JPH1016802A - Steering control device for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicular steering control device capable of not only obtaining a prescribed pre-set load but also a smooth and good feering feeling without needing any high assembling position accuracy. SOLUTION: For a control valve 10, a first groove part 42 is formed at least in one spot of a ring 40 fixed to a valve body 14 and a second groove part 50 is formed in a ring 44 connected to a valve shaft 16 by a spring 46. A ball 52 is held between the grooves. The spring 46 is set to have high twist rigidity and displaced in a diameter direction. Thus, even if a difference occurs in assembling positions between the first and second groove parts 42 and 50, this difference is absorbed by the displacement of the ring 44 in a diameter direction and, consequently, a good steering feeling having no level difference is provided in a steering initial time until steering torque reaches a pre-set load.

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 to a vehicle steering control having a hydraulic control valve for controlling supply and discharge of a hydraulic pressure by a relative displacement between a valve shaft and a valve body. Related to the device.

[0002]

2. Description of the Related Art As a steering control device for a vehicle such as an automobile (for example, a hydraulic power steering device), a power steering device having a hydraulic control valve is known (for example, Japanese Patent Application Laid-Open No. 2-106467). ).

[0003] In the power steering apparatus disclosed in this publication, the hydraulic control valve is a so-called rotary valve having a valve shaft and a valve body, and the hydraulic pressure is supplied by the relative displacement between the valve shaft and the valve body. Discharge control can be performed. Further, in this hydraulic control valve, three V-shaped grooves are provided at equal intervals in the circumferential direction in a portion facing the valve shaft (a ring member integrally attached to the valve shaft) and the valve body. A ball is inserted into each groove. Further, each ball is pressed and urged by a spring provided on a valve shaft (ring member), and is held in each V-shaped groove.

When the valve shaft is rotated by steering, the balls held in the respective V-shaped grooves need to move in these grooves, so that the balls start to move in the grooves. Is applied as an initial steering force (preset load) at the start of steering.

However, in the power steering apparatus using such a hydraulic control valve, as described above, the ball and the V-shaped groove for applying the initial steering force (preset load) at the start of the steering are formed by the valve shaft and the valve body. Since three positions are provided at equal intervals in the circumferential direction in the opposing portion of each other, if the positioning (position accuracy) of each ball and the V-shaped groove is not performed accurately, the ball moves in the groove. The force changes discontinuously, causing a sense of step in the steering force.
That is, as shown in FIG. 5, the characteristic of the relative displacement angle θ-steering torque T changes in a stepped manner from the start of steering (T = 0) to the time when the preset load (T = T ₀ ) is reached. For this reason, there was a problem that the steering feeling deteriorated.

[0006]

In view of the above facts, the present invention not only can obtain a predetermined preset load, but also can provide a good steering without stepping feeling without requiring high assembly position accuracy. It is an object of the present invention to provide a vehicle steering control device that can provide a feeling.

[0007]

According to a first aspect of the present invention, there is provided a steering control device for a vehicle, which is disposed in the middle of a steering mechanism for mechanically connecting a steering wheel and a steering wheel. A hydraulic control valve for controlling supply / discharge of hydraulic pressure by a hydraulic control valve for controlling hydraulic fluid from a hydraulic source by the hydraulic control valve, wherein at least one is provided on an axial end surface of the valve body. A first groove portion, an annular member provided to face an axial end surface of the valve body and opposed to the first groove portion, the annular member being displaceable in a radial direction, and the first groove portion; A spherical body sandwiched between the second groove portion and one end integrally connected to the valve shaft and the other end integrally connected to the annular member; Torsional rigidity for urging the end face is characterized by including biasing means high, the.

In the vehicle steering control device according to the first aspect, the valve shaft and the valve body of the hydraulic control valve are relatively displaced in accordance with the steering of the steering wheel, whereby the hydraulic pressure of the hydraulic fluid from the hydraulic source is supplied. The discharge is controlled.

In this case, a spherical body is sandwiched between the first groove provided on the axial end face of the valve body and the second groove of the annular member. When the valve shaft is rotated by the steering of the steering wheel, the spheres held in the first groove and the second groove need to move in these grooves. The force to start moving inside acts as an initial steering force (preset load) at the start of steering.

Here, at least one of the first groove, the second groove, and the spherical body for applying the initial steering force (preset load) at the time of starting the steering is provided at at least one portion opposing the valve shaft and the valve body. Since the annular member can be displaced in the radial direction and the biasing means has a high torsional rigidity, the annular member is temporarily located at the position where the first groove and the second groove are assembled. Even if an error occurs, the annular member is displaced in the radial direction and is absorbed. As a result,
The force for the spherical body to move in the first groove portion and the second groove portion changes continuously, and there is no stepped feeling in the steering force. That is, the characteristic of the relative displacement angle θ-the steering torque T is
Preset load (T = T ₀ ) from the start of steering (T = ₀ )
, And thus the steering feeling does not deteriorate.

