JPH0534192B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a power steering device that changes the steering force of the power steering by electronic control in response to vehicle speed, steering speed, or steering angle, and particularly relates to a power steering device that changes the steering force of the power steering in response to vehicle speed, steering speed, or steering angle. The present invention relates to a power steering device that can turn on a warning lamp to indicate a system abnormality in the event of a failure.

[Prior art]

An example of a conventional electronically controlled power steering device is shown in FIG.

In FIG. 1, 1 is a controller, which has a built-in microcomputer 2 as a control means,
Vehicle speed sensor 3 for microcomputer 2
The vehicle speed detected by the steering angle sensor 4 and the steering angle detected by the steering angle sensor 4 are input, and the microcomputer 2 further detects the steering angle speed by differentiating the detected steering angle. Taking vehicle speed sensitive control as an example, the microcomputer 2 A control output that provides a light steering force at low speeds and increases the steering force as the vehicle speed increases is supplied to an actuator of a power steering drive unit (not shown), thereby controlling the steering force in response to vehicle speed.

On the other hand, the microcomputer 2 is equipped with an alarm function that notifies the driver of an abnormality when a system failure such as a disconnection of the vehicle speed sensor 3 is detected.
The transistor 6 is turned on by an alarm output due to abnormality detection, and an alarm lamp 7 connected to the collector of the transistor 6 is turned on.

Power is supplied to the controller 1 and the alarm lamp 7 having such a configuration by using the same power system for the output of the battery 8 via the ignition switch 9 and the power fuse 10.

[Problem that the invention seeks to solve]

However, in such a conventional power steering device, power is supplied to the controller 1 and the alarm lamp 7 through the power fuse 10 of the same system, so if the power fuse 10 blows due to a circuit short or the like, In this case, the power supply to the controller 1 and the alarm lamp 7 is stopped at the same time, and the alarm cannot be displayed by lighting the alarm lamp, even though the power supply route failure is also one of the system abnormalities.
For this reason, even if the control stops due to a power supply outage, the warning lamp does not light up, so the driver has no choice but to assume that the system is operating normally, and is forced to respond to speed with a fail-safe operation based on a failure in the power supply path. Since the control switches from a fixed steering force control to a fixed steering force that is in the middle of the variable range of steering force, for example, when the vehicle is stationary at low speed, an abnormality can be detected when the steering force becomes heavier than normal. There was a problem in that there was a delay in noticing system abnormalities.

The present invention has been made in view of these conventional problems, and is designed to ensure that even if the power supply to the controller is stopped, an alarm of system abnormality can be displayed as long as the power supply to the alarm lamp is not stopped. The purpose of the present invention is to provide a power steering device that has the following features.

[Structure of the invention]

To achieve this object, the present invention provides a power steering device that changes steering force in response to at least one of vehicle speed, steering speed, or steering angle, including a battery power source 8 and a battery power source 8.
An alarm lamp 7 is connected to the power steering device at one end, and an alarm lamp 7 is connected to the other end to indicate an abnormality in the power steering device.
and a microcomputer 2 that outputs a lighting signal when determining that there is an abnormality in the power steering device.
Ignition switch 9 connects the
A fuse 13 is interposed between the ignition switch 9 and the microcomputer 2 so as to be parallel to the alarm lamp 7, and a fuse 13 is connected between the alarm lamp 7 and the ground and connected to the microcomputer 2. 2, and when the lighting signal from the microcomputer 2 is input, the first driving means 6 grounds the earth side connection end of the alarm lamp 7 and lights the alarm lamp 7; When the lamp 7 and the earth are connected in parallel to the first driving means 6 and also connected to the fuse 13, and the driving voltage is supplied from the battery power source 8 via the fuse 13, A second method for lighting the alarm lamp 7 by grounding the ground side connection end of the alarm lamp 7 when the ground side connection end of the alarm lamp 7 is not grounded and no driving voltage is supplied from the battery power source 8. The driving means 15 or 17 and 18 are provided.

Further, as the second driving means, the relay 1
Automatic switch circuit using transistor 5 or transistor 1
An automatic switch circuit using circuits 7 and 18 is preferred.

