JPH032446Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a pressure accumulator used in an anti-skid hydraulic pressure control system for a vehicle.

[Background of the idea]

Conventionally, various anti-skid systems and devices have been proposed in order to prevent problems associated with the occurrence of wheel lock during braking of an automobile, such as the locked wheels sliding on the road surface. These anti-skid technologies are broadly divided into electric circuit mechanisms for detecting the occurrence of wheel lock conditions based on changes in wheel rotational speed, or in addition to this, detecting the release of lock conditions; The system is basically a combination of hydraulic pressure control devices that directly control brake hydraulic pressure such as depressurization and repressurization based on signals from such electric circuits.

Such hydraulic pressure control devices include various valves (electromagnetic valves, differential pressure operated valves, etc.) that open and close the communication state of paths, pressure accumulators, and electromagnetic pumps that pump pressure fluid from the brake device into the pressure accumulator. Although it is
Among these, the pressure accumulator occupies a considerable proportion of the entire device in terms of volume and weight. Because it is necessary to strictly prevent gas from entering the brake fluid, the structure of this pressure accumulator usually uses a metal coil spring or the like instead of using a general gas pressure system.

[Purpose of invention]

From the above-mentioned viewpoints, the present invention was developed with the aim of realizing a lightweight anti-skid hydraulic pressure control device for vehicles by using an elastic rubber material as a pressure accumulating member in a pressure accumulator. .

Another purpose of the present invention is to expand the range of load and spring constant selection by using an elastic rubber material as the pressure accumulating material, and to facilitate the design of pressure accumulators compatible with various anti-skid hydraulic pressure control devices. It's there.

Furthermore, another object of the present invention is to prevent the brake fluid from coming into contact with the elastic rubber body, which is a pressure accumulating material, through the piston-cylinder mechanism in which the sealing member is assembled on the sliding surface. The purpose of the present invention is to provide a pressure accumulator that reduces restrictions on material selection and can be shared by multiple brake fluid pressure systems.

[Summary of the idea]

The gist of the pressure accumulator of the present invention to achieve this purpose is to accumulate pressure fluid from the brake equipment side of the vehicle brake fluid pressure system via a pump in order to reduce the brake pressure during anti-skid control. In the anti-skid hydraulic control device, the pressure fluid in the pressure accumulator can be transferred to the brake device via a solenoid valve. a movable piston; an elastic rubber body that engages with an end of the piston opposite to the inflow chamber in a sliding direction to press the piston toward the inflow chamber; and an elastic rubber body assembled on the outer periphery of the piston. and a sealing member for sealing the inflow chamber from the elastic rubber body.

[Example of idea]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on embodiments shown in the drawings, and the following embodiments are shown as examples in which one pressure accumulator is applied to the entire brake system of a four-wheeled vehicle.

This is because most automobile brake fluid pressure systems have two independent cross-piped brake fluid pressure transmission routes between the left front and right rear wheels, and between the right front and left rear wheels, and the fact that the brake fluid is transferred to the rear wheels. The pressure transmission system is generally equipped with a control valve for reducing hydraulic pressure, such as a proportioning valve. As for the system, it is controlled in such a way that the proportioning valves and the like are in principle locked at the same time.
Based on the premise that if a wheel lock occurs in one of the wheels, there is a high risk that the other wheel will also become locked, and cross piping with a proportioning valve, etc. in the rear wheel path is installed. In this type of vehicle, the hydraulic pressure that controls the depressurization and repressurization of brake fluid is placed upstream of the branch point of the path that transmits hydraulic pressure from the master cylinder to the front and rear wheels (i.e. front right to rear left, and front left to rear right). By installing a control device, we have achieved optimal anti-lock control for the entire vehicle, and the anti-lock mechanism for the entire vehicle is not independent for each of the four wheels, but one for each of the two hydraulic pressure systems. be.

Embodiment 1 In FIG. 1, 1 is a brake pedal, 2 is a tandem master cylinder, 3 _A and 3 _B are paths (pipe lines) for transmitting brake fluid pressure from master cylinder 2, and In the example, there is a feature that these two systems are independent and cross-piped, and the items attached to each of these two systems are indicated by subscripts A and B to distinguish them.

The paths 3 _A and 3 _B are connected to the hydraulic pressure control sections 4 _A and 4 _B , and the paths 5 _A and 5 B from the hydraulic pressure control sections 4 _A and 4 _B are branched in the middle, and one of the branches is connected to the hydraulic pressure control sections 4 A and 4 _B. 5 _AF ,
5 _BF (For the front wheel side, add an additional F to the subscript)
is the brake system for front wheels 6 _AF and 6 _BF (not shown)
At the same time, the other 5 _AR and 5 _BR (additional R is added to the subscript for the rear wheels) are connected to the rear wheels 8 _AR and 8 _BR via the proportioning valves 7 _A and 7 _B.
brake equipment (not shown).

