JPH02189260A - Hydraulic controller - Google Patents

Abstract

PURPOSE:To aim at promotion of miniaturization in a controller and its low-unit cost of production by installing a guide piston fitted with an inner piston in a cylinder, while having each one end of both these pistons opposed to a hydraulic chamber and the other to a control chamber, respectively, and constituting them so as to perform their hydraulic control. CONSTITUTION:A guide piston 81 is installed in a large diametral part 77 of a stepped cylinder 75, having a small diametral part 76 and this large diametral part 77 and installing a fixed valve seat 78 between them, and a recess part 82 is installed in one side directed to the side of the small diametral part 76 of this guide piston 81 and a tubular projection 83 is projectingly installed in the other side. Then, an inner piston 86 is fitted in the recess 82, and each one end of both these pistons 81, 86 is opposed to a hydraulic chamber 87 ranging to a master cylinder M/C and a wheel cylinder W/C, and the other end is opposed to a control chamber 88 ranging to an auxiliary hydraulic source. Afterward, interconnection between the master cylinder M/C and the wheel cylinder W/C is interrupted by engagement between the fixed valve seat 78 installed in an edge of the large diametral part 77 and one end of the guide piston 81.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a hydraulic pressure control device, and is particularly suitable as a hydraulic pressure control device for slip control that prevents slippage between wheels and a road surface when a vehicle accelerates or starts. The present invention relates to available hydraulic control devices.

[Conventional technology]

Conventionally, a patent application has been made for a hydraulic control device that is equipped with an anti-lock control device that prevents slippage between the wheels and the road surface when the vehicle is braking, and a traction control device that prevents the wheels and the road surface from slipping when the vehicle accelerates or starts. 63-4304
There is a device described in No. 2 (unpublished).

As shown in FIGS. 3 and 4, this device connects the mask cylinder 1 to the input port IO of the first cylinder 5,
The output port II of the first cylinder 5 is connected to the bypass port 25 of the fail-safe cylinder 20, and the first cylinder 5
Distribution path 1 connecting input boat IO and output port 11 of
2 is provided with a first valve 13.

Then, the first piston 6 is fitted into the first cylinder 5,
Connecting the hydraulic chamber 8 of the first cylinder 5 to the output port 11,
The control chamber 9 is connected to the auxiliary hydraulic pressure source 50 via the on-off valve 61, and the on-off valve 66 and the on-off valve 71 are successively connected to the reservoir 53, so that the first piston 6 is moved by the hydraulic pressure in the control chamber 9. While moving forward and reducing the hydraulic pressure chamber 8, the first
The first valve 13 is opened by the valve lever 7 of the piston 6 against the spring force of the first valve spring 14. Further, the first piston 6 is moved back due to the pressure reduction in the control chamber 9, and the first valve 13 is closed.

Further, the communication boat 15 that communicates with the human-powered boat 10 of the first cylinder 5 is connected to the input boat 23 of the fail-safe cylinder 20. This failsafe shilling 20
A fail-safe piston 21 is fitted therein, and the control chamber 27 of the fail-safe cylinder 20 is always connected to the auxiliary hydraulic pressure source 5.
0, and the fail-safe piston 21 presses the fail-safe valve 24 with the valve rod 22 by this hydraulic pressure,
The input boat 23 of the fail-safe cylinder 20 is always closed.

The bypass outlet 26 communicating with the bypass port 25 of the fail-safe cylinder 20 is connected to the input boat 38 of the stepped cylinder 32, and the stepped cylinder 32 has a large diameter part with a cross-sectional area of A2 and a small diameter part with a cross-sectional area of A1. It becomes more.

A cylindrical guide piston 33 is slidably fitted into the large diameter portion, and a traction piston 35 is slidably fitted into the small diameter portion.

The guide piston 33 is pressed by a sorting spring 34 and the traction piston 35 is pressed by a piston spring 36 toward the control chamber 43 side of the stepped cylinder 32.

The manual boat 38 of the stepped cylinder 32 is connected to an output port 39, and the output port 39 is connected to the rear side (driven wheel) wheel cylinder W/C (Rr) via a proportioning valve (PCV). There is.

