JPH0410141Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to an electromagnetic hydraulic pressure control valve that is installed in an anti-skid device of a vehicle hydraulic brake system and that directly or indirectly controls the hydraulic pressure of a brake cylinder. be.

BACKGROUND ART As an anti-skid device for a vehicle hydraulic brake system, for example, as described in Japanese Patent Laid-Open No. 58-224839, there is a regulator that operates the hydraulic pressure of a brake cylinder using hydraulic pressure from another hydraulic pressure source. An indirect control type anti-skid device controlled by
As described in Japanese Patent No. 56-142733, there is a directly controlled anti-skid device in which an electromagnetic hydraulic pressure control valve is provided in a main passage connecting a master cylinder and a brake cylinder.

The electromagnetic hydraulic pressure control valve controls the hydraulic pressure in the hydraulic pressure chamber of the device to be controlled, such as the hydraulic pressure chamber of the regulator in an indirect control type anti-skid device, or the hydraulic pressure chamber of the brake cylinder in a directly controlled anti-skid device. established for the purpose of

One type of electromagnetic hydraulic pressure control valve is a combination of an electromagnetic directional switching valve and an electromagnetic flow control valve. An electromagnetic directional switching valve has two states: one in which the hydraulic chamber of the controlled device is communicated with a hydraulic pressure source such as a master cylinder or a pump, allowing the flow of hydraulic fluid from the hydraulic pressure source into the hydraulic chamber, and the other in which it is communicated with a tank. The hydraulic pressure chamber can be electromagnetically switched to a state that allows the hydraulic fluid to flow from the hydraulic pressure chamber to the tank. In addition, the electromagnetic flow control valve is provided with a non-throttled passage and a throttle passage in parallel, and is provided between the electromagnetic directional switching valve and the hydraulic pressure chamber of the controlled device, so that the hydraulic fluid flows through both the non-throttled passage and the throttle passage. The flow rate of the hydraulic fluid can be switched between a state where the fluid is allowed to flow in parallel and a state where the non-restricted passage is closed and flow is allowed only through the passage, and the flow rate of the hydraulic fluid is switched in two stages, large and small.

By using an electromagnetic hydraulic pressure control valve consisting of a combination of an electromagnetic directional control valve and an electromagnetic flow control valve, it is possible to rapidly increase, gradually increase, or
It can be controlled by a combination of four modes: rapid decrease and gradual decrease, making it easy to maintain the hydraulic pressure within an appropriate range.

Problems to be Solved by the Invention However, in this type of electromagnetic hydraulic pressure control valve, the restricting passage has conventionally been constituted by an orifice, and because the diameter of this orifice is small, foreign matter mixed in the hydraulic fluid can cause problems. There is a problem in that there is a possibility that clogging may occur, and that careful attention must be paid to measures to prevent clogging, such as installing a filter.

Means for Solving the Problems In order to solve this problem, the present invention provides an electromagnetic hydraulic pressure control valve that is a combination of an electromagnetic directional control valve and an electromagnetic flow control valve as described above. This is constructed by filling a porous material into a through hole formed in parallel with a non-restricted passage.

The porous body has a multi-layered structure in which a coarse part is provided on both sides of a fine part, and the through holes are filled so that the working fluid flows in a direction substantially perpendicular to the layers. A multilayered porous body made of a sintered alloy is particularly preferred.

Functions and Effects If the throttle passage is constituted by a porous body having countless fine passages in this way, even if some of the fine passages become clogged, the throttling action of the entire porous body will hardly change. Therefore, the occurrence of a situation in which the normal hydraulic pressure control function of the electromagnetic hydraulic pressure control valve is impaired due to clogging of the throttle passage can be effectively avoided.

Particularly, the effects of the present invention are particularly noticeable in a hydraulic pressure source equipped with an accumulator and a pump that is miniaturized. For example, if the fluid pressure of the fluid pressure source is 100Kg/
cm ² , in order to achieve a gradual pressure increase gradient of 50 Kg/cm ² /sec, it is necessary to set the orifice diameter to about 0.1 mm, which makes it difficult to pressurize the orifice.
While careful attention must be paid to prevent clogging of orifices such as filters, if the present invention is followed, there is no need to process small-diameter orifices, and the measures to prevent clogging are simple. .

In addition, in an embodiment where the porous body has a multilayer structure consisting of fine-mesh parts and coarse-mesh parts, the fine-mesh parts mainly perform the squeezing function and the coarse-mesh parts play the filter function, so Fluctuations in action are better prevented.

