CN102897160A - Master cylinder - Google Patents

Abstract

The invention provides a master oil cylinder capable of improving manufacturing efficiency. A flange portion (114) extending radially outward is provided on the front end side of the insertion portion (34), and the connecting portion (28) has a flange portion (114) arranged on the front end side of its inner peripheral surface and having a diameter larger than the outer diameter of the flange portion. The ring-shaped fitting convex part (38), the middle diameter part (39) which is arranged on the proximal end side of the fitting convex part and has a larger diameter than the fitting convex part, is located on the proximal side of the middle diameter part and has a diameter larger than the middle diameter The large-diameter part (40) with a larger part, the small-diameter part (41) which is located on the base end side of the large-diameter part and is arranged at a position that can face the flange part and has a diameter smaller than the fitting convex part, and the sealing member (13) has The base end portion (68) with a large diameter that abuts against the front end surface (35) of the connection portion (28), the ring-shaped fitting recess (69) that fits with the fitting convex portion of the connection portion, is arranged on the fitting A sealing cylinder part (70) on the side opposite to the base end part of the concave part and in contact with the middle diameter part of the insertion part and the connection part.

Description

master cylinder

technical field

The present invention relates to a master cylinder for supplying hydraulic pressure to a wheel brake cylinder of a vehicle.

Background technique

In a master cylinder that supplies hydraulic pressure to a wheel cylinder of a vehicle, there is a technique for preventing a tank that supplies hydraulic oil to the cylinder from falling out of the cylinder (for example, refer to Patent Document 1).

Patent Document 1: (Japanese) Unexamined Patent Publication No. 2001-158337

When the above-mentioned structure that prevents the oil tank from falling out of the cylinder is adopted, it is difficult to assemble the oil tank to the cylinder, and the manufacturing efficiency of the master cylinder may be lowered.

Contents of the invention

Therefore, an object of the present invention is to improve the manufacturing efficiency of the master cylinder.

In order to achieve the above object, the master cylinder described in the first aspect of the invention has: an oil cylinder for generating pressure by sliding a piston; an oil tank for supplying working fluid to the oil cylinder; a connection part; a cylindrical insertion part provided on the oil tank and inserted into the connection part; a cylinder provided between the connection part and the insertion part and having elasticity to seal between the connection part and the insertion part The shape of the sealing member is characterized in that the insertion part has a flange part expanding radially outward on the front end side, and the connecting part has a flange part provided on the front end side of its inner peripheral surface and having a diameter larger than that of the flange part. a ring-shaped first inner diameter part with a large outer diameter; a second inner diameter part provided on the base end side of the first inner diameter part and having a diameter larger than the diameter of the first inner diameter part; located at the base end of the second inner diameter part A third inner diameter portion on the side and having a diameter larger than that of the second inner diameter portion. The sealing member has: a base end portion with a large diameter that abuts against the front end surface of the connection portion; A ring-shaped fitting part in which the inner diameter part fits; it is provided on the opposite side of the fitting part in the axial direction from the base end part and is connected to the second inner diameter part of the insertion part and the connecting part abutting seal cylinder.

In the master cylinder according to the second aspect of the invention, the sealing member is provided with a protruding portion having a diameter larger than that of the sealing cylindrical portion at the front end portion of the sealing cylindrical portion on its outer peripheral surface.

According to the third aspect of the invention, the master cylinder is characterized in that the third inner diameter portion of the connecting portion has a diameter-reducing portion whose diameter gradually decreases toward the second inner diameter portion.

The master cylinder according to the fourth aspect of the invention is characterized in that at least a part of the protruding portion is configured to be in contact with the second inner diameter portion in a state of use.

According to the fifth aspect of the invention, the master cylinder is characterized in that the connecting portion has a fourth inner diameter portion smaller in diameter than the first inner diameter portion, and the fourth inner diameter portion is located at the base of the third inner diameter portion. The end side is provided at a position capable of facing the flange portion.

According to the present invention, the manufacturing efficiency of the master cylinder can be improved.

Description of drawings

Fig. 1 is a side view showing a main part of a master cylinder according to a first embodiment in section.

Fig. 2 is a partially enlarged cross-sectional view showing a connection portion of the master cylinder according to the first embodiment.

Fig. 3 is a view showing a seal member of the master cylinder according to the first embodiment, Fig. 3(a) is a sectional view, and Fig. 3(b) is a front view.

4 is a partially enlarged cross-sectional view showing an insertion portion of the master cylinder according to the first embodiment.

5( a ) to ( c ) are partially enlarged cross-sectional views showing the steps of assembling the master cylinder of the first embodiment in the order of ( a ) to ( c ).

Fig. 6 is a diagram showing a seal member of a master cylinder according to a second embodiment, Fig. 6(a) is a cross-sectional view, and Fig. 6(b) is a front view.

7( a ) to ( d ) are partially enlarged cross-sectional views showing the steps of assembling the master cylinder of the second embodiment in the order of ( a ) to ( d ).

8 is a partially enlarged cross-sectional view showing a connection portion of a master cylinder according to a third embodiment.

9( a ) to ( b ) are partially enlarged cross-sectional views showing the steps of assembling the master cylinder of the third embodiment in the order of ( a ) to ( b ).

Explanation of reference signs

12 fuel tanks

13, 13A Sealing parts

17 oil cylinder

21, 22 Piston

28, 28B connection part

34 Insertion part

35 front face

38 Fitting convex part

39 middle diameter part

40, 40B large diameter part

41, 41B Small diameter department

53 Conical part (reducing diameter part)

68 Base end

69 Fitting recess

70, 70A sealed barrel

114 Flange

131 protrusion

Detailed ways

Hereinafter, master cylinders according to each embodiment of the present invention will be described.

