JP5194948B2 - Brake hydraulic pressure supply device - Google Patents

Description

  The present invention relates to a brake hydraulic pressure supply device that adjusts a hydraulic pressure supplied from an auxiliary hydraulic pressure source to a value corresponding to a brake operation by a pressure adjusting device and supplies the pressure to a wheel cylinder of a vehicle.

  As a conventional example of a hydraulic brake device for a vehicle, for example, there is one disclosed in Patent Document 1 below. The hydraulic brake device described in the literature 1 employs a brake hydraulic pressure supply device (hereinafter simply referred to as a hydraulic pressure supply device) that combines a master cylinder and a pressure adjusting device, and is generated by the master cylinder. The hydraulic pressure (master cylinder pressure) is supplied to one system of wheel cylinders, and the hydraulic pressure supplied from the auxiliary hydraulic pressure source is adjusted by the pressure adjusting device of the hydraulic pressure supply device and supplied to the wheel cylinder of the other system.

  The hydraulic pressure supply device employed in the hydraulic brake device includes a pressure adjusting piston that propels the hydraulic pressure generated by the master cylinder at the rear surface, a pressure adjusting chamber that faces the front surface of the pressure adjusting piston, and a spool cylinder. The pressure regulator is provided with a spool valve body slidably inserted in the valve body and a valve portion formed between a shoulder portion of the spool valve body and the spool cylinder. In this pressure regulating device, the pressure regulating piston pushes and moves the spool valve body, the opening degree of the valve portion is adjusted by the displacement of the spool valve body, and the hydraulic pressure supplied from the auxiliary hydraulic pressure source by the valve portion is adjusted. The pressure is adjusted to a value proportional to the brake operation amount and output to the pressure adjusting chamber.

In addition, a power chamber for introducing the hydraulic pressure from the pressure regulating chamber is provided, and the brake operating force is amplified by the hydraulic pressure from the pressure regulating chamber introduced into the power chamber and added to the master cylinder. The pressure adjustment piston is operated with the generated hydraulic pressure. Therefore, the hydraulic pressure regulated by the pressure regulating device is in accordance with the brake operation amount. The hydraulic pressure generated in the master cylinder is supplied to one system wheel cylinder, and the hydraulic pressure adjusted by the pressure adjusting device is supplied to the other system wheel cylinder.
JP 2001-138894 A

  The hydraulic pressure supply device of the hydraulic brake device disclosed in the above-mentioned Patent Document 1 generates a master cylinder pressure according to the brake operation, the pressure adjusting device operates according to the hydraulic pressure, and an auxiliary hydraulic pressure source High pressure brake fluid is introduced. At this time, when a strong brake brake operation is performed, the valve portion of the pressure regulator opens suddenly and a large amount of brake fluid passes through the pressure regulator. As a result, cavitation occurs, which can be heard as an operating sound, causing discomfort to the driver of the car.

  With respect to this problem, the above-mentioned Patent Document 1 discloses a flow path (flow path between the auxiliary hydraulic pressure source and the pressure regulating chamber) formed between the outer periphery of the spool valve body and the inner peripheral surface of the spool cylinder. Although it has been proposed to suppress cavitation by avoiding sudden area changes, this method cannot prevent the introduction of a large amount of brake fluid when the brake is operated strongly. Insufficient suppression.

  The present invention relates to a pressure adjusting device that adjusts and outputs a high hydraulic pressure supplied from an auxiliary hydraulic pressure source to a value corresponding to a brake operation, and a liquid chamber including a power chamber for amplifying a force generated by the brake operation. An object of the present invention is to make it possible to effectively suppress the operation noise caused by cavitation by a method that does not cause complicated structure and increase in cost for a hydraulic pressure supply device for a pressure brake device.

In order to solve the above-described problems, in the present invention, a pressure adjusting piston that operates by receiving a force generated by a brake operation, a pressure adjusting chamber that faces the front surface of the pressure adjusting piston, and a spool cylinder that is slidably inserted. A pressure regulating device comprising a spool valve body, a valve portion formed between a shoulder portion of the spool valve body and the spool cylinder, and a power chamber for introducing hydraulic pressure from the pressure regulating chamber; Have
The spool valve body is pushed by the pressure adjusting piston to adjust the opening of the valve portion, and the hydraulic pressure supplied from the auxiliary hydraulic pressure source is adjusted to a value proportional to the brake operation by adjusting the opening. A hydraulic pressure supply device that is supplied to the pressure regulating chamber and that assists the operation of the pressure regulating piston by the hydraulic pressure from the pressure regulating chamber introduced into the power chamber. In addition, the flow path for outputting the hydraulic pressure from the pressure regulating chamber of the apparatus is provided with a throttle part for partially reducing the passage area of the flow path, and the outer circumferential surface of the pressure regulating piston and the pressure regulating piston An annular gap is provided between the inner peripheral surface of the cylinder hole into which the cylinder is slidably inserted, and the throttle part is configured by the annular gap, and the size of the throttle part varies depending on the movement of the pressure adjusting piston. I did it .