Embodiment Hereinafter, an embodiment of the present invention will be described in detail based on the drawings.

In FIG. 1, 10 is a housing of a hydraulic pressure control device. Although this housing is divided into members 12, 14, 16, 18, 20, 22, 24, and 25 etc. for convenience of manufacture, it functions as an integral housing 10 after assembly. This housing 10 is provided with a port 26 connected to a hydraulic pressure source such as a master cylinder or a pump, a port 28 connected to a controlled device such as a brake cylinder or a regulator, and a port 30 connected to a tank. and port 28 is connected to ports 26 and 3.
an electromagnetic directional control valve 32 that selectively communicates with
and an electromagnetic flow control valve 34 that switches the flow rate of the hydraulic fluid flowing in and out of the port 28 in two stages, large and small.

The electromagnetic directional switching valve 32 includes a plunger 40 to which balls 36 and 38 as valve elements are fixed at both ends. The balls 36 and 38 are opposed to valve seats 42 and 44 formed in the housing 10, respectively, and the plunger 40 is urged toward the valve seat 42 by a compression coil spring 46. Thus, while ball 36 would normally seat on valve seat 42 and close passageway 48 leading to port 30;
Ball 38 separates from valve seat 44 to open a fluid passageway 50 leading to port 26 .
The liquid passage 5 passes through the plunger chamber 52 and the communication port 54.
It is connected to 6.

The plunger 40 is held by a hollow piston 60 made of a magnetic material, and the piston 60 is fitted into a piston chamber 61 of the housing 10 so as to be slidable in the axial direction. A solenoid (first solenoid) 64 wound around a resin bobbin 62 is concentrically disposed on the outer circumferential side of the piston 60, and when this solenoid 64 is excited, the piston 60 moves as shown in FIG. is sucked downward, the plunger 40 is moved against the biasing force of the spring 46, the ball 36 is separated from the valve seat 42, and the ball 38 is seated on the valve seat 44. That is, by energizing the solenoid 64, the electromagnetic directional switching valve 32 is switched from a state in which the liquid passage 56 is communicated with the port 26 to a state in which it is communicated with the port 30.

The electromagnetic flow control valve 34 also includes a plunger 72 to which a ball 70 as a valve element is fixed, a piston 74 holding the plunger 72, and a plunger 72.
It includes a compression coil spring 78 that biases the valve away from the valve seat 76, a solenoid (second solenoid) 82 wound around a bobbin 80, and the like. A piston chamber 84 in which the piston 74 is accommodated is communicated with the liquid passage 56, while the throttle passage 86
and a liquid passage 88, and further communicated with the port 28 through a liquid passage (non-throttled passage) 90 formed in parallel with the throttle passage 86 and having a larger diameter. The valve seat 76 is formed at the opening of the liquid passage 90.

The ball 70 is normally kept away from the valve seat 76 by the biasing force of a spring 78.
Therefore, the hydraulic fluid flowing from the liquid passage 56 side to the liquid passage 88 side can flow in both the throttle passage 86 and the liquid passage 90 in parallel, but the solenoid 82 is energized and the piston 74 is in the first position. In the case of upward suction in the figure, the ball 70 seats on the valve seat 76 and closes the liquid passage 90, so that the hydraulic fluid flows exclusively through the throttle passage 86.

The throttle passage 86 is connected to a liquid passage 90 in the housing 10.
A sintered piece 92 is press-fitted into a through hole formed in parallel with the sintered piece 92 . The sintered piece 92 is made of metal,
It is a porous body made of sintered powder such as ceramics, and can be thought of as an aggregate of countless microscopic passages. Therefore, it not only has the same throttling function as a conventional orifice, but even if some of the countless microscopic passages become clogged, the throttling action will hardly change, and the specified throttling function will be maintained over a long period of time. can be maintained.

FIG. 2 shows an application example of the electromagnetic hydraulic pressure control valve configured as described above. In this example, an electromagnetic directional switching valve 32 and an electromagnetic flow control valve 34, which constitute an electromagnetic hydraulic pressure control valve, are provided in a main fluid passage 104 that connects a master cylinder 100 and a brake cylinder 102. The main liquid passage 104 is further provided with a check valve 106, and this check valve 1
A bypass passage 108 is provided to bypass the electromagnetic directional control valve 32 and the electromagnetic flow control valve 34.
10 is provided in the opposite direction to the check valve 106.

