JPH0565386B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an anti-lock device, in particular:
In an automobile brake system, a signal from a wheel speed detector is sent to an electronic information processing device to detect a wheel lock state. The present invention relates to a device that reduces the amount of hydraulic fluid flowing into a brake device, thereby reducing brake pressure regardless of whether the brake is depressed, and suppressing and controlling braking force by regulating the pressure.

Conventional technology Conventionally, for this type of anti-lock device,
Various proposals have been made, for example,
In the method disclosed in Publication No. 28307, a normally open inlet valve is interposed in the main flow path that communicates the pressurization source (master cylinder) activated by the operation of the brake pedal and the wheel cylinder of the brake device, while the wheel cylinder Normally closed discharge valves are provided in the discharge passages communicating between the brake fluid storage tank and the brake hydraulic fluid storage tank, and both the introduction valve and the discharge valve are electrically operated based on commands from the electronic information processing device. There is. In this device, when the anti-lock is not activated, power is not supplied to either the inlet valve or the discharge valve, and the hydraulic fluid flows into the wheel cylinder according to the amount of depression of the brake pedal.
That is, when reducing the brake fluid pressure, power is supplied to the introduction valve and the discharge valve so that the introduction valve is closed and the discharge valve is opened to discharge the working fluid from the wheel cylinder side into the storage tank. There is. In addition, when pressurizing the brake fluid pressure again, the inlet valve is opened and the discharge valve is closed when it is not energized, and when the brake fluid pressure is maintained at a constant pressure, power is supplied only to the inlet valve and the valve is closed. With the discharge valve in the closed position, the brake fluid pressure is kept constant. In this way, this device can control in three modes: pressure reduction, pressure increase, and constant pressure maintenance, but it is possible to control the valves operated by power supply in two modes.
In other words, it requires an inlet valve and an outlet valve, which has the disadvantage of increasing the cost due to an increase in the number of parts and the labor required for installation.

Japanese Patent Application No. 112440/1983 has proposed an anti-lock device that eliminates the above drawbacks and simplifies the configuration by requiring only one solenoid valve, but this device has a configuration that is inappropriate for practical use. doing. When the above device is put to practical use, the configuration is shown in FIG. A 3-port, 2-position switching flow control valve 5 which is actuated by pressure and requires excitation is provided.
An electromagnetic discharge valve 7 that can switch between two port positions will be provided. In this device, the non-energized flow control valve 5
In combination with the electromagnetic discharge valve 7, anti-lock control is performed using two modes of pressure reduction and pressure control only. The structure of the flow control valve 5 is as shown in the figure, an inner cylinder 11 inserted into a cylinder block 10.
The spool 12 is urged by the return spring 4 and fitted into the inner cylinder 1 so as to be slidable in the axial direction.
1, an inlet 13 through which the hydraulic fluid flows from the master cylinder, a first outlet 14 through which the hydraulic fluid flows out to the wheel cylinder, and a second outlet 15 through which the hydraulic fluid flows out to the hydraulic fluid storage tank via the discharge valve 7. The structure is such that it is provided in a direction perpendicular to this direction.

The electromagnetically operated discharge valve 7 has a liquid passage 61 in the center communicating with the second outlet 15, a stator 63 having an electromagnetic coil 62 on its exterior, and a frame 64 surrounding the electromagnetic coil 62 to form a magnetic path. , a non-magnetic guide ring 65 whose one end on the inner diameter side is press-fitted into the stator 63 in a liquid-tight manner and the other end on the outer diameter side is press-fitted into the frame 64 in a liquid-tight manner, and is urged in a direction away from the stator 63 by a spring 66; A liquid passage that forms a discharge path in the center of an armature 67 that is slidably housed on the inner periphery of a thin walled portion of the guide ring 65, is attracted to the stator 63 when power is supplied to the electromagnetic coil 62, and is movable against the biasing force of a spring 66. A fixed valve seat 68 is press-fitted into the frame 64, and a fixed valve seat 68 is integrally press-fitted into the armature 67.
It has a movable valve body 69 that can cut off communication with the
A movable valve body 69 exists on the second outlet 15 side of the discharge liquid path 6 with the fixed valve seat 68 as a boundary.

