JPS60121161A - Gate valve for vehicle antilock system - Google Patents

Abstract

PURPOSE:To prevent a pedal from kick-back by operating a gate valve for normally maintaining a main path to transmit braking oil pressure under the opened condition so as to interrupt communication between the master cylinder side and the downstream side of the gate valve in antilock control. CONSTITUTION:Normally a gate valve 5 maintains always a main path input system 81 under the opened condition to smooth the transmission and return of pressurized oil and securely carry out braking operation. Also, in antiskid control, a first valve 6 is closed and a second valve 10 is opened so that brake oil in a main path output system 82 pressure is reduced. And differential pressure produced and acting on a balance piston 20 in the gate valve 5 moves the piston 20 right so that a ball 28 abuts against a valve seat 25 and input and output oil chambers Ai, Ao in the gate valve 5 are insulated from each other. Thus, pressurized oil pumped by a pump 12 through a bypass path 9 is not transmitted to the master cylinder side so that kick-back on a pedal is not produced.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a wheel anti-lock system, and more particularly, to a gate for use in an anti-lock system that eliminates a sudden drop in wheel speed, that is, wheel lock, which may occur during vehicle braking by reducing brake hydraulic pressure. It concerns valves.

Recently, various types of wheel anti-lock technologies have been proposed to improve safety during vehicle braking, and typical examples include mask cylinders (hydraulic generators) and A normally open shutoff valve is placed in the brake hydraulic pressure transmission path (hereinafter referred to as the main path) that connects the brake equipment, and is normally open and closed when it is necessary to lower the brake hydraulic pressure. For this purpose, a bypass-connected path (hereinafter referred to as a bypass path) is provided, and this bypass path and the brake equipment side output system of the main path are separated by a pressure reducing valve that is normally closed, and the brake hydraulic pressure is Brake pressure oil flowing into the bypass passage through the normally closed pressure reducing valve that opens when lowering is required is stored in a reservoir mechanism that stores the brake pressure oil while decreasing the oil pressure by increasing the chamber volume in response to pressure, for example, Furthermore, the oil stored in the reservoir mechanism is pumped up to the main path by a pressure oil return mechanism including a pump, and the opening/closing operation of the shutoff valve (normally open type) and pressure reducing valve (normally closed type) is controlled by the vehicle. A system has been proposed in which an electronic control circuit detects wheel lock during braking.

If we consider the control state of the wheel brake hydraulic pressure by such a wheel anti-lock device, this means that in order to prevent the brake force from becoming excessive, the shutoff valve is initially closed and the brake hydraulic pressure is prevented from increasing further. If the drop in wheel speed is still not resolved, the brake force is reduced by opening the pressure reducing valve and releasing the brake oil pressure to the reservoir mechanism, and when the wheel speed is restored by reducing the brake oil pressure, Control is performed by pumping up pressure oil from a reservoir to restore brake oil pressure.

By the way, in an anti-lock system as typified by the above example, the main path for transmitting brake hydraulic pressure is divided into an input system path and an output system path by a normally open shutoff valve. Pumping up the pressure oil in the brake equipment (i.e. the pressure oil in the output path) at
Since this is applied to the mask cylinder side (that is, the input path side), the oil pressure fluctuation within the mask cylinder increases, causing a problem called kickback to the brake pedal that is linked to the mask cylinder. be. This kickback is actually perceived by the driver as a fairly large pedal movement, and firstly, it occurs in an oscillatory manner within an extremely small amount of time. Second
Furthermore, since anti-lock control is generally rarely performed, this poses a serious problem in that it may cause panic among inexperienced drivers.

Therefore, in order to avoid this kind of kickback phenomenon, there have been some efforts in the past. It has also been proposed to install a check valve that only allows the flow of pressure oil.

However, in such a system, a separate path is naturally required to return the hydraulic pressure when the brake is released from the brake device (hereinafter referred to as W in some cases) side to the mask cylinder (hereinafter referred to as IV in some cases) side. At the same time, this hydraulic pressure return path reliably blocks the flow of pressure oil of 1vC-+■9 in the opposite direction, and must not leave any residual pressure inside the brake system to prevent dragging when the brake is released. Since this is essential, there are great difficulties in designing the entire system or in terms of processing accuracy.

The present invention has been made in view of these points, and its first purpose is to maintain the main path for transmitting brake hydraulic pressure in an open state at all times, and to prevent the aforementioned kickback of the brake pedal during anti-lock control. In order to prevent this, it is an object of the present invention to provide a gate valve that hydraulically separates the mask cylinder Y side from the downstream side where the oil pressure decreases and increases.