"First Embodiment"

A master cylinder according to a first embodiment will be described with reference to FIGS. 1 to 5 . As shown in FIG. 1 , the master cylinder has a master cylinder body 11, a synthetic resin oil tank 12 integrally mounted on the upper side of the master cylinder body 11 in the vertical direction, and a part for sealing the gap between the master cylinder body 11 and the oil tank 12. For the seal members 13, 13 made of rubber. The master cylinder main body 11 generates hydraulic oil pressure corresponding to an operation amount of a brake pedal (not shown), and supplies it to a wheel cylinder such as a disc brake or a drum brake provided on a wheel. The oil tank 12 stores hydraulic oil (working fluid) and supplies it to the main cylinder main body 11 as needed.

The master cylinder body 11 has a bottomed cylindrical cylinder 17 having a bottom 15 and a cylindrical portion 16 extending from the peripheral portion of the bottom 15 in the axial direction thereof. The oil cylinder 17 is made of metal such as aluminum alloy, and is mounted on the vehicle with its longitudinal direction aligned with, for example, the front-rear direction of the vehicle.

The main cylinder main body 11 has: a main piston (piston) 21 slidably inserted into the side opposite to the bottom 15 in the cylinder 17; In the cylinder 17 , a sub-pressure chamber 23 is defined by the sub-piston 22 , the bottom 15 of the cylinder 17 , and the cylindrical portion 16 . In addition, in the cylinder 17 , a primary pressure chamber 24 is defined by the sub piston 22 , the primary piston 21 , and the cylindrical portion 16 of the cylinder 17 . Moreover, although not shown, a gap forming part including a spring is provided between the sub piston 22 and the bottom 15 of the oil cylinder 17, and the gap forming part determines the above-mentioned sub piston in the non-braking state without input from the brake pedal. The distance between the piston 22 and the bottom 15 of the cylinder 17. In addition, a space forming part including a spring is provided between the sub piston 22 and the main piston 21, and the space forming part determines the space between the sub piston 22 and the main piston 21 in the non-braking state.

Further, in the master cylinder main body 11 , when the master piston 21 slides toward the sub piston 22 side by the operation of a brake pedal (not shown), the pressure of the master pressure chamber 24 in the cylinder 17 rises. This increased pressure is transmitted to the wheel cylinders connected to the brake piping of one system. In addition, by the sliding of the main piston 21 , the sub-piston 22 slides toward the bottom 15 of the cylinder 17 through a not-shown space forming portion. As a result, the pressure in the sub pressure chamber 23 in the cylinder 17 rises, and the pressure is transmitted to the wheel cylinder connected to the brake pipe of another system. That is, by sliding the main piston 21 and the sub piston 22 , the cylinder 17 generates pressure to be transmitted to the wheel cylinder.

A pair of connecting parts 28 and 28 for connecting the oil tank 12 and the oil cylinder 17 are provided side by side on the oil cylinder 17 . The connecting portions 28 , 28 are integrally formed at an axially intermediate position of the cylindrical portion 16 so as to protrude radially outward of the cylindrical portion 16 . The above-mentioned connecting parts 28, 28 are matched with each other in the circumferential direction of the cylindrical part 16 and are separated from each other along the axial direction of the cylindrical part 16. Connecting holes 29 along the radial direction of the cylindrical part 16 of the oil cylinder 17 are respectively formed inside, Thus, a cylindrical shape along the radial direction of the cylindrical portion 16 of the cylinder 17 is formed.

The fuel tank 12 includes a tank main body 31 having a liquid supply port 30 , and a detachable cover 32 for opening and closing the liquid supply port 30 . The oil tank main body 31 has: the above-mentioned liquid supply port 30 for supplying working oil from the outside; a container part 33 located on the lower side of the liquid supply port 30 and storing the working oil; A pair of insertion parts 34, 34 for supplying hydraulic oil to the oil cylinder 17 are provided in a pair of connecting parts 28, 28. The insertion portions 34 , 34 have a cylindrical shape parallel to each other and are integrally formed with the tank main body 31 . Specifically, it is formed to protrude from the container portion 33 toward an example opposite to the liquid supply port 30 , that is, vertically downward.

An insertion portion 34 of the oil tank 12 is connected to a connection portion 28 of the oil cylinder 17 via a sealing member 13 . In addition, the other insertion portion 34 of the oil tank 12 is connected to the other connecting portion 28 of the oil cylinder 17 via the other sealing member 13 . Therefore, the master cylinder main body 11 receives hydraulic oil supplied from the oil tank 12 through the pair of connecting portions 28 , 28 of the oil cylinder 17 . A pair of sealing members 13 , 13 are formed in a substantially cylindrical shape, and are each provided between the corresponding connection portion 28 and the insertion portion 34 inserted thereinto. The pair of sealing members 13 and 13 have elasticity, and seal the gap between the respective connecting portion 28 and the insertion portion 34 .

A structure in which one insertion portion 34 is attached to one connection portion 28 of the above-mentioned oil cylinder 17 via one seal member 13 is the same as a structure in which another insertion portion 34 is attached to the other connection portion 28 via another seal member 13 . Therefore, below, referring to FIGS. 2 to 5 , one connecting portion 28 , one sealing member 13 , one insertion portion 34 , and their joining structures will be described in detail.

First, the connecting portion 28 of the cylinder 17 will be described. As shown in FIG. 2 , the opening end of the connection portion 28 , that is, the front end surface 35 at the end opposite to the cylindrical portion 16 is formed in a flat circular ring shape perpendicular to the connection hole 29 . In addition, the bottom surface 36 of the proximal end of the connecting portion 28 on the cylindrical portion 16 side is formed in a flat circular shape perpendicular to the connecting hole 29 .