Problems to be Solved by the Invention In the flow control valve shown in FIG. 3 described above, it is necessary to close the open end of the inner cylinder 11 formed in the cylinder block 10 with an end plug 16,
Even if the electromagnetic discharge valve 7 is arranged in a direction perpendicular to the axial direction of the flow control valve 5, or even if it is arranged in series with the flow control valve 5, the second outlet needs to be arranged orthogonally to the spool 12. Therefore, the end plug 16 is required in either case. Therefore, there are disadvantages in that the cost increases due to the increase in the number of parts, and the required space increases.

Furthermore, since the structure is such that a small flow of liquid is generated in the return spring chamber 17 of the inner cylinder 11 only during flow rate control when the electromagnetic discharge valve 7 is actuated with electricity, it is easy to bleed air into the return spring chamber 17. There is a problem that cannot be solved. Therefore, if air (bubbles) remains in the return spring chamber 17,
When the pressure at the inlet 13 increases, the bubbles collapse, causing the spool 12 to move to the anti-lock operating position, making sudden pressurization impossible, and the presence of the bubbles impairs the responsiveness of the spool 12 operation, so to speak. The drawback was that the brakes did not respond well to the amount of pressure applied to the brake pedal.

Furthermore, it is necessary to bleed air from the brake piping system during the vehicle assembly process, but the common method is to evacuate the brake piping system from the master cylinder's reserve tank to a vacuum pump, and then pump the brake fluid. (commonly called vacuum filling). On the other hand, each component of the brake system is usually filled with brake fluid and leaks.
After carrying out performance tests, it is transferred to the vehicle assembly process, and therefore, in order to complete the evacuation of the brake piping system within a certain working time during vacuum filling, the residual brake fluid in each component of the brake system must be removed. It is necessary to keep the amount constant. (If there is a large amount of residual gas, the degree of vacuum attainment will decrease due to defoaming.) However,
As mentioned above, the movable valve body 69 of the discharge valve 7 is attached to the fixed valve seat 6.
8, the hydraulic pressure during normal braking (non-antilock control) is present in the return spring chamber 17 as well as in the valve chamber 70 where the liquid passage 61, armature 67, and movable valve body 69 are present. The brake fluid in these parts must be drained after the performance test is completed.
This is not easy because the valve chamber 70 is a dead end in the closed state shown in the figure. (It is desirable that the brake fluid in the pump circuit between the discharge valve 72 of the pump 71 and the fixed valve seat 68 remains.) Also, since the brake pressure normally acts on the guide ring 65, there is a gap between the stator 63 and the frame 64. It is also necessary to ensure liquid tightness between the parts, and although this is sometimes achieved by rolling or other methods, this increases space and costs.

Means for Solving the Problems In order to solve the above problems, the present invention provides an anti-lock device having the following configuration. Therefore, the present invention provides a discharge passage provided to branch from a main passage communicating a pressure source and a wheel brake, and a valve provided in this discharge passage, which is opened by electromagnetic force by power supply when the pressure of the anti-lock is reduced. a normally closed discharge valve that communicates with the discharge passage and allows hydraulic fluid from the wheel brake to pass through and be discharged to the discharge passage; an inlet provided at the branch point and communicating with the pressurization source; and the wheel brake. a first outlet communicating with the discharge valve; a second outlet communicating with the discharge valve;
A hollow cylindrical inner cylinder having three outlet ports, and a spool that is slidably fitted into the inner cylinder, has a liquid passage including an orifice, and can switch the communication state of each of the ports. and a return spring that biases the spool in one direction, and when the antilock is inactive, the spool is in the inactive position and the inlet and the first outlet are connected through a large flow path, and when the antilock is depressurized, By opening the discharge valve and discharging the hydraulic fluid from the second outlet to the discharge passage, the spool moves against the biasing force of the return spring due to the biasing force due to the differential pressure generated at both ends of the spool, and the second When the first outlet and the second outlet are communicated to discharge the hydraulic fluid of the wheel brake to the discharge path, and the discharge valve is de-energized when the anti-lock is pressurized, the flow of the hydraulic fluid from the second outlet to the discharge valve is stopped. However, when the liquid pressure at the inlet is higher than the liquid pressure at the first output, a small flow path is formed from the inlet to the first outlet through the orifice, and a small flow path is formed through which a small flow of liquid flows. When the pressure difference becomes less than this pressure difference, the spool returns to the non-operating position by the biasing force of a return spring and communicates with the large flow path; a flow rate switching valve configured to accommodate the flow rate switching valve; An anti-lock device having a housing having a cylinder hole, wherein one open end of the inner cylinder is configured to be the second outlet, and the second outlet side open end is connected to the open end of the cylinder hole. The flow rate switching valve is housed in the cylinder hole so as to be located at the second outlet side, and the discharge valve is brought into contact with the second outlet side opening end of the inner cylinder to close the cylinder hole, and the return spring is housed in the second outlet side. The present invention provides an anti-lock device characterized in that it is disposed in a return spring chamber provided facing an outlet.

