JP2552765Y2 - Hydraulic control valve - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydraulic control valve for controlling hydraulic pressure supplied to two different oil supply destinations in accordance with a relative angular displacement between a valve body and a valve body generated coaxially. In a hydraulic power steering apparatus, the present invention relates to a hydraulic control valve used to control a supply hydraulic pressure to a power cylinder that generates a steering assist force according to a steering operation.

[0002]

2. Description of the Related Art A hydraulic power steering device assists steering by hydraulic pressure generated by a double-acting hydraulic cylinder (power cylinder) disposed in a steering mechanism, and operates a steering wheel (steering wheel) of an automobile. Reduce the labor burden required for
It is intended to obtain a light steering feeling, and in recent years, it is widely used not only in large vehicles such as trucks and buses but also in small vehicles such as ordinary passenger cars.

[0003] This power steering device includes a hydraulic pump (oil pressure source) driven by an engine and an oil tank (oil discharge destination) for storing hydraulic oil, and two cylinder chambers (oil feed destination) of the power cylinder. In the meantime, a hydraulic control valve for controlling the supply and discharge of the hydraulic pressure according to the direction and magnitude of the steering torque applied to the steering wheel is interposed. As this hydraulic control valve, a rotary hydraulic control valve that directly uses the rotation of a steering wheel is generally used. This is a method in which an input shaft connected to a steering wheel and an output shaft connected to a steering mechanism are connected by a torsion. Coaxially connected via a bar,
When a valve body integrally formed at one connection end is fitted to a cylindrical valve body engaged with the other connection end so as to be relatively rotatable coaxially and a steering torque is applied to the steering wheel. ,
The structure is such that relative angular displacement is generated between the valve body and the valve element with the torsion of the torsion bar.

The valve body and the valve body are positioned so that a plurality of lands equally arranged on the inner circumference of the former and the outer circumference of the latter are staggered in the circumferential direction. It is located between the oil supply chamber and the oil discharge chamber respectively connected to the oil pressure source and the oil discharge destination, and the oil discharge chamber on both sides of the oil supply chamber. A pair of oil supply chambers communicated with each other are provided side by side.
These chambers communicate with each other via throttles formed between the corners of the lands opposite each other on both sides, and the areas change in these throttles according to the relative angular displacement. feed hydraulic pressure to the feed oil destination are controlled.

That is, when there is no relative angular displacement between the valve body and the valve body, the oil pressure supplied to the oil supply chamber is equally distributed to the pair of oil supply chambers via the throttle portions on both sides of the oil supply chamber. The oil is introduced into the oil discharge chamber through the throttle section on the other side of the oil supply chamber, and is returned to the oil tank. On the other hand, relative angular displacement occurs between the valve body and the valve body, and the throttles on both sides of the oil supply chamber are restricted. If the throttle areas of the parts are different, the oil pressure supplied to the oil supply chamber is mainly introduced into one oil supply chamber via one throttle part (the side with the increased throttle area), and the oil supply chamber and the other Between the oil chamber,
And a pressure difference occurs between the two cylinder chambers of the power cylinder communicating with each other, and the power cylinder generates an oil pressure corresponding to the pressure difference.

[0006] The pressure difference generated at this time depends on the degree of reduction of the throttle area at the throttle portion on the other side (the side where the throttle area is reduced) of the oil supply chamber, and the degree of this reduction is the magnitude of the relative angular displacement, That is, since the steering torque corresponds to the magnitude of the steering torque applied to the steering wheel, a steering assist force corresponding to the magnitude of the steering torque in the operation direction of the steering wheel is obtained by the hydraulic pressure generated by the power cylinder. In addition, the oil pushed out from the other cylinder chamber with the operation of such a power cylinder flows back to the other oil feed chamber of the hydraulic control valve, and a throttle portion having an increased throttle area on one side of the oil control chamber. A part of the oil introduced into the adjacent oil discharge chamber through the oil supply chamber through the oil supply chamber through the oil supply chamber also has a reflux restriction with a reduced throttle area on the other side of the oil supply chamber. After that, they are introduced into the adjacent oil discharge chambers, and these are both discharged to the oil tank.

Now, in a power steering apparatus which obtains a steering assist force according to the operation of such a hydraulic control valve,
As shown in FIG. 6, a general increasing characteristic of the steering assist force with an increase in the steering torque applied to the steering wheel has a certain region where a substantially constant small steering assist force can be obtained in a small steering torque range. This is a characteristic that shifts to an increase region in which the steering assist force increases with respect to a steering torque exceeding a predetermined value.

A power cylinder that generates a steering assist force is
It operates by the hydraulic pressure supplied from the hydraulic control valve, and as described above, the hydraulic pressure depends on the reduction of the throttle area in the throttle portion inside the hydraulic control valve. This is achieved by causing the throttle area of each throttle portion to have a region exhibiting a gradual decrease following the initial rapid decrease with respect to the relative angular displacement between the valve body and the valve body that occurs.

[0009] Such a mode of reduction is achieved by the valve body 1
This is realized by providing a notch 42 as shown in FIG. 7 at the corner of the land 22 on the valve body 2 side, which faces the corner of the land 10 on the side of the valve body 2 and forms the throttle portion 4 between the corner and the corner. I can do it. That is, in this case, the valve body 2 relatively moves (relative angular displacement) with respect to the valve body 1 from the neutral state shown in (a), and the side wall of the land 10 and the side wall of the land 22 move as shown in (b). The aperture area of the aperture portion 4 rapidly decreases until approaching the direction, but the aperture area of the aperture portion 4 is reduced by the corner on the land 10 side until the close state shown in FIG. The gap in the radial direction between the notch and the notch 42, in other words, depends on the variation of the cut depth of the notch 42, by making the notch 42 tapered as shown,
It shows a gradual decrease with respect to the relative movement.

Many inventions and ideas related to this type of hydraulic control valve have been made in the past, and various notch shapes have been proposed. However, it is easy to work and easy to manage the dimensions. Because of the superiority in processing, a notch 42 having a simple tapered shape as shown in FIG. 7 is generally employed.

[0011]

However, in the conventional hydraulic control valve constructed as described above, the transition to the gradually decreasing area of the throttle area at the position shown in FIG. When the amount of oil supplied to the oil supply chamber is large and the amount of oil passing through the throttle unit 4 is large, that is, during high-speed running when the driving speed of the hydraulic pump as the hydraulic pressure source is large, the steering assist force changes from a constant region to an increasing region. 6 is not smoothly performed, and FIG.
As shown by the broken line in the middle, there is a case where unstable characteristics are obtained in which a sudden increase at the end of a certain area is followed by a transition to a normal increase state, and a sudden change in the steering sensation during this transition causes the driver to feel uncomfortable. There were difficulties to give.

In order to solve this difficulty, Japanese Patent Application Laid-Open No. 57-198
Japanese Patent Publication No. 170 and Japanese Unexamined Patent Publication No. Sho 59-118577 each disclose a configuration having a tapered notch which changes the inclination angle in two steps at the corner of the land 22 on the valve element 2 side. However, this configuration has a problem in that the processing for forming the notch is complicated, and it is extremely difficult to realize a particularly small hydraulic control valve.

On the other hand, Japanese Utility Model Laid-Open No. 54-126340 discloses that
A part of the lands 10, 10... On the valve body 1 side is overlapped with the lands 22 on the valve body 2 facing each other, and the relative angular displacement between the valve body and the valve body exceeds a predetermined value. A configuration is disclosed in which the opening is started occasionally, and the above-mentioned unstable characteristics are eliminated by the synergistic action of these and the original throttle portion. However, in these configurations, in the neutral state, the large oil flow resistance in the overlap portion causes an increase in the load on the hydraulic pump as the hydraulic pressure source, and there is a disadvantage that the drive load of the hydraulic pump constantly increases.