Furthermore, the inner peripheral surface of the connecting portion 28 has a fitting convex portion 38 , a middle diameter portion 39 , a large diameter portion 40 , and a small diameter portion 41 . The fitting convex portion 38 (first inner diameter portion) is formed in an annular shape protruding inward on the front end surface 35 side which is the opening side of the connection portion 28 . The middle diameter portion 39 (second inner diameter portion) is provided adjacent to the fitting convex portion 38 on the cylindrical portion 16 side in the axial direction of the fitting convex portion 38 , that is, on the base end side, and has a diameter larger than the inner diameter of the fitting convex portion 38 . Inner diameter size. The large-diameter portion 40 (third inner-diameter portion) is provided adjacent to the middle-diameter portion 39 on the cylindrical portion 16 side in the axial direction of the middle-diameter portion 39 , and has an inner diameter larger than the inner diameter of the middle-diameter portion 39 . The small-diameter portion 41 (fourth inner-diameter portion) is provided adjacent to the large-diameter portion 40 on the cylindrical portion 16 side in the axial direction of the large-diameter portion 40 , and is formed so that the inner diameter is larger than the fitting convex portion 38 , the middle-diameter portion 39 , and the large-diameter portion. The inner diameter of any of the portions 40 is small.

The fitting convex portion 38 has a tapered front surface 44 , a cylindrical front surface 45 , a small tapered surface 46 , and a stepped surface 47 .

The tapered front end portion 44 is formed in a tapered shape with a diameter that becomes smaller as it goes from the inner peripheral portion of the front end face 35 toward the cylindrical portion 16 , and extends toward the cylindrical portion 16 . The front end side cylindrical surface portion 45 extends from the end edge portion of the front end tapered portion 44 on the side of the barrel portion 16 with a constant diameter toward the side of the barrel portion 16 . The small tapered portion 46 is formed in a tapered shape whose diameter increases toward the cylindrical portion 16 from the edge portion of the cylindrical portion 16 of the front end side cylindrical portion 45 and extends toward the cylindrical portion 16 . The stepped surface portion 47 is formed in an annular shape extending radially outward with a constant width from the end edge portion of the small tapered portion 46 on the cylindrical portion 16 side.

The middle diameter portion 39 has an intermediate cylindrical surface portion 50 extending from the large-diameter end edge portion of the stepped surface portion 47 toward the cylindrical portion 16 with a constant diameter. The diameter of the intermediate cylindrical surface 50 is larger than the diameter of the front cylindrical surface 45 .

The large-diameter portion 40 has a tapered portion 53 (reduced diameter portion), a curved portion 54 , and a tapered portion 55 .

The tapered portion 53 is formed in a tapered shape whose diameter increases toward the cylindrical portion 16 from the end edge portion of the intermediate cylindrical portion 50 on the cylindrical portion 16 side, and extends toward the cylindrical portion 16 . That is, the tapered surface portion 53 of the large-diameter portion 40 gradually decreases in diameter toward the middle-diameter portion 39 . The curved surface portion 54 extends toward the cylindrical portion 16 from the end edge portion of the tapered portion 53 on the cylindrical portion 16 side in such a manner that the diameter increases toward the cylindrical portion 16 side and becomes smaller toward the cylindrical portion 16 side, and includes a connecting hole. The cross-sectional shape of the central axis of 29 is arc-shaped.

The tapered portion 55 is formed in a tapered shape whose diameter decreases toward the cylindrical portion 16 from the edge portion of the curved portion 54 on the cylindrical portion 16 side, and extends toward the cylindrical portion 16 . The smallest diameter of the tapered portion 55 is smaller than the diameters of the front cylindrical portion 45 and the intermediate cylindrical portion 50 , and the large diameter portion of the tapered portion 55 equal to or greater than the diameter of the intermediate cylindrical portion 50 constitutes the large diameter portion 40 . That is, the tapered portion 55 is bounded by the position of the intersection line with the extended surface of the intermediate cylindrical portion 50 , the side of the curved surface 54 constitutes the large diameter portion 40 , and the side opposite to the curved portion 54 constitutes the small diameter portion 41 .

The small-diameter portion 41 has a portion having a diameter smaller than that of the intermediate cylindrical surface portion 50 of the above-mentioned tapered portion 55 , a proximal-side cylindrical surface portion 58 , and a proximal-side tapered portion 59 .

The proximal cylindrical surface portion 58 extends from the end edge portion of the tapered portion 55 on the cylindrical portion 16 side with a constant diameter toward the cylindrical portion 16 side. Therefore, the diameter of the proximal cylindrical surface 58 is smaller than that of the intermediate cylindrical surface 50 and smaller than that of the distal cylindrical surface 45 , and the diameter of the small diameter portion 41 is smaller than that of the fitting convex portion 38 . The proximal tapered portion 59 is formed in a tapered shape with a diameter that becomes smaller as it goes toward the cylindrical portion 16 from the end edge portion of the proximal cylindrical portion 58 on the cylindrical portion 16 side, and extends toward the cylindrical portion 16 . connected.

A chamfered surface 60 is formed on the outer peripheral side of the opening end of the connection portion 28 , and the chamfered surface 60 increases in diameter from the outer peripheral end edge portion of the front end surface 35 toward the cylindrical portion 16 in the axial direction.

In addition, the above-mentioned front end face 35, chamfered face 60, front tapered face 44, front cylindrical face 45, small tapered face 46, stepped face 47, middle cylindrical face 50, tapered face 53, curved face 54, tapered face 55 The center axes of the base end side cylindrical surface portion 58 and the base end side tapered portion portion 59 are all coincident with each other. Therefore, the central axes of the fitting convex portion 38 , the intermediate portion 39 , the large diameter portion 40 , and the small diameter portion 41 are all coincident with each other, and the central axis is the central axis of the connection hole 29 .

Next, the rubber seal member 13 in a natural state before being fitted with the connecting portion 28 of the oil cylinder 17 , that is, before being inserted into the insertion portion 34 of the oil tank 12 will be described. As shown in FIG. 3 , the seal member 13 has a cylindrical shape, and a large-diameter end surface 63 at one axial end and a smaller-diameter small-diameter end surface 64 at the other axial end are formed in a flat shape extending in a direction perpendicular to the axis.

