JPH0215414B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION According to the present invention, when the output hydraulic pressure of the master cylinder transmitted to the rear wheel brake exceeds a predetermined value, the output hydraulic pressure is reduced at a fixed ratio and transmitted to the rear wheel brake. Vehicle brake hydraulic control system, especially
A housing is interposed in the flow path connecting the output port of the master cylinder and the hydraulic operating part of the rear wheel brake, and a pressure receiving piston is slid into the cylinder hole in the housing, and the pressure receiving piston is attached to one end side of the pressure receiving piston. An input hydraulic chamber communicating with the upstream side of the flow path and an output hydraulic chamber communicating with the downstream side of the flow path are formed at the other end, and the pressure receiving area of the output hydraulic chamber side of the pressure receiving piston is defined as the input hydraulic pressure chamber side. The valve seat is formed at the opening end of the input hydraulic chamber of the communication hole provided in the pressure receiving piston to communicate between the input and output hydraulic chambers, and the valve seat is larger than the pressure receiving area of the pressure receiving piston. The present invention relates to a poppet-type valve that opens and closes the communication hole in cooperation with a seat and is disposed in the input hydraulic chamber.

Conventionally, in such devices, the valve seat is made of a valve seat alloy separate from the pressure-receiving piston in order to prevent dents from occurring on the contact surface between the valve and the valve seat and deteriorating the sealing performance. was forming.

However, such a configuration not only complicates the structure but also increases costs.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a brake hydraulic control device that has a simple structure and can withstand long-term use.

In order to achieve this object, the present invention integrally forms a conical valve seat on the pressure receiving piston, configures the valve from a hard material having a lower hardness than the pressure receiving piston, and provides the valve seat of the valve. It is characterized by having a seating surface formed into a spherical convex surface.

Conventionally, in such devices, the pressure-receiving piston and the valve that can be seated on the valve seat formed therein have been constructed of the same metal. This has the disadvantage that dents are formed on the brake pad, resulting in poor sealing performance, and the control characteristics of the braking oil pressure are disturbed to some extent.

It is an object of the present invention to provide the braking hydraulic pressure control device free from such drawbacks, and in which the valve is made of a material having a lower hardness than the pressure receiving piston and has a poppet shape, so that the valve has an umbrella shape. disposing a valve head in the input hydraulic chamber, passing a valve rod through the communication hole and abutting against an inner wall of the housing, and forming a conical valve seat at an opening of the communication hole to the input hydraulic chamber; The valve head is characterized in that the seating surface of the valve head relative to the valve seat is formed into a spherical convex surface.

Hereinafter, one embodiment of the present invention will be described with reference to the drawings. In FIG. 1, front and rear wheel brakes Bf, Br' and Bf are arranged diagonally to each other and form a
First and second flow paths L ₁ and L ₂ which are independent of each other and extend from the output side of the dual master cylinder M are connected to the hydraulic operation part of the BR and Br, respectively.
A brake hydraulic control device C of the present invention is provided between L ₁ and L ₂ and the rear wheel brakes Br and Br'.

The above master cylinder M and brake hydraulic control device C
will be explained in detail with reference to FIGS. 2 and 3.

First, the double master cylinder M is configured in a tandem type, and when the brake pedal 1 is operated, a pair of front and rear pistons 2 ₁ and 2 ₂ in the cylinder are connected to the first and second output ports P ₁ and P ₂ respectively. Pressure oil can be supplied from the flow path to the first and second flow paths L ₁ and L ₂ . This pressure oil is led to the front wheel brakes Bf, Bf' and the brake hydraulic control device C.

The brake hydraulic control device C is configured symmetrically, and its left and right housings 3 ₁ and 3 ₂ are joined to each other by bolts 5 and nuts 6 via flanges 4 ₁ and 4 ₂ . In the housings 3 ₁ and 3 ₂ ,
Cylinder holes 7 ₁ , 7 ₂ and a larger diameter hole 8
₁ , 8 ₂ are formed, and each cylinder hole 7 ₁ ,
Pressure-receiving pistons 9 ₁ and 9 ₂ having the same diameter are respectively slid onto 7 ₂ , and a minimum distance necessary for the operation of each pressure-receiving piston is provided between the pressure-receiving pistons 9 ₁ and 9 ₂ . Small cylinder holes 10 _{1 , 10 2 having the same diameter are formed in each of the pressure receiving pistons 9 1 , 9 2} , and valve moving pistons 11 , whose back surfaces abut each other, are formed in these small cylinder holes 10 ₁ , 10 _{2 . 1} ,11 ₂
are in sliding contact with each other.

