JPH034411B2 - - Google Patents

Description

[Detailed Description of the Invention] A. Object of the Invention (1) Industrial Application Field The present invention relates to a brake hydraulic control device for a vehicle, particularly an input hydraulic chamber communicating with an output port of a master cylinder, and an input hydraulic chamber communicating with a wheel brake. It has an output hydraulic pressure chamber that generates braking hydraulic pressure according to the hydraulic pressure in the hydraulic chamber,
The present invention relates to a brake hydraulic control device for a vehicle configured to increase the volume of an output hydraulic chamber in response to supply of control hydraulic pressure from an anti-lock control means to a control chamber when a wheel is about to enter a lock state.

(2) Conventional technology Conventionally, such a brake hydraulic control device for a vehicle operates a piston according to the oil chamber of the input hydraulic chamber to reduce the volume of the output hydraulic chamber, thereby adjusting the braking hydraulic pressure corresponding to the input hydraulic chamber. is generated from the output hydraulic chamber, and during anti-lock control, the piston is actuated in the opposite direction to the aforementioned direction by the control hydraulic pressure supplied to the control chamber to increase the volume of the output hydraulic chamber.

(3) Problems to be solved by the invention In the above conventional vehicle brake hydraulic control device,
The brake hydraulic system is separated into two parts: from the master cylinder to the input hydraulic chamber, and from the output hydraulic chamber to the wheel brakes. Therefore, when filling the brake hydraulic system with hydraulic oil, it is necessary to fill both of them. It was necessary to do it. Therefore, in order to unify the braking hydraulic system from the master cylinder to the wheel brakes and to facilitate the filling of hydraulic oil, a valve mechanism that closes during anti-lock control is installed between the input hydraulic chamber and the output hydraulic chamber. is possible.

In addition, in conventional vehicle brake hydraulic control devices, the braking force applied to wheels with a large supported load, such as the front wheels, is lower than the braking force applied to wheels with a smaller supported load, such as the rear wheels, in accordance with the distribution of the supported load. A proportional pressure reducing valve is generally provided to proportionally reduce the hydraulic pressure and apply it to the wheel brakes.

Therefore, as mentioned above, a valve mechanism that closes during antilock control is interposed between the input hydraulic chamber and the output hydraulic chamber to unify the braking hydraulic system, and the valve mechanism is also equipped with a proportional pressure reducing valve. If this function could be added, filling the hydraulic oil would be easier, and it would be possible to simplify the structure, reduce weight, and improve reliability.

The present invention has been made in view of the above circumstances, and provides a vehicle brake hydraulic system that facilitates the filling of hydraulic fluid into a brake hydraulic system, and that also has a simplified structure, reduced weight, and improved reliability. The purpose is to provide a control device.

B. Structure of the Invention (1) Means for Solving the Problems In the present invention, a first cylinder portion and a second cylinder portion are provided concentrically within the casing with a partition wall interposed therebetween, and the first cylinder portion includes: A first piston that defines an input hydraulic chamber on the partition wall side and defines the control chamber on the opposite side of the partition wall is slidably connected to the second cylinder portion, and defines an output hydraulic chamber on the partition wall side and A spring chamber is defined on the side opposite to the partition wall, and the first
A second piston having a larger diameter than the piston is slid together,
The first and second pistons are respectively fixed to both ends of a piston rod that fluidly and movably penetrates the partition wall, and the partition wall has a valve that closes in response to movement of the second piston away from the partition wall. An actuated valve mechanism is provided, and the spring chamber accommodates a spring that biases the second piston toward the partition wall.

(2) Effect According to the upper machine configuration, the hydraulic pressure in the input hydraulic chamber is proportionally reduced and transmitted to the output hydraulic chamber according to the difference in the hydraulic action areas of the first and second pistons, and the valve mechanism is proportionally reduced in pressure and transmitted to the output hydraulic chamber. It also functions as a pressure reducing valve, and since the braking hydraulic system is unified, it is easy to fill with hydraulic oil.

(3) Embodiment An embodiment of the present invention will be explained below with reference to the drawings. First, in FIG. 1, the master cylinder M
A casing 4 is provided between an oil passage 2 extending from an output port 1 of the vehicle and an oil passage 3 leading to a wheel brake B mounted on a wheel W. This casing 4
A valve mechanism 5 provided therein functions to proportionally reduce the braking hydraulic pressure from the master cylinder M when the brake is operated and transmit it to the wheel brakes B, and also acts as an anti-lock control means when the wheels W are about to enter a lock state. The valve is closed by the anti-lock control hydraulic pressure supplied from the master cylinder M and serves to cut off the supply of braking hydraulic pressure from the master cylinder M to the wheel brakes B.

A hole 7 with an open top and extending vertically is bored in the casing 4. A cylindrical partition member 8 with a bottom is inserted into the hole 7, and an O-ring 9 is inserted between it and the inner surface of the hole 7. It is inserted with an interposition. Moreover, the partition wall member 8
is inserted halfway into the hole 7 with its bottom as the partition wall 10 facing downward, and is supported by a stepped portion 11 provided halfway through the hole 7 facing upward. A cap 12 is screwed into the open end of the hole 7, and the cap 12 is tightened until it comes into contact with the open end of the partition member 8 and presses the partition member 8 against the stepped portion 11.
In this way, inside the casing 4, there is a lower first cylinder part 13 and an upper second cylinder part 14.
are provided concentrically with the partition wall 10 interposed therebetween.

A first piston 15 is slidably connected to the first cylinder portion 13 . An input hydraulic pressure chamber 16 is defined between the first piston 15 and the partition wall 10, and the input hydraulic pressure chamber 16 is communicated with the oil passage 2 via an inlet oil passage 17 bored in the side surface of the casing 4. Ru. Further, a control chamber 18 is defined by the first piston 15 and the end wall of the first cylinder portion 13 on the side opposite to the input hydraulic chamber 16 with respect to the first piston 15 .

A second piston 19 having a larger diameter than the first piston 15 is slidably connected to the second cylinder portion 14 . An output hydraulic pressure chamber 20 is defined between the second piston 19 and the partition wall 10, and the output hydraulic pressure chamber 20 is connected via an outlet oil passage 21 provided across the side wall of the partition member 8 and the casing 4. It communicates with the oil passage 3. Further, a spring chamber 22 open to the atmosphere is defined between the second piston 19 and the cap 12, and a spring biasing the second piston 19 toward the partition wall 10 is contained in the spring chamber 22. 23 is accommodated. Note that the spring chamber 22 is protected against the possibility that the first piston 15, second piston 19, and piston rod 25 move upward, or that air in the spring chamber 22 is sucked into the output hydraulic chamber 20 due to temperature changes or the like. If not,
It may be sealed.

The through hole 24 bored in the center of the partition wall 10 has a
A piston rod 25 is inserted through the piston rod 25 so as to be freely movable in the axial direction, and the first and second pistons 15 and 19 are fixed to both ends of the piston rod 25, respectively.
Furthermore, an O-ring 26 is fitted into the inner surface of the through hole 24 and is fitted into the input hydraulic chamber 16 through a gap between the outer surface of the piston rod 25 and the inner surface of the through hole 24. There is no communication between the output hydraulic chambers 20.

A valve mechanism 5 is provided in the partition wall 10 . The valve mechanism 5 includes a valve chamber 27 that communicates with the input hydraulic chamber 16 and is provided in the partition wall 10, a valve hole 28 that is provided between the valve chamber 27 and the output hydraulic chamber 20, and a valve hole 28 that opens and closes the valve chamber 27. A spherical valve body 29 is housed in the valve chamber 27, and a valve hole 28 is provided integrally with the valve body 29.
A drive rod 30 protrudes into the output hydraulic chamber 20 through the
and a spring 31 housed in the valve chamber 27 and urging the valve body 29 toward the valve hole 28 side. A conical valve seat 32 is provided on the end surface of the valve chamber 27 on the valve hole 28 side, the diameter of which decreases toward the valve hole 28 side. Further, the length of the drive rod 30 is such that the second piston 19 is
When the second piston 19 is maximally displaced toward the 0 side,
The pressure is set to a value sufficient to push the valve body 29 away from the valve seat 32.

The anti-lock control means 6 includes a hydraulic pump 36 that pumps control fluid, such as pressure oil, from the reservoir R.
A decompression source 3 consisting of an accumulator 37 and an accumulator 37
3, a first solenoid valve 34 that is closed during normal times, a second solenoid valve 35 that is open during normal times, and a warning signal or drive for the hydraulic pump 36 in the event of a failure of the hydraulic pressure source 36 or loss of control hydraulic pressure. A hydraulic switch 38 is provided for detecting start and stop.