On the outer peripheral surface of the sealing member 13, there are: an annular base end portion 68 with a large diameter; and an annular fitting recess 69 (fitting portion) provided adjacent to the base end portion 68 in the axial direction, and It is recessed radially inward so that the smallest diameter is smaller than the diameter of the base end portion 68 . In addition, there is also a cylindrical sealing cylinder portion 70, which is provided adjacently in the axial direction on an example of the fitting recess 69 opposite to the base end portion 68, and has a diameter larger than the minimum diameter of the fitting recess 69 and larger than the base end portion. The diameter of 68 is small.

The base end portion 68 has an end-side cylindrical surface portion 73 , an end-side stepped surface portion 74 , an intermediate cylindrical surface portion 75 , and an intermediate stepped surface portion 76 .

The one-end cylindrical surface portion 73 extends from the outer peripheral portion of the large-diameter end surface 63 toward the small-diameter end surface 64 at a constant diameter. The one-end-side stepped surface portion 74 is formed in an annular shape extending from the end edge portion of the one-end-side cylindrical surface portion 73 on the small-diameter end surface 64 side toward the radially inner side with a constant width.

The intermediate cylindrical surface portion 75 extends from the small-diameter-side edge portion of the one-end-side stepped surface portion 74 toward the small-diameter end surface 64 side with a constant diameter. Therefore, the diameter of the intermediate cylindrical surface portion 75 is smaller than the diameter of the one end side cylindrical surface portion 73 . The intermediate stepped surface portion 76 is formed in an annular shape that spreads radially inward with a constant width from the edge portion of the intermediate cylindrical portion 75 on the small-diameter end surface 64 side.

Here, the minimum diameter of the base end portion 68 is larger than the outer diameter of the opening-side end portion of the connection portion 28 shown in FIG. 2 . That is, any one of the diameters of the one end side cylindrical surface 73, the one end side stepped surface 74, and the intermediate cylindrical surface 75 of the base end portion 68 is larger than the outer diameter of the front end surface 35 of the connection portion 28, and is larger than the diameter of the chamfered surface. The outer diameter of 60 is large.

The fitting concave portion 69 has: a part of the small-diameter side of the intermediate stepped surface 76 ; a curved surface 79 ; a smallest-diameter cylindrical surface 80 ; a curved surface 81 ;

The curved surface 79 extends from the small-diameter end edge of the intermediate step surface 76 toward the small-diameter end surface 64 so that the diameter becomes smaller toward the small-diameter end surface 64 , and the shape of the cross section including the central axis of the sealing member 13 is arc-shaped. .

The smallest-diameter cylindrical surface portion 80 extends from the small-diameter-side edge portion of the curved surface portion 79 toward the small-diameter end surface 64 at a constant diameter. Therefore, the diameter of the smallest-diameter cylindrical surface portion 80 is smaller than the diameters of the one-end cylindrical surface portion 73 and the intermediate cylindrical surface portion 75 .

The curved surface portion 81 extends from the edge portion of the smallest-diameter cylindrical portion 80 on the small-diameter end surface 64 side toward the small-diameter end surface 64 so that the diameter increases toward the small-diameter end surface 64 side, and has a cross-sectional shape including the central axis of the sealing member 13 It is arc-shaped. The other end-side stepped surface portion 82 is formed in an annular shape extending radially outward with a constant width from the end edge portion of the curved surface portion 81 on the small-diameter end surface 64 side.

Here, the minimum outer diameter of the fitting concave portion 69 is larger than the minimum inner diameter of the fitting convex portion 38 of the connection portion 28 shown in FIG. 2 . That is, the diameter of the smallest-diameter cylindrical surface portion 80 of the fitting concave portion 69 is larger than the diameter of the front end side cylindrical surface portion 45 of the fitting convex portion 38 . In addition, the axial width of the fitting concave portion 69 is wider than the axial length of the fitting convex portion 38 of the connection portion 28 . That is, the axial distance between the middle stepped surface 76 and the other end side stepped surface 82 of the fitting recess 69 is longer than the axial distance between the front end surface 35 of the connecting portion 28 and the stepped surface 47 .

Two ribs 85 , 86 having the same outer diameter and a rib 87 located between them and having a smaller outer diameter than them are formed on the seal cylinder portion 70 . The seal cylinder portion 70 has a convex portion 88 constituting the outer surface of the rib 85, a convex portion 89 constituting the outer surface of the rib 87, a convex portion 90 constituting the outer surface of the rib 86, a cylindrical portion 91 on the other end side, and a tapered portion on the other end side. Facial92.

The convex portion 88 expands in diameter from the outer-diameter side edge portion of the other end-side stepped portion 82 so that the diameter increases toward the small-diameter end surface 64 , and then decreases in diameter so that the diameter becomes smaller toward the small-diameter end surface 64 . Extends toward the small-diameter end surface 64 side. The shape of the cross section of the convex portion 88 including the central axis of the sealing member 13 is an arc shape.

The convex portion 89 expands in diameter from the end edge portion of the convex portion 88 on the small-diameter end surface 64 side so that the diameter increases toward the small-diameter end surface 64 side, and then shrinks in diameter so that the diameter becomes smaller toward the small-diameter end surface 64 side, and then moves toward the small-diameter end surface 64. The end surface 64 extends sideways. The cross-sectional shape of the convex portion 89 including the central axis of the sealing member 13 is also arc-shaped.

The convex portion 90 expands in diameter from the end edge portion of the convex portion 88 on the small-diameter end surface 64 side so that the diameter increases toward the small-diameter end surface 64 side, and then shrinks in diameter so that the diameter becomes smaller toward the small-diameter end surface 64 side, and then moves toward the small-diameter end surface 64. The end surface 64 extends sideways. The shape of the cross section of the convex portion 90 including the central axis of the sealing member 13 is also arc-shaped.

The other end-side cylindrical surface portion 91 extends from the end edge portion of the convex portion 90 on the small-diameter end surface 64 side with a constant diameter toward the small-diameter end surface 64 side. The other-end tapered portion 92 extends from the end of the other-end cylindrical portion 91 on the small-diameter end surface 64 side to the small-diameter end surface 64 in such a manner that the diameter becomes smaller toward the small-diameter end surface 64 , and is continuous with the small-diameter end surface 64 .

