JPH06135308A - Valve mechanism - Google Patents

Abstract

PURPOSE:To provide a valve mechanism, by which a pressure rise rate can be controlled regardless of the difference in the pressure between caliper pressure and master pressure at the time of switching from anti-lock control to normal control. CONSTITUTION:A cut valve 96 is separated from a seated part 92 by stopping an expander piston 72 at a predetermined point. An output port 80 communicating with am input port 78, which is communicated with a master cylinder and with a caliper cylinder, is communicated only by an orifice 98, and the brake pressure rises at a regulated pressure rise rate. Since the elastic force of a coil spring 104, which is energized downward is larger than that of a coil spring 102, which is energized upward, even the pressure difference between an input port 78 and the output port 80 is reduced, there is no possibility of the orifice valve 100 being separated from the seated part 94, and the pressure rise rate of the caliper pressure can thus be controlled stably.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a valve mechanism for controlling brake pressure in order to carry out antilock control in automobiles and motorcycles. More specifically, it relates to a valve mechanism which is based on a pressure difference between a master cylinder and a caliper cylinder. And a valve mechanism that enables stable brake control.

[0002]

2. Description of the Related Art In automobiles and motorcycles, a brake control device having an antilock modulator is used to control the brake pressure.

For example, as shown in FIG. 9, an anti-lock control modulator incorporated in a motorcycle communicates with a master cylinder that converts a brake operation command generated by a driver's lever operation or pedal operation into hydraulic pressure. An input hydraulic chamber 2 and an output hydraulic chamber 4 communicating with a caliper cylinder for generating a braking force on the brake discs of the wheels,
A cut valve 6 that connects and disconnects the input hydraulic chamber 2 and the output hydraulic chamber 4, and a cut valve 6 that is disposed on the output hydraulic chamber 4 side to close the cut valve 6 at the time of antilock braking. And an expander piston 8 for increasing the volume and decreasing the oil pressure.

In this case, in the modulator described above, in order to prevent the wheels from being locked during braking, the expander piston 8 is displaced to increase the volume of the output hydraulic chamber 4, thereby increasing the braking force by the caliper cylinder. (Caliper pressure) is reduced. When the danger of the locked state is avoided, the cut valve 6 is displaced upward by bringing the expander piston 8 into contact with the cut valve 6 to displace the cut valve 6, thereby separating the cut valve 6 from the seat portion 12. The input hydraulic chamber 2 and the output hydraulic chamber 4 are communicated with each other to perform normal braking.

[0005]

However, in the above prior art, when shifting from antilock control to normal control during vehicle body braking, the expander piston 8 is displaced at the maximum speed by the rotary drive source and the cut valve 6 is operated. Open up. Therefore, as shown by the broken line between BC in FIG.
The caliper pressure P1 rapidly increases toward the pressure (master pressure) P0 generated in the master cylinder at the maximum boost rate. Therefore, it has been pointed out that the behavior of the vehicle body becomes large and the driving feeling is deteriorated.

Therefore, a cut valve as shown in FIG. 11 has been proposed. That is, when shifting from the antilock control to the normal control, first, the stem 14 is displaced upward by the expander piston 8 to displace the spherical body 16 upward so as to be separated from the seating portion 18, and the gap 20 is formed. The input oil pressure chamber 2 and the output oil pressure chamber 4 are communicated with each other via the. Therefore, the caliper pressure P1 can first regulate the boost rate by the gap 20 as shown by the broken line between BD in FIG. In this case, sphere 16
The elastic force of the coil spring 22 that urges the cut valve 6 increases, and the cut valve 6 is urged upward. That is, in the cut valve 6, the elastic force of the coil spring 22 becomes larger than the elastic force of the coil spring 10 and the hydraulic pressure difference between the input hydraulic chamber 2 and the output hydraulic chamber 4, and the cut valve 6 is separated from the seat portion 12. . By the way, as described above, the spherical body 16 is seated on the seat portion 18 in order to regulate the pressure rising rate.
The condition under which the cut valve 6 is seated on the seat 12 is as follows.

F1-F2 <(P1-P2) × A Here, F1 and F2 are coil springs 2, respectively.
Elastic forces due to 2 and 10, P1 and P2 are pressures of the input hydraulic chamber 2 and the output pressure chamber 4, and A is an effective sectional area of the cut valve 6.

However, the elastic force F1 of the coil spring 22 is larger than the elastic force F2 of the coil spring 10 in order to open the cut valve 6 due to the increase of the elastic force F1 of the coil spring 10 as the sphere 16 rises. (F1> F2) must be set. Therefore, when the hydraulic pressure difference (P1-P2) between the input hydraulic chamber 2 and the output hydraulic chamber 4 decreases due to the gap 20,
Alternatively, if the hydraulic pressure difference (P1-P2) is small from the beginning, the cut valve 6 may be opened, and the pressurization rate may not be regulated.

The present invention has been made to solve this type of problem, and when the antilock control is shifted to the normal control, the caliper pressure is not affected by the pressure difference between the caliper pressure and the master pressure. It is an object of the present invention to provide a valve mechanism capable of controlling the boost rate of the.

[0010]

In order to achieve the above object, the present invention provides an input pressure chamber communicating with a master cylinder for generating a brake pressure based on a brake operation amount, and a caliper cylinder for operating a wheel brake. An output pressure chamber communicating with the output pressure chamber, an adjustment chamber provided between the input pressure chamber and the output pressure chamber, a piston provided in the output pressure chamber so as to move back and forth, and a tip portion of the piston is in contact with each other. For communicating the adjustment chamber and the output pressure chamber by interlocking with each other
A valve body and a second valve body that makes the adjustment chamber and the input pressure chamber communicate with each other by abutting and interlocking movement of the first valve body and both ends of the first valve body and the second valve body. Both ends of the first elastic member for urging the first valve body so as to cut off the communication between the adjustment chamber and the output pressure chamber, and both ends of the second valve body and the input pressure chamber, A second elastic member that blocks communication between the adjustment chamber and the input pressure chamber; and an orifice that communicates between the adjustment chamber and the input pressure chamber, the second elastic member being greater than the first elastic member. It is characterized by a large elastic force.

[0011]

In the valve mechanism of the present invention, when the anti-lock control is shifted to the normal control during braking of the vehicle body, first, the piston is brought into contact with and interlocked with the first valve body to open the first valve body. As a result, the adjustment chamber and the output pressure chamber, which are communicated with each other by the input pressure chamber and the orifice, are communicated with each other, so that the pressure in the output pressure chamber rises at the pressure increasing rate regulated by the orifice.
Thereafter, the piston is further displaced, so that the first valve body comes into contact with the second valve body to open the second valve body. In this process, since the elastic force of the second elastic member that closes the second valve body is larger than the elastic force of the first elastic member that biases the second elastic member in the opening direction, the first valve The second valve body will not be opened even if the pressure difference between the input pressure chamber and the adjusting pressure chamber becomes small until the body comes into contact with the second valve body. Therefore, by controlling the position of the piston, the boost rate can be stably controlled.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A valve mechanism according to the present invention will be described below in detail with reference to the accompanying drawings, with reference to the preferred embodiments.

FIG. 1 is a schematic configuration diagram of a brake control device 30 according to this embodiment, in which a control unit 32 controls a modulator 34 to control a brake pressure to obtain an optimum braking force.

An output signal from a sensor (not shown) or the like is introduced into the control unit 32. In this case, the control unit 32 includes a plurality of arithmetic circuits (not shown) for determining whether to perform antilock control or for obtaining a rotation amount of a DC motor (to be described later) based on the amount of increase / decrease in caliper pressure. Is provided.

The brake device 38 includes a master cylinder 44 driven by a brake lever 42 provided on a handle 40 and a caliper cylinder 4 for braking a front wheel Wf.
6, the master cylinder 44 and the caliper cylinder 46
Are interconnected via a modulator 34.
The master cylinder 44 adjusts the hydraulic pressure under the action of the brake lever 42 and transmits the hydraulic pressure to a cut valve mechanism, which will be described later, while the caliper cylinder 46, based on the hydraulic pressure controlled by the cut valve mechanism. The braking force is applied to the disc plate 48.

The modulator 34 of the front wheels Wf comprises a DC motor 50 and a motor driver 52 for energizing and deenergizing the DC motor 50 to drive and control the DC motor 50. This motor driver 52
The signal derived from the control unit 32 is introduced by being electrically connected to the control unit 32.
A pinion 54 is connected to the drive shaft of the DC motor 50,
The gear 56 meshes with the pinion 54. A crankshaft 58 is fixed to the center of the gear 56, and a crankpin 62 is attached to the crankshaft 58 via a crank arm 60.
Are connected at one end. A crank arm 64 is connected to the other end of the crank pin 62.
A potentiometer 66 for detecting the deviation angle of the crank pin 62 is connected to the.

