JPS6211723Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a hydraulic control valve used in a two-system control system in which the brake fluid pressure generated in a master cylinder is transmitted to the left and right rear wheels of a vehicle through two independent piping systems. It is something.

In a vehicle, the master cylinder and the wheel cylinders provided on the left and right rear wheels of the vehicle are connected by two mutually independent piping systems, and the braking fluid pressure generated in this master cylinder based on the operation of the brake operating member is are transmitted to each of the wheel cylinders independently from each other.

The applicant previously proposed a system in which valve pistons of a pair of proportioning valves were installed in parallel in a single housing as valves for controlling the brake fluid pressure transmitted to the left and right rear wheels in such a two-system control system. , developed a common biasing mechanism for both valve pistons, and filed an application for utility model registration on December 27, 1981 (Utility Model Application No. 191230; Utility Model Application No. 1982).
No. 111654). This is because the biasing mechanism of the pair of valve pistons is supported such that (a) one end thereof is swingable in a direction parallel to a plane containing the axes of the two valve pistons by a pivot at an intermediate position between the two valve pistons; (b) a sliding member comprising a cylindrical part slidably fitted to the guide rod and an action part that can come into contact with the rear ends of both the valve pistons; (c)
(d) a spring installed between the sliding member and the guide rod, which always applies a constant biasing force to the ends of the valve pistons via the sliding member; and (d) by the pivot of the guide rod. The guide rod extends toward the housing from one supported end, and is fitted into a stopper hole formed in the housing parallel to the valve piston with a predetermined clearance, thereby controlling the swinging of the guide rod. The valve piston is characterized by including a stopper protrusion that limits the angle range to a minute range centered on a straight line that passes through the axis and is parallel to the axes of both valve pistons.

In this hydraulic control valve, the elastic force of one spring is equally distributed to the pair of valve pistons by a sliding member, and the discrepancy in the operating strokes of the pair of valve pistons due to manufacturing errors is eliminated. It is absorbed by the minute angle of rocking of the moving member and guide rod. Moreover, if one of the two independent piping systems is damaged, the sliding member will slide linearly on the guide rod, which is prevented from swinging beyond a certain limit by the stopper.
The valve piston that receives the hydraulic pressure of the piping system on the normal side compresses the spring by itself, so the hydraulic control start pressure on the normal side increases approximately twice as much as when both systems are normal. can get. In addition, the guide rod can be simply attached to the housing or a member fixed thereto by a pivot shaft, and the sliding member can be slidably fitted to the outside of the bar-shaped guide rod, making manufacturing easy. .

The present invention achieves such effects, and
It is possible to downsize, has higher mass productivity, and
The purpose of this is to provide a hydraulic control valve with good sealing performance, and its gist is that the biasing mechanism for a pair of valve pistons is (a) shaped like a container, and connected to both valves in a housing. (b) a cover fixed to the housing so as to cover the surface from which the rear end of the piston protrudes; and (b) the housing on the side wall of the cover is attached to a portion of the side wall of the cover that faces each other at an intermediate position between the two valve pistons. a pair of U-shaped notches cut in a direction parallel to the axis of the valve piston from an end surface in close contact with the valve piston; (c) the side wall is left uncut on the outside of the pair of U-shaped notches; (d) a pair of closing portions configured to close the U-shaped notch on the outer surface side of the housing;
a pivot whose both ends are supported by the bottoms of the pair of U-shaped notches and whose axial movement is prevented by being sandwiched from both sides by the pair of closing parts; and (e) whose one end is supported by the pivot. a guide rod rotatable in a direction parallel to a plane containing the axis of the valve piston; (f) a cylindrical portion slidably fitted to the guide rod; (g) a spring that presses the sliding member against the two valve pistons and applies the biasing force to the two valve pistons via the sliding member; (H) In order to limit the rotational movement of the guide rod to a predetermined angular range about a straight line passing through the axis of the pivot shaft and parallel to the axes of both valve pistons, and a pair of stoppers fixed to the cover so as to face each other at a predetermined distance from the cover.

In this way, the guide rod will be pivotally supported by the cover, so there is no need to secure a place for installing the guide rod in the part of the housing between the two valve pistons, and the distance between the two valve pistons can be reduced. By narrowing the width, the width dimension of the hydraulic pressure control valve can be reduced, and the weight and installation volume can be reduced.