[0014] The present invention has been made in view of such circumstances, and eliminates an unstable characteristic that occurs at an oil supply destination due to a sudden change in an area change state at a throttle portion with a simple configuration. It is an object of the present invention to provide a hydraulic control valve that does not cause an increase in the diameter of a valve body and a valve body and an increase in load on a hydraulic power source.

[0015]

A hydraulic control valve according to the present invention comprises a cylindrical valve body and a valve body which are coaxially and angularly displaced relative to each other, and are equally disposed on the inner periphery of the former and the outer periphery of the latter, respectively. Between each of the plurality of lands, an oil supply chamber connected to a hydraulic pressure source, oil supply chambers connected to different oil supply destinations on both sides thereof, and an oil supply chamber connected to an oil discharge destination on the other side. sequentially become in parallel, the aperture portion communicating said chambers are formed between the corners facing each of the lands, by a change of the aperture area that occurs with the relative angular displacement, into the feed oil destination In the hydraulic control valve for controlling the supply hydraulic pressure, among a plurality of lands on the valve body side or the valve body side, a pair or a plurality of pairs of lands located in radially opposed to each other are formed to have a width different from other lands.
And then underlap the squeezed area on both sides of these lands
Make the amount larger than the amount of
In addition, a notch portion is provided at a corner portion of each land including these lands so that a displacement angle at which the squeezed portion formed by each lands reaches a closed state is substantially the same.

[0016]

In [act present invention, the valve body in the periphery of the plurality of lands, or of a plurality of lands of the valve body outer periphery of to one or more pairs such pairs in the radial width of the land, these two sides
The amount of underlap in the throttle section of one
So as to be greater than-up amount, Oh Ru by varying the width of the other land. As a result, the throttle portions on both sides of the land whose width has been changed have the other throttle portions change from a sharply reduced area to a gradually reduced area in accordance with an increase in the relative angular displacement between the valve body and the valve body. Even when shifting , the rapid reduction area is maintained, and the sum of the throttle areas at all the throttle parts that determine the oil pressure supplied to the oil supply destination is:
Be a gradual transition from the sharp drop zone to the tapering zone in shows,
Accordingly, the unstable operation at the oil supply destination is eliminated.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings showing an embodiment thereof. FIG. 1 is a schematic cross-sectional view showing the configuration of the hydraulic control valve according to the present invention.

In the figure, reference numeral 1 denotes a valve body, and 2 denotes a valve body. On the inner peripheral surface of the cylindrical valve body 1, eight lands 10, 10 having a predetermined width equal to each other are separated from each other by eight grooves formed equally in the circumferential direction.
10 are provided equally spaced in the circumferential direction. Similarly, on the outer peripheral surface of the valve body 2 having an outer diameter substantially equal to the inner diameter of the valve body 1 and forming a thick cylindrical shape, similarly, six lands 21, 21. And a pair of lands 20, 20 having a narrower width than the lands 21, 21,... Are provided.

The valve body 1 and the valve body 2 are rotatably coaxially rotatably inserted with the latter inserted into the former, and the lands 10, 10... On the valve body 1 side and the lands 20, 20, 21 on the valve body 2 side. ,
Are positioned so as to be staggered in the circumferential direction, and are coaxially connected via a torsion bar 3 disposed on the axis of these shafts. Due to this connection, a relative angular displacement corresponding to the torsion of the torsion bar 3 occurs between the valve body 1 and the valve body 2, and the lands 10, 10. Circumferential surface and land 20, 20, 21,
Eight oil chambers surrounded by grooves between 21 ... and conversely, eight oil chambers surrounded by the circumferential surface of lands 20, 20, 21, 21 ... and the groove between lands 10, 10 ... As shown in the drawing, they are alternately arranged side by side at equal intervals in the circumferential direction. These oil chambers communicate with adjacent ones via a predetermined gap generated in the circumferential direction between the corner on the land 20 or the land 21 side and the corner on the land 10 facing the land. In addition, these gaps function as aperture portions that cause an area change as described later according to the relative angular displacement.

