JP2004217211A - Disk brake for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To bring input and output power to and from a rear wheel brake close to an ideal distribution level by restraining a braking force transmitted to the rear wheel brake through an actuator with a simple inside structure without using a separate fluid pressure reducing means, while applying a mechanical brake operable on the pressure fluid of a pressure fluid master cylinder to the rear wheel brake. <P>SOLUTION: A mechanical drum brake is used for the rear wheel brake 5. The fluid pressure pipeline 8 is connected to a front wheel brake 4. A cylinder bore 43 of the actuator 40 is partitioned into a fluid pressure chamber 45 and an atmospheric chamber 46 with a piston 44. A fluid pressure pipeline 9 is connected to the fluid pressure chamber 45. A brake cable 12 is connected to a cylinder rod 41. Two springs 48, 49 with a different set load are housed in the atmospheric chamber 46 in a compressed state sandwiching a slide plate 47 therebetween. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

  The present invention relates to a brake device for a bar-handle vehicle that steers a vehicle body with a handlebar, such as a motorcycle, a three-wheeled vehicle, a three- or four-wheeled buggy, a golf cart and a snowmobile, and particularly uses a brake lever. The present invention relates to a brake device configured to operate a mechanical rear wheel brake using hydraulic fluid of a hydraulic master cylinder.

As a conventional technology combining a mechanical brake with a hydraulic system that generates hydraulic fluid in the hydraulic master cylinder by operating the brake lever, the hydraulic pipe connected to the hydraulic master cylinder and the mechanical brake are towed. An actuator is interposed between the actuator and the brake cable, and the hydraulic operation of the hydraulic master cylinder is converted into mechanical operation by the actuator to operate the mechanical brake. While utilizing both of the functional characteristics, the loss due to the elongation of the brake wire is reduced to improve the sense of rigidity of the brake lever, and it is possible to prevent the occurrence of vapor lock due to the braking heat (for example, see Patent Document 1). .).
Japanese Utility Model Publication No. 2-57767

  By the way, when the braking force is applied to the running vehicle, the weight of the vehicle body moves to the front side of the vehicle body due to the inertial force, and the load on the rear side of the vehicle body required for rear wheel braking is reduced. It is well known that it is preferable to appropriately reduce the pressure fluid. However, when the above-mentioned mechanical brake is applied to the rear wheel brake of a bar handle vehicle, a PCV (pressure control valve) or a P valve (proportioning) is used. A liquid pressure reducing means such as a valve) must be separately provided, which inevitably increases the cost, the weight of the vehicle body, and the number of assembly steps.

  Therefore, the present invention applies a mechanical brake operated by the hydraulic fluid of a hydraulic master cylinder to a rear wheel brake, and employs an actuator having a simple internal structure without using a separate hydraulic pressure reducing means. The purpose of the present invention is to suppress the braking force on the rear wheel brake so that the input / output pressure for the rear wheel brake approaches the ideal distribution.

  The present invention relates to a bar handle vehicle brake device that operates a rear wheel brake by a hydraulic system in which a hydraulic pipe is connected to a hydraulic master cylinder operated by a brake lever, wherein the rear wheel brake is pulled by a connecting means. An operating force converter in which a mechanical brake to be operated is provided, and a cylinder hole inside a cylinder body is defined between a hydraulic chamber and an atmospheric chamber by a piston integrated with a cylinder rod between the connecting means and the hydraulic pipe. An actuator for connecting the hydraulic pipe to the hydraulic chamber, and connecting the connecting means by projecting a tip of the cylinder rod to the outside of the cylinder body, wherein the cylinder rod is connected to the piston of the piston. The mechanical brake is actuated by being drawn into the cylinder body by movement and towing the linking means.

  In addition to directly connecting the cylinder rod of the actuator to the connecting means, an appropriate transmitting means such as a link mechanism may be interposed. Also, when a mechanical drum brake is used as the rear wheel brake, it does not occupy a large space, unlike a mechanical disk brake overhanging a disc rotor or caliper body. The wheel hub is used for the brake drum, and the drum brake is housed in the wheel hub even in a scooter-type vehicle with a small diameter and a power unit integrated with an engine, a power transmission mechanism, and a transmission mechanism on one side of the rear wheel. Can be arranged.