Further, since there is no need to provide the housing with ears or the like for supporting the guide rod, the manufacturing and machining of the material for the housing are facilitated, and the degree of freedom in design is increased. Further, since both the stopper and the pivot support are provided on the cover, the accuracy of regulating the rotation angle of the guide rod and the sliding member can be improved.

Moreover, when pivoting the guide rod to the cover, if both ends of the pivot are inserted into the U-shaped notch with the pivot inserted through the guide rod, the U-shaped notch can be inserted into the guide rod.
The closing portions that close the outside of the letter-shaped notch sandwich the pivot from both sides and prevent its movement in the axial direction. Therefore, there is no need to provide a special member such as a snap spring to prevent the axis from moving.
It is possible to achieve the effects of reducing costs and facilitating assembly work.

Furthermore, although the pivot is supported by the cover, the U-shaped notch that supports it is blocked by the closing part on the outer surface of the cover as described above, so when the cover is fixed to the housing, the pivot Since the vicinity of the supporting part of the cover is completely covered, there is no need to provide a sealing means between the pivot and the cover, unlike when the pivot is supported by inserting it into a through hole formed in the cover, and from this point of view, costs are also reduced. This can be reduced.

Furthermore, since the U-shaped notch is cut in a direction parallel to the axis of the valve piston from the end surface of the cover that is in close contact with the housing, it can be formed when the cover is molded, which has the effect of omitting cutting work. You can also get

In short, according to the present invention, the above-mentioned Utility Application No. 55-
A hydraulic control valve that has the effects of the invention of No. 191230, can be miniaturized, is highly mass-producible, and has good sealing performance can be obtained.

Hereinafter, embodiments of the present invention will be explained in detail based on the drawings.

In FIG. 1, reference numeral 10 denotes a master cylinder, which generates equal hydraulic pressure in pressurizing chambers 14 and 16, which are independent of each other, in response to the depression force of the brake pedal 12. The hydraulic pressure generated in the first pressurizing chamber 14 is
8 to the inlet port 22 of the hydraulic control valve 20, and then via the outlet port 24 and the conduit 26 to the wheel cylinder 28 of the left front wheel, or via the outlet port 30 to the wheel cylinder 32 of the right rear wheel, respectively. communicated. The hydraulic pressure generated in the second pressurizing chamber 16 of the master cylinder 10 is also connected to the pipe line 34, the inlet port 22, the outlet ports 24 and 30, and an inlet port and two outlet ports provided at symmetrical positions. is transmitted to the wheel cylinder 40 of the right front wheel and the wheel cylinder 42 of the left rear wheel through the pipes 36 and 38, respectively, but these ports are not shown in the figure (the right side in the upper part of Fig. 1). (Half of the figure shows an outline drawing including the shape of the mounting part of the hydraulic control valve.)

The hydraulic control valve 20 includes two P valves 43 and 44 arranged in parallel with each other, and valve pistons 46 and 48 of the P valves 43 and 44 are biased by a bias mechanism 50. There is.

The valve piston 46 is accommodated in a longitudinal stepped hole 54 provided in the housing 52, and is slidably fitted into a central hole of a sleeve 56 that is threaded into the opening of the stepped hole 54. Further, the rear end portion (lower end in the figure) is made to protrude from the sleeve 56. The sleeve 56 has a concave portion on its end face on the side of the inlet chamber 66, and an oil seal 58 is disposed within the concave portion to ensure oil tightness between the sleeve 56 and the valve piston 46. A seal cover 60 is attached to the oil seal 5 in the recessed portion.
It is fixed so as to cover 8. A valve seat 62, which is a cap-shaped elastic body, is disposed in a stepped portion formed on the inner circumferential surface of the stepped hole 54, and the valve seat 62 and the valve element 64 of the valve piston 46 are brought into close contact with each other or separated from each other. The inlet chamber 66 and the outlet chamber 68 are communicated with each other and shut off. Incidentally, although not shown, a stepped hole, a sleeve, an oil seal, and a valve seat having the same structure are arranged symmetrically with the stepped hole 54 and the like.

