JPH11268630A - Brake hydraulic pressure control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent rusting of a piston due to a brake fluid not being discharged from a reservoir with a hydraulic pump by installing a cap so as to cover an opening which communicates with atmosphere in the air chamber of the reservoir and devising the shape of the opening communicating the air chamber with atmosphere. SOLUTION: Reservoirs 30A, 30B are built into a unit H which is a first main body in an anti-skid control device. Also, a passage for connecting each brake fluid storage chamber S with a wheel cylinder W/C side and a master cylinder M/C side is formed. Further, a control unit having a built-in controller for controlling solenoid valve device or the like, as a second main body, is integrally provided with the unit H. A first opening Ha which opens to an air chamber A is formed in such unit H. Further, a cap 95 is attached via a gasket 96 so as to cover an opening Hc of the reservoir formed in the unit H to seal against the atmosphere.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a brake fluid pressure control device.

[0002]

2. Description of the Related Art For example, according to an anti-skid control device described in Japanese Patent Application Laid-Open No. Hei 6-32223, in a master cylinder 1, a brake pedal 2 is connected to a cylinder body 4 via a booster 3 as shown in FIG. It is connected to a brake fluid storage reservoir 5. Two hydraulic pressure generating chambers are defined in the cylinder body 4, and when the brake pedal 2 is depressed, pressure is generated in the pipelines 6a and 6b, and the pipeline 6a is formed in the right front wheel 9a and the left front wheel 9b as described later. The other pipe line 6b is connected to the right rear wheel and the left rear wheel via a similar configuration.

[0003] A first two-port, two-position electromagnetic switching valve 7A is connected to the conduit 6a, and a wheel cylinder 10a of the right front wheel 9a is connected to this. The wheel cylinder 10a is connected to the reservoir 16 via a second two-port, two-position electromagnetic switching valve 8A.

[0004] As is known, the reservoir 16 is provided with the casing 1.
9 and a cylinder which divides the internal space into two, and a spring 18 which urges the cylinder upward in the figure, and defines a reservoir chamber above the piston 17.

[0005] Line 6a also includes a similar first two ports,
The wheel cylinder 1b is connected to the wheel cylinder 11b of the left front wheel 9b via a two-position electromagnetic switching valve 7B.
1b is also connected to the above-described reservoir 16 via a second two-port, two-position electromagnetic switching valve 8B.

Further, a check valve 1 is provided in parallel with the above-mentioned first and second two-port, two-position electromagnetic switching valves 7A, 7B, 8A, 8B.
4a, 14b and 15a, 15b are connected.
Further, the wheel speed sensor 11 is located close to the wheels 9a and 9b.
a and 11b are provided.

Although not shown, these sensors 11a, 11b
Is received by the controller, and it is determined whether the brake should be released or held, and the above-described electromagnetic switching valve 7A,
The solenoids 12a, 12b and 13a, 13b of 7B, 8A, 8B are energized or de-energized.

When the driver depresses the brake pedal, a hydraulic pressure is generated in the cylinder body 4, which passes through the first two-port, two-position solenoid-operated switching valves 7A, 7B and the left and right front wheels 9
A and 9B are supplied to the wheel cylinders 10a and 10b, and the wheels 9A and 9B are braked. When the controller (not shown) determines that the brake should be released now, the first two-port, two-position electromagnetic switching valve 7
A and 7B are energized, and the solenoids 13a and 13b of the second two-port two-position electromagnetic switching valves 8A and 8B are also energized. This makes the first
The two-port, two-position solenoid-operated switching valves 7A, 7B are shut off, and the second two-port, two-position solenoid-operated switching valve 8A,
8B becomes a communication state. As a result, the hydraulic fluid from the wheel cylinders 10a and 10b passes through the second two-port, two-position electromagnetic switching valves 8A and 8B, and discharges the brake fluid to the reservoir 16. This releases the brake.

When a controller (not shown) determines that the brake should be kept constant, the first two-port, two-position solenoid-operated directional control valves 7A and 7B are shut off, and the second two-port solenoid valves 7A and 7B are closed. The two-position electromagnetic switching valves 8A and 8B are also shut off. Therefore, the wheel cylinders 10a, 1
0b holds a constant brake fluid pressure. In the above-described anti-skid control device, conventionally, there is no hydraulic pump provided, and therefore, the amount of the brake fluid discharged to the reservoir 16 to reduce the brake fluid pressure is determined by the capacity of the reservoir 16, Therefore, the capacity of the reservoir 16 is determined in order to perform predetermined anti-skid control. However, the control method is different from the conventional method, and various parameters such as road surface conditions, wheel acceleration, and wheel speed are considered. Thus, the amount of brake fluid discharged to the reservoir 16 is made as small as possible.

When the driver releases the brake pedal 2 in order to release the brake, the brake fluid stored in the reservoir 16 flows through the pipeline 20, the check valves 15a, 1b, and 1b.
It is returned to the master cylinder 1 through 5b and 14a, 14b. As a result, the brake is released. Regardless of whether the anti-skid control is being performed or not, if the second two-port, two-position electromagnetic switching valves 8A, 8B are in the shut-off state, the wheel cylinder 10a As long as the fluid pressure of 10b is higher than the pressure of the brake fluid stored in the reservoir 16, it cannot be returned to the master cylinder side. Therefore, the brake fluid cannot be quickly discharged from the reservoir 16.

