JP6596355B2 - Hydraulic master cylinder reservoir tank - Google Patents

Description

  The present invention relates to a reservoir tank that stores hydraulic fluid for operating hydraulic master cylinders of motorcycles and motorcycles, and more particularly to a structure of a diaphragm used in the reservoir tank.

  Conventionally, as a reservoir tank of a hydraulic master cylinder, there is one whose horizontal cross section is formed in a rectangular shape, and a diaphragm used in this reservoir tank has a rectangular outer shape corresponding to the shape of the reservoir tank, A flange portion at the outer end placed on the upper opening edge of the reservoir body having the liquid storage chamber, a bellows portion provided inside the flange portion, and an inner end of the bellows portion at the lower end inside the hydraulic fluid. (See, for example, Patent Document 1).

Japanese Utility Model Publication No. 62-80748

  However, in the diaphragm disclosed in Patent Document 1 described above, the bellows portion is formed in a rectangular shape. When the diaphragm is pulled toward the bottom side of the reservoir tank when the hydraulic path is evacuated when filling the hydraulic fluid, the bellows portion is formed. In some cases, the corners of the part stretched and buckled, causing creases. Furthermore, when the bellows part returns to its original shape after filling with the hydraulic fluid, a buckling point jump phenomenon occurs, so-called jump buckling occurs, and deformation due to buckling concentrates at any corner. There was a fear. For this reason, it becomes difficult for the bellows part to return to the original shape after filling the working fluid, and the operator may have to manually return the shape of the diaphragm after filling the working fluid.

  Therefore, an object of the present invention is to provide a reservoir tank of a hydraulic master cylinder that can automatically return the diaphragm to its original shape after filling the hydraulic fluid while evacuating the hydraulic path.

  In order to achieve the above object, the reservoir tank of the hydraulic master cylinder of the present invention is disposed at the upper part of the cylinder hole of the hydraulic master cylinder, and the horizontal cross section communicating with the cylinder hole via the port has a rectangular shape. A reservoir body, and a cap attached to the upper opening edge of the reservoir body via a diaphragm, the diaphragm having a rectangular outer shape corresponding to the shape of the upper opening edge of the reservoir body, A flange portion at the outer end placed on the upper opening edge, a bellows portion provided inside the flange portion, and a flat portion extending inside the lower end of the bellows portion and following a change in the liquid level of the working fluid In the reservoir tank of the hydraulic master cylinder provided with the accordion portion, the bellows portion is formed in a concavo-convex shape in which a concave portion and a convex portion are continuously provided, and the convex portion is formed on a long side of the flange portion. A long side portion formed on the side, a short side portion formed inside the short side of the flange portion, and a corner portion where the short side portion and the long side portion intersect, the long side portion being The outer side surface and the inner side surface are formed in parallel with the long side of the flange portion, the corner portion is formed with the outer side surface protruding in the direction of the extension of the long side portion, and the short side portion is The side surface is formed in parallel with the short side of the flange portion, and the outer surface is formed in a curved shape gradually approaching the inner surface from the corner portion toward the central portion.

  According to the reservoir tank of the hydraulic master cylinder of the present invention, the diaphragm is deformed at the corner because the rigidity of the bellows is low at the corner and gradually increases from the corner toward the center of the short side. It is easy to do, and has a structure that is difficult to be gradually deformed from the corner portion toward the central portion of the short side portion. As a result, when the hydraulic path is evacuated when the hydraulic fluid is filled, the diaphragm is pulled toward the bottom of the reservoir tank, and the corner of the bellows extends to buckle and folds. When the bellows part returns to its original shape after filling the liquid, the central part side of the short side part with high rigidity suppresses the occurrence of jumping phenomenon of the buckling point, and the bellows part from the corner part with low rigidity. Since it returns to its original shape, it is possible to prevent deformation due to buckling from concentrating on any corner, and the diaphragm can be automatically returned to its original shape after filling with hydraulic fluid.

It is II sectional drawing of FIG. It is a top view of a hydraulic master cylinder device showing an example of the present invention. It is a top view of a diaphragm similarly. It is IV-IV sectional drawing of FIG. It is a plane side perspective view of a diaphragm showing the example of the 1st form of the present invention. It is a back side perspective view of a diaphragm similarly. It is explanatory drawing of a diaphragm at the time of evacuating a hydraulic path.

  1 to 7 show an example of a reservoir tank of a hydraulic master cylinder according to the present invention. A hydraulic master cylinder is disposed on the right side of a handle bar 1 that steers a front wheel at the front of a vehicle body of a bar handle vehicle. A hydraulic master cylinder device 4 for front brake, which is a combination of 2 and the operation lever 3, is attached. In the hydraulic master cylinder 2, a reservoir tank 5 is integrally attached to an upper portion of a cylinder body 2a disposed substantially along the handle bar 1, and a bottomed cylinder hole 2b provided by opening one end of the cylinder body 2a. The piston 2c is inserted in a fluid-tight and movable manner, and the piston 2c is pushed toward the bottom of the cylinder hole 2b by a gripping operation of the operation lever 3, so that the hydraulic pressure provided at the bottom of the cylinder hole 2b A hydraulic pressure is generated in the chamber 6.

  The reservoir tank 5 moves the diaphragm plate 8 and the diaphragm 9 up and down between a reservoir body 5b having a liquid storage chamber 5a for storing hydraulic fluid and a cap 7 covering the upper opening edge 5c of the reservoir body 5b. Two set screws 10 which are superposed and inserted through the cap 7, the diaphragm plate 8 and the diaphragm 9 are screwed onto the upper surface of the reservoir body 5b, and these are integrally attached to the reservoir body 5b.

  The cylinder body 2a and the reservoir body 5b are integrally formed of cast iron, aluminum alloy or the like, and the cylinder hole 2b and the liquid storage chamber 5a are communicated with each other through the relief port 11 and the supply port 12 (port of the present invention). Thus, the hydraulic fluid in the liquid storage chamber 5a is supplied to the cylinder hole 2b as needed, or a part of the hydraulic fluid in the cylinder hole 2b is returned to the liquid storage chamber 5a.

  The reservoir body 5b is formed in a quadrangular shape whose horizontal cross section is long in the axial direction of the handle bar 1, and a boss portion 5d that protrudes inward is provided at the center of the inner wall on the short side. Further, female screw holes 5e for attaching the caps are provided on the upper surface.

  The cap 7, the diaphragm plate 8, and the diaphragm 9 are formed in a rectangular shape in plan view that is long in the axial direction of the handle bar 1 and has substantially the same shape as the upper opening edge 5c of the reservoir body 5b. The cap 7 is formed with a screw insertion hole 7a with a tapered facing surface at the same position as each female screw hole 5e of the reservoir body 5b. The diaphragm plate 8 has a vent hole 8a in the center, and screw insertion holes 8c through which the set screws 10 are inserted are formed at positions corresponding to the female screw holes 5e formed in the reservoir body 5b of the outer edge portion 8b.

  The diaphragm 9 has a rectangular outer shape corresponding to the shape of the upper opening edge 5c of the reservoir body 5b, and is provided on the inner side of the flange portion 9a at the outer end placed on the upper opening edge 5c. Provided in the lower end of the bellows portion 9b, and a flat portion 9c that follows the change in the liquid level of the working fluid, and a position corresponding to each female screw hole 5e of the reservoir body 5b of the flange portion 9a. Are respectively formed with screw insertion holes 9d.

  The bellows portion 9b is formed in a concavo-convex shape in which a concave portion 9e and a convex portion 9f are continuously provided, a concave portion 9e is provided on the outer side, and a convex portion 9f is provided on the inner side. 9 f of convex parts are the long side part 9g formed inside the long side of the flange part 9a, the short side part 9h formed inside the short side of the flange part 9a, the short side part 9h, and the long side part The corner portion 9i intersects with 9g. The long side portion 9g is formed such that the outer side surface 9j and the inner side surface 9k are parallel to the long side of the flange portion 9a, and the corner portion 9i is formed such that the outer side surface 9j protrudes in the extension line direction of the long side portion 9g. Has been. Further, the short side portion 9h is formed in a curved shape in which the inner side surface 9k is formed in parallel with the short side of the flange portion 9a, and the outer side surface 9j gradually approaches the inner side surface 9k from the corner portion 9i toward the central portion. Has been. Accordingly, the rigidity of the bellows portion 9b is low at the corner portion 9i and gradually increases from the corner portion 9i toward the central portion of the short side portion 9h. Therefore, the corner portion 9i is easily deformed, and the short side portion from the corner portion 9i. It is formed so as not to be gradually deformed toward the central portion of the portion 9h.

  The cap 7, the diaphragm plate 8 and the diaphragm 9 are stacked one above the other so that the screw insertion hole 7a of the cap 7, the screw insertion hole 8b of the diaphragm plate 8, and the screw insertion hole 9d of the diaphragm 9 are coaxially arranged. The cap 7 is inserted by inserting the set screw 10 from above, screwing the male screw portion of the set screw 10 into the female screw hole 5e, and bringing the head of the set screw 10 into contact with the facing surface of the cap 7. The diaphragm plate 8 and the diaphragm 9 are integrally attached to the upper opening edge 5c of the reservoir body 5b.

  In the hydraulic master cylinder 2 formed in this way, when the hydraulic path is evacuated when the hydraulic fluid is filled, the diaphragm 9 is pulled to the bottom side of the reservoir tank 5 and the bellows portion 9b extends to buckle and fold. Even if it occurs, when the bellows part 9b returns to its original shape after filling with the hydraulic fluid, it is possible to suppress the occurrence of the buckling point jumping phenomenon by the central part side of the short side part 9h having high rigidity. The bellows part can return to the original shape from the corner part side having low rigidity. As a result, it is possible to prevent the deformation due to buckling from concentrating on any of the corners 9i, the bellows part 9b returns to its original shape satisfactorily after filling with the hydraulic fluid, and the diaphragm 9 automatically returns to its original form. Therefore, the workability at the time of filling the hydraulic fluid can be improved.

  Note that the present invention is not limited to the above-described embodiments, and the hydraulic master cylinder may be a tandem type, and a separate reservoir tank is provided on the top of the cylinder body, or the reservoir body is formed of resin. Things can be used. The reservoir tank may not be provided with a diaphragm plate.

DESCRIPTION OF SYMBOLS 1 ... Handlebar, 2 ... Hydraulic master cylinder, 2a ... Cylinder body, 2b ... Cylinder hole, 2c ... Piston, 3 ... Operation lever, 4 ... Hydraulic master cylinder apparatus, 5 ... Reservoir tank, 5a ... Liquid storage chamber, 5b ... reservoir body, 5c ... upper opening edge, 5d ... boss portion, 5e ... female screw hole, 6 ... hydraulic pressure chamber, 7 ... cap, 7a ... screw insertion hole, 8 ... diaphragm plate, 8a ... ventilation hole, 8b ... outer edge Part, 8c ... screw insertion hole, 9 ... diaphragm, 9a ... flange part, 9b ... bellows part, 9c ... flat part, 9d ... screw insertion hole, 9e ... concave part, 9f ... convex part, 9g ... long side part, 9h: Short side portion, 9i: Corner portion, 9j ... Outer side surface, 9k ... Inner side surface, 10 ... Set screw, 11 ... Relief port, 12 ... Supply port

Claims (1)

The reservoir body is disposed at the upper part of the cylinder hole of the hydraulic master cylinder and communicates with the cylinder hole through a port. The reservoir body has a rectangular shape, and is attached to the upper opening edge of the reservoir body via a diaphragm. And a cap
The diaphragm has a rectangular outer shape corresponding to the shape of the upper opening edge of the reservoir body, and has an outer flange portion placed on the upper opening edge and a bellows portion provided inside the flange portion. And a reservoir tank of a hydraulic master cylinder provided with a flat surface portion that extends inside the lower end of the bellows portion and follows a change in the liquid level of the hydraulic fluid,
The bellows part is formed in a concavo-convex shape in which a concave part and a convex part are continuously provided, and the convex part includes a long side part formed inside a long side of the flange part, and the flange part A short side formed inside the short side, and a corner where the short side and the long side intersect,
The long side portion is formed such that the outer side surface and the inner side surface are parallel to the long side of the flange portion, respectively.
The corner portion is formed such that an outer surface protrudes in an extension line direction of the long side portion,
The short side portion has an inner surface formed in parallel with the short side of the flange portion, and an outer surface formed in a curved shape gradually approaching the inner surface from the corner portion toward the central portion. Reservoir tank of hydraulic master cylinder.

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