〔Example〕

FIG. 2 is a circuit block diagram showing one embodiment of the present invention.

First, to explain the configuration, reference numeral 1 is a controller, which has a built-in microcomputer 2 having a power steering control program.A vehicle speed sensor 3 and a steering angle sensor 4 are connected as inputs to the microcomputer 2. The steering force is controlled in response to the angle and further to the steering angular velocity obtained by differentiating the detected steering angle. In addition, the microcomputer 2 detects malfunctions such as power supply abnormalities and sensor abnormalities and displays an alarm, and also stops controlling the steering force in response to vehicle speed, etc., and adjusts the steering force to an intermediate value within the variable range of the steering force. An abnormality handling program is built in to perform fail-safe operation to fix the problem. The base of a transistor 6, which is the first driving means of the alarm lamp, is connected to the alarm output port based on the abnormality processing program built in the microcomputer 2, and the collector of the transistor 6 is connected to an alarm output port that outputs an alarm based on the abnormality processing program built into the microcomputer 2. A lamp 7 is connected, and the warning lamp 7 is installed at a position easily visible to the driver, such as on an instrument panel.

Next, explaining the power supply system, 8 is a battery, and the power supply voltage of the battery 8 is applied to an ignition switch 9.

A warning lamp 7 and a controller 1 are connected to the battery non-connected terminal of the ignition switch 9.
and a built-in microcomputer 2 are connected in parallel via a power supply fuse 12 and a power supply fuse 13, respectively.

The power fuse 12 is interposed between the ignition switch 9 and the alarm lamp 7 in parallel with the power fuse 13.

The power supply fuse 13 is interposed between the ignition switch 9 and the microcomputer 2 in parallel with the alarm lamp 7.

In this embodiment, when the power supply to the controller 1 is stopped, the earth side connection end of the alarm lamp 7 is grounded to turn on the alarm lamp 7.
The invention is characterized in that an automatic switch circuit (alarm lamp lighting circuit) using a relay is provided as the driving means (emergency lighting means).

That is, there is a power fuse 1 in the controller 1.
A relay 15 having a relay coil 15a supplied with battery voltage from 3 is provided as a second driving means, and the relay 15 has a normally closed contact 15b with a protective resistor 16 connected in series. are connected in parallel between the collector and emitter of transistor 6.

The operation of the embodiment of FIG.
2 and 13 are normal, the relay coil 1 of the relay 15 receives power from the power fuse 13.
5a is energized and opens the normally closed contact 15b,
The alarm lamp 7 can be turned on by turning on the transistor 6 based on the output of the microcomputer 2.

On the other hand, when the power fuse 13 installed in the system that supplies power to the controller 1 melts,
The relay coil 15a of the relay 15 is deenergized and the normally closed contact 15b is closed, and a current determined by the protective resistor 16 flows from the fuse 12 through the alarm lamp 7 and the normally closed contact 15b to the automatic switch circuit using the relay. , the alarm lamp 7 is lit.

FIG. 3 is a circuit block diagram showing another embodiment of the present invention, and this embodiment is characterized in that the automatic switch circuit using relays in the embodiment of FIG. 2 is made into a transistor.

That is, the system from the power supply fuse 13 to the microcomputer 2 in the controller 1 is branched midway, and the branch line is connected to the base of the transistor 17 via the resistor R1, and the collector of the transistor 17 is connected to the transistor 18 in the next stage. The collector of the transistor 18 is connected to the alarm lamp 7 side via the protective resistor 16 to form a second driving means, and the base of the transistor 18 is connected to the power supply from the alarm lamp 7 side. A bias circuit consisting of a resistor R2 and a resistor R3 connected in series is provided to form an automatic switch circuit using transistors.

The operation of the embodiment of FIG.
When the transistors 2 and 13 are normal, the transistor 17 is turned on by receiving battery voltage through the power supply fuse 13, and when the transistor 17 is turned on, the base of the transistor 18 is pulled to zero volts and cut off, and the microcomputer 2 is turned on. The alarm lamp 7 can be turned on by turning on the transistor 6 based on the output of the alarm lamp 7.