In view of the above-mentioned problems, the present applicant has eliminated the need for a hydraulic pump as in the above-described conventional example, and has made it possible to eliminate noise and pulse pressure vibration by this hydraulic pump in any case. As soon as the pedaling force on the brake pedal connected to the master cylinder is released, the brake fluid stored in the reservoir is returned to the master cylinder side,
The object is to provide an anti-skid control device that can immediately cope with the next anti-skid control.
A master cylinder and a wheel cylinder are connected via a first two-port two-position solenoid-operated switching valve, and the wheel cylinder and a reservoir are connected via a second two-port two-position solenoid-operated switching valve. When increasing the hydraulic pressure, the first two-port two-position solenoid-operated switching valve takes the communicating position, the second two-port two-position solenoid-operated switching valve takes the shut-off position, and the hydraulic pressure of the wheel cylinder decreases. When the first two-port two-position solenoid-operated directional control valve is in the shut-off position, the second two-port two-position solenoid-operated directional control valve is in the communication position, and the brake pressure fluid of the wheel cylinder is supplied to the reservoir. In the anti-skid control device configured to discharge, a pipe is provided that directly connects the reservoir and the master cylinder, and the pipe has a forward direction toward the master cylinder. A check valve is connected, and when the pedaling force on the brake pedal coupled to the master cylinder is released, the brake fluid in the reservoir is returned to the master cylinder via the check valve. An anti-skid control device has been disclosed.

Hereinafter, the detailed configuration and operation will be described with reference to the drawings.

FIG. 20 is a diagram showing a piping system of the anti-skid control device developed above. Parts corresponding to those of the prior art are denoted by the same reference numerals, and detailed description thereof will be omitted.

That is, according to this embodiment, the master cylinder 1
One of the systems is connected to the wheel cylinders of the right front wheel FR and the left rear wheel RL via a line 31a, and the other brake system is connected to the wheel cylinder of the left front wheel FL and the right rear wheel RR via a line 31b. Wheel cylinders are connected. That is, X piping is adopted. Also, the second
2 port, 2 position electromagnetic switching valve 8A, 8B, 8C, 8D
In the conventional example, a check valve is provided in parallel with the conventional example, but this is omitted. Further, in the conventional example, the reservoir is one for two wheels belonging to one system, but is an H-pipe system and belongs to one system according to the present invention. However, the right front wheel FR and the left rear wheel RL are provided.
For example, a reservoir 30A is provided for the reservoir 30A, the left front wheel FL, and the right rear wheel RR. These are directly connected to pipe lines 31a and 31b communicating with the first and second hydraulic pressure generation chambers of the master cylinder 1, and check valves 32a and 32b having a forward direction toward the master cylinder 1 side. 32b are provided. The first two-port, two-position solenoid-operated directional control valves 7A, 7B, 7C, 7D are provided in parallel with a check valve g having a forward direction toward the master cylinder 1.
Is provided.

That is, when increasing the pressure fluid in the wheel cylinder, the first two-port, two-position electromagnetic switching valve 7A,
7B, 7C and 7D are in the communicating position, through which the hydraulic fluid is supplied to the wheel cylinder and the brake is applied.

If the control unit (not shown) determines that the brake should be released (all wheels are assumed to change in the same skid state for the sake of simplicity of explanation), the second two-port, two-position system is used. The solenoids of the electromagnetic switching valves 8A to 8D are excited to be in a communication state, while the first two-port, two-position electromagnetic switching valves 7A to 7D are connected.
The solenoid of D is also excited to be in a cut-off state. As a result, the pressure fluid of the wheel cylinder is supplied to the second two ports,
The reservoir 30A passes through the two-position electromagnetic switching valves 8A to 8D,
It is discharged to 30B. As a result, the brake is released. According to the present embodiment, no hydraulic pump is provided similarly to the conventional example, so that the brake fluid discharged to the reservoirs 30A and 30B remains stored. That is,
The amount of release of the brake is determined by the capacity of these reservoirs 30A and 30B.

When the control unit (not shown) first determines that the brake should be held, it excites the solenoids of the first two-port, two-position solenoid-operated switching valves 7A to 7D to produce the second two-port, two-position solenoid. The hydraulic fluid in the wheel cylinders is maintained at a constant hydraulic pressure while the solenoids of the electromagnetic switching valves 8A to 8D remain de-energized. Therefore, the brake pressure of the wheel is kept constant.

When increasing the braking force, the solenoids of the first two-port, two-position solenoid-operated switching valves 7A to 7D are intermittently excited to thereby increase the hydraulic pressure of the wheel cylinder stepwise. To increase the braking force, and when the control unit determines that the brake should be released again, the first 2
The ports and the two-position electromagnetic switching valves 7A to 7D are shut off, and the solenoids of the second two-port and two-position electromagnetic switching valves 8A to 8D are excited to be in a communicating state, and
The brakes on the wheels are released by discharging the brake fluid to A and 30B. Holding such braking force,
The loosening and the ascending of the stairs are set so as to be performed for a predetermined time by the control unit.
It is controlled according to the capacity of 0B. When the driver releases the depressing force on the brake pedal, the brake fluid stored in the reservoirs 30A and 30B now has a check valve due to the spring force of the built-in spring, regardless of the fluid pressure of the wheel cylinder. The valves 32a and 32b are opened and returned to the master cylinder 1 side. Therefore, the reservoirs 30A and 30B can be made almost empty to reduce the hydraulic pressure of the wheel cylinders of the wheels to zero. Further, according to the present embodiment, the second 2
Although the check valves are not provided in the ports and the two-position solenoid-operated switching valves 8A to 8D, even if the solenoids are in the non-excited state and in the shut-off state, the reservoirs 30A, 30A are surely immediately.
The brake fluid can be returned from B to the master cylinder, and the next anti-skid control can be dealt with.

According to this embodiment, the pipe lines 31a and 31b directly connect the master cylinder 4 and the reservoirs 30A and 30B as described above. , 32b are provided only, so that all the brake fluid stored in the reservoirs 30A, 30B can be returned to the master cylinder 4 reliably by the spring force of the built-in springs of the reservoirs 30A, 30B. The pressure loss is only the spring force of one check valve 32a, 32b.

In the conventional example shown in FIG. 19, the reservoir 16 is connected to the master cylinder 1 via the pipe 20, the check valve 15a, the pipe connecting the electromagnetic switching valves 12a and 13a, the check valve 14a, and the pipe 6a. It is connected. That is, the reservoir 16 is connected to the line 20, which is connected in parallel with the electromagnetic switching valve 13a, the line connecting the check valve 15a and the line connecting the electromagnetic switching valves 7a, 8a, Further, it is connected to the master cylinder 1 via a pipeline connected in parallel with the electromagnetic switching valve 7a and further via a pipeline 6a. That is,
The pipe is connected to the master cylinder 1 through two separate sections. Since the check valves 14a and 15a must be opened to allow the brake fluid to flow back to the master cylinder 1, the check valves 14a and 15a have two spring losses. When the brake pedal is released during the anti-skid control as described above, the pressure fluid from the wheel cylinder 10a of the wheel 9a is released from the master cylinder 1.
At this time, if the hydraulic pressure of the brake fluid stored in the reservoir 16 is higher than that of the reservoir 1,
6 cannot return the brake fluid to the master cylinder 1. However, in the configuration disclosed by the applicant earlier, only the check valves 32a and 32b are provided, so that the brake fluid is almost completely returned to the master cylinder 1.

The reservoirs 30A and 30B each have a piston whose outer periphery is sealed inside the main body and slidably fitted therein,
A brake fluid storage chamber defined on both sides of the piston, an air chamber, and a spring for urging the piston toward the brake fluid storage chamber; the spring force of the spring acting on the brake fluid storage chamber; The brake fluid is stored from the outside against the pressure, and the piston is moved backward by the spring force to discharge the brake fluid to the outside. The control device does not operate the hydraulic pump during the anti-skid control to forcibly recirculate the brake fluid from the brake fluid storage chamber to the master cylinder side, so there is almost no vertical movement of the piston, Accordingly, the opening of the air chamber is covered with a rubber cap with a slit (not shown), and air is allowed to enter and exit from the opening to smooth the movement of the piston. That is, sucks external dirt and moisture from the air hole, or rust out the outer periphery of the piston Hittsui around the piston, there is a case of difficult to perform a movement by dust. In this case, even if the brake fluid is discharged from the wheel cylinder to the brake fluid storage chamber, in extreme cases, without moving the piston,
In some cases, the brake fluid cannot be discharged from the wheel cylinder. With this, the original anti-skid control cannot be performed.

In the waterproof structure of the hydraulic control device disclosed in Japanese Patent Application Laid-Open No. Hei 8-261202, a construction is shown in which the anti-skid control device does not draw water into the air chamber of the reservoir as shown in FIG. I have. That is, as shown in FIG. 21, the reservoir 19 'provided in the housing 31' of the hydraulic control device includes an atmosphere communication chamber 48 'closed by the plug member 46 and the seal member 50'. Cover 3 coupled to the side of housing 31 '
2 housing the outer peripheral portion 50 ₁ of the sealing member 50 '3
An annular projection 32 pressed against and fixed to the plug member 1 'and the plug member 46'
Provided with a _11, a recess 32 ₉ the tip of the vent pipe 50 _{and second} sealing member 50 'faces. Housing 31 '
Drainage 64 formed between the lower cover 32 'flanges 32 ₈ and the housing 31 formed by bending the lower edge of the horizontal direction' space 61 leading to the 'air communicating chamber 48 is formed between' the cover 32 and Discloses a configuration that communicates with the atmosphere via a.

Even with such a configuration, it is possible to prevent the air chamber 48 'from becoming negative pressure due to the reciprocating motion of the piston of the reservoir and inhaling moisture from the outside to some extent. Since there is no intervening seal member between them, there is a sufficient risk that moisture or small foreign matter will be sucked in even during normal non-operation. Further, when the piston is reciprocated, the pressure in the air chamber 48 becomes negative, so that it is considered that there is a great possibility that foreign matter is easily sucked from the outside and adhered to the piston.

[0024]

SUMMARY OF THE INVENTION The present invention has been made in consideration of the above-described problems, and has as its object to provide a brake fluid pressure control device capable of preventing a piston from rusting or being unable to move due to foreign matter. Make it an issue.

[0025]

The object of the present invention is to provide a first body having a built-in reservoir and a solenoid valve device and having a passage for communicating a brake fluid storage chamber of the reservoir with the outside.
And a second body incorporating at least a controller for controlling the solenoid valve device, wherein the first and second bodies are integrated into a brake fluid pressure control device,
A piston fitted with a seal ring in a cylinder hole formed in the first main body and slidably fitted thereto; a brake fluid storage chamber defined in the cylinder hole by the piston; A brake fluid pressure control device comprising a chamber and a spring for urging the piston toward the brake fluid storage chamber, wherein the first body has a first opening opening to the air chamber; And a second opening formed in a gap formed in communication with the atmosphere between the second main body and the second main body. The second opening is formed below the first opening. A cap is attached to an opening formed in an end wall of the first main body through a seal member between the first main body and the first main body, and the first opening is located inside the air chamber from the seal member. Brake located on the side It is solved by the pressure control device.

