JP2007168674A - Power steering system and control method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power steering system capable of automatically performing steering control if it is determined that a driver is drowsy even in case of using a hydraulic actuator. <P>SOLUTION: This power steering system includes a steering shaft connected to a steering wheel, a hydraulic power cylinder connected to the steering shaft and having a pair of hydraulic pressure chambers, a pump for feeding the power cylinder with hydraulic pressure, a steering shaft drive portion for providing the steering shaft with torque with the hydraulic pressure from the pump, an environmental information detector for detecting information on a vehicle, a driver and roads, and a hydraulic pressure control portion for controlling the hydraulic pressure provided to the steering shaft drive portion based on an output signal from the environmental information detector. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a power steering device that assists a driver's steering force with hydraulic pressure, and more particularly to an integral type power steering device used for a large vehicle.

Conventionally, in accordance with the vehicle driving support device disclosed in Patent Document 1, a white line recognition camera is used to appropriately drive a vehicle without deviating from the driving lane when the driver is falling asleep or driving aside. And a camera for recognizing the line of sight and blinking, and safety is ensured by automatically performing steering control when the vehicle deviates from the white line or the driver is determined to be dozing.
JP 11-339199 A

  However, in the above prior art, since automatic steering control is performed by an electric signal, automatic steering control can be easily applied to a type of power steering device using an electric motor as an actuator. In this case, since it is difficult to assist the steering with the electric motor, a hydraulic power steering apparatus that does not use the electric motor as an actuator is generally used. Therefore, it is difficult to apply the automatic steering control to the hydraulic actuator of the hydraulic power steering apparatus.

  The present invention has been made paying attention to the above problems, and the purpose thereof is to perform steering control automatically when the driver is determined to be dozing even when a hydraulic actuator is used. An object of the present invention is to provide a power steering device that can perform the above-described operation.

  To achieve the above object, according to the present invention, a steering shaft connected to a steering wheel, a hydraulic power cylinder connected to the steering shaft and having a pair of hydraulic chambers, and supplying hydraulic pressure to the hydraulic power cylinder A pump, a steering shaft drive that applies torque to the steering shaft by hydraulic pressure from the pump, environmental information detection means for detecting vehicle, driver or road information, and output signals of the environmental information detection means And a hydraulic pressure control unit for controlling the hydraulic pressure supplied to the steering shaft driving unit.

  Therefore, even when a hydraulic actuator is used, it is possible to provide a power steering device that can automatically perform steering control when the driver is determined to be dozing.

  Hereinafter, the best mode for realizing the power steering apparatus of the present invention will be described based on an embodiment shown in the drawings.

[System configuration of power steering system]
Example 1 will be described with reference to FIGS. FIG. 1 is a system configuration diagram of the power steering apparatus 1 of the present application.

  The power steering apparatus 1 includes a steering shaft 2 connected to a steering wheel SW, a rotary valve 600 that switches an assist direction, a piston 70 that is provided in a hydraulic power cylinder 10 and generates assist force by hydraulic pressure, and meshes with the piston 70. And a sector shaft 30 (transmission mechanism) that rotates by the reciprocating motion of the piston 70 to steer the steered wheels.

  The steering shaft 2 includes an input shaft 40 and an output shaft 60, and a torsion bar 50 (see FIG. 2) connecting the input / output shafts 40 and 60. Furthermore, the power steering device 1 includes left and right rotational torque generating input shaft driving units 100 and 200 (steering shaft driving units) that apply a reaction force to the input shaft 40 by hydraulic pressure, and the input shaft driving units 100 and 200. A hydraulic pressure control unit 300 (hydraulic pressure control means) that controls the hydraulic pressure of the hydraulic oil supplied to the engine.

  The left and right rotational direction torque generating input shaft driving units 100 and 200 are actuators that apply left and right torques to the input shaft 40, respectively. It functions as a reaction force actuator during normal steering, and when automatic steering control is required, such as during a driver's drowsy driving or side-view driving, the input shaft 40 is rotated to drive the rotary valve 600 to steer in the torque application direction. It functions as a steering actuator that performs assist.

  When the steering wheel SW is steered, the hydraulic oil discharged from the pump P enters one of the right steering cylinder chambers 21 and 22 (a pair of hydraulic chambers) separated by the rotary valve 600. Supplied. As a result, the piston 70 is driven, and the sector shaft 30 is rotated and steered. Excess hydraulic fluid is discharged to the reservoir 5.

  The hydraulic pressure control unit 300 includes a control unit 301 and control valves 310 and 320 for generating torque in the left and right rotation directions. The control unit 301 is connected to the battery E, and drives the control valves 310 and 320 for generating counterclockwise and rightward rotation direction torque based on a signal from the environment information detection unit 400 (environment information detection means) that detects the vehicle environment. The control valves 310 and 320 are connected to the rotary valve 600 through oil passages 6 and 7, respectively, and are supplied with the discharge pressure of the pump P.

  The environment information detection unit 400 includes a vehicle speed sensor 401, a white line recognition camera 403 on the road, and a driver's line-of-sight recognition camera 402. Based on the detected vehicle speed, the positional relationship between the white line and the vehicle, and the driver's line of sight, the control unit 301 drives the control valves 310 and 320 for generating counterclockwise and rightward rotational torque.

