JPH042157Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The present invention is a hydraulic master cylinder for a vehicle that operates the brakes of a vehicle using hydraulic pressure, and in particular, the actuation mechanism of a brake lamp switch provided on the cylinder body. Regarding.

[Conventional technology]

In conventional motorcycles, the brake switch, which lights up the stop light when the brake pedal is depressed, is fixed to the body frame near the brake pedal, and the switch and brake pedal are connected with wires, etc., so that they work together. Since the operating accuracy of the switch was low and the ease of assembly and maintenance was poor, a brake switch was provided in which the brake switch was mounted on the cylinder body of the hydraulic master cylinder, as shown in Japanese Utility Model Publication No. 58-23750, for example. has been done.

This technology involves fitting and fixing the switch case of the brake switch into a hole provided in the cylinder body that is approximately parallel to the push rod, and urging the mover stored in the storage recess of the case with an elastic member to close the switch case. The tip of the movable element protruding downward from the push rod is opposed to an operating piece or brake pedal protruding from the push rod.

[The problem that the idea attempts to solve]

However, in the above-mentioned device, if the tip of the movable element and the operating piece or brake pedal are provided apart from each other, the operating stroke becomes long, resulting in a lack of quick response, and a large installation space is required. Since the movable element is provided in contact with or close to the tip of the movable element, the movable element is susceptible to vibrations of the vehicle body and rocking of the push rod, which may cause malfunction.

SUMMARY OF THE INVENTION An object of the present invention is to provide a hydraulic master cylinder that is less susceptible to vibrations of the vehicle body and rocking of the push rod and is equipped with a switch operating mechanism with high operating accuracy.

[Means to solve the problem]

In order to achieve the above-mentioned object, the present invention is designed to bias the movable element stored in the storage recess of the switch case fixed to the cylinder body with an internal resilient member contracted at the bottom of the storage recess. In a hydraulic master cylinder for a vehicle, the tip of the movable element is arranged to protrude from the switch case, and an operating piece for pushing the tip of the movable element is protruded from a push rod that pushes a piston inside the cylinder body. and the operating piece, and the setting load of the external elastic member is set to be smaller than that of the internal elastic member when the push rod is not activated, and larger when the push rod is activated. It is characterized by the fact that

[Effect]

According to the above configuration, when the push rod is not activated, the movable element is held at a position where its tip protrudes from the switch case by the biasing force of the internal elastic member having a larger set load than the external elastic contact member.
In this state, even if the operation piece is subjected to vehicle body vibration or rocking of the push rod, the external elastic contact member absorbs this, so the mover is not affected and malfunction is prevented.

Further, when the push rod is operated, the setting load of the external elastic member becomes larger than that of the internal elastic member due to the advancement of the operation piece, and the operation piece is pushed into the storage recess of the switch case.

〔Example〕

An embodiment in which the present invention is applied to a vertical hydraulic master cylinder used in a rear brake of a motorcycle will be described below with reference to the drawings.

The hydraulic master cylinder 1 has a vertical cylinder body 2 fixed to the vehicle body, which is provided with a cylinder hole 3 that is open at the bottom. A piston 6 to be pushed is inserted in a fluid-tight and movable manner, and a hydraulic chamber 7 is defined between the bottom of the cylinder hole 3 and the piston 6.

A boss portion 2a is provided protruding from one side of the cylinder body 2, and a relief port 9 and a supply port 10 are bored in a side wall portion between the communication hole 8 and the cylinder hole 3 in the boss portion 2a. In addition, a discharge port 1 is provided on the upper wall of the cylinder body 2 to supply the pressurized fluid generated in the hydraulic pressure chamber 7 to the rear brake (not shown).
1 is formed.

A large-diameter hole 12 that opens downward is connected to the lower part of the cylinder hole 3, and a stopper 14 that is engaged with a circlip 13 fitted in the large-diameter hole 12 has a head 5a of the push rod 5 that can be pulled out. A return spring 15 is contracted in the hydraulic pressure chamber 7 to spring the piston 6.
is urged by the elastic force of the return spring 15 to a non-operating position where it comes into contact with the head 5a of the push rod 5.

A reservoir connection connector 16 is fluid-tightly attached to the boss portion 2a of the cylinder body 2 by fitting the fitting protrusion 16a into the communication hole 8.
An end of a hose 18 for replenishing the hydraulic fluid in the reservoir 17 into the cylinder hole 3 is connected to the connecting pipe portion 16b by a clamp 19.

At the bottom of the boss part 2a, a brake switch 20 for the rear brake is attached to a switch case 21 with a screw 2.
2, and between the lower part of the cylinder body 2 and the shaft of the push rod 5 is a boot that covers the opening of the large diameter hole 12 and the lower part of the brake switch 20 and expands and contracts as the push rod 5 moves up and down. 23 is attached to the boot 23, and within the boot 23 there is an operating piece 24 disposed on the shaft of the push rod 5 with its tip protruding below the brake switch 20.
is fixed.

