JPH0717374A - Hydraulic pressure controller - Google Patents

Abstract

PURPOSE:To reduce the dimension of a driving means by continuously installing an inclined part having a shape for shifting an expander piston on the side where the capacity of a hydraulic pressure chamber increases, as a cam member separates from a flat part along the shift direction. CONSTITUTION:In the antilock control, a cam member 30 is driven by a motor 33, and a spherical body 34 is slidingly attached on the inclined part 35b of a cam surface 35. A cut valve 6 is closed by shifting an expander piston 8 to the side where the capacity of a hydraulic pressure chamber 7 increases. The hydraulic pressure acting on a wheel brake B is lowered by cutting off the part between an input port 4 and an output port 5 and increasing the capacity of the hydraulic pressure chamber 7 which communicates to the output port 5. Accordingly, the output torque necessary for the motor 33 in the drive of the expander piston 8 to the side where the capacity of the hydraulic pressure chamber 7 increases can be reduced relatively, and the reduction of the dimension of the motor 33 can be achieved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention has a casing having an input port and an output port, a cut valve for switching communication / interruption between the input port and the output port, and a fluid pressure chamber communicating with the output port with one end side thereof facing. Further, the present invention relates to a hydraulic pressure control device that includes an expander piston that closes the cut valve according to the movement of the hydraulic chamber toward the side where the volume increases, and a drive unit that drives the expander piston.

[0002]

2. Description of the Related Art Conventionally, such an apparatus is disclosed in, for example, Japanese Patent Laid-Open No.
It is known from JP-A-121963.

[0003]

Such a hydraulic control device is used, for example, as an anti-lock brake modulator, and the expander piston is moved to the side where the volume of the hydraulic chamber is increased to close the cut valve. In this case, the input port and the output port are shut off, and the output hydraulic pressure of the output port that communicates with the hydraulic chamber is reduced.In the above conventional type, the motor is connected to the expander piston via the ball screw. It is connected. Thus, when the cut valve is opened, the expander piston is acted on by the hydraulic pressure on the side that increases the volume of the hydraulic chamber, and the expander piston acts as a cut valve against the relatively large force. In order to maintain the valve in the open position, in the above-mentioned conventional one, the expander piston is urged to the side to open the cut valve by the backup spring having a relatively large spring force, and to the side to close the cut valve. In order to drive the expander piston, it is necessary to overcome the large spring force of the above-mentioned backup spring, and therefore the size of the drive means must be increased.

The present invention has been made in view of the above circumstances, and does not require a large force to hold the expander piston at the position where the cut valve is opened, so that the driving means can be downsized. An object is to provide a pressure control device.

[0005]

In order to achieve the above object, according to the present invention, the driving means slides on a sliding contact portion provided at the end of the expander piston on the side opposite to the hydraulic chamber. A cam member having a contacting cam surface and supported in a casing to enable movement in a direction orthogonal to the moving direction of the expander piston; and a drive source for driving the cam member, the cam surface comprising: A flat portion that is orthogonal to the moving direction of the expander piston is connected to a sloped portion that moves the expander piston toward the side that increases the volume of the hydraulic chamber as it moves away from the flat portion along the moving direction of the cam member. It will be constructed.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

1 to 3 show an embodiment of the present invention. FIG. 1 is a vertical sectional side view of a hydraulic pressure control device, FIG. 2 is an enlarged vertical sectional view of the vicinity of a cut valve, and FIG. 3 is a sectional view taken along line 3-3 of FIG.

First, in FIG. 1, the master cylinder M is
It is connected to the wheel brake B via the hydraulic pressure control device 1, and the output hydraulic pressure of the master cylinder M acts on the wheel brake B as it is during normal braking, but when the wheel is about to lock during braking. During antilock control,
The operation of the hydraulic pressure control device 1 controls the reduction, holding, and pressure increase of the braking hydraulic pressure applied to the wheel brakes B.

