JP2019094033A - Fluid pressure master cylinder for vehicle - Google Patents

Abstract

To provide a fluid pressure master cylinder which can reduce a size and weight of a cylinder body.SOLUTION: A communication path boss part 2c having a communication path 12 for making a cylinder hole 2a formed at a cylinder body 2 and a reservoir tank 3 communicate with each other therein, and a vehicle body attachment boss part 2d for attaching a fluid pressure master cylinder 1 to a vehicle body are integrally formed at one side face of the cylinder body 2. The communication path 12 comprises a communication hole 13 extending downward in parallel with a center axis CL1 of the cylinder body 2 from a bottom wall 3a of the reservoir tank 3, a relief port 14 orthogonal to the communication hole 13, and opened at the cylinder hole 2a, and a supply port 15.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a vehicle hydraulic pressure master cylinder, and more particularly, to a vertical vehicle hydraulic pressure master cylinder integrally provided with a reservoir tank storing hydraulic fluid.

  Conventionally, in a vehicle hydraulic master cylinder including a reservoir tank integrally storing a working fluid at the upper end of a vertically long cylinder body, the center axis of which is oriented in the vertical direction of the vehicle body, one side surface of the cylinder body There have been provided communication path bosses provided internally with a communication passage communicating with a cylinder hole formed in a cylinder body, and a vehicle body mounting boss portion provided on the other side (see, for example, Patent Document 1). ).

Patent No. 4100951

  However, in the case of the above-mentioned Patent Document 1, the cylinder for the cylinder body is provided in the radial direction since the communication path boss is provided on one side of the cylinder body and the vehicle body mounting boss on the other side. The size was too big and the weight was too big.

  Then, an object of this invention is to provide the hydraulic-pressure master cylinder for vehicles which can attain size reduction and weight reduction of a cylinder body.

  In order to achieve the above object, in a vehicle hydraulic master cylinder of the present invention, a reservoir tank for storing hydraulic fluid is integrated with an upper end portion of a cylinder body disposed on the vehicle body with the central axis directed in the vehicle body vertical direction. In the vehicle hydraulic pressure master cylinder, the communication passage boss portion is internally provided with a communication passage for communicating the cylinder hole formed in the cylinder body with the reservoir tank on one side surface of the cylinder body. A first communication hole is integrally formed with a pair of vehicle body mounting bosses for mounting the vehicle hydraulic pressure master cylinder to the vehicle body, and the communication passage extends downward from the bottom wall of the reservoir tank; A second communication hole is provided which intersects the first communication hole and opens in the cylinder hole.

  Preferably, at least one of the vehicle body mounting bosses is integrally formed with the communication path bosses. Furthermore, it is preferable that the first communication hole extends downward in parallel with the central axis of the cylinder body. Preferably, a union boss portion provided with a union hole communicating with the cylinder hole is protruded from one side surface of the cylinder body.

  According to the fluid pressure master cylinder for a vehicle of the present invention, the cylinder for the radial direction of the cylinder body is formed by integrally forming the communication passage boss having the communication passage therein and the vehicle body mounting boss on one side surface of the cylinder body. The cylinder body can be reduced in size and weight as much as possible.

  Furthermore, by forming at least one of the vehicle body mounting bosses integrally with the communication path bosses, it is possible to prevent the cylinder body from being enlarged in the radial direction, thereby further reducing the size and weight of the cylinder body. Can be Further, by extending the first communication hole downward in parallel with the central axis of the cylinder body, the boss for the communication passage can be prevented from becoming large in the radial direction of the cylinder body.

  Further, by providing the union hole on one side surface of the cylinder body provided with the communication passage boss, the cylinder body can be further miniaturized and reduced in weight, and the union hole and the second communication hole are formed. The drilling direction at the time of processing can be matched, and the improvement of processability can be aimed at.

It is a front view of a hydraulic pressure master cylinder which shows one example of an embodiment of the present invention. It is a side view of a hydraulic pressure master cylinder similarly. It is a top view of a hydraulic pressure master cylinder similarly. FIG. 4 is a cross-sectional view taken along line IV-IV of FIG.

  FIG. 1 to FIG. 4 show an embodiment of the vehicle hydraulic pressure master cylinder of the present invention. The hydraulic pressure master cylinder 1 according to the present embodiment is, for example, used as a hydraulic pressure master cylinder for the rear wheel of a bar-handle vehicle, and has a longitudinal cylindrical shape with the central axis CL1 oriented in the vertical direction of the vehicle body. A reservoir tank 3 for storing hydraulic fluid is integrally provided at the upper end portion of the cylinder body 2 of the above.

  The cylinder body 2 is provided with a bottomed cylinder hole 2a open at the lower end, and the piston 4 is movably inserted into the cylinder hole 2a via the primary cup 5 and the secondary cup 6, and the piston 4 and cylinder are A hydraulic pressure chamber 7 is defined between the upper wall 2b of the hole 2a.

  A return spring 8 is compressed between the piston 4 and the upper wall 2b, and the piston 4 is biased toward the lower side of the vehicle body by the elastic force of the return spring 8 and the retraction limit thereof is It is regulated by the contact with the head 10a of the push rod 10 engaged with the circlip 9 engaged with the opening of the cylinder hole 2a. The rear end of the brake pedal 11 is rotatably connected to the push rod 10 projecting from the lower end of the cylinder body 2.