In the large diameter holes 8 ₁ , 8 ₂ , both pressure receiving pistons 9 ₁ ,
Shoulder portion 31 opposite to the outer periphery of the axially intermediate portion of 9 _2
1 and 31 ₂ are formed, and a common relatively strong coiled pressure regulating spring 12 is compressed between these shoulders 31 ₁ and 31 ₂ via washers 32 ₁ and 32 ₂ that abut against them.

Further, between the two valve moving pistons 11 ₁ and 11 ₂ , shoulder portions 13 ₁ and 13 ₂ of each piston 11 ₁ and 11 ₂ are provided.
and the inner and outer shoulder portions 1 of the small cylinder holes 10 ₁ and 10 ₂
A relatively weak coil-shaped positioning spring 17 is compressed through washers 16 ₁ and 16 ₂ that can abut on _{4 1} and 14 ₂ and 15 1 and 15 ₂ , respectively.

First and second input hydraulic chambers 18 ₁ , 18 ₂ are connected to the outer ends of the valve moving pistons 11 ₁ , 11 ₂ in both small cylinder holes 10 ₁ , 10 ₂ , and both cylinder holes 7 ₁ , 7 ₂ includes pressure receiving pistons 9 ₁ , 9 ₂
The first and second output hydraulic chambers 19 ₁ ,
19 ₂ are respectively defined, and these first and second input hydraulic chambers 18 ₁ , 18 ₂ have inflow ports 20 ₁ ,
Upstream of the first and second flow paths L ₁ , L ₂ via 20 ₂ are also connected to the first and second output hydraulic chambers 19 ₁ , 1
9 ₂ has both flow paths via outflow ports 21 ₁ and 21 ₂
The downstream sides of L ₁ and L ₂ are connected so that they are always in communication with each other.

The end walls of the small cylinder holes 10 ₁ and 10 ₂ are provided between adjacent input and output hydraulic chambers 18 ₁ and 19 ₁ and between the adjacent input and output hydraulic chambers 18 1 and 18 ₂ , 1
Communication holes 22 ₁ and 22 ₂ are provided to communicate between the pressure receiving pistons 9 ₁ and 9 ₂ , respectively, and a valve V is provided to open and close the communication holes 22 1 and 22 ₂ in accordance with the reciprocating sliding movement of the pressure receiving pistons 9 ₁ and 9 ₂ . ₁ and _V2 are provided as follows.

The valves V ₁ and V ₂ are made of a hard material having a lower hardness than the pressure receiving pistons 9 ₁ and 9 ₂ and are configured in a poppet shape. For example, when the pressure receiving pistons 9 ₁ and 9 ₂ are made of iron, the valves V ₁ and V ₂ are suitably made of phenol resin.

Umbrella-shaped valve heads 23 ₁ , _{2 of poppet-type valves V 1 ,} V 2
3 ₂ are arranged in the input hydraulic chambers 18 ₁ , 18 ₂ , and their valve rods 24 ₁ , 24 ₂ are connected to communication holes 22 ₁ , 22 _{2 .}
and the valve rod 24 ₁ ,
The tips of 24 ₂ come into contact with the end walls of cylinder holes 7 ₁ and 7 ₂ , that is, the inner walls of housings 3 ₁ and 3 ₂ .

Input hydraulic chambers 18 ₁ , 18 ₂ of communication holes 22 ₁ , 22 ₂
Conical valve seats 33 ₁ , 33 ₂ are formed at the openings to the valve seats 33 ₁ , 33 ₂ , and the seating surfaces of the valve heads 23 1 , 23 2 relative to these valve seats 33 ₁ , 33 ₂ are formed into spherical convex surfaces a.

In addition, the tip surfaces of the valve rods 24 ₁ and 24 ₂ are spherical convex surfaces b
On the other hand, the contact surfaces of the inner walls of the housings 3 ₁ and 3 ₂ with the valve rods 24 ₁ and 24 ₂ are formed into spherical convex surfaces c having a larger radius than the spherical convex surfaces b, and the center of this spherical convex surface c is It is arranged on the axis of the communicating holes 22 ₁ and 22 ₂ .