The maximum outer diameter of the seal cylinder portion 70 is larger than the diameter of the middle diameter portion 39 of the connection portion 28 . That is, the outer diameters of the convex portions 88 and 90 of the seal cylinder portion 70 are larger than the diameter of the intermediate cylindrical portion 50 of the connection portion 28 .

The axial length of the seal cylinder portion 70 is longer than the axial length of the middle diameter portion 39 of the connecting portion 28 and is substantially equal to the axial length of the middle diameter portion 39 and the large diameter portion 40 combined. In other words, the axial length of the seal cylinder portion 70 is shorter than the combined axial length of the middle diameter portion 39 , the large diameter portion 40 , and the small diameter portion 41 of the connecting portion 28 . The axial length between the other end side stepped surface 82 of the seal cylinder 70 and the small-diameter end surface 64 is equal to the axis between the intersecting position of the stepped surface 47 of the connecting portion 28 and the extension surface of the intermediate cylindrical surface 50 of the tapered surface 55 . The longitudinal length is shorter than the axial length between the stepped surface portion 47 of the connecting portion 28 and the end portion of the tapered portion 55 on the proximal side cylindrical surface portion 58 side.

A plurality of, specifically, two ribs 95 and 96 are formed on the inner peripheral portion of the sealing member 13 . The inner peripheral surface of the sealing member 13 has a one-end tapered surface 99, a one-end stepped surface 100, a one-end curved surface 101, a one-end cylindrical surface 102, a convex surface 103 constituting the outer surface of the rib 95, and a middle cylindrical surface 104. , the convex surface 105 constituting the outer surface of the rib 96 , and the other end side cylindrical surface 106 .

The one-end tapered portion 99 is formed in a tapered shape with a diameter that decreases from the inner peripheral portion of the large-diameter end surface 63 toward the small-diameter end surface 64 , and extends toward the small-diameter end surface 64 . The one-end-side stepped surface portion 100 is formed in an annular shape extending from the end edge portion of the one-end-side tapered portion 99 on the small-diameter end surface 64 side toward the radially inner side with a constant width. The one-end curved surface 101 extends from the inner peripheral portion of the one-end stepped surface 100 toward the small-diameter end surface 64 so that the diameter becomes smaller toward the small-diameter end surface 64 , and the shape of the cross-section including the central axis of the sealing member 13 is an arc. shape. The one-end cylindrical surface portion 102 extends from the end edge portion of the one-end tapered portion 99 on the small-diameter end surface 64 side to the small-diameter end surface 64 side with a constant diameter.

The convex portion 103 expands in diameter from the end edge portion of the small-diameter end surface 64 side of the one-end side cylindrical portion 102 so that the diameter increases toward the small-diameter end surface 64 side, and then shrinks in diameter so that the diameter becomes smaller toward the small-diameter end surface 64 side. And it extends toward the small-diameter end surface 64 side. The shape of the cross section of the convex portion 103 including the central axis of the sealing member 13 is an arc shape. The intermediate cylindrical surface portion 104 extends from the end edge portion of the convex portion 103 on the small-diameter end surface 64 side to the small-diameter end surface 64 side with the same constant diameter as the one-end cylindrical surface portion 102 . The convex portion 105 expands in diameter from the end edge portion of the intermediate cylindrical portion 104 on the small-diameter end surface 64 side so that the diameter increases toward the small-diameter end surface 64 side, and then decreases in diameter so that the diameter becomes smaller toward the small-diameter end surface 64 side, and Extends toward the small-diameter end surface 64 side. The shape of the cross-section of the convex portion 105 including the central axis of the sealing member 13 is an arc shape.

The other end side cylindrical surface 106 extends from the end edge of the convex portion 105 on the small diameter end surface 64 side to the small diameter end surface 64 at the same constant diameter as the one end side cylindrical surface 102 and the middle cylindrical surface 104, and is connected to the small diameter end surface. 64 connected.

The large-diameter end surface 63, the small-diameter end surface 64, the one-end cylindrical surface 73, the one-end stepped surface 74, the middle cylindrical surface 75, the middle stepped surface 76, the curved surface 79, the smallest-diameter cylindrical surface 80, and the curved surface of the sealing member 13 81. The other end side stepped surface 82, convex surface 88, convex surface 89, convex surface 90, the other end side cylindrical surface 91, the other end side cone surface 92, one end side cone surface 99, one end side stepped surface 100, one end side The central axes of the curved surface 101 , the one end cylindrical surface 102 , the convex surface 103 , the middle cylindrical surface 104 , the convex surface 105 , and the other end cylindrical surface 106 are all identical, and all are the central axis of the sealing member 13 . The middle cylindrical surface portion 104 , the convex portion 105 , and the other end side cylindrical surface portion 106 constitute the inner peripheral surface of the seal cylinder portion 70 .

Next, the insertion portion 34 made of a synthetic resin having a higher rigidity than the sealing member 13 will be described. As shown in FIG. 4 , an upwardly recessed storage recess 110 is formed on the lower surface of the container portion 33 of the tank main body 31 , and the insertion portion 34 protrudes vertically downward from the center of the storage recess 110 . In addition, the housing recess 110 has an annular bottom surface 111 perpendicular to the central axis of the insertion portion 34 , and a fixed portion extending downward from the large-diameter side end edge of the bottom surface 111 to be perpendicular to the bottom surface 111 . The cylindrical surface 112 of the diameter.

The insertion portion 34 is formed in a shape having a cylindrical cylindrical portion 113 and a flange portion 114 . The cylindrical portion 113 extends with a substantially constant diameter from the bottom surface 111 of the storage recess 110 to the vicinity of the front end, and the flange portion 114 extends radially outward from the front end side of the cylindrical portion 113 opposite to the storage recess 110 .