  The reservoir tank 3 includes a reservoir 3b having a bottom wall 3a orthogonal to the central axis CL1, a cap 3c attached to the upper opening of the reservoir 3b, and a diaphragm 3d interposed therebetween. There is.

  A communication passage boss 2c is provided on one side of the cylinder body 2, and a communication passage 12 is formed in the communication passage boss 2c to communicate the reservoir 3 with the cylinder hole 2a. The communication passage 12 opens in the bottom wall 3a of the reservoir tank 3 and extends perpendicularly to the communication hole 13 (a first communication hole of the present invention) which extends downward in parallel with the central axis CL1. And a relief port 14 (a second communication hole of the present invention) opening in the cylinder hole 2a, and a supply port 15 (a second communication hole of the present invention), and the communication hole 13 and the relief port 14 and the supply port 15 The hydraulic fluid flows between the reservoir 3 b of the reservoir tank 3 and the fluid pressure chamber 7 through the same.

  Further, on one side portion of the cylinder body 2, a pair of vehicle body mounting bosses 2d, 2d for attaching the hydraulic pressure master cylinder 1 to the vehicle body frame are integrally provided on the cylinder hole opening side and the bottom side respectively. Furthermore, one of the vehicle body mounting bosses 2d provided on the cylinder hole bottom side is integrally formed with the communication path boss 2c. A union boss 2e is integrally provided on one side of the cylinder body 2, and a union hole 2f communicating with the fluid pressure chamber 7 is formed in the union boss 2e. Further, the union boss 2e is provided with protrusions 2g, 2g for preventing rotation of the banjo connected to the union hole 2f.

  In the hydraulic master cylinder 1 thus formed, when the brake pedal 11 is operated, the push rod 10 is moved upward to push the piston 4 in the upward direction of the cylinder hole 2 a, and the primary cup 5 acts as a relief port 14. Is closed, the hydraulic fluid in the fluid pressure chamber 7 is gradually pressurized. The hydraulic fluid pressurized in the fluid pressure chamber 7 is supplied from the union hole 2f to the rear wheel brake through the brake hose.

  In this embodiment, as described above, the communication path boss portion 2c having the communication path 12 inside, the vehicle body mounting boss portions 2d and 2d, and the union boss 2f on one side of the cylinder body 2 By integrally forming the part 2e, it is possible to prevent the cylinder body 2 from being enlarged in the radial direction as much as possible, and to achieve the miniaturization and the weight reduction of the cylinder body 2.

  Further, by extending the communication hole 13 downward in parallel with the central axis CL1 of the cylinder body 2, it is possible to prevent the communication path boss portion 2c from increasing in the radial direction of the cylinder body 2. Further, by providing the communication path boss portion 2c and the union boss portion 2e on one side surface of the cylinder body 2, the cylinder body can be further miniaturized and reduced in weight, and the union hole 2f and the relief are also provided. When forming the port 14 and the supply port 15, the drilling direction can be matched, and the processability can be improved.

  The present invention is not limited to the embodiment described above, and the first communication hole may not be parallel to the central axis of the cylinder hole, and the second communication hole is not orthogonal to the first communication hole. Even if it crosses. Furthermore, both body attachment bosses may not be integrally formed with the communication path bosses, and both body attachment bosses may be integrally formed with the communication path bosses. Further, the hydraulic pressure master cylinder of the present invention is not limited to one used for the hydraulic pressure master cylinder of a bar-handle vehicle, but can be applied to a hydraulic pressure master cylinder for four wheels, and further to a hydraulic pressure master cylinder for clutches. Can also be applied.

  DESCRIPTION OF SYMBOLS 1 ... Liquid pressure master cylinder, 2 ... Cylinder body, 2a ... Cylinder hole, 2b ... Upper wall, 2c ... Boss part for communicating paths, 2d ... Body mounting boss part, 2e ... Union boss part, 2f ... Union hole, 2g ... Projection piece 3: Reservoir tank 3a Bottom wall 3b Reservoir 3c Cap 3d Diaphragm 4 Piston 4 Primary cup 6 Secondary cup 7 Hydraulic pressure chamber 8 Return Spring, 9: circlip, 10: push rod, 10a: head, 11: brake pedal, 12: communication passage, 13: communication hole, 14: relief port, 15: supply port

Claims (4)

A vehicle hydraulic pressure master cylinder integrally provided with a reservoir tank for storing hydraulic fluid at an upper end portion of a cylinder body disposed on the vehicle body with the central axis directed in the vertical direction of the vehicle body,
A communication passage boss portion internally provided with a communication passage for communicating the cylinder hole formed in the cylinder body with the reservoir tank on one side surface of the cylinder body, and the vehicle hydraulic pressure master cylinder attached to the vehicle body Integrally formed with a pair of body mounting bosses,
The communication passage includes a first communication hole extending downward from the bottom wall of the reservoir tank, and a second communication hole intersecting the first communication hole and opening in the cylinder hole. Vehicle hydraulic pressure master cylinder characterized in that The vehicle hydraulic pressure master cylinder according to claim 1, wherein at least one of the vehicle body mounting bosses is integrally formed with the communication path bosses. The vehicle hydraulic pressure master cylinder according to claim 1 or 2, wherein the first communication hole extends downward in parallel with a central axis of the cylinder body. The hydraulic pressure master cylinder for a vehicle according to any one of claims 1 to 3, wherein a union boss portion provided with a union hole communicating with the cylinder hole is protruded on one side surface of the cylinder body.

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