JPH07317806A - Master cylinder device for liquid pressure clutch - Google Patents

Abstract

PURPOSE:To provide a master cylinder device which can lessen the force to hold an operational member in a certain position wherein the operating force is not influenced by the operating speed of the operational member. CONSTITUTION:When an operational member is held in a position on the way of declutching motion, a free piston 22 works as narrowing the first division 30a because of being energized in the first direction, and an opening at the tip of a piston 26 is in contact with the free piston 22 and is closed, and a one-way valve 24 hinders the clutch liquid from flowing into a reserve tank 18 from the first division 30a. Thereby the pressure of clutch liquid in the first division 30a is heightened, but stopping on the way can be managed with a holding force according to the ratio d/D, where D and (d) represent the diameters of the free piston 22 and piston 26, respectively, and it is possible to hold on the way of clutch motion with a minor force.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention converts a clutch operation input to an operation member such as a clutch lever of a two-wheeled vehicle (including a three-wheeled vehicle and a four-wheeled vehicle) into hydraulic pressure and outputs the converted hydraulic pressure toward the clutch. The present invention relates to a master cylinder device for a hydraulic clutch.

[0002]

2. Description of the Related Art Generally, in a vehicle such as a motorcycle,
The force with which the driver operates the clutch increases in proportion to the size of the engine. Therefore, in large motorcycles, hydraulic clutches, which provide a large operating force by hydraulic pressure (a type of hydraulic pressure), are widely used instead of mechanical clutches that engage and disengage the clutch via wires. There is. This hydraulic clutch is generally provided with a clutch including a plurality of clutch discs and clutch plates that are alternately stacked and a clutch spring that is pressed to connect these members, and the clutch lever is gripped. By generating hydraulic pressure by pressing the clutch spring in the opposite direction via the push rod, the engagement between the tech clutch disc and the clutch plate is released, the clutch is disengaged, and the rotational force of the engine is shut off. ing.

[0003]

However, in the conventional hydraulic clutch of this type, when the gripping force for grasping the clutch lever is loosened and the clutch is gradually connected, the operation of the clutch lever is felt to be heavy, and the fine adjustment of the clutch is required. There was a problem that it became difficult. On the other hand, a hydraulic clutch has already been proposed in JP-A-61-268531. In the hydraulic clutch described in this publication, as shown in FIG. 6, a check valve c and an orifice d are provided midway in an oil passage from a master cylinder a that generates hydraulic pressure by operating a clutch lever to a clutch cylinder b. During the clutch disengagement operation (holding the clutch lever), the hydraulic pressure is supplied to the cylinder b through the released check valve c to quickly disengage the clutch, while the clutch disengagement operation (return the clutch lever). In the case of), the oil passage is throttled by the orifice d so that the clutch returns slowly.

However, even in the above technique, when the clutch is stopped and the clutch is slowly returned, the operating force is heavy, and when the clutch is quickly returned, the operating force is light. Therefore, the operating force changes depending on the speed at which the clutch lever is returned. In addition, there is a problem that the delicate operation of the clutch is difficult because the operating force changes depending on the returning speed. Further, when the clutch is stopped at a certain position in the middle of the stroke such as a half clutch (half clutch) and held at that position, the holding force cannot be reduced.

The present invention has been made in order to solve the above-mentioned conventional problems. The operation force is not affected by the operation speed of the operation member, and the holding force for holding the operation member at a fixed position is provided. An object of the present invention is to provide a master cylinder device for a hydraulic clutch that can be lightened.

