JP2590386Y2 - Anti-skid brake device - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an anti-skid brake device used for the purpose of directional stability of a vehicle at the time of sudden braking of an automobile or the like and shortening of a braking distance.

[0002]

2. Description of the Related Art In general, an anti-skid brake device of this type repeats operations such as holding, reducing, holding and re-increasing fluid pressure in a wheel cylinder when a wheel goes to a skid during sudden braking or the like. Controls to maintain the optimum slip ratio.

[0003] Here, one example of a conventional anti-skid brake system by FIG. The figure shows a front-wheel brake circuit (right circuit in the figure) that controls left and right wheels independently and a rear-wheel brake circuit (left circuit in the figure) that controls left and right wheels simultaneously. As shown,
Since the basic circuit configuration is the same on the front wheel side and the rear wheel side,
Hereinafter, only the brake circuit on the rear wheel side will be described.
On the front wheel side, the same reference numerals are assigned to the same parts as the rear wheel side.

A is a main brake circuit for supplying brake fluid from the master cylinder 1 to the wheel cylinder 2 during normal braking, and B is a recirculation circuit for recirculating brake fluid in the wheel cylinder 2 during anti-skid control. The main brake circuit A and the recirculation circuit B are connected in parallel with each other, and electromagnetic valves 3 and 4 for opening and closing the circuits A and B are provided near the junction of the circuits A and B from the wheel cylinder 2.
Is interposed. A reservoir 5 and a pump 6 are interposed in the recirculation circuit B, and the brake fluid of the wheel cylinder 2 flows into the reservoir 5 when the pressure is reduced by the anti-skid control. It is returned to the master cylinder 1 side. Further, an orifice 7 is provided in the electromagnetic valve 3 on the side of the main brake circuit A, so that the orifice 7 ensures a gradual pressure increase characteristic during anti-skid control.

Since the anti-skid brake device has the above-described configuration, when anti-skid control is started by a control unit (not shown), a command signal is appropriately sent to the electromagnetic valves 3 and 4 so that the wheel cylinder 2
The operations of maintaining, reducing, maintaining, and increasing the pressure of the liquid pressure are repeated, and braking while maintaining an appropriate slip ratio is performed.

Incidentally, this similar structure is disclosed, for example, in
No. 16,657, JP-A-56-82650, and the like.

[0007]

An invention to be Solved] However, in the conventional antiskid brake apparatus described above, since adapted to obtain a slow increase pressure characteristic by the orifice 7 provided in the electromagnetic valve 3, as in the state of FIG. 5 The orifice 7 acts even during normal braking, and there is a problem that it is difficult to set the orifice 7 so as not to reduce the response during normal braking.

Accordingly, the present invention provides an anti-skid brake device which can easily realize both a desired gentle pressure increase characteristic during anti-skid control and an excellent response during normal braking. What you want to do.

[0009]

The present invention solves the above-mentioned problems.
The solution is usually to use the master
Supply brake fluid from cylinder to wheel cylinder
The main brake circuit and the wheel
A recirculation circuit for recirculating the brake fluid of the Linda;
The main brake circuit and the recirculation circuit depend on the skid condition of the wheels.
An anti-skid brake device that controls the flow of roads
The path between the junction of the two circuits and the master cylinder
In addition, a valve device that constitutes a throttle during anti-skid control is interposed.
The valve device is provided with a master system.
Detects the difference between the hydraulic pressure of the cylinder and the hydraulic pressure at the junction of the two circuits
When the differential pressure falls below the set pressure, the main brake
Throttling means for turning the path inside, and
The difference between the hydraulic pressure and the hydraulic pressure of the wheel cylinder is detected, and the
When the difference between the two is less than the set pressure, the throttle means is maintained in the released state.
And a squeeze release means to be provided.