  According to the above invention, the hydraulic fluid generated in the hydraulic master cylinder by the gripping operation of the brake lever is supplied from the hydraulic piping to the hydraulic chamber of the actuator, and the piston is pushed toward the atmospheric chamber while expanding the hydraulic chamber. The cylinder rod moves to slide the cylinder rod integral with the piston, and the cylinder rod pulls the connecting means to operate the rear wheel brake.

  At the initial stage of movement of the piston, one of the two springs set in the atmosphere chamber is compressed with one of the springs having a lower set load. When the set load of one spring increases to the set load of the other spring, which has a higher set load, both springs are compressed while moving the slide plate sandwiched therebetween.

  The compression load of the two slip rings compressed by the movement of the piston becomes the stroke resistance of the cylinder rod, and in the first half of the piston braking when only one of the springs having a low set load is compressed, the cylinder rod makes a large stroke. In the latter half of braking in which the other spring with a high load is also compressed at the same time, the stroke resistance increases, and the stroke amount of the cylinder rod decreases. Accordingly, since the operating force of the rear wheel brake towed by the slide of the cylinder rod through the connecting means is reduced from the stage where the other spring having a high set load is compressed, the operation of the rear half brake of the rear wheel brake is performed. Power is weakened.

  ADVANTAGE OF THE INVENTION According to the brake device for bar-handle vehicles of this invention, the actuator reduces the operating force in the latter half of braking of the rear wheel brake, in addition to the operating force conversion function of converting the hydraulic operating force to the rear wheel brake into mechanical operating force. It also has a function to reduce the operating force, and while adopting a small and inexpensive mechanical brake for the rear wheel brake, it does not require a separate hydraulic pressure reduction means such as a PCV or P-valve. A good braking force as a wheel brake can be set at low cost, the weight of the vehicle body can be reduced, and the number of assembly steps can be reduced.

  In addition, since the inside of the actuator has a simple structure, it can be manufactured at a lower cost while improving reliability and durability. When a mechanical drum brake is used for the rear wheel brake, the drum brake can be stored in the wheel hub of the rear wheel, and a disk rotor or caliper body is mounted on the side of the rear wheel like a disk brake. Because it does not need to occupy the space of the rear wheel, especially the soft bike with the small wheel diameter of the rear wheel, the wheel diameter of the rear wheel is small, and the engine, power transmission mechanism and transmission mechanism are integrated on one side of the rear wheel It is suitable for a scooter type vehicle provided with a power unit.

  Hereinafter, an embodiment of the present invention will be described with reference to FIG. In the brake device 1, the front wheel brakes 4 and the rear wheel brakes 5 are operated by brake operation means provided at one end of a body steering handlebar of a bar handle vehicle.

  The brake operating means 2 is a combination of a brake lever 6 and a tandem type hydraulic master cylinder 7. Two hydraulic pipes 8, 9 for front and rear wheel brakes are connected to the hydraulic master cylinder 7. The front and rear wheel brakes 4 and 5 are simultaneously operated by the hydraulic fluid generated in the hydraulic master cylinder 7 by the gripping operation of the brake lever 6 with two hydraulic systems.

  As the front wheel brake 4, a hydraulic disc brake that operates the caliper body 10 with the hydraulic fluid generated by the hydraulic master cylinder 7 to brake the disc rotor 11 is used. Are connected. Further, a mechanical drum brake pulled by a brake cable 12 is used for the rear wheel brake 5. One end of the brake cable 12 is connected to a hydraulic pipe 9 for the rear wheel brake via an actuator 40. The other end is connected to an operating lever 14 pivotally supported by a back plate 13 of the rear wheel brake 5.

  A hydraulic pressure control device 17 generally called an ABS (anti-lock brake system) is interposed in the hydraulic pressure pipes 8 and 9, and the hydraulic fluid supplied from the hydraulic master cylinder 7 to the hydraulic pressure pipes 8 and 9 is provided. When the vehicle speed and road surface conditions are excessive, the hydraulic pressure control device 17 adjusts this to effectively prevent the front and rear wheels from being locked, and allows the vehicle to stop at the shortest braking distance in a stable vehicle posture. ing.