[0006]

In order to solve the above-mentioned problems, the invention according to claim 1 converts a clutch operation input to an operating member into a hydraulic pressure of clutch fluid and directs the converted hydraulic pressure to a clutch operating cylinder. In a master cylinder device for a hydraulic clutch that outputs as an output, a reserve tank part that stores the clutch liquid, a cylinder chamber that communicates with the reserve tank part and the clutch operating cylinder, and an outer peripheral diameter that is substantially the same as the cylinder inner peripheral diameter are provided. And a second direction in which the second compartment is expanded by being divided into a first compartment communicating with the reserve tank portion and a second compartment communicating with the clutch actuating cylinder. Between the first piston member biased to the first piston member and the first compartment of the cylinder chamber and the reserve tank portion. And a check valve for allowing the flow of the clutch fluid from the reserve tank to the first section and preventing the reverse, and an operating member having an outer circumference smaller than the cylinder chamber inner circumference. Of the first section through the wall member on the first direction side in the first compartment, and has an opening communicating with the reserve tank portion at the tip, and the tip is opened when the clutch release operation is input. A second piston member that is in contact with a side surface of the first piston member in the first direction and presses the first piston member in a direction opposite to the first direction with the opening closed. It has a structure of a master cylinder device for a hydraulic clutch.

[0007]

According to the first aspect of the present invention, when an operation input for disengaging the clutch is made, the second piston member moves in a direction opposite to the first direction (clutch disengaging operation direction), and the second section of the first section moves. Enter the cylinder chamber through the wall member on one side. The tip of the second piston member contacts the first direction side surface of the first piston member and presses the first piston member in the direction opposite to the first direction with the opening closed. Then, since the first piston member moves in the opposite direction, the second compartment becomes narrower, and the clutch fluid pressure in the second compartment increases, and the clutch fluid is sent to the clutch operating cylinder to reduce the pressure. Increase. This causes the actuating cylinder to disengage the clutch. At the same time, clutch fluid enters the first compartment from the reserve tank through the check valve, and the first piston member smoothly moves in the opposite direction without resistance.

On the other hand, if the operating member is held in the middle of the operation of disengaging the clutch, the first piston member is biased in the first direction, so that the first section is narrowed. To work. Then, the opening at the tip of the second piston member is in contact with the first piston member and the opening is closed, and the check valve prevents the clutch fluid from flowing from the first compartment to the reserve tank portion. To do the first
The pressure of the clutch fluid in the compartment increases. This pressure tends to push back the second piston member, but the outer diameter of the second piston member is smaller than the inner diameter of the cylinder chamber, and the outer diameter of the first piston member is the inner diameter of the cylinder chamber. Since the diameter is almost the same as the diameter, the force of pushing back the second piston member is smaller than the force acting on the first piston member. That is, when the outer diameter of the first piston member is D and the outer diameter of the second piston member is d, (force to be supported by the second piston member) / (force applied by the first piston member) The ratio will be d ² / D ² . d <
Because of D, the clutch can be held at the intermediate position with a small force as compared with directly holding the first piston member.

When the holding of the operating member is stopped and the clutch is engaged, the second piston is moved in the first direction without applying the operating force to the operating member. Then, the clutch fluid in the first section flows from the opening of the second piston to the reserve tank portion, and the clutch fluid pressure in the first section drops. As a result, the first piston member moves in the first direction, and the clutch fluid flows into the second compartment to connect the clutch.

[0010]

Embodiments of the present invention will now be described in detail with reference to the drawings. The embodiment of the present invention is a master cylinder device for a hydraulic clutch provided in a motorcycle. Figure 1
[FIG. 3] is an explanatory diagram of a left grip and a hydraulic path of a steering wheel with which the device is provided in a motorcycle. Figure 2
FIG. 4 is an explanatory diagram of a detailed configuration and operation of the master cylinder device. FIG. 5 is an operation explanatory view of the master cylinder device.

As shown in FIG. 1, the master cylinder device 10 converts the driver's operation (grip and swing the clutch lever 12 together with the grip 14) input to the clutch lever 12 into the hydraulic pressure of the clutch fluid. The converted hydraulic pressure is output to the clutch operating cylinder 16.

As shown in FIGS. 2 to 4, the master cylinder device 10 includes a reserve tank (corresponding to a reserve tank portion) 18, a cylinder chamber 20, a free piston (corresponding to a first piston member) 22. , A one-way valve (corresponding to a check valve) 24 and a piston (corresponding to a second piston) 26 are mainly provided, and in the mounted state of FIG. A tank 18 is formed, and a cylinder chamber 20 having a cylindrical hole shape is provided below the reserve tank 18 forming portion.
Has a main body formed with.

