JPH01153379A - Steering device - Google Patents

Abstract

PURPOSE:To prevent the vibration of a steering handle by providing the steering handle mechanically separated from a steering mechanism with springs to energize the handle to its neutral position and a damper to generate damping force through fluid viscosity. CONSTITUTION:A reaction force generating device has two torsion springs 22a, 22b and a damper 23. The springs 22a, 22b are locked to a collar 24 fixed to a steering shaft 15 on its one end and to holders 25a, 25b fixed to a body B on its other end respectively. The steering shaft 15 is kept by the torsion springs at the neutral position of a steering handle 11. The damper 23 is composed of a hollow housing 26 into which a hub spindle 27 uniting with the steering shaft 15 is rotatably inserted through bearings 28a, 28b. The housing 26 is sealingly filled with highly viscous fluid, which generates damping force according to a difference in relative rotation between a housing plate 32 and a hub plate 33.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a steering device in which a steering wheel and a steering wheel are mechanically separated. The present invention relates to a steering device that improves the steering feel of a steering wheel by providing a spring element that biases the steering wheel toward a neutral position and a damping element that applies a resistance force using the viscosity of a fluid.

(Prior art) A steering device in which the steering wheel and the steering wheel are not mechanically connected is often used in special vehicles such as tractors because the steering wheel and steering mechanism can be separated, allowing for greater freedom in layout. ing. This type of steering device was developed in 1986-43.
As described in Japanese Patent No. 473, a steering mechanical system operated by an electric motor is provided for each of the front wheels and the rear wheels, and a steering wheel is supported on the vehicle body, and the support section is provided with a steering system that applies steering resistance to the steering wheel. A force actuator is provided to detect the operation of the steering wheel and drive and control the steering mechanical system based on the detected signal. This steering system uses a DC motor as a reaction force actuator, and controls the DC motor to generate a reaction force proportional to the square of the vehicle speed V (φy2), thereby imparting steering resistance to the operation of the steering wheel.

(Problem to be solved by this invention) However,
In the above-mentioned steering device, since the steering resistance is applied by a DC motor, the control becomes complicated in order to provide a sensual index to the neutral position of the steering wheel.
There was a problem in that in order to drive the motor, measures such as increasing the battery capacity were required.

On the other hand, in order to solve the above-mentioned problems, it is conceivable to install a spring that biases the steering wheel toward the neutral position. The problem arises that the ring is damaged.

This invention has been made in view of the above-mentioned problems, and provides a steering wheel that provides a sensual indicator for the neutral position of the steering wheel and improves the convergence of the steering wheel without impairing the steering feel. The purpose is to provide equipment.

(Means for Solving the Problems) The present invention provides a steering device that electrically detects the operation of a steering wheel and drives steering wheels with an actuator based on this detection signal. The gist is to include a spring element that urges the steering wheel to a neutral position, and a damping element that applies a resistance force to the steering wheel depending on the steering speed using fluid viscous resistance.

(Function) According to the steering device according to the present invention, the spring element biases the steering handle to the neutral position to provide a sensory indicator, and the damping element damps vibrations of the steering handle.
A good steering feeling can be obtained. The damping element generates a damping force according to the steering speed of the steering wheel and applies the damping force as a steering resistance force, so that the steering wheel and the steering wheel are mechanically connected to each other. Approximate steering reaction force can be obtained.

(Example) Embodiments of the present invention will be described below based on the drawings.

1 to 4 show a steering device according to an embodiment of the present invention, in which FIG. 1 is a general schematic diagram, FIG. 2 is a schematic perspective view of a mechanical part, and FIG. 3 is a sectional view of a main part. FIG. 4 is a hydraulic circuit diagram.

In FIGS. 1 and 2, 11 is a steering handle;
2 is a front wheel steering mechanism that steers left and right front wheels 14FL and 14FR, and 13 is a left and right rear wheel 14RL.

This is a rear wheel steering mechanism that steers the 14RR, and these steering handles 11, front wheel steering mechanism 12, and rear wheel steering mechanism 13
are mechanically separated and independent from each other.

The steering handle 11 is fixed to the upper end of a steering shaft 15, and the steering shaft 15 is rotatably supported by a bracket 16 on the vehicle body. The steering shaft 15 is provided with an encoder 17 and a tacho generator 18 at its intermediate portion, and a reaction force generator 19 at its lower end. The encoder 17 is a gear mechanism 20
The tacho generator 18 is connected to the steering shaft 15 via a gear mechanism 20 to detect the steering angle, and similarly, the tacho generator 18 is connected to the steering shaft 15 via a gear mechanism 20 to detect the steering speed. The encoder 17 and the tachometer generator 18 are connected to a control unit 21, the encoder 17 outputs a detection signal representing the steering angle to the control unit 21, and the tachometer generator 18 outputs a detection signal representing the steering speed to the control unit 21.

