JPH0622151U - Power steering system - Google Patents

Abstract

(57) [Abstract] [Purpose] In a power steering system including a steering gear that transmits rotation of a steering wheel, a linkage that steers a tire in association with the steering gear, and a motor that power assists movement of the linkage. While ensuring the fail-safe mechanism, that is, manual steering of the tire when the motor and its control means fail, vibration of the tire is transmitted from the linkage to the steering wheel side of the vehicle compartment through the steering gear during normal operation. Prevent. [Structure] Means 29, 3 for detecting rotation of the handle 20
0, a motor control means 50 for driving the motor 25 in accordance with the rotation of the steering wheel 20, an electromagnetic clutch mechanism 38 for connecting and disconnecting the rotation transmission from the steering wheel 20 to the steering gear 31 side, and this clutch mechanism 38 for driving the motor. A clutch control means 50 is provided for energizing and disconnecting the solenoid 48 when the control system 35 and its control system are normal, and for disconnecting and energizing the solenoid 48 when an abnormality occurs. The steering reaction force is applied to the steering wheel 2 when the clutch mechanism 38 is in the disengaged state.
A means 24 for giving 0 is provided.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 This invention relates to a power steering device for an automobile or the like.

[0002]

[Prior art]

 As a power steering device for reducing the steering force of a steering wheel of an automobile or the like, there is known a power steering device configured as shown in, for example, FIG. 4 (Japanese Patent Laid-Open No. 62-218273).

In this case, when the handle 5 is rotated, the rotation is transmitted to the column shaft 6 to move the rack shaft 3 via the pinion 7 at the tip of the shaft 6, while the torque sensor 7A detects the rotation of the handle 5. Then, the controller 8 drives the motor 9 in accordance with the detection values of the torque sensor 7A and the vehicle speed sensor 12, and power assists the movement of the rack shaft 3, that is, the steering of the tire 1 via the pinion 9A. . Reference numeral 10 denotes a speed reducer for increasing the output torque of the motor 9.

[0004]

[Problems to be solved by the device]

 However, in such a conventional device, there is a problem that vibration of the tire 1 due to the road surface condition is transmitted from the rack shaft 3 to the steering wheel 5 side in the vehicle compartment through the pinion 7, causing unpleasant vibration and noise. . Therefore, it is conceivable to interrupt the transmission of vibrations or the like from the tire 1 to the handlebar 5 side, but if the handlebar 5 side and the rack shaft 3 side are mechanically separated, the tire 1 can be manually operated when the controller 8 or the motor 9 fails. Since it becomes impossible to steer, it becomes a problem how to secure the fail-safe function.

The present invention aims to solve such problems.

[0006]

[Means for Solving the Problems]

 Therefore, this invention has a steering gear that transmits the rotation of the steering wheel, a linkage that steers the tire in conjunction with the steering gear, a motor that power-assists the movement of the linkage, and a means that detects the rotation of the steering wheel. The motor control means that drives the motor according to the rotation of the steering wheel, the electromagnetic clutch mechanism that connects and disconnects the rotation transmission from the steering wheel to the steering gear side, and this clutch mechanism operates the solenoid during normal operation of the motor and its control means. A clutch control means is provided for energizing and disconnecting, and for disconnecting and energizing the solenoid when an abnormality occurs. Further, means for applying a steering reaction force to the steering wheel when the clutch mechanism is in the disengaged state is provided.

[0007]

[Action]

 During normal operation (when the motor and its control means are normal), the clutch mechanism disconnects the rotation transmission path from the steering wheel to the steering gear, so tire vibrations, etc. from the linkage through the steering gear to the passenger compartment. It is not transmitted to the handle side of.

When an abnormality occurs in the motor and its control means, the clutch mechanism returns to the coupled state by demagnetization of solenoid, so that the fail-safe function, that is, the manual steering operation of the tire can be secured. The solenoid of the clutch mechanism is demagnetized even when the engine key is turned off when the vehicle is stopped, so that the rotation of the steering wheel can be transmitted to the linkage.

During normal operation, the steering wheel rotates with almost no resistance due to the disengaged state of the clutch mechanism, but if a means for applying a steering reaction force to the steering wheel is provided, an appropriate steering sensation can be provided.

[0010]

【Example】

 In FIG. 1, reference numeral 20 is a handle for receiving steering torque, and 21 is a column shaft. Gearboxes 22 and 23 are formed on the input side (instrument panel side) and the output side (engine room side) of the column shaft, respectively. In the input side gear box 22, a reaction force motor 24 that generates a steering reaction force of the steering wheel 20, a rack 26 and pinions 27 and 28 that transmit the rotational force of the motor to the column shaft 21 via the speed reducer 25, A potentiometer 29 (variable resistor) for detecting the steering angle of the handle 20 from the stroke (movement amount) of the rack 26 and a torque sensor 30 for detecting the rotational force (steering force) of the handle 20 are provided.

In the output side gear box 23, a rack shaft 32 that meshes with the pinion 31 at the tip of the column shaft 21, a power steering motor 35 with a speed reducer 34 that is connected to a pinion 33 that meshes with the rack shaft 32, and a rack shaft. A potentiometer 37 for detecting the steering angle of the tire 36 from the stroke of 32 and an electromagnetic clutch mechanism 38 for connecting and disconnecting the column shaft 21 are provided.

As shown in FIG. 2, the clutch mechanism 38 includes a holder 41 which is coupled to a flange surface of an input shaft 40 (which is coupled to the handle 20 side) and an outer periphery of an output shaft 42 (which is coupled to the pinion 31 side). An armature 45 fitted to the holder 43 with a spline 44, a return spring 46 for biasing the armature 45 toward the holder 41 side, and a solenoid coil 48 for generating an exciting force for attracting the armature 45 to the stator 47 side, and 48. The armature 45 is constituted by a tooth ring 49 and the like that connects and disconnects with the holder 41 along with the movement in the axial direction.

When the solenoid coil 48 inside the stator 47 is energized, the armature 45 is attracted toward the stator 47 side against the return spring 46 by the exciting force, and the tooth ring 49 is disengaged (the input shaft 40 and the On the other hand, when the power supply to the solenoid coil 48 is cut off, the armature 45 is pressed and urged toward the holder 41 by the return spring 46, and the tooth ring 49 is engaged (the input shaft 40 and the output shaft 42). Connect).

The controller 50 controls the operations of the power steering motor 35, the reaction force motor 24, and the clutch mechanism 38. When the motors 35 and 24 are operating without failure and the control system is functioning normally, the clutch mechanism 38 operates. The solenoid coil 48 is energized to interrupt the transmission of the handle rotation to the pinion 31 side. When the steering wheel 20 is turned in this state, the required output torque (power steering torque) of the motor 35 is obtained based on the detection signals from the potentiometer 29 and the torque sensor 30 and the vehicle speed sensor 51 which detects the traveling speed of the vehicle. The operating force) is obtained, and a current corresponding to the operating force is applied to the motor 35, and the drive of the motor 35, that is, the steering of the tire 36 is feedback-controlled based on the detection signals from the potentiometers 29 and 37. At the same time, the required output torque (steering reaction force of the steering wheel) of the motor 24 is obtained according to the detection signals from the potentiometer 29, the torque sensor 30, and the vehicle speed sensor, and the motor 24 is driven with a current that matches the required output torque.

When any abnormality occurs in the motors 35 and 24 and the control system, the control operation of the motors 35 and 24 is stopped, the energization of the clutch mechanism 38 is cut off, and the column shaft 21 is connected. It is like this. The controller 50 is equipped with a correction function for automatically steering, automatically avoiding obstacles such as the route of the vehicle, and automatically correcting the route when a crosswind is received. Various sensors 52 for detecting the external environment such as the condition and cross wind and the driving condition such as cornering and lane change are added. Reference numeral 53 indicates a power source of the controller 50.

With such a configuration, when the steering wheel 20 is rotated during normal operation, the power steering motor 35 is driven to move the rack shaft 32 in response to the rotation, so that the tire 36 can be steered with a light steering wheel operation. In this normal state, the clutch mechanism 38 disconnects the rotation transmission path from the handle 20 to the rack shaft 32 side by energizing the solenoid coil 48, so that vibration of the tire 36 causes the pinion 31 to move from the rack shaft 32. It will not be transmitted to the steering wheel 20 side inside the vehicle through the vehicle. Further, since the clutch mechanism 38 is maintained in the disengaged state even during the correction operation, even if the steering angle of the tire 36 is automatically corrected by the drive of the motor 35, the handle 20 does not tend to turn freely.

The steering wheel 20 rotates with almost no resistance when the clutch mechanism 38 is in the disengaged state, but since the steering wheel 20 is provided with the motor 24 and the like for applying a steering reaction force, a proper steering feeling can be provided. it can.

When an abnormality occurs in the motors 35, 24 and the control system thereof, the clutch mechanism 38 is connected in a coupled state by demagnetizing the solenoid 48, and the steering wheel rotation is directly transmitted to the rack shaft 32 side. The steering operation of the tire 36 can be secured. The solenoid 48 of the clutch mechanism 38 is demagnetized even when the engine key is turned off when the vehicle is stopped, so that the rotation of the handle 20 can be transmitted to the rack shaft 32.

FIG. 3 shows another embodiment. In this case, in order to minimize the input side gear box (instrument panel part) around the steering wheel in terms of space, a reaction force motor that applies a steering reaction force of the steering wheel 20. 24 and the torque sensor 30 are also housed in the output side gear box (engine room side). Further, instead of the potentiometers 29 and 37, rudder angle sensors 29A and 37A that detect the rotation angle of the column shaft 21 on the input shaft side and the output shaft side of the clutch mechanism 38 are used. It becomes possible to make it short and compact. The same parts as those in FIG. 1 are designated by the same reference numerals, and the duplicate description will be omitted.

[0020]

[Effect of device]

 In short, according to the present invention, the steering gear that transmits the rotation of the steering wheel, the linkage that steers the tire in conjunction with the steering gear, the motor that power assists the movement of the linkage, and the rotation of the steering wheel are detected. Means, a motor control means for driving the motor in response to the rotation of the handle, an electromagnetic clutch mechanism for connecting and disconnecting the rotation transmission from the steering wheel to the steering gear side, and this clutch mechanism for the motor and its control means. Since the solenoid is energized and disconnected during normal operation, and the clutch control means for disconnecting and energizing the solenoid in the event of an abnormality is provided, a fail-safe mechanism, that is, manual operation, is provided when the motor and its control means fail. While ensuring proper steering of the tires, vibration of the tires etc. from the linkage during normal operation Effect that can prevent the transmitted into the cabin of the handle side through the Tearingugiya.

Further, during normal operation, the steering wheel turns with almost no resistance due to the disengaged state of the clutch mechanism, but if a means for applying a steering reaction force to the steering wheel is provided, an appropriate steering feeling can be provided.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an embodiment of the present invention.

FIG. 2 is a sectional view of the clutch mechanism of the same.

FIG. 3 is a configuration diagram showing another embodiment.

FIG. 4 is a configuration diagram illustrating a conventional technique.

[Explanation of symbols]

 20 Handle 21 Column Shaft 24 Reaction Motor 29,37 Potentiometer 29A, 37A Steering Angle Sensor 30 Torque Sensor 31, 33 Pinion 32 Rack Shaft 35 Power Steering Motor 38 Clutch Mechanism 48 Solenoid 50 Controller 51 Vehicle Speed Sensor

Claims (2)

[Scope of utility model registration request] 1. A steering gear to which rotation of a steering wheel is transmitted, a linkage for steering a tire in association with the steering gear, a motor for power assisting movement of the linkage, a means for detecting rotation of the steering wheel, and a steering wheel. Motor control means for driving the motor according to the rotation of
An electromagnetic clutch mechanism that interrupts the transmission of rotation from the steering wheel to the steering gear side, and this clutch mechanism energizes and disconnects the solenoid during normal operation of the motor and its control means, and energizes the solenoid when an abnormality occurs. A power steering apparatus comprising: a clutch control means for disconnecting and connecting the clutch. 2. The power steering apparatus according to claim 1, further comprising means for applying a steering reaction force to the steering wheel when the clutch mechanism is in a disengaged state.