The bottom surface of the housing 52 (valve piston 46,
A cover 70 that has a container shape and covers the bottom surface of the container 48 is fixed to the surface from which the rear end portion of the container 48 projects. The cover 70 is fixed by its flange portion 72.
This is accomplished by bolts 75 inserted into a pair of bolt holes 74 provided at appropriate locations (see FIG. 3). The housing 52 side (first side) of this cover 70
A pair of U-shaped recesses 76, 76 facing each other are formed on the inner wall surface of the end (upper side in the figure, hereinafter simply referred to as upper side) at a location midway between the pair of valve pistons 46, 48. ing. That is, both valve pistons 4 on the side wall of the cover 70
A pair of U-shaped notches are formed in opposing portions of the valve pistons 6 and 48 at intermediate positions thereof, and are cut in a direction parallel to the axes of the valve pistons 46 and 48 from the end surfaces of the side walls that are in close contact with the housing 52. The outer surface side of the side wall is left uncut and serves as a closing portion that closes off the U-shaped notch.

As shown in FIG. 2, the recessed portions 76, 76 have cylindrical bearings 82, 82 fitted at both ends with a pivot pin 80, which is a pivot for rotatably supporting the guide rod 78. Supported through. The guide rod 78 is integrally provided with a head 84 at one end thereof, which is a projection projecting outward in the radial direction of the guide rod 78, and a pin 80 inserted through the head 84 allows the valve pistons 46, 48 to be connected to each other. The other end (free end) is supported rotatably parallel to the plane containing the axis of
are opposed to each other with a predetermined gap between opposing stopper portions 86 provided on the bottom inner wall surface of the cover 70. The stopper portion 86 is connected to the guide rod 7
In order to suppress the rotation of the valve piston 8 within a certain range, when the angle formed between the axis of the guide rod 78 and a straight line passing through the axis of the pin 80 and parallel to the axes of the valve pistons 46 and 48 reaches a certain value. guide rod 78
It acts to prevent further rotation by coming into contact with. A sliding member 90 having a cylindrical portion 88 having a stepped portion 92 on its outer peripheral surface is fitted into the guide rod 78 . Stepped portion 9 in cylindrical portion 88
2 is in contact with one end of a coil spring 94 disposed on the outer periphery thereof and receives the biasing force of the coil spring 94. The other end of the coil spring 94 is received by a seat plate 96 fitted into the free end of the guide rod 78, and the seat plate 96 is supported by a snap ring 98 fitted into an annular groove formed in the guide rod 78. There is. Cylindrical part 88
The large diameter section 100 at the upper end accommodates the head 84 of the guide rod 78 and has a pair of upwardly open U's on opposing side walls as shown in FIG.
It is provided with letter-shaped notch grooves 102, 102. The notch grooves 102, 102 are formed in the bearings 82, 8.
A width dimension and a bottom curvature radius approximately equal to the radius of the bearing 82 are formed so as to sandwich the guide rod 2 with a small gap, thereby preventing rotation of the sliding member 90 about the axis of the guide rod 78. The bottoms of the U-shaped cutout grooves 102, 102 are set to a depth that does not interfere with the bearing 82 when the inner stepped portion 104 of the cylindrical portion 88 is in contact with the head 84 of the guide rod 78. A working portion 106 is provided to protrude from the large diameter portion 100 of the cylindrical portion 88 in the radial direction thereof. This acting portion 106 contacts the rear end portions (lower end portions) of the valve pistons 46, 48, and applies the biasing force of the spring 94 to the pair of valve pistons 46, 48.

Next, the operation of the hydraulic control valve 20 having the above configuration will be explained.

First, when the brake pedal 12 is depressed, the first and second pressurizing chambers 14, 1 of the master cylinder 10
A hydraulic pressure equal to 6 is generated. First pressurization chamber 1
The hydraulic pressure generated at 4 is transmitted to the inlet chamber 66 via the conduit 18 and the inlet port 22. Furthermore, this oil pressure is transmitted to the wheel cylinder 28 of the left front wheel via the outlet port 24 communicating with the inlet chamber 66 and the conduit 26. Further, the oil pressure in the inlet chamber 66 is controlled by the outlet chamber 68,
It is also transmitted to the wheel cylinder 32 of the right rear wheel via the outlet port 30 and the conduit 108, thereby braking the wheels. Note that the second pressurizing chamber 1 of the master cylinder 10
The hydraulic pressure generated at 6 is similarly transmitted to the wheel cylinders 40 and 42 of the front right wheel and the rear left wheel.