As shown in detail in FIG. 3, the reaction force generator 19 includes two torsion springs (spring elements) 22a.

22b and a damper (damping element) 23. Torsion springs 22a and 22b (represented by numbers without subscripts) have one end engaged with a collar 24 fixed to the steering shaft 15 and the other end engaged with holders 25a and 25b fixed to the vehicle body B, respectively. and urges the steering shaft 15 to the neutral position of the steering handle 11.

The damper 23 is a hollow housing 2 fixed to the vehicle body B.
A hub shaft 27 integral with the steering shaft 15 is rotatably inserted through bearings 28a and 28b. The opening of the housing 26 is liquid-tightly closed by a cap 29 to define a chamber 26a in which a highly viscous fluid such as silicone oil is sealed. Communication is provided via a nipple 31 provided. In this housing 26, a plurality of housing plates 32 are movable in the axial direction and fixed in the rotational direction by serration coupling or the like on the inner wall of a chamber 26a, and similarly, a plurality of hub plates 33 are attached to the hub shaft 27 in the axial direction. The movable and rotationally fixed plates 32, 33 are arranged axially alternatingly.

34 is a suberi, and the suberi 34 is the hub plate 3
3 to maintain the axial spacing between the hub plates 33. This damper 23 generates a damping force according to the relative rotational speed difference between the housing plate 32 and the hub plate 33 due to the viscosity of the fluid, and this damping force changes by changing the fluid filling rate in the chamber 26a.

In the front wheel steering mechanism 12, a rod 36 is supported by a box 35 so as to be slidable in the vehicle width direction, and an electric motor (not shown) connected to the control unit 21 is provided in the box 35 coaxially with the rod 36. The output shaft is connected to the rod 36 via a transmission mechanism such as a pole nut mechanism so as to be capable of transmitting power. The rod 36 has knuckles 37FL at both ends of the left and right front wheels 14FL and 14FR.

Connected to 37FR, these front wheels are 14FL.

The 14FR is driven by an electric motor and steered. Further, the box 35 is provided with a steering angle sensor 38F that detects the axial displacement of the rod 36, that is, the front wheel steering angle, and this steering angle sensor 38F is connected to the control unit 21. Similarly, the rear wheel steering mechanism 13 also includes an electric motor connected to the control unit 21 in the box 35,
Knuckle 37R with left and right rear wheels 14RL and 14RR on both ends
A rod 36 connected to L and 37RR is driven by an electric motor to steer the rear wheels 14RL and 14RR, and a steering angle sensor 38R detects the steering angles of the rear wheels 14RL and 14RR. Although the front wheel steering mechanism 12 and the rear wheel steering mechanism 13 have the same basic configuration, the front wheel steering mechanism 12 has a larger output and stroke than the rear wheel steering mechanism 13.

The control unit 21 includes a control circuit composed of a microcomputer, a drive circuit that energizes the electric motor of the steering mechanism 12, 13, etc. based on the output signal of the control circuit, a filling rate regulator 30, and the like. The aforementioned encoder 17, tachogenerator 18, and steering angle sensors 3BF, 38R are connected to the control circuit, and vehicle speed sensors 40FL, 40FR are provided on each of the front, rear, left, and right wheels 14FL, 14FR, 14RL, and 14RR.

40RL, 40RR, a lateral acceleration sensor 41, and a yaw acceleration sensor 42 are connected. Vehicle speed sensor 40 (
(represented by a number without a subscript) detects the vehicle speed and outputs a signal representing the vehicle speed to the control circuit, and similarly, the lateral acceleration sensor 4
1 outputs a signal representing lateral acceleration to the control circuit, and yaw acceleration sensor 42 outputs a signal representing yaw acceleration to the control circuit. The control circuit processes input signals using a microcomputer to determine control values such as target steering angle and steering force for the front wheels and rear wheels, respectively, and outputs control signals representing these control values to the drive circuit. The drive circuit! I
Input from I# circuit! The electric motor of the front wheel steering mechanism 12 and the electric motor of the rear wheel steering mechanism 13 are energized based on the II# signal.

The filling rate regulator 30 is connected to a motor 43 as shown in FIG.
A pump 44 driven by pressurizes and discharges oil in a reservoir tank 45, and the pressure oil discharged by the pump 44 is stored in an accumulator 46, and a center-closed electromagnetic control valve 47 is controlled by the aforementioned control circuit. to the conversion cylinder 48 via. The motor 43 is connected to the drive circuit, the accumulator 46 is provided with a pressure sensor 49 connected to the control circuit, and the motor 43 is driven when the oil pressure in the accumulator 46 drops below a predetermined value based on the output signal of the pressure sensor 49. be done.

In the conversion cylinder 48, a free piston 48b is slidably fitted into a cylinder body 48a, and the chamber 2 of the damper 23 is
A chamber 50a connected to the valve 6a and a chamber 50b connected to the electromagnetic control valve 47 are separated from each other. This conversion cylinder 48
The free piston 48b slides according to the pressure inside the chamber 50b to increase or decrease the volume of the chamber 50a, and the chamber 50a and the damper 2
The fluid filling rate of the chamber 26a of the damper 23 is adjusted by flowing fluid between the chamber 26a of the damper 23 and the chamber 26a of the damper 23.

Next, the operation of this embodiment will be explained.

This steering device includes a steering handle 11 and a front wheel steering mechanism 12.
and the rear wheel steering mechanism 13 are mechanically separated, and detect the operation angle of the steering handle 11, steering speed, vehicle speed, lateral acceleration, yaw acceleration, etc., and based on this steering information, the front and rear wheels 14FL, 14FR, respectively. , 14RL, 14R
Controls R's rudder angle, steering force, etc.

On the other hand, in this steering device, the steering handle 1 is
1 to provide steering resistance, torsion spring 22a,
The damper 22b generates a restoring force toward the neutral position to provide a sensory indicator of the neutral position, and the damper 23 generates a damping force approximately proportional to the steering speed as shown by the solid line in FIG. Attenuates vibrations of the handle 11. Therefore, the vibration of the steering handle 11 is suppressed and stabilized, and a good steering feeling can be obtained. In this steering system, the damper 23 exhibits characteristics as shown by the chain line in FIG. 5 depending on the filling rate of the viscous fluid, that is, the amount of viscous fluid in the chamber 26a. Control proportionally. Therefore, the damping force generated by the damper 23 increases at high speeds, and the damping force generated by the damper 23 decreases at low speeds, resulting in a better steering feeling.

(Effects of the Invention) As explained above, according to the steering device according to the present invention, a damper that generates a damping force by fluid viscosity is used together with a spring that biases the steering handle mechanically separated from the steering mechanism to the neutral position. Because of the provision of the steering wheel, vibration of the steering wheel can be suppressed and convergence can be improved, resulting in a good steering feel.

In particular, in the embodiment, the filling rate of the viscous fluid in the damper is controlled approximately proportionally to the vehicle speed to increase the damping force at high speeds, so a better steering feeling can be obtained.

[Brief explanation of the drawing]

1 to 5 show a steering device according to an embodiment of the present invention, in which FIG. 1 is a general schematic diagram, FIG. 2 is a schematic perspective view of a mechanical part, and FIG. 3 is a sectional view of a main part. FIG. 4 is a hydraulic circuit diagram, and FIG. 5 is a characteristic diagram. 11... Steering handle 12... Front wheel steering mechanism 13... Rear wheel steering mechanism 14FL, 14FR... Front wheels 14RL, 14RR... Rear wheel 17... Encoder 18... Tacho generator 19... - Reaction force generator 21... Control unit 22a, 22b... Torsion spring (spring element) 23... Damper (damping element) 30... Filling rate adjuster 38F, 38R... Rudder angle sensor 40...・Vehicle speed sensor 41...Lateral acceleration sensor 42...Yaw acceleration Patent applicant: Agent for Honda Motor Co., Ltd.
Patent Attorney Part 2 1) Yong-Immediate Question Patent Attorney
Kuni Ohashi Otoma Patent Attorney
Yama Yuyuki Patent Attorney No 1)
Shigeru Figure 4 Figure 5 Operation w - False Farming

Claims (1)

[Scope of Claims] A steering device that electrically detects the operation of a steering wheel and drives steering wheels using an actuator based on this detection signal to urge the steering wheel to a neutral position. A steering device comprising: a spring element; and a damping element that uses fluid viscous resistance to apply a resistance force to a steering wheel according to its steering speed.