Further, the output port 39 is connected to the traction valve seat 3
3 is connected to the large diameter hydraulic pressure chamber 42 through a communication passage 41 formed inside the wheel, and the hydraulic chamber 42 is connected to the front wheel side (driving wheel) wheel cylinder W/C via the second output boat 40. Fr), and the control chamber 43 of the stepped cylinder 32 is connected to the on-off valve 66.
, the control chamber 9 of the first cylinder 5 , and the on-off valve 61 in this order to the auxiliary hydraulic pressure source 50 , and the on-off valve 71 to the reservoir 53 .

Further, the auxiliary hydraulic pressure source 50 is connected to the pump 52 from the reservoir 53,
A motor 54, which is connected to an accumulator 56 via a check valve 51 in turn and drives a pump 52, is connected to a power source via a switch 55 responsive to hydraulic pressure.

The above configuration constitutes a hydraulic pressure control device for wheel slip control.

In this device, first, pressure liquid is supplied to the on-off valve 6 from the auxiliary hydraulic pressure source 50.
1 and is press-fitted into the control chamber 9 of the first cylinder 5, the first piston 6 moves forward, and the first valve 13 of the flow path 12 is prepared to be opened.

Then, when the brake pedal is stepped on, the pressure fluid in the master cylinder 1 reaches the input boat 38 of the stepped cylinder 32 from the input boat 1O1 flow passage 12 of the first cylinder 5 and the output port 11, and furthermore, the pressure fluid in the input boat 38 is the boil cylinder (Y/C) of the driven wheel on the rear wheel side from the output port 39
At the same time, it is press-fitted into the wheel cylinder (W/C) of the driving wheel on the front wheel side through the communication passage 41 and the second outlet boat 40, and the wheels are respectively braked.

When the wheels move towards locking, the on-off valve 61 is closed and the on-off valve 66 is opened according to a command from an electronic control device (not shown).
Pressure fluid in the control chamber 9 of the first cylinder 5 is discharged to the reservoir 53, the first piston 6 moves back, and the flow path 12 is closed. Furthermore, when the pressure fluid in the control chamber 9 is discharged to the reservoir 53, the first piston 6 is further retreated, the hydraulic chamber 8 of the first cylinder 5 is expanded, and the pair of foil cylinders (W/C)
The hydraulic pressure will drop and the risk of wheel locking will be avoided.

When there is no longer any risk of wheel locking, the on-off valve 66 is closed, the first piston 6 is stopped, and the wheel cylinder (W/C) is closed.
The hydraulic pressure is kept constant.

Further, when the on-off valve 61 is opened, the hydraulic pressure in the wheel cylinder (W/C) rises again due to the movement of the first piston 6, and the brake is applied.

Next, when a slip occurs between the driving wheels and the road surface during acceleration or starting, the on-off valve 71 is closed and the on-off valve 66 is opened in response to a command from an electronic control device (not shown), and the auxiliary hydraulic pressure source 50
The pressure fluid is introduced into the control chamber 43 of the stepped cylinder 32 to move the traction piston 35 forward, and the traction piston 35 contacts the guide piston 33 to close the communication passage 41, causing the guide piston 33 to move forward and increase the hydraulic pressure. The chamber 42 is reduced, and the hydraulic pressure in the hydraulic pressure chamber 42 is introduced into the front wheel side wheel cylinder W/C (Fr), which is the driving wheel, to brake the driving wheel.

The hydraulic pressure P for braking this driving wheel is controlled by the auxiliary hydraulic pressure source 5.
If the hydraulic pressure at 0 is P, then the wheel cylinder W on the rear wheel side, which is the driven wheel,
No hydraulic pressure is transmitted to /C(Rr).

In addition, in the fail-safe cylinder 20, when the hydraulic pressure of the auxiliary hydraulic pressure source 50 disappears during anti-lost control, the fail-safe piston 21 retreats, the fail-safe valve 24 opens, and the fail-safe cylinder 20 communicates with the input boat 10 of the first cylinder 5. The pressure fluid in the communication port 15 is connected to the fail-safe cylinder 2.
0 reaches the bypass outlet 26 from the input boat 23, the hydraulic pressure is transmitted to the foil cylinder (V/C), and the braking hydraulic pressure is secured.