[0026]

Embodiments of the present invention will be described below with reference to the drawings. The same reference numerals are given to portions corresponding to the anti-skid control device shown in FIG. 20 developed earlier by the present applicant, and detailed description thereof will be omitted.

That is, according to the embodiment of the present invention,
In FIG. 1, a filter f is connected to the input port side and / or the output port side of each of the electromagnetic switching valves 7A to 7D and 8A to 8D. Further, two ports are formed in each of the reservoirs 30A and 30B, and a filter f is connected to one end of the discharge pipe R at the end. Pipe lines 31a'a and 31b'a are connected to the other port,
In the same manner as the previously developed device, the check valves 32a 'and 3
2b 'is connected with the direction toward the master cylinder 4 being the forward direction.

FIGS. 2 to 5 show the HU units H and E described above.
The U unit E is shown in its entirety. In the figure, a unit H as a first main body is provided inside a main body and a reservoir 3 described later in detail.
0A and 30B are built in, and a passage for connecting the brake fluid storage chamber to the wheel cylinder side and the master cylinder side is formed. Also, the unit E is an anti-skid control circuit incorporates a controller ECU for mainly, the wheel speed sensors w ₁ to w aforementioned solenoid valve in response to an output of ₄ 7A-7D, the solenoid portion s of 8A~8D Control. Also, the electromagnetic switching valves 7A to 7C receiving the control signal
7D and 8A to 8D are built in the unit H.
2 to 5, the unit H and the unit E are integrated by a bolt B, and the whole is fixed to the vehicle body by a bolt L.

The connection ports RLA and RRA are connected to the wheels RL.
And RR are connection ports for connecting pipes to wheel cylinders, and FRA and FLA are connection ports for connecting pipes connected to wheel cylinders of wheels FR and FL. As shown in FIG. 1, MC1 and MC2 are connection ports for connecting pipelines 31a 'and 31b' to the master cylinder. According to the invention, it extends horizontally between the unit bodies H and E, ie in FIG.
A gap G extending from the other side of the drawing to the front is formed. This communicates with a passage Y communicating with the air chambers of the reservoirs 30A and 30B, as described later.

In FIG. 11, a portion H surrounded by a two-dot chain line is a so-called hydraulic unit (Hydra).
ulic unit) and indicates a hydraulic control unit. As will be described later, it is integrally built in the first main body H.
Also, as will be described later, an ECU is provided in the second main body E.
(Electric Control Unit) controller. It no 7D and 8A to no solenoid valves 7A the solenoid portion s of 8D are supplied to the control signal s ₁ and s ₂ from the controller ECU, by performing a known anti-skid control. Further, wheel speed sensors w ₁ , w ₂ , w ₃ and w ₄ are provided close to the wheels FR, RL, RR and FL, and the wheel speed signals are supplied. It is determined by a known logic whether the brake should be released, held or increased, and based on this determination, the solenoid s of each of the solenoid valves 7A to 7D and 8A to 8D is controlled.

Next, the details of the reservoir 30A according to the present invention will be described with reference to FIG. Since the other 30B has the same configuration, only one of them will be described.

This corresponds to each of the electromagnetic switching valves 7A to 7D shown in FIG.
And 8A to 8D. The piston 90 of the reservoir 30A has a U-shaped cross section, is fitted with a seal ring g and is slidably fitted in a cylinder hole 91, and has a brake fluid storage chamber S and an air chamber A on both sides thereof. Has formed. The Note sealing ring g is the stopper S, are held to the position shown, the air chamber A ₁ and spring 93 is arranged, by which one end is spring receiving 94, has been received, this is The stop ring 92 allows the cylinder hole 9
The position shown in FIG. This central portion has a communication hole 94a, and a cap 95 made of aluminum is formed of a liquid gasket (silicon oil) so as to be aligned with the communication hole 94a so as to cover an opening Hc for a reservoir formed in the main body H.
96 is applied and press-fitted and sealed and fixed to the atmosphere. As shown in FIG. 1, the brake fluid storage chamber S is provided in a pipe R that can communicate with the wheel cylinder via a filter f, and the other port has a direction toward the master cylinder. Check valve 3 for forward direction
2a 'is provided. Further according to the invention, the body H
And a first opening Ha is formed in the cylinder hole 91,
Further, openings Hb are formed toward the atmosphere.
a and Hb are connected by a passage Y extending obliquely with respect to the moving direction of the piston 90. The piston 90 is in the case of discharging the brake fluid to the reservoir chamber S against the spring force of the spring 93 is to move to the right in FIG., Path Y is in the reservoir chamber S when this full stroke It has a capacity sufficiently larger than the capacity, and communicates with a gap G formed between the main bodies H and E as shown in FIG.

Next, referring to FIG. 7, the above-described check valve 32a 'will be described.
Will be described. The valve seat forming member 99 has a passage 99a formed between the conduit 31a'a and the reservoir chamber S. The upper end of the passage 99a is tapered as a valve seat of the valve ball 98. I have. A spring retainer 102 is fixed to the valve seat forming member 99, and a retainer 101 is in contact with the valve ball 98 so that the valve ball 98 operates stably. A valve spring 100 is stretched between the valve retainer 101 and the spring retainer 102. Have been.

Next, FIGS. 8 to 10 show a filter f provided in a pipe connected to another port of the reservoir.
This will be described with reference to FIG. That is, both ends of the cylindrical filter net N as a mesh are attached at both ends of the mounting casing 110 as shown in FIG. 5, and as is apparent from FIG. At the reservoir side and the pipeline R side via a mesh surface N. The reservoir 30A according to the embodiment of the present invention is configured as described above. Next, its operation will be described.