[0010]

When the pressure in the anti-skid control is reduced or held thereafter, the difference between the hydraulic pressure of the master cylinder and the hydraulic pressure of the wheel cylinder becomes larger than the set pressure as a result of the hydraulic pressure of the wheel cylinder escaping to the recirculation circuit when the pressure is reduced. Therefore, the aperture release means does not operate. For this reason, if the difference between the hydraulic pressure of the master cylinder and the hydraulic pressure at the junction of the two circuits becomes equal to or less than the set pressure in the anti-skid control pressure reduction or holding state,
When the means brings the main brake circuit into a throttled state, and then the pressure in the master cylinder slightly increases with respect to the liquid pressure at the junction of the two circuits due to the re-pressure increase of the anti-skid control, the throttling action of the throttle means works and the pressure gradually increases. Pressure characteristics can be obtained. Further, at the start of the braking operation of the normal brake, since the difference between the hydraulic pressure of the master cylinder and the hydraulic pressure of the wheel cylinder is equal to or less than the set value, the throttle release unit operates, and the throttle operation of the throttle unit does not work. Then, until the hydraulic pressure of the wheel cylinder becomes equal to the hydraulic pressure of the master cylinder, the hydraulic pressure of the master cylinder and the hydraulic pressure at the junction of the two circuits
Does not fall below the set pressure , the throttle action by the throttle means does not work.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of the present invention will be described with reference to FIGS.
Will be described. FIG. 4 shows a front-wheel brake circuit (see FIG. 4).
The circuit on the middle right side and the brake circuit on the rear wheel side (the circuit on the left side in the figure)
Road) are shown at the same time, but both brake circuits differ only in whether they control the left and right wheels independently or simultaneously, and other basic configurations are the same.
It describes only the brake circuit for the rear wheels, the brake circuit before wheel side and by the same reference numerals to the rear wheel side and the same parts.

In FIG. 4, A is a main brake circuit that supplies brake fluid from the master cylinder 1 to the wheel cylinder 2 during normal braking , and B is a recirculation circuit that recirculates brake fluid in the wheel cylinder 2 during anti-skid control. Road . The return circuit B is connected in parallel to the main brake circuit A, and electromagnetic valves 3 and 4 for opening and closing the circuits A and B are provided near the junction of the main brake circuit A and the return circuit B on the wheel cylinder 2 side. There has been interposed. The recirculation circuit B has a reservoir 5 into which the brake fluid of the wheel cylinder 2 flows when the pressure is reduced by the anti-skid control.
And a pump 6 for sending out the brake fluid in the direction of the master cylinder 1 to prepare for the re-pressure increase.
Incidentally, in the figure M is a motor for rotating the pump 6.

A passage a from the master cylinder 1 to the junction of the main brake circuit A and the recirculation circuit B (on the side of the master cylinder 1) has a valve device 53 which is a main part of the present invention.
Is interposed.

The valve device 53 includes a master cylinder side port 35, a circuit side port 36, and a pilot port 58 for introducing the hydraulic pressure of the wheel cylinder 2, as shown in FIGS. A first plunger 38 and a second plunger 39 are slidably accommodated therein. D in FIG. 4 is the wheel cylinder 2
And a pilot passage connecting the pilot port 58. The first plunger 38 is provided between the ports 35 and 58, and the inside of the casing 34 is provided with a first hydraulic chamber 40 into which the hydraulic pressure of the master cylinder 1 is introduced and a hydraulic pressure of the wheel cylinder 2. The third hydraulic chamber 54 is defined. In contrast, the second plunger 39 has ports 35 and 36
The first hydraulic chamber 40 and the second hydraulic chamber 42 define the interior of the casing 34 between the first hydraulic chamber 40 and the second hydraulic chamber 42. A spring 43 is provided in the third hydraulic chamber 54, and a spring 44 is provided in the second hydraulic chamber 42. The spring 43 on the third hydraulic chamber 54 side is a spring 44 on the second hydraulic chamber 42 side.
The first plunger 38 moves the second plunger 39 in a state in which the spring reaction force is set to be larger than that of the first plunger 38 and the pressure difference between the first hydraulic chamber 40 and the third hydraulic chamber 54 does not reach the set value. It is designed to press rightward. Reference numeral 45 denotes a stopper for restricting the displacement of the second plunger 39 in the right direction in the figure, and reference numeral 46 denotes an inner periphery of the canning 34 such that the circuit-side port 36 faces a side surface of the second plunger 39 with a predetermined width. It is an annular groove formed on the surface.

A tapered notch 47 is formed on the outer peripheral surface of the second plunger 39 on the first hydraulic pressure chamber 40 side. The notch 47 is formed so that the first hydraulic chamber 40 communicates with the annular groove 46 only when the second plunger 39 is located on the right side in the drawing. Second plunger 39
A passage 4 for communicating the annular groove 46 with the second hydraulic chamber 42
8, a passage 49 for communicating the annular groove 46 with the first hydraulic pressure chamber 40 is formed, and an orifice 50 that acts as a throttle when the liquid passes through is formed in the passage 48.
The passage 49 is provided with a check valve 51 that allows only the flow of the brake fluid from the annular groove 46 toward the first hydraulic chamber 40 (in the return direction).

Further, a cut-out passage 52 is formed in the end face of the first plunger 38 which abuts on the second plunger 39. Even when the first plunger 38 and the second plunger 39 are in contact with each other, the passage 49 and the first plunger 39 are in contact with each other. The hydraulic chamber 40 communicates with the notch passage 52.
In the case of this embodiment, the second plunger 39 having the orifice 50, the spring 44, the first hydraulic chamber 40, and the second hydraulic chamber 42 constitute the throttle means in the present invention, and
The plunger 38, the spring 43, the first hydraulic chamber 40, and the third hydraulic chamber 54 constitute a throttle release unit.

With such a configuration, the anti-skid brake device of this embodiment operates as follows.

(1) At the time of normal braking When the brake pedal 8 is not depressed,
As shown in FIG. 1, the first plunger 38 and the second plunger 39 are located rightward in the figure, and the first hydraulic chamber 40 and the annular groove 46 communicate with each other by a notch 47.

When the brake pedal 8 is depressed from this state, the difference between the hydraulic pressure at the junction of the master cylinder 1 and the two circuits A and B, the master cylinder 1 and the wheel cylinder 2
Since the difference between the hydraulic pressures of the first plunger 38 and the
Moves to the left against the resilience of the spring 43 and the hydraulic pressure of the wheel cylinder 2 as shown in FIG. 2 , and the brake fluid flowing into the first hydraulic chamber 40 from the master cylinder side port 35 is cut off. The gas passes through the notch 47 into the annular groove 46, and is further supplied from the circuit side port 36 to the wheel cylinder 2 through the main brake circuit A. Then, in the latter period of the braking, the difference between the hydraulic pressure of the master cylinder 1 and the hydraulic pressure of the wheel cylinder 2 disappears, so that the first plunger 38 is returned rightward again as shown in FIG.

When the brake pedal 8 is returned from this state, the brake fluid on the wheel cylinder 2 side passes from the annular groove 46 through the passage 49 and the notch 47 to the first hydraulic chamber 40.
To return to the master cylinder 1 from the first hydraulic chamber 40.

(2) At the time of anti-skid control At the time of pressure reduction of the anti-skid control, the wheel cylinder 2
Flows to the recirculation circuit B side, and the difference between the hydraulic pressure of the master cylinder 1 and the hydraulic pressure of the wheel cylinder 2 becomes large enough to overcome the resilience of the spring 43. The plunger 38 moves to the left as shown in FIG. 3 , and at this time, the electromagnetic valve 3 closes the main brake circuit A and the hydraulic pressure at the junction between the master cylinder 1 and the two circuits A and B is balanced. Therefore, the second plunger 39 moves leftward due to the force of the spring 44.
For this reason, the communication between the first hydraulic chamber 40 and the annular groove 46 by the notch 47 is cut off, and the valve device 53 is brought into a state in which the orifice 50 acts as a throttle.

When the pressure increase of the anti-skid control is started from this state, the electromagnetic valve 3 opens the main brake circuit A, and the brake fluid of the main brake circuit A flows into the wheel cylinder 2. A slight pressure difference occurs between the master cylinder side port 35 and the circuit side port 36. Then, the second plunger 39 moves rightward in the drawing as the depression amount of the brake pedal 8 increases, and as a result, the brake fluid in the second hydraulic pressure chamber 42 flows through the passage 48.
And flows into the annular groove 46 through the orifice 50. Then, the brake fluid flowing into the annular groove 46 is supplied to the main brake circuit A via the circuit-side port 36. As described above, when the pressure is increased again in the anti-skid control, the brake fluid passes through the orifice 50, so that the orifice 50 can obtain a throttling action.

As described above, in the case of this anti-skid brake device as well, the throttling effect of the orifice 50 can be obtained only during the anti-skid control. Excellent responsiveness at the time can be secured. In particular, in the case of this anti-skid brake device, the first plunger 38
When the brake pedal moves leftward in the figure, the brake fluid corresponding to the reduction in the volume of the third hydraulic chamber 54 is supplied to the wheel cylinder 2 through the pilot port 58 and the pilot passage D. There is also an advantage that the responsiveness of the wheel cylinder 2 is good.

[0024]

Effects of the invention] above, the present devised is, in the valve device, trout
Detects the difference between the hydraulic pressure of the tar cylinder and the hydraulic pressure at the junction of the two circuits
When the differential pressure falls below the set pressure, the main brake
Throttling means for turning the path inside, and
The difference between the hydraulic pressure and the hydraulic pressure of the wheel cylinder is detected, and the
The throttle means is maintained in the released state when the difference between
Since the throttle release means is provided, the throttle function of the throttle means can be obtained only when the pressure is reduced in the anti-skid control or the state is changed from the state of holding to the state of the pressure increase again. Therefore, according to the present invention, it is possible to ensure both a reliable slow pressure increase characteristic during anti-skid control and an excellent response during normal braking.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

FIG. 2 is a sectional view showing the embodiment.

FIG. 3 is a sectional view showing the embodiment.

FIG. 4 is a circuit diagram showing the embodiment.

FIG. 5 is a circuit diagram showing a conventional technique.

[Explanation of symbols]

1: Master cylinder, 2: Wheel cylinder, 53:
Valve device, A: main brake circuit, B: recirculation circuit, a: passage, 38: first plunger (throttle releasing means), 39: second plunger (throttle means), 40: first hydraulic chamber (throttle means, Throttling release means), 42... Second hydraulic chamber (throttling means),
43: Spring (throttle release means), 44: Spring (throttle means), 54: Third hydraulic chamber (throttle release means).

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁶ , DB name) B60T 15/36 B60T 8/48

Claims (1)

(57) [Scope of request for utility model registration] 1. A main brake circuit for supplying brake fluid from a master cylinder to a wheel cylinder during normal braking, and a recirculation circuit for recirculating brake fluid in the wheel cylinder during anti-skid control. a antiskid brake system for controlling the flow of the main brake circuit and a reflux circuit, the two
In the passage between the junction of the road and the master cylinder,
A valve device that composes the throttle during Kid control is interposed
In things, the valve device, the master cylinder fluid pressure and said second circuit
The difference in hydraulic pressure at the junction is detected, and the differential pressure falls below the set pressure.
A throttle means for the state squeezed in the main brake circuit when Tsu, detects the difference between the fluid pressure and the wheel cylinder hydraulic pressure of the master cylinder, the throttle means when the difference between the fluid pressure is below the set pressure An anti-skid brake device provided with an aperture release means for maintaining the release state.