JPH057573U - Hydraulic control valve - Google Patents

Abstract

(57) [Abstract] [Purpose] The instability characteristic that occurs at the oil destination due to a sudden change in the area change state at the throttle between the valve body and the valve body is used to increase the diameter of the valve body and the valve body. In addition, it is solved with a simple configuration without increasing the load on the hydraulic power source. [Structure] Of the lands that are evenly arranged on the outer periphery of the valve body 2 that rotates relative to the valve body 1 coaxially, the width of a pair (or a plurality of pairs) of lands 20 that are opposed to each other in the radial direction is ,
Make it different from the width of the other lands 21, 21 ... Further, due to the relative angular displacement between the valve body 1 and the valve body 2, the throttle portions 4a, 4a on both sides of the lands 20, 20 and the lands 21, 21 ... throttle portions 4b on both sides,
Notches are provided at the corners on both sides of each of the lands 20, 21 ... so that the displacement angles of 4b ...

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a hydraulic control valve that controls hydraulic pressures to be fed to two different destinations in accordance with the relative angular displacement between a valve body and a valve body that occur on the same axis, and particularly to a hydraulic power steering. The present invention relates to a hydraulic control valve that is used to control a hydraulic pressure supplied to a power cylinder that generates a steering assist force according to a steering wheel operation in a take-off device.

[0002]

[Prior Art]

 The hydraulic power steering system assists steering by hydraulic pressure generated by a double-acting hydraulic cylinder (power cylinder) arranged in the steering mechanism, and reduces the labor load required to operate the steering wheel of a vehicle. The aim is to reduce the amount of the vehicle to obtain a light steering feel. In recent years, it has been widely used not only for large vehicles such as trucks and buses but also for small vehicles such as ordinary passenger cars.

This power steering apparatus includes a hydraulic pump (hydraulic power source) driven by an engine and an oil tank (drainage destination) for storing hydraulic oil, and both cylinder chambers (destination destination) of the power cylinder. Between them, a hydraulic control valve that controls the supply and discharge of hydraulic pressure according to the direction and magnitude of the steering torque applied to the steering wheel is provided. As this hydraulic control valve, a rotary hydraulic control valve that directly utilizes the rotation of the steering wheel is generally used, and it has an input shaft connected to the steering wheel and an output shaft connected to the steering mechanism. A valve body, which is connected coaxially via a torsion bar and is integrally formed at one connecting end, is coaxially rotatable relative to a cylindrical valve body engaged with the other connecting end. When the steering wheel is fitted and a steering torque is applied to the steered wheels, a relative angular displacement is generated between the valve body and the valve body as the torsion bar is twisted.

The valve body and the valve body are positioned so that a plurality of lands, which are equally arranged on the inner circumference of the former and the outer circumference of the latter, are arranged in a staggered manner in the circumferential direction. It is located between the oil supply chamber and the oil discharge chamber, which are in communication with the oil pressure source and the oil discharge destination, and between the oil discharge chambers on both sides of the oil supply chamber. A pair of oil feed chambers that communicate with each other are provided side by side. Each of these chambers communicates with each other through narrowed portions formed between the corner portions of the lands facing each other on both sides. The hydraulic pressure to be sent to the destination is controlled.

That is, when there is no relative angular displacement between the valve body and the valve body, the hydraulic pressure supplied to the oil supply chamber is evenly distributed to the pair of oil supply chambers via the throttles on both sides of the oil supply chamber. Then, the oil is introduced into the oil discharge chamber through the throttle on the other side of each oil feed chamber and is returned to the oil tank, whereas a relative angular displacement occurs between the valve body and the valve body, and When the throttle area of the throttle portion is different, the oil pressure supplied to the oil supply chamber is mainly introduced into one oil feed chamber through the throttle portion on one side (the side where the throttle area is increased), and the oil feed chamber and the other A pressure difference is generated between the power supply chamber and the oil supply chamber of the power cylinder, and between the cylinder chambers of the power cylinders communicating with the respective oil supply chambers, and the power cylinder generates an oil pressure corresponding to this pressure difference.

