TWI632080B - Master pump and reservoir - Google Patents

Abstract

The invention provides a master cylinder and a liquid storage cylinder capable of suppressing leakage of brake fluid.

The invention has a liquid storage tank wall part, a cover part (161) and a diaphragm. The liquid storage tank wall part is formed around a storage room where brake fluid can be stored, and an opening is formed on the upper part, and the outside bears the atmosphere while the vehicle is walking. The cover (161) covers the opening of the wall of the reservoir, and the diaphragm divides the storage chamber into a liquid chamber and an air chamber. An air passage is provided in the cover (161) or the wall of the reservoir ( 251, 271), and the air passage (251, 271) has openings (253, 273) that open to the outside on the side of the vehicle's forward direction, and passes through the storage compartment around the openings (253, 273). Location, connected to the air chamber.

Description

Master cylinder and reservoir

The present invention relates to a master cylinder and a liquid reservoir for a vehicle.

There is a master pump which is structured by arranging a diaphragm between a reservoir tank and a cover covering an opening above the reservoir, and using the diaphragm to divide the inside of the reservoir tank into upper and lower parts (for example, refer to patent documents 1).

[Advanced technical literature] [Patent Literature]

Patent Document 1: Japanese Patent Application Laid-Open No. 61-41660

In the above-mentioned master cylinder, the brake fluid may leak due to the air flow while the vehicle is running.

Therefore, an object of the present invention is to provide a master cylinder and a liquid reservoir which can suppress the leakage of brake fluid.

In order to achieve the above object, the present invention has a structure in which a cover portion or a wall portion of a reservoir is provided with an opening portion that opens outward on the side of the vehicle in the direction of travel and passes through the storage compartment around the opening portion. The separated location is connected to the air passage of the air chamber.

According to the present invention, it is possible to provide a master cylinder and a reservoir that can suppress the leakage of brake fluid.

10‧‧‧ reservoir

11‧‧‧master cylinder

24‧‧‧Brake lever

35‧‧‧Hydraulic cylinder

36‧‧‧Reservoir wall

38‧‧‧Storage room

59‧‧‧Brake cylinder

76‧‧‧ Pistons

161, 161A, 161B‧‧‧ Cover

163‧‧‧diaphragm

231‧‧‧Liquid chamber

232‧‧‧Air chamber

251, 251A, 251B, 271, 271A, 271B‧‧‧ atmospheric passage

253, 273‧‧‧ External opening (opening)

FIG. 1 is a plan view showing a first embodiment of the present invention.

Fig. 2 is a sectional view showing a first embodiment of the present invention.

Fig. 3 is a sectional view showing a first embodiment of the present invention.

Fig. 4 is an exploded perspective view showing a part of the first embodiment of the present invention.

Fig. 5 is a rear view showing a lid portion according to the first embodiment of the present invention.

Fig. 6 is a rear view showing a lid portion according to a second embodiment of the present invention.

Fig. 7 is a rear view showing a cover portion according to a third embodiment of the present invention.

Fig. 8 is a partial cross-sectional view showing a fourth embodiment of the present invention.

"First Embodiment"

A first embodiment of the present invention will be described with reference to Figs. 1 to 5. The first embodiment, as shown in FIG. 1, is a cylinder-integrated master cylinder 11 in which “the reservoir 10 constitutes a part of the master cylinder 11”. The master cylinder 11 is installed on a saddle-type vehicle such as a locomotive, a three-wheel buggy, or a four-wheel buggy in a state exposed to the outside. In this article, the description is made using "the state that the master cylinder 11 containing the reservoir 10 is installed in the vehicle". In the description, the front, rear, left, and right of the vehicle are used as the front, respectively. , Back, left, and right directions. The first embodiment is a master cylinder 11 for front wheel braking, which is operated by the driver's right hand. The present invention is also applicable to a master cylinder for rear wheel braking or a clutch master cylinder operated by a driver's left hand. In this case, it is opposite to the left and right (direction) in the following description.

The master cylinder 11 is a device that is disposed in a position where the walking wind (or driving wind) can be directly contacted in the vehicle. More specifically, it is installed on the right side of the steering bar 15 of the vehicle.部 的 位置 的 连接 部 16。 The location of the mounting portion 16. The steering rod 15 is formed by subjecting a cylindrical pipe member to an appropriate bending process. The outer peripheral surface of the mounting portion 16 is a cylindrical surface.

The master cylinder 11 includes a metal body member 21, a socket 22, a locking member 23, a brake lever 24, and a support member 25, all of which are made of metal. The main body member 21 is an integrally molded product by casting, and is disposed on the front side of the mounting portion 16 of the steering rod 15. The main body member 21 is provided with a mounting seat portion 30 "protruding rearwardly" on a right side portion thereof. The main body member 21 is mounted on the steering rod 15 by sandwiching the mounting portion 16 of the steering rod 15 with the mounting seat portion 30 and the socket 22. The mounting seat portion 30 and the socket 22 are coupled by a locking member 23 which is a bolt itself, and further the steering rod 15 is sandwiched. In FIG. 1, only one locking member 23 is shown because it is shown in a plan view, but the locking member 23 is provided in two up and down directions.

In the main body member 21, a pull rod support portion 31 protruding forward is formed at a lower portion of a right side portion thereof. The brake lever 24 is attached to the lever support portion 31 using a support member 25 formed of a bolt. The support member 25 is attached to the lever support portion 31 along the up-down direction, and the brake lever 24 is rotated about the support member 25 as a center. The brake lever 24 extends to the right along the steering rod 15 in front of the steering rod 15. On the main body member 21, a mirror mounting portion 32 is formed on the upper side of the tie rod support portion 31, that is, on the upper side of the right side portion.

The body member 21 is provided with a hydraulic cylinder 35 extending from the base end side of the mounting seat portion 30 to the left. The hydraulic cylinder 35 is arranged in front of the steering rod 15 in the axial direction of the mounting portion 16. This hydraulic cylinder 35 is formed in the lower part of the main body member 21 as shown in FIG. A reservoir wall portion 36 is formed in the upper portion of the cylinder 35. The liquid-reservoir wall portion 36 is formed in a cylindrical shape along the vertical direction, and forms a storage chamber 38 for "brake fluid storage" with "the liquid-reservoir bottom 37 for closing the hydraulic cylinder 35 side". The reservoir bottom 37 contains a part of the hydraulic cylinder 35.

The hydraulic cylinder 35 has a bottomed cylindrical shape in which a hydraulic cylinder hole 45 opened toward the tie rod support portion 31 side is formed. The cylinder hole 45 is along the axial direction of the mounting portion 16 of the steering rod 15 shown in FIG. 1. As shown in FIG. 2, the hydraulic cylinder hole 45 has a main hole portion 51, a fitting hole portion 53, and an inlet / outlet hole portion in this order from the hydraulic cylinder bottom portion 46 side on the opposite side to the tie rod support portion 31. Foremost edge portion of the hole) 54. The central axis of the cylinder hole 45 becomes the axis of the hydraulic cylinder 35. Hereinafter, the axial direction of the hydraulic cylinder 35 is referred to as a hydraulic cylinder axis direction.

The main hole portion 51 has the longest axial length in the cylinder hole 45. The fitting hole portion 53 is formed on the opposite side to the hydraulic cylinder bottom portion 46 of the main hole portion 51, that is, on the right side, and has a larger inner diameter than the main hole portion 51. The entrance / exit hole portion 54 is formed on the opposite side to the cylinder bottom portion 46 of the fitting hole portion 53, and is arranged in the cylinder hole 45 on the most opposite side to the cylinder bottom portion 46. The entrance and exit hole portion 54 is formed: the hole diameter is larger than the main hole portion 51 but slightly smaller than the fitting hole portion 53.

In the hydraulic cylinder bottom portion 46, a threaded hole portion 55 is formed to penetrate through the hydraulic cylinder bottom portion 46. The maximum inner diameter of the screw hole portion 55 is smaller than the inner diameter of the main hole portion 51. A socket of the brake pipe 58 indicated by a two-point lock line in FIG. 2 is locked to the threaded hole portion 55. The brake pipe 58 is connected to a brake cylinder of a brake device such as a disc brake provided on the wheel side. 59.