  As a result, the left and right rotational direction torque generating input shaft driving units 100 and 200 are driven during a drowsy operation or a side-view operation, and a reaction force torque in the left-right direction is applied to the input shaft 40. A warning is issued to the driver by vibrating the steering wheel SW connected to the input shaft 40.

  Control valves 310 and 320 for generating torque in the left and right rotation directions are connected to the rotary valve 600 to receive hydraulic oil. When the input shaft 40 rotates relative to the output shaft 60 in the right direction, the hydraulic oil is supplied to the left rotation direction torque generation control valve 310, and when it rotates relative to the left direction, it is supplied to the right rotation direction torque generation control valve 320. The Excess hydraulic fluid is discharged to the reservoir 5.

  The left and right rotation direction torque generation control valves 310 and 320 include left and right rotation direction torque generation solenoids SOL1 and SOL2, and left and right rotation direction torque generation spools 311 and 321, respectively. The spools 311 and 321 are driven by driving the solenoids SOL1 and SOL2 based on a command from the control unit 301, and the hydraulic pressure supplied to the left and right rotational direction torque generating input shaft driving units 100 and 200 To control.

  The left and right rotational direction torque generating input shaft driving units 100 and 200 are provided on the input shaft 40, and apply reaction force to the input shaft 40 by the hydraulic pressure from the control valves 310 and 320. The left rotation direction torque generating input shaft drive unit 100 applies a left rotation direction torque to the input shaft 40, and the right rotation direction torque generation input shaft drive unit 200 applies a right rotation direction torque.

[Axial sectional view]
FIG. 2 is an axial sectional view of the power steering apparatus. For the sake of explanation, the axial direction of the input / output shafts 40 and 60 is defined as the y-axis, and the input shaft 40 side is positive. Also, polar coordinates are defined around the y axis, and the radial direction is the r axis (the rotation direction is counterclockwise positive, see FIG. 3).

  The power steering apparatus 1 houses a first housing 11 that houses a rotary valve 600, a second housing 12 that houses a piston 70, and a sector shaft 30. The sector shaft 30 is provided in the sector shaft storage portion 13 in the second housing.

  The housings 11 and 12 are both substantially cup-shaped members and are connected to each other in the axial direction opening. An input shaft 40 connected to the steering wheel is inserted into the bottom of the first housing 11 in the axial direction, and the piston 70 in the second housing 12 is slid in the y-axis direction by hydraulic pressure according to the rotation of the input shaft 0. .

  The second housing 12 and the sector shaft 30 are provided at right angles to each other in the axial direction. The teeth provided on the piston 70 in the second housing 12 and the teeth provided on the sector shaft 30 mesh with each other, and the piston slides. The sector shaft 30 is rotated to perform steering assist.

  A piston 70 is accommodated in the second housing 12 so as to be movable in the axial direction. By this piston 70, the second housing 12 has a right steering cylinder chamber 21 on the input shaft side and a left steering cylinder chamber on the cup-shaped bottom side. 22 is separated in a liquid-tight manner.

  The input shaft 40 is connected to the output shaft 60 by a torsion bar 50. The output shaft 60 has a hollow cylindrical shape, and the input shaft 40 is accommodated on the y axis positive direction side of the hollow portion, and the torsion bar 50 is accommodated on the y axis negative direction side. By providing the torsion bar 50 between the input / output shafts 40, 60, the torque applied to the input shaft 40 from each input shaft drive unit 100, 200 is absorbed by the elastic force of the torsion bar 50, and the influence on the steered wheels is affected. Make it smaller.

  Further, an input shaft serration groove 41 (inclined surface) and an output shaft serration groove 61 (see FIG. 3) are formed in the overlapping portion of the input shaft 40 and the output shaft 60 on the negative y-axis side of the rotary valve 600. In addition, left and right rotational direction torque generating input shaft driving units 100 and 200 are provided. The convex top 44 (regulator) of the input shaft serration groove 41 is locked to the concave portion of the output shaft serration groove 61 (see FIG. 3), so that the input / output shafts 40 and 60 have a relative allowable rotational amount. The rotation is restricted and the torsion bar 50 is prevented from being twisted more than necessary.

  The left and right rotational direction torque generating input shaft drive units 100 and 200 are provided in parallel on the y-axis negative direction side of the rotary valve 600. The left and right rotational direction torque generating input shaft driving units 100 and 200 have r-axis radial holes 110 and 210 on the output shaft 60, respectively, and left and right rotational direction torque generating pistons 120 and 220 (pistons, respectively). (Member).

  A left rotation direction torque generation chamber D1 (first hydraulic pressure introduction portion) is formed on the r axis direction outer diameter side of the left rotation direction torque generation piston 120, and a right rotation direction torque generation piston 220 on the outer diameter side. A rotation direction torque generation chamber D2 (second hydraulic pressure introduction portion) is formed. The left rotation direction torque generation chamber D1 communicates with the right steering cylinder chamber 21 through the oil passages 31 and 33 via the left rotation direction torque generation control valve 310, and the right rotation direction torque generation chamber D2 has the right rotation direction torque. The left steering cylinder chamber 22 communicates with the oil passages 32 and 34 via the generation control valve 320.