The first solenoid valve 34 and the second solenoid valve 35 are connected to the valve box 3
9, and this valve box 39 is integrated into the casing 4. A first valve hole 40, a first valve chamber 41, a second valve hole 42, a second valve chamber 43, and an oil passage 44 are bored in the valve case 39 in this order from the bottom to the top. An oil passage 45 connected to the pressure source 33 is communicated with the first valve hole 40 via a supply oil passage 46 bored in the casing 4 . In addition, the oil passage 44 is a starting oil passage 4 bored in the casing 4.
7 to the reservoir R. The first solenoid valve 34 is housed in a first valve chamber 41 to open and close the first valve hole 40, and the first valve chamber 41 is located inside the casing 4.
It is communicated with the control room 18 via an oil passage 48 provided in the control room 18 . The second valve hole 42 also communicates with the first valve chamber 41, and the second solenoid valve 35 is housed in the second valve chamber 43 to open and close the second valve hole 42.

The first solenoid valve 34 is closed during normal times, and the second solenoid valve 35 is open during normal times. However, when a sensor (not shown) detects that the wheel W is about to enter a locked state, The solenoid valve 35 closes and the first
Solenoid valve 34 opens. Therefore, during normal times, control room 1
8 is in communication with the reservoir R, and when the wheels W are about to enter the lock state, anti-lock control hydraulic pressure from the hydraulic pressure source 33 is supplied to the control chamber 18.

Next, to explain the operation of this embodiment, when the brake pedal Bp is not operated and is not operated, the second piston 19 is displaced downward by the spring force of the spring 23 until it comes into contact with the partition wall 10, and the second piston 19 is displaced downward until it comes into contact with the partition wall 10, and 5, the drive rod 30 is connected to the second piston 1
9, the valve body 29 is separated from the valve seat 32 and opened. Therefore, from the output boat 1 of the master cylinder M to the oil passage 2, the inlet oil passage 17,
A hydraulic path leading to the wheel brake B is formed via the input hydraulic chamber 16, the valve chamber 27, the separate hole 28, the output hydraulic chamber 20, the outlet oil passage 21, and the oil passage 3. This makes it possible to extremely easily fill the hydraulic fluid in the brake hydraulic system in the same manner as in a brake hydraulic system that does not include the valve mechanism 5 for anti-lock control.
That is, whereas conventionally, the hydraulic path from the master cylinder M to the input hydraulic chamber 16 and the hydraulic path from the output hydraulic chamber 20 to the wheel brake B had to be separated and filled with hydraulic oil.
Since the braking hydraulic pressure path from the master cylinder M to the wheel brakes B is established, filling the hydraulic oil from the master cylinder M side completes the filling of the hydraulic oil up to the wheel brakes B. Moreover,
Inside the casing 4, the input hydraulic chamber 16 is located below the partition wall 10, and the output hydraulic chamber 20 is located above the partition wall 10, so hydraulic oil flows from the input hydraulic chamber 16 to the output hydraulic chamber 20 via the valve mechanism 5. Since the air flows upward, it becomes extremely easy to remove air.

Here, the set load of the spring 23 is F, the oil pressure of the input oil pressure chamber 16 is P ₁ , the oil pressure of the output oil pressure chamber 20 is P ₂ ,
The cross-sectional area of the first piston 15 is A ₁ , the cross-sectional area of the second piston 19 is A ₂ , and the cross-sectional area of the piston rod 25 is
A ₃ and the cross-sectional area of the valve hole 28 in the valve mechanism 5 are A ₄ .

When a brake operation is performed using the brake pedal Bp, the hydraulic pressure _P1 in the input hydraulic chamber 16 supplied from the output port 1 of the master cylinder M is initially supplied as is to the wheel brake B via the hydraulic path. Therefore, the oil pressure P ₂ of the output oil pressure chamber 20 is:
Initially, it is equal to the oil pressure P ₁ of the input oil pressure chamber 16 . The oil pressure P ₁ in the input oil pressure chamber 16 supplied from the output port 1 of the master cylinder M further increases, and the first piston 15, the second piston 19 and the piston rod 25
_{The vertical movement acting on the _ _}
When this occurs, the valve mechanism 5 is closed to limit the increase in the oil pressure _P2 . Furthermore, when the oil pressure P ₁ increases further, the valve mechanism 5 opens and closes with the relationship of P ₂ /P ₁ = (A ₁ −A ₃ −A ₄ )/(A ₂ −A ₃ −A ₄ ). Operate. here
Since A ₂ > A ₁ , the oil pressure P ₂ of the output oil pressure chamber 20 is
The pressure is reduced proportionally to the hydraulic pressure P ₁ A in the input hydraulic chamber 16.