When the anti-skid control is performed as is well known, brake fluid is discharged from the wheel cylinder to the reservoir chamber S via the pipe line R, but the brake fluid pressure opposes the spring force of the spring 93. To move the piston 90 to the right. At this time, the pressure in the air chamber A is not increased, but moves to the right smoothly with almost no air resistance through the passage Y, and the brake fluid is stored in the reservoir chamber S. Note that the increase in the capacity of the reservoir chamber S due to the rightward movement of the piston 90 is much smaller than the capacity of the passage Y (the capacity of the gap G is also added thereto), so that the movement of the piston 90 is very smooth. .

According to the present embodiment, the anti-skid control device does not use a hydraulic pump. The anti-skid control operation is performed extremely quietly. However, when the driver depresses the brake pedal, the spring is released. Due to the spring force of 93, the piston 90 moves to the left in the figure. At this time, the pressure in the air chamber A is reduced to a negative pressure.
Even if 0 is a full stroke, since the capacity of the passage Y is formed much larger than the capacity increase of the reservoir chamber S , almost no negative pressure is generated, so that fine water droplets and dust can be sucked from the atmosphere. Absent. The brake fluid returns to the master cylinder by opening the check valve 32a '. When the brake fluid is discharged from the wheel cylinder into the reservoir chamber S , fine dust is removed from the filter f, and proper anti-skid control can always be performed with normal brake fluid.

The anti-skid control operation is performed as described above. However, according to the present invention, since the passage Y is formed, fine dust and water droplets do not adhere to the outer peripheral portion of the piston 90. It is not rusted or moved by dust, and the original anti-skid effect is not lost. Further, a cap 95 made of aluminum covers an opening of the main body H forming the atmosphere chamber A , and is sealed with a liquid gasket 96 from the atmosphere. Since it is formed inward of the air chamber A , it is possible to effectively prevent the above-mentioned suction of moisture and dust. The cap member 95 is provided with an opening communicating with the atmosphere as in the related art, for example, a slit is formed in a rubber plate so that when a negative pressure or a high pressure is applied, the opening is opened so that air can be sucked in from the atmosphere or air can be introduced into the atmosphere. Is not discharged, so that the above-described actions and effects without water entering can be reliably obtained. That is,
Since a conventional rubber cap with a slit is provided so as to face the movement direction of the piston 90, the rubber easily bends to introduce or take out air. However, since the passage Y is formed obliquely downward with respect to the moving direction of the piston 90, it is difficult to suck dust and moisture. In addition, the large capacity facilitates the movement of the piston 90.

FIG. 11 shows a piping system of an anti-skid control device according to a second embodiment of the present invention. Components corresponding to those of the above-described embodiment are denoted by the same reference numerals, and will be described in detail. Is omitted. That is, according to the present embodiment, instead of using two 2-port 2-position electromagnetic switching valves, one 3-port 3-position electromagnetic switching valve is used, and
A, 40B, 40C, 40D are connected to the wheel cylinders and reservoirs 30A, 30B, respectively. The configuration and operation of the reservoirs 30A and 30B are the same as in the first embodiment. Incidentally, the wheel speed sensors w ₁ to w ₄ and controller EC
U is not shown.

Next, the third embodiment of the present invention will be described with reference to FIG.
An embodiment will be described. This embodiment is different from the illustrated first embodiment in the configuration of a first two-port, two-position electromagnetic switching valve. That is, the first two-port, two-position electromagnetic switching valve 40 according to the embodiment of the present invention functions according to the operation and principle as shown in FIGS. That is, as shown in FIG. 12A, a valve ball 44 is disposed in the main body 41, and the valve ball 44 is formed in the main body 41.
1a is provided so as to be able to be put on and taken off. A current having a magnitude indicated by an arrow A is supplied to a solenoid (not shown) to urge the valve ball 44 downward. As a result, an opening 43 communicating with the master cylinder 1 and openings 42a and 42b communicating with the wheel cylinder are formed in the main body 41.
a, and the master cylinder side and the wheel cylinder side are shut off. That is, it is in the cutoff state. This is because even if the pressure difference ΔP between the hydraulic pressures on the master cylinder side and the wheel cylinder side is large (FIG. 12B) or small (FIG. 12A), the current A is maintained so as to maintain this interrupted state. The size is determined.

Next, as shown in FIGS. 13A and 13B, when it is desired to open the valve ball 44, the magnitude of the current A is changed according to the differential pressure ΔP for the same opening degree. That is, as shown by A in FIG. 12, when the differential pressure ΔP is small, the current value A ′ is small to form a constant opening Q. Also,
When the pressure difference ΔP between the hydraulic pressures on the master cylinder side and the wheel cylinder side is large, the current A ″
Is large.

Next, a computer program in a control unit (not shown) provided in the anti-skid control device according to the third embodiment of the present invention will be described. As shown in FIG. 14, the process starts at step 51, and at step 52, each circuit of the computer is initialized. Next, in step 53, the output of the wheel speed sensor is received, and each wheel speed is calculated. Next, the wheel acceleration is calculated in step 54 by differentiating the wheel speed,
Based on this output, braking control of each wheel is performed in step 55.

Next, braking control for each wheel will be described with reference to FIG. In step 61, the braking control for one wheel is started, and the wheel speed is calculated in step 53 as shown in FIG.
If the maximum speed from the two wheels is the vehicle speed, and if the wheel to be controlled is the right front wheel, the wheel speed of this front wheel,
A slip ratio λ is calculated in step 62 based on the vehicle speed. Next, in step 63, the slip ratio λ and step 5 in the flowchart shown in FIG.
The instability of the wheel is calculated from the wheel acceleration α of No. 4.