The reserve tank 18 stores the clutch liquid 28, and has a lid member 18a attached to the upper portion thereof and is fastened with a screw 18b so that the clutch liquid 28 does not spill outside. The cylinder chamber 20 communicates with the reserve tank 18 and the clutch operating cylinder 16. The cylinder chamber 20 is covered with a dust boot 20a on the side where the end 12a of the clutch lever 12 is inserted to prevent dust from entering, and on the side communicating with the working cylinder 16 for connecting a pipe. Cylinder chamber 20 in which a thread groove is formed
It communicates with a hole 20b having a smaller diameter.

The free piston 22 has an outer peripheral diameter that is substantially the same as or similar to the inner peripheral diameter of the cylinder chamber 20 (indicated by the symbol D), and is movable back and forth within the cylinder chamber 20. In addition, the free piston 22 is the cylinder chamber 2
A predetermined direction in which 0 is divided into a first section 30a communicating with the reserve tank 18 and a second section 30b communicating with the clutch operating cylinder 16 and the second section 30b is expanded (reference numeral in FIGS. 2 to 4) A is indicated by A: equivalent to the first direction) and is urged by a spring 32 having a shape along the conical side surface. The spring 32 has a large diameter side in contact with the side of the small diameter hole 20b of the cylinder chamber 20, and a small diameter side in contact with the free piston 22 via the seal lip 34. Urge towards.

The one-way valve 24 is interposed between the first compartment 30a of the cylinder chamber 20 and the reserve tank 18 to allow the flow of the clutch fluid 28 from the reserve tank 18 to the first compartment 30a. It allows and prevents the opposite. In the embodiment, in the master cylinder body, the one-way valve 24 includes a valve boss 24a that cylindrically protrudes from the upper portion of the cylinder chamber 20 into the reserve tank 18, and the reserve tank 18 and the cylinder chamber 20 (formed in the valve boss 24a). First
Communication hole 24b which is a hole having a step 24b1 having a large diameter at the center and a small diameter at the upper and lower ends and a center of the communication hole 24b. It has a ball 24c which is a valve body inserted into the inside of the section, and a spring body 24d which biases the ball 24c upward. The spring body 24d urges the ball 24c against the lower surface of the upper step 24b1 in the communication hole 24b to close the communication hole 24b.
When the pressure in the cylinder chamber 20 (first section 30a) reaches a predetermined negative pressure (pressure overcoming the elastic force of the spring body 24d), the clutch liquid 28 in the reserve tank 18 is opened to the cylinder chamber 20. On the other hand, the pressure is closed when the pressure in the cylinder chamber (first section 30a) becomes positive pressure or less than the predetermined negative pressure.

The piston 26 is formed to have an outer peripheral diameter d smaller than the inner peripheral diameter D of the cylinder chamber 30, and the partition wall (wall member) on the predetermined direction A side of the first section 30a by an operation input of the clutch lever 12. Corresponding to the end 2) and can be retracted into the cylinder chamber 20 through the tip 2
6a has an opening 38 communicating with the reserve tank 18, and when an operation input for disengaging the clutch is made, the tip 26a contacts the side surface 22a of the free piston 22 in the predetermined direction A and the free piston 22 is closed. Is pressed in the direction opposite to the first direction A (clutch disengagement operation direction F).

The piston 26 is concentrically arranged in a bore 40 extending in the first direction A beyond the partition wall 36 in the same diameter as the cylinder chamber 30 in the master cylinder body, and moves forward and backward. Also, the piston 26 has two
It has a substantially columnar shape with two brim portions 26b and 26c, and has a second opening 42 in the bore 40 and the opening 4
2 and the hollow hole 4 communicating with the opening 38 of the tip 26a.
4 are formed. An annular recess 26d is formed between the flange portion 26b and the flange portion 26c, and a seal lip 46 that keeps the air tightness of the bore 40 by contacting the inner peripheral surface of the bore 40 with the outside is formed in the recess 26d. It is fitted. Further, a second spring 48 that urges the piston 26 in the first direction is interposed between the flange portion 26c on the partition wall 36 side and the partition wall 36. Further, the partition wall 36 has a substantially cylindrical shape and is closely fitted into the bore 40. An annular stopper 50 fitted on the inner peripheral surface of the bore 40 prevents the partition wall 36 from moving in the axial direction of the bore 40. Regulated. The partition wall 36 has a piston 2 at the center of its axis.
6, a passage hole 36a into which 6 is inserted so as to move forward and backward, and a passage hole 3
O interposed between the inner peripheral surface of 6a and the outer peripheral surface of piston 26
And a ring 52.