  The actuator 40 is an operating force converting mechanism for converting the hydraulic operating force from the brake operating means 2 to the rear wheel brake 5 into a mechanical operating force. The actuator 40 has a cylinder hole 43 inside the cylinder body 42 integrated with the cylinder rod 41. A hydraulic chamber 45 and an atmosphere chamber 46 are defined by a piston 44, and a hydraulic pipe 9 for a rear wheel brake is connected to the hydraulic chamber 45. The cylinder rod 41 disposed on the central axis of the hydraulic chamber 45 and the atmosphere chamber 46 protrudes from the bottom wall of the hydraulic chamber 45 to the outside, and the front end thereof is directly connected to the brake cable 12 for the rear wheel brake cable. Have been.

  In the atmosphere chamber 46, a spring 48 having a small set load is provided on the piston side and a spring 49 having a large set load is provided on the tip side of the cylinder rod with the slide plate 47 interposed therebetween. A vent hole 50 for sucking and discharging air in the atmosphere chamber 46 when the springs 48 and 49 expand and contract is formed in the chamber-side bottom wall.

  The hydraulic fluid branched from the hydraulic master cylinder 7 to the hydraulic brake pipe 9 for the rear wheel brake by the gripping operation of the brake lever 6 enters the hydraulic chamber 45 of the actuator 40 and compresses both springs 48 and 49. The piston 44 is pushed toward the atmosphere chamber. The cylinder rod 41 is drawn into the cylinder by the movement of the piston 44, pulls the brake cable 12, rotates the operation lever 14, and operates the rear wheel brake 5.

  On the rear wheel brake 5 side where the above-mentioned braking operation is released, the return spring 29 compressed by the rotation of the operating lever 14 at the time of braking is restored in the extension direction, and the brake cable 12 is pulled in the rear wheel brake direction. Then, the cylinder rod 41 of the actuator 40 is pulled out of the cylinder body, and the hydraulic fluid that has expanded the hydraulic chamber 45 is returned to the hydraulic master cylinder 7 to return to the non-operating state.

  Furthermore, in the above-described embodiment, the description has been made using the brake cable as the connecting means for the rear wheel brake. However, it is also possible to connect a plurality of rods or use both rods and brake cables. The two springs having different set loads may be provided on either side of the slide plate. In the present embodiment, the hydraulic operation of the rear wheel brake is described in conjunction with the front wheel brake, but the present invention can also use a hydraulic system for the rear wheel brake exclusively.

  Also, if a mechanical drum brake is used for the rear wheel brake, the drum brake can be stored in the wheel hub of the rear wheel, and the space for the disk rotor and caliper body on the side of the rear wheel like a disk brake. Since it does not need to be occupied, a soft bike with a small rear wheel diameter or a power unit with a small rear wheel diameter and an integrated engine, power transmission mechanism and transmission mechanism are provided on one side of the rear wheel. Suitable for scooter type vehicles.

FIG. 1 is a schematic view of a brake device for a bar handle vehicle showing a first embodiment of the present invention.

Explanation of reference numerals

    DESCRIPTION OF SYMBOLS 1 ... Brake device, 2 ... First brake operation means, 4 ... Front wheel brake using hydraulic disc brake, 5 ... Rear wheel brake using mechanical drum brake, 6 ... Brake lever, 7 ... Hydraulic master cylinder, 8 ... Hydraulic piping for front wheel brake, 9 ... Hydraulic piping for rear wheel brake, 12 ... Brake cable for pulling rear wheel brake, 13 ... Back plate, 14 ... Activating lever, 29 ... Return spring, 40 ... Actuator, 41: Cylinder rod, 42: Cylinder body, 43: Cylinder hole, 44: Piston, 45: Hydraulic chamber, 46: Atmosphere chamber, 47: Slide plate, 48: Small set load spring, 49: Set load Big spring

Claims (1)

In a bar handle vehicle brake device that operates a rear wheel brake by a hydraulic system in which a hydraulic pipe is connected to a hydraulic master cylinder operated by a brake lever, a machine in which the rear wheel brake is towed by a connecting means. An actuator for operating force conversion, in which a cylinder hole inside a cylinder body is defined by a piston integrated with a cylinder rod into a hydraulic chamber and an atmospheric chamber between the connecting means and the hydraulic pipe, And connecting the hydraulic pressure pipe to the hydraulic chamber, connecting the connecting means by projecting the tip of the cylinder rod to the outside of the cylinder body, and moving the piston by moving the piston. A brake device for a bar handle vehicle, wherein the brake device is drawn into a body and pulls the connection means to operate the mechanical brake.

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