JPH0640531Y2 - Proportioning valve for vehicle braking - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION a. Field of Industrial Application The present invention relates to a proportioning valve for vehicle braking.

b. Prior Art FIGS. 9 and 10 show a conventional proportioning valve.

In this proportioning valve 1, the fluid supplied from the master cylinder or the like into the valve housing 3 through the input port 2 is, as shown by the solid arrow in FIG.
It is fed to the output port 6 through the space between the piston 4 and the seal member 5, and is further fed under pressure to the wheel cylinder of the wheel or the like. Then, when the pressure of the output port 6 exceeds a certain pressure, the differential pressure acting on the plunger 4 causes the plunger 4
Is actuated against the urging force of the spring 7, and the valve body portion 4a of the plunger 4 contacts the seal member 5 to disconnect the input port 2 from the output port 6. When the pressure in the input port 2 further increases, the valve body 4a of the plunger 4 is separated from the seal member 5 again, and the fluid on the input port 2 side is pumped to the output port 6 side. Then, when the pressure on the output port 6 side with respect to the pressure on the input port 2 side reaches a constant value, the valve body portion 4a of the plunger 4 contacts the seal member 5,
The input port 2 and the output port 6 are cut off again. The proportioning valve 1 repeats such operation,
The oil liquid in the master cylinder, etc. is decompressed at a fixed ratio and supplied to the wheel cylinders of the wheels.

On the other hand, in this proportioning valve 1, when the pressure on the input port 2 side decreases, for example, when braking is released, the valve body portion 4a of the plunger 4 is kept in contact with the seal member 5, so that the output The oil liquid on the port 6 side is the 10th
The lip portion 5a of the seal member 5 is pushed away and returned to the input port 2 side through a path shown by a dotted arrow in the figure.

c. Problem to be solved by the invention By the way, when such a proportioning valve 1 is adopted in the braking system of a vehicle, the plunger valve is used especially in a state where a large amount of oil liquid is flowing through the proportioning valve 1 during sudden braking. When 4 is actuated and the space between the valve body 4a and the seal member 5 is narrowed, abnormal noise may be generated.

In order to prevent the generation of this abnormal noise, a fixed throttle may be provided in the braking system to control the amount of the oil liquid flowing through the proportioning valve 1, which is not preferable especially in the initial stage of braking. Bring results. That is, in the initial stage of braking, it is necessary to shorten the so-called dead time until the wheel cylinder is operated, the brake shoe contacts the wheel drum, and the braking action is substantially started. The liquid must be pumped by the wheel cylinder, but if a fixed throttle is provided in the operating system, a large amount of oil cannot be pumped in a short time.

Therefore, an object of the present invention is to provide a proportioning valve for vehicle braking that can prevent the generation of abnormal noise and can pump a sufficient amount of oil liquid to a wheel cylinder even during sudden braking.

d. Means for Solving the Problems In the proportioning valve for vehicle braking of the present invention, the housing and the plunger constitute a spool type throttle valve in the fluid passage between the input port and the output port, and the spool type throttle valve at the initial stage of the braking operation is formed. The throttle valve is opened at the non-operating position of the plunger, and is set at the operating position of the plunger during the actual braking period.

e. Action The vehicle braking proportioning valve of the present invention allows a sufficient amount of oil to pass during the initial braking operation, that is, before the brake shoe contacts the wheel drum (the plunger is in the non-operating state). The dead time is shortened, and during the actual braking period (when the plunger is operating), the passage of the oil liquid is reduced to prevent the generation of abnormal noise.

f. Embodiment FIGS. 1 to 3 show a proportioning valve for vehicle braking according to the present invention.

The valve housing of this proportioning valve 10 11
Has a large diameter cylinder portion 14, a medium diameter cylinder portion 15 and a small diameter cylinder portion 16 in this order between the input port 12 and the output port 13, and the input port 12 is opened to the large diameter cylinder portion 14. The output port 13 is open to the small diameter cylinder portion 16.
A plunger 17 is inserted into these cylinder parts 14, 15, 16 and a pressure regulating valve 18, which is an essential element of the proportioning valve 10, is formed between the plunger 17 and the valve housing 11. Further, a variable throttle valve 19 is configured.

The pressure adjusting valve 18 includes a medium diameter cylinder portion 15 and a small diameter cylinder portion 16.
An annular seal member 20 is provided on the boundary between the seal member 20 and the valve member portion 17a formed on the plunger 17, and a valve main portion is formed. Then, in this pressure regulating valve 18, the plunger 17 is
The valve body 17a is biased to the left in the figure, and the valve member 17a is sealed by the seal member 20.
Away from. Furthermore, with this pressure regulating valve 18,
The pressure acting area S ₁ of the plunger 17 that moves the plunger 17 to the right in FIG.
It is formed to be larger than the pressure acting area S _{2 of the} plunger 17 for moving 17 to the left.