A communication hole 54 is formed from the bore 40 to the reserve tank 18, and the communication hole 54 allows the piston 26 to open from the first section 38 to the opening 38.
The clutch liquid that has passed through the hollow hole 44 and the second opening 42 and is discharged into the bore 40 is returned to the reserve tank 18. In addition, a communication hole 58 is formed in the upper portion of the cylinder chamber 30 to communicate the second compartment 30b with the reservoir tank 18 when the free piston 22 reaches the end in the predetermined direction A most.

A mortar-shaped recess 26e is formed at the end A of the piston 26 in the predetermined direction.
The second end 12 a is in contact with the piston 26 and pushes the piston 26 in the operating direction F by operating the clutch lever 12.

Next, the operation of the embodiment will be described. When an operation input for disengaging the clutch is made, the clutch lever 12 is grasped and the clutch lever end 12a is moved to the bore 40 as shown in FIG.
Insert it inside. Since the lever end 12a pushes the piston 26, the piston 26 enters the cylinder chamber (first section 30a) through the partition wall 36 in the clutch disengagement operation direction (reverse direction of the first direction) F, and the piston 2
The distal end 26a of 6 contacts the side surface of the free piston 22 in the first direction and presses the free piston 22 in the operating direction F with the opening 38 closed.

Then, since the free piston 22 moves in the operating direction F, the second compartment 30b becomes narrower, the pressure of the clutch fluid 28 in the second compartment 30b increases, and the clutch fluid 28 is used for clutch operation. It is sent to the cylinder 16 to increase its pressure. As a result, the operating cylinder 16 operates to disengage the clutch. At the same time, the clutch fluid 28 enters the first compartment 30a from the reserve tank 18 through the one-way valve 24, and the free piston 22 smoothly moves in the operation direction F without resistance.

On the other hand, as shown in FIG. 3, when the clutch lever 12 is held in the middle of the clutch disengagement operation, the free piston 22 is urged in the first direction or the clutch is actuated. Cylinder 1
The reaction force from 6 acts to narrow the first section 30a. Then, the opening 38 at the tip of the piston 26 is in contact with the free piston 22 and the opening 38 is closed, and the one-way valve 24 prevents the clutch fluid 28 from flowing into the reserve tank 18 from the first compartment 30a. Therefore, the clutch fluid 28 in the first compartment 30a
Pressure increases. The piston 26 tends to be pushed back by this pressure, but the outer diameter d of the piston 26 is smaller than the inner diameter of the cylinder chamber 20, and the outer diameter D of the free piston 22 is equal to the inner diameter of the cylinder chamber 20. Since the diameters are almost the same, the force of pushing back the piston 26 is smaller than the force acting on the free piston 22. The outer diameter of the free piston 22 is D, and the piston 26
Assuming that the outer peripheral diameter of d is d, the ratio of (force to be supported by piston 26) / (force applied by free piston 22) is d ² /
It becomes D ² . Since d <D, the clutch can be held at the intermediate position with a small force.

As shown in FIG. 4, when holding the clutch lever 12 is stopped and the clutch is engaged,
If no operating force is applied to the clutch lever 12, the elastic force of the second spring 48 moves the piston 26 in the first direction. Then, the clutch fluid 28 in the first section 30 a is transferred from the opening 38 of the free piston 22 to the hollow hole 44,
As it flows into the reserve tank 18 through the second opening 42 and further within the bore 40, the pressure in the compartment 30a first decreases. This causes the free piston 22 to move to the spring 32.
Is moved in the predetermined direction A by the elastic force of, and the clutch liquid 28 flows into the second compartment 30 to connect the clutch.