[Problem that the invention seeks to solve]

In such a hydraulic pressure control device for wheel slip control,
The stepped cylinder 32 constituting the hydraulic pressure control device has a large diameter part and a small diameter part, and the large diameter part has a cylindrical guide piston 3.
The traction piston 35 is slidably fitted into the small diameter portion, and the traction piston 35 is slidably fitted into the small diameter portion.
5 moves toward and away from the end of the guide piston 33, the entire device has to become longer in the axial direction of the stepped cylinder 32, resulting in a problem that the device becomes larger.

In addition, the guide piston 33 and the traction piston 35
If the coaxiality of the two parts is not improved, a gap will be created at the abutting part when the two come into contact. The piston 35 required high-precision machining. Further, since the guide piston 33 and the traction piston 35 are pressed toward the control chamber 43 by respective dedicated springs 34 and 36, the number of parts increases, resulting in high cost.

The present invention has been made in view of the above-mentioned matters, and allows miniaturization, processing accuracy does not need to be so high, and
The technical challenge is to create a hydraulic pressure control device that can be manufactured at low cost.

[Means to solve the problem]

In order to solve the above problems, the present invention has the following configuration.

That is, a guide piston 81 that is slidable within the cylinder 77 and an inner piston 86 that is slidable within the guide piston 81 are provided, and one end of both pistons 81 and 86 is connected to a mask ring (M/C) and a foil cylinder (W). /C), and the other end selectively faces a control chamber 88 connected to the auxiliary hydraulic pressure source 50, and the cylinder 77
Hydraulic pressure control is performed by configuring so that the communication between the master cylinder (M/C) and the foil cylinder (W/C) is cut off by the engagement of the fixed valve seat 78 provided at the end of the guide piston 81 with one end of the guide piston 81. It was used as a device.

〔Example〕

FIG. 1 shows a hydraulic pressure control device according to a first embodiment of the present invention, which is used in the hydraulic pressure control device for wheel slip control described in the section [Prior Art] above.

A stepped cylinder 75 is provided which includes a small diameter part 76 and a large diameter part 77 and has a fixed valve seat 78 between them.
A plug 79 is fitted into a larger-diameter plug fitting portion following 7, and is fixed with a set screw 80 to seal the stepped cylinder 75 liquid-tightly. A guide piston 81 is slidably provided within the large diameter portion 77 and is slidable from a position where it abuts the plug 79 to a position where it abuts the fixed valve seat 78.

Further, a recess 82 is formed on one side of the guide piston 81 facing the small diameter portion 76 of the stepped piston, and a cylindrical protrusion 83 is protruded from the other side of the guide piston 81.
A communication hole 8 in this cylindrical projection 83 that communicates with the recess 82
4 is formed. Also, the cylindrical protrusion 83 has a through hole 8.
5 is drilled.

An inner piston 86 (corresponding to the traction piston 35) is slidably fitted into the recess 82 of the guide piston 81.

In addition, a master cylinder (M/C) and a foil cylinder (
A hydraulic pressure chamber 87 is formed next to the W/C), and an auxiliary hydraulic pressure source 5 is formed in the useful cylinder 75 on the other side of the guide piston 81.
A control chamber 88 is formed which selectively connects to the accumulator P as zero. One end of the guide piston 81 and the inner piston 86 is connected to a master cylinder (M/
C) and the hydraulic chamber 8 connected to the foil cylinder (W/C)
7, and the other end is connected to a control room 88.

A spring 89 is provided in the hydraulic chamber 87 and stretched between the cylinder wall surface and the inner piston 86 to urge the inner piston 86 and the guide piston 81 toward the control chamber 88 side.

In addition, with the guide piston 81 moving to the right in the figure, the stepped cylinder 75 between the guide piston 81 and the fixed valve seat 78 is connected to a human powered boat 90 following a mask'n ring (M/C) and a driven wheel. A first output boat 91 following a wheel cylinder (W/C) of a certain rear wheel is provided, and further,
A second output boat 92 is provided in the small diameter portion 76 of the stepped cylinder 75, which is connected to the curved wheel cylinder (C) which is the drive wheel.