Further, the present invention provides: a discharge passage provided to branch from a main passage communicating a pressurization source and a wheel brake; and a fixed valve seat provided in the discharge passage and having a liquid passage constituting the discharge passage. a movable valve body that can open and close this liquid passage by coming into contact with and away from the fixed valve seat; an armature that can move the movable valve body by electromagnetic force; A stator that faces the armature and attracts the armature using electromagnetic force when power is supplied; and a stator that urges the armature away from the stator, and when it is not energized, the movable valve body contacts the fixed valve seat to close the liquid passage. a normally closed discharge valve having a spring that presses the valve and which can be opened by electromagnetic force when supplied with electricity to communicate the discharge passage; an inlet provided at the branch point and communicating with the pressurizing source; and an inlet communicating with the wheel brake. a first outlet communicating with the discharge valve; a second outlet communicating with the discharge valve;
a hollow cylindrical inner cylinder having three outlet ports; a spool that is slidably fitted into the inner cylinder and has a liquid passageway including an orifice, and the communication state of each port can be switched; It has a return spring that biases this spool in one direction, and when the antilock is not activated, the spool is in the inactive position and the inlet and the first outlet are connected through a large flow path, and when the antilock is depressurized, the discharge valve is opened. By activating the valve and discharging the hydraulic fluid from the second outlet to the discharge path, the spool moves against the biasing force of the return spring due to the biasing force due to the differential pressure generated at both ends of the spool, and the first and second outlets When the outlet is connected to allow the wheel brake hydraulic fluid to be discharged to the discharge path, and the discharge valve is de-energized when the anti-lock is pressurized, the flow of the hydraulic fluid from the second outlet to the discharge valve is stopped, and the hydraulic fluid from the inlet is de-energized. When the liquid pressure is higher than the liquid pressure at the first outlet, a small flow path is formed through which a small flow passes from the inlet to the first outlet through the orifice, and the liquid pressure difference between the inlet and the first outlet is less than this differential pressure. and a flow rate switching valve configured such that the spool returns to the non-operating position by the biasing force of a return spring and communicates with the large flow path. in series with the exit, and
The movable valve body and the armature are arranged so as to be present in the discharge passage on the opposite side of the side communicating with the second outlet with the fixed valve seat as a boundary, and the movable valve body and the fixed valve seat are sealed when the discharge valve is not energized. The structure is such that the biasing force of the spring in the discharge valve acts on the movable valve body against the force of hydraulic pressure at the second outlet acting on the effective diameter, and the return spring is connected between the second outlet and the discharge valve. The present invention provides an anti-lock device characterized in that the anti-lock device is disposed in a return spring chamber interposed between the two.

Function As mentioned above, in this device, the open end of the cylinder hole that houses the flow rate control switching valve is closed with a discharge valve made of a solenoid valve, so the end plug that is conventionally required can be eliminated. In addition, since the open end of the inner cylinder serves as the second outlet, the return spring chamber in the inner cylinder can be used as a depressurizing flow path through which a large flow rate passes, making it easy to bleed air from the return spring chamber. You can definitely do it.

In addition, since the movable valve body of the discharge valve is configured to exist in the discharge passage on the opposite side of the second outlet with the fixed valve seat as a boundary, the valve chamber containing the armature, movable valve body, and guide ring is normally affected by brake fluid pressure. This not only eliminates the need to drain the brake fluid from the valve chamber for vacuum filling, but also eliminates the need to ensure fluid tightness between the guide ring and stator under high fluid pressure between the frame. The present invention has a unique effect, and other effects will become clear from the description of the embodiments.

Embodiments Hereinafter, the present invention will be explained in detail with reference to embodiments shown in the drawings.

