JP3754790B2 - Hydraulic master cylinder device for bar handle vehicle - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a bar handle vehicle such as a motorcycle, a three-wheeled vehicle, or a three- or four-wheeled buggy equipped with a steering handlebar at the front of the vehicle body, and is generated by a combination of a hydraulic master cylinder and an operation lever. The present invention relates to a hydraulic master cylinder device for a bar handle vehicle that operates a brake or a clutch with hydraulic pressure.
[0002]
[Prior art]
Examples of hydraulic master cylinder devices that actuate brakes and clutches for bar handle vehicles with hydraulic pressure include those disclosed in Japanese Utility Model Publication No. 4-34157 and Japanese Patent Application Laid-Open No. 8-150980.
These hydraulic master cylinder devices are provided in a cylinder body of a hydraulic master cylinder attached to a handlebar with a bottomed cylinder hole opened to the side of the vehicle body or in front of the vehicle body, and a master piston is provided in the cylinder hole. A push rod is formed between the operating arm of the operating lever and the master piston by inserting and defining a hydraulic chamber at the bottom of the cylinder hole, pivoting the operating lever on a lever mounting portion extending to the cylinder body. The master piston is pushed toward the bottom of the cylinder hole by the rotation of the operation lever, and the hydraulic fluid pressurized in the hydraulic chamber is supplied to the brake and clutch. It has become.
[0003]
The operating point at which the operating arm of the operating lever pushes the push rod is a fixed distance from the pivot point of the operating lever, and the length L1 from the supporting shaft of the operating lever to the grip operating part (power point) is also the same as the supporting point. The lever ratio of the ratio L1 / L2 of the length L2 from the shaft to the working point where the working arm pushes the push rod is always constant, and the stroke amount of the master piston pushed by the push rod is as shown in FIG. As indicated by the broken line, the operating lever increases in direct proportion to the amount of rotation of the operating lever.
[0004]
[Problems to be solved by the invention]
In such a configuration, since the stroke amount of the master piston is constant with respect to the rotation amount of the operation lever, the caliper piston at the time of releasing the brake is moved backward by a predetermined amount due to the disc rotor swing or the centrifugal force at the cornering travel. When the so-called knockback is returned to the position above and the braking gap between the disc rotor and the friction pad expands beyond a predetermined level, it takes time for the caliper piston of the next braking to fill the braking gap. This will cause a delay in operation.
[0005]
In addition, when the mixed air in the previous hydraulic system is discharged from the hydraulic chamber to the brake or clutch side, there is a problem in that the operation lever grip operation must be repeated many times. Further, the push rod between the working arm and the master piston is gradually tilted as the operating lever is grasped, and the contact point between the working arm and the master piston is disengaged from the cylinder central axis of the hydraulic master cylinder, so that the master There were problems such as the piston being twisted or the master piston being subjected to an unbalanced load, resulting in a decrease in operating force.
[0006]
Therefore, the present invention provides a hydraulic master cylinder device for a bar handle vehicle that is excellent in the start-up of the initial operation and the air bleedability, effectively prevents the master piston from being twisted, and can generate a high output in a normal use region. The purpose is to provide.
[0007]
[Means for Solving the Problems]
According to the present invention, in accordance with the above-described object, a master piston is inserted into a cylinder hole of a hydraulic master cylinder, a hydraulic chamber is defined at the bottom of the cylinder hole, and an operation lever is pivoted at a lever mounting portion of the hydraulic master cylinder. A push rod is interposed between the operating arm of the operation lever and the master piston, and the master piston is pushed toward the bottom of the cylinder hole by the rotation of the operation lever. In the hydraulic master cylinder device for a bar handle vehicle that boosts the hydraulic fluid in the pressure chamber, the push rod is arranged on the cylinder central axis of the hydraulic master cylinder, and a contact point between the push rod and the working arm is set. An operating point A of the operating lever is provided, a connecting arm is extended from the operating lever to the opposite side of the operating point A sandwiching the lever mounting portion, and the connecting arm and one end of the connecting rod are connected to the support shaft B. The other end of the connecting rod and the lever mounting portion are pivotally supported by a support shaft C, and the action point A and the support shaft B are disposed at opposite positions equidistant from the support shaft C. It is characterized by that.