Next, a case where the hydraulic pressure control device having the above configuration is used as a component of the device shown in FIG. 4 to perform traction control will be described.

When a slip occurs between the driving wheels and the road surface during acceleration or starting, the on-off valve 71 is closed and the on-off valve 66 is opened in response to a command from an electronic control device (not shown), and the pressure fluid in the accumulator is used to control the stepped cylinder 75. It is introduced into the chamber 88, moves the guide piston 81 and the inner piston 86 forward, and the guide piston 81 comes into contact with the fixed valve seat 78, causing the mask ring (M/C) to connect with the boil cylinder (W/C) on the front wheel side. Communication is cut off. Thereafter, the inner piston 86 moves to the left in the figure by the auxiliary hydraulic pressure from the through hole 85 and the communication hole 84 to reduce the volume of the hydraulic chamber 87, so that the hydraulic pressure in the hydraulic chamber 87 is reduced to the driving wheel. The front wheel cylinder W/C (P
r) via the second output boat 92 to brake the drive wheels.

In this case, when the guide piston 81 comes into contact with the fixed valve seat 78 and the first output boat 91 is cut off, the hydraulic pressure chamber 87 and the rear wheel side wheel cylinder (W/C) are cut off. Therefore, the wheel cylinder W/C on the rear wheel side which is the driven wheel
The hydraulic pressure generated in the hydraulic pressure chamber 87 is not transmitted to (Rr).

FIG. 2 shows a hydraulic pressure control device according to a second embodiment of the present invention, and the same parts as in FIG. 1 are denoted by the same reference numerals.

In this embodiment, the guide piston 81 is cylindrical, and the inner diameter from one end to the other end is a slate, making it the same as the inner diameter of the recess 82 in the first embodiment. Therefore, if the inner piston 86 is made to have the same shape as the first embodiment, the inner piston 86 pushed by the spring 89 will move inside the guide piston 81 until it comes into contact with the plug 79, and the auxiliary hydraulic pressure from the accumulator P will be reduced. Since the inner piston 86 cannot be moved again to the left in the figure, a hook portion 86a that locks onto the guide piston 81 is provided at the edge of one end surface of the inner piston 86, and this hook portion 8
6a prevents the inner piston 86 from moving to the right in the figure. The other structures and operations are the same as those in the first embodiment, so their explanations will be omitted.

In addition, in each of the examples described above, the device was used as a device to prevent slippage of the drive wheels during acceleration or starting, but it was also used as an anti-lock control device to reduce the wheel cylinder fluid pressure by changing the volume of the fluid pressure chamber. - Anti-lock control may be performed by applying pressure.

〔Effect of the invention〕

In the present invention, the guide piston 81 and the inner piston 8
Precision is not required for coaxiality with 6, and only one spring is required. Therefore, there is no need to increase machining accuracy, the size can be reduced, and manufacturing can be done at low cost.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of the first embodiment of the present invention, FIG. 2 is a sectional view of the second embodiment of the invention, FIG. 3 is a sectional view of a conventional device, and FIG. FIG. 3 is a hydraulic circuit diagram of a hydraulic pressure control device for wheel slip control using the device. (M/C)...Master cylinder, (W/C)...Wheel cylinder, P...Liquid pressure source, 77 (75)...Large diameter part of cylinder (stepped cylinder), 81...Guide piston, 8
6. Inner piston, 87. Hydraulic pressure chamber, 88. Control room. Patent applicant: Akebono Brake Industry Co., Ltd. Figure 3 Figure 4

Claims (1)

[Claims] (1) Guide piston 81 that can slide within the cylinder 77
and an inner piston 86 that is slidable within the guide piston 81, one end of both pistons 81, 86 facing a hydraulic chamber 87 connected to the master cylinder (M/C) and the foil cylinder (W/C), and , the other end selectively faces a control chamber 88 connected to the auxiliary hydraulic pressure source 50, and the master cylinder (M/C ) and a foil cylinder (W/C).