JPH092299A - Rear wheel steering angle device - Google Patents

Abstract

(57) [Abstract] [Purpose] By providing a sub motor to the main motor, even if the main motor should fail, the rear wheel steering angle device can obtain a desired function by the sub motor. To provide. [Structure] A shaft having wheels connected to both ends, a casing that accommodates the shaft so as to be movable in the axial direction in a state where rotation is restricted, a nut screwed to a screw portion provided on the shaft, and the casing. The main motor toward the outer circumference of the shaft on one end side of the nut, the clutch mechanism that transmits or shuts off the power of the main motor to the nut, and the outer circumference of the shaft on the other end side of the nut in the casing. A sub motor provided, a clutch mechanism for transmitting or cutting off the power of the sub motor to the nut, and a control mechanism for controlling the main sub motor and the clutch mechanism connected to these motors according to the running state of the vehicle. When the main motor fails, this control mechanism turns on the sub motor and clutches the power of the sub motor. The shaft is moved by transmitting it to the nut through the mechanism and rotating the nut.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rear wheel steering angle device applied to a vehicle, and in particular, it is devised to improve reliability and safety by installing a sub motor separately from a main motor. Regarding what you did.

[0002]

2. Description of the Related Art As a rear wheel steering angle device, there is, for example, one disclosed in Japanese Patent Application Laid-Open No. 63-103763, the construction of which is shown in FIGS. First, there is a bar member 201, and the screw groove 20 is provided on the outer periphery of one end of the bar member 201.
2 are formed. A metal core 203 is fixed to the outer peripheral portion of the rod member 201 near the other end. A plurality of axial grooves 204 are formed on the outer periphery of the rod member 201 on the tip side of the metal core 203.

The rod member 201 is a gear box 205.
At both ends of the gearbox 205 are supported via end guides 208 and 209, and at the same time, a rotation preventing pin 211 that engages with the axial groove 204 is attached to one end of the gearbox 205. The gear box 205 includes a cylindrical case 206 formed by extruding iron and a cast aluminum case 2
It has a configuration that combines 07. The rotation preventing pin 211 is provided at the end of the columnar case 206, and two coils 212, 213 are attached to the inner peripheral portion near the end of the columnar case 206 so that two coils, left and right, are formed inside and outside. Has been.

The coils 212 and 213 are made up of the metal core 2
The steering angle detector 210 of the differential transformer type is formed by facing the outer periphery of 03. A plurality of permanent magnets 2 forming a stator are provided on the inner circumference of the cylindrical case 206.
14 are disposed, and a cylindrical rotor 215 is disposed on the inner peripheral side of these permanent magnets 214 with a gap. The rotor 215 is rotatably supported on the outer periphery of the rod member 201, and has a commutator 218 and a brush 219. Further, as shown in FIG.
Is composed of an iron core 216 and a coil 217,
This constitutes the electric motor 220.

A nut member 222 is fitted in the screw groove 202 of the rod member 201 via a large number of balls 221. The nut member 222 has both ends thereof via the angular ball bearings 223 and 224, the rubber cushions 225 and 226, and the aluminum case 2
It is rotatably supported in 07, thereby constituting a ball screw mechanism 230. A reduction mechanism 240 is inserted between the nut member 222 and the rotor 215, and the reduction mechanism 240 has a sun gear 231 integrally fixed to the rotor 215, and a ring gear 232 integrally fixed to the nut member 222. It is composed of a planetary gear train with a plurality of planet gears 233.

A screw portion 235 is provided on the outer periphery of a ring plate 234 which rotatably supports the planet gear 233.
Is formed on the inner surface of the cylindrical case 203, and the ring gear 232 is fixed to the nut member 22.
It is fixed by being inserted between the bearing 224 and the No. 2 bearing.

[0007]

According to the above-mentioned conventional configuration, there are the following problems. That is, in the conventional rear wheel steering angle device, the motor, that is, the electric motor 220 is
It has a structure provided individually. Therefore, in the unlikely event that the electric motor 220 breaks down due to a motor lock or the like, the operation is stopped midway, and for example, there is a problem that the rear wheels are still being steered. .

The present invention has been made on the basis of such a point. An object of the present invention is to provide a sub motor to the main motor so that even if the main motor should fail, the sub motor can be used. It is an object of the present invention to provide a rear wheel steering angle device that is configured to obtain a desired function and that can regulate a steering angle of rear wheels according to a running state of a vehicle.