The hydraulic pressure control device 1 includes a casing 2 having an input port 4 and an output port 5, and a cut valve 6 for switching communication / interruption between the input port 4 and the output port 5.
And an expander piston that is slidably fitted to the casing 2 with one end facing the hydraulic chamber 7 and that closes the cut valve 6 in accordance with the movement of the hydraulic chamber 7 toward the side that increases the volume. 8 and a drive means 9 connected to the other end of the expander piston 8, a master cylinder M is connected to the input port 4, and a wheel brake B is connected to the output port 5.

The casing 2 includes first and second case members 10 and 11 connected to face each other, a third case member 12 connected to the first and second case members 10 and 11, and a third case member. Closure member 13 coupled to case member 12
It consists of and.

The first and second case members 10 and 11 are connected to each other to form a bottomed cylinder, and one end (the left end in FIG. 1) between the case members 10 and 11 is closed. A guide hole 14 having a rectangular cross section and an enlarged hole 15 having an inner surface enlarged than the guide hole 14 and connected to the other end of the guide hole 14 via a step portion 16 are formed. Third case member 1
2 is formed into a bottomed cylindrical shape having an end wall 12a at one end, and the end wall 12a closes the opening of the bottomed cylindrical portion formed by the first and second case members 10 and 11. In this way, it is connected to the first and second case members 10 and 11,
The closing member 13 is coupled to the third case member 12 so as to close the opening end of the third case member 12.

Referring also to FIGS. 2 and 3, the guide hole 1 is formed in the second case member 11 of the casing 2.
4, a slide hole 17 that opens in the inner surface of the guide hole 4 and extends in a direction orthogonal to the longitudinal direction of the guide hole 14, and a valve hole 18 that has a smaller diameter than the slide hole 17 are coaxially formed through a step portion 19. To be done. An expander piston 8 having an annular seal member 20 on the outer surface that slidably contacts the inner surface of the slide hole 17 is slidably fitted in the sliding hole 17, and the expander piston 8 and the step portion 19 are connected to each other. A hydraulic chamber 7 is formed between the two. Thus, the second
The output port 5 formed in the case member 11 is connected to the hydraulic chamber 7 and the wheel brake B.

The cut valve 6 has a tapered valve seat 21 provided in the second case member 11 by opening the valve hole 19 in the center, a valve body 22 that can be seated on the valve seat 21, and the valve. A valve spring 23 for urging the body 22 in a direction to be seated on the valve seat 21.
With.

The second case member 11 has a storage hole 24 coaxially connected to the large-diameter end of the valve seat 21, and an input port 4 coaxially connected to the outer end of the storage hole 24 and connected to the master cylinder M. And are drilled. On the inner surface of the storage hole 24, a plurality of axially extending guide protrusions 25 ... Are provided at intervals in the circumferential direction, and the valve body 22 is formed by the guide protrusions 25 ... It is accommodated in the accommodating hole 24 in such a manner that the seating on and the actuation from the valve seat 21 are guided. A retaining ring 26 is fitted in a portion of each of the guide protrusions 25 ... Near the input port 4, and the valve spring 23 is contracted between the retaining ring 26 and the valve body 22.

A rod 27, which is loosely inserted into the valve hole 18, is integrally connected to the valve body 22. On the other hand, the expander piston 8 is coaxially and integrally provided with a pressing shaft 28 that can be loosely inserted into the valve hole 18 so as to come into contact with the tip of the rod 27.
Therefore, when the expander piston 8 moves to the side that reduces the volume of the hydraulic chamber 7, as shown in FIG. 2, the cut valve 6 is in the open state in which the valve body 22 is separated from the valve seat 21, and the input port is opened. 4 is communicated with the output port 5 via the hydraulic pressure chamber 7, and when the expander piston 8 moves to the side that increases the volume of the hydraulic pressure chamber 7, the valve element 22 is moved by the spring force of the valve spring 23. The cut valve 6 is closed and the input port 4 and the output port 5 are shut off from each other.

The drive means 9 is capable of moving in a direction orthogonal to the moving direction of the expander piston 8 and is supported by the casing 2, and a cam member 30 via a ball screw 31 and a torque limit mechanism 32. And a motor 33 as a drive source connected to.