The oil pressure transmitted to the inlet chamber 66 and the outlet chamber 68 continues to increase as the brake pedal 12 is depressed, but when this oil pressure exceeds a set constant value, the valve piston is Since the pushing force applied to the valve 46 overcomes the urging force by the urging mechanism 50, the valve 6
4 is moved and seated on the valve seat 62. At this point, the communication between the inlet chamber 66 and the outlet chamber 68 is temporarily cut off, but when the oil pressure in the inlet chamber 66 further increases, the valve element 64 is again separated from the valve seat 62, and the oil pressure in the outlet chamber 68 is also increased. If the oil pressure in the outlet chamber 68 increases further, the valve element 64 will return to the valve seat 6.
2, and this process is then repeated to perform well-known hydraulic control operations.

By the way, the pair of valve pistons 46 and 48 are designed so that their operating strokes (travel amounts) are the same, but they do not necessarily match due to manufacturing errors and the like. That is, even if one valve piston (for example, the valve piston 48 on the right in the figure) is seated on the valve seat, the valve element 64 of the other valve piston 46 may not be seated on the valve seat 62 yet. In this case, since the oil pressure in the outlet chamber 68 continues to increase, the amount of extrusion of one valve piston 46 becomes larger than that of the other, but at this time, the sliding member 90 and the guide rod 78 move toward both valve pistons 46 and 48. It is rotated counterclockwise in FIG. 1 to a position where the biasing forces are equal, thereby eliminating the unbalance of both forces, thereby acting to transmit equal control hydraulic pressure to the left and right rear wheels. In this case, the guide rod 78 does not come into contact with the stopper portion 86. Stopper part 86
The gap between the guide rod 78 and the guide rod 78 is thus preselected.

Next, one of the pair of piping systems, for example conduit 34
If an oil leak occurs in the master cylinder 10,
The hydraulic pressure generated is transmitted to only one inlet port 22 via the conduit 18. When the oil pressure in the outlet chamber 68 exceeds the set value, only the pushing force of the valve piston 46 acts on the acting portion 106 of the sliding member 90. Therefore, the sliding member 90 and the guide rod 7
8 receives the pushing force from one of the valve pistons 46 and is rotated significantly counterclockwise in FIG. Here, the sliding member 9
0, further rotation of the guide rod 78 is prevented. Furthermore, even at this stage, the valve element 64 is attached to the valve seat 6.
I haven't reached the point where I can sit in 2nd place. The oil pressure in the outlet chamber 68 is further increased, and when the pushing force of the valve piston 46 based on this oil pressure overcomes the urging force, the valve piston 46 is pushed out while sliding the sliding member 90 downward.
The valve element 64 comes to be seated on the valve seat 62. At this point, a known hydraulic control operation is started for the first time. At this time, the oil pressure in the outlet chamber 68 is such that the valve piston 46 is solely subjected to the biasing force of the coil spring 94, so the above control operation is not performed until the oil pressure in the outlet chamber 68 is twice the normal level. Therefore, the hydraulic control start value of the hydraulic pressure transmitted to the wheel cylinder 32 of the right rear wheel is approximately twice as large as the normal value.

By the way, the control valve 20 has a valve piston 4.
A major feature is that a biasing mechanism 50 for biasing 6 and 48 is attached to the cover 70 side. The biasing mechanism 50 can also be attached to the housing side, and in fact, the applicant has developed and filed an application for a hydraulic control valve in which the biasing mechanism is attached to the housing side. The above-mentioned Utility Application No. 191230 (Sho 57-
111654).

However, when the biasing mechanism is attached to the housing side, a space must be secured on the housing side to provide a pivot for supporting the biasing mechanism. Since this pivot is provided at an intermediate position between the pair of valve pistons, it is inevitably necessary to widen the interval between the valve pistons, which increases the width of the control valve itself, leading to an increase in its size. On the other hand, if the pivot shaft is provided on the cover side, the space described above is not required and the control valve can be made more compact. Furthermore, in the above device, since the stopper part 86 is provided on the cover 70, which is the same member on which the pin 80 is provided, it is easier to assemble the control valve than when it is provided on the housing side, which is a separate member. This has the advantage that the influence of assembly errors can be avoided, the relative dimensional accuracy between the stopper part and the guide rod can be increased, and the accuracy can be checked before assembly. Moreover, since the stopper portion 86 is provided near the bottom of the cover 70 that is farthest in the axial direction from the pin 80, which is the center of rotation of the guide rod 78, the permissible rotation range of the guide rod 78 can be defined more accurately.