The variable throttle valve 19 has a land 17b at the tip of the plunger 17 corresponding to the output port 13, and changes the opening area of the output port 13 according to the operation of the plunger 17 to change the flow rate of the oil liquid.

The operation of the vehicle braking proportioning valve described above will be described below.

FIG. 1 shows the proportioning valve 10 in a non-actuated state. In this state, the plunger 17 is located on the leftmost side by the biasing force of the spring 21.
In this state, the valve body portion 17a is separated from the seal member 20, and the medium diameter cylinder portion 15 and the small diameter cylinder portion 16 are communicated with each other. Further, in the throttle valve 19 in this state, the land portion 17b is at a position separated from the output port 13.

Now, when a master cylinder (not shown) is operated to feed the oil liquid into the valve 10 from the input port 12, the oil liquid passes through the gap between the seal member 20 and the valve body portion 17a, and then the valve body portion 1
It is fed from an output port 13 to a wheel cylinder (not shown) through a gap between the 7a and the small diameter cylinder portion 16 to bring the brake shoe into contact with the wheel drum. During that time (between the characteristic lines OA in FIG. 4), the throttle valve 19 is in the expanded state, and a sufficient amount of oil liquid is pumped to the wheel cylinders. During this period, the plunger 17 is in a non-operating state.

Further, when the oil liquid is pumped from the master cylinder, the differential pressure acting on the plunger 17 causes the plunger 17 to operate against the urging force of the spring 21, so that the valve body portion 17a is actuated as shown in FIG. It abuts on the seal member 20 and shuts off between the input port 12 and the output port 13. Furthermore, when the hydraulic fluid is pumped from the master cylinder, the differential pressure acting on the plunger 17 becomes small. Therefore, the plunger 17 is moved leftward by the urging force of the spring 21, the valve body 17a is separated from the seal member 20, and as a result, the oil liquid in the valve 10 is supplied to the wheel cylinder via the output port 13. Then, the differential pressure of the oil liquid acting on the plunger 17 increases again, the plunger 17 is actuated against the urging force of the spring 21, and the valve body portion 17a comes into contact with the seal member 20 and the input port 1
2 and the output port 13 are closed again. By repeating such an operation, the oil liquid is pumped to the wheel cylinder. During this time (between the characteristic lines AB in FIG. 4), the pressure at the output port 13 is reduced at a constant ratio with respect to the pressure at the input port 12. In addition, during this period, the land
17b is located at the opening of the output port 13 and narrows the passage for the oil liquid.

Here, release the pedal force of the master cylinder, and
When the pressure is reduced, the differential pressure acting on the plunger 17 increases, and as a result, the plunger 17 moves to the right as shown in FIG. This state is maintained until the wheel cylinder becomes inoperative. In this state, the land portion 17b is located away from the output port 13, and the output port 13 is communicated with the medium diameter cylinder portion 15 through the hole 17c penetrating the plunger 17. Therefore, the oil liquid of the wheel cylinder is returned to the medium diameter cylinder 15 via the output port 13 and the hole 17c, further to the input port 12 via the seal member 20, and then returned to the master cylinder. The pressure characteristic during this period is a characteristic line B-C-D in FIG. Of course, the throttle valve 19 during this period is in the expanded state.

FIG. 5 shows another embodiment of the proportioning valve for vehicle braking according to the present invention.

In this proportioning valve 10, the variable throttle valve 19 '
Between the input port 12 and the plunger 17.
In this variable throttle valve 19 ', a spring retainer 22 is arranged in the large diameter cylinder portion 14, a passage 23 is provided through the retainer 22, and a land portion 17b' is formed in the plunger 17.

And in this proportioning valve 10 ', the fifth
When the plunger 17 shown in the figure is in the non-operating state, the land portion 17b 'of the throttle valve 19' is at the position shown in FIG. 6 (a), and the throttle valve 19 'is expanded. Therefore, in the non-operating state of the plunger 17, that is, in the initial stage of the braking operation, a sufficient amount of oil liquid is fed from the input port 12 to the output port 13. Also, with this proportioning valve 10 ',
During the actual braking period when the braking action is actually performed,
The land portion 17b 'of the throttle valve 19' is at the position shown in FIG. 6 (b), and the throttle valve 19 'is throttled. Therefore, during the actual braking period, the amount of oil liquid fed from the input port 12 to the output port 13 is suppressed. Further, in this proportioning valve 10 ', upon releasing the braking, the land portion 17b' of the throttle valve 19 'is in the position shown in FIG. 6 (c), and the throttle valve is expanded. Therefore, in the braking release period, a sufficient amount of oil liquid is returned to the input port 12 from the output port 13.

FIG. 7 shows still another embodiment of the proportioning valve for vehicle braking according to the present invention.

