JPS5836609Y2 - Hydraulic pressure control device for two-system control device - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a hydraulic pressure control device used in a dual-system hydraulic braking device for a vehicle.

Hydraulic braking systems for vehicles are designed to improve safety by dividing the piping system into two independent systems so that even if one system is damaged, the remaining system can stop the vehicle. There are many things.

Moreover, the reality is that so-called X piping, which connects the front left wheel and the rear right wheel, and the front right wheel and the rear left wheel, respectively, to one system of piping is increasing.

In addition, in vehicle braking systems, both the front and rear wheels do not lock during braking (the wheels stop rotating and slip between them and the road surface), and this is the most effective and safe way to operate the vehicle. For the purpose of stopping the vehicle, a proportioning valve is often inserted into the ring of the brake fluid passage that connects the mask cylinder and the rear wheel cylinder (hydraulic cylinder installed on the rear wheel).

The proportioning valve has an on-off valve that opens and closes the brake fluid passage, and one end surface is placed in an air chamber and is biased by a spring means in a direction to escape from the air chamber, and is normally in a position where the on-off valve is opened. and a control piston that moves toward the air chamber and starts opening/closing control of the on-off valve when the pressure in the brake fluid passage exceeds the set value, and the control piston moves in the direction toward the air chamber to start opening/closing control of the on-off valve, so that the pressure in the mask cylinder reaches the set value. This is a device that controls the pressure in the brake wheel cylinder to increase at a lower rate than the rate of increase in the master cylinder pressure when the pressure increases beyond the master cylinder pressure.

If this proportioning valve is to be attached to the aforementioned X pipe, two proportioning valves will of course be required.

When using a proportioning valve in dual-line piping, if one line of piping is damaged, the proportioning valve that is inserted into the other line's piping will be blocked or restrained from operating. It is common to either do this or bypass the proportioning valve.

Therefore, the hydraulic pressure control device in a braking device (hereinafter referred to as a rear wheel two-system control device) that transmits two independent systems of brake fluid pressure to the left and right rear wheel cylinders, such as the X piping, tends to be complicated, and there have been various types of Although it has been proposed, nothing satisfactory has been achieved yet.

With this background in mind, the present invention was developed with the aim of providing a hydraulic pressure control device for a two-system rear wheel control system with a structure as simple as possible and a shape that is easy to install.

To this end, the present invention has two proportioning valves disposed coaxially in a no-using state with a common air chamber, and (a) extends across the shared air chamber in the direction of movement of the control piston. It is movable in the right angle direction, receives the pressure of each of the two piping systems on the pressure receiving surfaces at both ends, and has a circumferential annular notch wider than the diameter of the air chamber side end of the control piston in the middle part. (b) positioning the lock piston in an intermediate position, typically such that the annular notch mates with the air chamber ends of the two control pistons to permit movement of the control pistons toward the air chamber; On the other hand, if the pressure in either of the two piping systems becomes lower than the pressure in the other system by a predetermined value, the system with the lower pressure becomes one of the two piping systems. However, in order to prevent the control piston from moving toward the air chamber, a lock piston positioning device is provided that allows the lock piston to move toward the pressure receiving surface that receives the lower pressure. This is a characteristic feature.

Embodiments will be described in further detail below based on drawings showing examples.

In FIG. 1, 1 is a mask cylinder.

By operating the brake pedal 2, two systems of working hydraulic pressure are generated independently in the first and second pressurizing chambers A and B.

The hydraulic pressure generated in the first pressurizing chamber A is led to the wheel cylinder 4L of the left front wheel through a pipe line 3, and is also led to the liquid control device 20 through a pipe line 9, and then to the right rear wheel cylinder through a pipe line 9. is guided to the wheel cylinder 5R.

This system will be referred to as the first system.

Further, the hydraulic pressure generated in the second pressurizing chamber B is similarly guided to the wheel cylinder 4R of the right front wheel and the wheel cylinder 5L of the left rear wheel through the pipes 6, 7, and 8.

This system will be referred to as the second system.

In other words, the piping in this embodiment is an X piping.

The hydraulic pressure control device 20 is composed of first and second proponents PVa, PVb and a locking mechanism R, and is housed as a whole in one elongated Ujifugu 15.

The first propioning valve PVa is slidably held by the housing 15 and has one end surface 1.
6a is provided with a control piston 18a disposed in an air chamber 17a.

A valve element 19a is fixed to the end of the control piston 18a opposite to the one that is housed in the air chamber T7a. 21a.

The control piston 18a is normally urged by the compression spring 22a in the direction of leaving the air chamber 17a.
The brake fluid passage leading to 4a is in communication.

The second proportioning valve Pvb has exactly the same structure as the first proportioning valve PVa described above, so the numbers are the same, for example, the control piston 18a is called the control piston 18b, but the code is changed from a to b. The same parts are indicated by , and detailed explanations are omitted.

2nd Proportioning Valve PVa.

As is clear from the figure, Pvb is the air chamber 17a.