A brake system equipped with an anti-lock device according to the present invention is almost the same as the conventional example shown in FIG. A discharge passage 24 branches from the main passage 22, and a non-excited flow control switching valve 25 and an electromagnetically operated discharge valve 26 are installed at the branch position. They are installed in series and in combination within one cylinder block 27. The discharge passage 24 is connected to a known plunger pump 2 via a hydraulic fluid storage tank 28.
9, the plunger pump 29 communicates with the master cylinder 21 via a reflux passage 30, and pumps up the working fluid discharged into the discharge passage 24 to the master cylinder 21 side by the plunger pump 29. .

In this embodiment, the so-called reflux type structure as described above is exemplified in the configuration after the discharge flow path 24, but
The hydraulic fluid storage tank 28 is shared with the storage tank of the master cylinder, and the pressure fluid pumped up by the pump is introduced into the hydraulic pressure booster via the pressure accumulator, and is removed from the circuit between the master cylinder and the wheel brakes through the discharge flow path. The structure may be such that replenishment of the liquid is carried out by introducing liquid whose pressure has been regulated by a hydraulic pressure booster into the circuit.

Alternatively, it may be a so-called full power type pressurization source that does not have a master cylinder. In short, the present invention can be used in combination with any pressure source structure and any structure after the discharge flow path.

To explain in detail the structure of the flow rate control switching valve 25 and the discharge valve 26 provided at the branch point between the main flow path 22 and the discharge flow path 24, one cylinder block 27
A cylinder hole 31 is bored inside the cylinder hole 31.
The sleeve 32 of the flow control switching valve 25 is fitted and fixed therein, and a discharge valve 26 made of a solenoid valve is installed so as to close the open side of the cylinder hole 31. Although this sleeve 32 is provided in order to realize the above-mentioned inner cylinder advantageously in terms of processing, it is also possible to provide the inner cylinder directly on the cylinder block 27. The sleeve 32 is open at both ends, and one end thereof is fixed to the bottom surface of the cylinder hole 31, while the other end is connected and fixed to the frame 33 of the discharge valve 26. A hydraulic fluid inlet 34 communicating with the main flow path 22 on the master cylinder 21 side is formed between the outer circumferential surface of the sleeve 32 and the inner circumferential surface of the hole 31, and a first hydraulic fluid outlet communicating with the brake device 23 side. 35, and the opening axis portion on the side connected to the frame 33 serves as a second outlet 36 for the hydraulic fluid that linearly communicates with the discharge valve 26 side. Also, sleeve 3
2 is provided with a first introduction passage 37 and a second introduction passage 38 which communicate with the inlet 34 and which penetrate in the radial direction, and an outlet passage 39 which communicates with the first outlet 35 and which penetrates in the radial direction. , and a groove 40 is formed by cutting out the inner surface at a position close to the second outlet 36. A spool 41 is fitted into the sleeve 32 so as to be slidable in the axial direction.
A first liquid passageway 42 is formed to penetrate through the axial center of the liquid passageway 42 , and an orifice 43 is formed at the tip of the liquid passageway 42 on the second outlet 36 side. Also, on the bottom side of the spool 41, the first
A radial second liquid passage 44 that selectively communicates with the introduction passage 37 is bored perpendicular to the first liquid passage 42 . Further, on the outer circumferential surface of the spool 41, a third fluid passage 45 which is elongated in the axial direction is formed which constantly communicates with the above-mentioned outlet passage 39 and selectively communicates with the second introduction passage 38.

The tip of the spool 41 where the orifice 43 is formed is formed as a spring receiver 46, and the sleeve 3
A return spring 49 is compressed between a spring receiver 48 fixed to the inner surface of the liquid passage 47 of the frame 33 that communicates with the second outlet 36 of the second outlet 36 of the frame 33. A filter 50 is attached to the spring receiver 48, and the liquid passageway 4 passes through a return spring chamber 51 surrounded by the sleeve 32, spool 41, and frame 33.
Dust collection is being carried out from the hydraulic fluid flowing out.

As shown in the figure, the frame 33 of the discharge valve 26 is installed to close the open end side of the hole 31.
The liquid passageway 47 that communicates with the second outlet 36 on the same axis is formed at the inner end of the axis thereof, and the fixed valve seat 54 is fixed to the liquid passageway 47. It is opened and closed by a movable valve body 56, which will be described later. In this way, the second outlet 36 formed at the axially open end of the sleeve 32 of the flow control switching valve 25 is arranged in series in the same direction as the discharge valve 26, and the working fluid is directly supplied from the second outlet 36 to the discharge valve 26. I try to be guided in a straight line.