A second object of the present invention is to mechanically and simply disconnect the hydraulic interlocking relationship by the gate valve by utilizing the hydraulic pressure difference that occurs between the two sections partitioned within the main path. The reason is that we made it possible to

Therefore, the gist of the present invention to achieve such an object is that in the first invention of the present application, a brake cylinder is provided in the middle of the main path for transmitting brake hydraulic pressure from the mask cylinder to the brake device. a normally open type first box that divides the main path into an input system and an output system, and magnetically closes the main path when the brake hydraulic pressure drops during vehicle braking, and an output system of the main path. Pressure oil that pumps the pressure oil of the output system to the input system in response to the magnetic opening of the normally closed second valve connected to the input system by γI and interposed in the middle. In a vehicle anti-lock system equipped with a bypass path including a return mechanism, a gate valve is provided at a position upstream of the bypass path connection part of the main path input system, the gate valve being a human power system upstream of the gate valve. A balance piston that receives oil pressure Pi and the output system oil pressure Po at both ends and moves only when Pl>Po, and is operatively connected to this balance piston so that when the balance piston moves, it always follows the path of the main path input system. A gate valve used in a vehicle anti-lock system is characterized by having a shutoff valve mechanism that switches from an open state to a closed state.

Another feature of the second invention of the present application is that, in the gate valve, the valve body of the shutoff valve mechanism is integrated with the balance piston.

The present invention will be explained in detail below based on the drawings.

Embodiment 1 In FIG. 1, 1 is a brake pedal, 2 is a mask cylinder, 3 is a piston connected to the brake pedal 1, and 4 is a reservoir.

The main path 8 for transmitting brake hydraulic pressure from the mask cylinder 2 is connected to the brake device 7 via a normally open gate valve 5 and a first valve 6 along the way. The upstream side (mask cylinder side) of the valve 6 forms an input system 8I, and in particular, the space between the output oil chamber A0 of the gate valve 5 and the first valve 6 forms an intermediate oil chamber 8I. Also, the first valve 6 of the main path
The downstream side (111C brake device side) constitutes an output system 82.

Further, a bypass passage 9 is connected between the output system 82 of the main passage 8 and the intermediate oil chamber 82 (in the illustrated example, the output oil chamber A of the gate valve 6). , a normally closed second valve 10 facing the main path output system 8□, a small capacity glue reservoir 11, an electromagnetic pump 12, an accumulator 13, and a check valve 14 are sequentially provided. When pressure oil flows into the intermediate oil chamber 11, the pressure oil is pumped up into the accumulator 13 by a pump, and returned to the intermediate oil chamber 8 through the check valve 14.

In the above configuration, the first valve 6 and the second valve 10 are provided as electromagnetic switching valves, and the former first valve receives a signal S output from an anti-skid control circuit (not shown) (i.e., stops the increase in brake oil pressure or A signal that commands brake oil pressure maintenance) causes a switching operation from open to close.
The latter second valve is configured to cause a switching operation from close to open in response to a signal S2 instructing a decrease in brake oil pressure.

Note that the reservoir mechanism 11 and the electromagnetic pump 12 may be of known types, as long as the electromagnetic pump 12 operates to pump water in synchronization with the switching of the second valve 10 from closed to open. Specifically, an eccentric cam may be used. 15 is rotated by a motor (not shown), and the plunger 16 reciprocates to pump up pressure oil in one direction.

With the above configuration, the increase and decrease of the brake oil pressure is controlled normally because the gate valve 5 and the first valve 6 are normally open and the second valve 10 is normally closed. The hydraulic pressure is directly transmitted to the brake device 7, and returns directly to the mask cylinder 2 when the brake is released. Also, during anti-skid control, the first valve 6
, and the second valve 10 closes and then opens, the pressure oil in the brake device 7 is transferred from the bypass path 9 to the intermediate oil chamber 8. ', and then the second valve 10 is returned from open to closed, and the first valve 6 is opened and closed appropriately to raise or maintain the brake oil pressure again.

The feature of this example is that the gate valve 5 can suitably function in controlling the brake oil pressure during the above-mentioned normal state and anti-skid control. That is, gate valve 5
Under normal conditions, the main path input system 8 is always maintained in an open state to ensure smooth transmission and return of pressure oil, and during anti-skid control, the main path input system 8 is always maintained in an open state. and output system 8
In response to the generation of differential pressure between 8.2 and 8.2, the intermediate oil chamber 8. ' is separated from the master cylinder 2 side in terms of pressure, so that the effects of pressure changes such as a drop or rise in brake oil pressure are not transmitted to the mask cylinder at all.

The structure of the gate valve 5 in this example has a balance piston housing chamber 18 and a shutoff valve housing chamber 19 in the body 17,
By the movement of the balance piston 20 in the former chamber, the shutoff valve in the latter chamber can be switched from a normally open state to a closed state, and thereby the input oil chamber At connected to the mask cylinder side in the gate valve and the first valve 6 Output oil chamber Ao connected to the side
It has a structure that allows it to be opened and closed.