The cam member 30 is movably inserted into the guide hole 14 with a quadrangular cross-sectional shape. The cam member 30 has its both sides regulated by both inner side surfaces of the guide hole 14. The rotation operation is prohibited and the vehicle moves in the guide hole 14. On the other hand, at the end of the expander piston 8 on the side opposite to the hydraulic chamber 7, the spherical body 3 as a sliding contact portion is provided.
4 is fixed by, for example, caulking, and the cam member 30 is provided with a cam surface 35 for slidingly contacting the spherical body 34. The cam surface 35 has a flat portion 35a orthogonal to the moving direction of the expander piston 8 and an inclined portion 35b.
Are connected in series. Thus, the flat portion 35a is
When the spherical body 34 is in sliding contact with the flat portion 35a, the volume of the hydraulic chamber 7 is minimized and the expander piston 8 is held at the position where the cut valve 6 is opened.
The inclined portion 35b is formed so as to be inclined so as to move the expander piston 8 to the side where the volume of the hydraulic chamber 7 increases as it moves away from the flat portion 35a along the moving direction of the cam member 30.

On the side opposite to the cam surface 35, a sliding member 36 made of a material having wear resistance and a low friction coefficient is attached to the cam member 30, and the sliding member 36 is attached to the inner surface of the guide hole 14. Slidably contacted. As a result, the hydraulic chamber 7
Hydraulic fluid from the expander piston 8 to the cam member 30
Even when a pressing force is applied to the cam member 30, the smooth sliding motion of the cam member 30 in the guide hole 14 can be maintained.

The ball screw 31 has a male screw portion 37a engraved on the outer surface at one end side of a rotary shaft 37 that rotatably penetrates the end wall 13a of the third case member 13 and a plurality of balls 38 that circulate. The screw outer 39 is screwed to the male screw portion 37a, and the screw outer 39 is integrally connected to the cam member 30.
A bearing 40 is provided between a and the rotating shaft 37.

In such a ball screw 31, since the screw outer 39 is integral with the cam member 30 whose rotational operation is restricted by the guide hole 14, the rotational operation about the axis is prevented, and therefore the rotating shaft 37 is prevented. The screw outer 39 is actuated in the axial direction in response to the rotational movement of the above, and the cam member 30 integrated with the screw outer 39 is actuated in the guide hole 14 in the longitudinal direction.

The motor 33 is fixedly supported by the closing member 13 in the casing 2 coaxially with the rotary shaft 37, and the motor 33 is provided with an encoder 41 for detecting the rotational operation amount thereof. To be done.

The torque limit mechanism 32 includes a bottomed cylindrical outer housing 43 fixed to the output shaft 42 of the motor 33, and a plurality of friction plates 44 spline-connected to the open end side of the outer housing 43. , A plurality of friction plates 45 that are spline-coupled to the rotary shaft 37 and are alternately superposed with the friction plates 44, and a spring bearing member 46 fixed to the other end of the rotary shaft 37 are superposed alternately. 45, and a pair of coil springs 47, 48 compressed between the spring receiving members 46, and a plurality of friction plates 44 urged by the coil springs 47, 48. , 45 ... and a flange 50 provided on the rotary shaft 37 so as to receive the ...

According to the torque limit mechanism 32, when the load on the rotary shaft 37 is small, the output torque of the motor 33 is transmitted from the outer housing 43 to the rotary shaft 37 via the friction plates 44, ... When the load of 37 increases beyond a predetermined value, the friction plates 44, ..., 45
.. slips between them, which limits the upper limit of the torque transmitted from the motor 33 to the rotary shaft 37.

Next, the operation of this embodiment will be explained. During normal braking, the cam member 30 is driven by the operation of the motor 33 in the driving means 9 so that the spherical portion 34 is brought into sliding contact with the flat portion 35a of the cam surface 35. The expander piston 8 is moved to the side where the volume of the hydraulic chamber 7 is reduced to open the cut valve 6, and the input port 4 and the output port 5 are opened.
The brake fluid pressure from the master cylinder M is applied to the wheel brakes B by communicating the spaces.

At this time, since the spherical body 34 provided on the expander piston 8 is in sliding contact with the flat portion 35a which is parallel to the moving direction of the cam member 30, the force for pressing the cam member 30 in the moving direction is exerted. The expander piston 8 does not act on the cam member 30, thus eliminating the need for a backup spring conventionally used to hold the cut valve 6 open.