A cam bearing 68 is rotatably mounted on the outer periphery of the crank pin 62.
8 is pressed upward through the return spring 70. The expander piston 72, which moves up and down under the displacement of the cam bearing 68, comes into contact with the upper surface of the cam bearing 68, and the cut valve mechanism 74 operates under the action of the vertical movement of the expander piston 72. To be done. The cut valve mechanism 74 is arranged in the cut valve storage portion 76 so as to be vertically displaceable, and an input port 78 communicating with the master cylinder 44 is provided on the upper surface of the cut valve storage portion 76, while the cut valve storage portion 76 is provided. An output port 80 that communicates with the caliper cylinder 46 is provided at the connecting portion of the expander piston 72 and the expander piston 72.

The cut valve mechanism 74 is shown in FIGS.
As shown in FIG.
8 to the output port 80 side of the communication hole 90 that reduces the diameter in two stages
And the portions where the diameter of the communication hole 90 is reduced in two steps are designated as seating portions 92 and 94, respectively. In the communication hole 90,
A cut valve 96, which is a sphere, and an orifice 98 inside
The orifice valve 100, which is defined by, is inserted. The cut valve 96 is the orifice valve 10
0 is connected to the coil spring 102, is pressed downward by the elastic force of the coil spring 102, and abuts on the seat portion 92. The orifice valve 100 is connected to the wall surface of the input port 78 by the coil spring 104, is pressed downward by the elastic force of the coil spring 104, and is seated on the seat portion 94. The cut valve 96 is a convex tip portion 10 of the expander piston 72.
When 6 contacts, it is displaced. The elastic force of the coil spring 104 is set to be larger than the elastic force of the coil spring 102.

On the other hand, the master cylinder 44a connected to the brake pedal 43 of the rear wheel Wr and the caliper cylinder 46a connected to the disc plate 48a of the rear wheel Wr are communicated with each other via the modulator 34a of the rear wheel Wr. . The modulator 34a has the same configuration as the modulator 34 described above, and detailed description thereof will be omitted.

The brake control device 3 thus constructed
0 operates as follows.

During normal control, the return spring 70
The crank pin 62 is held at a preset upper limit position by the elastic force of, and the cam bearing 68 mounted on the crank pin 62 is maintained in a state where the expander piston 72 is pushed up. As a result, as shown in FIG. 2, the cut valve 96 and the orifice valve 100 are pushed up by the tip portion 106 of the expander piston 72, and are separated from the seat portions 92 and 94, respectively, so that the input port 78 and the output port 80 communicate with each other. I am letting you.

Then, the master cylinder 44 is urged by gripping the brake lever 42, and the brake pressure generated by the master cylinder 44 is transmitted to the caliper cylinder 46 via the input port 78 and the output port 80. The braking force is applied to the disc plate 48.

When antilock control is performed, the DC motor 50 is driven by the motor driver 52 based on a signal from the control unit 32 to displace the crankpin 62 and resist the elastic force of the return spring 70. The panda piston 72 descends. As a result, the tip end portion 106 of the expander piston 72 is separated from the cut valve 96, and the cut valve 96 and the orifice valve 100 contact the seating portions 92, 94 by the elastic force of the coil springs 102, 104, as shown in FIG. Contact. Therefore, the cut valve 96 blocks communication between the input port 78 and the output port 80. Further, as the expander piston 72 descends, the volume of the output port 80 increases and the caliper pressure decreases.

When the antilock control is returned to the normal control, the DC motor 50 is driven to drive the crank pin 62.
The potentiometer 66 as shown in FIG.
On the basis of the output signal of the output signal, the tip portion 106 of the expander piston 72 contacts the cut valve 96 (crank angle = θ
C, see FIG. 5), the cut valve 96 is stopped before the position (crank angle = θO, see FIG. 5) where the cut valve 96 contacts the orifice valve 100. The crank angle is set to 0 ° at the offset position of the crank pin 62 corresponding to the upper limit position of the expander piston 72, and the lower limit direction is set to be positive.

Therefore, the input port 78 and the output port 80 communicate with each other through the orifice 98, and as shown in FIG.
The caliper pressure rises at a regulated pressure increase rate (hereinafter referred to as an orifice state) than the maximum pressure increase rate (broken line portion). In this case, of the coil springs 102, 104 acting on the orifice valve 100, the elastic force of the coil spring 104 biased downward is the coil spring 1.
Since it is larger than the elastic force of 02, the orifice valve 100 will not be separated from the seating portion 94 even if the hydraulic pressure difference between the input port 78 and the output port 80 becomes small.

When returning from the antilock control to the normal control at the maximum boosting rate, the rotation amount of the DC motor 50 is increased and the crank pin 62 is displaced to the crank angle θO or more (FIG. 5, (Refer to the broken line portion), the cut valve 96 and the orifice valve 100 are brought into contact with each other and pressed upward to separate the orifice valve 100 from the seat portion 94, and the caliper pressure is restored at the maximum boosting rate.

Further, in the case of precisely controlling the boost rate, for example, as shown in FIG. 7, the orifice state (see FIG. 4) and the antilock control state (see FIG. 3) are set in an appropriate pattern. By performing motor control based on this and displacing the crank pin 62, it is possible to achieve a desired boost rate as shown in FIG.

As described above, in the brake control system according to this embodiment, the cut valve mechanism 74 can control the opening and closing of the cut valve 96 and the orifice valve 100 without being influenced by the hydraulic pressure difference between the input port 78 and the output port 80. Therefore, the boost rate can be set to a desired rate, and precise brake control can be performed.

[0029]

According to the valve mechanism of the present invention, the following effects can be obtained.

That is, when shifting from the antilock control to the normal control during vehicle body braking, first, the first valve body is opened by the piston coming into contact with and interlocking with the first valve body.
As a result, the adjustment chamber and the output pressure chamber, which are communicated with each other by the input pressure chamber and the orifice, are communicated with each other, so that the pressure in the output pressure chamber rises at the pressure increasing rate regulated by the orifice. Thereafter, the piston is further displaced, so that the first valve body comes into contact with the second valve body to open the second valve body. In this case, since the elastic force of the second elastic member that closes the second valve body is selected to be larger than the elastic force of the first elastic member that urges the second elastic member in the opening direction, Until the first valve body comes into contact with the second valve body, the second valve body will not be opened even if the pressure difference between the input pressure chamber and the adjustment pressure chamber becomes small. Therefore, by controlling the position of the piston, the boost rate can be stably controlled. Further, by providing the orifice inside the second valve body, there is an advantage that the valve mechanism can be downsized.

[Brief description of drawings]

FIG. 1 is an overall configuration explanatory diagram of a brake control device to which a valve mechanism according to the present invention is applied.

FIG. 2 is an explanatory diagram of an operating state of the valve mechanism according to the present invention.

FIG. 3 is an explanatory diagram of an operating state of the valve mechanism according to the present invention.

FIG. 4 is an explanatory diagram of an operating state of the valve mechanism according to the present invention.

FIG. 5 is an explanatory view of a crank angle control state of the valve mechanism according to the present invention.

FIG. 6 is an explanatory view of a caliper pressure increase rate control of the valve mechanism according to the present invention.

FIG. 7 is an explanatory diagram of a crank angle control state of the valve mechanism according to the present invention.

FIG. 8 is an explanatory diagram of a boost rate control of the caliper pressure of the valve mechanism according to the present invention.

FIG. 9 is a structural explanatory view of a valve mechanism according to a conventional example.

FIG. 10 is an explanatory diagram of a boost rate control of a caliper pressure of a valve mechanism according to a conventional example.

FIG. 11 is a structural explanatory view of a valve mechanism according to a conventional example.

[Explanation of symbols]

 30 ... Brake control device 32 ... Control unit 34 ... Modulator 44 ... Master cylinder 46 ... Caliper cylinder 50 ... DC motor 62 ... Crank pin 72 ... Expander piston 74 ... Cut valve mechanism 78 ... Input port 80 ... Output port 96 ... Cut valve 98 ... Orifice 100 ... Orifice valve 102, 104 ... Coil spring

Claims (2)

[Claims] 1. An input pressure chamber communicating with a master cylinder for generating a brake pressure based on a brake operation amount, an output pressure chamber communicating with a caliper cylinder for operating a wheel brake, the input pressure chamber and the output pressure chamber. An adjusting chamber provided between the adjusting chamber and the output pressure chamber, and a piston provided in the output pressure chamber so as to move back and forth, and a tip end portion of the piston abuts and interlocks to communicate the adjusting chamber with the output pressure chamber. A first valve body, a second valve body that makes the adjustment chamber and the input pressure chamber communicate with each other by abutting and interlocking movement of the first valve body, and both ends of the first valve body and the second valve body Are engaged with each other, and both ends are engaged with the first elastic member for urging the first valve body so as to block the communication between the adjustment chamber and the output pressure chamber, and the second valve body and the input pressure chamber. And a second elastic member that blocks communication between the adjustment chamber and the input pressure chamber, A valve mechanism comprising: an orifice that connects the adjustment chamber and the input pressure chamber; and the second elastic member has a larger elastic force than the first elastic member. 2. The valve mechanism according to claim 1, wherein the orifice is formed inside the second valve body.