As shown in the figure, the land 2 which is narrower than the others
The two oil chambers formed outside 0, 20 and the two oil chambers outside the lands 21, 21,.
It is connected to the discharge side of a hydraulic pump P serving as a hydraulic pressure source through respective oil guide holes penetrating through the peripheral wall of the valve body 1,
The oil supply chambers 5, 5,... To which the hydraulic pressure generated by the hydraulic pump P is supplied.
Is composed. Also, the remaining lands 21, 21 ... outside 4
The two oil chambers are connected to an oil tank T serving as an oil discharge destination through respective oil drain holes penetrating the valve body 2 in the radial direction and a hollow portion inside the valve body 2, and are connected to the oil tank T. Are configured as oil discharge chambers 6, 6,.

On the other hand, of the eight oil chambers on the outer side of the lands 10, four adjacent to one side in the circumferential direction of the oil supply chambers 5, respectively, penetrate the peripheral wall of the valve body 1. via another oil guide hole, is connected to one of the cylinder chambers S _R of the power cylinder S is a hydraulic pressure of delivery destination, the cylinder chamber S _R
, For supplying hydraulic pressure to the oil supply chambers, and four adjacent to the other side of the oil supply chambers 5, 5,.
Are respectively connected to the other cylinder chamber S _L of the power cylinder S, constitute oil transfer chambers 8, 8 ... the for feeding hydraulic pressure to the cylinder chamber S _L.

FIG. 2 is a linear development view between the oil supply chambers 5, 5 outside the land 20 and the land 21 and the three oil discharge chambers 6, 6, 6 located on both sides of the land 20, respectively. With the above-described configuration, the oil passage extending from the oil supply chambers 7 and 7 to the oil discharge chambers 6 and 6 is provided on one side of the oil supply chambers 5 and 5 and the oil passage is provided on the other side through the oil supply chambers 8 and 8. There are oil passages to the oil chambers 6 and 6, respectively, and these oil passages include the land 20 or the land 21 as described above.
There is a throttle portion formed between the corner on the side and the corner on the side of the land 10 opposed thereto, and which changes the area according to the relative angular displacement between the valve body 1 and the valve body 2.

In the hydraulic control valve according to the present invention,
The radially opposite position on the outside of the valve body 2
Since the widths of the lands 20, 20 are narrower than the widths of the other lands 21, 21,...
Ridges 4a, 4a ... are larger than the other apertures 4b, 4b ...
It has a dur lap amount, and responds to the relative angular displacement.
The variation of the aperture area which is different from the others will be described. This aperture
4a, 4a are located on both sides of one of the two oil supply chambers 5, 5 shown in FIG. 2, and supply oil pressure supplied from the hydraulic pump P to the oil supply chamber 5 on both sides. Distributed to rooms 7 and 8,
The cylinder chamber S communicating with the oil supply chambers 7 and 8 respectively.
_R and S _L have the function of controlling the oil pressure supplied to them, and the other oil supply chamber 5 has an aperture smaller than the throttle portions 4a and 4a.
The squeezed portions 4b, 4b having the amount of underlap perform the same function. Further, throttle portions 4b, 4b,... Are formed on both sides of each of the three oil discharge chambers 6, 6, 6 shown in the figure.

The lands forming the narrow portions 4a, 4a in this manner
At each of the corners 20, 20, tapered notches 40, 40 are formed by diagonally notching them, and
Each of the corners of the lands 21 forming the b, 4b is provided with a notch 41, 41, which is similarly formed. These notches 40 and 41 have a circumferential length L (a straight line distance in FIG. 2) between the intersection of the land 20 or the land 21 and the corner of the land 10 facing each other. ) Are formed to be the same as shown.

For these notches 40 and 41, a large-diameter rotary grindstone having a rotary axis parallel to the axis of the valve body 2 is used. By giving a predetermined feed in a direction approaching the axis of the body 2, it can be formed collectively between the lands 20 and 21 adjacent to each other. The difference is apparently due to the difference in the width between the lands 20 and 21 where these are formed respectively.
This is only caused by the difference in the cutting depth of the holes. That is, these notches 40 and 41 allow the valve body 2 to be set at 45 °.
The valve element 2 is rotated eight times, and a predetermined feed is applied to the above-mentioned rotating grindstone at each rotation position.
The outer periphery of the land 20, 21, ... can be formed for all, this form
To achieve this, each of the corners of the land of the same width lined up on the outer circumference of the valve
In the conventional hydraulic control valve that forms the same notch
Only the same number of processing steps as in the case is required.