A reservoir 112 is connected to the electromagnetic directional switching valve 32 , and a pump 114 pumps up working fluid from the reservoir 112 and stores it in an accumulator 116 . That is, in this example, the master cylinder 100, the pump 114, the accumulator 116, etc. constitute the hydraulic pressure source, and the brake cylinder 10
2 constitutes a device to be controlled by hydraulic pressure, and the reservoir 112 constitutes a tank, forming a directly controlled anti-skid device.

The electromagnetic directional control valve 32 and the electromagnetic flow control valve 34 are normally in the state shown in FIG. Therefore, the brake fluid pressure-fed from the master cylinder 100 in response to the brake operation is supplied to the brake cylinder 102 through the check valve 106 in the main fluid passage 104, the electromagnetic directional control valve 32, and the electromagnetic flow control valve 34. . At this time, the electromagnetic flow control valve 34 is in a state in which the ball 70 is separated from the valve seat 76 and the liquid passage 90 is opened in FIG. 1, so the hydraulic fluid can flow to the brake cylinder 102 at a sufficient flow rate.
Delay in brake effectiveness is effectively avoided. Also,
Most of the hydraulic fluid flows to the brake cylinder 102 through the fluid passage 90, and the amount of hydraulic fluid flowing through the throttle passage 86 is very small, so even if foreign matter is mixed in the hydraulic fluid, the sintered piece 92 There is a very small chance that the container will become clogged with foreign matter. Furthermore, even if foreign matter should become clogged, the throttling action of the sintered piece 92 will hardly change as described above, thereby increasing the reliability of the electromagnetic flow control valve 34, that is, the reliability of the entire electromagnetic hydraulic pressure control valve including it. Improves sex.

When the hydraulic pressure of the hydraulic fluid supplied to the brake cylinder 102 is low in relation to the friction coefficient of the road surface, the anti-skid device does not operate, and both the electromagnetic directional control valve 32 and the electromagnetic flow control valve 34 are in the state shown in FIG. will be kept as is. and. When the brake operation is released, the hydraulic fluid in the brake cylinder 102 flows through the bypass passage 108 to the master cylinder 100.
Reflux to.

On the other hand, if the hydraulic pressure supplied to the brake cylinder 102 is too high in relation to the coefficient of friction of the road surface, the slip rate of the wheels increases, so a controller (not shown) detects this fact based on a signal from a sensor (not shown). Detection and electromagnetic directional control valve 32
is switched to connect the brake cylinder 102 to the reservoir 112. As a result, the hydraulic fluid flows out from the brake cylinder 102 toward the reservoir 112, and the hydraulic pressure in the hydraulic pressure chamber of the brake cylinder 102 is reduced. At this time, if the controller determines that it is necessary to rapidly reduce the hydraulic pressure in the brake cylinder 102, the solenoid 82 of the electromagnetic flow control valve 34 is kept in a demagnetized state, and the hydraulic fluid is sufficiently supplied through the liquid passage 90. It flows out to the reservoir 112 at a flow rate of 1. In this case, only a small amount of the working fluid passes through the sintered piece 92. Further, when the controller determines that it is necessary to gradually reduce the hydraulic pressure in the brake cylinder 102, the solenoid 82 is energized, the electromagnetic flow control valve 34 is switched, and the hydraulic fluid is gradually transferred to the reservoir via the throttle passage 86. 112.

The brake fluid that has flowed into the reservoir 112 is pumped up by the pump 114 and
It can be stored in 16. Therefore, if the wheel slip rate becomes smaller than the appropriate range as a result of reducing the hydraulic pressure in the hydraulic pressure chamber of the brake cylinder 102 as described above, the controller controls the solenoid of the electromagnetic directional valve 32. 64, the high pressure hydraulic fluid stored in the accumulator 116 will flow into the brake cylinder 102. At this time, if it is necessary to rapidly increase the hydraulic pressure in the brake cylinder 102, the solenoid 82 of the electromagnetic flow control valve 34 is demagnetized, and the hydraulic fluid passes through the liquid passage 90 and reaches the brake cylinder 102 at a sufficient flow rate.
and conversely to brake cylinder 1.
If it is necessary to gradually increase the hydraulic pressure of 02, the solenoid 82 is energized, the liquid passage 90 is closed, and the hydraulic fluid is allowed to flow into the brake cylinder 102 little by little through the throttle passage 86.

