JPS6039317Y2 - Deceleration sensing type brake fluid pressure control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a deceleration sensing type brake hydraulic pressure control device installed in a rear hydraulic circuit connecting a master cylinder and a rear wheel cylinder in a vehicle.

In a deceleration-sensing brake fluid pressure control system, an inertial valve element that senses deceleration and seats on the valve seat to shut off the rear hydraulic circuit is located in the brake fluid in the rear hydraulic circuit. , it is easily affected by the flow of brake fluid, and operating performance may become unstable.

The present invention has been devised to deal with such problems, and one embodiment thereof will be described below based on the drawings.

The figure shows a deceleration sensing type brake fluid pressure control device 100 according to the present invention.
It shows the brake system including master cylinder 1.
The front oil chamber 11 of No. 0 is directly connected to the front wheel cylinder 12.12 by a conduit P□, and the rear oil chamber 13 is connected to the rear wheel cylinder 14.14 by a rear system conduit through which a brake fluid pressure control device 100 is interposed. has been done.

The brake fluid pressure control device 100 includes a first control valve 110, which is known as a deceleration sensing type control valve, and a second control valve 120. incorporates a valve seat 114 and a ball valve body 115 that senses deceleration and seats on the valve seat 114 to shut off the passage 113.

The second control valve 120 has a first port 120a connected to the rear oil chamber 13 of the master cylinder 10 through a conduit P2, and a second port 120b connected to the inlet 111 of the first control valve 110 through a conduit P3. , a third port 12 connected to an outlet 112 of the first control valve 110 by a conduit P.
0c and rear wheel cylinder 14.1 by conduit P5.
4 and a fourth port 120d connected to the first port 120d.
The port 120a and the second port 120b are connected by a passage 120e, and the third port 120C and the fourth port 1
20d are connected by a passage 120f.

Therefore, in this second control valve 120, the passage 12
Spool valve body 12 with orifice 121a in 0e
1 is incorporated, and the passages 120e and 12of are connected by a bypass passage 120g, and this bypass passage 120
A cut valve ■ is incorporated in g.

That is, in this embodiment, the conduit P29 passage 12
0 e, conduit P3f passage 113, conduit 144 passage 120
An orifice 121a is provided in series with the ball valve body 115 in the rear hydraulic circuit consisting of the valve seat 114 and the ball valve body 115, and a bypass is provided for the series circuit consisting of the orifice 121a, the valve seat 114, and the ball valve body 115. 120 g of passages are provided in parallel.

The spool valve body 121 is vertically movable and is urged upward by a spring 122.

In this spool valve body 121, the orifice 121
When the differential pressure before and after a is less than a predetermined value, the spool valve body 12
1 is in the illustrated position, and the seal member 121b fixed to the spool valve body 121 is in close contact with the inner wall as shown in the figure.
When all the brake fluid flowing from the first port 120a to the second port 120b passes through the orifice 121a, and the differential pressure across the orifice 121a exceeds a predetermined value, the spool valve body 121 moves downward to seal. Member 12
1b is no longer tightly attached, and the brake fluid flows from the first port 120a to the second port 120b through the orifice 121.
a and a groove 121c provided on the outer periphery of the spool valve body 121.

The cut valve ■ consists of a valve seat member 123 fixed fluid-tightly in the bypass passage 120g, and a poppet valve body 125 urged leftward by a spring 124. The left end of the poppet valve body 125 is connected to the piston 126. It is touching the right edge.

The piston 126 is movable to the left according to the hydraulic pressure in the passage 120f, and in the illustrated state, the piston 126
27 to the right, the poppet valve body 125 is separated from the valve seat member 123 and is brought into contact with the left end of the valve seat member 123.

Therefore, in the cut valve V, when the hydraulic pressure in the passage 120f is equal to or higher than the set value (this value is a relatively low value before the ball valve body 115 is seated on the valve seat 114),
The piston 126 moves to the left and comes off the poppet valve body 125, and the poppet valve body 125 seats on the valve seat member 123, closing the bypass passage 120g.

In this embodiment configured as described above, when the brake pedal 15 is depressed, the brake fluid in the front oil chamber 11 of the master cylinder 10 is transferred to the front wheel cylinder 12.
．． At the same time, the brake fluid in the rear oil chamber 13 flows toward the rear wheel cylinder 14, 14 via the brake fluid pressure control device 100, and the brake fluid in each oil chamber 11, 1
The hydraulic pressure in each wheel cylinder 12, 12, 14, 1
4 respectively, and the vehicle is braked.

By the way, during this braking, in the rear hydraulic pressure circuit, if the hydraulic pressure in the passage 120f of the second control valve 120 is less than the set value (corresponding to the initial stage of depression of the brake pedal 15), the cut valve ■ is activated. is open.

Therefore, the brake fluid flowing from the rear oil chamber 13 of the master cylinder 10 toward the rear wheel cylinder 14 is directed to the orifice 121a in the second control valve 120.
The flow is suppressed by this, and a large amount of brake fluid flows toward the rear wheel cylinder 14.14 through the bypass passage 120g.

Therefore, almost no flow of brake fluid occurs in the passage 113 within the first control valve 110, and the ball valve body 115 is not affected by the flow of brake fluid.

This action occurs when the hydraulic pressure in the passage 120f of the second control valve 120 exceeds the set value, causing the cut valve 1 to close the bypass passage 1.
Obtained before closing 20g.

When the hydraulic pressure increases thereafter, pipe P2. Passage 120e with orifice 121a, conduit P3. First control valve 110. Conduit P4? The hydraulic pressure in the rear oil chamber 13 is transferred to the rear wheel cylinder 14 via the passage 120f and the pipe P5.
．． 14, and by the known actuation of the first control valve 110 (rolling of the ball valve body 115 onto the valve seat 114 and movement of the differential pistons 116, 117), the rear wheel cylinder 1
4. The hydraulic pressure applied to 14 is controlled to be reduced.

In addition, in this rear hydraulic pressure circuit, as described above, since the hydraulic pressure increases by more than the set value via the orifice 121a, the curvature of the orifice 121a causes the hydraulic pressure in the rear oil chamber 13 to increase. Transmission to control valve 110 is delayed-controlled.

This delaying effect is noticeable when the brake pedal 15 is depressed rapidly.

Therefore, when the brake pedal 15 is depressed rapidly, the transfer timing of the ball valve body 115 is delayed and the first control valve 11
The problem that the pressure reduction control at 0 is delayed (the so-called problem due to an increase in the corner point liquid pressure) is effectively eliminated.

In addition, in this embodiment, the orifice 121a is provided in the spool valve body 121, and when the brake pedal 15 is depressed when the brake fluid has high viscosity (under low temperature) or when the brake pedal 15 is depressed under normal temperature conditions. When the brake pedal 15 is depressed extremely rapidly, the orifice 121
When the differential pressure before and after a exceeds a predetermined value, the spool valve body 1
21 moves downward and the brake fluid passes through the orifice 121a and 1121c of the spool valve body 121, so the excessive action of the orifice 121a is nullified and the delay in brake effectiveness is compensated.

Note that when implementing the present invention, the orifice corresponding to the orifice 121a of the above embodiment is replaced with the first control valve 110.
or the passage 120f of the second control valve 120
Even if it is provided in the first control valve 110 side part, the same operation and effect as in the above embodiment can be expected.

Furthermore, the present invention is not limited to the above-mentioned embodiments, but can of course be implemented in the same manner as the above-described embodiments by attaching the second control valve 120 to various known deceleration sensing control valves.
It is also possible to implement the deceleration sensing type control valve (first control valve 110) and second control valve 120 by integrally configuring them.

[Brief explanation of drawings]

The figure is a brake system diagram including a deceleration sensing type brake fluid pressure control device according to the present invention. Explanation of symbols, 10...Master cylinder, 14
・・・・・・Rear wheel cylinder, 100・・・・・・
・Deceleration sensing type brake fluid pressure control device, 114...
Valve seat, 115...Ball valve body (inertia valve body), 1
20g... Bypass passage, 121a...
・Orifice,■・・・・・・Cut valve.

Claims (1)

[Scope of utility model registration request] An orifice is provided in series with an inertial valve body that senses deceleration in a rear hydraulic pressure circuit connecting the master cylinder and the wheel cylinder and seats on a valve seat to shut off the rear hydraulic pressure circuit; A bypass passage is provided in parallel to the series circuit consisting of the orifice, the valve seat, and the inertial valve element, and the hydraulic pressure in the rear hydraulic pressure circuit is applied to the bypass passage when the inertial valve element is seated on the valve seat. A deceleration sensing type brake hydraulic pressure control device comprising a cut valve that closes the bypass passage when the pressure exceeds a relatively low set value.