[0009]

In order to achieve the above object, a rear wheel steering angle device according to a first aspect of the present invention comprises a shaft having wheels linked to both ends thereof and an axial direction in which the shaft is restricted in rotation. A casing that movably accommodates, a nut that is screwed into a screw portion that is provided on the shaft, a main motor that is provided on the outer peripheral portion of the shaft on one end side of the nut in the casing, and the power of the main motor is transmitted to the nut. A clutch mechanism for opening and closing, a sub-motor provided on the outer peripheral portion of the shaft on the other end side of the nut in the casing, a clutch mechanism for transmitting and disconnecting the power of the sub-motor to the nut, and the running state of the vehicle. Corresponding to the main / sub motor and a clutch mechanism connected to these motors, the control mechanism controlling the clutch mechanism. There as well as on the sub motor when a fault, the sub motor power is transmitted to the nut through a clutch mechanism, having characterized in that the arrangement for moving the shaft to rotate the nut. The second invention is
The first aspect of the present invention is characterized in that a regulation mechanism for regulating the steering angle of the rear wheels is provided according to the traveling state of the vehicle.

[0010]

That is, in the first aspect of the invention, a sub motor is provided separately from the main motor, and if the main motor should fail, the sub motor can be used to steer the rear wheels. For example, when the main motor fails, the main motor is turned off and the sub motor is turned on. Then, the power of the sub motor may be transmitted to the nut via the clutch mechanism to return the rear wheel to the neutral position. In the second aspect of the invention, the steering angle of the rear wheels is regulated by the regulation mechanism, for example, when the vehicle does not require a large steering angle at high speed. Therefore, even if the motor malfunctions, the rear wheels will not be severely cut.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. First, with reference to FIG. 1, there is shown an overall configuration of a vehicle steering system incorporating a rear wheel steering angle device 1 according to the present embodiment. Rear wheels 7 and 9 are connected to both sides of the rear wheel steering angle device 1 via connecting portions 3 and 5, respectively. A front wheel power steering 11 is installed, and front wheels 17 and 19 are connected to both sides of the front wheel power steering 11 via connecting portions 13 and 15, respectively. A steering handle 21 is connected to the front wheel power steering 11, and a vehicle body mounting angle sensor 23 is attached to the steering handle 21.

Further, there is an ECU 25 as a control mechanism,
A necessary power is supplied from the battery 27 to the ECU 25, and a signal is input from the vehicle speed sensor 29. A control signal is output from the ECU 25 to the main motor driver 31, the electromagnetic clutch driver 33, the solenoid driver 35, the electromagnetic clutch driver 37, and the sub motor driver 39. In addition, various signals are exchanged with the rear wheel steering angle device 1.

Next, the structure of the rear wheel steering angle device 1 will be described with reference to FIGS. First, there is a casing 51, and a shaft 53 is concentrically arranged in the casing 51. A ball screw 55 is formed at a position slightly left of the center position of the shaft 53.
A ball nut 57 is screwed onto the ball screw 55 via a plurality of balls 59. By rotating the ball nut 57 in an appropriate direction, the shaft 53 moves to either the left or right direction in FIG. 2 via the ball screw 55, whereby the rear wheels 7, 9 are moved.
This is to adjust the steering angle of.

A stopper mechanism 61 is installed on the outer peripheral side of the ball nut 57. This stopper mechanism 61
Is composed of a solenoid 63 and a stopper pin 65 connected to the solenoid 63. By appropriately driving the solenoid 63 and fitting the stopper pin 65 into the recess 67 of the ball nut 57, The rotation of the ball nut 57 is restricted.

On the left side of the ball nut 57 in FIG.
A main motor 69 is installed. The main motor 69 includes a stator 7 fixed to the inner peripheral surface of the casing 51.
1, a rotor 75 rotatably arranged on the outer peripheral side of the shaft 53 via a bearing 73, a commutator 77, and a brush 7
9 and so on. An electromagnetic clutch 81 and a speed reducer 83 are inserted between the main motor 69 and the ball nut 57.

On the other hand, a sub motor 85 is installed on the right side of the ball nut 57 in FIG. The sub-motor 85 includes a stator 8 fixed to the inner peripheral surface of the casing 51.
7, a rotor 91 rotatably arranged on the outer peripheral side of the shaft 53 via a bearing 89, a commutator 93, and a brush 9
It is composed of 5 etc. An electromagnetic clutch 97 and a speed reducer 99 are inserted between the sub motor 85 and the ball nut 57.