The control valve 20 further has various features described below.

That is, the U-shaped concave portion 76 that supports the pivot pin 80 is formed by die-casting or the like to form the cover 7.
Since it is formed at the same time as molding the pivot pin 80, cutting work to form a hole etc. for supporting the pivot pin 80 can be omitted, reducing machining time and machining cost, and the concave portion 76 opens toward the housing 52 side. Since it is U-shaped, pivot pin 8
0 into a through hole formed at one end of the guide rod 78 and fitting both ends of the pivot pin 80 into the recessed fitting portions 76, 76, making assembly easy and reducing assembly man-hours. . In addition, since the pin 80 is prevented from moving in the axial direction simply by fitting it into the recessed fitting portions 76, 76, pin positioning parts and the like required when passing the pin through the pin hole are not required, thereby reducing costs. This contributes to reducing the amount of heat and improving ease of assembly. Moreover, the U-shaped pin supporting recess 7
6 and 76 are located on the inner wall surface of the cover 70 and do not penetrate the outer wall surface, so the sealing performance is high, and there is also an advantage that a sealing member and its attachment work are not required.

Next, the guide rod 78 is provided at one end with a head 84 that projects radially outward of the guide rod 78, and this head 84 is adapted to abut an inner stepped portion 104 of the sliding member 90. A seat plate 96 is attached to the other end of the guide rod 78 to receive one end of a spring 94.
6 and an outer stepped portion 92 of the cylindrical portion 88, a spring 94 is set therebetween. Therefore, the guide rod 78 constituting the biasing mechanism 50,
The sliding member 90 and the spring 94 can be preassembled and prepared as sub-assemblies before they are attached to the cover 70, and since the spring 94 can be preloaded, the control valve 20
When assembling the control valve 20, the desired setting load can be applied by pushing it in slightly, thereby greatly improving the workability of assembling the control valve 20. Also, when applying a preload to the spring 94,
Since it is possible to check whether this load is at a set value and to adjust it by inserting a spacer shim, etc., a stable biasing force can be applied at the stage when the control valve 20 is assembled. Variations in control performance between valves can be reduced.

Furthermore, the spring 9 when assembling the control valve 20
Since the necessary compression amount of valve pistons 46 and 48 is small, there is less risk of the valve pistons 46 and 48 being twisted during assembly, compared to when the valve pistons 46 and 48 are compressed from their free length by bolt tightening or the like. Therefore, especially when the valve piston 46 is made of a soft metal such as an aluminum alloy, deformation and scratches due to the twisting between the valve piston 46 and the sleeve 56 etc. are prevented from occurring, and the P valve is Does not cause changes in operating characteristics. Also, the spring 94 itself is connected to the guide rod 7.
8. Since the structure is such that it can rotate together with the sliding member 90, one end of the spring 94 is connected to the cover 7.
Compared to the case where the valve piston is fixed at 0, the spring itself receives a bending load when the guide rod 78 etc. rotates, and there is no difference in the biasing force applied to the pair of valve pistons.

Next, the sliding member 90 has a pair of U-shaped notch grooves 102, 102, where the bearings 82, 82
The sliding member 90 is positioned (prevented from rotating) by being sandwiched therebetween. The sliding member 90 is
06 and the valve pistons 46, 48, but in this case, a prying force acts on the valve pistons 46, 48, making their operation unstable, and the valve pistons 46, 48 become unstable.
If valve pistons 6 and 48 are made of a soft metal such as an aluminum alloy, there is a risk that the valve pistons 46 and 48 will be scratched or abnormally worn. On the other hand, in the control valve 20 described above, the valve piston is not involved in positioning the sliding member 90, so there is no risk of the above-mentioned problem occurring, and the control characteristics of the hydraulic control valve 20 do not change. Moreover, there is an advantage that the shape of the acting portion 106 is simple.

Next, another embodiment of the present invention will be described based on FIGS. 6 to 9.

In this embodiment, the head 11 of the guide rod 110
2 is a sliding member 11 formed in the shape of a hexagonal column;
The inside of the large diameter portion 118 of the cylindrical portion 116 at 4 is a hexagonal fitting hole 119 into which the head 112 is fitted, thereby preventing relative rotation between the two. As shown in FIG. 9, a thread 111 is cut into the other end of the guide rod 110, and a nut 120 having a stepped portion 113 on its outer circumference is screwed into this thread 111. The stepped portion 113 of the nut 120 receives the seat plate 122.
One end of a spring 124 is applied to 2.

In this embodiment, since the spring 124 is compressed by tightening the nut 120, there is an advantage that the gradually increasing preload can be adjusted to a desired value by measuring it in an appropriate manner. Natsu 1
After the position of the nut 120 is determined, insert the guide rod 11 through the hole 126 penetrating the peripheral wall of the nut 120.
By crushing the screw 111 of 0, the nut 120 is fixed there and the spring 124 is fixed during hydraulic control operation.
This prevents the biasing force from changing. Note that since the sliding member 114 is fitted with the head 112 of the guide rod 110, the two are not rotated relative to each other when the nut 120 is tightened.

The above-mentioned embodiment is merely one embodiment of the present invention, and various modifications may be made to the present invention without departing from the spirit thereof.

For example, the above embodiment describes a so-called P-valve, which, like the P-valve, has two valve pistons with one end protruding, so that despite an increase in the supplied hydraulic pressure, no pressure is applied to the valve piston. The biasing mechanism of the present invention can also be applied to a limit valve (L valve) that outputs a constant pressure of hydraulic pressure corresponding to a biasing force.

[Brief explanation of the drawing]

Fig. 1 is a cutaway front view showing the main parts of a hydraulic control valve that is an embodiment of the present invention, Fig. 2 is a bottom cross-sectional view of the main parts of the control valve, and Figs. 3 to 5 respectively show the same control valve. FIG. 3 is a perspective view of the cover, guide rod, and sliding member of the valve. 6 and 7 are respectively a bottom sectional view and a front sectional view of a main part of a hydraulic control valve according to another embodiment of the present invention, and FIGS. 8 and 9 are a sectional view of a main part, respectively.
FIG. 3 is a perspective view of the sliding member and guide rod shown in the figure. 10... Master cylinder, 12... Brake pedal, 18, 26, 34, 36, 38, 108...
... Pipe line (piping), 20 ... Hydraulic control valve (hydraulic pressure control valve), 28, 32, 40, 42 ... Wheel cylinder, 46, 48 ... Valve piston, 50 ...
Biasing mechanism, 52... Housing, 70... Cover, 76... Recessed fitting part (U-shaped notch), 78, 11
0... Guide rod, 80... Pivot pin (axis), 86... Stopper part, 88, 116... Cylindrical part, 90, 114... Sliding member, 94, 124
...Coil spring, 106...Action part.

Claims (1)

[Scope of Claim for Utility Model Registration] Braking fluid pressure generated in a master cylinder based on the operation of a brake operating member is transmitted to wheel cylinders provided on the left and right rear wheels of a vehicle through two independent piping systems. In the rear independent dual system control system, a pair of valve pistons for controlling braking fluid pressure transmitted to the wheel cylinders of the left and right rear wheels are arranged in parallel in a single housing, and their rear ends protrude from the housing. The hydraulic control valve is of a type in which a biasing force is applied in a direction toward the inside of the housing by a biasing mechanism, wherein the biasing mechanism is (a) shaped like a container; (b) a cover fixed to the housing so as to cover a surface from which rear end portions of the valve pistons of the housing protrude; and (b) a side wall of the cover facing each other at an intermediate position between the valve pistons. a pair of U-shaped notches cut in a direction parallel to the axis of the valve piston from an end surface of the side wall that is in close contact with the housing; a pair of closing parts that are left uncut and close the U-shaped notches on the outer surface of the housing; (d) both ends of which are supported by the bottoms of the pair of U-shaped notches; (e) a pivot shaft which is sandwiched from both sides by a pair of blocking parts and prevented from moving in the axial direction; (f) a sliding member comprising a cylindrical portion slidably fitted to the guide rod and an action portion capable of abutting against the rear ends of the two valve pistons; ) a spring that presses the sliding member against the valve pistons and applies the biasing force to the valve pistons via the sliding member; The guide rod is fixed to the cover so as to face the free end of the guide rod at a predetermined distance from both sides so as to be limited to a predetermined angular range centered on a straight line that passes through the valve pistons and is parallel to the axes of both valve pistons. 1. A hydraulic pressure control valve for a rear independent two-system control operation device, comprising a pair of stoppers.