JPH09254801A - Vehicle steering control device - Google Patents

Abstract

(57) Abstract: A vehicle steering control device that can selectively switch between a manual steering mode and an automatic steering mode and that can be provided at a low cost with a simple structure. In a vehicle steering control device 70, a control valve 1 is provided.
The hydraulic chamber 50 and the hydraulic chamber 51 provided in the steering reaction force control unit 40 of 0 are provided with a pair of plungers that are opposed to each other in the biasing direction and generate a steering reaction force. Also,
A direction switching valve 56 is connected to the hydraulic chamber 50 and the hydraulic chamber 51, and the oil liquid from the flow dividing valve 54 can be independently supplied. In the manual steering mode, the hydraulic pressure is evenly supplied to both the hydraulic chamber 50 and the hydraulic chamber 51 to operate as a hydraulic reaction force type power steering device. In the automatic steering mode,
By the switching control of the direction switching valve 56, the hydraulic pressure is supplied to one of the hydraulic chambers corresponding to the steering direction, and automatic steering can be realized.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steering control device for a vehicle such as an automobile, and more particularly, it can selectively switch between a manual steering mode in which steering is performed manually and an automatic steering mode in which steering is performed automatically. The present invention relates to a vehicle steering control device.

[0002]

2. Description of the Related Art In a steering control device for a vehicle such as an automobile (for example, a hydraulic power steering device), steering is performed by detecting a manual steering mode in which a driver operates a steering wheel and a running state of the vehicle. There is a power steering device capable of selectively switching between automatic steering mode and automatic steering mode (for example, Japanese Patent Laid-Open No. 62-43).
361 publication).

[0003] The power steering apparatus disclosed in this publication includes a hydraulic actuator for steering a steered wheel, and a hydraulic steering system for steering by distributing and controlling the hydraulic pressure from a hydraulic pump by operating a steering wheel. In the mode, the steering wheel is steered by supplying hydraulic pressure from the automatic steering hydraulic system.

However, this power steering apparatus is provided with an automatic steering hydraulic system used in an automatic steering mode, in addition to a hydraulic steering system used in a normal operation (manual steering mode in which steering is performed by steering). Therefore, the configuration of the hydraulic circuit and the like is complicated as a whole, and there is a problem in terms of arrangement space and cost.

[0005]

In view of the above facts, the present invention not only can selectively switch between the manual steering mode and the automatic steering mode, but also has a simple structure and can be provided at low cost for vehicle steering control. The purpose is to obtain a device.

[0006]

According to a first aspect of the present invention, there is provided a vehicle steering control device, which detects a manual steering mode in which steering is performed by a driver operating a steering wheel and a running state of the vehicle to automatically perform steering. A vehicle steering control device capable of selectively switching between an automatic steering mode to be performed and a steering mechanism that mechanically connects a steering wheel and a steering wheel, and a hydraulic control valve disposed in the middle of the steering mechanism. An assist mechanism that controls oil liquid from a hydraulic pressure source by the hydraulic pressure control valve to obtain a steering assist force according to a steering torque,
It is provided in the middle of the steering mechanism in association with the hydraulic control valve of the assist mechanism, and is energized by the oil liquid from the hydraulic source to apply a steering reaction force to the steering mechanism and separate and independent from each other and the reaction force direction. Has a pair of plungers opposed to each other, and supplies the hydraulic pressure evenly to the pair of plungers of the steering reaction force mechanism based on the steering reaction force mechanism that controls the reaction force applied to the steering force and the selected steering mode. And a hydraulic pressure switching means for switching and controlling the hydraulic pressure depending on the steering direction and supplying the hydraulic pressure to one of the plungers based on the steering direction.

In the vehicle steering control device according to the first aspect, in the manual steering mode in which the steering wheel is operated by the driver, when the steering wheel is operated, the steering wheel is steered by the steering mechanism. A steering assist force corresponding to the steering torque is applied by the assist mechanism. Further, in this manual steering mode, the hydraulic pressure is evenly supplied to the pair of plungers of the steering reaction force mechanism by the operation of the hydraulic pressure switching means, whereby a predetermined reaction force is applied to the steering force of the steering mechanism, and the steering force is stabilized. A steering feeling is obtained.