[0008]
When the operation lever is gripped and operated from the above-described configuration, the connecting rod rotates about the support shaft C, the support shaft B moves on an arc centered on the support shaft C, and the operation lever rotates around the support shaft C. Furthermore, the operating point A is pushed on the cylinder center axis toward the bottom of the cylinder hole, and the entire push rod is pushed on the cylinder center axis toward the bottom of the cylinder hole. To move the master piston toward the bottom of the cylinder hole.
[0009]
Of the above-described operations, the length L1 from the support shaft C (fulcrum) to the gripping operation part (power point) of the operation lever and the length L2 from the support shaft C (support point) to the action point A are divided. The lever ratio of the control lever of the alignment L1 / L2 changes with a quadratic curve.
[0010]
Of these, in the normal use range E from the start of the operation lever grip operation until the predetermined hydraulic pressure is generated in the hydraulic chamber, L1 / L2 has a large lever ratio that draws a gentle arc that is close to direct proportionality, A high hydraulic pressure is generated in the hydraulic chamber with a small gripping operation (rotation angle).
[0011]
Further, when the operating lever is greatly gripped beyond the normal use range E, the action point A moves on the cylinder center axis toward the bottom of the cylinder hole and moves away from the support shaft C (support point). As the length L2 between C (fulcrum) and action point A gradually increases and the L1 / L2 lever ratio decreases, the stroke of the master piston increases in inverse proportion.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment in which the present invention is applied to a front disc brake of a bar handle vehicle will be described with reference to FIGS. In describing the present embodiment, FIG. 4 used in the prior art is appropriately taken into account.
[0013]
The hydraulic master cylinder device 1 includes a hydraulic master cylinder 4 attached to a handlebar 2 using a bracket 3, a brake lever 5 attached to the hydraulic master cylinder 4, the brake lever 5 and the hydraulic pressure. It has a push rod 6 and a connecting rod 7 interposed between the master cylinder 4.
[0014]
The hydraulic master cylinder 4 accommodates a master piston 10 in a bottomed cylinder hole 9 provided in the cylinder body 8 so as to open toward the front of the vehicle body in a fluid-tight and movable manner. A vertical center valve type in which a valve stem 12 is disposed in a stem hole 11 drilled on L3. A hydraulic chamber 13 is defined between the master piston 10 and the bottom of the cylinder hole 9, A return spring 14 is contracted in the hydraulic chamber 13, and an output port 15 communicating with the front disc brake is formed in the side wall of the hydraulic chamber 13.
[0015]
The intermediate shaft portion 10a of the master piston 10 is provided with a guide groove 10b penetrating in the radial direction over substantially the entire length, and an oil supply chamber 16 is defined between the intermediate shaft portion 10a and the cylinder hole 9. The oil supply chamber 16 communicates with the hydraulic chamber 13 through the guide groove 10 b and the stem hole 11. A stopper pin 17 is inserted into the guide groove 10b and the oil supply chamber 16 so as to cross the cylinder hole 9 in the radial direction. The master piston 10 determines the stroke amount in the cylinder hole bottom direction by the gripping operation of the brake lever 5 as a stopper pin. 17 and the end wall of the guide groove 10b are regulated (FIG. 2), and the retraction limit biased toward the opening of the cylinder hole 9 by the elastic force of the return spring 14 is a stopper pin. It is regulated by contact with 17 (FIG. 1).