The reservoir bottom portion 37 is formed with a communication hole 63 and a communication hole 64 that "connect the hydraulic cylinder hole 45 and the storage chamber 38". Compared with the communication hole 64, the communication hole 63 is disposed on the side of the hydraulic cylinder bottom 46 that is more toward the direction of the cylinder axis, that is, on the left side. The communication hole 63 includes a large-aperture portion 65 disposed on the storage chamber 38 side, and a small-aperture portion 66 having a small aperture disposed on the cylinder hole 45 side. The communication hole 63 opens toward the storage chamber 38 in the large-aperture portion 65 and opens in the cylinder hole 45 in the small-aperture portion 66. The communication hole 64 includes a large-aperture portion 68 disposed on the storage chamber 38 side, and a small-aperture portion 69 having a small aperture disposed on the cylinder hole 45 side. The communication hole 64 opens toward the storage chamber 38 in the large-aperture portion 68 and opens in the cylinder hole 45 in the small-aperture portion 69. The small-aperture portion 69 of the communication hole 64 is a small-aperture portion 66 that is larger than the communication hole 63.

The master cylinder 11 includes a return spring 75, a piston 76, a cup seal 77, an O-ring 78, a fixed ring 79, a dust cover 80, and a pressing spring 81. These components are all arranged in the above-mentioned hydraulic cylinder hole 45. The return spring 75, the piston 76, the fixing ring 79, and the pressing spring 81 are made of metal, and the cup seal 77, the O-ring 78, and the dust cover 80 are formed of an elastic material such as rubber.

The piston 76 includes a shaft portion 85, a flange portion 86, a shaft portion 87, a flange portion 88, a shaft portion 89, a shaft portion 90, a shaft portion 91, a flange portion 92, a shaft portion 93, a shaft portion 94, and a shaft portion 95. , The shaft portion 96 and the flange portion 97. The piston 76 is inserted into the inlet / outlet hole portion 54 side of the cylinder hole 45.

The shaft portion 85 is formed in the piston 76 closest to the hydraulic cylinder. The bottom 46 side, that is, the left side. The flange portion 86 is disposed on the opposite side from the cylinder bottom portion 46 of the shaft portion 85, that is, on the right side, and has a larger outer diameter than the shaft portion 85. The shaft portion 87 is disposed on the opposite side to the cylinder bottom portion 46 of the flange portion 86 and has a smaller outer diameter than the shaft portion 85. The flange portion 88 is disposed on the opposite side to the cylinder bottom portion 46 of the shaft portion 87 and has a larger outer diameter than the flange portion 86. The shaft portion 89 is disposed on the opposite side to the cylinder bottom portion 46 of the flange portion 88 and has a smaller outer diameter than the flange portion 88. The shaft portion 90 is disposed on the opposite side to the cylinder bottom portion 46 of the shaft portion 89 and has the same outer diameter as the flange portion 88. The shaft portion 91 is disposed on the opposite side to the cylinder bottom portion 46 of the shaft portion 90 and has a smaller outer diameter than the shaft portion 90.

The flange portion 92 is disposed on the opposite side to the cylinder bottom portion 46 of the shaft portion 91 and has the same outer diameter as the shaft portion 90. The shaft portion 93 is disposed on the opposite side to the cylinder bottom portion 46 of the flange portion 92 and has a smaller outer diameter than the flange portion 92. The shaft portion 94 is disposed on the opposite side to the cylinder bottom portion 46 of the shaft portion 93 and has a smaller outer diameter than the shaft portion 93. The shaft portion 95 is disposed on the opposite side to the hydraulic cylinder bottom portion 46 of the shaft portion 94 and has a larger outer diameter than the shaft portion 94. The shaft portion 96 is disposed on the opposite side to the hydraulic cylinder bottom portion 46 of the shaft portion 95 and has a smaller outer diameter than the shaft portion 95. The flange portion 97 is disposed on the opposite side to the cylinder bottom portion 46 of the shaft portion 96 and has a larger outer diameter than the shaft portion 96. The flange portion 97 is formed on the opposite side of the piston 76 from the hydraulic cylinder bottom portion 46. The piston 76 is a main part slidably fitted to the cylinder hole 45 in the flange portion 88, the shaft portion 90, and the flange portion 92. 孔 部 51。 The hole portion 51. In this way, the piston 76 is provided in the hydraulic cylinder 35 so as to be slidable and moves in the direction of the hydraulic cylinder axis.

The return spring 75 is a conical coil spring having a larger diameter at one end side than the other end side in the axial direction. The end portion on the large diameter side abuts on the hydraulic cylinder bottom 46 and the end portion on the small diameter side abuts on The flange portion 86 and the shaft portion 85 of the piston 76 penetrate the inside.

The cup-shaped seal 77 is formed in a shape of a cross section including a central axis, and is a C-shaped opening to one side. The cup seal 77 is disposed between the flange portions 86 and 88 of the piston 76 and is fitted to the shaft portion 87. The cup seal 77 is in a state of "the opening side is disposed on the flange portion 86 side", and the outer peripheral portion thereof is in sliding contact with the inner peripheral surface of the main hole portion 51.

The O-ring 78 is disposed between the shaft portion 90 and the flange portion 92 of the piston 76, and is fitted to the shaft portion 91. The O-ring 78 is slidably connected to the inner peripheral surface of the main hole portion 51. The fixing ring 79 is formed in a C-shape, and is fitted and fixed to the fitting hole portion 53. A plurality of locking piece portions (not shown in the drawing extending radially inward) of the fixing ring 79 are formed at intervals in the circumferential direction, and these locking piece portions form flange portions 92 that can abut the piston 76. End surface on the shaft portion 93 side. In this way, the fixing ring 79 can restrict the "piston 76 pressed by the return spring 75" from being pulled out from the cylinder hole 45. The dust cover 80 is formed in a cylindrical shape, and one end portion thereof is disposed between the shaft portion 95 and the flange portion 97 of the piston 76, and is fitted to the shaft portion 96. The dust cover 80 extends in the entrance hole portion 54 such that the other end side thereof is positioned on the fitting hole portion 53 side, and the other end portion is pressed against the inner peripheral surface of the entrance hole portion 54 by the pressing spring 81.

In the cylinder hole 45, it is more oriented than the O-ring 78 of the piston 76. The bottom 46 side of the hydraulic cylinder is filled with brake fluid, and a cup seal 77 is formed on the side of the piston 76 and the threaded hole portion 55 of the main hole portion 51. Hydraulic chamber 101 ″.

A pressing portion 102 of a brake lever 24 is disposed on the opposite side of the cylinder bottom portion 46 of the flange portion 97 of the piston 76. Once the brake lever 24 is operated, the pressing portion 102 is moved toward the bottom 46 side of the hydraulic cylinder, that is, the finger is moved to the left, and the piston 76 is pressed in this direction. In this case, “the piston 76 and the cup seal 77 are integrally moved in the direction of reducing the hydraulic pressure chamber 101”. In this way, the brake fluid is supplied to the brake cylinder pump 59 from the hydraulic pressure chamber 101 through the brake pipe 58. In other words, by operating the brake lever 24, the piston 76 is advanced in the direction of the hydraulic cylinder bottom 46 to generate the brake hydraulic pressure. In addition, once the operation of the brake lever 24 is released, the piston 76 is restored (reset) by the elastic force of the return spring 75, and the brake fluid of the brake cylinder 59 is returned to the hydraulic chamber 101. Herein, once the amount of the brake friction material of the brake device is reduced, the volume of the hydraulic chamber on the side of the brake sub-pump 59 will be increased. In the master cylinder 11, when the brake lever 24 is not in the operating state, the hydraulic pressure chamber 101 is communicated with the storage chamber 38 through the communication hole 63. Therefore, the brake fluid of this portion (amount) is supplied from the storage chamber 38 to the hydraulic pressure chamber 101.