The frame 33 of the discharge valve 26 is formed with a large-diameter valve chamber 52 in its axial portion that communicates with a liquid passage 47 that communicates with the second outlet 36. A discharge passageway 53 is formed which communicates with the above. While the fixed valve seat 54 is attached to the liquid passageway 47, an armature 55 is fitted into the valve chamber 52 so as to be slidable in the axial direction.
The fixed valve seat 54 is opened and closed by a movable valve body 56 fixed to the movable valve body 56 . A stator 58 is incorporated into the frame 33 at a position facing the armature 55, and a coil 58 is installed at the outer circumferential position of the stator 58.
9 is installed, and when power is supplied, the coil 59 is energized to operate the armature 55 and the movable valve body 56 in the direction of the arrow, thereby opening the valve seat 54. Also,
A spring 60 is compressed between the armature 55 and the stator 58, and when not energized, the spring 60 biases the movable valve body 56 to close the valve seat 54. Further, a guide ring 64 is provided on the outer periphery of the armature 55 and has a thin outer periphery portion pressed into the inner diameter side of the frame 33 and a thick inner periphery portion 63 press-fitted into the outer diameter portion of the tip of the stator 58. I'm guiding you. The movable valve body 56 and the armature 55 can be made integrally,
It is also possible to create them separately and provide a slight alignment function between them.

In the figure, reference numeral 61 is an O-ring, which is used to seal each part to prevent liquid leakage.

The hydraulic fluid storage tank 28 that is connected to the discharge flow path 24 and the plunger pump 29 that circulates the hydraulic fluid to the master cylinder 21 have known configurations, and therefore their description will be omitted.

Next, the braking action provided with the anti-lock device having the above structure will be explained.

When the anti-lock is not engaged during normal operation, the large flow path is formed as shown in Fig. 2, and the discharge valve 26 of the solenoid valve
Since the coil 59 is not energized, the movable valve body 56 closes the valve seat 54. That is, the second outlet 36 of the flow control switching valve 25 is in a closed state. In the non-antilock state, the spool 41 is biased by the return spring 49 and is at the upper end position in the figure, and the second introduction path 38 of the sleeve 32, which is constantly in communication with the hydraulic fluid inlet 34, is connected to the spool 41.
It communicates with a third liquid passageway 45 on the outer periphery of. The third
The liquid passage 45 communicates with the first outlet 35 via the outlet passage 39 of the sleeve 32 . Therefore, the inlet 34 of the flow control switching valve 25 communicates only with the first outlet 35, and the master cylinder 21 and the wheel brakes 23 communicate with each other. At that time, the flow rate control switching valve 25
As described above, a large flow path is formed between the inlet 34 and the first outlet 35, through which a large flow of the working fluid passes without passing through the orifice or the like. Therefore, the brake can be controlled by supplying hydraulic fluid to the brake 23 from the main channel 22 in accordance with the amount of depression of the brake pedal 20.

In the non-antilock state, the inlet 34 communicates with the second outlet 36 via the first introduction passage 37, the second liquid passage 44, the first liquid passage 42, and the return spring chamber 51; Since the valve seat 54 on the communicating discharge valve 26 side is closed, the hydraulic fluid is not discharged from the second outlet 36, and therefore the valve chamber 5
Normal brake fluid pressure does not work on 2.

On the other hand, when a wheel speed detector or the like (not shown) detects the occurrence of excessive slip or its signs and establishes an anti-lock state, the coil 59 of the electromagnetic discharge valve 26 is supplied with power and energized. Therefore, the armature 55 descends in the figure, and the movable valve body 5
6 descends against the spring 60 to open the valve seat 54, allowing flow to flow from the second outlet 36 of the flow rate control switching valve 25. Therefore, the working fluid that has flowed into the return spring chamber 51 from the inlet 34, the first introduction path 37, the second liquid passage 44, and the first liquid passage 42 via the orifice 34 flows out from the second outlet 36 and is discharged. It passes through the valve seat 54 of the valve 26, passes through the valve chamber 52, and the discharge passage 53, and is discharged to the discharge passage 24.

During the above operation, as shown in FIG. 2, the differential pressure generated before and after the orifice 43 acts on both ends of the spool 41, and the spool 41 moves against the urging force of the return spring 49 (downward in the figure). do.
Therefore, the communication between the second introduction path 38 and the third liquid passage 45, which communicate with the working fluid inlet 34, is cut off, and the large flow path that communicates the inlet 34 and the first outlet 35 is closed. .

When the spool 41 reaches the position shown in FIG. 2 due to the above operation, the first introduction passage 37 and the second introduction passage 38 communicating with the hydraulic fluid inlet 34 are both blocked by the spool 41, and the first and second introduction passages 37 and 38 communicate with the hydraulic fluid inlet 34. It does not communicate with any of the outlets 36. On the other hand, when the first outlet 35 is in this position, the first outlet 35 is connected to the outlet path 39, the third liquid passage 45, the groove 40, and the return spring chamber 51.
It communicates with the second outlet 36 via. Therefore, the hydraulic fluid in the vehicle brake 23 passes from the first outlet 35 to the second outlet 36, and the discharge valve 2 is opened by power supply.
A reduced pressure channel is formed through which the discharge channel 6 is discharged to the discharge channel 24 . That is, the hydraulic fluid on the wheel brake side is discharged, the brake pressure is reduced, and the wheels are anti-locked.

Moreover, when the communication between the first introduction path 37 and the second liquid passage 44 is cut off, the first introduction passage 37, the second liquid passage 44,
The flow rate passing through the orifice 43 through the first fluid passage 42 becomes zero, and the differential pressure across the orifice 43 begins to decrease. Then, the spool 41 is again moved upward in the drawing by the biasing force of the return spring 49. Then, the first introduction path 37 and the second liquid passage path 44 are brought into communication again, and the orifice 43 is connected again.
The flow rate passing through is ensured, and a pressure difference is generated before and after the
It again overcomes the biasing force of the return spring 49 and descends to the illustrated position. In other words, at the illustrated position, the inner diameter side edge of the first introduction passage 37 and the second liquid passage passage 4 are connected to each other.
4, a differential pressure equal to the biasing force of the return spring 49 divided by the effective diameter of the seal between the outer diameter of the spool 41 and the inside of the sleeve 32 is generated.
occurs before and after the orifice 4 based on this differential pressure.
3 through the inlet 34, the first introduction path 37, the second liquid passage 44, the first liquid passage 42, and the orifice 4.
3. The fluid passes through the spring chamber 51 and is discharged to the discharge passage 24 through the second outlet 36 together with the amount of fluid from the wheel brakes that has passed through the first outlet.

When the exhaust valve 26 is de-energized when the anti-lock is pressurized, the movable valve body 56 is urged by the spring 60 and moves to close the valve seat 54 and close the exhaust valve 26. Therefore, discharge of the hydraulic fluid from the second outlet 36 of the flow rate control switching valve 25 is stopped.

However, in this state, the pressure in the spring chamber 51 connected to the first outlet 35 is lower than the pressure in the inlet 34, so the inlet 34, the first introduction path 37, the second liquid passage 44, the first liquid passage 42, Orifice chair 4
3. The hydraulic fluid that has flowed in via the spring chamber 51 is guided to the wheel brake 23 via the discharge groove 40, the outlet path 39, and the first outlet 35. Therefore, as shown in FIG. 2, the spool 41 is located at the same position as in the reduced pressure state in FIG. 2 and performs the metering action, guiding the same small flow rate to the wheel brake 23 through the small flow paths in the above order. . When the pressure difference between the inlet 34 and the first outlet 35 becomes equal to or less than the above-mentioned differential pressure, the spool 41 is raised in the figure by the biasing force of the return spring 49, and as shown in FIG.
The liquid passageway 45 returns to the non-operating position where it communicates with the second introduction passageway 38, and the large flow passageway is brought into communication.

In the present invention, by having the above configuration,
Return spring chamber 51 of flow rate control switching valve 25
If air is present in the return spring chamber 51, the return spring chamber 51 moves from the first outlet 35 to the second outlet 3 at the time of anti-lock (when the discharge valve is opened by power supply).
The return spring chamber 51 is included in the reduced pressure flow path through which the working fluid flows, and the reduced pressure flow path has a large flow rate without an orifice, so air in the return spring chamber 51 can be completely and easily vented. I can do it.