A steering angle sensor 101 is mounted on the right side of the sub motor 85 in FIG.
It is in communication with the shaft 53 side through 3. In the figure, reference numeral 105 is a bearing, reference numerals 107 and 109 are bearings, reference numeral 111 is a bearing, and reference numeral 113 is a rotation stopper of the shaft 53.

The operation will be described based on the above configuration. First, when the small steering angle is at a high speed, the solenoid 63 is excited and the stopper pin 65 is fitted into the recess 67 of the ball nut 57 to restrict the rotation of the ball nut 57, thereby restricting the movement of the shaft 53. I am trying. Therefore, even if the motor malfunctions, the rear wheels 7 and 9 will not be severely cut off. On the other hand, at the time of large steering angle at low speed, the solenoid 63 is de-excited and the stopper pin 65 is recessed in the ball nut 57. It is removed from 67 to allow the rotation of the ball nut 57. And
Under the control of the ECU 25, the main motor 69 is driven to rotate the ball nut 57 appropriately. Thereby, the shaft 53 moves in an appropriate direction by an appropriate amount,
Steer the rear wheels 7, 9. In addition, these stopper pins 65
The concave portion 67 and the concave portion 67 constitute a regulation mechanism.

If the main motor 69 should fail, the ECU 25 turns off the main motor 69 and turns off the electromagnetic clutch 81 on the main motor 69 side. Then, the power of the sub motor 85 is turned on and the electromagnetic clutch 97 on the side of the sub motor 85 is turned on. As a result, the rotation is transmitted from the sub motor 85 to the ball nut 57, whereby
The shaft 53 is returned to the neutral position. The steering angle sensor 101
Detects the amount of axial movement of the shaft 53 by
It feeds back to CU25.

[0020]

As described in detail above, according to the rear wheel steering angle device according to the first aspect of the invention, a sub motor is provided separately from the main motor, and if the main motor should fail, the sub motor is driven to Since the wheels can be steered, the reliability is greatly improved and the situation where the rear wheels are left in the steered state can be eliminated. According to the second aspect of the invention, even if the motor malfunctions, the rear wheel is not severely cut.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of the present invention and is a diagram showing a configuration of a vehicle steering system incorporating a rear wheel steering angle device.

FIG. 2 is a sectional view showing a configuration of a rear wheel steering angle device, which is a diagram showing an embodiment of the present invention.

3 is a view showing an embodiment of the present invention and is a sectional view taken along line III-III in FIG.

FIG. 4 is a sectional view taken along line IV-IV of FIG. 2 showing an embodiment of the present invention.

5 is a view showing an embodiment of the present invention and is a view taken in the direction of the arrow V in FIG.

FIG. 6 is a cross-sectional view of a rear wheel steering angle device showing a conventional example.

7 is a view showing a conventional example and is a VII-VII sectional view of FIG. 6. FIG.

[Explanation of symbols]

 1 Rear Wheel Steering Angle Device 7 Rear Wheel 9 Rear Wheel 25 ECU (Control Mechanism) 51 Casing 53 Shaft 55 Ball Screw (Screw Part) 57 Ball Nut (Nut) 69 Main Motor 81 Electromagnetic Clutch (Clutch Mechanism) 85 Sub Motor 97 Electromagnetic Clutch ( Clutch mechanism)

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[Procedure amendment]

[Submission date] July 24, 1995

[Procedure amendment 1]

[Document name to be amended] Drawing

[Correction target item name] Fig. 1

[Correction method] Change

[Correction contents]

FIG.

Claims (2)

[Claims] 1. A shaft having wheels connected to both ends thereof, a casing that accommodates the shaft so as to be movable in the axial direction in a state where rotation of the shaft is restricted, and a nut screwed to a screw portion provided on the shaft. A main motor provided on the outer peripheral portion of the shaft on one end side of the nut in the casing, a clutch mechanism for transmitting or cutting off the power of the main motor to the nut, and an outer periphery of the shaft on the other end side of the nut in the casing. And a clutch mechanism for transmitting or cutting off the power of the sub motor to the nut, and a control mechanism for controlling the main sub motor and the clutch mechanism connected to these motors according to the running state of the vehicle. This control mechanism turns on the sub motor when the main motor fails, and also controls the power of the sub motor. Transmission to the nut via the switch mechanism,
A rear wheel steering angle device characterized in that a nut is rotated to move a shaft. 2. The rear wheel steering system according to claim 1, further comprising a restricting mechanism for restricting a steering angle of the rear wheels according to a running state of the vehicle.