On the other hand, in the automatic steering mode in which the running state of the vehicle is detected and the steering is automatically performed, the hydraulic pressure is applied to one of the plungers corresponding to the left and right steering directions by the operation of the hydraulic pressure switching means. Supplied. For this reason,
The hydraulic control valve of the assist mechanism is operated in cooperation with the biasing force of one of the selected (hydraulic pressure supplied) plungers, and the steering force is applied to the steering mechanism to steer the steered wheels.

As described above, the manual steering mode and the automatic steering mode can be selectively switched only by controlling the switching of the hydraulic pressure supply to the pair of plungers of the steering reaction force mechanism by the hydraulic pressure switching means. Is easy and cheap.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows the overall configuration of a vehicle steering control device 70 according to an embodiment of the present invention.

The vehicle steering control device 70 includes a control valve 10 which constitutes an assist mechanism and a steering reaction force mechanism. As shown in detail in FIG. 2, the control valve 10 has a cylindrical valve housing 12, and a valve sleeve 14 is disposed in the valve housing 12 so as to be relatively rotatable. The valve sleeve 14 has a cylindrical shape, and is connected to a pinion shaft 15 (output shaft) via a pin 17 so as to be integrally rotatable.

A valve shaft 16 is fitted in the valve sleeve 14 so as to be relatively rotatable. The valve shaft 16 is connected to an input shaft (not shown).

A torsion bar 18 is arranged at the axial center of the valve shaft 16. One end of the torsion bar 18 is connected to the input shaft, and the other end is connected to the pinion shaft 15. That is, the input shaft is connected to the pinion shaft 15 via the torsion bar 18, and when the torsion bar 18 is twisted by the turning operation of the stearing, the input shaft and the valve sleeve 14 connected to the pinion shaft 15 are input. A relative angular displacement is generated between the valve shaft 16 and the valve shaft 16 connected to the shaft.

On the outer peripheral surface of the valve sleeve 14, annular grooves 20A, 20B and 20C are formed at predetermined intervals in the axial direction, and the central annular groove 20B is connected to a hydraulic pump 52 via a hydraulic circuit which will be described in detail later. The axially upper annular groove 20A is connected to, for example, an oil chamber on the right side of a power cylinder (not shown), and the annular groove 20C on the axially lower side is connected to, for example, an oil chamber on the left side of the power cylinder. .

As shown in FIG. 5, on the inner peripheral surface of the valve sleeve 14, axially extending land portions 22 and concave grooves 24 are formed alternately along the circumferential direction. A pressure oil hole 26 for introducing the hydraulic pressure from the hydraulic pump 52 into the control valve 10 via the central annular groove 20B is formed in the valve sleeve 14 in the radial direction of the land portion 22. Further, a suction / discharge oil hole 28 communicating with one annular groove 20C for sucking / discharging hydraulic pressure to / from the power cylinder, for example, is formed in the concave groove 24, and the other suction / discharging hydraulic oil is sucked / discharged to / from, for example, the left oil chamber of the power cylinder. An oil drainage hole 30 communicating with the annular groove 20B is formed in the concave groove 24.

On the other hand, on the outer peripheral surface of the valve shaft 16,
The land portions 32 and the concave grooves 34 extending in the axial direction are alternately formed along the circumferential direction. In the valve shaft 16, a communication oil hole 36 for guiding pressure oil to the inner peripheral space 38 of the valve shaft 16 penetrates through a concave groove 34 facing the land portion 22 where the pressure oil hole 26 of the valve sleeve 14 is not formed. Is formed.

Further, as shown in FIG. 2, the valve shaft 16 has a return oil hole 1 for guiding pressure oil to a reservoir tank 21 (see FIG. 1) at a portion not corresponding to the valve sleeve 14.
9 are formed through.

With respect to the valve shaft 16 and the valve sleeve 14, the concave groove 24 of the valve sleeve 14 and the land portion 32 of the valve shaft 16 are shown in FIG. 5 when the torsion bar 18 is not twisted (the steering is in a neutral state). As shown, they are opposed to each other with their center portions in the circumferential direction aligned with each other.
A predetermined gap 39 is formed between the second land portion 22 and the fourth land portion 22. This gap 39 is provided in the valve shaft 1
When the valve sleeve 6 and the valve sleeve 14 rotate relative to each other, it becomes a throttle portion.

Further, as shown in FIG. 2, a steering reaction force control section 40 as a steering reaction force mechanism is provided in the valve housing 12 below the valve sleeve 14. The steering reaction force control unit 40 includes a plunger retainer 42 into which the lower end of the valve shaft 16 is fitted.

As shown in FIGS. 3 and 4, the plunger retainer 42 is formed with a pair of recesses 48 and a pair of recesses 49 on the outer peripheral side, and between the recess 48 and the valve housing 12. The hydraulic chamber 50 is formed and the recess 49 is formed.
A hydraulic chamber 51 is formed between the valve housing 12 and the valve housing 12. That is, by the plunger holder 42, the hydraulic chamber 50 and the hydraulic chamber 51 that are separated and independent from each other along the axial direction are provided.
Are formed.

Further, two plungers 46 are slidably held in the plunger holder 42 corresponding to one hydraulic chamber 50. These plungers 46 are located diagonally to each other in a cross section orthogonal to the device axis, and one side surface faces the hydraulic chamber 50. A protrusion 46A is provided on the opposite side of each plunger 46 from the hydraulic chamber 50.
Are formed, and face each side surface of a pair of flat blades 44 formed at the lower end of the valve shaft 16. Therefore, in the plunger 46, the protrusion 46 </ b> A presses the wing portion 44 when the pressure in the hydraulic chamber 50 rises. In this case, since the two plungers 46 are diagonally located in a cross section orthogonal to the device axis, the directions in which the blades 44 are pressed are the same (CW direction in FIG. 3).

Further, two plungers 47 are slidably held in the plunger holder 42 corresponding to the other hydraulic chamber 51. These plungers 47
They are located diagonally to each other in a cross section orthogonal to the apparatus axis, and are located diagonally opposite to the plunger 46 described above, and one side surface faces the hydraulic chamber 51. A protrusion 47A is provided on the opposite side of each plunger 47 from the hydraulic chamber 51.
Are formed, and face each side surface of the pair of wings 44 formed at the lower end of the valve shaft 16. Therefore, in the plunger 47, the protrusion 47 </ b> A presses the wing portion 44 due to the pressure increase in the hydraulic chamber 51. Also in this case, since the two plungers 47 are diagonally located in a cross section orthogonal to the device axis, the directions in which the blades 44 are pressed are the same. Further, since these plungers 47 are located diagonally opposite to the plunger 46, the plunger 46 is not
The wing portion 44 is pressed in the direction opposite to the direction in which the blade 4 is pressed (CCW direction in FIG. 4).

The control valve 10 having the above structure is connected to a hydraulic circuit as shown in FIG. In this hydraulic circuit, the annular groove 20B of the control valve 10 (the pressure oil hole 26 of the valve sleeve 14) is connected to the hydraulic pump 52 via the flow dividing valve 54, and the return oil hole 19 of the control valve 10 is connected. It is connected to the reservoir tank 21. Therefore, the oil liquid discharged from the hydraulic pump 52 is divided by the flow dividing valve 54, part of which is supplied to the control valve 10 (the valve sleeve 14 and the valve shaft 16) and is returned to the reservoir tank 21. .

Further, a directional switching valve 56 as hydraulic pressure switching means is connected to the flow dividing valve 54. Further, the directional switching valve 56 is a hydraulic pressure provided in the steering reaction force control section 40 of the control valve 10. The chamber 50 and the hydraulic chamber 51 are independently connected. Therefore, the oil liquid discharged from the hydraulic pump 52 is divided by the flow dividing valve 54 and supplied to the direction switching valve 56. Direction switching valve 56
6A shows a state in which the oil liquid fed from the flow dividing valve 54 is evenly supplied to the hydraulic chamber 50 and the hydraulic chamber 51 as shown in FIG. 6A, and FIG. The switching operation can be performed in a state in which the oil liquid thus fed is supplied to one of the hydraulic chambers.

Further, a solenoid valve 58 is connected to the flow dividing valve 54. This solenoid valve 58
The flow dividing valve 5 is activated by changing the flow passage throttle area.
4 (in other words, the amount of oil liquid that the flow dividing valve 54 divides and supplies to the direction switching valve 56) can be controlled, and the reaction force pressure of the steering reaction force control unit 40 can be controlled accordingly. can do.

Further, the diversion valve 54 has a fixed orifice 6
0 is connected in parallel in a hydraulic circuit. The fixed orifice 60 allows the oil liquid to flow to the direction switching valve 56 side (that is, the steering reaction force control section 4 when the pressure on the annular groove 20B side of the control valve 10 (the pressure oil hole 26 of the valve sleeve 14) increases).
It has a role of flowing to the 0 side).

A controller 62, which constitutes hydraulic pressure switching means, is connected to the solenoid valve 58 and the direction switching valve 56 of the hydraulic circuit configured as described above. A vehicle speed signal from a vehicle speed sensor (not shown) and a mode signal of the selected steering mode (manual steering mode or automatic steering mode) are input to the controller 62.
As a result, the controller 62 controls the drive of the solenoid valve 58 according to the vehicle speed, and further controls the switching of the direction switching valve 56 based on the selected steering mode (manual steering mode or automatic steering mode) and the automatic steering. Direction switching valve 56 according to the steering direction in the mode
This is a configuration in which the switching can be controlled.

Next, the operation of the present embodiment will be described. First, a case will be described in which the vehicle steering control device 70 is operated in a manual steering mode in which steering is performed by a driver operating a steering wheel.

In this manual steering mode, the controller 6
The direction switching valve 56 is switched by the switching control according to 2 so that the oil liquid fed from the flow dividing valve 54 is uniformly supplied to the hydraulic chamber 50 and the hydraulic chamber 51 as shown in FIG. 6 (A).

Here, the pressure oil supplied from the hydraulic pump 52 is diverted by the shunt valve 54, and then the control valve 1
0 through the annular groove 20B at the center and the pressure oil hole 26 into the concave groove 34 of the valve shaft 16, and the concave grooves of the valve sleeve 14 that are adjacent to both sides through the gaps 39 on both sides in the circumferential direction of the concave groove 34. Introduced in 24. The pressure oil introduced into the concave groove 24 is introduced into the concave groove 34 communicated with the communicating oil hole 36 through the gap 39 on the opposite side of the concave groove 24 in the concave groove 24, and the communicating oil hole 36, It is returned to the reservoir tank 21 via the inner peripheral space 38.

When the steering is in the neutral state,
Since the torsion bar 18 is not twisted, the opening areas of the gaps 39 located on both sides in the circumferential direction of the concave groove 34 facing the pressure oil hole 26 are equal as shown in FIG. At this time, there is no pressure difference between the concave grooves 24 on both sides of the land portion 22 in which the pressure oil hole 26 is formed, and the pressure in the oil chamber on the right side of the power cylinder becomes equal to the pressure in the oil chamber on the left side of the power cylinder. No assist force is generated in the power cylinder.

When the steering wheel is rotated and the torsion bar 18 is twisted, the valve sleeve 1
A relative angular displacement occurs between the valve groove 4 and the valve shaft 16, and a difference occurs in the opening area of the gap 39 on both sides in the circumferential direction of the concave groove 34. As a result, one gap 39 (a gap on the opposite side in the rotation direction) is narrowed between the concave grooves 24 on both sides of the land portion 22 in which the pressure oil hole 26 is formed, so that a pressure difference is generated, and the power connected to these is reduced. A pressure difference also occurs between the two oil chambers of the cylinder, and an assist force is generated in the steering direction.

Further, as the vehicle speed increases, the solenoid valve 58 is drive-controlled to increase the amount of oil fed from the flow dividing valve 54 to the direction switching valve 56, and the steering reaction force control section 40
The reaction force pressure applied to (the hydraulic chamber 50 and the hydraulic chamber 51) is increased. As a result, the plunger 46 and the plunger 47 are
The reaction force due to increases. Therefore, as the steering force, since the reaction force by the plunger 46 or the plunger 47 acts in addition to the twisting torque of the torsion bar 18, a stable steering feeling with a feeling of response can be obtained.