According to the present embodiment, the degree of instability determines whether the wheels are in a locked state or in a stable state. Then, in decision step 64, this A
It is determined whether or not the BS has been started, and if NO, it is determined in step 64a whether or not the wheels are unstable.
If no, the process returns to step 61 again, and the processes of steps 62, 63, and 64 are repeated. If yes, the slip ratio λ has been calculated from the wheel speed and the vehicle speed described above, and the friction coefficient μ of the road surface is determined from this. According to the present embodiment, three types of μ of high, middle, and low are determined. Next, a difference ΔP between the hydraulic pressure on the master cylinder side and the hydraulic pressure on the wheel cylinder side is calculated. In the present embodiment, the calculation is performed based on how the wheel speed changes after the brake pedal is depressed. Instead, the hydraulic pressure on the master cylinder side and the hydraulic pressure on the wheel cylinder side are calculated. Detection may be performed by some method, and the differential pressure ΔP may be obtained from the difference between the detection outputs.

Next, at step 67, the slip ratio λ, the friction coefficient μ of the road surface is determined to be high, medium or low, and the magnitude of the hydraulic pressure difference ΔP between the master cylinder and the wheel cylinder. The first two-port, two-position solenoid-operated switching valve (in the flowchart, the pressure-intensifying valve) 40 is opened and closed, and if it is open, how to set its opening degree Q. It is determined whether the time is to be maintained (this is ΔT). Then, after that, the hydraulic pressure of the wheel cylinder is increased, maintained, or reduced. Before starting the operation, the instant of the clock time is set to T _0.
Thereafter, in steps 70, 71 and 72, the pressure is increased, held or reduced.

First, when increasing the pressure, in FIG.
From step 70 to the next step 81, the value of the current flowing through the solenoid of the first two-port two-position solenoid switching valve 40 is set by the control unit, or the second two-port two-position solenoid switching valve 8A is set. The ~ 8D solenoids are not energized. Each of the factors is calculated in step 67 in FIG. 15, whereby a current value I (Q) for obtaining a constant opening Q is caused to flow through the solenoid portion, thereby indicating by A or B in FIG. 3. As described above, the opening degree Q between the valve ball 44 and the valve seat 41a is obtained, but in response to this, the brake fluid is supplied from the master cylinder side to the wheel cylinder side to increase the hydraulic pressure of the wheel cylinder. . This time T is counted in step 82, and it is determined whether it is greater or equal from the sum of the above-described clock start time T ₀ and the duration ΔT. If the result is NO, the same operation is performed through step 81 in the pressure increasing mode, and T
_{If the} time is greater than ₀ + ΔT, the result is yes, and the process returns to the return 83. That is, the solenoids of the magnetic switching valves 8A to 8D for these wheels, that is, the right front wheels, are not excited. Each of the factors is calculated in step 67 in FIG. 15, whereby a current value I (Q) for obtaining a constant opening Q is caused to flow through the solenoid portion, thereby indicating by A or B in FIG. 3. As described above, the opening degree Q between the valve ball 44 and the valve seat 41a is obtained. In accordance with this, the brake fluid is supplied from the master cylinder side to the wheel cylinder side to increase the hydraulic pressure of the wheel cylinder. . This time T is counted in step 82,
From the sum of the above clock start time T ₀ and the duration ΔT,
Determine if it is large or equal. If a result is NO, further was treated in the same manner through the steps 81 in the pressure increase mode, the time from T ₀ + [Delta] T is large, it is yes, the flow returns to the return 83. That is, the control cycle for this wheel, that is, the right front wheel is completed, and then the same flowchart shown in FIG. 15 is executed for the left front wheel.

Next, the holding mode 71 will be described.
As shown in FIG. 17, the holding mode starts at step 71, and at step 84, the value of the current flowing through the solenoid of the first two-port, two-position electromagnetic switching valve 40 is set to a value corresponding to the opening degree 0. . As a result, the first two-port, two-position electromagnetic switching valve 40 is turned off. On the other hand,
The second 2-port, 2-position electromagnetic switching valves (referred to as pressure reducing valves in the flowchart) 8A to 8D remain off. Therefore, the hydraulic pressure of the wheel cylinder is maintained. It is determined whether the current time is large or small based on a value obtained by adding a predetermined duration ΔT set from the time T ₀ when the holding mode starts, and if the current time is small, steps 71 and 84 are similarly performed. repeat. If yes, the control for the next wheel is performed.

Next, the decompression mode 72 will be described.
As shown in FIG. 18, in step 85, the current flowing through the solenoid of the first two-port, two-position electromagnetic switching valve 40 is set to the same value as in the holding mode. Thereby, the first
The two-port, two-position electromagnetic switching valve 40 is shut off,
On the other hand, a predetermined current flows through the solenoids of the second two-port, two-position electromagnetic switching valves 8A to 8D. This allows
The brake fluid of the wheel cylinder is supplied to the reservoirs 30A and 30A.
B is discharged to B, and the braking force of the wheel is reduced. The start time of this decompression mode is T _0, and the duration is Δ
If T, whether the sum is smaller or larger than the current time, that is, whether the sum is no or yes, repeat this decompression mode if no, and if yes, other Move on to the braking operation of the wheel. As described above,
In the second embodiment as well, proper anti-skid control is performed. However, when the driver releases the pedaling force on the brake pedal, the brake fluid pressure stored in the reservoirs 30A and 30B is reduced by the check valve 32a. , 32b, and immediately return to the master cylinder 1 side to prepare for the next anti-skid control. Since no hydraulic pump is used, it is of course quieter than the conventional anti-skid control device in which it is used, and, of course, there is no kick pedal phenomenon toward the master cylinder.

Further, according to the present embodiment, the opening degree Q in the communication state of the first two-port two-position electromagnetic switching valve 40 is set.
Can be changed according to the magnitude of the current flowing through the solenoid portion, and this can be changed according to the pressure difference ΔP between the hydraulic pressure on the master cylinder side and the hydraulic pressure on the wheel cylinder side. When the driver depresses the brake pedal with a high pedaling force on the road surface, the opening degree Q of the first two-port, two-position electromagnetic switching valve 40 is changed in order to quickly apply a braking force corresponding to the pedaling force to the wheels. In order to increase the current, the current flowing through the solenoid is made relatively small. Therefore, even when a high pedaling force, that is, a panic brake is applied on a high μ road surface, it is possible to apply a sudden brake corresponding to this.

Next, when a brake is applied on a low μ road surface, the wheels tend to lock rapidly even with a small braking force, and in this case, the first two-port, two-position electromagnetic switching valve 40 The opening Q is made small, and the amount of liquid flowing from the master cylinder side to the wheel cylinder side is made small. This can prevent the lock from proceeding. That is, frequent anti-skid control is prevented and the reservoir 3
The amount of the brake fluid discharged to 0A and 30B can be made small, and the capacity of the reservoir can respond to complete anti-skid control of one cycle.

According to the present embodiment, the reservoir 30
Since the piston 90 of A and 30B always operates smoothly,
The above control can be reliably performed.

Although the embodiments of the present invention have been described above, the present invention is, of course, not limited to these, and various modifications can be made based on the technical concept of the present invention.

For example, in the above embodiment, the reservoir 30
A and 30B are respectively formed with two ports, one of which is connected to a filter f, and the other of which is a check valve 32a ', 32B.
b 'was connected. Alternatively, the present invention is applicable to a reservoir having one port. Even in this case, the filter f
It is possible to perform appropriate anti-skid control even though the check valve is connected without using the hydraulic pump without using the pump, but the pressure fluid from the wheel cylinder is discharged to one port, and From this port, check valve 32a ',
Return to the master cylinder 4 through 32b '.
Of course, one port may be provided with the check valves 32a 'and 32b' and the filter f.

In the above-described embodiment, the anti-skid control is performed without using the hydraulic pump. However, when the brake is released by using the hydraulic pump as in the related art, the brake is stored in the brake fluid storage chamber of the reservoir. The present invention is also applicable to an anti-skid control device in which the liquid is discharged and immediately pumped up by a hydraulic pump and returned to the master cylinder side or the supply valve side.

In the above-described embodiment, the opening of the air chamber of the reservoir formed in the main body H is fixed by the aluminum cap 95 with the sealing member 96 interposed therebetween, and the air chamber 95 a is formed in the cap 95. Although a convex shape is used for forming, a cap made of a flat aluminum plate or another metal or a rigid flat rubber may be used without being limited to such a shape. . Incidentally, as shown in FIG. 2, when the cap 95 having a convex portion, since only this volume of air chamber 95a that is formed by increasing the volume of the air chamber A, the capacity of the oblique passage Y of the present invention In conjunction with this, the movement of the piston 90 is made smoother.

In the above embodiment, only one diagonal passage Y extending from the top to the bottom is formed. However, a plurality of two or three passages Y may be formed.

In the above embodiment, the reservoir used for the anti-skid control device has been described. However, the brake fluid pressure control device is not limited to this, and other brake fluid pressure devices such as a drive slip control device and a VDC (V
Also, the present invention can be applied to an electronic dynamic control device.

In the above embodiment, a gap G is formed between the hydraulic unit main body H and the electronic unit main body E as the first main body as shown in FIG. Of course, without being limited to this position, it may be formed at another position depending on the shape of the main body H and the main body E. The gap G extends in the horizontal direction, but the main body H extends in the vertical direction.
The body E and the body E may be fixed by bolts B. In this case, drainage is facilitated.

[0058]

As described above, according to the brake fluid pressure control device of the present invention, even when the brake fluid in the brake fluid storage chamber is not forcibly discharged to the outside, it is possible to prevent the piston from rusting. It can be prevented that the movement becomes difficult due to the adhesion of dust or the like. Therefore, the original brake hydraulic pressure control can be reliably performed.

[Brief description of the drawings]

FIG. 1 is a piping diagram of an anti-skid control device including a reservoir according to a first embodiment of the present invention.

FIG. 2 is a plan view showing integration of a unit H and a unit E according to the embodiment of the present invention.

FIG. 3 is a partially cutaway view of the side view.

FIG. 4 is a front view of the same.

FIG. 5 is a rear view of the same.

FIG. 6 is a partially enlarged sectional view showing details of a reservoir in FIG. 1;

FIG. 7 is an enlarged sectional view of a check valve connected to a port of the reservoir.

FIG. 8 is a front view of a filter connected to the other port of the reservoir.

9 is a sectional view taken along the line [9]-[9] in FIG.

FIG. 10 is a sectional view taken along the line [10]-[10] in FIG.

FIG. 11 is a piping diagram of an anti-skid control device according to a second embodiment of the present invention.