To describe this in more detail, a balance piston 20 is accommodated in the balance piston housing chamber 17 so as to be movable in the axial direction, one of its two ends faces the gate valve input oil chamber At communicating with the master cylinder, and the other end faces the gate valve input oil chamber At communicating with the master cylinder. It faces a control oil chamber Ac that communicates with the brake device 7. 21 is a seal ring n that liquid-tightly seals the oil chambers At and Ac.
A lightly loaded set spring 22 is engaged with this balance piston 20, and is biased to a limit position on the input oil chamber Ai side. In this example, the balance piston 20 has a built-in IJ-F valve 23 that allows only the flow of pressure oil from the oil chamber Ac to the oil chamber Ai, but this valve 23 is designed to prevent the flow of pressure oil from the oil chamber Ac to the oil chamber Ai. This is to ensure smooth return of oil.

Next, regarding the shutoff valve in the gate valve 5, the shutoff valve housing chamber 19 in this example is the gate valve output oil chamber A.

The output oil chamber A of this passage 24 is connected to the input oil chamber Ai through a small diameter passage 24. The opening to forms the valve seat 25. The ball 27 is pressed against the valve seat 25 by the hold spring 26 to constitute a shutoff valve, and the balance piston 20 passes through the passage 24 to the output oil chamber A. By protruding the locking rod 28, the ball 27 is normally separated from the valve seat 25.

To describe the operation of a gate valve having a balance piston and a shutoff valve configured as described above, during non-braking and energized braking, the force acting on the balance piston in both axial directions is equal to the spring force of the set spring 22 due to the input oil. Room Ai
Therefore, the balance piston 20 is biased to the limit position on the side of the input oil chamber Ai, and the shutoff valve in the gate valve maintains the normally open state shown in the figure.

On the other hand, during anti-skid control, the main path output system 8. is shut off from the intermediate oil chamber 81, and the main path output system 8
When the brake oil pressure inside □ is lowered, the force in both axial directions acting on the balance piston 20 inside the gate valve 5 is equal to the oil pressure A.
i, Ac is Pi)Pc, so the control oil chamber A
As the balance piston 20 increases in the direction c, the balance piston 20 moves from the rest position toward the oil chamber Ac (rightward in the figure). Therefore, the locking rod 28 that separates the ball 27 from the valve seat 25 also moves together with the lance piston 20,
The ball 28 comes into contact with the valve seat 25, and the inside of the gate valve 5 is closed.
The output oil chambers At and AO will be shut off.

Due to this shutoff, the intermediate oil chamber is pressure-isolated from the master cylinder side by the gate valve 5, and the pressure oil pumped up through the no-pull path 9 is not transmitted to the mask cylinder side, which prevents the phenomenon of kick bank in the brake pedal. This means that this will not occur.

Note that the shutoff by the shutoff valve in the gate valve is performed by opening the first valve 6 and the main path output system 8. The hydraulic pressure of the balance piston 20 increases and the hydraulic action on the balance piston 20 continues until it returns to the normal state, and is then released. However, if the brake pedal is released before that, the IJ IJ-) valve 23
The pressure oil then returns to the master cylinder side.

As described above, the gate valve in this embodiment can open and close the appropriate path during anti-skid control and normal braking in the middle of the path in the brake hydraulic pressure transmission system. The opening and closing of the path is achieved by mechanical movement based on hydraulic action, and the structure is simple, so the benefits are significant.

Embodiment 2 In this embodiment shown in FIG. 2, the valve body 127 of the cutoff valve in the gate valve is integrated with the balance piston 120,
Therefore, the second embodiment is the same as the first embodiment except that the hold spring 126 is not required. Therefore, the same members are shown with 10.0 added to their reference numerals and their explanations are omitted.

The function of the gate valve in this example is roughly the same as in the first embodiment, but in this example, the balance piston 120 and the valve body 127 of the shutoff valve are integrated, so that when the balance piston 120 moves, the valve body 127 is forcibly brought into contact with the valve seat 125 to shut off the input and output oil chambers At and Ao, so that in addition to the first embodiment, the following effects can be obtained. In other words, in the structure of the first embodiment The shutoff valve prevents pressure oil from flowing from the intermediate oil chamber toward the mask cylinder, but allows pressure oil to flow in the opposite direction. Therefore, when the first valve 6 is closed, the intermediate oil chamber is closed to the main path outlet valve system 8. If the hydraulic pressure value in the intermediate oil chamber is lower than the hydraulic pressure value on the mask cylinder side in a state where the oil pressure is cut off from the mask cylinder side, the pressure oil will flow from the mask cylinder side to the intermediate oil pressure chamber. It is inevitable that it will flow into the exit room. This means that during anti-skid control, if the necessary force of 1 is applied to ensure the flow of pressure oil back to the intermediate oil chamber via the inflow path, the pressure will be accumulated in the accumulator 13. This means that it must be set better than on the mask cylinder side.

Otherwise, check the check valve <lube 1 for the intermediate oil chamber.
This is because the pressure oil is supplied not through the valve 4 but through the shutoff valve.

On the other hand, in the second embodiment, the shutoff valve uses a valve body 127 integrated with the balance piston 120 to shut off the valve in a strong one-slope manner based on the oil pressure difference between the input system 8 and the output system 82 of the main path. Therefore, in this cut-off state, pressure oil is supplied to the intermediate oil chamber only from the accumulator 113 via the check loop 114.
The pressure accumulation setting value of 13 can be considered not to be directly related to the hydraulic pressure value generated on the mask cylinder side, and in practical terms, compared to the case of Embodiment 1, in Example 2, the pressure accumulation setting value of the accumulator jiil is set to 70. There is no difference at all even if it is about % I navy blue.

Such a reduction in the pressure accumulation setting value is extremely beneficial in the design of accumulators, which are generally easy to increase in size, and in the case of the configuration of Example 2, the volume in which the anti-lock device of this building is installed is limited. This has the effect of greatly increasing applicability to vehicles.

As described above, the gate valve used in the vehicle anti-lock system according to the present invention can improve safety, facilitate device design, and further downsize accumulators etc. in the practical application of this type of system. It is effective in terms of aiming, and its practical benefits are worth it.

[Brief explanation of the drawing]

Figure 1 is a ready-made drawing of Embodiment 1 of an anti-lock system to which the gate valve of the present invention is applied, and Figure 2 is Embodiment 2 of the same.
FIG. 1.101... Brake pedal 2.102... Master cylinder 3.103... Piston 4.104... Reservoir 5-1105... Gate valve 6.106... First valve 7.1 ()7... Brake device 81, 108. ...Main path input system 8+', 1081'...Intermediate oil chamber 9.109...Bypass path 10.110...Second
Valve 11.111... Reservoir 12.112... Electromagnetic pump 13.113... Accumulator 14.114... Check pulp 15.115... Eccentric cam 16.116... Plunger 17.117 ...Body 18.118...Balance piston housing chamber 19.11
9...Shutoff valve accommodation chamber 20.120...Balance piston 21.121...Seal ring 22.122...Set spring ring 23, 123...Relief valve 24.
124... Passage 25. 125... Valve seat 26... Hold spring 27... Ball 127... Valve body 28... Locking rod.

Claims (1)

[Claims] 1. A system that is interposed in the middle of the main path for transmitting brake hydraulic pressure from the master cylinder to the brake device and divides the main path into a human power system and an output system, and that lowers the brake hydraulic pressure during vehicle braking. a normally open first valve that electromagnetically closes the main path at times;
Pressure oil return that pumps pressure oil from the output system to the input system in response to electromagnetic opening of a normally closed second valve connected from the output system to the input system in the main path and interposed in the middle. In a vehicle anti-lock system including a mechanism, a gate valve disposed at an upstream side (4) of the main path input system from the /C path connection A balance piston receives the input system hydraulic pressure Pi upstream of the gate valve and the output system hydraulic pressure P at both ends and moves only at the time of Pi), and the balance piston is operatively connected to the lance piston. A gate valve used in a vehicle anti-lock system, comprising a shutoff valve mechanism that switches the path of the main path input system from a normally open state to a closed state when the main path input system moves. 2. Brake hydraulic pressure transmission from a master cylinder to a brake device. a normally open type first valve that is interposed in the middle of a main path for use, divides the main path into an input system and an output system, and electromagnetically closes the main path when it is necessary to lower the brake oil pressure during vehicle braking. and,
Pressure oil that pumps pressure oil from the output system to the input system in response to electromagnetic opening of a normally closed second valve connected from the output system to the input system in the main path and interposed in the middle. In a vehicle anti-lock system equipped with a bypass path including a return mechanism, the gate valve is provided at a position upstream of the bypass path connection part of the main path input system, and the input system upstream of the gate valve hydraulic pressure Pi and the output system hydraulic pressure P. a balance piston that receives at both ends and moves only when Pi)Po, and a valve body integrated with the balance piston, which is separated from the valve seat when the balance piston is normally stationary and moves from the main path input 1. A gate valve for use in a vehicle anti-lock system, comprising a shutoff valve mechanism that opens a path in the system and closes the path when two valve bodies abut against a valve seat when a balance piston moves.