Furthermore, all four wheels are each equipped with a speed sensor (not shown) to detect the state of their rotational speeds, so that an abnormal drop in the wheel rotational speed during braking, that is, a wheel lock can be detected. In addition, in the above, the hydraulic pressure control section _4A ,
4 _B prevents the transmission of pressure fluid from the master cylinder to the brake equipment in response to the occurrence of wheel lock during braking, and releases the fluid pressure on the brake equipment side to a common pressure accumulator outside the system. This controls the hydraulic pressure to be rapidly reduced, and if necessary, the pressurized fluid that has escaped outside the system is pumped up again to the brake equipment side to re-increase the brake fluid pressure.

To explain the hydraulic pressure control section of this example in more detail, the gate valves 9A and 9B connected to the master cylinder 2 side of each system A and B, and the normally open type gate valves _9A and _9B connected to the brake equipment side. First electromagnetic switching valves _10A , _10B ,
The pressure fluid on the brake equipment side is pumped outside the system by pumps _11A , 1
A normally closed second electromagnetic switching valve _13A , 1 for pumping water to a common type pressure accumulator 12 described below via _1B .
_3B , and the discharge pressure liquid from the pressure accumulator 12 is connected to the gate valve _9A or _9B and the first electromagnetic switching valve _10A.
Or, it is provided so as to be supplied to the intermediate liquid chamber _14A or _14B between 10B and _10B . In this example, the second electromagnetic switching valves 13 _A , 13 _B and the pumps 11 _A ,
_11B , small capacity reservoirs _15A and _15B are provided to compensate for the delay in reducing the brake oil pressure. Further, 16 _A and 16 _B are relief valves.

Describing the structure of the gate valves 9 _A and 9 _B here, this is usually set springs 17 _A and 17 _B.
Pathways 3 _A , 3 _B and intermediate liquid chambers 14 _A , 14 _B
Open the space between the intermediate liquid chamber 14 _A and the path 5 _A or 14 _B.
and 5 _B hydraulic pressure is P14 _A > P5 _A or P14 _B > P5
_B , close the intermediate liquid chamber 14 _A or 14 _B to the path 3 _A or 3 _B , and then close the intermediate liquid chamber 14 A or 14 B to the path 5 A or 3 _B.
Or , the circuit continues to be closed until the hydraulic pressure in the intermediate liquid chamber _14A or _14B is restored to the same pressure as that in the intermediate liquid chamber 14A or 14B.

The first electromagnetic switching valves 10 _A and 10 _B are normally open, closed by a brake fluid pressure reduction signal S ₁ , and then opened when a brake fluid pressure repressurization signal S ₂ is input.

The second electromagnetic switching valves _13A and _13B are normally closed, opened by the signal _S1 , and closed by the input of the signal _S2 . These switching valves are opened and closed in such a way that the brake fluid pressure is reduced and re-pressurized to a predetermined level using the signals S ₁ and S ₂ (or the brake fluid pressure holding signal may be used as necessary). controlled by.

In this example, the pumps 11 _A and 11 _B have a cam 18 eccentrically rotated by one electromagnetic motor (not shown), and a plunger 19 _A and 1 common to both systems.
_9B is used as a driving means, thereby reducing the number of parts in the device.

Proportioning valves _7A and _7B are well-known devices for reducing and transmitting brake hydraulic pressure to the rear wheels in accordance with the appropriate brake force distribution ratio for the rear wheels, which is determined by the characteristics of the vehicle. To be applied to this example, one having an appropriate structure and function may be selected from known ones.

Next, the pressure accumulator 12, which has a characteristic configuration of this example, will be explained.

The pressure accumulator 12 of this example has pressure liquid inlet chambers 20 _A and 20 _B into which the pressure liquid of both systems A and B flows, and the pressure accumulation mechanism using the inflow pressure liquid can be realized by using one elastic rubber material 21. This makes it possible to share parts and reduce costs. That is, the cylinder 22 forming the inflow chambers _20A and _20B includes a balance piston 23 and a pressure piston 24.
is accommodated, and this piston 24 is made of elastic rubber material 21
The elasticity of the elastic rubber material 21 is applied via a rigid flat plate 25 that is in contact with the entire end of the piston 24 .
Normally, the balance piston 23 is held at a rest position in which the internal volumes of the inflow chambers 20 _A and 20 _B are minimized.

In this state, if anti-skid control is started for system A, the pump 11 _A causes pressure fluid to flow into the inflow chamber 20 _A of the pressure accumulator 12 from the paths 5 _AF and 5 _AR of system A, and the balance piston 23
slides downward in the figure, compressing the elastic rubber material 21 via the pressing piston 24 and the rigid flat plate 25.
Therefore, pressure is accumulated due to compressive deformation of the elastic rubber material 21, and the first anti-skid control is performed.
By switching the solenoid valve _10A from closed to open, this accumulated pressure fluid is again transmitted to the brake device side of the A system.

Furthermore, when anti-skid control is started for system B, pressure fluid similarly flows into the inflow chamber _20B , the balance piston 23 remains stationary, and the pressure piston 24 slides downward in the figure, and the elastic rubber 21 compression is performed to achieve a predetermined pressure accumulation.

When anti-skid control is performed simultaneously for both systems A and B, the inflow chambers 20 _A and 20 _B
Pressure liquid flows into each of the inflow chambers 20A and 20B, compressing the elastic rubber material 21 by sliding the pressure piston 24, and the balance piston 23 slides between the inlet chambers _20A and _20B to balance the liquid pressure in both chambers. It turns out.

The elastic rubber material 21 used in this example has a thick cylindrical shape with a small diameter through hole in the center, so that the volume change due to axial compression can be escaped at the through hole portion. ing.
Further, the pressure is accumulated by compressing the cylinder in the axial direction, and for this purpose, a rigid flat plate 25 is used so that the compressive load is applied uniformly to the entire surface of the end face. The elastic rubber material is highly heat resistant,
Further, a rubber (including plastic) that can maintain a stable elastic modulus against temperature changes, particularly changes in the low temperature range where anti-skid control is easily performed, is preferably selected, and for example, silicone rubber or the like is often used.

According to the anti-skid hydraulic pressure control device configured as described above, the pressure accumulator, which generally occupies a considerable portion in terms of volume and weight, can be made smaller and lighter, and in particular, compared to the case where metal springs are used. Therefore, the significance of weight reduction is extremely large, and its practical benefits are large.

Embodiment 2 The present embodiment shown in FIG. 2 is the same as the above-described embodiment 1 except that the pressure accumulator 12 is changed, so illustration of the configuration of the other parts except for the pressure accumulator 112 is omitted. In addition, 100 is added to the reference numeral for the same member.

The feature of the pressure accumulator 112 of this example is that the elastic rubber material 121 that accumulates pressure is used in a state of shear deformation. Therefore, the elastic rubber material 121 is a thick-walled cylinder with its axis centered The cross section includes thin rigid cylinders 126 and 127 formed in an arrow shape as shown in the figure, and thin-walled rigid cylinders 126 and 127 are formed on the entire outer and inner peripheral surfaces.
are integrally fixed together, and a pressing piston 124 is engaged with the end of a rigid cylinder 127 on the circumferential surface.

According to such a configuration, the elastic rubber material 121 receives shear force due to the sliding of the pressing piston 121, and accumulates pressure in a state of shear deformation. As a result, it is easier to take design actions when you are sure of the desired performance.

It should be noted that the present invention is not limited to the above-described type of anti-skid, but may be applied, for example, to a case where a hydraulic pressure control device including independent pressure accumulators is used in each of the four wheels.

[Effects of the invention] As mentioned above, the present invention provides a novel pressure accumulator that has not been seen before in anti-skid hydraulic control systems for vehicles, which are in strong demand for being smaller and lighter. In particular, it exhibits extremely excellent effects in terms of weight reduction, ease of design adaptation, etc., and its practical benefits are great.

Furthermore, as explained in the first embodiment, it is possible to adopt a configuration in which the elastic rubber body, which is a pressure accumulating material, does not come into contact with the brake fluid through the piston-cylinder mechanism assembled on the sliding surface. This has the effect that there is no need to consider fluid resistance in the design, and since the brake fluid inflow chamber of the pressure accumulator engages with the elastic rubber body via the piston, multiple systems can be used by providing a balance piston. It also has the excellent effect of being able to be used in common with other brake hydraulic systems, and its practical benefits are enormous.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an outline of the overall configuration of a brake system including an anti-skid hydraulic pressure control device according to a first embodiment of the present invention, and FIG. 2 is a diagram showing a modification of the same pressure accumulator. 1...Brake pedal, 2...Master cylinder, 3, 5...Route, 4...Hydraulic control section, 6...
Front wheel, 7... Proportioning valve, 8...
Rear wheel, 9...gate valve, 10...first solenoid valve, 1
1... Pump, 12... Pressure accumulator, 13... Second solenoid valve, 14... Intermediate liquid chamber, 15... Reservoir, 1
6... Relief valve, 17... Set spring,
18...Eccentric cam, 19...Plunger, 20,
120...Inflow chamber, 21,121...Elastic rubber material, 22,122...Cylinder, 23,123...
...Balance piston, 24,124...Press piston, 25...Rigid flat plate, 126,127...Rigid cylinder.

Claims (1)

[Scope of utility model registration request] Brake device side pressure fluid of vehicle brake hydraulic system,
In the anti-skid hydraulic pressure control device, the hydraulic fluid is pumped into a pressure accumulator via a pump to reduce brake pressure during anti-skid control, and the pressure fluid in the pressure accumulator can be transmitted to the brake device via a solenoid valve. The pressure accumulator includes a piston that is slidable within a cylinder facing an inflow chamber for pressurized liquid, and an end of the piston on the opposite side of the inflow chamber in the sliding direction to engage the piston in the direction of the inflow chamber. 1. A pressure accumulator for use in an anti-skid hydraulic pressure control device, comprising: an elastic rubber body that presses against the piston; and a seal member that is assembled to the outer periphery of the piston and seals the inflow chamber from the elastic rubber body.