The reservoir wall portion 36 is formed by being disposed on the hydraulic cylinder bottom portion 46 side, that is, a side wall portion 111 disposed on the left side, and a front wall portion 112 disposed on the front side, with respect to the hydraulic cylinder bottom portion 46. , Arranged on the opposite side, that is, the side wall portion 113 arranged on the right side; and The rear wall portion 114 shown in FIG. 3 is arranged on the rear side; and the corner wall portion 115 between the front wall portion 112 and the side wall portion 113 is shown in FIG. 4; and between the side wall portion 111 and the rear wall portion 114的 角 墙 部 116。 The corner wall portion 116. The reservoir wall portion 36 is formed in a rectangular tube shape. The reservoir wall portion 36 is formed by the side wall portion 111, the front wall portion 112, the corner wall portion 115, the side wall portion 113, the rear wall portion 114, and the corner wall portion 116 surrounding the storage chamber 38, and an opening is formed in the upper portion.

As shown in FIG. 3, in the front wall portion 112, a convex portion 118 protruding forward is formed at an intermediate position in the vertical direction, and a window hole 119 is formed through the center of the convex portion 118. The window hole 119 has a large-aperture portion 120 on the front side, and a small-aperture portion 121 having a smaller diameter on the rear side than the large-aperture portion. The master cylinder 11 includes a window member 122 and a sealing member 123 attached to the window hole 119 of the main body member 21. The window member 122 is formed of a light-transmitting material and is fixed to the large-aperture portion 120 through a ring-shaped sealing member 123. Through this window member 122, the liquid level of the brake fluid in the storage chamber 38 located in the reservoir wall portion 36 can be seen.

On the outer side of the upper end portion of the reservoir wall portion 36, a protruding end edge portion 131 protruding more outward than the lower portion is formed in a ring shape over the entire circumference. In addition, a stepped gap portion 141 is formed thinner than the lower portion on the inside of the upper portion of the reservoir wall portion 36, and is formed in a ring shape over the entire circumference.

As shown in FIG. 4, the corner wall portion 115 is formed to protrude more inwardly (the storage room 38 side) than the front wall portion 112 and the side wall portion 113, and the corner wall portion 116 is formed to be more side wall portion 111 and the rear wall. The shape in which the portion 114 projects more inward. A threaded hole 148 is formed in the upper portion of the corner wall portion 115, and a threaded hole 149 is formed in the upper portion of the corner wall portion 116.

The upper end surface 151 of the side wall portion 111 of the reservoir wall portion 36 is connected to the upper end surface 152 of the front wall portion 112, the upper end surface 152 is connected to the upper end surface 155 of the corner wall portion 115, and the upper end surface 155 is connected to the upper end surface 155 of the side wall portion 113. The upper end surface 153 is connected. In addition, the upper end surface 153 is connected to the upper end surface 154 of the rear wall portion 114, the upper end surface 154 is connected to the upper end surface 156 of the corner wall portion 116, and the upper end surface 156 is connected to the upper end surface 151. These upper end surfaces 151 to 156 all form a flat surface and are arranged in the same plane. These upper end surfaces 151 to 156 constitute a frame-shaped end surface 157 having a rectangular frame shape as a whole. Similar to the corner wall portions 115 and 116, the upper end surface 155 has a shape protruding more toward these inner corners than the upper end surfaces 152 and 153, and the upper end surface 156 has a shape protruding more toward these inner corners than the upper end faces 151 and 154.

The master cylinder 11 includes a metal cover 161, metal cover mounting members 162 and 162, and a diaphragm 163 made of a rubber elastic material such as EPDM (ethylene propylene diene Monomer). .

The diaphragm 163 has a placing plate portion 171 placed on the end surface 151 above the side wall portion 111, a placing plate portion 172 placed on the end surface 152 above the front wall portion 112, and a side wall portion 113 is a mounting plate portion 173 on the upper end surface 153. In addition, the diaphragm 163 has a mounting plate portion 174 placed on the end surface 154 above the rear wall portion 114, a placing plate portion 175 placed on the end surface 155 above the corner wall portion 115, and a placement A plate portion 176 is placed on the end surface 156 above the corner wall portion 116. The placing plate portion 171 is connected to the placing plate portion 172, the placing plate portion 172 is connected to the placing plate portion 175, and the placing plate portion 175 is connected to the placing plate portion 173. The mounting plate portion 173 and the mounting plate The placement plate portion 174 is connected, the placement plate portion 174 is connected to the placement plate portion 176, and the placement plate portion 176 is connected to the placement plate portion 171.

These mounting plate portions 171 to 176 all form a flat surface and are arranged in the same plane. These mounting plate portions 171 to 176 constitute a frame-shaped plate portion 177 having a rectangular frame shape as a whole. Similar to the upper end surface 155 of the corner wall portion 115, the placing plate portion 175 has a shape protruding toward these inner corners than the placing plate portions 172 and 173, and is the same as the upper end surface 156 of the corner wall portion 116. The placing plate portion 176 The shape which protrudes toward these inside corners rather than the mounting plate part 171 and 174 is formed. The mounting plate portion 175 is formed with an insertion hole 178 penetrating the plate thickness direction, and the mounting plate portion 176 is formed with an insertion hole 179 penetrating the plate thickness direction.

As shown in FIG. 3, the diaphragm 163 has a cylindrical outer cylindrical portion 181 extending downward from an inner peripheral end edge portion of the frame plate portion 177, and a cylindrical outer portion 181 extending inward from a lower end edge portion of the outer cylindrical portion 181. A frame-like outer lower plate portion 182; and a cylindrical intermediate cylindrical portion 183 extending upward from an inner peripheral end edge portion of the outer lower plate portion 182; and a frame-like shape extending inward from an upper end edge portion of the intermediate cylindrical portion 183 An upper cylindrical portion 184; a cylindrical inner cylindrical portion 185 extending downward from an inner peripheral end edge portion of the upper plate portion 184; and an inner cylindrical shape extending from the lower end edge portion of the inner cylindrical portion 185 toward the inside and closing the inner cylindrical shape The plate-shaped inner lower plate 186 of the portion 185. These outer cylindrical portion 181, outer lower plate portion 182, middle cylindrical portion 183, upper plate portion 184, inner cylindrical portion 185, and inner lower plate portion 186 are arranged in the storage chamber 38.

The lid portion 161 is an integrally formed product formed by casting, and covers the upper opening of the reservoir wall portion 36, and the back side and the reservoir wall The frame-shaped end surface 157 of the portion 36 sandwiches the frame-shaped plate portion 177 of the diaphragm 163. In other words, the diaphragm 163 is directly sandwiched by the reservoir wall portion 36 and the cover portion 161 of the body member 21. As shown in FIG. 4, the cover portion 161 includes a main plate portion 190 that covers an opening above the reservoir wall portion 36. In the main plate portion 190, the left side edge portion 191 is connected to the front side edge portion 192, the front edge portion 192 is connected to the right side edge portion 193, the side edge portion 193 is connected to the rear side edge portion 194, and the rear edge portion 194 is connected to the side edge portion 191.

These side edge portion 191, front edge portion 192, side edge portion 193, and rear edge portion 194 constitute a frame-shaped edge portion 195 having a rectangular frame shape as a whole. The outer end surface of the front edge portion 192 and the outer end surface of the rear edge portion 194 are formed in a plane shape parallel to each other, and the outer end surface of the side edge portion 191 and the outer end surface of the side edge portion 193 are formed to be "convex toward each other". Mirror-symmetric curved shape. The outer peripheral end surface of the frame-shaped edge portion 195 is formed to have a shape larger than the “outer peripheral end edge portion of the frame-shaped end surface 157 of the reservoir wall portion 36”, and is formed into a frame-shaped plate larger than the diaphragm 163. The shape of the outer peripheral end surface of the portion 177 is two circles (two sizes larger). The cover portion 161, a corner portion between the front edge portion 192 of the main plate portion 190 and the right side edge portion 193, is fixed to the reservoir wall portion 36 by a cover portion mounting member 162 formed by a screw, and the main plate portion A corner portion between the rear edge portion 194 of the 190 and the left side edge portion 191 is fixed to the reservoir wall portion 36 by a cover portion mounting member 162 formed by a screw.