To explain this using Fig. 2, F+P ₁ × (A ₁ − A ₃ − A ₄ )=P ₂ × (A ₂ − _{A 3} − A ₄ ) holds at point b, and between (a−b) Then, the oil pressures P ₂ and P ₁ are equal, and between (b and c), the oil pressure P ₂ is P ₂ /P ₁ = (A ₁ − _{A 3} − A ₄ ) / (A ₂ − _{A 3} − A ₄ ). The pressure is proportionally reduced in relation to

During brake operation, when the braking force becomes excessive and the wheels W are about to enter a lock state, the second solenoid valve 35 closes and the first solenoid valve 34 opens, so that anti-lock control from the hydraulic pressure source 33 is applied to the control chamber 18. Hydraulic pressure is supplied, and the first piston 15 is pushed upward against the downward force generated by the spring 23 and the hydraulic pressure of the input hydraulic chamber 16 . Along with this, the second piston 1
9 separates from the partition wall 10, the valve body 29 of the valve mechanism 5 seats on the valve seat 32 and closes, cutting off the supply of braking hydraulic pressure to the wheel brakes B. This prevents the wheels W from entering a locked state, but if the wheels are still likely to lock, the control fluid pressure in the control chamber 18 increases further, and the first
Piston 15 moves further upward. Therefore, the volume of the output hydraulic chamber 20 increases, the braking hydraulic pressure acting on the wheel brake B decreases, and the wheels W are reliably prevented from entering the locked state.

In this embodiment, the first and second solenoid valves 34,
Thirty-five valve boxes 39 are integrated into the casing 4, which allows the entire structure to be made compact.

C. Effects of the Invention As described above, according to the present invention, the first cylinder part and the second cylinder part are provided concentrically in the casing with the partition wall interposed therebetween, and the first cylinder part has an input hydraulic pressure on the partition wall side. a first piston that defines a chamber and defines a control chamber on the opposite side of the partition;
A second piston, which defines an output hydraulic chamber on the side of the partition wall and a spring chamber on the opposite side of the partition wall and has a larger diameter than the first piston, is slidably connected to the second cylinder part. The second piston is fixed to both ends of a piston rod that liquid-tightly and movably penetrates the partition wall, and the partition wall has a valve mechanism that closes the valve in response to movement of the second piston away from the partition wall. is provided, and the spring chamber accommodates a spring that biases the second piston toward the partition wall, so that the valve mechanism has an opening/closing function for anti-lock control;
It can function as a proportional pressure reducing valve, and the number of parts can be reduced, and accordingly, cost reduction, weight reduction, size reduction, and reliability improvement can be achieved. Furthermore, the oil passage or piping that was conventionally connected to the proportional pressure reducing valve is no longer necessary, allowing for a more rational layout. Further, since a hydraulic path is formed from the master cylinder to the wheel brakes when the anti-lock control means is not activated, the entire braking hydraulic system can be filled with hydraulic oil at once.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of an embodiment of the present invention,
FIG. 2 is a characteristic diagram of the proportional pressure reduction effect of the brake hydraulic pressure control device of the present invention. 1... Output port, 4... Casing, 5...
Valve mechanism, 6...Anti-lock control means, 10...
Partition wall, 13...first cylinder section, 14...second cylinder section, 15...second piston, 16...input hydraulic chamber, 18...control room, 19...second piston,
20... Output hydraulic chamber, 22... Spring chamber, 23...
Spring, 25... Piston rod, B... Wheel brake, M... Master cylinder, W... Wheel.

Claims (1)

[Claims] 1. An input hydraulic chamber communicating with the output port of the master cylinder, and an output hydraulic chamber communicating with the wheel brake and generating braking hydraulic pressure according to the hydraulic pressure in the input hydraulic chamber, and the wheels are in a locked state. In a vehicle brake hydraulic control device configured to increase the volume of an output hydraulic chamber in accordance with the supply of control hydraulic pressure from an anti-lock control means to a control chamber when a brake is about to enter the control chamber, a first cylinder portion is disposed within a casing. and a second cylinder section are provided concentrically through a partition wall, and the first cylinder section includes a first piston that defines an input hydraulic chamber on the partition wall side and defines the control chamber on the opposite side of the partition wall. are slid together, and a second piston that defines an output hydraulic chamber on the side of the partition wall and a spring chamber on the side opposite to the partition wall and has a larger diameter than the first piston is slid together in the second cylinder part, The first and second pistons are respectively fixed to both ends of a piston rod that fluidly and movably penetrates the partition wall, and the partition wall has a valve that closes in response to movement of the second piston away from the partition wall. A brake hydraulic control device for a vehicle, characterized in that an actuated valve mechanism is provided, and the spring chamber accommodates a spring that biases the second piston toward the partition wall. 2. The vehicle brake hydraulic control device according to claim 1, wherein within the cylinder, the output hydraulic pressure chamber is defined above the partition wall, and the input hydraulic pressure chamber is defined below the partition wall. .