JPH0485159A - Antiskid brake controller - Google Patents

Abstract

PURPOSE:To absorb any kickback as well as to promote the miniaturization of a modulator by installing a diaphragm partitioning a cylinder into a first oil chamber and a second oil chamber, while connecting these first and second oil chambers to the respective pump discharge sides of first and second brake systems. CONSTITUTION:When an antiskid brake controlling pump 16 discharges at the side of a first brake system A, by way of example, the side of a second brake system B is in a suction state. In this state intact, a side of pressure in a first oil chamber 25 becomes larger than that in a second oil chamber 26, so that a diaphragm 24 is elastically deformed to the right, and thereby volume in the first oil chamber 25 grows larger. In brief, since volume in the oil chamber at the discharge side of the pump 16, where a kickback is liable to be produced, becomes enlarged, the kickback is made so as to be absorbed yet more effectively. Consequently, the diaphragm 24 is used in common with two systems and thereby the kickback is reducible, thus miniaturization of a modulator is yet more surely promotable.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an anti-skid brake control device installed in a two-system brake control device in a vehicle. The present invention relates to an anti-skid brake control device in which discharged brake fluid is returned to a brake fluid supply passage between a master cylinder and a wheel cylinder using a pump.

(Prior art) In general, anti-skinned brake control is a system in which, when it is detected that a wheel is in a skid state during braking, the braking force on that wheel is weakened to eliminate the skid state, and then the braking force is increased again. This stabilizes the vehicle's handling and performs brake control so that the braking distance is as short as possible.

(Problems to be Solved by the Invention) As an example of an anti-skid brake control device that performs such brake control, the one shown in FIG. 2 can be considered.

As shown in FIG. 2, the brake circuit to which this anti-skinned brake control device is connected is formed into two systems, including a first brake system A and a second brake system B. In the first brake system A, the brake fluid pressure in one oil chamber 1a of the master cylinder 1 with a hydraulic pressure booster is supplied to the front wheel cylinder 2 of the right front wheel FR, and the brake fluid pressure is supplied to the front wheel cylinder 2 of the right front wheel FR via the provocation valve PvL. It is supplied to the rear wheel cylinder 3 of the rear wheel RL. Similarly, in the second brake system B, the brake fluid pressure in the other oil chamber 1b of the tandem master cylinder 1 is supplied to the wheel cylinder of the left front wheel FL, and the brake fluid pressure is supplied to the right rear wheel cylinder via the provisioning valve P V ++. It is designed to be supplied to the wheel cylinder of wheel RR. That is, these first and second brake systems A and B are formed in a diagonal piping system. 1st and 2nd brake system A
, B have the same configuration, henceforth, the first brake system A will be explained, and the explanation of the second brake system B will be omitted.

In the first brake system A, a first supply passage 4 communicates with the oil chamber 1a, and this first supply passage 4 branches into a second supply passage 5 and a third supply passage 6 midway. Second supply passage 5
is in communication with the front wheel cylinder 2, and the third supply passage 6 is in communication with the rear wheel cylinder 3. These second and third supply passages 5.6 are provided with first and second flow rate regulating valves 7.8, each of which is a mechanical valve that selectively communicates or shuts off the supply passages 5, 6.
are provided, and each wheel cylinder 2, 3 is connected to the oil chamber 1a of the master cylinder 1, or each wheel cylinder 2, 3 is provided downstream of these first and second flow rate regulating valves 7, 8. and a low pressure accumulator (sump) 11 that maintains a pressure of, for example, about 2 to 3 atmospheres through an orifice 9.10. 12.13 are provided.

The low pressure accumulator 11 is connected via a check valve 14 to a pump 16 driven by a motor 15, and the pump 16 is connected via a check valve 17 to a volume chamber 18 that absorbs the pulsation of the pump 16. There is. Volume room 18
are connected to the first supply passage 4 via a check valve 19 and a brake fluid reflux suppression orifice 20, and are connected to the pilot boats 7a, 8a of the first and second flow rate regulating valves 7.8.
is connected to. Furthermore, the passage between the check valve 19 and the brake fluid reflux suppression orifice 20 is an orifice 2, respectively.
1.22 to the first and second flow rate regulating valves 7, 8 and the first
and the second flow path switching control valves 12 and 13, and communicate with the second and third supply passages 5 and 6.

In the anti-skid brake control device configured in this way, normally each valve 7, 8, 12, 13 is in the state shown, and the oil chamber 1a is in communication with the front and rear wheel cylinders 2.3. . Therefore, the brake fluid pressure generated in the oil chamber 1a of the master cylinder 1 during braking is:
First, second and supply passages4. 5. 6 to the front and rear wheel cylinders 2.3, and the brakes of the right front wheel FR and the right rear wheel RL are operated, respectively.

When it is detected that the front right wheel FR is in a skid state, the solenoid of the first passage switching valve 12 is energized by the detection signal, so the position of the first passage switching valve 12 is changed and the oil is turned off. The second supply passage 5 communicating between the chamber 1a and the front wheel cylinder 2 is shut off, and the flow path of the brake fluid is switched so that the front wheel cylinder 2 is communicated with the low pressure accumulator 11. Therefore, the brake fluid in the front wheel cylinder 2 flows out to the low pressure accumulator 11, so the brake fluid pressure in the front wheel cylinder 2 decreases.

The brake fluid that has flowed into the low-pressure accumulator 11 is forced back into the oil chamber 1a of the master cylinder 1 by the piston pump 16 via the check valves 17, 19 and the brake fluid return suppression orifice 20.

As a result, the pressure in the oil chamber 1a increases, the brake pedal is pushed back a little, and the driver senses that anti-skid control is being performed. In that case, the pulsation of the pump 16 is absorbed by the volume chamber 18, and the pulsation is suppressed by the brake fluid reflux suppression orifice 20, so that it is hardly transmitted to the oil chamber 1a, so that the pulsation of the pump 16 affects the brake pedal. In other words, there are almost no kick packs.

Further, the brake fluid recirculated by the pump 16 is
And it acts on each boat 7a, 8a of the second flow rate regulating valves 7, 8 as a pilot pressure. front wheel cylinder 2
Since the brake fluid pressure in the rear wheel cylinder 3 has decreased, this pilot pressure causes the first flow regulating valve 7 to shut off the second supply passage 5. However, since the brake fluid pressure in the rear wheel cylinder 3 has not decreased, this pilot pressure The second flow rate regulating valve 8 does not block the third supply passage 6 due to the pressure.

When the skid of front wheel cylinder 2 is resolved,
The first flow path switching valve 12 is switched to the original position, that is, the position where the front wheel cylinder 2 and the oil chamber 1a communicate with each other. Therefore, the brake fluid returned by the pump 16 is supplied to the front wheel cylinder 2 while its flow rate is restricted by the orifice 21. Therefore, the brake fluid pressure in the front wheel cylinder 2 rises again, and the braking force gradually increases.

When the right rear wheel 3 and the left front wheel FL and right rear wheel RR of the second system B are in a skid state, antiskid control is performed in the same manner as described above.

By the way, the volume chamber 18 for reducing kick pack during anti-skid brake control merely has a volume and is not structured to actively absorb pulsation. For this reason, the volume chamber 18 needs to have a certain amount of volume, and the volume is generally set to about 20 cc per system. Therefore, there is a problem that the modulator becomes large.

The present invention has been made in view of these problems, and its purpose is to reliably reduce kick pack during anti-skid brake control while also making it possible to downsize the modulator. An object of the present invention is to provide an anti-skid brake control device.

(Means for solving the problem) In order to solve the above-mentioned problem, the invention of claim 1 provides the first
a first brake system having a first brake supply passage communicating the master cylinder and the first wheel cylinder;
a second brake system having a second brake supply passage communicating between the master cylinder and the second wheel cylinder; and a brake fluid supply passage provided in each of the first and second brake systems; A second master cylinder communicates with the first and second wheel cylinders, respectively, and disconnects the first and second wheel cylinders from the master cylinder when the wheels are in a skid state, and communicates with the first and second low pressure accumulators. The first thing that goes through
and a second anti-skid brake control valve, and a pump that returns the brake fluid of the first and second low pressure accumulators to the first and second brake fluid supply passages, the anti-skid brake control device comprising: a cylinder and a diaphragm defining a first oil chamber and a second oil chamber in the cylinder, and the first oil chamber is connected to the pump discharge side of the first brake system. , the second oil chamber is connected to the pump discharge side of the second brake system.

Further, the invention of claim 2 provides that the pump is connected to the first and second pumps.
It is characterized in that it is constituted by a piston pump in which when the pump on one brake system side of the system brake system is in a discharge state, the pump on the other brake system side is in a suction state.

(Function) In the anti-skid brake control device according to the present invention having such a configuration, the diaphragm is elastically deformed in the direction of lower pressure and the volumes of the first and second oil chambers of the cylinder are changed, thereby suppressing pump pulsation. etc. pressure fluctuations will be actively absorbed. Therefore, the first and second
Even if the volume of the oil chamber is not as large as a conventional volume chamber, kickback can be effectively reduced. Since the cylinder can be made smaller, the modulator can also be made smaller.

Further, since the cylinder is simply provided with a diaphragm, the structure is simple and the number of parts is small.

In particular, in the invention of claim 2, the pressure in the oil chamber of the cylinder on the brake system side when the pump is in the discharge state is
Since the pressure in the oil chamber is greater than the pressure in the oil chamber on the brake system side where the pump is in the suction state, the diaphragm is elastically deformed toward the brake system side where the pump is in the suction state. Therefore, the volume of the oil chamber on the brake system side where the pump is in the discharge state increases, so that kickback can be absorbed even more effectively. Therefore, by sharing the diaphragm between two systems in this way, kickback can be reduced, so the number of parts can be reduced, and the modulator can be made smaller even more reliably.

(Example) Hereinafter, the present invention will be explained in detail using the drawings.

FIG. 1 is a control circuit diagram corresponding to part 0 of FIG. 2, partially showing an embodiment of an anti-skin brake control device according to the present invention. Note that the same components as those of the anti-skid brake control device described above are given the same reference numerals, and their explanations will be omitted.

In the above example, the first and second brake systems A.

In contrast to the case where the volume chambers 18 having a simple volume are arranged independently in each case, in this embodiment, as shown in FIG. 1, one cylinder 23 is provided, and the inside of this cylinder The first oil chamber 2 is opened by a flexible diaphragm 24.
5 and a second oil chamber 26. Normally, the diaphragm 24 does not elastically deform to either side of the first oil chamber 25 or the second oil chamber 26, and therefore the first oil chamber 25 and the second oil chamber 26 are maintained at approximately the same volume. .

Further, the first oil chamber 25 and the second oil chamber 26 communicate with a passage between the pair of check valves 17 and 19 of the first and second systems A and B, respectively. This diaphragm 24 has an effective diameter of about 10 mm, and a diaphragm of about 21 mm.
If it is elastically deformed to a certain extent, it is possible to sufficiently reduce kickback during anti-skinned brake control.

In the anti-skid brake control device of this embodiment configured in this way, the diaphragm 24 is elastically deformed toward the lower pressure oil chamber as shown by the chain double-dashed line due to pressure fluctuations such as pump pulsation, and the cylinder 23 is Each oil chamber 25, 26
Since the volume of the gas changes, pressure fluctuations are actively absorbed.

Therefore, kickback can be effectively reduced without increasing the volumes of the oil chambers 25 and 26 unlike the conventional volume chamber 18. Furthermore, since the cylinder 23 can be made smaller, the modulator can also be made smaller. Furthermore, since the diaphragm 24 is simply provided on the cylinder 23, the number of parts is small and the structure is extremely simple.

Moreover, when the anti-skid brake control pump 16 is discharging, for example, on the first brake system A side, it is in a suction state on the second brake system B side. In this state, the pressure in the first oil chamber 25 is greater than that in the second oil chamber 26, so the diaphragm 24 is elastically deformed to the right, and the volume of the first oil chamber 25 increases.

That is, since the volume of the oil chamber on the discharge side of the pump 16, where kickback is likely to occur, is increased, kickpack can be absorbed even more effectively. Therefore, by sharing the diaphragm 24 between two systems in this way, kick pack can be reduced, and the modulator can be further downsized.

Furthermore, since the structure is such that pressure fluctuations are actively absorbed as described above, the brake fluid recirculation suppression orifice 20
Even if this is omitted, the kick pack can be sufficiently reduced.

(Effects of the Invention) As is clear from the above description, in the anti-skid brake control device according to the present invention, the diaphragm is elastically deformed due to pressure fluctuations such as pump pulsation, and the volumes of the first and second oil chambers of the cylinder are reduced. Since the pressure changes, pressure fluctuations can be actively absorbed. Therefore, kick pack can be effectively reduced without increasing the volumes of the first and second oil chambers like the volume chambers of the conventional anti-skid brake control device shown in FIG.

Furthermore, since the cylinder can be made smaller, the modulator can also be made smaller.

Furthermore, since the cylinder is simply provided with a diaphragm, the number of parts is small and the structure is extremely simple.

In particular, in the invention of claim 2, the diaphragm is shared by the two systems, and the volume of the oil chamber on the brake system side where the pump is in the discharge state is increased, so that kick pack can be absorbed even more effectively. become. Therefore, the modulator can be made smaller even more reliably.

[Brief explanation of the drawing]

FIG. 1 is a control circuit diagram schematically showing a part of an embodiment of an anti-skid brake control device according to the present invention, and FIG. 2 is a control circuit of an anti-skid brake control device considered as an example. 1... Tandem master cylinder, 2... Front wheel cylinder, 3... Rear wheel cylinder, 4
...first supply passage, 5...second supply passage, 6...
3rd supply passage, 7... first flow path switching valve, 8... second
Flow path switching valve, 11...Low pressure accumulator (sump device), 12...First flow rate adjustment valve, 13...Second flow rate adjustment valve, 16...Pump, 20...Brake fluid reflux suppression Orifice, 23...Cylinder, 24...Diaphragm, 25...1st oil chamber, 26...2nd oil chamber 1) L-ff Senkita A v, 2 Brake A Shituki tB Patent applicant: Jidosha Kiki Co., Ltd. Patent attorney Kenji Aoki (7 others)

Claims (2)

[Claims] (1) A first brake system having a first brake supply passage that communicates between the first master cylinder and the first wheel cylinder, and a second brake system that has the second brake supply passage that communicates the second master cylinder and the second wheel cylinder. 2 brake systems, and are arranged in the respective brake fluid supply passages of these first and second brake systems.
a first and second wheel cylinder that communicates with the master cylinder and the first and second wheel cylinders, isolates the first and second wheel cylinders from the master cylinder when the wheels are in a skid state, and communicates with the first and second low pressure accumulators; An anti-skid brake control device comprising: first and second anti-skid brake control valves; and a pump that returns brake fluid from the first and second low-pressure accumulators to the first and second brake fluid supply passages, respectively. , a cylinder is provided with a diaphragm defining a first oil chamber and a second oil chamber in the cylinder, and the first oil chamber is connected to the pump discharge side of the first brake system. and the second oil chamber is connected to the pump discharge side of the second brake system. (2) The pump is constituted by a piston pump in which when the pump on one of the first and second brake systems is in a discharge state, the pump on the other brake system is in a suction state. The anti-skid brake control device according to claim 1, characterized in that: