JPH086658Y2 - Hydraulic master cylinder for rear wheel brakes - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a hydraulic master cylinder for hydraulically operating a rear wheel brake of a motorcycle such as a motorcycle.

[Conventional technology]

A hydraulic master cylinder of this type used for a rear wheel brake of a motorcycle such as a motorcycle has a vertical cylinder body having two mounting flanges, as disclosed in Japanese Utility Model Laid-Open No. 55-32273. It can be attached to the vehicle body frame with mounting bolts.

A piston for hydraulic pressure generation is inserted in a cylinder hole formed in the cylinder body, and a push rod for pushing the piston is vertically arranged below the cylinder body. The lower end of the push rod is connected to the rear end of the brake pedal pivotally supported by the vehicle body frame, and the head of the upper end that supports the piston is retained by a locking ring that is engaged with the cylinder hole (for example, (See JP-A-60-50063).

The hydraulic master cylinder configured as described above is a push rod that moves upward when the brake pedal is depressed,
The piston is pushed into the cylinder hole to generate a hydraulic pressure in the hydraulic chamber defined in the upper bottom portion of the cylinder hole. The generated hydraulic pressure is further sent to the rear wheel brake via the brake hose, and the rear wheel brake is hydraulically operated to control the rear wheel.

[Problems to be solved by the device]

However, in the above-mentioned push rod, the connection point with the brake pedal makes an arc motion by pedal operation,
The head that receives this circular arc motion is mounted in an unstable state in which neither end is fixed, just inserted through the large diameter hole of the locking ring. Alternatively, since the head of the push rod shakes its head, the piston is twisted by the push rod, which not only causes wear but also impairs smooth operation.

Therefore, the present invention is an inexpensive hydraulic master cylinder for the rear wheel brake that minimizes the influence of the swinging of the push rod and prevents the piston from being damaged due to the twisting of the push rod, and that enables smooth brake operation. It is intended to be provided to.

[Means for solving the problem]

In order to achieve the above object, the present invention provides a hydraulic master cylinder for a rear wheel brake, in which a hydraulic pressure generating piston inserted in a cylinder body is pushed by the operation of a push rod connected to a brake pedal. A rotation lever is pivotally supported on the vehicle body frame by using a vehicle body mounting flange provided on the cylinder body and one of mounting bolts inserted through the flange, and an action piece of the rotation lever is attached to the rear of the piston. It is characterized in that it is in contact with the end and the tip of the push rod is swingably connected to a turning lever.

[Action]

With this configuration, when the push rod is operated by depressing the brake pedal, the piston inside the cylinder body rotates about one mounting bolt that serves as a pivot, and the action piece of the pivot lever operates. Generates hydraulic pressure inside the cylinder body by pushing the piston.

Since the tip of the push rod is supported by a rotating lever that is interposed between the push rod and the piston, it is possible to minimize swinging that swings off the cylinder axis and to rotate the power from the brake pedal. Smooth and efficient transmission to the lever becomes possible. Since the action piece of the rotating lever, which replaces the push rod, pushes the piston, the influence of the swing of the push rod is hardly transmitted to the piston, and the piston is smoothly pushed by the turning lever. Wear due to prying is prevented as much as possible.

〔Example〕

 An embodiment of the present invention will be described below with reference to the drawings.

A brake pedal 1 for activating the rear brake of a motorcycle is provided so as to be rotatable in the vertical direction with its intermediate portion pivotally supported by a body frame (not shown) by a pivot shaft 2. In the hydraulic master cylinder 3 that generates hydraulic pressure by stepping on the pedal 1, a vertical cylinder body 4 is similarly attached to the vehicle body frame above the rear end 1b of the brake pedal 1.

A pedal plate 5 for stepping operation is fixedly provided at a front end 1a of the brake pedal 1, and a rear end 1b is provided with a pin 7 at a lower end of a push rod 6 vertically arranged between the brake pedal 1 and the cylinder body 4. The return spring 8 is connected to the vehicle body frame and is urged in the non-operating direction at all times.

A piston 10 for hydraulic pressure generation is inserted in a cylinder hole 9 formed in the cylinder body 4 so as to be opened downward so as to be liquid-tight and movable, and between the upper bottom portion of the cylinder hole 9 and the piston 10. A return spring 12 that biases the piston 10 in the non-operating direction is contracted in the hydraulic chamber 11 that is defined.

A boss portion 4a for connecting a reservoir is provided on one side of the cylinder body 4 and a brake lamp switch 13 is fixedly provided on the lower side of the boss portion 4a. The boss 4a is provided with a liquid passage port 16 communicating with the cylinder hole 9 through the relief port 14 and the supply port 15, and the liquid passage port 16 is provided.
A connector 18 for connecting a reservoir hose 17 of a separately arranged reservoir (not shown) is fitted to 16 so as to replenish the cylinder hole 9 with the working fluid stored in the reservoir. .

The cylinder body 4 has a mounting flange for mounting on the vehicle body frame on a diagonal line that sandwiches the cylinder hole 9.
Brake lamp 4b, 4b, 4c is extended and the cylinder body 4 is fixed by screwing a mounting bolt 19 which is inserted into the shaft hole 4d of these mounting flanges 4b, 4b, 4c to the vehicle body frame. A rotation lever 20 is pivotally attached to a mounting bolt 19 on the switch 13 side.

As shown in FIG. 2, the mounting flanges 4b and 4b are provided below the brake lamp switch 13 so as to vertically project in a pair in the vertical direction with respect to the other mounting flange 4c used in one piece. Sandwiches the space between the first arm 20a and the second arm 20b between the mounting flanges 4b and 4b,
The mounting bolt 19 is inserted into the shaft holes 4d, 4d, 20c of the rotary lever 20 and b, 4b, and is mounted together with the cylinder body 4 on the flange 21 of the vehicle body frame.

The tip of the first arm 20a interposed between the piston 10 and the push rod 6 is bifurcated into a connecting piece 20d and a working piece 20e, and the tip of the push rod 6 has a pin 22 on the connecting piece 20d. The other action piece 20e which is swingably connected to the piston 10 and has an arcuate outer surface is disposed in contact with the rear end of the piston 10.

As described above, when the rotating lever 20 is not connected to the push rod 6, the connecting piece 20d is pulled by the return spring 8 of the brake pedal 1 and the operating piece 20e is connected.
Is rotated counterclockwise in FIG. 1 with the mounting bolt 19 of the mounting flange 4b as a fulcrum in response to the push of the piston 10 elastically urged by the return spring 11, and the second arm 20b.
The stopper 20f at the tip comes into contact with the boss portion 4a of the caliper body 4 to restrict the retreat limit of the rotary lever 20 and the piston 10, and the stopper 20f serves as the brake lamp switch 1
The operator 13a of 3 is pushed in to turn off the switch 13.

When the brake pedal 1 is depressed, the rear end
1b pushes up the push rod 6, and the rotation lever 20
The mounting bolt 19 is pivoted clockwise as shown in FIG. 1, the stopper 20f is separated from the boss 4a, the brake lamp switch 13 is turned on, and the action piece 20e is turned on by the piston 1a.
By moving 0 upward, a hydraulic pressure is generated in the hydraulic chamber 11. Hydraulic chamber 11
The generated hydraulic pressure is sent from the discharge port 23 to the rear wheel brake through the brake hose, and the rear wheel brake is hydraulically operated to brake the rear wheel.

In this embodiment, the tip of the push rod 6 is the piston 10
The piston 10 is supported by a rotary lever 20 interposed between the rotary lever 20 and the push rod 6 instead of the push lever 6.
Since the action piece 20e of is pushed, the influence of the unnecessary swing of the push rod 6 is hardly transmitted to the piston 10. Therefore, the piston 10 is smoothly pushed by the turning lever 20 which does not swing, so that the occurrence of prying is suppressed and the wear due to prying is prevented.

Further, since the push rod 6 itself is also supported by being connected to the connecting piece 20d of the turning lever 20, the swinging motion that deviates from the cylinder axis and swings is suppressed as much as possible, and is input to the brake pedal 1. Transmitted power from the push rod 6 to the rotary lever 20 without waste, and the piston
10 can be pushed efficiently.

Further, the cylinder body 4 is a flange for mounting on the vehicle body.
4b, 4b and 4c are arranged diagonally across the cylinder hole 9 to support both sides of the cylinder hole 9, so that the cylinder body is mounted on one side of the body frame more sufficiently than the conventional example. Strength is obtained.

Moreover, since the mounting lever 19 that is inserted through the one flange 4b, 4b is used to pivotally support the rotating lever 20,
The attachment of the cylinder body 4 and the pivotal attachment of the rotary lever 20 can be performed at the same time, and the rotary lever does not require a dedicated support shaft so that the cylinder body does not have to be upsized and can be manufactured at low cost. . Further, the reaction force generated when the rotating lever 20 is rotated by the pushing motion of the push rod 6 is effectively supported by the mounting bolt 19 directly screwed to the flange 21 of the vehicle body frame. Can be efficiently transmitted to the rotating lever 20 to efficiently push the piston 10.

In the above embodiment, the turning lever is pivotally supported by the pair of flanges, but the present invention can be sufficiently mounted with only one flange.

As described above, it is preferable that the vehicle body mounting flange is arranged on a diagonal line that sandwiches the cylinder hole, because the mounting strength can be improved, but the mounting flange may be provided on the same side as in the conventional case. .

In addition to directly fixing the cylinder body to the vehicle body frame, a bracket may be interposed between the two as a mounting auxiliary member. By mounting the cylinder body using the bracket, the mounting position of the cylinder body can be freely set. Can be set.

[Effect of device]

As described above, according to the present invention, the turning lever is pivotally supported on the vehicle body frame by using the vehicle body mounting flange of the cylinder body and one of the mounting bolts inserted through the flange. By contacting the rear end of the piston and swingably connecting the tip of the push rod to the rotary lever, the piston is pushed by the action piece of the rotary lever, so that the neck of the push rod is not required. The influence of the swing is hardly transmitted to the piston, damage to the piston due to prying from the push rod is prevented, and the push rod itself is also suppressed as much as possible by swinging with the turning lever. The power input to the brake pedal can be efficiently transmitted to the rotating lever to efficiently push the piston.

Moreover, since this rotation lever is pivotally supported by using the flange for fixing the cylinder body to the vehicle body and the mounting bolt, the cylinder body can be mounted and the rotation lever can be pivotally attached at the same time, and the rotation lever can be simultaneously attached. In addition, there is no need for a dedicated support shaft, there is no need to upsize the cylinder body shape, and it can be manufactured at low cost. Further, since the reaction force generated when the rotating lever is rotated by the push movement of the push rod is effectively supported by the mounting bolt screwed directly to the body frame, the pushing force of the push rod is not wasted to the rotating lever. By transmitting it, the piston can be efficiently pushed.

[Brief description of drawings]

FIG. 1 shows an embodiment of the present invention. FIG. 1 is a sectional front view showing a hydraulic master cylinder mounted on a vehicle body, and FIG. 2 is a side view of the hydraulic master cylinder. 1 ... Brake pedal, 3 ... Hydraulic master cylinder, 4
...... Cylinder body, 4b, 4b, 4c …… Mounting flange, 6
...... Push rod, 9 ...... Cylinder hole, 10 ...... Piston, 19 ...... Mounting bolt, 20 ...... Rotating lever, 20a ......
1st arm, 20b ... 2nd arm, 20c ... Shaft hole, 20d ... Connecting piece, 20e ... Working piece, 20f ... Stopper, 21 ... Body frame flange

Claims (1)

[Scope of utility model registration request] 1. A vehicle body provided in a cylinder body of a rear wheel brake hydraulic master cylinder in which a hydraulic pressure generating piston inserted in a cylinder body is pushed by the operation of a push rod connected to a brake pedal. 1 of a mounting flange and a mounting bolt that is inserted into the flange
The pivot lever is pivotally supported on the vehicle body frame by using one of them, the action piece of the pivot lever is brought into contact with the rear end of the piston, and the tip of the push rod is swingably connected to the pivot lever. A hydraulic master cylinder for rear wheel brakes.