When the free piston 22 has finished moving in the predetermined direction A, the second section 30b is connected to the inside of the reservoir tank 18 through the communication hole 58. As a result, the clutch liquid is replenished so that the clutch has sufficient clutch liquid. Here, an example of the operating force of the clutch lever is shown in FIG. When the clutch lever 12 is grasped to disengage the clutch, the lever load increases in accordance with the lever stroke as indicated by reference numeral s1 in FIG. When the clutch lever 12 is held by stopping the grip at the middle (broken line) or the end (solid line) of the lever stroke, the lever load has the relationship indicated by reference numeral s2. The lever load s2 is smaller than the lever load s1, and the reduced amount allows the operating force to be felt lightly. The ratio of the loads s1 and s2 becomes equal to the ratio of the axial sectional areas of the pistons 22 and 26 (a / b =
^{s2 / s1 = d 2 / D} 2).

In the above embodiment, the case where the present invention is applied to the clutch device of a motorcycle is illustrated, but the scope of the present invention is not limited to this, and any device that requires a clutch device can be used in a motorcycle, The present invention can be implemented by any device that requires a clutch for interrupting the output of a prime mover such as a three-wheeled vehicle, a four-wheeled vehicle, or the like.

[0026]

As described above, according to the present invention, the operating force is not affected by the operating speed of the operating member, and the holding force for holding the operating member at a fixed position can be reduced. Therefore, the operating force of the operating member is lightened at a constant rate and is not affected by the returning speed. Further, since the present invention can be constructed only by changing the structure of the master cylinder, no other force such as electricity or negative pressure is required. Therefore, the configuration is simple.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a periphery of a left grip of a handle and a path of clutch fluid in a motorcycle equipped with a master cylinder device for a hydraulic clutch in a motorcycle according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram of a detailed configuration and operation of the master cylinder device of the embodiment.

FIG. 3 is an explanatory diagram of a detailed configuration and operation of the master cylinder device of the embodiment.

FIG. 4 is an explanatory diagram of a detailed configuration and operation of the master cylinder device of the embodiment.

FIG. 5 is an explanatory view of an operation example of the master cylinder device of the present invention.

FIG. 6 is an explanatory diagram of an example of a conventional master cylinder device.

[Explanation of symbols]

 10 Master Cylinder Device 12 Clutch Lever 12a Clutch Lever End 16 Actuating Cylinder 18 Reserve Tank 20 Cylinder Chamber 22 Free Piston (Equivalent to First Piston Member) 22a Free Piston First Direction Side 24 One Way Valve (Check Valve) 26 piston (corresponding to the second piston member) 26a tip 28 clutch fluid 30a first section 30b second section 32 spring 36 partition wall 36 38 opening 40 bore 42 second opening 44 hollow hole

Claims (1)

[Claims] 1. A reserve tank for storing clutch fluid in a master clutch device for a hydraulic clutch, which converts a clutch operation input to an operating member into a hydraulic pressure of clutch fluid and outputs the converted hydraulic pressure toward a clutch operating cylinder. Portion, a cylinder chamber communicating with the reserve tank portion and the clutch operating cylinder, and having an outer peripheral diameter substantially similar to the inner peripheral diameter of the cylinder chamber, capable of advancing and retracting in the cylinder chamber, and the reserve tank portion in the cylinder chamber. A first section that is urged in a first direction to expand the second section by dividing the second section into a first section that communicates with the first cylinder and a second section that communicates with the clutch operating cylinder; No. 1 from the reserve tank part is interposed between the first compartment and the reserve tank part.
Check valve for allowing the flow of the clutch fluid to the compartment and blocking the reverse, and a first valve of the first compartment having an outer circumference of a diameter smaller than the inner diameter of the cylinder chamber and an operation input of the operating member. Direction wall of the first piston member, which is freely retractable in the cylinder chamber, has an opening leading to the reserve tank portion at the tip, and the tip is the first side surface of the first piston member when a clutch disengagement operation is input. And a second piston member that presses the first piston member in a direction opposite to the first direction in a state where the opening is closed in contact with the master cylinder device for a hydraulic clutch.