As described above, in the vehicle steering control device, not only a predetermined preset load can be obtained, but also a good steering feeling without stepping feeling without requiring high assembly position accuracy. be able to.

[0012]

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

The vehicular steering control device includes a control valve 10. The control valve 10 has a cylindrical valve housing 12, and a valve body 14 is disposed in the valve housing 12 so as to be relatively rotatable. The valve body 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.

The valve body 14 includes a valve shaft 1.
6 are fitted so as to be relatively rotatable. The valve shaft 16 is connected to an input shaft connected to a steering wheel (not shown).

A torsion bar 18 is arranged at the axis 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 steering wheel, the pinion shaft 15 is rotated.
A relative angular displacement is generated between the valve body 14 connected to the input shaft and the valve shaft 16 connected to the input shaft.

An annular groove 2 is formed on the outer peripheral surface of the valve body 14.
0A, 20B and 20C are formed at predetermined intervals in the axial direction, the central annular groove 20B is connected to a hydraulic pump (not shown) via a hydraulic circuit, and the upper annular groove 20A is a power cylinder (not shown). For example, the lower annular groove 20C in the axial direction is connected to, for example, a left oil chamber of the power cylinder.

As shown in FIG. 3, on the inner peripheral surface of the valve body 14, a land portion 22 and a concave groove 24 extending in the axial direction are formed.
They are formed alternately along the circumferential direction. A pressure oil hole 26 for introducing hydraulic pressure from a hydraulic pump into the control valve 10 through a central annular groove 20 </ b> B is formed through the valve body 14 in the radial direction of the land 22. In addition, a suction / discharge oil hole 28 communicating with one annular groove 20A for sucking / discharging oil pressure in, for example, a right oil chamber of the power cylinder is formed in one concave groove 24 adjacent to the pressure oil hole 26, and for example, on the left of the power cylinder. The oil suction / discharge oil hole 30 communicating with the other annular groove 20C for sucking / discharging the oil pressure into / from the oil chamber is formed as the pressure oil hole 26
Is formed in the other concave groove 24 adjacent to.

Also, 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 3 for guiding pressure oil to an inner peripheral space 38 of the valve shaft 16 is formed in a concave groove 34 facing the land portion 22 where the pressure oil hole 26 of the valve body 14 is not formed.
6 are formed through.

Further, a return oil hole 19 for guiding pressure oil to a reservoir tank (not shown) is formed through the valve shaft 16 at a portion not corresponding to the valve body 14.

The valve shaft 16 and the valve body 1
4 indicates that when the torsion bar 18 is not twisted (the steering is in a neutral state), the concave groove 24 of the valve body 14 and the land 32 of the valve shaft 16
As shown in the figure, the center parts in the circumferential direction are aligned and opposed,
A predetermined gap 39 is formed between the land 32 and the land 22 of the valve body 14 on both sides in the circumferential direction. This gap 39 becomes a throttle when the valve shaft 16 and the valve body 14 rotate relative to each other.

On the other hand, as shown in detail in FIG. 2, a ring 40 is integrally fixed to the upper end surface in the axial direction of the valve body 14, and a V-shaped first groove 42 is formed in the ring 40. One place is formed. Also, this ring 4
A ring 44 as an annular member is disposed around the valve shaft 16 so as to face the valve shaft 0. One end of a spring 46 as urging means is connected to the ring 44, and the other end of the spring 46 is connected and fixed to a flange 48 provided on the valve shaft 16.

Here, the spring 46 is a coil spring, and has a sufficiently high torsional rigidity and a relatively low bending rigidity. For this reason, the spring 4
The ring 44 connected and held by 6 rotates integrally with the valve shaft 16 and is constantly urged toward the ring 40, and is displaceable in the radial direction.

In the ring 44 held as described above, a V-shaped second groove 50 is formed so as to face the first groove 42 of the ring 40.

The first groove 42 of the ring 40 and the ring 44
The ball 52 is disposed between the second groove 50 and the second groove 50. The ball 52 is pressed and urged between the ring 40 and the ring 44 by the urging force of the spring 46, and is held in the first groove 42 and the second groove 50.

Next, the operation of the present embodiment will be described. In the control valve 10 (vehicle steering control device) having the above-described configuration, the pressure oil supplied from the hydraulic pump is diverted by the diverter valve, and then is passed through the central annular groove 20B and the pressure oil hole 26 of the control valve 10. It is introduced into the concave groove 34 of the valve shaft 16 and is introduced into the concave groove 24 of the valve body 14 adjacent on both sides through the gap 39 on both sides in the circumferential direction of the concave groove 34. The pressure oil introduced into the groove 24 is introduced into the groove 34 communicated with the communication oil hole 36 through a gap 39 on the side of the groove 24 opposite to the groove 34, and the communication oil hole 3 is formed.
6. Returned to the reservoir tank via the inner peripheral space 38.