The brake switch 20 operates a rear brake, which brakes the rear wheels with pressure fluid supplied from a hydraulic chamber 7, to a stop lamp at the rear of the vehicle in conjunction with a push rod 5 that moves upward when the brake pedal 4 is depressed. This is a lighted display, switch case 2
A movable element 25 is disposed in the storage recess 21a of No. 1 so as to be movable up and down. An external spring 27 is compressed between the operating piece 24 and the operating piece 24 .

A ring-shaped movable contact 28 is fitted on the outer periphery of the approximately intermediate portion of the movable element 25, and a movable contact 28 is fitted in the storage recess 21a.
A pair of fixed contacts 30, 30 are connected to the internal spring 2
6, and both fixed contacts 30, 3
0 is connected to the stop lamp by a lead wire 29.

Guide protrusions 25b, 25b, 24a that engage with the ends of the springs 26, 27 are protruded from both ends of the movable element 25 and the upper surface of the operating piece 24.
Both springs 26 and 27 are prevented from coming off.

The inner and outer springs 26 and 27 are compression coil springs corresponding to the inner and outer elastic members of the present invention, respectively, and when the push rod 5 is not operated, the inner spring 26
＞In addition to the external spring 27, push rod 5
When in operation, the internal spring 26 is set to be less than the external spring 27.

That is, in the brake switch 20, when the brake pedal 4 is not depressed and the brake is not applied, the elastic force of the internal spring 26 is greater than that of the external spring 27, and the head 25a of the mover 25 protrudes from the lower part of the switch case 21. It turns OFF when it is in the position shown in Figures 1 and 2.

Also, during braking when the brake pedal 4 is depressed, the operating piece 24 compresses the external spring 27 as the push rod 5 moves upward, and when the elastic force of the external spring 27 becomes larger than that of the internal spring 26, the operating piece 24 becomes movable. Child 25 is external spring 27
The movable contact 28 starts to move upward with the fixed contact 3.
When it comes into contact with 0 and 30, it turns ON and lights up the stop light.

As described above, in this embodiment, the brake switch 2
Since the external spring 27 facing the internal spring 26 is compressed between the actuator 25 of 0 and the operating piece 24 fixed to the push rod 5, the actuator 25 held by both springs 26 and 27 is Even if the actuator 25 is in this position, no rattling occurs, and the actuator 25 can operate smoothly.

In addition, the brake switch 20 has an operation piece 24 that is
Even if the push rod 5 is shaken due to vibrations of the vehicle body during driving or depression of the brake pedal 4, this is absorbed by the external spring 27, which prevents the mover 25 from malfunctioning and improves operational accuracy. .

Furthermore, since the movable element 25 does not malfunction due to vibration or rocking, the fixed contact 30 and the movable contact 28 can be disposed close to each other in a non-contact mode, which shortens the operating stroke and allows quick response. It also has excellent sex.

[Effect of idea]

As explained above, in the present invention, the movable element stored in the storage recess of the switch case fixed to the cylinder body is biased by the internal resilient member compressed into the storage recess, and the tip of the mover is pressed against the switch. An operating piece for pushing the tip of the movable element is protruded from a push rod that is arranged to protrude from the case and pushes the piston, and an external resilient member is compressed between the tip of the movable element and the operating piece. Since the set load of the external resilient member is set to be smaller than that of the internal resilient member when the push rod is not activated, and greater when the push rod is activated, the actuator held by both resilient members is No matter which position it is in, there is no wobbling and smooth operation is possible.

Furthermore, even if the operating piece is subjected to vibrations of the vehicle body or rocking of the push rod during driving, this is absorbed by the external resilient member, thereby preventing malfunction of the movable element and improving the accuracy of operation.

Furthermore, since the movable element does not malfunction due to vibration or rocking, the fixed contact and movable contact in non-contact mode can be placed close together, shortening the operating stroke and improving quick response. Excellent.

[Brief explanation of the drawing]

The figures show one embodiment of the present invention. Figure 1 is a cross-sectional view of the main parts of a hydraulic master cylinder, and Figure 2 is a cross-sectional view of the same hydraulic master cylinder assembled for the rear brake of a motorcycle. It is a front view. 1...Hydraulic pressure master cylinder, 2...Cylinder body, 3...Cylinder hole, 4...Brake pedal, 5...Push rod, 6...Piston, 1
2... Large diameter hole, 20... Brake switch, 21
...Switch case, 21a...Storage recess, 24
...Operation piece, 25...Movable element, 25a...Head,
26... Internal spring, 27... External spring, 28... Movable contact, 30... Fixed contact.

Claims (1)

[Scope of utility model registration request] The movable element, which is stored in the storage recess of the switch case fixed to the cylinder body, is biased by an internal resilient member contracted at the bottom of the storage recess so that the tip of the mover protrudes from the switch case. In a hydraulic master cylinder for a vehicle, in which an operating piece for pushing the tip of the movable element is protruded from a push rod for pushing an internal piston, an external elastic member is provided between the tip of the movable element and the operating piece. A hydraulic master cylinder for a vehicle, characterized in that the set load of the external resilient member is set to be smaller than that of the internal resilient member when the push rod is not in operation, and greater when the push rod is in operation. .