FIG. 2 shows a neutral state in which there is no relative angular displacement between the valve body 1 and the valve body 2. In this case, the throttle portions 4a, 4a on both sides of one oil supply chamber 5 are in an open state having the same throttle area, and the throttle portions 4b, 4b on both sides of the other oil supply chamber 5 and the oil drain chambers 6, 6, 6. 4b are also in an open state having the same throttle area, the hydraulic pressure supplied from the hydraulic pump P to the oil supply chambers 5, 5 passes through the throttle portions 4a, 4a or 4b, 4b on both sides thereof, respectively. Are equally distributed to the oil supply chambers 7 and 8 on both sides of the valve body 2 and then flow into the oil discharge chamber 6 through the throttle portions 4b and 4b on the other side, and further return to the oil tank T through the hollow portion of the valve body 2.

[0027] Thus this time, both the cylinder chambers S _R of the oil transfer chamber 7, 8 and between the power cylinder S connected thereto, respectively, the pressure difference between the S _L is not generated, the power cylinder S is in any No force is generated. Further, at this time, since there is no portion that generates a large flow resistance in the oil passage from the hydraulic pump P to the oil tank T, the driving load of the hydraulic pump P is kept small.

On the other hand, when the valve body 2 rotates clockwise relative to the valve body 1 in FIG.
The throttle area of the throttle portion 4a or the throttle portion 4b between the oil transfer chambers 5 and 7 is reduced, and the oil transfer chambers 7, 7 and the oil discharge chambers 6, 6 are reduced.
6 and the aperture area of the aperture portions 4b, 4b increases,
The constriction area of the constricted portion 4a or the constricted portion 4b between the oil supply chambers 5, 5 and the oil supply chambers 8, 8 is increased on the contrary.
The throttle areas of the throttle portions 4b, 4b between the oil discharge chambers 8 and the oil discharge chambers 6, 6 are reduced. This state is linearly developed as in FIG. 2 and is shown in FIG.

When the displacement angle further increases from this state,
The above-described change in the aperture area in each of the aperture sections 4a, 4b,... Is promoted, and the aperture sections 4a, 4b,.
Due to the action of the notches 40, 41 formed in the above-described manner at the corners of the lands 20, 21, the closed state of each of the throttles 4a, 4b,. The amount of displacement occurs simultaneously at the obtained displacement angle. This state is linearly developed as in FIGS. 2 and 3 and is shown in FIG. FIG. 3
4 and the white arrows in FIG. 4 indicate the moving direction of the valve body 2 with respect to the valve body 1.

From the state of FIG. 2 to the state of FIG. 4 through the state of FIG. 3, most of the oil supplied to the oil supply chambers 5, 5 passes through one of the throttle portions 4a and 4b whose throttle area is increased. Oil transfer chamber 8,
8, the remaining part leaks out to the oil feed chambers 7, 7 through the other throttle portions 4a, 4b whose throttle areas are reduced. At this time, while the internal pressure of the oil supply chamber 8 is kept substantially equal to that of the oil supply chamber 5,
The internal pressure of the oil transfer chamber 7 is reduced by the reduced pressure associated with the flow of the throttle portions 4a and 4b having a reduced throttle area, and is reduced between the oil transfer chambers 7 and 8 and the cylinder chambers S _R , Between S _L
The pressure difference corresponding to decompression component occurs, the power cylinder S by this pressure difference, to generate a hydraulic force directed to the S _R from the cylinder chamber S _L.