The inner peripheral surface 116 of the cylindrical part 113 communicating with the inside of the container part 33 has a constant diameter, and the outer peripheral surface has a bottom curved surface 117 and a main cylindrical surface 118 . The bottom curved surface 117 is located at the boundary with the bottom surface 111 of the housing recess 110, extends toward the flange 114 in such a manner that the diameter becomes smaller toward the flange 114, and includes the central axis of the insertion portion 34. The shape is arc-shaped. The main cylindrical surface portion 118 extends perpendicularly to the bottom surface portion 111 at a constant diameter from the end edge portion on the small diameter side of the bottom curved surface portion 117 . A front end surface 119 of the cylindrical portion 113 opposite to the bottom surface 111 is parallel to the bottom surface 111 .

The flange portion 114 has a locking stepped surface 120 , a locking cylindrical surface 121 , and a front tapered surface 122 . The locking stepped surface portion 120 is formed in an annular shape extending radially outward from the end edge portion of the main cylindrical surface portion 118 on the front end surface 119 side with a constant width. The locking cylindrical surface portion 121 extends toward the front end surface 119 side with a constant diameter from the end edge portion on the outer diameter side of the locking stepped surface portion 120 . The tapered front end portion 112 extends from the end edge of the locking cylindrical portion 121 on the front end face 119 side toward the front end face 119 such that the diameter becomes smaller toward the front end face 119 , and is continuous with the front end face 119 .

The central axes of the inner peripheral surface 116, the bottom curved surface 117, the main cylindrical surface 118, the locking step surface 120, the locking cylindrical surface 121, the front tapered surface 122 and the front end surface 119 are all consistent, and all of them are part of the insertion part 34. central axis. The central axis of the insertion portion 34 also coincides with the central axes of the bottom surface 111 and the cylindrical surface 112 of the storage recess 110 , and is perpendicular to the bottom surface 111 of the storage recess 110 .

Here, the axial length of the insertion portion 34 excluding the range of the flange portion 114, that is, the axial length of the bottom curved surface 117 and the main cylindrical surface 118, in other words, the distance between the bottom surface 111 and the locking step surface 120 The axial length is longer than the entire axial length of the seal member 13 . In addition, the diameter of the main cylindrical surface 118 of the insertion portion 34 is equal to the diameter of the one end cylindrical surface 102, the middle cylindrical surface 104, and the other end side cylindrical surface 106 of the sealing member 13, and is smaller than the diameters of the convex portions 103, 105. The minimum diameter is large. In addition, the outer diameter of the flange portion 114 , that is, the diameter of the locking cylindrical surface 121 is larger than the diameters of the one end cylindrical surface 102 , the middle cylindrical surface 104 , and the other end cylindrical surface 106 of the sealing member 13 . In addition, the minimum diameter of the tip tapered surface portion 122 of the flange portion 114 is smaller than the maximum diameter of the one end side curved surface portion 101 of the sealing member 13 . In addition, the maximum diameter of the housing recess 110 , that is, the diameter of the cylindrical surface portion 112 is equal to the diameter of the maximum outer diameter of the base end portion 68 of the sealing member 13 , that is, the diameter of the one-end side cylindrical surface portion 73 .

The outer diameter of the flange portion 114 of the insertion portion 34 , that is, the diameter of the locking cylindrical surface 121 is smaller than the inner diameter of the ring-shaped fitting protrusion 38 of the connection portion 28 , that is, the diameter of the front cylindrical surface 45 . In other words, the fitting protrusion 38 provided on the front end side of the inner peripheral surface of the connecting portion 28 is formed in an annular shape having a diameter larger than the outer diameter of the flange portion 114 .

Next, the joining structure of the connection part 28, the sealing member 13, and the insertion part 34 is demonstrated according to the joining procedure.

First, as shown in FIG. 5( a ), the sealing member 13 is fitted to the connecting portion 28 . At this time, the sealing cylinder portion 70 of the sealing member 13 is fitted with the middle diameter portion 39 and the large diameter portion 40 of the connection portion 28 in an interference fit manner (るめめ代をもつ), and the fitting of the connection portion 28 is convex. The portion 38 fits into the fitting recessed portion 69 of the sealing member 13 in an interference fit manner. In addition, the base end portion 68 is brought into contact with the front end surface 35 of the connection portion 28 . Specifically, the intermediate step surface portion 76 of the sealing member 13 shown in FIG. 3 abuts against the front end surface 35 of the connection portion 28 shown in FIG. 2 abuts against the front cylindrical surface 45 of the connection portion 28 shown in FIG. In addition, the convex portion 88 and the convex portion 89 of the sealing member 13 shown in FIG. 90 and the other end side cylindrical surface 91 are deformed, abutting against the tapered surface 53, the curved surface 54 and the tapered surface 55 of the connecting portion 28 shown in FIG. It abuts against the tapered surface portion 55 of the connecting portion 28 shown in FIG. 2 .

Next, as shown in FIGS. 5( a ) to 5 ( b ) and further to FIG. 5 ( c ), the insertion portion 34 of the tank main body 31 is inserted into the seal member 13 held by the connection portion 28 . At this time, first, the insertion portion 34 abuts against the one end side curved surface portion 101 of the sealing member 13 on the front end tapered surface portion 122 of the front end side flange portion 114 as shown in FIG. 5( a ), and then the flange portion The locking cylindrical surface 121 of 114 is sequentially connected with the one end curved surface 101, the one end cylindrical surface 102, the convex surface 103, the middle cylindrical surface 104, the convex surface 105, and the other end cylindrical surface 106 of the sealing member 13. In contact, fitting is carried out while compressing and deforming these contacting parts and their adjacent parts radially outward and stretching in the axial direction. At this time, as shown in FIG. 5( b ), the large diameter portion 40 (third inner diameter portion) in front of the middle diameter portion 39 (second inner diameter portion) of the sealing member 13 is allowed to further deform radially outward, and the flange The sliding resistance exerted by the portion 114 is weakened. In addition, since the part of the seal member 13 that is pressed and deformed outward by the flange portion 114 is housed in the large diameter portion 40 (third inner diameter portion), it is possible to suppress the forward movement of the flange portion 114 in the insertion direction. According to the amount of protrusion, the sliding resistance applied to the flange portion 114 can also be weakened. In this way, in this embodiment, since the large diameter portion 40 (third inner diameter portion) is provided, even if the flange portion 114 is provided on the insertion portion 34, it is not difficult to assemble the oil tank 12 to the main cylinder body 11. Condition.