FIG. 3 shows yet another application example of the electromagnetic hydraulic pressure control valve according to the present invention. In this example, the hydraulic pressure in the hydraulic pressure chamber of the brake cylinder 102 is indirectly controlled by using the hydraulic fluid pumped up from the tank 120 by the pump 122 and supplied to other hydraulically operated devices such as the power steering device 124. This is an indirectly controlled anti-skid device. Electromagnetic directional valve 32
An electromagnetic hydraulic pressure control valve consisting of an electromagnetic flow control valve 34 is provided between the first regulator 126 and the second regulator 128. The hydraulic pressure in the power hydraulic pressure chamber 130 of the regulator 128 is controlled.

The first regulator 126 has a pressure regulating piston 1 fitted in a housing 132 in a fluid-tight and slidable manner.
34, and a power hydraulic pressure chamber 136 and a brake hydraulic pressure chamber 138 are formed on both sides of the pressure regulating piston 134. The pressure receiving surface of the pressure regulating piston 134 on the power hydraulic pressure chamber 136 side is the brake hydraulic pressure chamber 138.
The hydraulic pressure of the master cylinder 100 is guided to the brake hydraulic pressure chamber 138, so the power hydraulic pressure chamber 136 has a lower hydraulic pressure than that of the master cylinder 100, and the hydraulic pressure of the master cylinder 100 is lower than that of the master cylinder 100. As the pressure increases, an increasing power hydraulic pressure will be generated. This power hydraulic pressure is guided to the power hydraulic chamber 130 of the second regulator 128 via the electromagnetic hydraulic pressure control valve according to the present invention, and is also guided to the power hydraulic chamber 142 of the bypass valve 140.

The master cylinder 100 is connected to the brake cylinder 102 by a main fluid passage 104 as in the application example shown in FIG.
28 are provided. Second regulator 128
The pressure regulating piston 146 is disposed in a housing 144 in a fluid-tight and slidable manner. The pressure regulating piston 146 operates by receiving the hydraulic pressure of the power hydraulic pressure chamber 130 on one pressure receiving surface and the hydraulic pressure of the brake hydraulic pressure chamber 148 on the other pressure receiving surface.
0, ball 152, compression coil spring 154
The hydraulic pressure in the brake hydraulic pressure chamber 148 is controlled based on the hydraulic pressure in the power hydraulic pressure chamber 130 by opening and closing a cut valve 156 consisting of a brake hydraulic pressure chamber 156 and increasing and decreasing the volume of the brake hydraulic pressure chamber 148.

Further, the bypass valve 140 is connected to the power hydraulic pressure chamber 14.
Piston 1 as long as power hydraulic pressure is applied to 2.
58 compresses the ball 160 with the coil spring 16
The valve is seated on the valve seat 164 against the urging force of the second regulator 128, and the hydraulic pressure controlled by the second regulator 128 is applied to the brake cylinder 102, but in the unlikely event that power hydraulic pressure is not obtained. If the ball 160 is damaged, the ball 160 is seated on the valve seat 166 by the biasing force of the spring 162, and the hydraulic fluid from the master cylinder 100 is transferred to the second regulator 12.
8 and is allowed to flow to the brake cylinder 102.

In this example, the electromagnetic hydraulic control valve consisting of the electromagnetic directional switching valve 32 and the electromagnetic flow control valve 34 has a hydraulic pressure source consisting of the pump 122 and the first regulator 126, and the second regulator 12 which is the device to be controlled.
The excitation and demagnetization of the solenoids 64 and 82 are appropriately controlled by a controller that detects the slip rate of the wheels based on the sensor signal. The hydraulic pressure in the power hydraulic pressure chamber 130 of the regulator 128 is controlled, and the second regulator 128 controls the hydraulic pressure in the brake hydraulic pressure chamber 148 based on the hydraulic pressure in the power hydraulic pressure chamber 130. The hydraulic pressure of the cylinder 102 is controlled.

Also in this example, when the anti-skid device is in the non-operating state, the liquid passage 90 is kept open, so that the hydraulic fluid enters and exits the power hydraulic pressure chamber 130 mainly through this liquid passage 90. Since the amount of hydraulic fluid passing through the passage 86 is extremely small, even if foreign matter gets mixed into the hydraulic fluid, there is a very low possibility that it will clog the sintered piece 92. Moreover, since the throttling action of the sintered piece 92 hardly changes, the reliability of the electromagnetic flow control valve and, by extension, the electromagnetic hydraulic pressure control valve as a whole can be improved.