Further, with the operation of the power cylinder S, enclosed oil in the cylinder chamber S _R is pushed out, it is a leakage oil from the oil supply chamber 5,5 by refluxing the Okuaburashitsu 7,7 They merge and flow into the oil discharge chamber 6 via the throttle portions 4b, 4b whose throttle areas are increased on the other side of the oil feed chambers 7, 7.
The oil discharge chamber 6 also leaks oil from the oil feed chambers 8, 8 through the throttle portions 4 b, 4 b in a state where the throttle area is reduced. , 7 and is discharged to an oil tank T maintained at a low pressure state through a hollow portion inside the valve body 2.

That is, the pressure difference generated between the oil supply chambers 8, 8 and the oil supply chambers 7, 7 and available in the power cylinder S is:
Restriction section to reduce the area between oil supply chambers 5,5 and oil supply chambers 7,7
4a, 4b, and throttle portions 4b, 4b, which are also reduced in area between the oil feed chambers 8, 8 and the oil drain chambers 6, 6, that is, formed on the periphery of the valve body 1 and the valve body 2. Restrictor 4a, 4b
... Depending on the degree of reduction of the throttle area that occurs as a whole, the throttle area decreases with an increase in the displacement angle between the valve body 1 and the valve body 2. The valve body 1
The displacement angle generated between the torsion bar 3 and the valve body 2 corresponds to the magnitude of the force applied to cause torsion in the torsion bar 3 connecting the two, and therefore, the steering applied to the steering wheel on the torsion bar 3 When the torque is applied, a steering assist force corresponding to the magnitude of the torque is obtained in the direction of the steering torque applied to the steering wheel by the hydraulic pressure generated by the power cylinder S.

Now, with an increase in the relative angular displacement between the valve body 1 and the valve body 2, the side wall of the land 10 and the land 20 or 21
Until the side wall of the diaphragm approaches in the circumferential direction,
The throttle areas 4a and 4b show a sharp decrease as the displacement angle between the valve body 1 and the valve body 2 increases, and thereafter, the throttle sections 4a and 4b until the closed state is reached. The width of the radial gap between the notches 40 and 41 formed at the corners on the lands 20 and 21 and the corners on the land 10 facing the same, in other words, the notch Notch
Since the notches 40 and 41 are tapered as described above, the area of the apertures of the apertures 4a and 4b is increased by increasing the displacement angle. And gradually decreases. That is, the throttle unit 4
In the aspect of the reduction of the drawing area in a and 4b, a transition is made from a sharply reduced area to a gradually reduced area at a position where the side wall of the land 10 and the side wall of the land 20 or 21 are close to each other in the circumferential direction.

FIG. 3 shows a state where the side walls on both sides of the lands 21, 21 and the corresponding side walls of the lands 10, 10,... Are aligned in the circumferential direction, that is, the narrowed portions 4b, 4b. However, as described above, the pair of lands 20, 20 at the positions opposed to each other in the radial direction of the valve body 2 has a narrower width than the lands 21, 21,. A predetermined gap δ remains in the circumferential direction between the land 20 and the corresponding side wall of the land 10 even in the state shown in FIG.
The narrowed area of the narrowed portion 4a is within a sharply reduced area depending on the reduction of the gap δ. That is, in the range of the relative angular displacement from the state shown in FIG. 3 to the time when the gap δ becomes zero, the squeezing area at the squeezing portions 4b, 4b.
The state in which the rapid reduction of the drawing area in a and 4a is mixed.

FIG. 5 shows two throttle portions 4a, 4a and six throttle portions 4b, 4b, which simultaneously reduce the throttle area on the circumference of the valve body 2.
4B is a graph showing an area change state in 4b. As described above, the transition point from the rapidly decreasing region to the gradually decreasing region in the narrowing portions 4a, 4a is as follows.
Since the displacement angle is shifted to the side where the displacement angle is larger than the transition point at the throttle portions 4b, 4b, the sudden decrease between the two transition points occurs during the reduction of the throttle area of the entire hydraulic control valve indicated by the solid line in the drawing. An intermediate region having an average reduction rate between the region and the gradually decreasing region appears, and the transition from the rapid decreasing region to the gradually decreasing region is performed slowly. By this gentle transition, the transition of the steering assist force from the constant region to the increasing region is surely performed, and there is little possibility that the unstable characteristic shown by the broken line in FIG. 6 occurs.

In the above description of the operation, the case where the relative angular displacement of the valve body 2 with respect to the valve body 1 occurs clockwise in FIG. 1, but the same applies to the counterclockwise relative angular displacement. Needless to say, the above operation is performed.

In this embodiment, the pair of lands 20, 20 inside the refueling chambers 5, 5 is narrower than the other lands 21, 21,. A pair of lands, a pair of lands on the inner side of the oil drainage chambers 6, 6, a pair of lands on the inner side, lands 10, 10,... Any land may have a different width than the other lands.

The notches 40, 41 formed to match the cut-off positions of the throttles 4a, 4b are not limited to those shown in this embodiment, but may have other shapes. These notches 40, 41 are not limited to the valve body 2 side, but may be formed at the corners of the lands 10, 10,... On the valve body 1 side.

[0039]

As described in detail above, in the hydraulic control valve according to the present invention, the width of one or a plurality of pairs of lands on the valve body side or the valve body side located in the radially opposed position is made equal to the width of the other lands. Both sides of the land with different widths
The amount of underlap in the throttle section of one
Land with larger width than width
A simple configuration in which notches are provided at the corners of each land including these so that the throttles formed by these are closed at substantially the same displacement angle, the entire throttles of the valve body and the valve body are provided. In this case, the transition from the rapid reduction area to the gradual reduction area of the throttle area can be made gradual, and the unstable characteristic generated at the oil supply destination at this transition is effectively eliminated. The risk of giving the driver a sense of discomfort due to a sudden change in sense is reduced. Also it is not necessary to form the notch portion with a complicated shape, it is possible to diameter of the valve body and the valve body, further, each of the diaphragm portions A
The present invention has an excellent effect, for example, since it has an under wrap and there is no throttle portion which is always in a closed state, so that a steady load on a hydraulic power source can be kept low.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view of a hydraulic control valve according to the present invention.

FIG. 2 is an operation explanatory view showing the hydraulic control valve according to the present invention linearly developed.

FIG. 3 is an operation explanatory view showing the hydraulic control valve according to the present invention linearly developed.

FIG. 4 is an operation explanatory view showing the hydraulic control valve according to the present invention linearly developed.

FIG. 5 is a graph showing a change state of a throttle area of the hydraulic control valve according to the present invention.

FIG. 6 is an explanatory diagram of general characteristics and unstable characteristics of the power steering device.

FIG. 7 is an operation explanatory view of a conventional hydraulic control valve.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Valve body 2 Valve body 4a Throttle part 4b Throttle part 5 Oil supply chamber 6 Drainage chamber 7 Oil supply chamber 8 Land transfer chamber 10 Land 20 Land 21 Land 40 Notch 41 Notch P Hydraulic pump S Power cylinder T Oil tank

Claims (1)

(57) [Scope of request for utility model registration] 1. A hydraulic valve, comprising: a cylindrical valve body and a valve body which are coaxially displaced in relative angle, and are connected to a hydraulic pressure source between a plurality of lands respectively arranged on an inner periphery of the former and an outer periphery of the latter. The oil supply chamber, the oil supply chambers connected to different oil supply destinations on both sides of the oil supply chamber, and the oil supply chambers connected to the oil discharge destination on the other side are sequentially arranged.
It was following parallel, the aperture portion communicating said chambers are formed between the corners facing each of the lands, by a change of the aperture area that occurs with the relative angular displacement, to the feed oil destination In the hydraulic control valve for controlling the supply hydraulic pressure, of the plurality of lands on the valve body side or the valve body side, a pair or a plurality of pairs of lands that are located radially opposite to each other are formed to have a width different from the others. Of the restriction on both sides of these lands
Set the amount of Darlap more than the amount of
Yes Increase, hydraulic control valve, characterized in that the corners of the lands containing these lands comprises a notch for a displacement angle to the state deadline the narrowed portion which respectively form substantially the same .