On the other hand, if the power supply fuse 13 is blown,
The base voltage of the transistor 17 decreases, turning off the transistor 17, turning on the transistor 18 due to the bias provided by the resistors R2 and R3, a current determined by the protective resistor 16 flows through the alarm lamp 7, and the alarm lamp 7 is turned on.

〔Effect of the invention〕

As described above, according to the present invention, in a power steering device whose configuration changes the steering force in response to at least one of vehicle speed, steering speed, or steering angle, the battery power source 8 and the battery power source 8 are connected to each other. One end is connected to the ignition, and the other end is connected in parallel with an alarm lamp 7 that displays an abnormality in the power steering device and a microcomputer 2 that outputs a lighting signal when it determines that there is an abnormality in the power steering device. switch 9; a fuse 13 interposed between the ignition switch 9 and the microcomputer 2 so as to be parallel to the alarm lamp 7; a first driving means 6 that is connected to a microcomputer 2 and that, when the lighting signal from the microcomputer 2 is input, grounds the earth side connection end of the alarm lamp 7 and lights the alarm lamp 7; When the alarm lamp 7 and the ground are connected in parallel to the first driving means 6 and also connected to the fuse 13, and a driving voltage is supplied from the battery power source 8 via the fuse 13. Do not ground the earth side connection end of the alarm lamp 7,
A second driving means 15, or 17, 18 is provided for lighting the alarm lamp 7 by grounding the earth side connection end of the alarm lamp 7 when a driving voltage is not supplied from the battery power source 8. Even if a power failure occurs due to disconnection of the power fuse 13 that supplies power to the microcomputer 2 side, power is supplied to the alarm lamp 7 normally, and the second driving means 15 or 17, 18 An abnormality in the power steering system can be indicated by lighting the warning lamp 7 based on a power abnormality, and the driver can confirm that the power steering system has an abnormality and the steering force is not sensitive to vehicle speed, etc. in the variable range. It is possible to confirm that the vehicle has switched to fail-safe operation, which is the intermediate value, and after the warning lamp 7 lights up, the vehicle can be brought to a maintenance shop or the like for inspection and repair while paying careful attention to the steering wheel operation. .

[Brief explanation of the drawing]

Figure 1 is a circuit block diagram showing a conventional example, Figure 2 is a circuit block diagram showing a conventional example.
The figure is a circuit block diagram showing one embodiment of the present invention.
FIG. 3 is a circuit block diagram showing another embodiment of the present invention. 1... Controller, 2... Microcomputer, 3... Vehicle speed sensor, 4... Rudder angle sensor, 6, 1
7, 18...transistor, 7...alarm lamp, 8...
Battery (battery power supply), 9...Ignition switch, 12, 13...Power fuse, 15
...Relay, 15a...Relay coil, 15b...Normally closed contact, 16...Protection resistor.

Claims (1)

[Claims] 1. A power steering device that changes steering force in response to at least one of vehicle speed, steering speed, or steering angle, comprising: a battery power source 8 connected to one end and connected to the other end; an ignition switch 9 that connects in parallel an alarm lamp 7 that displays an abnormality in the power steering device and a microcomputer 2 that outputs a lighting signal when it determines that there is an abnormality in the power steering device; A fuse 13 is interposed between the ignition switch 9 and the microcomputer 2 so as to be in parallel with the alarm lamp 7; a first driving means 6 that connects and lights up the alarm lamp 7 by grounding the earth side connection end of the alarm lamp 7 when the lighting signal from the microcomputer 2 is input; and ground in parallel to the first driving means 6 and to the fuse 13, and when the driving voltage is supplied from the battery power source 8 via the fuse 13, the alarm is activated. a second drive means that does not ground the earth side connection end of the lamp 7 and lights up the alarm lamp 7 by grounding the earth side connection end of the alarm lamp 7 when no driving voltage is supplied from the battery power source 8; 15 or 17, 18
A power steering device characterized by comprising: 2. The power steering device according to claim 1, further comprising an automatic switch circuit using a relay 15 as the second driving means. 3 Transistor 1 as the second driving means
The power steering device according to claim 1, further comprising an automatic switch circuit using switches 7 and 18.