  In the fluid supply device of the present invention, the flow rate of the brake fluid output from the pressure regulating chamber is throttled by the throttle portion provided in the flow path from the pressure regulating chamber. Therefore, back pressure is generated in the pressure adjusting chamber at the initial stage of the brake operation, and the pressure increase gradient of the hydraulic pressure introduced from the auxiliary hydraulic pressure source to the pressure adjusting chamber via the valve portion is also increased. The back pressure of the pressure regulating chamber acts as a return force to the pressure regulating piston to slow down the movement (advance) of the pressure regulating piston. For this reason, the opening amount of the valve portion of the pressure regulating device, that is, the pressure regulating chamber The amount of brake fluid introduced is restricted, and high fluid pressure is not suddenly introduced from the auxiliary fluid pressure source at the initial stage of brake operation. The brake fluid returns through the throttle even when the brake is depressurized so that the throttle effect by the throttle and the rapid return of high hydraulic pressure are suppressed, thereby suppressing cavitation and no throttle. Compared with the hydraulic pressure supply device, the operation noise is suppressed and the driver is less likely to feel uncomfortable.

  Embodiments of the present invention will be described below with reference to FIGS. FIG. 1 shows an example of a vehicle hydraulic brake device employing the hydraulic pressure supply device of the present invention. The hydraulic brake device shown in the figure generates a high hydraulic pressure by a brake operating member (that is, a brake pedal in the drawing) 1, a hydraulic pressure supply device 5 that combines a master cylinder 2, a pressure regulator 3, and a booster mechanism 4. The auxiliary hydraulic pressure source 6, the hydraulic pressure control unit 7, and wheel cylinders 8 and 9 (one for the front wheel and one for the rear wheel are shown in the figure) attached to each wheel of the vehicle are combined. ing. The illustrated auxiliary hydraulic pressure source 6 is a combination of a motor-driven pump 6a and a pressure accumulator 6b.

  The master cylinder 2 is configured by assembling a master piston 2a and a return spring 2b for returning the master piston into the cylinder hole 10a of the cylinder body 10, and a pressure corresponding to the brake operation amount of the driver is applied to the pressure chamber R2. generate.

  The pressure regulating device 3 is also provided inside the cylinder hole 10a. The pressure regulating device 3 includes a pressure regulating piston 3a having a rear surface facing the pressure chamber R2, a spool valve body 3b disposed in front of the piston (leftward in the drawing) and pushed by the pressure regulating piston 3a, And a return spring 3c for returning the spool valve body 3b. The pressure adjusting device 3 is formed between the shoulder of the outer periphery of the spool valve body 3b and the spool cylinder 3d by the operation of the spool valve body 3b being pushed by the pressure adjusting piston 3a and moving forward in the figure. Valve portion 3e is opened, the high-pressure brake fluid supplied from the auxiliary fluid pressure source 6 is regulated, and the regulated fluid pressure (regulator fluid pressure) is introduced into the pressure regulating chamber R3, and further the pressure regulating chamber It is introduced into the reaction force chamber R4 and the power chamber R1 via the flow path 17 through which the output hydraulic pressure from R3 passes.

  The hydraulic pressure supply device 4 includes a push rod 11 connected to the brake operation member 1, and the driver's brake operation force applied to the brake operation member (brake pedal) 1 is the push rod 11 and the power piston 4a. It is transmitted via. The master piston 2a receives the force and moves forward to pressurize the brake fluid in the pressure chamber R2.

  The hydraulic pressure supply device 4 is used when a brake assist function is required, and the hydraulic pressure supplied from the auxiliary hydraulic pressure source 6 is adjusted by the pressure adjusting device 3 according to the driver's brake operation. The pressure is adjusted to the value and output (the pressure after pressure adjustment is referred to as regulator fluid pressure), and the regulator fluid pressure is introduced into the power chamber R1 to act on the power piston 4a of the booster mechanism 4 and the master piston 2a Help advance. As a result, a force obtained by adding the assisting force of the power piston 4a to the brake operation force by the driver acts on the master cylinder 2 to generate a desired brake fluid pressure in the pressure chamber R2.

  In FIG. 1, 12 is a center valve mechanism for communicating the pressure chamber R2 with the liquid chamber R5 communicated with the reservoir 13 when the master piston 2a returns to the original position, 14 is an input member provided as necessary, and 15 is power. This is a contact member that transmits the forward thrust of the piston 4a to the master piston 2a. The master piston 2a and the power piston 4a may be formed integrally with the contact member 15 omitted.

  Further, in the illustrated hydraulic pressure supply device, a boosting characteristic switching mechanism that introduces the hydraulic pressure from the pressure regulating chamber R3 into the reaction force chamber R4 and applies it to the front end of the spool valve element 3b via the elastic reaction force disk 16 is provided. Is installed. In the illustrated apparatus, the hydraulic pressure is supplied from the pressure regulating chamber R3 to the power chamber R1 via the reaction force chamber R4, but the flow path through which the output hydraulic pressure from the pressure regulating chamber R3 passes is bifurcated in two directions. It is also possible to bring one of the branch paths into the power chamber R1 and the other into the reaction chamber R4.

  The boosting characteristic switching mechanism described here is more effective when the hydraulic pressure introduced from the pressure adjusting chamber R3 to the reaction force chamber R4 is larger than a predetermined value, compared to when the hydraulic pressure is smaller than the predetermined value. This is a mechanism for giving the characteristic that the step-up gradient is gentle, but it is not an essential element. In a device without the mechanism, the reaction force chamber R4 is omitted.

  The hydraulic pressure supply device configured as described above moves to the balance point of the pressure (the hydraulic pressure of the pressure chamber R2 and the pressure adjustment chamber R3) received by the pressure adjustment piston 3a facing the front and rear surfaces. The spool valve body 3b follows and the opening degree of the valve portion 3e is adjusted. For this reason, the regulator hydraulic pressure introduced into the pressure regulating chamber R3 is in accordance with the driver's brake operation, and the power piston 4a moves forward with the regulator hydraulic pressure, and the thrust and the driver's brake operating force are increased. The combined force is applied to the master piston 2a, and the brake fluid pressure generated in the pressure chamber R2 is amplified. Therefore, it is possible to generate a braking force that is greater than the braking force that can be generated by the driver's operating force.

  In the hydraulic brake device including the hydraulic pressure supply device having the above configuration, the hydraulic pressure generated in the master cylinder 2 and the hydraulic pressure supplied from the auxiliary hydraulic pressure source 6 are used for braking. In general, the brake system of the vehicle is divided into two systems, and the hydraulic pressure generated in the pressure chamber R2 is supplied to the wheel cylinder 8 of one system via the hydraulic control unit 7, The regulator hydraulic pressure regulated by the pressure regulating device 3 flows through the power chamber R1 and the hydraulic pressure control unit 7, and is output toward the wheel cylinder 9 of the other system. The hydraulic pressure control unit 7 is a well-known device including an electromagnetic valve for pressure increase / decrease that controls the hydraulic pressure of the wheel cylinders 8 and 9 based on a command from an electronic control device (not shown).

  The part described above is well known. In other words, the diaphragm 18 described below is a characteristic part of the present invention. In the hydraulic pressure supply device of FIG. 1, as shown in an enlarged view in FIG. 2, an annular gap g is provided on the outer periphery of the pressure regulating piston 3a, and the annular shape serving as the starting end of the flow path 17 (the outlet from the pressure regulating chamber R3). The narrowing portion 18 is constituted by the gap g. Assuming that the piston diameter of the pressure regulating piston 3a is, for example, 20 mm, the throttle portion 18 is configured with a very small gap having a radius of about 0.2 to 0.3 mm. The overlap of the annular gap g with the flow path 17 is changed by the movement of the pressure adjusting piston 3a. Therefore, the throttle portion 18 constituted by the annular gap g is a variable throttle with a variable throttle amount. The hydraulic pressure from the pressure regulating chamber R3 is output through the throttle portion 18, and a back pressure is generated in the pressure regulating chamber R3 at the initial stage of the brake operation due to the throttle effect by the throttle portion 18, and assists via the valve portion 3e. The pressure increase gradient of the fluid pressure introduced from the fluid pressure source 6 to the pressure adjusting chamber R3 is also increased. The back pressure in the pressure regulating chamber R3 slows down the movement of the pressure regulating piston 3a. For this reason, the rapid opening of the valve portion 3e of the pressure regulating device 3 is suppressed, and the amount of brake fluid introduced into the pressure regulating chamber R3 is restricted. Thus, the high hydraulic pressure is not suddenly introduced from the auxiliary hydraulic pressure source at the initial stage of the brake operation. Further, the same effect is obtained when the brake is released, and the purpose of suppressing the operating noise by suppressing cavitation is achieved.

The throttle portion 18 is preferably arranged at a position as close as possible to the pressure regulating chamber R3. That is, as the distance from the pressure adjusting chamber R3 to the throttle portion installation point becomes shorter, the pressure increasing gradient of the pressure adjusting chamber R3 becomes higher and the effect of suppressing the movement of the pressure adjusting piston at the initial stage of the brake operation is increased.

In addition, the flow path 17 through which the output hydraulic pressure from the pressure regulating chamber R3 passes is bifurcated in two directions so that one of the branch paths reaches the power chamber R1 and the other reaches the reaction force chamber R4, or the pressure regulating chamber R3. It is also possible to adopt a structure in which the output hydraulic pressure from is first introduced into the power chamber R1, and then the pressure is supplied from the power chamber R1 to the reaction force chamber R4.

  Although the illustrated hydraulic pressure supply apparatus has a master cylinder, the hydraulic pressure from the auxiliary hydraulic pressure source can be obtained by a structure that does not use the master cylinder by directly contacting the power piston 4a with the pressure regulating piston 3a. The present invention is also applied to a hydraulic pressure supply device that regulates and outputs a value corresponding to a brake operation.

Sectional drawing which shows an example of the hydraulic brake apparatus which employ | adopted the hydraulic pressure supply apparatus of this invention FIG. 1 is an enlarged sectional view showing the main part of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Brake operation member 2 Master cylinder 2a Master piston 2b Return spring 3 Pressure regulating device 3a Pressure regulating piston 3b Spool valve body 3c Return spring 3d Spool cylinder 3e Valve part 4 Booster mechanism 4a Power piston 5 Hydraulic pressure supply apparatus 6 Auxiliary hydraulic pressure Source 6a Pump 6b Pressure accumulator 7 Hydraulic control unit 8, 9 Wheel cylinder 10 Cylinder body 10a Cylinder hole 11 Push rod 12 Center valve mechanism 13 Reservoir 14 Input member 15 Contact member 16 Reaction force disk 17 Flow path 18 Restriction part R1 Power Chamber R2 pressure chamber R3 pressure regulating chamber R4 reaction force chamber R5 liquid chamber g annular gap

Claims (1)

The pressure adjusting piston (3a) that operates by receiving the force generated by the brake operation, the pressure adjusting chamber (R3) facing the front surface of the pressure adjusting piston (3a), and the spool cylinder (3d) are slidably inserted. A pressure regulating device (3) comprising a spool valve body (3b) and a valve portion (3e) formed between the shoulder portion of the spool valve body (3b) and the spool cylinder (3d); A power chamber (R1) for introducing hydraulic pressure from the pressure regulating chamber (R3),
The spool valve body (3b) is pushed and moved by the pressure regulating piston (3a), and the valve portion (3
The opening degree of e) is adjusted, and by adjusting the opening degree, the hydraulic pressure supplied from the auxiliary hydraulic pressure source (6) is adjusted to a value proportional to the brake operation and supplied to the pressure adjusting chamber (R3). Furthermore, in the brake hydraulic pressure supply device in which the operation of the pressure regulating piston (3a) is assisted by the hydraulic pressure from the pressure regulating chamber (R3) introduced into the power chamber (R1),
The flow path (17) for outputting the hydraulic pressure from the pressure regulating chamber (R3) is provided with a throttle portion (18) for partially reducing the passage area of the flow path , and further, the pressure regulating piston (3a) An annular gap (g) is provided between the outer circumferential surface of the cylinder and the inner circumferential surface of the cylinder hole (10a) into which the pressure adjusting piston (3a) is slidably inserted, and the throttle portion is formed by the annular gap (g). The brake hydraulic pressure supply device according to claim 18, wherein the size of the throttle portion (18) varies with the movement of the pressure regulating piston (3a) .

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