FIG. 12 shows a principle diagram of a first two-port, two-position solenoid-operated switching valve according to a third embodiment of the present invention, where A is a pressure difference ΔP of hydraulic pressure between the master cylinder side and the wheel cylinder side. And B shows the magnitude relationship of the current flowing through the solenoid when the pressure difference ΔP of the hydraulic pressure between the master cylinder and the wheel cylinder is large. It is.

FIG. 13 also shows a first embodiment according to the third embodiment of the present invention.
The relationship between the magnitude of the current flowing through the solenoid for obtaining a constant opening degree of the two-port, two-position solenoid-operated directional control valve is shown in FIG.
FIG. 7B is a diagram showing a case where P is small and B is a case where ΔP is large.

FIG. 14 is a program chart set in a computer in a control unit according to the third embodiment of the present invention.

FIG. 15 is a program chart of braking control of one wheel in the same program chart.

FIG. 16 is a flowchart in a pressure increasing mode.

FIG. 17 is a flowchart in a holding mode.

FIG. 18 is a flowchart in a pressure reduction mode.

FIG. 19 is a piping diagram of a conventional anti-skid control device.

FIG. 20 is a piping diagram of an anti-skid control device developed earlier by the present applicant.

FIG. 21 is a partially enlarged cross-sectional view showing a main part of a conventional reservoir.

[Explanation of symbols]

30A Reservoir 30B Reservoir 90 Piston 93 Spring 95 Cap A Air Chamber S Brake Fluid Storage Chamber Y Passage

Claims (10)

[Claims] 1. A first body having a reservoir and an electromagnetic valve device built therein and forming a passage for externally communicating a brake fluid storage chamber of the reservoir, and a controller for controlling at least the electromagnetic valve device. A brake fluid pressure control device comprising the first and second bodies integrated with each other, wherein the reservoir is provided with a seal ring in a cylinder hole formed in the first body. A piston fitted and slidably fitted, a brake fluid storage chamber defined in the cylinder hole by the piston, an air chamber, and a spring for urging the piston toward the brake fluid storage chamber. In the brake fluid pressure control device, the first body has a first opening that opens into the air chamber, and a gap formed between the first body and the second body in communication with the atmosphere. Open to the said The second position is located below the first opening.
Forming an opening, connecting the first opening and the second opening,
A cap is attached to an opening formed in the end wall of the first main body via a seal member between the first main body and the first main body, and the first opening is located on the inner side of the air chamber from the seal member. A brake fluid pressure control device characterized by being located. 2. The brake fluid pressure control device according to claim 1, wherein the passage extends obliquely with respect to a moving direction of the piston. 3. The apparatus of claim 1, wherein the second opening is downward.
Or the brake fluid pressure control device according to 2. 4. The electromagnetic valve device includes first and second two-port two-position solenoid-operated switching valves, and connects a master cylinder and a wheel cylinder via the first two-port two-position solenoid-operated switching valve. When the wheel cylinder and the brake fluid storage chamber are connected via the second two-port two-position electromagnetic switching valve and the hydraulic pressure of the wheel cylinder is increased, the first two-port two-position electromagnetic switching valve is In the communication position, the second 2-port 2-position electromagnetic switching valve is set to the shut-off position, and when decreasing the hydraulic pressure of the wheel cylinder, the first 2-port 2-position electromagnetic switching valve is set in the shut-off position. The second two-port two-position solenoid-operated directional control valve is for an anti-skid control device in which a communication position is set to discharge brake pressure fluid of the wheel cylinder to the brake fluid storage chamber. The brake fluid pressure control device according to any one of claims 1 to 3, wherein: 5. The electromagnetic valve device comprises a 3-port 3-position electromagnetic switching valve, wherein the 3-port 3-position electromagnetic switching valve is connected between a master cylinder and a wheel cylinder to increase the hydraulic pressure of the wheel cylinder. The three-port three-position electromagnetic switching valve takes a first position for communicating the master cylinder with the wheel cylinder, and takes a second position that is a shut-off position when the wheel cylinder holds a hydraulic pressure; When lowering the hydraulic pressure of the wheel cylinder, a third position is provided for allowing the wheel cylinder to communicate with the brake fluid storage chamber, and the brake pressure fluid of the wheel cylinder is discharged to the brake fluid storage chamber. The brake fluid pressure control device according to any one of claims 1 to 3, which is used for an anti-skid control device. 6. A pipe line directly connecting the brake fluid storage chamber and the master cylinder, and a check valve having a forward direction to the master cylinder is connected to the pipe line, and the master cylinder is connected to the master cylinder. The brake fluid in the brake fluid storage chamber is returned to the master cylinder via the check valve when the pedaling force applied to the brake pedal to be coupled is released. Brake fluid pressure control device. 7. The solenoid valve according to claim 4, wherein the first two-port two-position solenoid-operated directional control valve is capable of adjusting a communication opening degree in the communication position by controlling a current to the solenoid portion. Brake fluid pressure control device. 8. The current control for the solenoid portion is performed in accordance with a pressure difference ΔP between the master cylinder side hydraulic pressure and the wheel cylinder side hydraulic pressure for a constant communication opening degree. Item 8. The brake fluid pressure control device according to Item 7. 9. The method according to claim 9, wherein the time ΔT for maintaining the constant communication opening degree is adjusted in accordance with at least one of the differential pressure ΔP, a wheel slip condition, and a road surface friction coefficient μ. The brake fluid pressure control device according to claim 8. 10. A filter is provided in a port for introducing the brake fluid discharged from the wheel cylinder into the brake fluid storage chamber, and the check valve is provided in a port for returning the brake fluid to the master cylinder side. The brake fluid pressure control device according to any one of claims 6 to 9, wherein: