JP2942598B2 - Brake equipment - Google Patents

Description

The present invention relates to a brake device provided with a hydro booster and an anti-skid hydraulic pressure control device, and more specifically, a common pump for both a hydro booster and an anti-skid hydraulic pump. The present invention relates to an improvement in a brake device driven by a motor.

(Prior Art) A technique of driving these two types of pumps by a common prime mover has been conventionally known, for example, as disclosed in JP-A-63-166648. The advantage of this technique is that the unit occupied by the pumps can be reduced by unitizing the two types of pumps, and the space required for installation on a vehicle or the like can be reduced.

However, the two types of pumps operate at different times from each other due to the difference in their intended functions. One anti-skid pump operates during anti-skid control, while the other hydro-booster pump operates when a predetermined pressure is not stored in the accumulator, regardless of anti-skid control. Therefore, it is necessary to invalidate the operation of the pump for the hydro booster at the time of anti-skid control so that unnecessary pressure accumulation in the accumulator is not performed. Here, the term "ineffective" means that the components such as the piston of the pump are moving, but the pump does not accumulate pressure on the accumulator.

As the invalidating means, the above-mentioned publication discloses a technique of providing an electromagnetic valve on the discharge side of a pump for a hydro booster. This solenoid valve is closed when the accumulator does not have a predetermined pressure accumulation, but opens when the predetermined pressure has been accumulated, to return the liquid discharged from the pump to the reservoir.

(Problems to be Solved by the Invention) In the conventional invalidating means, when the solenoid valve is closed and the discharge pressure of the pump is stored in the accumulator, a high pressure is applied to the valve portion. Therefore, if the shutoff capability of the solenoid valve is low, there is a possibility that a pressure accumulation failure may occur due to leakage. In order to prevent leakage, it is necessary to provide the solenoid valve with a sufficient shutoff capability, but the valve is accordingly enlarged.

The present invention has been made in consideration of the above points, and has as its object to provide a technique capable of disabling the operation of a hydro booster pump without requiring a large-sized valve.

(Summary of the Invention) In the present invention, as a means for disabling the operation of the hydro booster pump, a valve device for shutting off communication between the reservoir and the suction side of the hydro booster pump is provided. .

If a predetermined pressure is accumulated in the accumulator during the anti-skid control, the valve device closes and shuts off the communication between the reservoir and the suction side of the pump. As a result, the working fluid is not supplied from the reservoir to the pump, and the pump for the hydro booster is disabled. Since the valve device receives only the suction pressure of the pump, no large shutoff capability is required, and a simple shutoff valve can be used.

In particular, in the present invention, an anti-skid control start signal and a detection signal indicating that the accumulator pressure is insufficient are used as the switching control signal of the valve device. That is, in the brake device including the anti-skid hydraulic pressure control device, the switching control of the valve device is performed in view of the anti-skid control, so that the switching control of the valve device can be simplified.

(Embodiment) FIG. 1 shows an overall circuit configuration of a brake device according to the present invention, and mainly illustrates a sectional structure of a pump portion. FIG. 2 shows the arrangement of the pump.

First, the part of the brake circuit from the master cylinder to the wheel cylinder will be clarified with reference to FIG.

The brake circuit of the brake device 10 includes a tandem-type master cylinder 12 as a brake pressure source. The master cylinder 12 is integrally formed with a hydro booster 20 for assisting the operation and a reservoir 14 for storing a hydraulic fluid. The hydro booster 20 is a known type that includes a supply valve 22 and a discharge valve 23 in addition to the cylinder body 21. The hydro booster 20 closes the discharge valve 23 from the open state to the supply valve 22 in response to the depression of the brake pedal 11.
From the closed state to the open state, and receives the supply of the pressure liquid from the auxiliary pressure source circuit described later to assist the operation of the master cylinder 12.

The two brake circuits are front and rear piping. One discharge port 12a of tandem type master cylinder 12
From there, a brake pipe 31 extends, which is divided into two branch pipes 31a, 31b from the middle, and each branch pipe 31a, 31b communicates with each wheel cylinder of the front brakes 33FR, 33FL.
At the same time, a brake pipe 32 extends from another discharge port 12b of the master cylinder 12, and the
The branch pipes are divided into two branch pipes 32a and 32b, and each branch pipe 32a and 32b communicates with each wheel cylinder of the rear brakes 33RR and 33RL.

And each branch pipe 31a, 31b of such a brake circuit;
There is an anti-skid hydraulic pressure control device in the middle of 32a and 32b.
The anti-skid fluid pressure control system is equipped with front and rear brakes 33F
R, 33FL; 33RR, 33RL have the same configuration. To that end, in addition to the pump described later, each branch pipe 31a, 31b; 32a,
A three-position three-way electromagnetic switching valve 35 located in the middle of 32b,
It includes a brake release control valve 36 connected in parallel to the electromagnetic switching valve 35, and a low-pressure reservoir 37 for storing the hydraulic fluid released through the electromagnetic switching valve 35. In this example, one low-pressure reservoir 37 having one left and right brake in both front and rear is commonly used. In addition, the electromagnetic switching valve
Reference numeral 35 denotes a current control type switching valve, which responds to a control signal from an electronic controller (not shown) which receives a signal from a wheel speed sensor or the like and controls each valve and pump based on the signal. The state is switched to the holding, loosening or putting state. The solenoid-operated switching valve 35 is normally in the position shown in FIG.

Next, an auxiliary pressure source circuit for supplying a hydraulic pressure to the hydro booster 20 is mainly composed of an accumulator 40.
As the accumulator 40, any of a bladder type, a piston type and a metal bellows type can be used, but in many cases, a bladder type is used. The accumulator 40 receives a supply of pressurized liquid from a pump and accumulates the pressurized liquid. Associated with the accumulator 40 is a pressure switch 42 and a relief valve 44. Pressure switch 42
Communicates in the middle of the pipe 43 on the discharge side of the pump to detect the accumulated pressure in the accumulator 40. The accumulated pressure is determined by the electrical contacts 42a, 42a corresponding to the upper limit pressure, the lower limit pressure, and the no pressure.
It can be seen from the on-off state of b and 42c. Pressure switch 4
The signal from each of the two contacts is sent to a controller (not shown) and used for control for enabling or disabling the operation of the pump. On the other hand, the relief valve 44 is located in the middle of a pipeline 46 connecting the pipeline 43 on the discharge side and the pipeline 45 on the suction side of the pump. When the temperature increases and the accumulated pressure in the accumulator 40 exceeds its capacity, the relief valve 44 returns the excess hydraulic pressure to the reservoir 14 through the pipe 45.

Now, the brake device 10 includes an anti-skid pump for pressurizing the hydraulic fluid in the low-pressure reservoir 37 and a reservoir.
There are two types of pumps, a hydro booster pump that pressurizes the working fluid in 14 and sends it to the accumulator 40. These two types of pumps have a common electric motor 50 as a prime mover and a common housing. Inside the housing 54, a drive shaft 51 of the electric motor 50 extends from top to bottom in the drawing, and an eccentric cam 52 is supported in the middle of the drive shaft 51. The eccentric cam 52 serves as a master and drives a plunger of each pump as a slave.

The low-pressure reservoir 37 in the anti-skid hydraulic pressure control device
Since there are two pumps according to the front and rear pipes, the two anti-skid pumps are the first pump 61 and the second pump 62.
Therefore, in the brake device 10, in consideration of the balance of the force around the cam, the other hydro booster pump is also used as the first pump.
Pump 71 and the second pump 72. Second
The figure shows the arrangement of each pump. Each pump is in a cross-shaped arrangement, and the first pump and the second pump are separated from each other around one eccentric cam 52 for both the anti-skid and the hydro booster. 180 ゜ apart. Of course,
The number of cams is two, the first pump 61 and the second pump 62 for anti-skid are arranged 180 ° apart around one cam, and one or two hydro booster pumps are arranged around the other cam. It can also be arranged.

The structure itself of the two types of pumps is the same as the conventional one. FIG. 1 shows the cross-sectional structure of the pump part displaced by 90 °. At the center of the inside of the housing 54, which is the main body, there is a chamber 55 in which the drive shaft 51 of the electric motor 50 extends, and there are four cylinder holes perpendicular to the chamber 55.
Each pair of cylinder holes is on a straight line, and in one cylinder hole 56, pumps 71 and 72 for hydro booster
Pumps 61 and 6 for anti-skid are inserted into the other cylinder bore 58.
2 are each configured.

Looking at the anti-skid pump 61 located on the left side of the figure (the same applies to the other pump 62), in the cylinder hole 58, there are cylinder members 63a, 63b integrated with each other by caulking. The plug 64 supports the cylinder members 63a and 63b so as to be sandwiched between the plug 64 and the step of the housing 54. Then, the integrated cylinder member 63
A pair of check valves 65a and 65b are provided inside a and 63b, and the space therebetween is a volume chamber 66 of the pump. The volume chamber 66 communicates with the discharge ports 61o and 62o of the housing 54 through a check valve 65a and a passage 67a provided in the cylinder member 63a on the one hand, and the check valve 65b and a passage 68a in the plunger 68 on the other hand. The suction ports 61i, 62i are communicated through the like. Therefore, when the plunger 68 reciprocates, the hydraulic fluid reaches the volume chamber 66 through the suction ports 61i and 62i, and the hydraulic fluid is pressurized in the volume chamber 66 and sent to the brake circuit from the discharge ports 61o and 62o. In addition,
Each suction port 61i, 62i communicates with the low-pressure reservoir 37 through a line 48 and a check valve 38, and each discharge port 61o, 62o
It communicates with the brake lines 31 and 32 through a line 49 and a check valve 39.

On the other hand, the hydro booster pump 71
(The same applies to the other pump 72.) Looking at the cylinder hole 56, there is a cylinder member 73 and a valve housing 74, and one end of the valve housing 74 is connected to a cap member.
75 support. There is a check valve 76 in the valve housing 74 and a volume chamber 78 between it and the plunger 77. On the other hand, the discharge chamber 71 of the housing 54 portion passes through a check valve 76, a passage 74a provided in the cap member 74, and the like.
o, 72o, and on the other hand a passage 77a in the plunger 77,
It communicates with the suction port 71i through a chamber 55 or the like in the center of the housing 54. Then, when the plunger 77 reciprocates, the hydraulic fluid reaches the volume chamber 78 through the suction port 71i, and the hydraulic fluid is pressurized in the volume chamber 78 and sent from the discharge ports 71o, 72o to the accumulator 40 side. .

The discharge port 7 of the pump 71, 72 for such a hydro booster
Needless to say, 1o and 72o communicate with the accumulator 40 through the conduit 43, and the suction port 71i communicates with the reservoir 14 through the conduit 45, respectively. In the brake device 10, while the suction port 71i is in communication with the reservoir 14, the electromagnetic switching valve 80
Is provided. The switching valve 80 is a two-position valve, and can switch between a shut-off position A and a communication position B.
The switching valve 80 is normally at the communication position B, but is controlled to switch to the shut-off position A when a predetermined pressure is accumulated in the accumulator 40 during the anti-skid control.
Therefore, an anti-skid start signal from the controller and a signal from the pressure switch 42 are used as control signals for the switching valve 80, respectively.

If the switching valve 80 is in the shut-off position A, the hydraulic fluid is not supplied from the reservoir 14 to the hydro booster pumps 71 and 72, so that the operation of those pumps can be invalidated. The switching valve 80 can be provided at an appropriate position in the portion of the pump suction port 71i, in the middle of the pipe line 45, and further in the portion of the reservoir 14. In any case, the switching valve 80 is provided with pumps 71 and 72 for the hydro booster.
Is located on the suction side, so that it does not receive a large hydraulic pressure unlike the case where it is provided on the discharge side. Therefore, the switching valve 80 does not need to have a large shut-off capability, and an ordinary small valve device can be used.

When the hydro booster pumps 71 and 72 are operating effectively and accumulating pressure in the accumulator 40, the plungers 68 of the anti-skid pumps 61 and 62 also reciprocate. However, when the anti-skid control is not performed, the hydraulic fluid in the low-pressure reservoir 37 is empty.
The liquid pressurized by 61 and 62 is not sent to the brake circuits 31 and 32 side.

In the embodiment shown in the figure, a low-pressure reservoir 37 to which a back pressure is applied by a spring 37a is used as a loosening reservoir for anti-skid control. However, in the case where a reservoir having a structure that does not apply back pressure is used instead of the low-pressure reservoir 37, the anti-skid pumps 61 and 62 can be invalidated by invalidating means similar to the valve device 80 described above. .

(Effects of the Invention) In the present invention, as means for disabling the operation of the hydro booster pumps 71 and 72, a valve for shutting off communication between the reservoir 14 and the suction side of the hydro booster pumps 71 and 72 is provided. Since the device (switching valve 80) is provided, the valve device used there can be reduced in size,
The advantage of the technology of using the same prime mover 50 for the two types of pumps can be effectively used.

[Brief description of the drawings]

 FIG. 1 is an overall view showing an embodiment of the present invention, and FIG. 2 is a view showing an arrangement of a pump. 10 ... Brake device, 12 ... Master cylinder, 14 ... Reservoir, 20 ... Hydro booster, 31,32 ... Brake piping, 35 ... Electromagnetic switching valve (anti-skid control valve), 40 ... Accumulator, 42 … Pressure switch, 61,62… Anti-skid pump, 71,72… Hydro booster pump, 80… Electromagnetic switching valve (valve device, disabling means).

Claims (1)

(57) [Claims] A brake circuit provided with an anti-skid hydraulic pressure control device between a master cylinder and a wheel cylinder for controlling the hydraulic pressure on the wheel cylinder side in response to a command from a controller for monitoring the condition of the wheel; An auxiliary pressure source circuit for supplying hydraulic pressure to a hydro booster that assists the operation of the master cylinder, wherein the anti-skid hydraulic pressure control device is for an anti-skid that pressurizes hydraulic fluid discharged from the wheel cylinder. Having a pump,
Further, the auxiliary pressure source circuit has a hydraulic booster pump that pressurizes the hydraulic fluid stored in the reservoir and sends the hydraulic fluid to an accumulator, and a motor that commonly drives the anti-skid pump and the hydraulic booster pump. And a disabling means for disabling the operation of the hydro-booster pump when a predetermined pressure is accumulated in the accumulator, wherein the disabling means includes suction of the reservoir and the hydro-booster pump. A valve device that is controlled to switch to a communication position communicating between them or a blocking position that blocks communication therebetween, the valve device is usually in the communication position, Of the anti-skid control start signal and the accumulation of pressure in the accumulator are insufficient. Brake and wherein the switch to the closed position based on the signal.