In this proportioning valve 10 ″, the same throttle valve 19 as the throttle valve 19 of the first embodiment is connected to the output port 13 and the plunger.
A throttle valve 19 ″ is provided between the input port 12 and the plunger 17 and is substantially the same as the throttle valve 19 ′ of the second embodiment. However, in this throttle valve 19 ″, the land portion is provided. Since 17b ″ slides on the large-diameter cylinder portion 14, when the land portion 17b ″ is in the position shown in FIG. 7, that is, when the plunger 17 is in the non-operating state, the space between the input port 12 and the output port 13 is reduced. Since it will be stored in the land part,
A passage 24 is formed in 17b ″ to connect the large diameter cylinder portions 14 separated by the land portion 17b ″. In the throttle valve 19 ″, the land portion 17b ″ is shown in FIG. 8 (A) during the initial braking operation, the actual braking period, and the braking release period.
(A), FIG. 8 (B), (b), FIG. 8 (C), (c)
The throttle valve 19 ″ is in the open position, the throttle position, and the open position.
The operation of 9 "is substantially the same as that of the throttle valve 19 'shown in the second embodiment. The operation of the throttle valve 19 of the embodiment shown in FIG. 7 (third embodiment) is the same as that of the first embodiment. It goes without saying that the operation of the throttle valve 19 is the same.

In addition, in the above embodiment, the case where the proportioning valve for vehicle braking according to the present invention is interposed between the master cylinder and the wheel cylinder has been described, but the proportioning valve for vehicle braking according to the present invention includes the disc brake, That is, it goes without saying that it may be interposed between the master cylinder and the disc brake cylinder.

Further, in the above embodiment, the variable throttle valves 19, 19 ', 19 "are configured to be opened during the braking release period, but depending on the vehicle, the braking pressure may be released gently when the braking is released. In such a case, the hole 17c of the plunger 17 in the first embodiment is made smaller or eliminated, and the lands 17b ', 17b "in the second and third embodiments are extended leftward in each drawing. do it.

g. Effect of the Invention As described above, the proportioning valve for vehicle braking according to the present invention is provided with the variable throttle valve so that the actual braking period (plunger operating period), that is, the period during which abnormal noise is likely to occur. The oil liquid flow rate is suppressed, and therefore abnormal noise is prevented, and a large amount of oil is used during the initial braking operation (plunger non-operation period), that is, during the dead time until the brake shoe in the wheel cylinder contacts the wheel drum. It can supply liquid and has excellent operability. Moreover, the variable throttle valve is a spool type throttle valve that is configured between the valve housing and the plunger, so the structure is extremely simple.

[Brief description of drawings]

Each of FIGS. 1 to 3 is an overall sectional view showing each operating state of the vehicle braking proportioning valve according to the present invention, and FIG. 3B is an enlarged view of the throttle valve state in each state. 4 is a sectional view showing the characteristics of the proportioning valve, FIG. 5 is an overall sectional view showing another embodiment of the vehicle braking proportioning valve according to the present invention, and FIG. 7 (a), (b) and (c) are enlarged sectional views showing the operating state of the throttle valve in the proportioning valve, and FIG. 7 is a further embodiment of the vehicle braking proportioning valve according to the present invention. FIG. 8 (A), (a), (B), (b),
9C and 9C are enlarged sectional views and plan views showing the operating state of the throttle valve in the proportioning valve, and FIG.
FIG. 1 is an overall sectional view of a conventional vehicle braking proportioning valve, and FIG. 10 is an enlarged sectional view showing a pressure control valve of the proportioning valve. 10,10 ′, 10 ″ …… Proportioning valve for vehicle braking, 11 …… Housing, 12 …… Input port, 13 …… Output port, 14 …… Large diameter cylinder, 15 …… Medium diameter cylinder, 16 ...... Small diameter cylinder part, 17 ...... Plunger, 17a …… Valve body part, 17b, 17b ′, 17b ″ …… Land part, 17c …… Hole, 18 …… Pressure control valve, 19,19 ′, 19b ″… … Variable throttle valve, 20 …… Seal member, 21 …… Spring, 22 …… Retainer, 23 …… Passage, 24 …… Passage.

Claims (2)

[Scope of utility model registration request] 1. A spool-type throttle valve is constructed in a fluid passage between an input port and an output port by a housing and a plunger, and the throttle valve is opened at a non-operating position of the plunger at the initial stage of a braking operation. A vehicle braking characterized in that the throttle valve is throttled at the operating position of the plunger during the actual braking period, and the throttle valve is opened again at the operating position of the plunger during the braking release period. Proportioning valve for. 2. A spool-type throttle valve is formed in a fluid passage between an input port and an output port by a housing and a plunger, and the throttle valve is opened at a non-operating position of the plunger at the initial stage of a braking operation. A proportioning valve for vehicle braking, wherein the throttle valve is in a throttled state at an operating position of the plunger during an actual braking period and a braking release period.