On the other hand, in the automatic steering mode in which the traveling state of the vehicle is detected and the steering is automatically performed, the direction switching valve 56 is switched by the switching control by the controller 62 based on the automatic steering signal, as shown in FIG. Alternatively, as shown in FIG. 6C, the hydraulic fluid supplied from the flow dividing valve 54 is supplied to any one of the hydraulic chambers 50 and 51 corresponding to the left and right steering directions.

Therefore, the plunger (plunger 46 or plunger 47) of either one of the hydraulic chambers 50 and 51 (the hydraulic pressure is supplied) is selected.
The torsion bar 18 is twisted by the urging force of.
When the torsion bar 18 is twisted, a relative angular displacement is generated between the valve sleeve 14 and the valve shaft 16 as described above, and a pressure difference is also generated between the oil chambers of the power cylinder to steer in the steering direction. Force is generated and the steered wheels are steered.

As described above, the supply of the hydraulic pressure to the plunger 46 or the plunger 47 of the steering reaction force control section 40 (the hydraulic chamber 50 and the hydraulic chamber 51) constituting the steering reaction force mechanism is controlled by the direction switching valve 56. Only by this, it is possible to selectively switch between the manual steering mode and the automatic steering mode, and in the automatic steering mode, the automatic steering according to the traveling state of the vehicle can be realized by the switching control of the direction switching valve 56. Therefore, there is no need to provide an automatic steering hydraulic system used in the automatic steering mode, and the structure is simple and inexpensive.

[0037]

As described above, the vehicle steering control device according to the present invention can not only selectively switch between the manual steering mode and the automatic steering mode, but also has a simple structure and can significantly reduce the cost. It has an excellent effect that it can be achieved.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of a vehicle steering control device according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along the axis of the control valve applied to the vehicle steering control device according to the embodiment of the present invention.

FIG. 3 is a cross-sectional view (a cross-sectional view taken along line 3-3 of FIG. 2) perpendicular to the axis of the steering reaction force control unit of the control valve applied to the vehicle steering control device according to the embodiment of the present invention.

FIG. 4 is a cross-sectional view (a cross-sectional view taken along line 4-4 in FIG. 2) perpendicular to the axis of the steering reaction force control unit of the control valve applied to the vehicle steering control device according to the embodiment of the present invention.

FIG. 5 is a schematic half cross-sectional view (a cross-sectional view taken along line 5-5 of FIG. 2) perpendicular to the axis of the control valve applied to the vehicle steering control device according to the embodiment of the present invention.

FIG. 6 is a schematic configuration diagram showing an operating state of a directional control valve applied to the vehicle steering control device according to the embodiment of the present invention.

[Explanation of symbols]

 10 Control Valve 12 Valve Housing 14 Valve Sleeve 16 Valve Shaft 18 Torsion Bar 40 Steering Reaction Force Control Section 44 Wing 46 Plunger 47 Plunger 50 Hydraulic Chamber 51 Hydraulic Chamber 52 Hydraulic Pump (Hydraulic Source) 54 Dividing Valve 56 Directional Valve (Hydraulic) Switching means) 58 Solenoid valve 62 Controller (hydraulic pressure switching means) 70 Vehicle steering control device

Claims (1)

[Claims] 1. A vehicle steering control device capable of selectively switching between a manual steering mode in which steering is performed by a driver operating a steering wheel and an automatic steering mode in which steering is automatically performed by detecting a traveling state of the vehicle. A steering mechanism that mechanically connects the steering wheel and the steered wheels, and a hydraulic control valve disposed in the middle of the steering mechanism. The hydraulic fluid is controlled by the hydraulic control valve to control the steering torque. An assist mechanism that obtains a steering assist force in accordance with the steering mechanism, and a hydraulic control valve of the assist mechanism provided in the middle of the steering mechanism in association with the steering mechanism. A steering reaction force mechanism that controls the reaction force applied to the steering force and has a pair of plungers that are independent of each other and have reaction force directions opposite to each other. A hydraulic pressure for switching and controlling the hydraulic pressure supply between a state in which the hydraulic pressure is evenly supplied to the pair of plungers of the steering reaction mechanism based on the mode and a state in which the hydraulic pressure is supplied to one of the plungers based on the steering direction. A vehicle steering control device comprising: a switching unit.