features, e.g. common housing for motor and gear box · CPC title

• H02P29/0241

  the fault being an overvoltage · CPC title

• H02P29/025

  the fault being a power interruption · CPC title

• B62D5/0487 Primary

  detecting motor faults (B62D5/0496 takes precedence) · CPC title

• H02K11/33

  Drive circuits, e.g. power electronics (H02K11/38 takes precedence) · CPC title