Next, when the flange portion 114 is pushed over the sealing member 113 as shown in FIG. 5( c ), the sealing member 13 and the insertion portion 34 come into close contact with each other with an interference fit. That is, when the insertion portion 34 is accurately inserted and held in the sealing member 13 of the connection portion 28, the one-end cylindrical surface portion 102, the convex portion 103, and the intermediate cylindrical surface portion on the inner peripheral side of the sealing member 13 shown in FIG. 104 , the convex portion 105 and the other end side cylindrical portion 106 are in contact with the main cylindrical portion 118 of the insertion portion 34 shown in FIG. 4 in an interference fit manner. At this time, the seal cylinder portion 70 on the outer peripheral side of the seal member 13 comes into contact with the middle diameter portion 39 and the large diameter portion 40 of the connection portion 28 in an interference fit manner.

In addition, at this time, as shown in FIG. 5( c ), the base end portion 68 of the seal member 13 is accommodated in the accommodation recessed portion 110 of the tank main body 31 . That is, the large-diameter end surface 63 of the sealing member 13 shown in FIG. 3 abuts against the bottom surface 111 of the housing recess 110 shown in FIG. The cylindrical surface portion 112 of the accommodation recessed portion 110 shown in FIG.

In addition, at this time, as shown in FIG. 5( c ), the flange portion 114 is away from the small-diameter end surface 54 of the sealing member 13 , and axially overlaps and radially opposes the small-diameter portion 41 of the connection portion 28 . In other words, the small-diameter portion 41 of the connection portion 28 is provided at a position capable of facing the flange portion 114 . In addition, the position of the flange 114 changes back and forth depending on the amount of deformation of the base end portion 68 and the position at which the insertion portion 34 is inserted into the sealing member 13 . However, if the insertion portion 34 is inserted until the base end portion 68 is compressed by at least the receiving recessed portion 110 and the connection portion 28, the flange portion 114 can be placed in the same position as the base end side cylindrical surface portion 58 of the small diameter portion 41. The base-end side cylindrical surface portion 58 of the connection portion 28 is in a state where the axial position overlaps and radially faces each other.

Here, in the technology described in the above-mentioned Patent Document 1, a claw portion protruding radially inward is provided at the front end of the connection portion (projection portion) of the master cylinder main body, and a claw protruding radially outwardly is provided on the seal member to be in contact with the radially outer side. A cylindrical part that locks the axially inner side of the claw part, and a flange part that expands radially outward is provided at the front end part of the insertion part (connecting leg part) of the oil tank, and the flange part is aligned with the shaft of the seal member. Lock inward. In the case of the above-mentioned structure, in order to restrict the detachment of the connecting leg from the boss, it is necessary to increase the amount of extension of the flange, but when increasing the amount of extension of the flange, it is necessary to align with the inner circumference of the boss. The seal member in surface contact is greatly deformed, which reduces the assemblability of the oil tank and the main cylinder body, and further reduces the manufacturing efficiency. Therefore, in the technique described in Patent Document 1, by making the flange portion eccentric, especially, the drop-off during vacuum filling of hydraulic oil is restricted, and assemblability is improved. However, in the technique described in Patent Document 1, it is difficult to say that it is possible to sufficiently restrain the connection leg from coming off the boss. On the other hand, in order to improve the assemblability and restrict the connecting leg from falling off the boss, the oil tank and the main cylinder main body can be held by pins to connect the oil tank to the main cylinder main body. However, if the pins are used, the number of parts increases, And the assembly steps increase.

On the other hand, in the master cylinder of the first embodiment, on the connecting portion 28 of the master cylinder main body 11, a middle diameter portion 39 having a diameter larger than the diameter is provided on the base end side of the fitting convex portion 38, and the middle diameter portion 39 A large-diameter portion 40 having a diameter larger than the diameter of the middle-diameter portion 39 is provided on the proximal end side thereof. Thus, when the flange portion 114 extending radially outward of the insertion portion 34 of the tank main body 31 is fitted to the seal member 13 locked by the middle diameter portion 39 of the connection portion 28 , if the seal member 13 is held by the flange The large-diameter portion 40 allows greater deformation of the sealing member 13 in the radial direction. Thereby, the sliding resistance of the sealing member 13 with respect to the insertion part 34 is weakened. In addition, since the portion of the sealing member 13 deformed outward by being pressed by the flange portion 114 is accommodated in the large-diameter portion 40, the amount of protrusion forward in the insertion direction as resistance of the flange portion 114 is suppressed. The sliding resistance applied to the flange portion 114 is also weakened. Therefore, even if the radial extension of the flange portion 114 is increased to restrict the insertion portion 34 from falling off the connecting portion 28 when the hydraulic oil is filled, etc., it is possible to achieve good assembly of the oil tank 12 and the oil cylinder 17, and to improve manufacturing efficiency. . Therefore, even if the oil tank 12 and the oil cylinder 17 are not connected by pins, but are connected only by inserting the insertion part 34 into the connection part 28 through the seal member 13, it is possible to restrict the insertion part 34 from falling off the connection part 28. .

In addition, since the connecting portion 28 has the small diameter portion 41 having a diameter smaller than that of the fitting convex portion 38 on the proximal side of the large diameter portion 40 so as to be able to face the flange portion 114, for example, even if the sealing The member 13 is stretched more than expected by the flange portion 114 , and the entry of the sealing member 13 between the flange portion 114 and the small-diameter portion 41 can be restricted, and damage to the sealing member 13 can be suppressed.