Each valve V ₁ , V ₂ and valve moving piston 11 ₁ ,
Closing springs _{25 1 and} 25 ₂ are respectively contracted between the valves V ₁ and V ₂ , and normally the tips of the valve rods 24 ₁ and 24 ₂ of the valves V 1 and V 2 are connected to the spherical inner walls of the housings 3 ₁ and 3 ₂ . In contact with the convex surface c, each pressure receiving piston 9 ₁ , 9 ₂
The valves V ₁ and V ₂ are held in the open position at the outward sliding limit of . The pressure receiving pistons 9 ₁ , 9 ₂ move inward, and the valve heads 23 ₁ , ₉ 2 are attached to the valve seats 33 1 , 33 ₂ .
When 23 ₂ is seated, the communication holes 22 ₁ and 22 ₂ are closed.

Connectors 26 ₁ and 26 ₂ are attached to the inner ends of the valves V ₁ and V ₂ , respectively. The inner ends of these connectors 26 ₁ , 26 ₂ are connected to stoppers provided at the outer ends of the valve moving pistons 11 ₁ , 11 ₂ when the pistons 11 ₁ , 11 ₂ move inward by a predetermined distance l ₂ . 27 ₁ and 27 ₂ . This distance l ₂ is the distance between the pressure receiving pistons 9 ₁ and 9 ₂ from the open position to the closed position of the valves V ₁ and V ₂ .
is larger than the distance l ₁ that moves, and this distance l ₁ and the washer 16 ₁ , 1 with respect to the small cylinder holes 10 ₁ , 10 ₂
6 ₂ is smaller than the sum of the distance l ₃ that can be moved.

A small hole 28 communicating with the outside is provided at the joint between the housings 3 ₁ and 3 ₂ , and a seal ring 29 is provided inside this joint to prevent dust from entering from the outside. . This seal ring 29 allows hydraulic oil etc. to flow from the inside to the outside, and seal members 30 ₁ , 30 ₂ between the pressure receiving pistons 9 ₁ , 9 ₂ and the cylinder holes ₇ 1 , 7 _{2 .}
If the hydraulic oil leaks into the large-diameter holes 8 ₁ and 8 ₂ due to wear and damage, the hydraulic oil will flow out through the seal ring 29 and the small hole 28, and the failure will be solved by removing the oil in the reservoir of the master cylinder M. This makes it possible to detect abnormal surface deterioration.

Next, the operation of this embodiment will be explained.
When the master cylinder M is not in operation, both the left and right pressure receiving pistons 9 ₁ and 9 ₂ are pressed to the outward sliding limit shown in the figure by the spring force of the pressure regulating spring 12 and the positioning spring 17, and the valves V ₁ and V ₂ are Each valve is open, and the first and second input and output hydraulic chambers 18 ₁ and 19 ₁ and between 18 ₂ and 19 ₂ are in communication with each other.
Therefore, when the brake pedal 1 is operated here, the output hydraulic pressure of the master cylinder M changes to the first and second hydraulic pressures.
It is transmitted to each downstream of the flow paths L ₁ and L ₂ , and the front and rear wheel brakes Bf, Bf' and Br, Br' are operated simultaneously.

Then, as the output oil pressure of the master cylinder M increases, the first and second input and output oil pressure chambers 18 ₁ , 19 ₁
The pressure inside the pressure receiving pistons 9 ₁ , 19 ₂ also rises, but when the pressure reaches a certain value, the difference in the pressure receiving areas between the inner and outer ends of the pressure receiving pistons 9 ₁ , 9 _{2 increases} .
The differential hydraulic pressure acting on the pressure regulating _{spring 12} and the positioning spring 17 becomes larger than the set load of the pressure regulating spring 12 and the positioning spring 17, and the pressure receiving pistons ₉₁ and ₉₂ slide inward while compressing the pressure regulating spring 12 and the positioning spring, respectively. do. on the other hand,
At this time, since substantially equal oil pressure is applied to the outer ends of each valve moving piston 11 ₁ , 11 ₂ , these pistons 11 ₁ , 11 ₂ do not move.
Each valve V ₁ , V ₂ is pressed outward by the closing spring 25 ₁ , 25 ₂ , and the valve rod 24 ₁ , 24 ₂ is closed by the housing 3
₁ and 3 maintain the state in contact with the spherical convex surface c of ₂ .
Therefore, when each pressure receiving piston 9 ₁ , 9 ₂ moves inward by a distance l ₁ , the valve head 2 of the valve V ₁ , V ₂
Seated at 3 ₁ , 23 ₂ . Therefore, bento 23 ₁ , 2
3 ₂ has a lower hardness than the pressure-receiving pistons 9 ₁ and 9 ₂ , so it exhibits a damping effect and does not damage the valve seats 33 ₁ and 33 ₂ even after long-term use. In addition, the spherical convex surfaces a of the valve heads 23 ₁ and 23 ₂ and the conical valve seat 33 ₁ ,
33 ₂ , a self-aligning action is exerted on the valve heads 23 ₁ and 23 ₂ , and this self-aligning action is caused by the engagement with the valve rod 24.
This is further promoted by the engagement between the spherical convex surfaces b of ₁ and 24 ₂ " and the spherical convex surfaces c of the housings 3 ₁ and 3 ₂ .

Thus, the valve heads 23 ₁ , 23 ₂ and the valve seats 33 ₁ , 3
The sealing performance between 3 ₂ is good, and the communication holes 22 ₁ , 2
2 ₂ is definitely closed. During this time, the brake oil pressure for the rear wheels does not increase.

When the output hydraulic pressure of the master cylinder M further increases, the pressure within the input hydraulic chambers 18 ₁ and 18 ₂ increases, pushing each pressure receiving piston 9 ₁ and 9 ₂ outward.
Therefore, the valves V ₁ , V ₂ open again, increasing the pressure in the output hydraulic chambers 19 ₁ , 19 ₂ . When this pressure reaches a certain value, the pressure receiving pistons 9 ₁ and 9 ₂ operate again, and the communication holes 22 ₁ and 22 ₂ are closed.
Stop that pressure from increasing. By repeating these actions, the braking oil pressure for each rear wheel gradually increases.

On the other hand, since the output hydraulic pressure of the master cylinder M directly acts on the front wheel brakes Bf, Bf', the front wheel braking hydraulic pressure increases rapidly as the output hydraulic pressure of the master cylinder M increases. In this way, when braking is applied strongly, the front wheel brakes Bf and Bf' are applied more strongly to the front wheel on the side where the vehicle body leans forward and the downward load increases.
Rear brake for the rear wheel on the side where the load is reduced
Since Br and Br' are operated weakly, efficient braking can be performed without causing skids in each wheel.

Next, if one of the control hydraulic circuits, for example the second flow path _L2 side, breaks down, the rear wheel brake
Suppose that braking hydraulic pressure is no longer applied to the hydraulic operating part of Br′. At this time, when the brake pedal 1 is operated, the output oil pressure of the master cylinder M is changed to the first flow path _L1.
The pressure in the first input hydraulic pressure chamber 18 ₁ increases, but the pressure in the second input hydraulic pressure chamber 18 ₂ does not increase. Therefore, both the valve moving pistons 11 ₁ and 11 ₂ move rightward in the figure, and the washer 16 ₁ engages with the inner shoulder 14 ₁ of the small cylinder hole 10 ₁ . Then, the valve moving cylinder 11 ₁ moves the pressure receiving piston 9 ₁ inward. When the valve moving piston ₁₁₁ moves by a predetermined distance _l2 ,
The stopper 27 ₁ at its outer end engages the inner end of the connector 26 ₁ and moves the valve V ₁ inwardly. distance l ₂
is smaller than l ₁ + l ₃ , so during this period the valve
V ₁ is away from the end wall of the small cylinder hole 10 ₁ ,
The valve remains open. In this way, the valve moving piston 11 ₁ , the pressure receiving piston 9 ₁ , and the valve V ₁
moves inward to a position where the inner end of the pressure receiving piston 9 ₁ abuts the inner end of the other pressure receiving piston 9 ₂ .

When the pressure receiving pistons 9 ₁ and 9 ₂ are in contact with each other, the valve moving piston 11 ₁ is pressed inward by the hydraulic pressure in the first input hydraulic pressure chamber 18 ₁ .
Washer 16 ₁ is inside shoulder _{14 1} of small cylinder hole 10 1
The stopper 27 ₁ of the valve moving piston 11 ₁ remains engaged with the inner end of the connector 26 ₁ . Therefore, at this time, the valve V ₁ opens the communication hole 22 ₁ . As a result, the output hydraulic pressure of the master cylinder M is directly transmitted to the first output hydraulic pressure chamber ₁₉₁ , and
The front and rear brakes Bf ₁ and Br of the flow path L ₁ operate with the same strength. That is, this brake hydraulic control device C is provided with a bypass function.

In addition, in the above embodiment, the valve moving pistons 11 ₁ and 11 ₂ are configured as separate bodies, but
If there is no problem with processing accuracy, these can be integrated.

As described above, according to the present invention, a conical valve seat is integrally formed on the pressure receiving piston, the valve is made of a hard material having a lower hardness than that of the pressure receiving piston, and the valve is seated on the valve seat. Since the surface is formed into a spherical convex surface, the structure can be simplified by integrating the pressure receiving piston and the valve seat, which can contribute to cost reduction. Moreover, when the valve is opened, its damper action prevents damage to the valve and valve seat, and the engagement between the conical valve seat and the spherical convex surface provides a self-aligning action to the valve, and the communication hole Therefore, the valve seat can withstand long-term use without having to make the valve seat from a special valve seat alloy, and can always exhibit stable braking oil pressure control characteristics. .

[Brief explanation of drawings]

FIG. 1 is a system diagram of a braking system for an automobile equipped with the device of the present invention, FIG. 2 is a longitudinal sectional plan view of an embodiment of the device of the present invention, and FIG. 3 is an enlarged view of the main parts thereof. Br, Br'...Rear wheel brake, C...Brake hydraulic control device, _L1 , _L2 ...Flow path, M...Master cylinder, _V1 , _V2 ...Valve, a...Seating surface, 9 _1,9
2 ... Pressure receiving piston, 18 ₁ , 18 ₂ ... Input hydraulic chamber, 19 ₁ , 19 ₂ ... Output hydraulic chamber, 22 ₁ , 22 ₂
... Communication hole, 23 ₁ , 23 ₂ ... Valve head, 24 ₁ , 2
4 ₂ ... valve lever, 33 ₁ , 33 ₂ ... valve seat.

Claims (1)

[Claims] 1. Flow paths L 1 , L ₂ connecting the output port of the master cylinder M and the hydraulic operating parts of the rear wheel brakes Br, Br _' .
The housings 3 ₁ , 3 ₂ are interposed in the housings 3 ₁ , 3 ₂ , and the pressure receiving pistons _{9 1} , 9 ₂ are slid into the cylinder holes 7 1 , 7 ₂ in the housings _{3 1} , 3 ₂ .
The input hydraulic chambers 18 1 and 18 2 are connected to the upstream side of the flow paths L ₁ and L ₂ on one end side, and the output oil pressure chambers 18 ₁ and 18 ₂ are connected to the downstream side of the flow paths L ₁ and L ₂ on the other end side. 19 ₁ ,
19 ₂ respectively, and the pressure receiving pistons 9 ₁ ,
The pressure receiving area of the output hydraulic chambers 19 _{1 ,} 19 ₂ of 9 2 is made larger than the pressure receiving area of the input hydraulic chambers 18 ₁ , 18 ₂ , and the pressure receiving pistons 9 ₁ , 9 ₂ are arranged to communicate between the input and output hydraulic chambers. The opening ends of the communication holes 22 ₁ , 22 ₂ on the input hydraulic chambers 18 ₁ , 18 ₂ are formed in the valve seats 33 ₁ , 33 ₂ , and the valve seats 33 1 , 33 2 respond to the reciprocating sliding movement of the pressure receiving pistons 9 ₁ , 9 ₂ . a poppet-type valve V ₁ that opens and closes the communication holes 22 ₁ and 22 ₂ in cooperation with the seats 33 ₁ and 33 ₂ ;
In the braking hydraulic control device for a vehicle in which V ₂ is disposed in the input hydraulic chambers 18 ₁ and 18 ₂ , a conical valve seat 33 is provided in the pressure receiving pistons 9 ₁ and 9 ₂ .
₁ , 33 ₂ are integrally formed, and this pressure receiving piston 9 ₁ ,
9. The valve is made of a hard material with a hardness lower than ₂ .
A braking hydraulic control device for a vehicle, comprising valves V _{1 and V 2 ,} and seating surfaces a for the valve seats 33 ₁ and 33 ₂ of the valves V 1 and V 2 are formed as spherical convex surfaces. 2. In what is stated in claim 1,
The pressure receiving piston is made of iron-based material, and the valve is made of phenolic resin.
Vehicle brake hydraulic control device.