In the main plate portion 190, an insertion hole 198 through which the cover portion mounting member 162 can be inserted is formed at a corner portion between the front edge portion 192 and the side edge portion 193, and between the rear edge portion 194 and the side edge portion 191 Corners of the An insertion hole 199 through which the cover mounting member 162 is inserted. As shown in the rear view of FIG. 5, in the cover portion 161, a rectangular cylindrical protruding portion 200 protruding in a vertical direction from the rear surface is formed in a range further inside than the insertion holes 198 and 199 of the main plate portion 190. . The cylindrical protrusion 200 includes a protrusion 201 along the side edge portion 191, a protrusion 202 along the front edge portion 192, a protrusion 203 along the side edge portion 193, and a protrusion along the rear edge portion 194. 204. In addition, the cylindrical projecting portion 200 includes a projecting portion 205 that connects the projecting portion 202 and the projecting portion 203 on the insertion hole 199 side of the insertion hole 198 and a projecting portion that connects the projecting hole 198 on the insertion hole 199 side. 201 and the protruding portion 206 of the protruding portion 204. As shown in FIG. 2 and FIG. 3, the tubular protruding portion 200 is inserted between the outer tubular portion 181 and the intermediate tubular portion 183 of the diaphragm 163.

The cover portion 161 is formed with a protruding wall portion 211 protruding vertically from the back surface of the outer edge portion outside the side edge portion 191 of the main plate portion 190 with respect to the main plate portion 190 as shown in FIGS. 2 and 5; and As shown in FIG. 3 and FIG. 5, from the back surface of the outer edge portion outside the front edge portion 192 of the main plate portion 190, the protruding wall portion 212 projects vertically from the main plate portion 190. In addition, as shown in FIGS. 2 and 5, the cover portion 161 is formed with a protruding wall portion 213 that projects perpendicularly from the back surface of the outer edge portion outside the side edge portion 193 of the main plate portion 190 with respect to the main plate portion 190. And as shown in FIG. 3 and FIG. 5, from the back surface of the outer edge portion of the rear edge portion 194 of the main plate portion 190, the protruding wall portion 214 projects vertically from the main plate portion 190. As shown in FIG. 5, the protruding wall portion 211 is connected to the protruding wall portion 212, the protruding wall portion 212 is connected to the protruding wall portion 213, and the protruding wall portion 213 is connected to the protruding wall portion 214. Then, the protruding wall portion 214 is connected to the protruding wall portion 211. In this way, the protruding wall portions 211 to 214 constitute a frame-shaped wall portion 215 having a rectangular frame shape as a whole. The protruding wall portions 212 and 214 are formed in a straight line shape parallel to each other, and the protruding portions 211 and 213 are formed in a mirror-symmetrical arc shape that is “convex in opposite directions from each other”.

The main plate portion 190 is connected to the "face portion 221 between the protruding wall portion 211 and the protruding portion 201" and the "face portion 222 between the protruding wall portion 212 and the protruding portion 202", and the face portion 222 and "the protruding wall portion 212, 213 and the protruding portion The face 225 ″ between the parts 205 is connected. The face 225 is connected to the “face 223 between the protruding wall portion 213 and the protruding portion 203”, and the face 223 is connected to the “face 224 between the protruding wall portion 214 and the protruding portion 204”. The face 224 is connected to the “face 226 between the protruding wall portions 211 and 214 and the protruding portion 206”, and the face 226 is connected to the face 221. These faces 221 to 226 all form a flat surface and are arranged in the same plane. These face portions 221 to 226 constitute a frame-shaped face portion 227 having a rectangular frame shape as a whole. The face portion 221 is along the protruding wall portion 211, the face portion 222 is along the protruding wall portion 212, the face portion 223 is along the protruding wall portion 213, and the face portion 224 is along the protruding wall portion 214. The face portions 222 and 224 are formed in a straight line shape parallel to each other, and the face portions 221 and 223 are formed in an arc shape.

The face 225 is enlarged such that the width in the front-back direction is wider than the face 222 and the width in the left-right direction protrudes toward the inside corners wider than the face 223; and an insertion hole 198 is formed at a middle position of the face 225. The face 226 is enlarged so that the width in the front-back direction is wider than the face 224 and the width in the left-right direction is wider than the face 221 toward these inner corners. And an insertion hole 199 is formed at a middle position of the face 226.

As shown in FIG. 2, the frame-shaped plate portion 177 of the diaphragm 163 is sandwiched by the frame-shaped end surface 157 of the reservoir wall portion 36 and the frame-shaped surface portion 227 of the cover portion 161. That is, the placing plate portion 171 is sandwiched by the upper end surface 151 and the surface portion 221, and the placing plate portion 173 is sandwiched by the upper end surface 153 and the surface portion 223. In addition, as shown in FIG. 3, the placing plate portion 172 is sandwiched by the upper end surface 152 and the surface portion 222, and the placing plate portion 174 is sandwiched by the upper end surface 154 and the surface portion 224. In addition, the placing plate portion 175 shown in FIG. 4 is sandwiched by the upper end surface 155 and the face portion 225 shown in FIG. 5, and the placing plate portion 176 shown in FIG. 4 is surrounded by the upper end surface 156 and the first The face 226 shown in FIG. 5 is sandwiched.

In FIG. 5, the frame-shaped plate portion 177 of the diaphragm 163 is displayed with a two-point lock line with respect to the cover portion 161 shown by a solid line. In the above-mentioned sandwiched state, the outer end surface of the mounting plate portion 171 faces the inner wall surface of the protruding wall portion 211 in an abutting or approaching state, and the outer end surface of the mounting plate portion 172 is abutting or approaching The state faces the inner wall surface of the protruding wall portion 212, the outer end surface of the mounting plate portion 173 faces the inner wall surface of the protruding wall portion 213 in abutting or approaching state, and the outer end surface of the mounting plate portion 174 is abutted or The approached state faces the inner wall surface of the protruding wall portion 214. In addition, the outer end surface of the mounting plate portion 175 faces the inner wall surface of the corner portion of the protruding wall portions 212 and 213 in abutting or approaching state, and the outer end surface of the mounting plate portion 176 is in abutting or approaching state. The inner wall surfaces facing the corners of the protruding wall portions 211 and 214.

The frame-like plate portion 177 of the diaphragm 163 shown in FIG. 4 is covered by the “frame-like end surface 157 of the reservoir wall portion 36” and “the cover shown in FIG. 5”. In a state of being sandwiched by the frame-shaped face portion 227 of the portion 161, one of the cover portion mounting members 162 shown in FIG. 4 is inserted into the "insertion hole 198 formed in the cover portion 161" and "formed in the diaphragm 163". The insertion hole 178 of the mounting plate portion 175 is locked into the "screw hole 148 formed in the upper end surface 155 of the reservoir wall portion 36". In addition, the other cover part mounting member 162 is inserted into the "insertion hole 199 formed in the cover part 161" and the "insertion hole 179 formed in the mounting plate part 176 of the diaphragm 163" and is locked into the "formed in Screw holes 149 "of the upper end surface 156 of the reservoir wall portion 36. In this way, the cover portion 161 and the diaphragm 163 are attached to the body member 21. As shown in FIGS. 2 and 3, the height from the frame-shaped surface portion 227 to the protruding front end of the frame-shaped wall portion 215 is smaller than the thickness of the frame-shaped plate portion 177 of the diaphragm 163 in this mounted state. Accordingly, in this mounted state, a gap 230 is provided between the “front end surface of the lower end of the frame-shaped wall portion 215 of the cover portion 161” and the “upper end surface of the frame-shaped end surface 157 of the reservoir wall portion 36”.

The diaphragm 163 divides the storage chamber 38 into a liquid chamber 231 for storing brake fluid on the lower side and an air chamber 232 on the upper side. Thereby, it is possible to suppress the brake fluid of the fluid chamber 231 from directly contacting the outside air, and to suppress the moisture absorption of the brake fluid. In addition, the deformation of the diaphragm 163 can follow the change in the amount of brake fluid in the fluid chamber 231. The air chamber 232 communicates with the atmosphere as described later.

The reservoir wall portion 36 and the reservoir bottom portion 37 of the body member 21, the window member 122, the sealing member 123, and the diaphragm 163 shown in FIG. 3, and the cover mounting members 162 and 162 shown in FIG. It is provided in the upper part of the hydraulic cylinder 35 shown in FIG. Liquid tube 10. Accordingly, the reservoir tank 10 is integrally connected to the "master cylinder 11 that supplies brake fluid to the brake sub-cylinder 59". The master cylinder 11 is disposed in the vehicle in a position where it can directly contact the traveling wind (or called traveling wind). Therefore, the reservoir 10 receives the vehicle on the outside of the reservoir wall portion 36 and on the outside of the cover portion 161. The flow of the atmosphere during walking.

As shown in FIG. 5, two passage grooves 235 and 236 recessed in the vertical direction with respect to the frame-shaped surface portion 227 are formed in the frame-shaped surface portion 227 of the cover portion 161. The channel grooves 235 and 236 are formed during casting. The via grooves 235 and 236 can also be formed by cutting.

The via groove 235 is formed by the groove portions 241 to 247. The groove portion 241 is formed slightly toward the side edge portion 193 side from the center position in the left-right direction of the cover portion 161, and is formed from an end portion on the protruding wall portion 212 side of the surface portion 222 to an intermediate position on the protruding portion 202 side. The groove portion 241 is formed in a straight line orthogonal to the "direction in which the face portion 222 extends". The groove portion 242 extends from the end on the side of the protruding portion 202 of the groove portion 241 through the middle position in the front and back direction of the face portion 222 and extends along the extending direction of the face portion 222 toward the face portion 225 to the front position of the insertion hole 198 in the face portion 225. until. The groove portion 242 is formed in a linear shape similar to the surface portion 222.

The groove portion 243 extends from the end portion on the surface portion 225 side of the groove portion 242 through the insertion hole 198 of the surface portion 225 and the protruding portion 205 to the surface portion 223 side in the surface portion 225. The groove portion 243 is connected to the groove portion 242 and is perpendicular to the extending direction of the face portion 222. The opposite portion of the groove portion 242 is along the extending direction of the face portion 222. The portion therebetween is formed as "concentric with the insertion hole 198" Shape. " The groove portion 244 extends from the end portion of the groove portion 243 opposite to the groove portion 242 through the middle position in the left-right direction of the face portion 223 to the face portion 224 along the extending direction of the face portion 223. The groove portion 244 is formed in an arc shape similar to the surface portion 223.

The groove portion 245 extends from the end portion of the groove portion 244 opposite to the groove portion 243 through the middle position of the face portion 224 in the front-rear direction and extends along the extending direction of the face portion 224 to be slightly sideward than the center position of the cover portion 161 in the left-right direction. To the edge 193 side. The groove portion 245 is formed in a linear shape similar to the surface portion 224. The groove portion 246 is perpendicular to the extending direction of the face portion 224 from the end portion of the groove portion 245 opposite to the groove portion 244 and extends to the protruding portion 204 side. The groove portion 246 passes through the end portion of the protruding portion 204 side of the face portion 224 and penetrates in the front-rear direction. Projection 204. The groove portion 246 is arranged in the same linear shape as the groove portion 241. The groove portions 241 to 246 are arranged on the same plane as the groove bottom surface that becomes the top surface when the vehicle is mounted, and form a certain depth with respect to the frame-shaped surface portion 227.

The groove portion 247 is recessed from the end portion of the groove portion 241 opposite to the groove portion 242 on the opposite side of the protruding wall portion 212 from the inner end wall surface of the protruding wall portion 212. As shown in FIG. 3, the groove portion 247 has an opening opposite to the groove portion 241 toward the protruding front end portion of the protruding wall portion 212, and an end portion on the groove portion 241 side is formed to a groove portion 241 which is more concave than the surface portion 222. The location of the bottom surface of the trench.

The passage groove 235 is closed by the frame-shaped plate portion 177 of the diaphragm 163: from the groove portion 241 through the groove portion 242 and the groove portions 243 to 245 shown in FIG. 5 to the groove portion 245 side of the groove portion 246 shown in FIG. 3 section until. The passage groove 235 forms an atmospheric passage 251 between the passage groove 235 and the diaphragm 163. The atmospheric passage 251 communicates with the air chamber 232 through the "internal opening 252 formed by the groove portion 246 and the inner edge of the mounting plate portion 174 of the diaphragm 163". In addition, the air passage 251 faces the "projecting wall portion 212 of the cover portion 161 which becomes the outside of the reservoir 10" and the "reservoir wall portion 36" through an external opening (opening portion) 253 at the lower end of the groove portion 247. The gap 230 between the upper end surfaces 152 ″ of the opening forms an opening.

That is, the atmospheric passage 251 is formed in the cover portion 161. As shown in FIG. 1, the shape of the passage groove 235 has an external opening portion 253 that opens outward on the vehicle's forward direction side, and passes through the storage chamber 38 (see reference (Figures 2 and 3), the internal opening 252, which is offset from the external opening 253, communicates with the air chamber 232 (see Figures 2 and 3). The air passage 251 is curved with respect to the groove portion 241, the groove portion 242 is curved with respect to the groove portion 242, the groove portion 243 is curved, the groove portion 243 is curved, with respect to the groove portion 243, the groove portion 244 is curved, and the groove portion 245 is curved with respect to the groove portion 244. In the groove portion 245, the groove portion 246 is bent to form a labyrinth structure.

As shown in FIG. 5, the passage groove 236 is formed by groove portions 261 to 267. The groove portion 261 is formed slightly toward the side edge portion 191 side from the center position in the left-right direction of the cover portion 161, and is formed from an end portion on the protruding wall portion 212 side of the surface portion 222 to an intermediate position on the protruding portion 202 side. The groove portion 261 is formed in a straight line orthogonal to the "direction in which the face portion 222 extends". The groove portion 262 passes from the end portion on the protruding portion 202 side of the groove portion 261, passes through the middle position of the front and rear directions of the face portion 222, and extends along the extending direction of the face portion 222. Extends to the face 221. The groove portion 262 is formed in a straight line like the surface portion 222 and is arranged on the same straight line as the groove portion 242.

The groove portion 263 extends from the end portion of the groove portion 262 on the surface portion 221 side to the middle position in the left-right direction of the surface portion 221 and extends along the extending direction of the surface portion 221 toward the surface portion 226 to the front position of the insertion hole 199 in the surface portion 226. The groove portion 263 is formed in an arc shape similar to the surface portion 221. The groove portion 264 extends from the end portion on the surface portion 226 side of the groove portion 263 through the insertion hole 199 of the surface portion 226 and the protruding portion 206 to the surface portion 224 side of the surface portion 226. The groove portion 264 is connected to the groove portion 263 along the extending direction of the face portion 224. The opposite portion of the groove portion 263 is perpendicular to the extending direction of the face portion 224 with respect to the groove portion 263, and the portion therebetween is formed "concentrically with the insertion hole 199". Way to form a bend.

The groove portion 265 extends from the end of the groove portion 264 on the opposite side from the groove portion 263 through the middle position of the face portion 224 in the front-rear direction, and extends along the extending direction of the face portion 224 to be slightly sideward from the center position in the left-right direction of the cover portion 161 Up to the edge 191 side. The groove portion 265 is formed in a straight line like the surface portion 224 and is arranged on the same straight line as the groove portion 245. The groove portion 266 is perpendicular to the extending direction of the face portion 224 from the end portion of the groove portion 265 opposite to the groove portion 264 and extends to the protruding portion 204 side. The groove portion 266 passes through the end portion of the protruding portion 204 side of the face portion 224 and penetrates forward and backward. Projection 204. The groove portion 266 is arranged in the same linear shape as the groove portion 261. The groove portions 261 to 266 are arranged on the same plane as the bottom surface of the groove which becomes the top surface when the vehicle is mounted, and forms a certain depth with respect to the frame-shaped surface portion 227.

The groove portion 267 is recessed from the end portion of the groove portion 261 opposite to the groove portion 262 from the inner end wall surface of the protruding wall portion 212 in a direction opposite to the protruding portion 202. The groove portion 267 has an opening opposite to the groove portion 261 toward the protruding front end portion of the protruding wall portion 212, and the end portion on the groove portion 261 side is formed to the position of the groove bottom surface of the groove portion 261 which is more recessed than the surface portion 222. Here, in the above-mentioned mounted state, the frame-shaped plate portion 177 of the diaphragm 163 is elastically deformed, and the outer peripheral surface thereof contacts the entire inner peripheral wall surface except for the groove portions 247 and 267 of the frame-shaped wall portion 215.

The passage groove 236 is closed by the frame-like plate portion 177 of the diaphragm 163: from the groove portion 261 to the portion on the groove portion 265 side of the groove portion 266 through the groove portions 262 to 265. The passage groove 236 forms an atmospheric passage 271 between the passage groove 236 and the diaphragm 163. The atmospheric passage 271 communicates with the air chamber 232 shown in FIG. 3 through the “internal opening 272 formed by the groove portion 266 and the inner end edge portion of the mounting plate portion 174 of the diaphragm 163”. In addition, the atmospheric passage 271 shown in FIG. 5 faces the space between the protruding wall portion 212 and the reservoir wall portion 36 shown in FIG. 3 through an external opening portion (opening portion) 273 at the lower end of the groove portion 267. The gap 230 forms an opening.

That is, the atmospheric passage 271 is formed in the cover portion 161. As shown in FIG. 1, the shape of the passage groove 236 has an external opening portion 273 that opens outward on the vehicle's forward direction side, and passes through the storage chamber 38 (see reference (Figures 2 and 3), the internal opening 272, which is offset from the external opening 273, communicates with the air chamber 232 (refer to Figures 2 and 3). The air passage 271 is formed with respect to the groove portion 261 and the groove portion 262 Bending, the groove portion 263 is bent relative to the groove portion 262, the groove portion 264 is bent relative to the groove portion 263, the groove portion 264 is bent, the groove portion 265 is bent relative to the groove portion 264, and the groove portion 266 is bent relative to the groove portion 265, thereby becoming a maze structure.

The master cylinder 11 is larger than the atmospheric passages 251 and 271, so that the air chamber 232 shown in FIG. 2 is maintained substantially at atmospheric pressure. In this way, even if the brake friction material is reduced and the volume of the hydraulic chamber on the side of the brake cylinder 59 is increased, the "replenishment of brake fluid from the liquid chamber 231 of the storage chamber 38 to the hydraulic chamber 101" can be performed in the liquid chamber 231. Maintained at atmospheric pressure.

The master cylinder described in the above-mentioned Patent Document 1 has a structure in which the inside of the reservoir tank is divided into upper and lower parts by a diaphragm, and a passage for communicating the "chamber above the diaphragm" with external air is provided in the reservoir. The left and right sides of the liquid cartridge are open to the outside. The walking wind is formed along the left and right side surfaces of the master cylinder from the front to the rear, and the passage forms a vertical direction with respect to the flow of the walking wind. Therefore, the venturi effect caused by the flow of the atmosphere while the vehicle is walking may cause the opening of the passage to become a negative pressure. According to this, once the brake fluid has penetrated into the diaphragm over the years, for example, and reaches the air chamber side from the fluid chamber side, the brake fluid will be sucked out of the opening due to the flow of atmospheric air while the vehicle is walking, and may leak to the outside. Possible. In addition, although an additional diaphragm plate can be provided to prevent the brake fluid of the air chamber from leaking to the outside, in this case, the number of parts increases, resulting in a large increase in cost.

On the other hand, the master cylinder 11 including the above-mentioned liquid storage tank 10 communicates the air chamber 232 with the atmospheric path of the outside air (or simply outside air). 251 and 271 have external openings 253 and 273 that open outward on the vehicle's forward direction side (the upwind side of the traveling wind), and pass through the storage chamber 38 around the storage chambers that are offset from the external openings 253 and 273. The rear side of 38, that is, the internal openings 252 and 272 on the vehicle backward direction (referring to the rear of the traveling direction) side communicate with the air chamber 232. In this way, it is difficult for the external openings 253 and 273 to develop a negative pressure even if there is a flow of the atmosphere while the vehicle is traveling. Accordingly, even if the brake fluid is present on the air chamber 232 side, it is possible to suppress the brake fluid from being sucked out of the external openings 253 and 273 due to the flow of the atmosphere while the vehicle is running. Accordingly, even if no diaphragm plate is provided, the possibility of the brake fluid leaking to the outside can be reduced. In addition, since the “walking wind is introduced into the air chamber 232 from the external openings 253 and 273”, the followability of the diaphragm 163 to the brake fluid level is improved, and the supply performance of the brake fluid toward the brake sub-cylinder 59 can be improved.

In addition, since the external openings 253 and 273 are opened downward at the protruding wall portion 212 of the leading edge portion 192, the leading edge portion 192 of the main plate portion 190 serves as a shield to prevent rainwater or foreign matter from entering the air passages 251 and 271. . As a result, intrusion of rainwater, foreign matter, and the like into the air chamber 232 can be suppressed.

The air passage 251 is curved with respect to the groove portion 241, the groove portion 242 is curved with respect to the groove portion 242, the groove portion 243 is curved, the groove portion 243 is curved, with respect to the groove portion 243, the groove portion 244 is curved, and the groove portion 245 is curved with respect to the groove portion 244. In the groove portion 245, the groove portion 246 is bent to form a labyrinth structure. In addition, the air passage 271 is curved with respect to the groove portion 261, and the groove portion 262 is curved with respect to the groove portion 262. The groove portion 263 is bent. The groove portion 264 is bent with respect to the groove portion 263, the groove portion 264 is bent, the groove portion 265 is bent with respect to the groove portion 264, and the groove portion 266 is bent with respect to the groove portion 265 to form a labyrinth structure. Accordingly, the atmospheric passages 251 and 271 increase the pressure loss due to the "various curved portions of the dynamic pressure (so-called RAM pressure) generated by the walking wind", and can suppress the influence of the hydraulic pressure rise caused by the walking wind.

Here, the dynamic pressure P generated by the walking wind can be obtained from the following calculation formula.

P = 1/2 × ρ × V 2

The density ρ of the air is ρ = 1.2 kg / m ³ and V is the volume. If the minimum hydraulic pressure for the brake sub-pump 59 is set to 0.05 MPa, even in the case where there is no pressure loss due to the labyrinth structure, in the calculation On the other hand, the vehicle's walking speed starts to affect the brake sub-cylinder 59 from 350km / h. As long as it has a labyrinth structure, it can further suppress the impact of walking wind.

In the above-mentioned first embodiment, the groove portion 242 and the groove portion 262 shown in FIG. 5 may be connected and communicated with each other by “an additional groove portion disposed on the same line as the two”. Atmospheric pathways 251, 271. In addition, the grooves 245 and the grooves 265 may be separately connected to each other by “additional grooves arranged on the same line as the two” to connect the air passages 251 and 271. .

"Second Embodiment"

Next, the second embodiment is mainly based on FIG. 6 and focuses on the second embodiment. The differences between the first embodiment will be described. Parts that are common to the first embodiment are indicated by the same names and the same drawing numbers.

In the second embodiment, a lid portion 161A shown in FIG. 6 having a partly different structure is used for the lid portion 161 of the first embodiment. The cover portion 161A is formed with passage grooves 235A and 236A which are partially different from the passage grooves 235 and 236 of the first embodiment. Via grooves 235A and 236A are also formed during casting. In FIG. 6, the frame-shaped plate portion 177 of the diaphragm 163 is displayed with a two-point lock line with respect to the cover portion 161A shown by a solid line.

Via grooves 235A are formed with groove portions 241 to 243 and 247 which are the same as those in the first embodiment, groove portions 246 of the first embodiment are not formed, and groove portions 244A and 245A which are different from the first embodiment are formed.

The groove portion 244A extends from the end portion of the groove portion 243 opposite to the groove portion 242 in the face portion 225 along the extending direction of the face portion 223 to a specific position on the face portion 223 side. The groove portion 244A is formed in a linear shape along a direction perpendicular to the “projecting wall portion 212”. The groove portion 245A extends from the end portion of the groove portion 244A opposite to the groove portion 243 in the opposite direction with respect to the protruding wall portion 213 and penetrates the protruding portion 205 in the left-right direction. The groove portions 241 to 243, 244A, and 245A are arranged on the same plane as the bottom surface of the groove that becomes the top surface when the vehicle is mounted, and a certain depth is formed from the frame-shaped surface portion 227.

The channel groove 235A is formed: the groove portion 241 to 243, the groove portion 244A, and the groove portion 244A side of the groove portion 245A are closed by the same diaphragm 163 as the first embodiment, and are formed between the diaphragm 163 and the diaphragm 163. 成 Atmosphere path 251A. This atmospheric passage 251A is connected to the air chamber 232 through the "internal opening 252A formed by the groove portion 245A and the inner end edge portion of the mounting plate portion 175 of the diaphragm 163", and is opposed to the air chamber 232 through the groove portion 247 The external opening portion 253 of the opposite end portion of the groove portion 241 opens toward the outside of the liquid storage cartridge 10. That is, the atmospheric passage 251A is formed in the cover portion 161A. The shape of the passage groove 235A has an external opening portion 253 that is open to the outside on the vehicle's forward direction side, and passes around the storage chamber 38, and is deflected from the external opening portion 253. The internal opening 252A at the moved position communicates with the air chamber 232. The air passage 251A forms a labyrinth structure: the groove portion 242 is bent with respect to the groove portion 241, the groove portion 243 is bent with respect to the groove portion 242, the groove portion 243 is bent, and the groove portion 244A is bent with respect to the groove portion 243, with respect to the groove portion 244A, The groove portion 245A is bent.

The channel grooves 236A are formed with groove portions 261, 262, and 267 which are the same as those in the first embodiment, groove portions 265, 266 of the first embodiment are not formed, and groove portions 263A, 264A different from the first embodiment are formed.

The groove portion 263A extends from the end portion of the groove portion 262 opposite to the groove portion 261 through the middle position in the left-right direction of the face portion 221 to the face portion 226 along the extending direction of the face portion 221. The groove portion 263A is formed in an arc shape similar to the surface portion 221. The groove portion 264A extends from the end portion of the groove portion 263A opposite to the groove portion 262 in the opposite direction of the protruding wall portion 211 and penetrates the protruding portion 206 in the left-right direction. The groove portions 261, 262, 263A, and 264A are arranged on the same groove bottom surface that becomes the top surface when the vehicle is mounted on the vehicle. The flat surface has a certain depth from the frame-shaped surface portion 227.

The passage groove 236A is formed: the groove portion 261, 262, the groove portion 263A, and the groove portion 263A side of the groove portion 264A are closed by the diaphragm 163 similar to the first embodiment, and an air passage 271A is formed between the diaphragm 163 and the diaphragm 163. The atmospheric passage 271A communicates with the air chamber 232 through the "internal opening 272A formed by the groove portion 264A and the inner end edge portion of the mounting plate portion 176 of the diaphragm 163", and is opposed to the air chamber 232 through the groove portion 267. The external opening portion 273 of the opposite end portion of the groove portion 261 opens toward the outside of the reservoir 10. That is, the atmospheric passage 271A is formed in the cover portion 161A, and has the shape of the passage groove 236A, and has an external opening portion 273 that opens outward on the side of the vehicle's forward direction, and passes around the storage chamber 38 and is deflected from the external opening portion 273. The internal opening 272A at the moved position communicates with the air chamber 232. The air passage 271A has a labyrinth structure in which the groove portion 262 is bent with respect to the groove portion 261, the groove portion 263A is bent with respect to the groove portion 262, and the groove portion 264A is bent with respect to the groove portion 263A.

According to such a second embodiment, the labyrinth structure of the atmospheric passages 251A and 271A is simpler than that of the first embodiment. As a result, the production of the passage grooves 235A and 236A is facilitated, and the manufacturing cost can be reduced.

"Third Embodiment"

Next, the third embodiment will be described mainly with reference to FIG. 7 and focusing on differences from the first embodiment. Parts that are common to the first embodiment are indicated by the same names and the same drawing numbers.

In the third embodiment, the cover portion 161B shown in FIG. 7 having a partly different structure is used for the cover portion 161 of the first embodiment. The cover portion 161B is formed with passage grooves 235B and 236B that are different from the passage grooves 235 and 236 of the first embodiment. Via grooves 235B and 236B are also formed during casting. In FIG. 7, the frame-shaped plate portion 177 of the diaphragm 163 is displayed with a two-point lock line with respect to the cover portion 161B shown by a solid line.

The channel groove 235B is formed with groove portions 241, 242, and 247 which are the same as those of the first embodiment, groove portions 244 to 246 of the first embodiment are not formed, and groove portions 243B different from the first embodiment are formed. The groove portion 243B extends from the end portion of the groove portion 242 opposite to the groove portion 241 in the opposite direction of the protruding wall portion 212 and penetrates the protruding portion 205 in the front-rear direction. The groove portions 241, 242, and 243B are arranged on the same plane as the groove bottom surface that becomes the top surface when the vehicle is mounted, and form a certain depth from the frame-shaped surface portion 227.

The passage groove 235B is formed: portions on the groove portion 242 side of the groove portions 241 and 242 and the groove portion 243 are closed by the same diaphragm 163 as in the first embodiment, and an atmospheric passage 251B is formed between the diaphragm 163 and the diaphragm 163. The atmospheric passage 251B communicates with the air chamber 232 through the "internal opening 252B formed by the groove portion 243B and the inner end edge portion of the mounting plate portion 175 of the diaphragm 163", and is opposed to the air chamber 232 through the groove portion 247. The external opening portion 253 of the opposite end portion of the groove portion 241 opens toward the outside of the liquid storage cartridge 10. That is, the air passage 251B is formed in the cover portion 161B, and has the shape of the passage groove 235B that has an outer opening that opens outward on the side of the vehicle in the forward direction. The partial opening portion 253 communicates with the air chamber 232 through the internal opening portion 252B at a position shifted from the external opening portion 253 around the storage chamber 38. The air passage 251B has a labyrinth structure in which the groove portion 242 is bent with respect to the groove portion 241 and the groove portion 243B is bent with respect to the groove portion 242.

The channel grooves 236B are formed with the same groove portions 261 and 267 as in the first embodiment, the groove portions 264 to 266 of the first embodiment are not formed, and groove portions 262B and 263 different from the first embodiment are formed.

The groove portion 262B extends from the end portion on the protruding portion 202 side of the groove portion 261 through the middle position in the front and rear directions of the face portion 222 and extends along the extending direction of the face portion 222 toward the face portion 221 side to the front of the face portion 221. The groove portion 262B is formed in a straight line like the surface portion 222 and is arranged on the same straight line as the groove portion 242. The groove portion 263B extends from the end portion of the groove portion 262B opposite to the groove portion 261 in the opposite direction of the protruding wall portion 212 and penetrates the protruding portion 202 in the front-rear direction. The groove portions 261, 262B, and 263B are arranged on the same plane as the bottom surface of the groove that becomes the top surface when the vehicle is mounted on the vehicle, and a certain depth is formed from the frame-shaped surface portion 227.

The passage groove 236B is formed: the groove portions 261 and 262 and the groove portion 262B side of the groove portion 263B are closed by the same diaphragm 163 as in the first embodiment, and an atmospheric passage 271B is formed between the groove 261 and the diaphragm 163. The atmospheric passage 271B communicates with the air chamber 232 through the "internal opening 272B formed by the groove portion 263B and the inner end edge portion of the mounting plate portion 172 of the diaphragm 163", and is opposed to the air chamber 232 through the groove portion 267 Ditch The external opening 273 on the opposite end of 261 is opened toward the outside of the reservoir 10. That is, the atmospheric passage 271B is formed in the cover portion 161B. The shape of the passage groove 236B has an external opening portion 273 that is open to the outside on the vehicle traveling direction side, and passes around the storage chamber 38 and is biased from the external opening portion 273. The internal opening 272B at the moved position communicates with the air chamber 232. The air passage 271B has a labyrinth structure in which the groove portion 262B is curved with respect to the groove portion 261 and the groove portion 263B is curved with respect to the groove portion 262B.

According to such a third embodiment, of course, the maze structure of the atmospheric passages 251B and 271B is more concise than the first embodiment. Even if compared with the second embodiment, it is also more concise. According to this, the channel grooves 235B and 236B Production becomes easy and can reduce manufacturing costs.

"Fourth Embodiment"

A fourth embodiment of the present invention will be described with reference to Fig. 8. In the fourth embodiment, as shown in FIG. 8, a passage groove 335 is formed in the frame-shaped end surface 357 of the liquid-reservoir wall portion 336 of the main body member 321 as an atmospheric passage. In detail, one end side of the passage groove 335 is provided on the frame-shaped end surface 357, and is formed on the vehicle's forward direction side, and communicates with the groove portion 341 having the "exterior opening portion 353 opening outward". In addition, the other end side of the passage groove 335 is formed to communicate with the "opening toward the air chamber 232" from the groove portion 365 that becomes a part of the passage groove 335 through the "communication hole 301 formed in the frame-like plate portion 377 of the diaphragm 363". Groove portion 246 ″ of the cover portion 361. In this way, in the fourth embodiment, the The groove portion 341 and the passage groove 335 of the wall portion 336, the communication hole 301 formed in the diaphragm 363, and the groove portion 246 of the cover portion 361 constitute an atmospheric passage. With such a structure, in the fourth embodiment, even if the brake fluid is present on the air chamber 232 side, it is possible to suppress the brake fluid from being sucked out of the external opening 353 by the flow of the atmosphere while the vehicle is running. Accordingly, even if no diaphragm plate is provided, the possibility of the brake fluid leaking to the outside can be reduced.

As described above, in the first embodiment, the atmospheric channels 251 and 271 are formed by forming the channel grooves 235 and 236 in the cover portion 161. In the second embodiment, the channel grooves 235A and 236A are formed in the cover portion 161A. When the atmospheric passages 251A and 271A are formed, in the third embodiment, the atmospheric passages 251B and 271B are formed by forming the passage grooves 235B and 236B in the cover portion 161B. On the other hand, a channel groove having the same shape may be formed on the frame-shaped end surface 157 of the reservoir wall portion 36, and an atmospheric channel may be formed between the channel groove and the diaphragm.

The external openings of the air passage can be arranged at arbitrary positions as long as they are on the vehicle's forward direction side, and the number can be arbitrarily set. The internal openings of the air passage can be arranged at any positions as long as they are offset from the external openings, and their number can be arbitrarily set.

The present invention can also be applied to an individual that is separated from the master cylinder and connected to a reservoir of the master cylinder through a pipe.

In addition, although the cover portions 161, 161A, and 161B are formed of a metal member such as cast iron in the above embodiment, a resin member such as plastic or rubber may be used. In addition, although the cover portions 161, 161A, and 161B It is an integrally formed product formed by casting, but may be formed by sintering or the like.

The above embodiment is a master cylinder as follows: it has a hydraulic cylinder with a "piston propelled by the operation of the brake lever" provided as a slide; and it is provided on the upper part of the hydraulic cylinder for the storage of brake fluid The liquid storage tube has a liquid storage tube wall portion, a cover portion and a diaphragm. The liquid storage tube wall portion is formed around a storage chamber where the brake fluid can be stored, and an opening is formed on the upper portion to bear on the outside. The flow of the atmosphere while the vehicle is walking, the cover portion covers the opening of the liquid storage tank wall portion, and the diaphragm separates the storage chamber into a liquid chamber and an air chamber, and is provided on the cover portion or the liquid storage tank wall portion An air passage having an opening portion that is open to the outside on the vehicle's forward direction side, and communicates with the air chamber through the periphery of the storage chamber at a position offset from the opening portion.

In addition, the above embodiment is a reservoir that is connected to the "master cylinder that supplies brake fluid to the brake cylinder" and can store the brake fluid. The reservoir has a reservoir wall portion, a cover portion, and a membrane. The wall portion of the reservoir tube is formed around a storage chamber where the brake fluid can be stored, and an opening is formed on the upper portion, and the outside receives the flow of the atmosphere during vehicle running. The cover portion covers the opening of the wall portion of the reservoir tube. And the diaphragm divides the storage chamber into a liquid chamber and an air chamber, and an air passage is provided in the cover or the wall of the liquid storage cylinder, and the air passage has an opening opening to the outside on the side of the vehicle's forward direction, The periphery of the storage chamber communicates with the air chamber at a position shifted from the opening.

The atmospheric passage is between the cover portion and the liquid reservoir. The wall portions are formed by bending. The atmospheric passage communicates with the air chamber on the vehicle's rearward direction side. In addition, the atmospheric passage communicates with the air chamber on a side surface side of the vehicle. The atmospheric passage communicates with the air chamber on the side of the vehicle in the forward direction.

As described above, by providing the cover portion or the reservoir wall portion with "an opening portion that opens outward on the side of the vehicle's forward direction, and communicates at a position offset from the opening portion through the storage compartment, The atmospheric path to the air chamber makes it difficult for the opening to develop a negative pressure even if the air flows during the vehicle's travel. According to this, even if the brake fluid is present on the air chamber side, it is possible to suppress the brake fluid from being sucked out of the opening by the flow of the atmosphere while the vehicle is running.

Claims (10)

A master cylinder includes a hydraulic cylinder provided with a piston that can be slid by the operation of a brake lever; and a liquid storage cylinder provided on the upper part of the hydraulic cylinder for the storage of brake fluid. The liquid storage cylinder has: A wall portion of the liquid storage tank is formed around a storage room where the brake fluid can be stored, and an opening is formed on the upper portion, and the outside receives the flow of the atmosphere during the vehicle walking; and a cover portion covering the opening of the wall portion of the liquid storage tube; and The diaphragm divides the storage chamber into a liquid chamber and an air chamber, and is characterized in that an air passage is provided in the cover portion or the wall portion of the liquid storage cylinder, and the air passage has an opening opening to the outside on the side of the vehicle in the forward direction. And communicates with the air chamber at a position shifted from the opening through the periphery of the storage chamber. The master cylinder according to item 1 of the scope of patent application, wherein the atmospheric passage is formed by bending between the cover portion and the wall portion of the reservoir tube. The master cylinder according to item 1 of the patent application range, wherein the atmospheric passage communicates with the air chamber at a rear direction side of the vehicle. The master cylinder according to item 1 of the patent application range, wherein the atmospheric passage communicates with the air chamber in a lateral direction of the vehicle. The master cylinder according to item 2 of the scope of patent application, wherein the atmospheric passage communicates with the air chamber on the side in the forward direction of the vehicle. A liquid reservoir is connected to a master cylinder that supplies brake fluid to a brake sub-pump, and is capable of storing the brake fluid, and is characterized in that: the liquid reservoir has a wall portion surrounding the reservoir for the brake The liquid storage storage chamber is formed, and the upper part is formed with an opening, and the outer side bears the flow of the atmosphere during vehicle walking; and a cover part covering the opening of the wall part of the liquid storage tank; The air chamber is provided with an air passage in the cover portion or the wall portion of the reservoir tube, and the air passage has an opening opening to the outside in the direction of the vehicle's forward direction, and passes through the periphery of the storage chamber and deviates from the opening. The shifted position communicates with the aforementioned air chamber. The liquid storage cartridge according to item 6 of the scope of patent application, wherein the atmospheric passage is formed by bending between the cover portion and the wall portion of the liquid storage tube. The liquid storage cartridge according to item 6 of the scope of patent application, wherein the atmospheric passage communicates with the air chamber on a rear side of the vehicle. The liquid storage cartridge according to item 6 of the scope of patent application, wherein the atmospheric passage communicates with the air chamber in a side direction of the vehicle. The liquid storage cartridge according to item 7 in the scope of the patent application, wherein the atmospheric passage communicates with the air chamber on the vehicle's forward direction side.