17b continuously form one air chamber, and that one air chamber is connected to two proportioning valves PVa and PVb.
are arranged coaxially in a shared state, and a locking mechanism R is provided perpendicularly to these.

The lock mechanism R locks the proportioning valves PVa, P when either the first or second piping system is damaged.
It prevents the hydraulic pressure control operation of Vb, and is provided with a lock piston 25 for this purpose.

The locking piston 25 traverses said shared air chamber by the housing 15 and the control piston 18 a ,
The control piston 1 is held movably in a direction perpendicular to the direction of movement of the piston 18 b, and is provided with a control piston 1 at the intermediate portion in the longitudinal direction.
larger than the diameter of the ends 16a, 16b of 8a, 18b;
It is provided with an annular notch 26 having a width sufficient to allow insertion of both.

In this embodiment, the annular cutout 26 also serves as the air chambers 17a and 17b.

Also, a small diameter portion 2 formed at one end of the lock piston 25
7 is slidably fitted to the annular member 28 which is slidably fitted to the housing 15, and the annular member 28
The pressure receiving area S1 and the pressure receiving areas S2 and S3 on both sides of the lock piston 25 are set as Sl>Sl>S3.

Therefore, when both the first and second piping systems are normal, the annular member 28 is
- The lock piston 25 is held in the intermediate position shown in the figure by being brought into contact with the 150 step surface of the lock screw 1, and the 250 step surface of the lock screw 1 is brought into contact with the ring member, and the control pistons 18a, 18b are held at the intermediate position shown in the figure. However, one of the systems is damaged and the pressure difference between the two systems becomes a constant value (pressure receiving area S1.Sl).

(determined by the difference in S3), the control piston end 16a moves toward the left or right in the figure.

16b to prevent (lock) its movement.

That is, in this embodiment, the lock piston positioning device is constituted by the annular member 28, the stepped surfaces of the housing 15 and the lock piston 25 that come into contact with the annular member 28, the seals 31, 32, and the like.

Hey, in the diagram, 30a and 30b are seals, and 33a t
33b and 34 are plugs.

Next, the operation of this embodiment will be explained.

When brake pedal 2 is depressed, master cylinder 1
The brake fluid pressure in the pressurizing chamber A is led to the wheel cylinder 4L of the left front wheel through a pipe 3, and is also led to a hydraulic pressure control device 20 through a pipe 10.

The brake fluid pressure in the pressurizing chamber B is led to the wheel cylinder 4R of the right front wheel through a pipe 6, and is also led to the hydraulic pressure control device 20 through a pipe 7.

While this hydraulic pressure is relatively low, the control piston 18a.

18b valves 19a, 19b are valve seats) 20a.

The on-off valves 21a and 21b are open and are spaced apart from 20b, and at this point, the front wheel cylinders 4L,
4R and the rear wheel cylinders 5L and 5R, to which the brake hydraulic pressure of the hydraulic pressure control device 20 is guided by the pipes 8 and 9, the same brake hydraulic pressure as that of the mask cylinder 1 is guided.

However, the pressure in mask cylinder 1 increases and
When the hydraulic pressure applied to a, 23b exceeds a set value, the control pistons 18a, 1sb are activated by the compression springs 22a, 22b.
end 16a against the action of b.

16b is fitted into the annular notch 26, and the on-off valve 21a
, 21b to initiate well-known hydraulic control operations.

At this time, if both systems are normal, lock piston 2
5 is kept in an intermediate position.

As a result, the rear wheel cylinder 5L. The brake fluid pressure guided to 5R is increased at a lower rate of increase than the fluid pressure generated in the mask cylinder 1,
The most effective and safe way to stop the vehicle is to prevent both the front and rear wheels from locking during braking.

The above is an explanation of the operation when both systems are normal.1 For example, if the first system is damaged, the lock piston 25 is moved to the left in the figure, and the control piston 18b of the second system is moved to the left. Since the portion 16b cannot fit into the annular notch 26 of the lock piston 25, the control piston 18
b is held at the position shown in the figure, and the hydraulic pressure control operation of the proportioning valve Pvb is blocked.

Therefore, even if the liquid applied to the port 23b rises above the set value, the on-off valve 21b remains open, and the braking liquid pressure of the mask cylinder 1 applied to the port 23b is not reduced. 24b through the conduit 8 to the rear left and right wheel cylinders 5L, sufficient braking force can be obtained using only the second system.

At this time, the damaged control piston 18a of the first system is also locked, but the control piston 18a may or may not be locked.

On the other hand, if the second system is damaged, the lock piston 2
5 is moved rightward in the figure, the end 16a of the first system control piston 18a cannot fit into the annular notch 26 of the lock piston 25, and the Yahari proportioning valve PVaO hydraulic pressure control operation is blocked.

The embodiments of the present invention are not limited to the above-mentioned examples.Example: Flow portioning valve 7'' PVa.

Pvb can change this to one with a poppet valve type on-off valve.

Furthermore, lock mechanisms R for blocking the hydraulic pressure control operation of the proportioning valve are located on both sides of the lock piston 25' as shown in FIG.

A compression spring 39 is precompressed and installed between a first spring seat 37 that is fixed to the rod 36 and a second spring seat 38 that is movably attached to the rod 36 in only one direction. spring device 35a.

35b may be provided to convert it into a locking mechanism R' functioning as a locking piston positioning device.

According to the above lock mechanisms R, R', the lock piston 2
5, 25' are positioned and held in the intermediate position extremely accurately, and the lock piston does not move from the intermediate position even if there is a slight difference in pressure between the two piping systems. The width of the annular notch 26 is controlled by the piston 18a.

It is possible to reliably allow the control pistons 18a, 18b to fit therein by making the diameter only slightly larger than the diameter of the piston 18b.

Therefore, if either system is damaged, the amount of movement of the lock pistons 25, 25' will be minimal, and the amount of brake fluid required to operate the lock pistons 25, 25' can be reduced. becomes.

As described in detail above, the hydraulic pressure control device according to the present invention has an extremely simple structure consisting of two proportioning valves and one lock piston that locks the operation of both pulps. In addition to carrying out a predetermined hydraulic pressure control operation, when either one of the two piping systems is damaged, the hydraulic control operation of the system that is not damaged is blocked, and the brake is applied by this system. The rear wheels can be braked by the hydraulic pressure of the mask cylinder itself, and can be widely applied as a hydraulic pressure control device in a two-system rear wheel control system.

Furthermore, since the two proportioning valves are coaxially arranged and the lock piston is shared by both control pistons, the piping is simpler than when each proportioning valve K - lock piston is provided. A certain effect arose.

In the past, when the pressure difference between the two piping systems acting on the pressure-receiving surfaces at both ends of the lock piston exceeded a certain value, the lock piston was held stationary at an intermediate position by a lock piston positioning device, so a proportioning valve was used. It has become possible to set the amount of movement of the lock piston to an extremely small value to prevent the operation of the system, and it has become possible to reduce the amount of braking fluid consumed by the lock mechanism in the event of system failure.

Furthermore, the lock piston has one annular notch that allows the hydraulic pressure control operation of the two control pistons.
The shape is simple and no rotation prevention means are required.
It became possible for Yasushi to produce it.

Moreover, since the entire hydraulic pressure control device can be made into an elongated shape,
This makes it easy to install it in long and narrow spaces such as inside the chassis frame.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view showing one embodiment of the present invention, and FIG. 2 is a cross-sectional view of essential parts showing a locking mechanism in another embodiment of the present invention. 1...Mask cylinder %2...Brake hetal, 3
゜6, γ, 8, 9, 10... Pipeline, 4L, 4R, 5L
. 5R...Wheel cylinder, 15...Housing. ? 6a, 16b... Control piston end, 26° (I
Ta, 1 rb) ---I-shaped notch (air chamber), 1
8at18b...control piston, 19at19b...
・Valve, 20a, 20b... Valve seat, 21a,
21b...Opening/closing valve, 22a, 22b...Compression spring,
23a. 23b, 24a, 24b...port, 25, 25'
-...Lock piston, PVa, PVb...Proportioning valve, R, R'...Lock mechanism, 3
5 a. 35b... Spring device.

Claims (1)

[Claim for Utility Model Registration] Two independent pipes that transmit the braking fluid pressure generated in the independent correction chamber at the tail of the mask cylinder to the respective rear wheel cylinders arranged on the left and right rear wheels. A hydraulic pressure control device for use in a vehicle hydraulic brake system equipped with a hydraulic brake system, comprising an on-off valve for opening and closing each brake fluid passage of the two piping systems, and a spring means having one end facing an air chamber. The on-off valve is normally in a position where it is biased in a direction to escape from the air chamber, and when the pressure in the brake fluid passage exceeds a set value, it moves toward the air chamber and closes the on-off valve. a control piston that closes the mask cylinder, and a hydraulic control operation that increases the pressure of the rear wheel cylinder at a rate lower than the rate of increase of the mask cylinder pressure when the pressure of the master cylinder increases beyond a set value. two proportioning valves disposed coaxially sharing the air chamber, and (a) movable across the seven shared air chambers in a direction perpendicular to the direction of movement of the control piston; , a lock piston that receives the respective pressures of the two piping systems on its pressure receiving surfaces at both ends, and has an annular notch in the circumferential direction that is wider than the diameter of the air chamber side end of the control piston in the middle part; (b) positioning the locking piston at an intermediate position where the annular notch normally coincides with the air chamber side ends of the two control pistons to permit movement of the control pistons toward the air chamber; While holding the pressure, if the pressure in either of the two piping systems becomes lower than the pressure in the other system by a predetermined value or more, the system in which the pressure has become lower is one of the two piping systems. and a lock piston positioning device that allows the lock piston to move toward the pressure receiving surface receiving the lower pressure in order to prevent the control piston from moving toward the air chamber. A hydraulic control device for a two-system control device characterized by the following.