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) on the other side of the oil supply chamber, and the degree of decrease is the magnitude of the relative angular displacement. Immediately, since it corresponds to the magnitude of the steering torque applied to the steering wheel, the hydraulic pressure generated by the power cylinder provides a steering assist force corresponding to the magnitude of the steering torque in the operating direction of the steering wheel. Note that the oil pushed out from the other cylinder chamber due to 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 is provided on one side of the oil feed chamber. After that, a part of the oil introduced from the oil supply chamber into one of the oil supply chambers adjacent to each other and further introduced into the one oil supply chamber is also subjected to a reflux throttle having a reduced throttle area on the other side of the oil supply chamber. After that, they are introduced into the adjacent oil drain chambers, and both of them are discharged into the oil tank.

Now, in a power steering apparatus that obtains a steering assist force according to the operation of such a hydraulic control valve, a general increasing characteristic of the steering assist force with an increase in steering torque applied to a steering wheel is as follows. As shown in FIG. 6, the steering torque has a constant region in which a small steering assist force is obtained in a small range, and the steering assist force increases to a steering torque exceeding a predetermined value. It is a characteristic to do.

The power cylinder that generates the steering assist force is operated by the feed hydraulic pressure from the hydraulic control valve, and as described above, the feed hydraulic pressure depends on the reduction mode of the throttle area in the throttle portion inside the hydraulic control valve. From the above, the characteristics described above show a gradual decrease in the throttle area of each throttle part following the initial sharp decrease with respect to the relative angular displacement between the valve body and the valve element that occurs with the addition of steering torque. This is achieved by making the area occur.

Such a reduction mode is shown in the drawing in which the corner portion of the land 22 on the valve body 1 side faces the corner portion of the land 22 on the valve body 2 side that forms the narrowed portion 4 with the corner portion. It can be realized by providing a notch 42 as shown in FIG. That is, in this case, the valve body 2 moves relative to the valve body 1 (relative angular displacement) from the neutral state shown in (a), and as shown in (b), the side wall of the land 10 and the side wall of the land 22 are separated from each other. The throttle area of the throttle portion 4 decreases sharply until it approaches in the circumferential direction, but the throttle area of the throttle portion 4 becomes smaller than the land area until it reaches the deadline state shown in (c) by further relative movement. Depending on the radial gap between the corner on the 10 side and the notch 42, in other words, how the depth of cut of the notch 42 changes, the notch 42 is tapered as shown in the figure. By doing so, a gradual decrease is exhibited with respect to the relative movement.

Many inventions and devices relating to this type of hydraulic control valve have been made in the past, and various cutout shapes have been proposed, but they are easy to process, and dimensional control is easy. Because of its superiority in processing, a notch 42 having a simple taper shape as shown in FIG. 7 is generally adopted.

[0011]

[Problems to be solved by the device]

 However, in the conventional hydraulic control valve configured as described above, the throttle area at the position shown in FIG. When the amount of oil is large and the amount of oil passing through the throttle 4 is large, that is, when the hydraulic pump that is the hydraulic power source has a high driving speed, the steering assist force smoothly transitions from a constant range to an increased range during high-speed traveling. However, as shown by the broken line in FIG. 6, an unstable characteristic may be obtained in which a sudden increase occurs at the end of a certain region and then a normal increase state is obtained. There was a difficulty in giving the driver a feeling of strangeness.

In order to solve this difficulty, in Japanese Patent Laid-Open No. 57-198170 and Japanese Patent Laid-Open No. 59-118577, the tilt angle is changed in two steps at the corner of the land 22 on the valve body 2 side. Although each configuration with a tapered notch is disclosed, in this configuration, the processing for forming the notch becomes complicated, and it is extremely difficult to realize it especially with a small hydraulic control valve. There is a problem.

On the other hand, in Japanese Utility Model Laid-Open No. 54-126340, a part of the lands 10, 10 on the valve body 1 side is overlapped with the lands 22 on the valve body 2 side facing each other. When the relative angular displacement between the valve body and the valve body exceeds a specified value, opening is started, and the synergistic action of these and the original throttle part eliminates the unstable characteristics described above. Is disclosed. However, in these configurations, in the neutral state, the large oil passage resistance in the overlap portion causes an increase in the load of the hydraulic pump, which is the hydraulic source, and the drive load of the hydraulic pump constantly increases. is there.

The present invention has been made in view of such circumstances, and eliminates the unstable characteristic generated at the oil destination due to the sudden change of the area change state in the throttle portion with a simple configuration, An object of the present invention is to provide a hydraulic control valve that does not increase the diameters of the valve body and the valve body and increase the load on the hydraulic source.

[0015]

[Means for Solving the Problems]

 A hydraulic control valve according to the present invention comprises a cylindrical valve body and a valve body that are coaxially displaced relative to each other, and between a plurality of lands equally arranged on the inner circumference of the former and the outer circumference of the latter, respectively. The oil supply chamber connected to the oil pressure source, the oil supply chambers connected to different oil destinations on both sides of the oil supply chamber, and the oil discharge chambers connected to the oil discharge destinations on the other side of the oil supply chambers are arranged in parallel. The hydraulic control for controlling the hydraulic pressure to be fed to the destination by the change of the throttle area caused by the relative angular displacement in the throttle portion formed between the opposite corner portions and communicating the chambers. In the valve, among the lands on the valve body side or the valve body side, a pair or a plurality of pairs of lands that are radially opposed to each other have a width different from other lands. At the corners of each land, including the Characterized by comprising a notch for an angle substantially the same.

[0016]

[Action]

 In the present invention, of the lands on the inner circumference of the valve body or the lands on the outer circumference of the valve body, the width of a pair or a pair of lands forming a pair in the radial direction is different from the width of the other lands. The throttles formed between the corners on both sides of these lands and the corners of the lands facing each other are different from each other depending on the increase of the relative angular displacement between the valve body and the valve body. When the throttle section shifts from the sharp reduction area of the throttle area to the gradual reduction area, it is still in the sharp reduction area or is already in the gradual reduction area, and all the throttle sections that determine the hydraulic pressure to be fed to the oil destination The total throttle area shows a gradual transition from the sudden decrease region to the gradual decrease region, and with this, the unstable operation at the oil destination is eliminated.

[0017]

【Example】

 Hereinafter, the present invention will be described in detail with reference to the drawings showing an embodiment thereof. FIG. 1 is a schematic cross-sectional view showing the structure of a hydraulic control valve according to the present invention.

In the figure, 1 is a valve body and 2 is a valve body. On the inner peripheral surface of the cylindrical valve body 1, there are eight lands 10, 10 ... Which are separated from each other by eight grooves formed equidistantly in the circumferential direction and have a predetermined width. , Are evenly arranged in the circumferential direction. Further, the outer diameter surface of the valve body 2 having a thick cylindrical shape, which has an outer diameter substantially equal to the inner diameter of the valve body 1, has six lands 21, 21 ... , And a pair of lands 20, 20 having a width narrower than the lands 21, 21 ...

The valve body 1 and the valve body 2 have the latter inserted in the former so as to be relatively rotatable on the same axis, and the lands 10, 10 ... On the valve body 1 side and the lands 20, 20, on the valve body 2 side. 21 and 21 are positioned so as to be arranged in a staggered manner in the circumferential direction, and are coaxially connected to each other via a torsion bar 3 arranged on the axial center of these. Due to this connection, a relative angular displacement occurs between the valve body 1 and the valve body 2 according to the torsion of the torsion bar 3, and between the valve body 1 and the valve body 2, lands 10, 10, ... Eight oil chambers surrounded by the circumferential surface of the land and the groove portion between the lands 20, 20, 21, 21 ..., and conversely, the groove portion between the circumferential surface of the lands 20, 20, 21, 21 ,. Eight oil chambers surrounded by and are alternately arranged in parallel in the circumferential direction as shown in the figure. These oil chambers communicate with adjacent ones via a predetermined circumferential gap formed between the corner portion of the land 20 or the land 21 side and the corner portion of the land 10 side facing the land 20 or land 21 side. Therefore, these gaps function as a diaphragm portion that causes an area change as described later according to the relative angular displacement.

As shown in the drawing, the two oil chambers formed outside the lands 20, 20 having a narrower width than the other, and the lands 21, 21 ... The oil supply chambers 5, 5 are connected to the discharge side of a hydraulic pump P, which is a hydraulic pressure source, through respective oil guide holes that penetrate the peripheral wall of the valve body 1, and the generated hydraulic pressure of the hydraulic pump P is supplied to the hydraulic supply chambers 5, 5. Is composed of. The remaining four lands 21, 21 ... Outer four oil chambers are the oil to be drained through the respective oil drain holes penetrating the valve body 2 in the radial direction and the hollow portions inside the valve body 2. Are connected to the tank T and constitute oil drainage chambers 6, 6 ... Which serve as passages for oil discharged to the oil tank T.

On the other hand, among the eight oil chambers on the outside of the lands 10, 10, ..., four adjacent to each other on one side in the circumferential direction of the oil supply chambers 5, 5 ... penetrate the peripheral wall of the valve body 1. The oil feed chambers 7, 7 are connected to one cylinder chamber S _R of the power cylinder S, which is the destination of the hydraulic pressure, through the respective oil guide holes, and feed the hydraulic pressure to the cylinder chamber S _R. ... Ri configured to your, also four to each Neighboring the oil transfer chamber 5,5 ... the other side of the is respectively connected to the other cylinder chamber S _L of the power cylinder S, the cylinder chamber S _L Are configured to supply oil pressure to the oil supply chambers 8, 8, ....

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 oil supply chambers 5, 5, respectively. .. With the configuration described above, the oil passages through the oil supply chambers 7, 7 to the oil discharge chambers 6, 6 are provided on one side of the oil supply chambers 5, 5 and the oil passages through the oil supply chambers 8, 8 are provided on the other side. There are oil passages to the oil chambers 6 and 6, respectively, and these oil passages, as described above, include the corner portion on the side of the land 20 or 21 and the opposite corner portion on the side of the land 10 respectively. There is a throttle portion that is formed between the valve body 1 and the valve body 2 and causes an area change in accordance with the diagonal displacement.

In the hydraulic control valve according to the present invention, since the width of the land 20 is narrower than the width of the other lands 21, 21, ... The manner of changing the aperture area different from the aperture portions 4b and 4b of Fig. 4 is shown. The throttle portions 4a, 4a are located on both sides of one of the two oil supply chambers 5, 5 shown in the figure, and the hydraulic pressure supplied from the hydraulic pump P to the oil supply chamber 5 is supplied to both sides. allocated to the oil chamber 7,8, the cylinder chamber S _R for each communicating with these oil transfer chambers 7 and 8, serve to control the delivery pressure of the S _L, in the other feed chamber 5, the diaphragm The parts 4b and 4b perform the same function. Further, throttle parts 4b, 4b ... Are formed on both sides of each of the three illustrated oil drain chambers 6, 6, 6.

As described above, at each corner of the lands 20, 20 forming the narrowed portions 4a, 4a, there are taper notched portions 40, 40 as shown in the drawing, which are formed by obliquely cutting the land. Similarly formed notch portions 41, 41 ... Are provided at the respective corners of the lands 21, 21 ... Forming the portions 4b, 4b. These notches 40 and 41 have a circumferential length L (a linear 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 in the figure.

The notches 40 and 41 are made of a large-diameter rotary grindstone having a rotation axis that is parallel to the axis of the valve body 2, and the valve is used in a plane including both axes. It can be collectively formed between the adjacent lands 20 and 21 by giving a predetermined feed in the direction of approaching the axis of the body 2, and the shape between the notches 40 and 41 as shown in the figure. The difference between the two is caused only by the difference in the cutting depth due to the difference in the width between the lands 20 and 21 formed respectively. That is, these notches 40 and 41 rotate the valve body 2 by 45 °, and at each rotation position, the land on the outer periphery of the valve body 2 is repeated by repeating the machining eight times to apply the predetermined feed to the above-mentioned rotary grindstone. It can be formed for all of 20, 21 ..., and the processing man-hours for this are small.

FIG. 2 shows a neutral state in which relative angular displacement is not generated between the valve body 1 and the valve body 2. In this case, the throttle portions 4a, 4a on both sides of the one oil supply chamber 5 are in an open state having throttle areas that are equal to each other, and the other oil supply chamber 5 and the throttle portions on both sides of the oil discharge chambers 6, 6 and 6 are open. Since the parts 4b, 4b ... Are also in the open state having mutually equal throttle areas, the hydraulic pressure supplied from the hydraulic pump P to the oil supply chambers 5, 5 is the throttle parts 4a, 4a or 4b, 4b on both sides thereof. After that, the oil is evenly distributed to the oil supply chambers 7 and 8 on both sides, then flows into the oil discharge chamber 6 through the throttle portions 4b and 4b on the other side, and further passes through the hollow portion of the valve body 2 to the oil tank T 2. Bring to reflux.

Therefore, at this time, no pressure difference is generated between the oil feed chambers 7 and 8 and between both cylinder chambers S _R and S _{L of the} power cylinder S connected to the respective oil supply chambers 7 and 8, and the power cylinder S does not have any difference. No power is generated. Further, at this time, since there is no portion in the oil passage from the hydraulic pump P to the oil tank T that generates a large flow resistance, the driving load of the hydraulic pump P is kept small.

On the other hand, when the valve body 2 is rotated relative to the valve body 1 in the clockwise direction in FIG. 1, the throttle portion 4 a or the throttle portion 4 b between the oil supply chambers 5, 5 and the oil supply chambers 7, 7 is closed. Area of the oil supply chambers 7, 7 and the oil discharge chambers 6, 6 is increased, and the area of the throttles 4b, 4b between the oil supply chambers 7, 7 and the oil discharge chambers 6, 6 is increased. On the contrary, the throttle area of the throttle portion 4a or the throttle portion 4b between the oil supply chambers 8 and 8 is increased, and the throttle portions 4b and 4b between the oil supply chambers 8 and 8 and the oil discharge chambers 6 and 6 are increased. The throttle area is reduced. This state is linearly expanded as in FIG. 2 and shown in FIG.

When the displacement angle is further increased from this state, the above-mentioned change of the diaphragm area in each of the diaphragm portions 4a, 4b ... Is promoted, and the diaphragm portions 4a, 4b .. The throttle opening reaches zero, that is, the deadline is reached. The shut-off state of each throttle portion 4a, 4b ... is L on the circumference of the valve body 2 due to the action of the notch portions 40, 41 formed in the above-described manner at the corner portions of each land 20, 21. It occurs simultaneously at the displacement angle at which the displacement amount is obtained. This state is linearly expanded in the same manner as in FIGS. 2 and 3 and is shown in FIG. The white arrow in FIGS. 3 and 4 indicates the moving direction of the valve body 2 with respect to the valve body 1.

From the state shown in FIG. 2 through the state shown in FIG. 3 to the state shown in FIG. 4, most of the oil supplied to the oil supply chambers 5, 5 is the one throttle portion 4a, 4b whose throttle area has been increased. After that, it flows into the oil feed chambers 8 and 8 and the remaining part leaks out to the oil feed chambers 7 and 7 via the other throttle portions 4a and 4b whose throttle area is reduced. At this time, the internal pressure of the oil feed chamber 8 is kept substantially equal to that of the oil feed chamber 5, whereas the internal pressure of the oil feed chamber 7 is equal to the reduced pressure due to the flow of the throttle portions 4a, 4b with the reduced throttle area. As a result, a pressure difference corresponding to the reduced pressure is generated between the oil feed chambers 7 and 8 and between the cylinder chambers S _R and S _L communicating with the oil supply chambers 7 and 8, respectively. , Generates hydraulic pressure from the cylinder chamber S _L to S _R.

Further, with the operation of the power cylinder S, the filled oil in the cylinder chamber S _R is pushed out, and this is returned to the oil feed chambers 7, 7 and leaks out from the oil feed chambers 5, 5. It merges with the oil and flows into the oil discharge chamber 6 via the throttle portions 4b, 4b in the state where the throttle area is increased on the other side of the oil supply chambers 7, 7. The oil discharge chamber 6 also leaks oil through the throttle portions 4b and 4b in a state where the throttle area is reduced from the oil feed chambers 8 and 8. , 7 and then merge with the inflowing oil from the valve body 2 and pass through the hollow portion inside the valve body 2 to be discharged to the oil tank T maintained at a low pressure.

That is, the pressure difference that occurs between the oil feed chambers 8 and 8 and the oil feed chambers 7 and 7 and can be used in the power cylinder S is the same as the oil feed chambers 5 and 5 and the oil feed chambers 7 and 7. In the throttle portions 4a, 4b that reduce the area between them, and in the throttle portions 4b, 4b that also reduce the area between the oil feed chambers 8, 8 and the oil discharge chambers 6, 6, that is, the valve body 1 and the valve body. The throttle areas 4a, 4b formed on the circumference of 2 depend on the degree of reduction of the throttle area that occurs in the whole, and this throttle area decreases as the displacement angle between the valve body 1 and the valve body 2 increases. To do. Since the displacement angle generated between the valve body 1 and the valve body 2 corresponds to the magnitude of the force applied to cause torsion in the torsion bar 3 connecting them, the steering bar (steering wheel) When a steering torque applied to the wheel is applied, the hydraulic pressure generated by the power cylinder S provides a steering assist force corresponding to the magnitude of the torque in the direction of the steering torque applied to the steered wheels.

By the way, as the relative angular displacement between the valve body 1 and the valve body 2 increases, until the side wall of the land 10 and the side wall of the land 20 or 21 come close to each other in the circumferential direction, the throttle portion is The throttle areas of 4a and 4b show a sharp decrease as the displacement angle between the valve body 1 and the valve body 2 increases. , 4b, the width of the radial gap between the notches 40 and 41 formed in the corners on the lands 20 and 21 side and the corners on the land 10 side facing the notches 40 and 41, in other words, The notch portions 40 and 41 are dependent on the variation of the depth, and the notch portions 40 and 41 have the tapered shape as described above. Therefore, the throttle areas of the throttle portions 4a and 4b have the above-mentioned displacements. As the angle increases, it gradually decreases. That is, the manner of reducing the throttle area in the throttle portions 4a and 4b shifts from the sudden decrease zone to the gradually decreasing zone at the 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 that the side walls on both sides of the lands 21, 21 ... And the side walls of the corresponding 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 located at positions opposite to each other in the radial direction of the valve body 2 have a width narrower than that of the lands 21, 21 ,. Therefore, 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. 3, and the throttle area of the throttle portion 4a is equal to this gap δ. It is in the area of sharp decline that depends on the decrease in That is, within the range of relative angular displacement from the state shown in FIG. 3 until the gap δ becomes zero, the squeezing area of the squeezing portions 4b, 4b ... In this state, there is a mixture of the sharp reduction of the drawing area at.

FIG. 5 is a graph showing the area change state in the two throttle portions 4a, 4a and the six throttle portions 4b, 4b ... Which simultaneously reduce the throttle area on the circumference of the valve body 2. .. As described above, the transition point from the sharp reduction region to the gradual reduction region in the throttle portions 4a, 4a is shifted to the side where the displacement angle is larger than the transition point in the throttle portions 4b, 4b .. In the mode of reduction of the throttle area of the entire hydraulic control valve shown, an intermediate region with an average reduction rate between the sudden decrease region and the gradually decreasing region appears between both transition points, and the transition from the sudden decreasing region to the gradually decreasing region occurs. Is done slowly. This gradual transition results in reliable transition of the steering assist force from the constant region to the increase region, and there is little possibility that the unstable characteristic shown by the broken line in FIG. 6 will occur.

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 in the clockwise direction in FIG. 1 has been described, but the relative angular displacement in the counterclockwise direction does not occur at all. It goes without saying that the same operation is performed.

In the present embodiment, the pair of lands 20, 20 inside the fuel supply chambers 5, 5 are made narrower than the other lands 21, 21, ... Two pairs of lands, one pair or two pairs of lands inside the oil drainage chambers 6, 6 ... Lands 10 on the side of the valve body 1 ... , The width of any land may be different from other lands.

Further, the notches 40 and 41 formed to match the deadline positions of the narrowed portions 4a and 4b are not limited to the shapes shown in this embodiment, and may have other shapes. The notches 40 and 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]

[Effect of the device]

 As described above in detail, in the hydraulic control valve according to the present invention, the width of the valve body side or the pair of lands on the valve body side or the plurality of pairs of lands at the positions facing each other in the radial direction is made different from the widths of other lands, and The simple construction of providing notches at the corners of each land so that the throttles formed by these will be in a deadline state at substantially the same displacement angle, so that the entire throttle body of the valve body and valve body It is possible to make a gradual transition from the sharp reduction area of the throttle area to the gradual reduction area, and the unstable characteristics that occur at the oil destination at this transition are effectively eliminated, and when using it in the power steering system, steering feel is reduced. The risk of giving the driver a feeling of strangeness due to a sudden change in sense is reduced. In addition, it is not necessary to form a notch with a complicated shape, and it is possible to reduce the diameter of the valve body and valve body. Furthermore, since there is no throttle that is always closed, there is no constant The present invention has excellent effects such as keeping the load low.

[Brief description of 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 in a linearly expanded state.

FIG. 3 is an operation explanatory view showing the hydraulic control valve according to the present invention in a linearly expanded state.

FIG. 4 is an operation explanatory view showing the hydraulic control valve according to the present invention in a linearly expanded state.

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

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

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

[Explanation of symbols]

 1 valve body 2 valve body 4a throttle part 4b throttle part 5 oil supply chamber 6 oil discharge chamber 7 oil supply chamber 8 oil supply chamber 10 land 20 land 21 land 40 notch part 41 notch part P hydraulic pump S power cylinder T oil tank

Claims (1)

[Claims for utility model registration] Claims: 1. A cylindrical valve body and a valve body, which are coaxially displaced relative to each other, are provided. An oil supply chamber connected to the hydraulic power source, an oil supply chamber connected to different oil destinations on both sides of the oil supply chamber, and an oil discharge chamber connected to the oil discharge destination on the other side of the oil supply chambers are provided in parallel between the lands. The feed hydraulic pressure to the feed destination is controlled by the change of the throttle area caused by the relative angular displacement in the throttle portion formed between the opposite corner portions of the land and communicating the chambers. In the hydraulic control valve described above, among the plurality of lands on the valve body side or the valve body side, a pair or a plurality of pairs of lands located to face each other in the radial direction have a width different from other lands. The narrowed state of the narrowed portion formed by each land including the land Hydraulic control valve, characterized in that it comprises a notch for the displacement angle ranging substantially the same.