[0016]
The valve stem 12 is formed to be slightly longer than the stem hole 11, and a large-diameter head 12 a that protrudes into the hydraulic pressure chamber 13 is covered with a bowl-shaped retainer 18, and between the retainer 18 and the head of the valve stem 12. A valve spring 19 is contracted between them. The valve stem 12 is always urged toward the opening of the cylinder hole 9 by the elastic force of the valve spring 19, and when the master piston 10 is in the retracted limit position of FIG. Since the valve stem 12 is pushed back toward the hydraulic pressure chamber against the elastic force of the valve spring 19, the head 12 a of the valve stem 12 is separated from the stem hole 11, and the hydraulic pressure chamber 13 and the oil supply chamber 16 are separated. And communicate.
[0017]
When the master piston 10 strokes the cylinder hole 9 in the bottom direction, the master piston 10 comes into contact with the head portion 12a of the valve stem 12, and the valve stem 12 is interlocked in the bottom direction of the cylinder hole 9 to The portion 12a closes the stem hole 11, and the communication between the hydraulic chamber 13 and the oil supply chamber 16 is blocked.
[0018]
The push rod 6 is elastically supported by an elastic cylindrical guide member 20 engaged with the opening of the cylinder hole 9, and a large-diameter sliding portion 6 a formed integrally with the inner end of the master piston 10 in the cylinder hole 9. The rear end is housed in the guide member 20 and is prevented from coming off, and the base end is pivotally supported by the support arm 5a of the brake lever 5 on the support shaft A, and is entirely disposed on the cylinder center axis L3. Yes.
[0019]
The brake lever 5 includes the above-described working arm 5 a connected to the push rod 6, a grip operation portion 5 b disposed along the front of the accelerator grip 21 from the working arm 5 a, and the cylinder body 8 to the support shaft. A pair of upper and lower lever mounting portions 8a, 8a extending toward the vehicle body center side of A is extended around the vehicle body front side, and the support shaft A is sandwiched between the extension portion 5c and the lever mounting portions 8a, 8a. It has bifurcated connecting arms 5d and 5d extending to the facing position. The connecting rod 7 is formed in a long plate shape, and one end and the other end are inserted between the connecting arms 5d, 5d of the brake lever 5 and the lever mounting portions 8a, 8a of the cylinder body 8, respectively. Is pivotally supported by a spindle B, and is pivotally supported by a spindle C with respect to the lever mounting portions 8a and 8a.
[0020]
The brake lever 5 at the time of non-operation is urged in the non-operation direction in front of the vehicle body by the elastic force of the return spring 14 transmitted through the master piston 10 and the push rod 6, and the backward limit of the brake lever 5 is connected to the connecting arms 5d and 5d. It is regulated by contact between the front end surface and the front body wall of the cylinder body 8.
[0021]
Each of the support shafts A and B is located at an equal distance from the support shaft C with a radius R1, and a length L5 that is twice the radius R1 is provided between the support shafts A and B, and the brake lever 5 is moved backward as described above. When positioned at the limit, the support shafts A, B, and C are set to be positioned on a line L4 orthogonal to the cylinder center axis L3. Further, the support shaft A corresponds to the operating point of the brake lever 5 (the operating point A of the present invention), the support shaft C corresponds to the support point of the brake lever 5, and the grip operating portion 5b of the brake lever 5 from the support shaft C. The ratio L1 / L2 between the length L1 to the force point D and the length L2 from the support shaft C to the support shaft A connecting the working arm 5a of the brake lever 5 and the outer end of the push rod 6 is The lever ratio of the lever 5 is obtained.
[0022]
The hydraulic master cylinder device 1 for a bar handle vehicle according to the present embodiment is configured as described above. When the brake lever 5 is not operated, the brake lever 5 is in the state shown in FIG. The push rod 6 and the master piston 10 are positioned at the retreat limit, the valve stem 12 is in contact with the stopper pin 17, the head 12 a is separated from the stem hole 11, and the hydraulic pressure chamber 13 and the oil supply chamber 16 are located. And communicate with each other.
[0023]
When the brake lever 5 is gripped and operated from the non-actuated state of FIG. 1, the connecting rod 7 rotates about the support shaft C, and the support shaft B moves on an arc of radius R1 centering on the support shaft C. The brake lever 5 rotates about the support shaft C, and the support shaft A pushes the cylinder center axis L3 toward the bottom of the cylinder hole 9 with a length L5 from the support shaft B rotating on the arc of radius R1. The entire push rod 6 is moved and pushed toward the bottom of the cylinder hole 9 on the cylinder center axis L3 by the guide of the support shaft A moving on the cylinder center axis L3 and the large-diameter sliding portion 6a.
[0024]
The master piston 10 in the cylinder hole 9 strokes the cylinder hole 9 toward the bottom by pushing the large-diameter sliding portion 6a of the push rod 6, and the master piston 10 comes into contact with the head portion 12a of the valve stem 12. The valve stem 12 is interlocked in the bottom direction of the cylinder hole 9, and the head portion 12 a of the valve stem 12 closes the stem hole 11 to block the communication between the hydraulic chamber 13 and the oil supply chamber 16, and then the hydraulic chamber 13 The pressure of the hydraulic fluid is increased, and the hydraulic fluid is supplied from the output port 15 to the caliper of the front disc brake.
[0025]
Among the above operations, the L1 / L2 lever ratio is set to be large in the normal use range E from the start of the grip lever 5 operation until the predetermined hydraulic pressure required for the front disc brake is generated in the hydraulic chamber 13. In order to draw a gentle curve in the same manner as a conventional constant lever ratio (see FIG. 4), a high hydraulic pressure is generated in the hydraulic chamber 13 with a small grip operation (rotation amount) of the brake lever 5.
[0026]
Further, when the brake lever 5 is greatly gripped and operated beyond the normal use range E, the support shaft A (action point) moves on the cylinder center axis L3 toward the bottom of the cylinder hole 9, and the support shaft C (support point). ), The length L2 of the support shaft C (support point) and the support shaft A (action point) gradually increases, and the stroke of the master piston 10 becomes inversely proportional as the L1 / L2 lever ratio decreases rapidly. Increase rapidly (see FIG. 4).
[0027]
In this embodiment, the lever ratio of the brake lever 5 is variable by the above configuration, and the L1 / L2 lever is used in the normal use range E until the predetermined hydraulic pressure required for the front disc brake is generated in the hydraulic chamber 13. By taking a large ratio, a high hydraulic pressure generated in the hydraulic chamber 13 can be supplied to the front disc brake with a small grip operation (rotation amount) of the brake lever 5.
[0028]
Further, a knockback is generated in the caliper piston of the front disc brake, and the braking gap between the disc rotor and the friction pad is expanded beyond a predetermined value, or the brake system from the oil supply chamber 16 of the hydraulic master cylinder 4 to the caliper of the front disc brake. When removing the air inside, the brake lever 5 is greatly rotated beyond the normal operating range E, so that the master piston 10 can be stroked greatly in a short time to increase the initial braking force, A large amount of air can be vented.
[0029]
Further, the push rod 6 pushed by the operating arm 5a of the brake lever 5 always moves on the cylinder center axis L3, so that it does not tilt as the operating lever is grasped unlike the conventional structure, and the master rod The piston 10 is not twisted or an unbalanced load is applied to the master piston 10 to reduce the operating force.
[0030]
In the above-described embodiment, since the working arm of the brake lever and the push rod are pivotally supported by the support shaft, this support shaft is used as the operation point A of the present invention. The outer end of the working rod may be rounded into a spherical shape and fitted into the concave portion of the working arm. In this case, the contact point between the outer end of the push rod and the concave portion of the working arm is the operation referred to in the present invention. This is the lever action point A. Further, the push rod may be rounded at its inner end into a spherical shape and fit into a recess provided at the outer end of the master piston. Even if the push rod is used alone as described above, the working arm and the master piston It is possible to arrange them on the cylinder central axis.
[0031]
In addition to the vertical center valve type shown in the embodiment, the hydraulic master cylinder of the present invention is a horizontal type that uses a cylinder hole in the vehicle body width direction, and a side port type that has a relief port on the peripheral wall of the cylinder body. Further, the present invention can be applied to a rear wheel brake and a clutch.
[0032]
【The invention's effect】
In the hydraulic master cylinder device for a bar handle vehicle according to the present invention, a push rod interposed between an operating arm of a control lever and a master piston is arranged on a cylinder central axis of the hydraulic master cylinder, and the push rod The contact point between the operating arm and the operating arm is defined as an operating point A of the operating lever. A connecting arm extends from the operating lever to the opposite side of the operating point A across the lever mounting portion of the hydraulic master cylinder. And one end of the connecting rod are pivotally supported by the support shaft B, the other end of the connecting rod and the lever mounting portion are pivoted by the support shaft C, and the action point A and the support shaft B are supported by the support shaft C. Since the lever ratio is large, the lever ratio is large in the normal use range of the hydraulic master cylinder, and the lever ratio gradually decreases after the normal use range.
[0033]
Therefore, in the normal use range until the predetermined hydraulic pressure required for brake and clutch operation is generated in the hydraulic chamber of the hydraulic master cylinder, a large lever ratio is adopted, so that a high fluid pressure can be achieved with a small number of operating levers. Pressure can be generated effectively, and when the braking gap and clutch interval are expanded more than specified, or when the air in the hydraulic system is vented, the operating lever can be moved beyond the normal operating range with a small lever ratio. Thus, it is possible to instantly fill the braking gap and the clutch interval to increase the start-up of the initial operation, and to release a large amount of air at a time to improve workability.
[0034]
In addition, the push rod pushed by the operating arm of the operating lever always moves on the center axis of the cylinder, so it does not tilt by gripping the operating lever unlike the conventional structure. And the master piston can be pushed without an unbalanced load to effectively generate a predetermined operating force.
[Brief description of the drawings]
FIG. 1 is a cross-sectional plan view of a non-operating state of a hydraulic master cylinder device showing an embodiment of the present invention.
FIG. 2 is a cross-sectional plan view of an operating state of a hydraulic master cylinder device showing an embodiment of the present invention.
3 is a cross-sectional view taken along the line III-III in FIG. 1 showing an embodiment of the present invention.
FIG. 4 is a relationship diagram between the amount of rotation of the operating lever and the stroke amount of the master piston.
[Explanation of symbols]
1 ... Hydraulic master cylinder device
2 ... Handlebar
4 ... Hydraulic master cylinder
5. Brake lever (operating lever of the present invention)
6 ... Push rod
5a ... Working arm
5b: Grip operation part
5c ... Extension
5d ... Connecting arm
7 ... Connecting rod
8 ... Cylinder body
8a ... Lever mounting part
9 ... Cylinder hole
10 ... Master piston
13 ... Hydraulic chamber
A ... Spindle (Operation point A of the present invention)
B, C ... spindle
R1 ... radius
L1: Length from the support shaft C to the force point D of the grip operating portion 5b
L2: Length from spindle C to spindle A
L3 ... Cylinder center axis
L4 ... Line perpendicular to the cylinder center axis L3
L5: Length between spindles A and B

Claims (1)

A master piston is inserted into the cylinder hole of the hydraulic master cylinder, a hydraulic chamber is defined at the bottom of the cylinder hole, and an operation lever is pivotally supported at the lever mounting portion of the hydraulic master cylinder. A push rod is interposed between the working arm and the master piston, and the operating piston is pushed toward the bottom of the cylinder hole by the rotation of the operation lever to boost the hydraulic fluid in the hydraulic chamber. In the hydraulic master cylinder device for a bar handle vehicle, the push rod is disposed on a cylinder central axis of the hydraulic master cylinder, and a contact point between the push rod and the working arm is an action point A of the operation lever. A connecting arm extends from the operation lever to the opposite side of the operating point A across the lever mounting portion, and the connecting arm and one end of the connecting rod are pivotally supported by a support shaft B. The lever mounting portion is pivotally supported by a support shaft C, and the action point A and the support shaft B are disposed at opposite positions equidistant from the support shaft C. Pressure master cylinder device.

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