During antilock control, the motor 33
To drive the cam member 30 to drive the inclined surface 35 of the cam surface 35.
The spherical body 34 is slidably contacted with b, the expander piston 8 is moved to the side where the volume of the hydraulic chamber 7 is increased, the cut valve 6 is closed, and the input port 4 and the output port 5 are shut off. By increasing the volume of the hydraulic chamber 7 communicating with the output port 5, the hydraulic pressure acting on the wheel brake B can be reduced. At this time, since the urging force on the side that reduces the volume of the hydraulic chamber 7 does not act on the expander piston 8, a motor is used to drive the expander piston 8 to the side that the volume of the hydraulic chamber 7 increases. The output torque required by the motor 33 is relatively small and the motor 33
Can be downsized.

Further, by changing the inclination angle of the inclined portion 35b on the cam surface 35 or changing the inclination degree of the inclined portion 35b on the way, the expander piston 8 moves according to the operation of the motor 33. It is possible to change the amount, that is, the depressurization characteristic of the hydraulic chamber 7, whereby the antilock control characteristic can be changed.

Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above embodiments, and various small design changes can be made without departing from the present invention described in the claims. It is possible to

For example, instead of the spherical body 34, a roller is axially supported by the expander piston 8, and the roller is supported by the cam surface 35.
You may make it make a rolling contact.

[0030]

As described above, according to the present invention, the drive means has the cam surface which is in sliding contact with the sliding contact portion provided at the end of the expander piston on the side opposite to the hydraulic chamber. The expander piston is provided with a cam member supported in the casing so as to be movable in a direction orthogonal to the moving direction, and a drive source for driving the cam member, the cam surface being orthogonal to the expander piston moving direction. The cut valve is formed by connecting the inclined portion having a shape for moving the expander piston to the side where the volume of the hydraulic chamber increases as the distance from the flat portion increases along the moving direction of the cam member. In the valve open state, the force acting on the expander piston on the side that increases the volume of the hydraulic chamber does not act to drive the cam member in its moving direction, and therefore the force required on the drive means side. To Comparatively to the drive means can be downsized small and by using a shape of the inclined portion are different cam member, it is possible to change the pressure reduction characteristics of the hydraulic chamber.

[Brief description of drawings]

FIG. 1 is a vertical side view of a hydraulic control device.

FIG. 2 is an enlarged vertical sectional view of the vicinity of a cut valve.

FIG. 3 is a sectional view taken along line 3-3 of FIG.

[Explanation of symbols]

 1 ... Liquid pressure control device 2 ... Casing 4 ... Input port 5 ... Output port 6 ... Cut valve 7 ... Hydraulic chamber 8 ... Expander piston 9 ... Drive Means 30 ... Cam member 33 ... Motor as drive source 34 ... Spherical body as sliding contact portion 35 ... Cam surface 35a ... Flat portion 35b ... Sloping portion

Claims (1)

[Claims] 1. A casing (2) having an input port (4) and an output port (5), and an input port (4).
And a cut valve (6) for switching between communication and cutoff between the output port (5) and a hydraulic chamber (7) communicating with the output port (5)
And an expander piston (8) for closing the cut valve (6) in accordance with the movement of the hydraulic chamber (7) toward the side where the volume of the hydraulic chamber (7) is increased. In the hydraulic pressure control device comprising a drive means (9) for driving the hydraulic pressure control device, the drive means (9) is slidably provided on the end of the expander piston (8) on the side opposite to the hydraulic pressure chamber (7). A cam member (30) having a cam surface (35) slidably contacting the portion (34) and capable of moving in a direction orthogonal to the moving direction of the expander piston (8) and being supported by the casing (2); And a drive source (33) for driving the cam member (30), the cam surface (35) being a flat portion (35) orthogonal to the moving direction of the expander piston (8).
In (a), the inclination of the shape that moves the expander piston (8) to the side where the volume of the hydraulic chamber (7) increases as it moves away from the flat portion (35a) along the moving direction of the cam member (30). A hydraulic control device comprising a portion (35b) connected in series.