Although one embodiment of the present invention and its two typical application examples have been described above, the present invention can also be implemented in other embodiments.
For example, as shown in FIG. 4, the sintered piece for forming the throttle passage can be a multilayered sintered piece 170 in which a fine-mesh part 168 and coarse-mesh parts 169 are provided on both sides. and the sintered piece 170
is attached to the electromagnetic flow control valve so that the hydraulic fluid flows in a direction approximately perpendicular to the layers of the multilayer structure. In this case, the fine-mesh part 168 mainly performs the aperture function, but the coarse-mesh part 169 performs a filter function to prevent clogging of the fine-mesh part 168. Fluctuations in the throttling action of the piece 170 can be more reliably prevented.

The porous body can also be made of synthetic resin, and the porous body manufactured separately from the housing of the electromagnetic flow control valve can not only be fixed to the housing, but also be fixed in the through hole formed in the housing. It is also possible to directly form a porous body. In short, it is sufficient that the porous body is filled in the through holes as a result.

Furthermore, in the embodiment, the flow control valve 3
4 is normally used to keep the non-throttled passage open to reduce the amount of working fluid passing through the throttle passage, which effectively prevents clogging of the porous body itself. However, it is also possible to apply the present invention to an electromagnetic hydraulic pressure control valve equipped with an electromagnetic flow control valve that keeps the non-throttled passage closed at all times, and the porous body may become clogged to some extent. In this case, the effects of the present invention are even more pronounced, since the aperture effect does not change in this case.

It goes without saying that the present invention can be implemented with various modifications and improvements based on the knowledge of those skilled in the art.

[Brief explanation of drawings]

FIG. 1 is a front sectional view of an electromagnetic hydraulic pressure control valve according to an embodiment of the present invention. FIGS. 2 and 3 are system diagrams showing different application examples of the electromagnetic hydraulic pressure control valve. FIG. 4 is a sectional view conceptually showing the internal structure of a sintered piece used in another embodiment of the present invention. 10... Housing, {32... Electromagnetic directional control valve, 34... Electromagnetic flow control valve} (electromagnetic hydraulic pressure control valve), 36, 38... Ball, 40... Plunger, 42, 44... Valve seat, 46... Compression coil spring, 60... Piston, 64... Solenoid (first solenoid), 70... Ball, 72...
... Plunger, 74 ... Piston, 76 ... Valve seat, 78 ... Compression coil spring, 82 ... Solenoid (second solenoid), 86 ... Throttle passage,
90...Liquid passage (non-throttled passage), 92...Sintered piece,
100... Master cylinder, 102... Brake cylinder, 112... Reservoir, 114... Pump, 120... Tank, 122... Pump, 12
6...First regulator, 128...Second regulator, 130...Power hydraulic chamber, 168...Fine part, 169...Coarse part, 170
...Sintered piece.

Claims (1)

[Claims for Utility Model Registration] (1) An electromagnetic directional control valve that selectively communicates the hydraulic chamber of a controlled device such as a brake cylinder with a hydraulic pressure source and a tank, and a throttle passage and a non-throttle passage in parallel. an electromagnetic flow control valve that is provided between the electromagnetic directional switching valve and the hydraulic pressure chamber and controls the flow rate of the hydraulic fluid in two stages, large and small, by opening and closing the non-restricted passage; An electromagnetic hydraulic pressure control valve that is installed in an anti-skid device of a hydraulic brake device and that rapidly increases, rapidly decreases, gradually increases, or gradually decreases the hydraulic pressure in the hydraulic pressure chamber according to changes in the slip rate of the wheels, wherein the non-restricted passage and An electromagnetic hydraulic pressure control valve for an anti-skid device, characterized in that the throttle passage is formed by filling the through holes formed in parallel with a porous material. (2) The porous body has a multilayer structure in which a coarse part is provided on both sides of a fine part, and the through hole is filled so that the working fluid flows in a direction substantially perpendicular to the layer. An electromagnetic hydraulic pressure control valve for an anti-skid device according to claim 1, which is a registered utility model. (3) The electromagnetic hydraulic pressure control valve for an anti-skid device according to claim 1 or 2, wherein the porous body is a sintered alloy.