JP2627452B2 - Modulator for anti-lock brake - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION A. Object of the Invention (1) Field of the Invention The present invention relates to a modulator for controlling a brake oil pressure transmitted from a master cylinder to a wheel brake in an antilock brake device for a vehicle.

(2) Prior Art Normally, a modulator of an anti-lock brake device for a vehicle is provided with a cut valve which controls communication and shutoff between an input hydraulic chamber communicating with a master cylinder and an output hydraulic chamber communicating with wheel brakes, and the output valve. An expander piston is provided in the hydraulic chamber and closes the cut valve during the antilock brake control device and increases the volume of the output hydraulic chamber to reduce the brake hydraulic pressure.

Conventionally, in such an anti-lock brake device, a control hydraulic pressure generated by a hydraulic pump is supplied to a modulator via a solenoid valve, and the expander piston is operated by the hydraulic pressure.

(3) Problems to be Solved by the Invention However, in the above-described conventional anti-lock brake device, since the expander piston is operated by controlling the control oil pressure supplied to the modulator by the solenoid valve, a hydraulic circuit for that is necessary. As a result, the number of parts increased, and special techniques and man-hours were required not only for productivity but also for maintenance and inspection.

The present invention has been made in view of the above circumstances, and has as its object to provide a modulator for an anti-lock brake which does not require a control hydraulic circuit having a large number of parts, and is excellent in point maintenance and response. .

B. Configuration of the Invention (1) Means for Solving the Problems In order to achieve the above object, the present invention provides an input hydraulic chamber communicating with a master cylinder, an output hydraulic chamber communicating with a wheel brake, and both hydraulic pressure chambers. A cut valve that communicates and shuts off between the chambers; and a cut valve that is disposed to face the output hydraulic chamber and opens the cut valve during normal braking, and closes the cut valve during antilock control operation, and outputs hydraulic pressure. In a modulator for an anti-lock plate having an expander piston for increasing the volume of a chamber, a drive shaft having an eccentric portion abutting on the back of the expander piston, and the expander piston is moved by rotating the drive shaft. An electric motor and a regulating means for rotating the drive shaft within a predetermined range are provided. And it said to be bound the scan panda piston.

(2) Operation According to the above-described feature of the present invention, during normal braking, the eccentric portion provided on the drive shaft is located at the top dead center and restrains the expander piston, so that the cut valve is forcibly opened. The master cylinder communicates with the wheel brake. At this time, the brake hydraulic pressure generated in the master cylinder is transmitted to the eccentric portion via the expander piston, but since the eccentric portion is located at the top dead center, no load acts on the electric motor. .

At the time of the antilock control operation, the drive shaft is rotated by the electric motor, and the eccentric portion moves toward the bottom dead center. Thereby, the expander piston moves and the cut valve closes, and at the same time, the volume of the output hydraulic chamber increases and the brake hydraulic pressure decreases, thereby preventing the wheels from entering the locked state.

In addition, since the rotation of the drive shaft is restricted within a predetermined range by the restricting means, the expander piston is repeatedly reciprocated in a short cycle, and the output hydraulic pressure does not fluctuate finely, thereby enabling smooth antilock control.

(3) Example Hereinafter, an example of the present invention will be described with reference to the drawings.

1 to 7 show a first embodiment of the present invention.
1 is an overall side view of a motorcycle equipped with the modulator, FIG. 2 is an enlarged view of a part II in FIG. 1, FIG. 3 is a sectional view taken along the line III-III in FIG. 2, and FIG. FIG. 3 is a sectional view taken along the line IV-IV of FIG. 3 showing a longitudinal section, and FIG.
6 is a sectional view taken along line VI-VI of FIG. 4, and FIG. 7 is a sectional view taken along line VII-VII of FIG.

As shown in FIG. 1, the front wheel brake of the motorcycle V includes a master cylinder Cm driven by a brake lever 2 provided on a steering wheel 1 and a caliper cylinder Cc for braking the front wheel Wf. The cylinders Cc are connected to each other via a modulator M mounted on the front of the front fork 3. On the other hand, the rear wheel brake includes a master cylinder Cm driven by a brake pedal 4 provided at a lower rear portion of a vehicle body and a caliper cylinder Cc for braking the rear wheel Wr, and a modulator disposed between the master cylinder Cm and the caliper cylinder Cc. M is provided. The modulators M of the rear wheel Wr and the front wheel Wf have the same structure, and the modulator M on the front wheel Wf side will be described below.

As shown in FIGS. 2 and 3, a top pipe 6 and a bottom bridge 7 for supporting the left and right front forks 3 are supported on the head pipe 5 of the motorcycle V. In the upper front space of the bottom bridge 7, a substantially cylindrical modulator M is disposed in a horizontal posture such that both ends of the modulator M do not protrude outward from the left and right front forks 3, and the operating sound to the handle 1 is provided on the outer periphery thereof. The mounting plate 8 wound around an elastic material for preventing transmission of vibration is attached to the bottom bridge 7 by bolts 9. By mounting the modulator M as described above, the modulator M is protected by being surrounded by the left and right front forks 3 and the bottom bridge 7, and is prevented from interfering with tires and fenders during steering. Further, since the modulator M is located near the head pipe 5 serving as the center of rotation, not only the twisting of the pipe during steering is minimized, but also the modulator M is connected to the master cylinder Cm.
And the caliper cylinder Cc at a substantially intermediate portion, the pipe length can be reduced.

As shown in FIGS. 4 and 5, the modulator M is composed of a main body storage section 10 and a driving DC motor 12 connected to one end of the main body storage section by bolts 11. An input hydraulic chamber 16 connected to a master cylinder Cm via an input port 15 is provided in a valve storage section 14 connected to the side of the main body storage section 10 with bolts 13.
And a cut valve 17 is housed inside. The cut valve 17 includes a shaft portion 17a that is loosely fitted in a communication hole 14a formed in an end wall of the valve housing portion 14, and a valve body 17b that can abut a valve seat 14b formed in the end wall. The valve body 17b is urged in the valve closing direction by a spring 19 contracted between the valve body 17b and the spring seat 18. Main unit storage 10
Is formed with a cylindrical output hydraulic chamber 21 in which an expander piston 20 is slidably fitted. The output hydraulic chamber 21 communicates with a caliper cylinder Cc through an output port 22 and has the communication hole. It communicates with the input hydraulic chamber 16 via 14a.

A drive shaft 25 is rotatably supported in a space formed inside the main body storage section 10 via a pair of ball bearings 23 and 24. The drive shaft 25 includes a first drive shaft 26 having an internal gear 26a and an eccentric hole 26b, and an eccentric pin 27a fitted into the eccentric hole 26b.
A cam bearing 28 is mounted on the eccentric pin 27a as an eccentric portion that comes into contact with the back of the expander piston 20. And the cam bearing 28 attached to the drive shaft 25
Is at the top dead center, the top surface of the expander piston 20 pushes up the shaft portion 17a of the cut valve 17, and the cut valve 1
When the valve 7 is opened, the master cylinder Cm and the caliper cylinder Cc communicate with each other.

6, the pinion 29a formed at the tip of the output shaft 29 of the DC motor 12 meshes with the internal gear 26a formed on the first drive shaft 26, and
Is driven to rotate. By using the internal gear 26a in this manner, the drive shaft 25 and the DC motor 12 are disposed substantially coaxially,
The outer diameter of the modulator M can be minimized. A stopper piece 26c is projected outside the internal gear 26a, and the stopper piece 26c is brought into contact with regulating surfaces 10a and 10b formed on the inner surface of the main body storage section 10, thereby rotating the drive shaft 25. The angle is restricted to a range of about 180 °. The stopper piece 26c and the regulating surfaces 10a and 10b constitute the regulating means of the present invention.

7, a return spring is provided between the end of the second drive shaft 27 and the main body storage section 10.
A spring 30 urges the drive shaft 25 in a direction toward the top dead center of the cam bearing 28, that is, in a direction in which the cut valve 17 opens.

A potentiometer 31 is mounted on an end of the main body housing 10 opposite to the DC motor 12, and an input shaft 31a is connected to an end of the second drive shaft 27 by a pin 32 and rotates in phase. And an electronic control unit consisting of a microcomputer
The signal from the wheel speed sensor 34 and the feedback signal from the potentiometer 31 are input to 33 and subjected to arithmetic processing, and the drive of the DC motor 12 is controlled based on the result.

Next, the operation of the embodiment of the present invention having the above-described configuration will be described.

At the time of normal braking, the resilient force of the return spring 30 causes the stopper piece 26c of the drive shaft 25 to abut on the regulating surface 10a formed on the inner surface of the main body storage section 10, and the cam bearing supported by the eccentric pin 27a of the drive shaft 25 Numeral 28 is held at the top dead center and pushes up the expander piston 20. As a result, the cut valve 17 is forcibly opened against the spring 19, and the brake hydraulic pressure generated in the master cylinder Cm is applied to the input port 15, the input hydraulic chamber 16, the communication hole 14a, the output hydraulic chamber 21, and the output port. Caliper cylinder Cc through 22
Is transmitted to At this time, the brake oil pressure in the output oil pressure chamber 21 acts to push down the expander piston 20, but since the cam bearing 28 in contact with the back of the expander piston 20 is located at the top dead center, the drive shaft 25 No rotational torque is generated by the brake hydraulic pressure. As a result, an unnecessary load is prevented from being applied to the DC motor 12 connected to the drive shaft 25.

When the wheel speed sensor 34 detects that the front wheel Wf is about to enter the locked state, the DC motor 12 is driven by the electronic control unit 33, and the rotation is performed by the pinion 29a.
And transmitted to the drive shaft 25 via the internal gear 26a. When the drive shaft 25 starts rotating and the cam bearing 28 moves from the top dead center, the brake oil pressure acting on the expander piston 20 acts to be added to the torque of the DC motor 12, so that the expander piston 20 To quickly descend. As a result, the cut valve 17 separated from the expander piston 20 is closed by the resilience of the spring 19, and the volume of the output hydraulic chamber 21 increases to reduce the brake hydraulic pressure transmitted to the caliper cylinder Cc.

When the front wheel Wf is prevented from entering the locked state, the power supply to the DC motor 12 is stopped, the drive shaft 25 returns to the original position by the elastic force of the return spring 30, and the brake hydraulic pressure increases again. In this way, starting and starting the DC motor 12
The brake oil pressure is controlled by repeating the stop, and the front wheel Wf is prevented from entering the locked state. At this time, the rotational position of the drive shaft 25 detected by the potentiometer 31 corresponds to the amount of movement of the expander piston 20, that is, the magnitude of the brake oil pressure transmitted to the caliper cylinder Cc. , A closed-loop control yarn is formed, and more precise antilock control becomes possible. For example, the DC motor 12 is moved in a direction to assist the elasticity of the return spring 30.
It is also possible to take full advantage of the closed loop configuration by driving or braking in the direction of deenergization.

FIGS. 8 and 9 show a second embodiment of the present invention. FIG. 8 is a circuit diagram of an antilock brake device using the modulator, and FIG. 9 is a longitudinal sectional view of the modulator.

As shown in FIG. 8, in this embodiment, the rear wheel Wr has one caliper cylinder Cc, the front wheel Wr has two caliper cylinders Cc, and the modulator M on the rear wheel Wr side is the same as the previous embodiment. However, the modulator M 'on the front wheel Wf side is of a tandem type. The master cylinder Cm operated by the brake pedal 4 is connected to the modulator M on the rear wheel Wr side via a pressure control valve 35, and the master cylinder Cm operated by the brake pedal 4 is connected to the modulator M 'on the front wheel Wf side. A master cylinder Cm that is operated by the brake lever 2 is connected while being connected via the pressure control valve 35.

As shown in FIG. 9, a tandem-type modulator M '
Has a pair of input ports 15 and an output port 22 to correspond to a pair of caliper cylinders Cc mounted on the front wheel Wf. A pair of a cut valve 17 and an expander piston 20 are provided between the input port 15 and the output port 22 to control the brake oil pressure, and a pair of cam bearings 28 contacting each expander piston 20 are provided. Is also provided on the extended eccentric pin 27a of the drive shaft 25.

According to the modulator M 'of this embodiment, the same operation and effect as those of the modulator M of the previous embodiment can be obtained. Further, the master cylinder Cm operated by the brake lever 2 and the master cylinder operated by the brake pedal 4 can be obtained. If one of the cylinders Cm fails, the front wheel
The braking force of Wf is secured.

As described above, the embodiments of the present invention have been described in detail. However, the present invention is not limited to the embodiments, and various small design changes may be made without departing from the present invention described in the claims. It is possible to do.

For example, it is possible to use another electric motor such as an AC motor or a step motor in place of the DC motor. Further, another appropriate encoder can be used instead of the potentiometer 31.

C. Effects of the Invention As described above, according to the present invention, since the modulator is driven by the electric motor, the control hydraulic system including the hydraulic pump and the solenoid valve required by the conventional hydraulic drive modulator can be omitted. As a result, the size of the apparatus can be reduced and the number of parts can be reduced. In addition, since the eccentric portion provided on the drive shaft during normal braking restrains the expander piston at the top dead center, unnecessary load is prevented from being applied to the electric motor by the brake hydraulic pressure. In addition, when the drive shaft starts rotating during the anti-lock control operation, the brake oil pressure acts in a direction to assist the rotation of the drive shaft, so that the higher the brake oil pressure, the quicker the pressure reduction response characteristic can be obtained. . Further, since the regulating means regulates the continuous rotation of the drive shaft in one direction, the expander piston does not reciprocate repeatedly in a short cycle, and the output oil pressure does not fluctuate finely, and smooth antilock control can be performed. .

[Brief description of the drawings]

1 to 7 show a first embodiment of the present invention. FIG. 1 is an overall side view of a motorcycle equipped with the modulator, FIG. 2 is an enlarged view of part II of FIG. FIG. 3 is a diagram of FIG.
FIG. 4 is a sectional view taken along the line IV-IV of FIG. 3, FIG. 4 is a sectional view taken along the line VV of FIG. 4, and FIG. 6 is a sectional view of FIG. 7 is a sectional view taken along the line VI-VI of FIG. 7, FIG. 7 is a sectional view taken along the line VII-VII of FIG. 4, and FIGS. 8 and 9 show a second embodiment of the present invention. FIG. 9 is a circuit diagram of the antilock brake device used, and FIG. 9 is a longitudinal sectional view of the modulator. 10a: regulating surface (regulating means), 10b: regulating surface (regulating means), 12: DC motor (electric motor), 16: input hydraulic chamber, 17: cut valve, 20: expander piston, 21 ... output hydraulic chamber, 25 ... drive shaft, 26c ... stopper piece (restriction means), 28 ... cam bearing (eccentric part), Cm ... master cylinder

Claims (1)

(57) [Claims] An input hydraulic chamber (16) communicating with a master cylinder (Cm) and an output hydraulic chamber (21) communicating with a wheel brake.
A cut valve (17) for communicating and shutting off between the two hydraulic chambers (16, 21); and a cut valve (17) arranged to face the output hydraulic chamber (21) during normal braking. Open the cut valve (1
7) A modulator for an anti-lock brake including an expander piston (20) for closing the valve and increasing the volume of the output hydraulic chamber, wherein an eccentric part (28) abutting on the back surface of the expander piston (20) is provided. A drive shaft (25), an electric motor (12) for rotating the drive shaft (25) to move the expander piston (20), and a restricting means for rotating the drive shaft (25) within a predetermined range ( 26c, 10a, 10b), and the eccentric part (28) is located at the top dead center during normal braking to restrain the expander piston (20).