In addition, since the valve chamber 52 is structured so that brake fluid pressure does not normally act on it, the fluid sealing structure of the guide ring 64 can be easily completed, and the discharge flow path from the second outlet 36 to the fixed valve seat 54 can be easily constructed. The small volume makes it easy to drain the brake fluid.

Effects of the Invention As is clear from the above explanation, the present invention provides (a) a discharge passage provided so as to branch off from a main passage communicating a pressurization source and a wheel brake, and (b) a discharge passage provided in this discharge passage. (c) a normally closed discharge valve that can be opened by electromagnetic force when supplied with electricity to communicate the discharge path; (c) provided at the branch point; A hollow cylindrical inner cylinder having three ports, a first outlet and a second outlet communicating with the discharge valve, and a liquid passageway that is slidably fitted into the inner cylinder and includes an orifice. , a spool that can switch the communication state of each port, and a return spring that biases this spool in one direction, and when the anti-lock is not activated, the spool is in the non-operating position and the inlet and first outlet are connected. When the anti-lock pressure is reduced, the discharge valve is opened and the hydraulic fluid is discharged from the second outlet to the discharge passage, and the return spring is The spool moves against the biasing force, connects the first outlet and the second outlet, and discharges the hydraulic fluid of the wheel brake to the discharge path, and when the discharge valve is de-energized when the anti-lock is pressurized, the second When the flow of hydraulic fluid from the outlet to the discharge valve is stopped and the hydraulic pressure at the inlet is higher than the hydraulic pressure at the first outlet, a small stream is formed from the inlet, passes through the orifice, and heads toward the first outlet, with a small flow rate. When a passage is formed and the liquid pressure difference between the inlet and the first outlet becomes equal to or less than this differential pressure, the spool returns to the non-operating position by the biasing force of a return spring and communicates with the large flow passage. (d) an anti-lock device having a housing having a cylinder hole with one end open for housing the flow rate switching valve, wherein one open end of the inner cylinder is configured to serve as the second outlet; The flow rate switching valve is accommodated in the cylinder hole such that the second outlet side open end is located on the open side of the cylinder hole, and the discharge valve is brought into contact with the second outlet side open end of the inner cylinder. and the movable valve body and armature of the discharge valve are arranged so as to be located in the discharge passage on the side opposite to the side communicating with the second outlet with the fixed valve seat as the boundary. The structure is such that the biasing force of the spring acts on the movable valve body against the force exerted by the hydraulic pressure of the second outlet that acts on the seal effective diameter of the movable valve body and the fixed valve seat when the discharge valve is not energized. Therefore, it has the following effects. That is, the open end of the inner cylinder of the flow rate control switching valve is configured as the second outlet, and the open end of the inner cylinder is closed with a discharge valve made of a solenoid valve, which is not necessary in the past. This makes it possible to eliminate the need for end plugs.

Further, since the return spring chamber in the inner cylinder of the flow rate control switching valve is a depressurizing flow path through which a large flow rate passes, air can be easily and reliably removed from the return spring chamber.

[Brief explanation of the drawing]

Fig. 1 is a partially sectional overall configuration diagram showing an embodiment of the present invention, Figs. FIG. 20... Brake pedal, 21... Master cylinder, 22... Main flow path, 23... Wheel brake, 24...
Discharge channel, 25... Channel control switching valve, 26... Discharge valve, 27... Housing, 31... Hole, 32... Inner cylinder, 34...
Entrance, 35...first exit, 36...second exit, 41...
Spool, 42, 44, 45...liquid passage, 43...orifice, 49...return spring, 51...return spring chamber, 54...fixed valve seat, 55...armature, 56...movable valve body, 58...stator, 59...coil , 60...Spring.

Claims (1)

[Scope of Claims] 1. A discharge section provided so as to branch from the main flow path that communicates the pressure source and the wheel brake; a normally closed discharge valve that communicates with the discharge passage and allows hydraulic fluid from the wheel brake to pass through and be discharged to the discharge passage; an inlet provided at the branch point and communicating with the pressurization source; and the wheel brake. a first outlet communicating with the discharge valve; a second outlet communicating with the discharge valve;
A hollow cylindrical inner cylinder having three outlet ports, and a spool that is slidably fitted into the inner cylinder, has a liquid passage including an orifice, and can switch the communication state of each of the ports. and a return spring that biases the spool in one direction, and when the antilock is inactive, the spool is in the inactive position and the inlet and the first outlet are connected through a large flow path, and when the antilock is depressurized, By opening the discharge valve and discharging the hydraulic fluid from the second outlet to the discharge passage, the spool moves against the biasing force of the return spring due to the biasing force due to the differential pressure generated at both ends of the spool, and the second When the first outlet and the second outlet are communicated to discharge the hydraulic fluid of the wheel brake to the discharge path, and the discharge valve is de-energized when the anti-lock is pressurized, the flow of the hydraulic fluid from the second outlet to the discharge valve is stopped. However, when the liquid pressure at the inlet is higher than the liquid pressure at the first outlet, a small flow path is formed from the inlet to the first outlet through the orifice, and a small flow path is formed through which the liquid flows at the inlet and the first outlet. When the pressure difference becomes less than this pressure difference, the spool returns to the non-operating position by the biasing force of a return spring and communicates with the large flow path; a flow rate switching valve configured to accommodate the flow rate switching valve; An anti-lock device having a housing having a cylinder hole, wherein one open end of the inner cylinder is configured to be the second outlet, and the second outlet side open end is connected to the open end of the cylinder hole. The flow rate switching valve is housed in the cylinder hole so as to be located at the second outlet side, and the discharge valve is brought into contact with the second outlet side opening end of the inner cylinder to close the cylinder hole, and the return spring is housed in the second outlet side. An anti-lock device characterized in that it is placed in a return spring chamber facing the outlet. 2. A discharge passage provided to branch from the main passage communicating the pressurization source and the wheel brake; a fixed valve seat provided in the discharge passage and having a liquid passage constituting the discharge passage; and this fixed valve. A movable valve body that can open and close this fluid passage by contacting and separating from a seat, an armature that can move the movable valve body by electromagnetic force, and an electromagnetic coil that is mounted on the exterior and has one end facing the armature. It has a stator that attracts the armature by electromagnetic force when power is supplied, and a spring that urges the armature in a direction away from the stator and that brings the movable valve body into contact with the fixed valve seat when not energized to close the liquid passage. a normally closed discharge valve that can be opened by electromagnetic force when supplied with electricity to communicate the discharge passage; an inlet provided at the branch point and communicating with the pressurizing source; a first outlet communicating with the wheel brake; a second valve communicating with the discharge valve;
a hollow cylindrical inner cylinder having three outlet ports; a spool that is slidably fitted into the inner cylinder and has a liquid passageway including an orifice, and the communication state of each port can be switched; It has a return spring that biases this spool in one direction, and when the antilock is not activated, the spool is in the inactive position and the inlet and the first outlet are connected through a large flow path, and when the antilock is depressurized, the discharge valve is opened. By activating the valve and discharging the hydraulic fluid from the second outlet to the discharge path, the spool moves against the biasing force of the return spring due to the biasing force due to the differential pressure generated at both ends of the spool, and the spool moves between the first outlet and the second outlet. When the outlet is connected to allow the wheel brake hydraulic fluid to be discharged to the discharge path, and the discharge valve is de-energized when the antilock is pressurized, the flow of the hydraulic fluid from the second outlet to the discharge valve is stopped, and the flow of the hydraulic fluid from the inlet to the discharge valve is stopped. When the liquid pressure is higher than the liquid pressure at the first outlet, it passes through the orifice from the inlet to the first outlet, forming a small flow path through which a small flow rate flows, and the difference in liquid pressure between the inlet and the first outlet is equal to this differential pressure. and a flow rate switching valve configured such that the spool returns to a non-operating position by the biasing force of a return spring and communicates with the large flow path when the discharge valve is 2 in series with the exit, and
The movable valve body and the armature are arranged so as to be present in the discharge passage on the opposite side of the side communicating with the second outlet with the fixed valve seat as a boundary, and the movable valve body and the fixed valve seat are sealed when the discharge valve is not energized. The structure is such that the biasing force of the spring in the discharge valve acts on the movable valve body against the force of hydraulic pressure at the second outlet acting on the effective diameter, and the return spring is connected between the second outlet and the discharge valve. An anti-lock device characterized in that the anti-lock device is disposed in a return spring chamber interposed between the two.