When the steering is in a neutral state,
Since the torsion bar 18 is not twisted, the opening areas of the gaps 39 located on both circumferential sides of the concave groove 34 facing the pressure oil hole 26 are equal as shown in FIG. At this time, no pressure difference occurs 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 right oil chamber and the pressure in the left oil chamber of the power cylinder become equal, No assist force is generated in the power cylinder.

When the steering wheel is rotated and the torsion bar 18 is twisted, the valve body 14
Relative angular displacement occurs between the valve shaft 16 and the valve shaft 16, resulting in a difference in the opening area of the gap 39 on both circumferential sides 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.

Here, a first groove 42 provided on an axial end surface (ring 40) of the valve body 14 and a ring 4 are provided.
A ball 52 is sandwiched between the second groove 50 and the second groove 50. When the valve shaft 16 is rotated by steering, the ball 52 held in the first groove 42 and the second groove 50 needs to move in these grooves. The force for starting to move in the box acts as an initial steering force (preset load) at the start of steering.

In this case, the first groove 42, the second groove 50, and the ball 52 for applying the initial steering force (preset load) at the start of the steering are opposed to the valve shaft 16 and the valve body 14. Since the ring 44 can be displaced in the radial direction and the spring 46 has a high torsional rigidity, the first groove 42 and the second groove 50 Even if an error occurs in the assembly position, the ring 44 is displaced in the radial direction and is absorbed.

As a result, the force for the ball 52 to move in the first groove portion 42 and the second groove portion 50 changes continuously, and there is no stepped feeling in the steering force. That is, as shown in FIG. 4, the characteristic of relative displacement angle θ-steering torque T is
Preset load (T = T ₀ ) from the start of steering (T = ₀ )
, And thus the steering feeling does not deteriorate.

As described above, with the control valve 10 (vehicle steering control device), not only can a predetermined preset load be obtained, but also a good assembling feeling can be obtained without requiring high assembly position accuracy. A steering feeling can be obtained.

In the above-described embodiment, the spring 46 as the urging means has been described as a coil spring. However, the urging means is not limited to this, and for example, a bellows-shaped spring may be used. The use of such a bellows-like spring is preferable because characteristics of sufficiently high torsional rigidity and relatively low flexural rigidity can be easily set.

In the above embodiment, the axial end surface (ring 40) of the valve body 14 and the ring 4
4 is provided with a first groove portion 42 and a second groove portion 50, respectively, but is not limited thereto, and a plurality of groove portions may be arranged at predetermined intervals in the circumferential direction. Good. In this case, if the gap between the axial end surface (ring 40) of the valve body 14 and the groove provided in the ring 44 can be formed with high precision, the ring 44 is displaced in the radial direction at the time of assembly. Can be lowered.

[0034]

As described above, the vehicle steering control device according to the present invention not only can obtain a predetermined preset load, but also does not require a high assembling position accuracy and does not have a stepped feeling. It has an excellent effect that a good steering feeling can be obtained.

[Brief description of the drawings]

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

FIG. 2 is a front view showing a relationship among a first groove, a second groove, and a ball of the control valve according to the embodiment of the present invention.

FIG. 3 is a schematic half sectional view taken along a direction perpendicular to the axis of the control valve according to the embodiment of the present invention.

FIG. 4 is a diagram showing characteristics of relative displacement angle θ-steering torque T by a control valve according to the embodiment of the present invention.

FIG. 5 is a graph showing characteristics of a relative displacement angle θ-steering torque T by a conventional control valve (vehicle steering control device).

[Explanation of symbols]

 Reference Signs List 10 control valve (vehicle steering control device) 12 valve housing 14 valve body 16 valve shaft 18 torsion bar 40 ring 42 first groove 44 ring (annular member) 46 spring (biasing means) 50 second groove 52 ball ( Sphere)

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Miyuki Ouchi 1 Toyota Town, Toyota City, Aichi Prefecture Inside Toyota Motor Corporation (72) Inventor Shoji Yamashita 1 Toyota Town, Toyota City, Aichi Prefecture Inside Toyota Motor Corporation (72) Inventor Masaaki Chiga 1 Toyota Town, Toyota City, Aichi Prefecture Toyota Motor Corporation (72) Inventor Hiromitsu Kageyama 1 Toyota Town, Toyota City, Aichi Prefecture Toyota Motor Corporation

Claims (1)

[Claims] A hydraulic control valve disposed in a steering mechanism for mechanically connecting a steering wheel and a steered wheel to supply and discharge hydraulic pressure by a relative displacement between a valve shaft and a valve body; A steering control device for a vehicle that controls the oil liquid by the hydraulic control valve, wherein at least one first groove portion is provided on an axial end surface of the valve body, and the first groove portion is provided to face the axial end surface of the valve body. An annular member formed with a second groove portion facing the first groove portion and capable of being displaced in a radial direction; a spherical body sandwiched between the first groove portion and the second groove portion; Biasing means having a high torsional rigidity integrally connected to the valve shaft and having the other end integrally connected to the annular member and constantly biasing the annular member toward the axial end surface of the valve body. Equipment The vehicle steering control apparatus characterized by the.