JPS6137135B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a master cylinder for two-wheeled vehicles.

Generally, the braking system of a two-wheeled vehicle is separated into a front wheel system and a rear wheel system, and the two are used selectively depending on speed and road surface conditions. Therefore, those with excellent driving skills can make full use of their driving techniques by skillfully using both, but those with less skills, such as beginners, use the rear brakes exclusively to avoid falling due to the front wheels locking. Braking efficiency tends to be used frequently, and braking efficiency cannot be fully demonstrated.

Therefore, in order to increase braking efficiency, there are systems that configure a braking mechanism using a tandem master cylinder for two-system control of the front and rear wheels, and link the rear wheel brake and front wheel brake (for example, No. 49-42383).

However, as shown in the above publication,
If the front and rear wheel system hydraulic pressures are controlled in conjunction, the brakes for both systems will operate at the same time. On the other hand, in order to prevent the front wheels from locking up, it is desirable that the rise in hydraulic pressure for the front brakes be delayed compared to that for the rear brakes.

In addition, it becomes impossible to use the brakes for the front and rear wheels individually, making it impossible to control the vehicle, reducing the function of the brake system by half, and in the case of sudden braking, one brake input becomes
Since it is used in two systems, it is conceivable that this may lead to insufficient braking power.

Therefore, this invention can delay the rise of the hydraulic pressure of the front wheel brake when it is linked with the rear wheel brake, and it is also possible to operate only one of the brakes, reducing the braking force required for sudden braking etc. The purpose is to provide a master cylinder that can be secured.

Hereinafter, the configuration of the present invention will be explained based on the accompanying drawings.

The master cylinder of this invention is divided into two types: a single master cylinder A shown in FIG. 1, and a combination thereof with a normal master cylinder. As shown in FIG. 1, the single master cylinder A has a first piston 2 inserted into the closed end of the cylinder 1, and a second piston 3 inserted into the open end. A first pressure chamber 4 is formed between the first piston 2 and the closed end, and a second pressure chamber 4 is formed between the first piston 2 and the closed end.
A pressure chamber 5 is formed.

An annular groove 6 is provided on the outer periphery of the first piston 2, and this annular groove 6 communicates with a brake oil tank 8 through a small hole 7 provided in the cylinder 1. Second
The pressure chamber 5 communicates with the annular groove 6 through a communication passage 9 provided in the first piston 2 .

A proximity valve 10 for opening and closing the communication passage 9 is provided within the second pressure chamber 5. In the illustrated case, the proximity valve 10 has the following structure.

That is, the cups 11, 11' are provided on the opposing surfaces of the first piston 2 and the second piston 3, respectively, and the coil springs 12 are compressed and fitted between them, thereby fixing the cups 11, 11'. The coil spring 12 is connected to both pistons 2 and 3.
It also has the effect of receding. Each cup 11,
A valve rod 13 freely passes through 11', and a valve 14 is provided at the end of the valve rod 13 on the first piston 2 side, and a stopper 15 is provided at the other end. Further, a packing 15' is attached around the valve 14.

The valve 14 is constantly pushed in the direction of the first piston 2 by a conical coil spring 16 compressed and fitted between the valve 14 and the inner surface of the cup 11.
Since the pressing force of this spring 16 is considerably smaller than the pressing force of the coil spring 12 described above, in a steady state, the stopper 15 of the valve rod 13
is engaged with the cup 11', and the valve 14 is connected to the communication passage 9.
It is stationary near the open end of the.

The above-mentioned proximity valve 10 has a second pressure chamber 5 when the first piston 2 and the second piston 3 approach each other.
The communication passage 9 is closed so that the oil inside does not flow back into the tank 8.

On the other hand, in the annular groove 6 of the first piston 2,
A stopper 17 protruding from the inner wall of the cylinder 1 is fitted. This stopper 17 is connected to the first piston 2
When the first piston 2 is in a steady state, the first piston 2 is unable to move back any further because it is engaged with the peripheral wall of the annular groove 6 near the second pressure chamber 5.
A movable stopper 18 of a stopper mechanism for the purpose of delaying the rise of the hydraulic pressure in the second pressure chamber 5 shown in FIGS. be limited. This configuration will be described later.

In FIG. 1, the aforementioned first pressure chamber 4 is provided with an inlet 19 for brake oil, and the second pressure chamber 5 is provided with an outlet 20. Others, 21 in the figure
indicates a cup seal, and 22 indicates a stop ring of the second piston 3. Further, on the outer surface of the second piston 3, there is a hole 23 for inserting a push rod or the like.
is provided.

By the way, as shown in FIG. 2, the movable stopper 18 mentioned above is provided with a sub cylinder 24 outside the cylinder 1 in a direction perpendicular to the cylinder 1.
A movable stopper 18 provided at the tip of the piston 25 in the sub-cylinder 24 penetrates the wall of the cylinder 1 in a liquid-tight manner and engages with the annular groove 6 of the first piston 2. When the first piston 2 is in a steady state, the movable stopper 18 engages with the peripheral wall of the annular groove 16 near the first pressure chamber 4 and prevents the first piston 2 from moving forward.

One pressure chamber 26 of the sub-cylinder 24 communicates with the second pressure chamber 5 through a passage 27,
Due to the increase in pressure in the second pressure chamber 5, the piston 25
The movable stopper 18 integrated therewith overcomes the pressing force of the spring 28 and retreats, and the first piston 2
It is designed to disengage from the

FIG. 3 shows another movable stopper mechanism. In this case, a sub-cylinder 29 is provided along the cylinder 1, and a cam 31 having a partially tapered surface 30 is slidably inserted into the sub-cylinder 29. This cam 31 is pressed against a piston 33 by a spring 32.
A hole 34 communicating with the annular groove 6 of the first piston 2 is provided in the wall of the cylinder 1 corresponding to the tapered surface 30 of the cam 31, and a ball 35 as a movable stopper is fitted into the hole 34. ing. This ball 35 engages with the peripheral wall of the annular groove 6 closer to the first pressure chamber 4 .

One end of the sub-cylinder 29 communicates with the second pressure chamber 5 of the cylinder 1 through a passage 36, so when the pressure in the second pressure chamber 5 increases, the piston 33 advances the cam 31, causing the ball 35 to move forward. The engagement with the first piston 2 is released by dropping it into the deep part of the tapered surface 30.

FIG. 4 shows another example. In this case, a sub-cylinder 37 is provided on the outer periphery of the cylinder 1, and a stepped annular piston 38 is inserted into the sub-cylinder 37.
A tapered surface 39 is provided on the inner circumference of the piston 38, and the cylinder 1 corresponds to this tapered surface 39.
An annular slit 40 is provided in the wall. A split ring washer 41 as a movable stopper is fitted into the gap between the slit 40 and the tapered surface 39, and this washer 41 is attached to the peripheral wall of the annular groove 6 of the first piston 2 near the first pressure chamber 4. engaged. Furthermore, the annular chamber 42 of the sub-cylinder 37 communicates with the second pressure chamber 5 .

In the master cylinder having the above configuration, when the second piston 3 is stationary, the inlet 19
Since the first piston 2 does not operate when hydraulic pressure is received from the outlet 20, no pressure oil is delivered to the outlet 20.

When the second piston 3 is pressed by a push rod or the like, the first piston 2, which is blocked by the fixed stopper 17, does not operate, and only the second piston 3 compresses the coil spring 12 and moves forward. , the communication path 9 is closed by the valve 14,
Pressure oil is delivered to the outlet 20.

Next, an explanation will be given of the operation when hydraulic pressure is applied to the inlet 19, thereby pressing the first piston 2, and at the same time, the second piston 3 is also pressed by a push rod or the like. In this case, the pressure in the second pressure chamber 5 increases due to the operation of the second piston 3, and the second pressure increases more than the force of the spring 28, etc. that directly or indirectly biases the movable stopper in the projecting direction. When the force in the disengagement direction of the movable stopper from the first piston 2 due to the hydraulic pressure in the chamber increases, the movable stopper moves back and disengages from the first piston 2.
As a result, the first piston 2 operates later than the second piston 3 from the start of control until the spring 28 etc. are compressed, and in the system connected to the first pressure chamber 4, the movement of the second piston 3 Since the volume expansion of the system is delayed, the rise of the hydraulic pressure branched to the brake is accelerated before entering the inlet 19, and on the other hand,
In the system connected to the second pressure chamber 5, the volume reduction is delayed due to the absence of movement of the second piston 3, and the rise of the hydraulic pressure is delayed. Therefore, by connecting the outlet 20 to the front wheel brake, the problem of the front wheel locking when the first and second pistons are interlocked can be eliminated.

5 and 6 show a second embodiment of the present invention in which the above-mentioned master cylinder is combined with a second master cylinder B.
shows the master cylinder. The second master cylinder B has a single piston 60 and a brake oil outlet 61
This is a well-known master cylinder with a

In the case of FIG. 5, the brake lever 50 and the second piston 3 of the first master cylinder A are mechanically connected by the aforementioned push rod or the like, and its outlet 20 is connected to the front wheel brake 51. Entrance 1
9 is connected to the outlet of the second master cylinder B by an oil passage 52, and the second master cylinder A
A pedal 53 is mechanically connected to the inlet. The middle of the oil passage 52 is branched and connected to a rear wheel brake 55 via a pressure reducing valve 54. however,
The pressure reducing valve 54 may be omitted in some cases.

The brake operation when the master cylinders A and B are arranged and connected as shown in FIG. 5 will be explained. First, when only the pedal 53 is depressed, the hydraulic pressure generated in the second master cylinder B operates the rear wheel brake 55 via the pressure reducing valve 54. At this time, the first piston 2 does not operate, so the front wheel brake 51 does not operate.

Also, if only the handle lever 50 is squeezed, the first
Only the second piston 3 of the master cylinder A operates, and only the front wheel brake 51 is operated.

Further, when both the pedal 53 and the handle lever 50 are operated simultaneously, the second master cylinder B operates the rear wheel brake 55. Also, the first
In the master cylinder A, the operation of the first piston 2 is slightly delayed, so the timing at which pressure is applied to the front wheel brake 51 is slightly delayed. The effects of its delayed action are as described above.

FIG. 6 shows a case where the second master cylinder B is connected to the handle lever 50 side, the pedal 53 is connected to the second piston 3 of the first master cylinder A, and the outlet 20 is connected to the rear wheel brake 55 side. . The operation in this case is almost the same as in the case of FIG. 5, so the explanation thereof will be omitted.

This invention broadly includes an invention related to a master cylinder explained based on FIGS. 1 to 4, and an invention related to a kind of tandem type master cylinder explained based on FIGS. 5 and 6.

In both master cylinders, when braking input is applied to the first piston 2 and the second piston 3 at the same time, the pressure increase in the hydraulic system connected to the second pressure chamber is caused by the action of the stopper mechanism having a movable stopper.
Since this is delayed compared to the pressure increase in the hydraulic system connected to the first pressure chamber 1, it is possible to eliminate dangerous front wheel locking in two-wheeled vehicles.

Further, since the first and second pistons 2 and 3 can be operated separately by using a brake handle and a brake pedal, one of which operates a general master cylinder, it is possible to operate the piston with full skill.

Furthermore, if both the first and second pistons are actuated by applying braking input from two separate braking input sections, a larger brake can be achieved in a shorter time than that shown in Utility Model Application No. 49-42383. You can get more power and solve the problem of insufficient braking power.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing the first master cylinder of the present invention, FIG. 2 is a sectional view taken along the - line, and FIGS. 3 and 4 show modified examples of a stopper mechanism with a movable stopper. Cross-sectional view, Figures 5 and 6
The figure is a block diagram showing the second master cylinder of the present invention assembled into a two-wheeled vehicle. 1... Cylinder, 2... First piston, 3...
Second piston, 4... First pressure chamber, 5... Second pressure chamber, 6... Annular groove, 8... Tank, 9... Communication passage, 10... Proximity valve, 17... Fixed stopper, 18 ...Movable stopper, 19...Entrance, 20
... Exit, 27 ... Passage, 35 ... Ball, 36
... Passage, 41 ... Ring washer, 52 ... Oil passage, A ... First master cylinder, B ... Second master cylinder.

Claims (1)

[Claims] 1. A first piston 2 is inserted into the closed end of the cylinder 1 to form a first pressure chamber 4 between the closed end and the first piston 2, and a second pressure chamber 4 is formed between the closed end and the first piston 2. A second pressure chamber 5 is formed between the two pistons 2 and 3 by inserting the piston 3, and a proximity valve 1 opens and closes a communication passage 9 between the chamber and the brake oil tank 8 in the second pressure chamber 5.
a fixed stopper 17 which is provided at 0 and prevents the first piston 2 from retreating from its steady state;
A stopper mechanism is provided on the inner wall of the cylinder 1 for engaging a movable stopper projected into the cylinder 1 by an elastic body and restricting its advancement, and a cylinder for operating the movable stopper in the disengagement direction from the first piston 2. A master cylinder for a two-wheeled vehicle, characterized in that the first pressure chamber 4 is provided with an inlet 19 for braking oil, and the second pressure chamber 5 is provided with an outlet 20. 2 The first piston 2 is inserted into the closed end of the cylinder 1 to form the first pressure chamber 4 between the closed end and the first piston 2, and the second piston 3 is inserted into the open end of the cylinder 1 to form a first pressure chamber 4 between the closed end and the first piston 2. A second pressure chamber 5 is formed between the pistons 2 and 3, and a proximity valve 1 opens and closes a communication passage 19 between the second pressure chamber 5 and the brake oil tank 8.
a fixed stopper 17 which is provided at 0 and prevents the first piston 2 from retreating from its steady state;
A stopper mechanism is provided on the inner wall of the cylinder 1 for engaging a movable stopper projected into the cylinder 1 by an elastic body to limit its advancement, and a cylinder for operating the movable stopper in the disengagement direction from the first piston 2 is provided. A brake oil inlet 19 communicates with the second pressure chamber 5 and is connected to the first pressure chamber 4;
The inlet 19 of the first master cylinder A consists of a combination of a first master cylinder A having an outlet 20 thereon, and a second master cylinder B having a single piston 60 and an outlet 61 for braking oil.
and the outlet 61 of the second master cylinder B is connected to the oil passage 52.
A master cylinder for a two-wheeled vehicle characterized by being connected by.