  Thus, the hydraulic pressures in the right and left steering cylinder chambers 21 and 22 are controlled by the control valves 310 and 320 and supplied to the left and right rotational direction torque generating input shaft driving units 100 and 200, respectively.

  The output shaft 60 is inserted into the piston 70 in the axial direction, and is fitted to the piston 70 by the ball screw mechanism 61. A piston tooth portion 71 (conversion mechanism) carved in the circumferential direction is provided on the outer periphery of the piston 70, and the piston 70 meshes with the sector shaft 30 in the piston tooth portion 71.

  The second housing 12 is provided so that its axis is orthogonal to the sector shaft 30, and a sector shaft storage portion 13 that stores a part of the sector shaft 30 is provided in a part of the second housing 12 in the radial direction. The sector shaft storage portion 13 is supplied with hydraulic oil and communicates with the right steering cylinder chamber 21 to lubricate the sector shaft 30 and the piston tooth portion 71 in mesh.

  The right steering cylinder chamber 21 in the second housing 12 communicates with the rotary valve 600 through the right steering cylinder chamber communication passage 15 provided in the first housing 11, and the left steering cylinder chamber 22 includes the second housing 12 and the second housing 12. The left steering cylinder chamber communication path 16 provided across one housing 11 communicates with the rotary valve 600.

  The rotary valve 600 functions as a valve mechanism for introducing or discharging oil from the IN port and the OUT port to the right and left steering cylinder chambers 21 and 22 according to the rotation of the input shaft 40. When the input shaft 40 rotates to the right relative to the output shaft 60, the pump P and the right steering cylinder chamber 21 are communicated. When relatively rotated to the left, the pump P communicates with the left steering cylinder chamber 22.

[Details of steering shaft drive]
FIG. 3 is a radial sectional view of the input shaft driving unit 200 for generating torque in the right rotational direction. The left rotational direction torque generating input shaft driving unit 100 provided on the y-axis positive direction side is indicated by a broken line.

  As described above, the left and right rotational direction torque generating input shaft driving units 100 and 200 are respectively provided with four r-axis radial holes 110 and 210 provided at equal intervals with respect to the output shaft 60. It is formed by retracting the right rotational direction torque generating pistons 120 and 220. Left-rotation direction and right-rotation direction torque generation chambers D1 and D2 are formed on the outer diameter side of the pistons 120 and 220 in the r-axis direction.

  Further, substantially spherical contact portions 121 and 221 are provided at the inner ends of the left and right rotational direction torque generating pistons 120 and 220 on the inner side in the r-axis direction. As the pistons 120 and 220 move toward the inner diameter side in the r-axis direction due to the hydraulic pressures of the torque generation chambers D1 and D2, the contact portions 121 and 221 press the serration grooves 41 on the input shaft 40 side.

  Here, the left and right rotational direction torque generating input shaft driving units 100 and 200 are provided with their rotational direction positions shifted from each other. That is, the AA line and the A′-A ′ line, which are the axes of the radial hole 110 of the left rotational direction torque generating input shaft drive unit 100, and the radial direction hole 211 of the right rotational direction torque generating input shaft drive unit. The BB line and the B′-B ′ line, which are the axis lines, are offset from each other by an angle θ.

  Due to this offset, the AA line and A′-A ′ line of each radial hole 110, 210 are opposite to the CC line and C′-C ′ line, which are the axis lines of the recesses of the input shaft serration groove 41. It is provided with a shift of θ / 2 in the clockwise direction. Similarly, the BB line and the B′-B ′ line are provided with a shift of the angle θ / 2 in the clockwise direction with respect to the CC line and the C′-C ′ line.

  Accordingly, the right rotational direction torque generating contact portion 221 is formed on the left rotational direction torque generating convex inclined surface 42 on the BB line and B′-B ′ line side with respect to the CC line and C′-C ′ line. The input shaft 40 is pressed at the (second inclined surface), and the counterclockwise torque generation contact portion 121 is on the line AA, A′-A ′ with respect to the line CC, C′-C ′. The input shaft 40 is pressed on the convex portion inclined surface 43 (first inclined surface) for generating torque in the left rotational direction.

  Since the input shaft 40 can rotate with a predetermined allowable amount, the torque in the right rotational direction acts on the input shaft 40 when the right rotational direction torque generating convex inclined surface 42 is pressed toward the inner diameter side of the r axis. The input shaft 40 rotates. Thus, the left rotation direction torque generating contact portion 121 presses the input shaft 40 in the left rotation direction, and the right rotation direction torque generation contact portion 221 presses the input shaft 40 in the right rotation direction.

  By making the contact portions 121 and 221 substantially spherical, the contact between the left and right rotational direction torque generating pistons 120 and 220 and the serration groove 41 of the input shaft 40 is made smooth, and the left and right rotational direction torque generating pistons 120 and 220 are smoothed. The axial movement of 220 is smoothly converted into the rotational movement of the input shaft 40.

[Supplying hydraulic oil to the steering shaft drive]
FIG. 4 is a cross-sectional view in the axial direction of the power steering apparatus 1 at the time of rightward steering assist. When the steering wheel SW is steered in the right direction, pump pressure is introduced into the right steering cylinder chamber 21 by the rotary valve 600, and a differential pressure is generated between the right steering cylinder chamber 21 and the left steering cylinder chamber 21. As a result, the piston 70 moves in the negative y-axis direction, the sector shaft 30 rotates counterclockwise, and rightward steering assist is performed.

  At that time, the hydraulic oil in the right steering cylinder chamber 21 is introduced into the left rotation direction torque generation control valve 310 through the oil passage 31 and hydraulically controlled, and is introduced into the left rotation direction torque generation chamber D1 through the oil passage 33. Is done. As a result, the left rotation direction torque generating piston 120 is driven, and the left rotation direction torque generation input shaft driving unit 100 presses the input shaft 40 in the left rotation direction, thereby applying reaction force torque.

  Similarly, during left-hand steering assist, the hydraulic oil in the left-hand steering cylinder chamber 22 is also introduced into the right-rotation direction torque generation chamber D2 via the oil passage 16 and the oil passages 32 and 34, and is input to the right-rotation direction torque generation input shaft. The drive unit presses the input shaft 40 in the clockwise direction and applies reaction torque.

[Applying reaction force to the input shaft]
FIG. 5 is a radial sectional view of the left rotational direction torque generating input shaft driving unit 100, and FIG. 6 is a radial direction sectional view of the right rotational direction torque generating input shaft driving unit 200. A case where torque is applied to each input shaft 40 is shown.

(Normal steering)
As described above, when the hydraulic pressure in the right steering cylinder chamber 21 is high during normal steering, the input shaft 40 is applied with torque in the left rotation direction by the left rotation direction torque generation input shaft drive unit 100, and left steering is performed. When the hydraulic pressure in the cylinder chamber 22 is high, torque in the clockwise direction is applied. In accordance with the vehicle speed detected by the vehicle speed sensor 401, the control valves 310 and 320 for generating torque in the left and right rotation directions are driven, and torque corresponding to the environmental information is applied to the input shaft 40.

(When snoozing is detected)
When the driver's drowsiness is detected by the line-of-sight recognition camera 402, the left and right rotational direction torque generating input shaft driving units 100 and 320 are alternately driven by driving the left and right rotational direction torque generating control valves 310 and 320. The hydraulic pressures in the 200 torque generation chambers D1 and D2 are alternately raised and lowered.

  Accordingly, the left and right rotational direction torque generating pistons 120 and 220 alternately press the input shaft 40, and the input shaft 40 repeats left-right bi-directional rotation and vibrates in the torsional direction. As a result, the steering wheel SW connected to the input shaft 40 vibrates in the left-right twist direction, and issues a warning to the driver.

(When lane departure is detected)
When the lane departure state is detected by the white line recognition camera 403, the control valves 310 and 320 for generating torque in the left and right rotation directions are driven to rotate the input shaft 40, and the allowable rotation range of the serration grooves 41 and 61 The input / output shafts 40 and 60 are relatively rotated. As a result, the opening degree of the rotary valve 600 is changed, steering assist is performed, and the lane is returned.

  For example, when the vehicle deviates to the left side, the right rotation direction torque generating control valve 320 is driven to apply a reaction force in the right rotation direction to the input shaft 40, and the rotary valve 600 is rotated to the right side. . As a result, the hydraulic pressure in the right steering cylinder chamber 21 increases, and an assist force in the right steering direction is generated to turn the vehicle in the right direction to avoid lane departure. When the vehicle deviates to the left side, the vehicle is turned counterclockwise by driving the left rotation direction torque generation control valve 310.

[Normal reaction force generation control process during steering]
FIG. 7 is a flowchart showing the flow of the normal steering reaction force generation control process. Hereinafter, each step will be described.

  In step S100, environmental information (vehicle speed, driver's line of sight, and distance between the vehicle and the white line) is detected, and the process proceeds to step S200 (first step).

  In step S200, the control valves 310 and 320 for generating torque in the left and right rotation directions are driven according to the detected environment information, and control is performed so as to apply torque according to the environment information to the input shaft 40, and the process proceeds to step S300. Transition (second step).

  In step S300, it is determined whether the steering is right or left. If it is left, the process proceeds to step S400, and if it is right, the process proceeds to step S600.

  In step S400, the hydraulic pressure in the left steering cylinder chamber 22 is supplied to the right rotational direction torque generation input shaft drive unit 200 via the right rotational direction torque generation control valve 320, and the process proceeds to step S500 (third step). .

  In step S500, a reaction torque in the right rotation direction is applied to the left steering of the input shaft 40, and the control is terminated (fourth step).

  In step S600, the hydraulic pressure in the right steering cylinder chamber 21 is supplied to the left rotation direction torque generation input shaft drive unit 100 via the left rotation direction torque generation control valve 310, and the process proceeds to step S700 (third step). .

  In step S700, a reaction torque in the left rotation direction is applied to the right steering of the input shaft 40, and the control is terminated (fourth step).

[Dozing state warning control process]
FIG. 8 is a flowchart showing the flow of the dozing state warning control process executed in step S200.

  In step S211, it is determined whether or not the patient is in a doze state based on the signal from the line-of-sight recognition camera 402. If YES, the process proceeds to step S212, and if NO, the control is terminated (first step).

  In step S212, the left rotation direction torque generation control valve 310 is driven to apply a left direction torque to the input shaft 40, and the process proceeds to step S213.

  In step S213, driving of the left rotation direction torque generating control valve 310 is stopped, and the process proceeds to step S214.

  In step S214, the right rotation direction torque generating control valve 320 is driven to apply a right direction torque to the input shaft 40, and the process proceeds to step S215.

  In step S215, the drive of the right rotation direction torque generation control valve 320 is stopped, and the process returns to step S211.

[Lane departure avoidance control processing]
FIG. 9 is a flowchart showing the flow of the left lane departure avoidance control process executed in step S200.

  In step S221, it is determined whether the vehicle is in a lane departure state. If YES, the process proceeds to step S222, and if NO, the control is terminated (first step).

  In step S222, it is determined whether the departure direction is left or right. If the direction is left, the process proceeds to step S223. If the direction is right, the process proceeds to step S226.

  In step S223, the right rotation direction torque generation control valve 320 is driven to apply torque in the right steering direction to the input shaft 40, and the process proceeds to step S224.

  In step S224, the rotary valve 600 rotates to the right, the hydraulic pressure P1 in the right steering cylinder chamber 21 rises, and the process proceeds to step S225.

  In step S225, an assist force in the right direction is generated, the vehicle is turned clockwise, and the control is terminated.

  In step S226, the left rotation direction torque generation control valve 310 is driven to apply torque in the left steering direction to the input shaft 40, and the process proceeds to step S224.

  In step S227, the rotary valve 600 rotates counterclockwise, the hydraulic pressure P2 in the left steering cylinder chamber 22 increases, and the process proceeds to step S228.

  In step S228, an assist force in the left direction is generated, the vehicle is turned counterclockwise, and the control ends.

[Effect of the embodiment of the present application]
(1) In the embodiment of the present application, an input shaft 40 connected to the steering wheel SW, a hydraulic power cylinder 10 connected to the input shaft 40 and having a pair of right steering and left steering cylinder chambers 21 and 22; A pump P for supplying hydraulic pressure to the power cylinder 10; left and right rotational direction torque generating input shaft driving units 100 and 200 for applying torque to the input shaft 40 by the hydraulic pressure from the pump P; An environmental information detection unit 400 that detects road information, and a hydraulic pressure control that controls the hydraulic pressure supplied to the left and right rotational direction torque generation input shaft driving units 100 and 200 based on the output signal of the environmental information detection unit 400 Part 300.

  This makes it possible to drive the left and right rotational direction torque generating input shaft driving units 100 and 200 by the hydraulic pressure of the pump P that supplies the hydraulic pressure to the hydraulic power cylinder 10, and a drive source such as an electric motor is separately provided. A reaction force can be applied to the input shaft 40 without providing it.

  (2) The steering shaft 2 includes an input shaft 40 connected to the steering wheel SW side, an output shaft 60 connected to the hydraulic power cylinder 10 side, and a torsion bar 50 connecting the input shaft 40 and the output shaft 60. The left and right rotational direction torque generating input shaft driving units 100 and 200 are configured to apply torque to the input shaft 40 side.

  As a result, torque can be applied to the input shaft 40 closer to the driver than the torsion bar 50, which is an elastic member, and the generation of torque can be clearly transmitted to the driver. Further, since the output shaft 60 connected to the hydraulic power cylinder 10 side is connected via the torsion bar 50, this torque is absorbed by the elastic force of the torsion bar 50, and the influence on the steered wheels is reduced. Can do.

  (3) The environment information detection unit 400 detects the driver's doze or side-view driving. As a result, when a driver's dozing or side-by-side driving is detected, the left and right rotational direction torque generating input shaft driving units 100 and 200 apply torque to the input shaft 40 and transmit this torque to the driver. Thus, it is possible to issue a warning about falling asleep or forgetting to the driver.

  (4) Based on the twist amount and twist direction of the input shaft 40 and the output shaft 60 connected to the torsion bar 50, the pump P moves from the pair of right and left steering cylinder chambers 21 and 22 to the hydraulic power cylinder 10. A rotary valve 600 that selects the supply amount and supply direction of the supplied hydraulic pressure is further provided.

  When the input shaft drive units 100 and 200 for generating torque in the left and right rotational directions apply torque to the input shaft 40 side, a relative rotation occurs between the input and output shafts 40 and 60, and the rotary valve 600 rotates and the pump The discharge pressure of P is selectively supplied to the right steering and left steering cylinder chambers 21 and 22. As a result, the hydraulic power cylinder 10 can be driven and controlled by the pump discharge pressure.

  (5) The environmental information detection unit 400 detects the relative position between the traveling road and the vehicle, and the hydraulic pressure control unit 300 is based on the output signal of the environmental information detection unit 400 so that the vehicle does not deviate from the traveling road. The drive control of the input shaft driving units 100 and 200 for generating the right rotational direction torque is performed.

  The left and right rotational direction torque generating input shaft driving units 100 and 200 are driven and controlled so that the vehicle does not deviate from the traveling road, and the hydraulic power cylinder 10 is driven and controlled by the pump discharge pressure. Lane departure prevention control can be performed without providing an actuator separately for driving the vehicle.

  (6) The left and right rotational direction torque generating input shaft driving units 100 and 200 include the left rotational direction torque generating convex inclined surfaces 42 and 43 provided on the outer periphery of the input shaft 40 and the left rotational direction torque generation. The piston 70 is provided on the outer peripheral side of the convex slopes 42 and 43 for use, and rotates the input shaft 40 by being pressed against the convex slopes 42 and 43 for torque generation in the counterclockwise direction. The torque generation chambers D1 and D2 into which the hydraulic pressure from the hydraulic pressure control unit 300 is introduced are configured.

  Thereby, the torque provided to the input shaft 40 can be generated using the discharge pressure from the pump P.

  (7) The left and right rotational direction torque generating pistons 120 and 220 have contact portions 121 and 221 formed in a curved surface at the contact portions with the left rotational direction torque generating convex inclined surfaces 42 and 43, respectively. It was.

  Thereby, the contact between the left and right rotational direction torque generating pistons 120 and 220 and the serration groove 41 of the input shaft 40 is smoothed, and the axial movement of the left and right rotational direction torque generating pistons 120 and 220 is smoothly performed on the input shaft 40. Can be converted into a rotational motion.

  (8) The left-rotation direction torque generating convex inclined surfaces 42 and 43 further include a top 44 that restricts rotation of the input shaft 40 by a predetermined angle or more. Thereby, the relative rotation amount of the input shaft 40 and the output shaft 60 can be suppressed within a predetermined rotation amount.

  (9) The left and right rotational direction torque generating input shaft driving units 100 and 200 include the left rotational direction torque generating convex inclined surface 42 provided on the outer periphery of the input shaft 40 and the left rotational direction torque generating convex portion. Provided on the outer peripheral side of the inclined surface 42 and provided on the outer periphery of the input shaft 40 and a left-rotation direction torque generating piston 120 that rotates the input shaft 40 in the forward direction by pressing the first convex inclined surface. The right rotational direction torque generating convex portion inclined surface 43 and the right rotational direction torque generating convex portion inclined surface 43 provided on the outer peripheral side, and pressing the right rotational direction torque generating convex portion inclined surface 43. Thus, it is configured to include a right-rotation direction torque generating piston 220 that rotationally drives the input shaft 40 in the reverse direction.

  Thereby, the input shaft 40 can be rotated forward and backward in both the left and right directions.

  (10) The environment information detection unit 400 detects the driver's doze or side-view driving, and the hydraulic pressure control unit 300 detects the driver's doze or side-view driving when the environment information detection unit 400 detects the driver's doze or side-view driving. The hydraulic pressure is alternately supplied to the generation chamber D1 and the right rotational direction torque generation chamber D2.

  By driving the input shaft 40 to rotate alternately in the forward and reverse directions, it is possible to give a warning to the driver about a drowsy driving or a side driving.

  (11) The environment information detection unit 400 detects the relative position between the travel path and the vehicle, and the hydraulic pressure control unit 300 determines the left position based on the relative position between the travel path and the vehicle detected by the environment information detection unit 400. The hydraulic pressure is selectively supplied to the rotation direction torque generation chamber D1 or the right rotation direction torque generation chamber D2.

  Thereby, it becomes possible to rotationally drive the input shaft 40 contrary to the traveling road departure direction, and deviation from the traveling road can be prevented.

  (12) The hydraulic pressure control unit 300 is driven by the left and right rotation direction torque generation solenoids SOL1 and SOL2 and the left and right rotation direction torque generation solenoids SOL1 and SOL2 that are driven based on the output signal from the environment information detection unit 400. The left and right rotation direction torque generation control valves 310 and 320 are connected and control the hydraulic pressure from the pump P to the left and right rotation direction torque generation input shaft driving units 100 and 200.

  Based on the signal from the environment information detection unit 400, the hydraulic pressure can be controlled.

  (13) The left and right rotational direction torque generation solenoids SOL1 and SOL2 and the left and right rotational direction torque generation control valves 310 and 320 are provided coaxially and parallel to the input shaft 40. Thereby, the enlargement of the radial direction dimension of an apparatus can be avoided.

  (14) A housing, an input shaft 40 connected to the steering wheel SW, a piston that is housed in the housing, and that separates the inside of the housing into right and left steering cylinder chambers 21 and 22, and an input shaft 40 A sector shaft 30 that converts the rotation of the piston into the axial movement of the piston, a rotary valve 600 that selectively supplies hydraulic oil supplied from the pump P to the right and left steering cylinder chambers 21 and 22, and a piston A transmission mechanism for transmitting the axial movement of the motor to the input shaft 40, a pump P for supplying hydraulic pressure to the right or left steering cylinder chambers 21, 22, and torque to the input shaft 40 by the hydraulic pressure from the pump P Left and right rotational direction torque generating input shaft driving units 100 and 200 to be applied, an environment information detecting unit 400 for detecting vehicle, driver or road information, and environment information Based on the output signal of the output portion 400, it was decided to have a hydraulic pressure controller 300 for controlling the hydraulic pressure supplied left and right rotation direction torque generating input shaft driving unit 100 and 200.

  Thereby, even in the integral type power steering apparatus used for a large vehicle, the same effect as that of the first aspect can be obtained.

  (15) In the power steering device of the present application, step S100 (first step) for detecting vehicle, driver or road information and the left and right rotational direction torque generation control valves 310 and 320 based on the detection result of step S100. Step S200 (second step) for controlling the hydraulic pressure from the external hydraulic pressure source, and the left and right rotational direction torque generating input shaft driving unit 100 provided on the input shaft 40 with the hydraulic pressure controlled in Step S200. Steps S400 and S600 (third step) to be supplied to, 200, and left and right rotational direction torque generating input shaft driving units 100 and 200 to which hydraulic pressure has been supplied in S400 and S600 drive the input shaft 40. S500 and S700 (fourth step).

  Thereby, the effect of Claim 1 is realizable concretely.

  (16) When the driver's dozing or side-view driving is detected in step S100 (first step), the left and right rotational direction torque generation control valves 310, so as to vibrate the input shaft 40 in step S200 (second step), 320 is controlled to be driven. Thereby, the effect of Claim 10 is realizable concretely.

  (17) When a deviation of the vehicle from the lane is detected in step S100 (first step), the torque in the left and right rotational directions is such that the input shaft 40 is steered toward the center of the lane in step S200 (second step). The generation control valves 310 and 320 are driven and controlled. Thereby, the effect of Claim 5 is realizable concretely.

  (18) In accordance with the vehicle speed detected in step S100 (first step), the left and right rotational direction torque generation control valves 310 and 320 are driven and controlled in step S200 (second step) and applied to the input shaft 40. The steering load is variably controlled. Thereby, it is possible to perform the optimum steering assist in consideration of the road surface resistance that changes according to the vehicle speed.

  (19) As the vehicle speed detected in step S100 (first step) increases, the left and right rotational direction torque generation control valve increases so that the steering load applied to the input shaft 40 in step S200 (second step) increases. 310 and 320 are driven and controlled. As a result, it is possible to achieve both the straight running stability at high speed and the reduction of the steering load at low speed.

[Other embodiments]
As described above, the best mode for carrying out the present invention has been described based on the first embodiment. However, the specific configuration of the present invention is not limited to each embodiment and does not depart from the gist of the present invention. Such design changes are included in the present invention.

1 is a system configuration diagram of a power steering apparatus 1 of the present application. It is an axial sectional view of a power steering device. It is radial direction sectional drawing of a 1st steering shaft drive part. It is an axial sectional view of a power steering device at the time of right direction steering assist. It is radial direction sectional drawing of the input shaft drive part for the left rotation direction torque production | generation. It is radial direction sectional drawing of the input shaft drive part for right rotation direction torque production | generation. It is a flowchart which shows the flow of the reaction force generation control process at the time of normal steering. It is a flowchart which shows the flow of a warning control process at the time of a dozing state. It is a flowchart which shows the flow of the lane departure avoidance control process to the left direction.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Power steering apparatus 2 Steering shaft 5 Reservoir 6, 7 Oil path 10 Hydraulic power cylinders 11 and 12 1st, 2nd housing 13 Sector shaft storage part 15 Right steering cylinder chamber communication path 16 Left steering cylinder chamber communication path 21, 22 Cylinder chamber 30 for right steering and left steering 30 Sector shafts 31 to 34 Oil passage 40 Input shafts 41 and 61 Serration grooves 42 and 43 Left and right rotational direction torque generating convex inclined surface 44 Top 50 Torsion bar 60 Output shaft 70 Piston 100 , 200 Left and right rotational direction torque generating input shaft drive units 110 and 210 Radial holes 120 and 220 Pistons 121 and 221 Abutting unit 300 Hydraulic control unit 301 Control units 310 and 320 Left and right rotational direction torque generating control valve 311, 321 Spool 400 Environmental information detection unit 401 Car Sensor 402 line-of-sight recognition camera 403 white line recognition camera 600 rotary valve D1, D2 left, right rotation direction torque generating chamber E battery P pump SOL1, SOL2 solenoid

Claims (19)

A steering shaft connected to the steering wheel;
A hydraulic power cylinder connected to the steering shaft and having a pair of hydraulic chambers;
A pump for supplying hydraulic pressure to the hydraulic power cylinder;
A steering shaft drive unit that applies torque to the steering shaft by hydraulic pressure from the pump;
Environmental information detection means for detecting vehicle, driver or road information;
A power steering apparatus comprising: a hydraulic pressure control unit that controls a hydraulic pressure supplied to the steering shaft driving unit based on an output signal of the environmental information detection means. The power steering apparatus according to claim 1, wherein
The steering shaft is composed of an input shaft connected to the steering wheel side, an output shaft connected to the hydraulic power cylinder side, and a torsion bar connecting the input shaft and the output shaft.
The power steering apparatus, wherein the steering shaft driving unit applies torque to the input shaft side. The power steering apparatus according to claim 2,
The environmental information detection means detects a driver's doze or side-view driving. The power steering apparatus according to claim 2,
The supply amount and supply direction of the hydraulic pressure supplied from the pump to the pair of hydraulic chambers of the hydraulic power cylinder are selected based on the twist amount and twist direction of the input shaft and output shaft connected to the torsion bar. A power steering device further comprising a rotary valve. The power steering apparatus according to claim 4, wherein
The environmental information detection means detects a relative position between the traveling road and the vehicle,
The hydraulic pressure control unit drives and controls the steering shaft driving unit based on an output signal of the environmental information detection unit so that the vehicle does not deviate from the traveling road. The power steering apparatus according to claim 1, wherein
The steering shaft drive unit is provided with an inclined surface provided on an outer periphery of the steering shaft, a piston member provided on an outer peripheral side of the inclined surface, and driven to rotate the steering shaft by being pressed by the inclined surface; A power steering device comprising: a fluid pressure introducing unit that introduces a fluid pressure from the fluid pressure control unit to the piston member. The power steering apparatus according to claim 6, wherein
The power steering device, wherein the piston member has a curved contact portion with the inclined surface. The power steering apparatus according to claim 6, wherein
The power steering device according to claim 1, wherein the inclined surface further includes a restricting portion that restricts rotation of the steering shaft beyond a predetermined angle. The power steering apparatus according to claim 1, wherein
The steering shaft drive unit
A first inclined surface provided on the outer periphery of the steering shaft, and a left rotation provided on the outer peripheral side of the first inclined surface and driven to rotate the steering shaft in the forward direction by being pressed by the first inclined surface. A piston member for generating directional torque;
A second inclined surface provided on the outer periphery of the steering shaft, and a right rotation provided on the outer peripheral side of the second inclined surface and driving the steering shaft in a reverse direction by being pressed by the second inclined surface. A piston member for generating directional torque;
A power steering device comprising: The power steering apparatus according to claim 9, wherein
The environmental information detection means detects a driver's doze or side-view driving,
The hydraulic pressure control unit alternately supplies hydraulic pressure to the first hydraulic pressure introduction unit and the second hydraulic pressure introduction unit when the environmental information detection unit detects a driver's dozing or side-view driving. Power steering device. The power steering apparatus according to claim 9, wherein
The environmental information detection means detects a relative position between the traveling road and the vehicle,
The fluid pressure control unit selectively supplies fluid pressure to the first fluid pressure introduction unit or the second fluid pressure introduction unit based on a relative position between the traveling path and the vehicle detected by the environment information detection unit. A power steering device characterized by that. The power steering apparatus according to claim 1, wherein
The hydraulic pressure control unit includes a solenoid driven based on an output signal from the environmental information detection unit, and a control valve connected to the solenoid and controlling the hydraulic pressure from the pump to the steering shaft driving unit. A power steering device characterized by comprising. The power steering apparatus according to claim 12,
The power steering device, wherein the solenoid and the control valve are provided coaxially and parallel to the steering shaft. A housing;
An input shaft connected to the steering wheel;
A piston housed in the housing and separating the interior of the housing into a first pressure chamber and a second pressure chamber;
A conversion mechanism that converts rotation of the input shaft into axial movement of the piston;
A rotary valve for selectively supplying hydraulic oil supplied from an external hydraulic source to the first pressure chamber and the second pressure chamber;
A transmission mechanism for transmitting the axial movement of the piston to the steering shaft;
A pump for supplying hydraulic pressure to the first pressure chamber or the second pressure chamber;
A steering shaft drive unit that applies torque to the input shaft by hydraulic pressure from the pump;
Environmental information detection means for detecting vehicle, driver or road information;
A power steering apparatus comprising: a hydraulic pressure control unit that controls a hydraulic pressure supplied to the steering shaft driving unit based on an output signal of the environmental information detection means. In the control method of the power steering device,
A first step of detecting vehicle, driver or road information;
A second step of controlling a hydraulic pressure from an external hydraulic source by an electromagnetic valve based on the detection result of the first step;
A third step of supplying the hydraulic pressure controlled in the second step to a steering shaft drive provided on the steering shaft;
The steering shaft drive unit to which hydraulic pressure is supplied in the third step includes a fourth step of driving the steering shaft. In the control method of the power steering device according to claim 15,
A control method for a power steering device, wherein when a driver's doze or a side-view driving is detected in the first step, the electromagnetic valve is driven and controlled to vibrate the steering shaft in the second step. In the control method of the power steering device according to claim 15,
When the deviation of the vehicle from the lane is detected in the first step, the electromagnetic valve is driven and controlled so that the steering shaft is steered toward the center of the lane in the second step. Control method. In the control method of the power steering device according to claim 15,
A control method for a power steering device, wherein the electromagnetic valve is driven and controlled in the second step according to the vehicle speed detected in the first step, and a steering load applied to the drive shaft is variably controlled. . The power steering apparatus control method according to claim 18,
The method of controlling a power steering device, wherein the electromagnetic valve is driven and controlled so that the steering load applied to the steering shaft in the second step increases as the vehicle speed detected in the first step increases. .

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