JPH02147469A - Starting method for motor-driven power steering - Google Patents

Abstract

PURPOSE:To provide smooth assist start at a low cost by engaging a clutch first in case there has already been torque input when power is put on,and by increasing the assist amount gradually with a certain time cast in with respect to the torque input. CONSTITUTION:When a driver puts the power on, a clutch 14 is fully engaged. Then the torque of a motor 11 is increased gradually in accordance with the value from a torque sensor 12, to slowly attain the assist proper. When prefect correspondence with the amount of the assist proper is obtained, transition is made into normal control. Thus smooth continuance is accomplished easily with simple structure by means of increasing the assist amount gradually at starting, which enhances the reliability and suppresses the cost for the clutch construction to a great extent.

Description

DETAILED DESCRIPTION OF THE INVENTION FIELD OF INDUSTRIAL APPLICATION The present invention relates to a method for starting an electric power steering device for an automobile.

Conventional technology Recently, electric power steering has been announced as a new power steering system, but due to safety concerns, the motor that assists steering and the steering shaft are connected by a clutch, and in abnormal conditions, the clutch is disconnected and the steering shaft is It is constructed so that it can be steered only from the side. This clutch is disconnected before the power is turned on, so it must be connected when the power is turned on.

Below, while referring to the drawing, is the clutch engaged and steering? The process up to the start of +i-suke will be explained.

FIG. 2 is a flowchart at the time of conventional startup, and FIG. 3 is a schematic configuration diagram of an electric power steering system.

First, when the control circuit unit 16 is powered on by the driver's actions such as starting the engine, the torque sensor 1
Assist is started by the output from 2. The control circuit section 16 controls the torque of the motor 11 based on the output value of the torque sensor 12.

Problems to be Solved by the Invention However, in the above method, if the driver has his hands on the steering wheel when turning on the power, in order to reduce the discomfort and start assisting smoothly, the clutch connection force is increased. It is necessary to control the clutch, and as a result, the clutch is used with slipping, so when considering the durability of the clutch, there is a problem that the use of slipping material increases costs and complicates the structure. Was.

In view of the above-mentioned drawbacks, the present invention provides a smooth initiation of assist at a low cost.

Means to Solve the Problems In order to solve the above problems, the starting method of the present invention is that if there is already a torque input when the power is turned on, the clutch is first engaged, and the torque input is gradually assisted over a certain period of time. This is a method to smoothly start υt1 by increasing the amount.

Operation The present invention can simplify the clutch structure at low cost and with high reliability by the method described above.

EXAMPLES Hereinafter, examples of the present invention will be described with reference to the drawings.

FIG. 1 shows a flowchart at startup. Now, when the driver turns on the power, the clutch is fully engaged.

After that, the motor torque is gradually increased according to the value from the torque sensor, and the torque is slowly increased to the original assist level. When the amount of assist completely matches the original amount, the control shifts to normal control.

In addition to the effects of the invention, the present invention gradually increases the amount of assist at startup, thereby making it possible to easily achieve a smooth connection with a simple structure, thereby improving reliability. I can go down.

[Brief explanation of the drawing]

FIG. 1 is a flowchart showing a method of starting electric power steering according to the present invention, FIG. 2 is a flowchart showing a conventional starting method, and FIG. 3 is a schematic diagram of the configuration of electric power steering. 11... Motor, 12... Torque sensor, 13... Steering shaft, 14...
Clutch, 15... Handle, 16...
Control circuit section. Name of agent: Patent attorney Shigetaka Awano (1 person) Figure 1 Figure 2

Claims (1)

[Claims] A torque sensor that outputs steering force is installed between the steering shaft and the wheels, and an auxiliary motor that assists in steering.
In an electric power steering device having a clutch that connects the output of the motor to the steering shaft and a control circuit unit that controls the amount of steering, the electric power steering device increases the amount of steering at a certain slope when the power is turned on. How to start.