In addition, since the large-diameter portion 40 of the connecting portion 28 has the tapered portion 53 whose diameter gradually decreases toward the middle-diameter portion 39, the insertion portion 34 of the oil tank body 31 moves in the pulling-out direction due to the pressure of the hydraulic oil when filling the hydraulic oil. When the flange portion 114 comes into contact with the small-diameter end surface 64 of the sealing member 13 and presses the sealing member 13 in the pull-out direction, the sealing cylinder portion 70 is deformed to move radially inward by the guidance of the tapered surface portion 53 and closes it. The gap with the insertion portion 34 increases the contact pressure with the insertion portion 34 and increases the frictional force. Thereby, it is possible to further restrict the removal of the insertion portion 34 from the connection portion 28 .

"Second Embodiment"

Next, the master cylinder of the second embodiment will be described mainly based on FIG. 6 and FIG. 7 , focusing on portions different from the first embodiment. In addition, the same part as 1st Embodiment is represented with the same name and the same code|symbol.

In the second embodiment, a seal member 13A having a partially different seal cylinder portion 70A from the seal cylinder portion 70 of the seal member 13 of the first embodiment is used. The seal member 13A of the second embodiment is not provided with the rib 86 of the first embodiment, but is provided with a diameter larger than the diameter of the seal cylinder portion 70A, that is, a rib 85 at the front end portion of the seal cylinder portion 70A on its outer peripheral surface. An annular protrusion 131 with a large diameter. That is, the seal cylinder portion 70A has: the convex portion 88 constituting the outer surface of the rib 85 ; the convex portion 89 constituting the outer surface of the rib 87 ;

The stepped surface portion 132 expands radially outward in a direction perpendicular to the axis from an edge portion of the convex portion 88 on the small-diameter end surface 64 side. The curved surface 133 expands in diameter from the large-diameter end edge of the stepped surface 132 so that the diameter increases toward the small-diameter end surface 64 , and then decreases in diameter so that the diameter becomes smaller toward the small-diameter end surface 64 . The end surface 64 extends sideways. The cross section of the curved surface 133 including the central axis of the sealing member 13A has an arc shape. The tapered portion 134 extends toward the small-diameter end surface 64 , and is continuous with the small-diameter end surface 64 , and extends toward the small-diameter end surface 64 from the edge portion of the curved surface 133 on the small-diameter end surface 64 side so that the diameter becomes smaller toward the small-diameter end surface 64 .

The maximum outer diameter of the seal cylinder portion 70A, that is, the maximum outer diameter of the protruding portion 131 is larger than the outer diameter of the middle diameter portion 39 of the connection portion 28 . In addition, when the volume of the protruding portion 131 is V1 and the volume of the sealed retreat space inside the large diameter portion 40 is V2, V1<V2 is set. Furthermore, the axial length between the intermediate stepped surface portion 76 of the base end portion 68 and the position of the maximum outer diameter of the protruding portion 131 is shorter than the axial length between the front end surface 35 of the connection portion 28 and the position of the maximum inner diameter of the large-diameter portion 40 . , the axial length between the intermediate stepped surface 76 of the base end 68 and the stepped surface 132 of the protruding portion 131 is more Shorter in length. That is, the protruding portion 131 of the seal cylinder portion 70A and the intermediate diameter portion 39 of the connecting portion 28 are positioned to overlap in the axial direction.

Next, the joint structure among the connection part 28, the sealing member 13A, and the insertion part 34 is demonstrated according to the joining procedure.

First, as shown in FIG. 7( a ), the sealing member 13A is fitted to the connecting portion 28 . At this time, the sealing member 13A makes the protruding portion 131 of the sealing cylinder portion 70A contact the middle diameter portion 39 of the connecting portion 28, and the fitting convex portion 38 of the connecting portion 28 is fitted to the fitting concave portion 69, and the base end thereof 68 is in contact with the front end surface 35 of the connecting portion 28 . Specifically, the intermediate step surface 76 of the sealing member 13A shown in FIG. 6 abuts against the front end surface 35 of the connecting portion 28 shown in FIG. 2 abuts against the front cylindrical surface portion 45 of the connecting portion 28 shown in FIG. 6 , and the curved surface portion 133 of the sealing member 13 shown in FIG.

Next, as shown in FIGS. 7( a ) to 7 ( b ), and further to FIGS. 7 ( c ) and 7 ( d ), the insertion portion 34 of the tank main body 31 is inserted into the seal member 13A held by the connecting portion 28 . At this time, first, the insertion portion 34 comes into contact with the one end side curved surface portion 101 of the sealing member 13A on the front tapered surface portion 122 of the front end side flange portion 114 shown in FIG. The locking cylindrical surface 121 of the sealing member 13A sequentially contacts the one-end curved surface 101, the one-end cylindrical surface 102, the convex surface 103, the middle cylindrical surface 104, the convex surface 105, and the other-end cylindrical surface 106, Fitting is performed while compressing and deforming these contact portions and their adjacent portions radially outward and stretching in the axial direction. Then, the seal cylinder portion 70A is fitted into the middle diameter portion 39 and the large diameter portion 40 as shown in FIG. At this time, the seal cylinder portion 70A including the protruding portion 131 of the seal member 13A is allowed to further deform radially outward at the large-diameter portion 40 in front of the middle-diameter portion 39 , thereby weakening the sliding resistance applied to the flange portion 114 . In addition, since the seal cylinder portion 70A including the protruding portion 131 deformed outward due to the sealing member 13 being pressed by the flange portion 114 is accommodated in the large-diameter portion 40 , it is possible to suppress the resistance in the insertion direction of the flange portion 114 . The amount of protrusion in the front can also reduce the sliding resistance applied to the flange portion 114 from this point.

As shown in FIG. 7( c ), when the flange portion 114 exceeds the sealing member 13A, the sealing member 13A and the insertion portion 34 come into close contact with an interference fit. When the insertion portion 34 is properly inserted into the sealing member 13A held by the connection portion 28, the one-end side cylindrical surface 102, the convex surface 103, the middle cylindrical surface 104, the convex surface 105, and the other end of the sealing member 13A shown in FIG. The side cylindrical surface portion 106 is in contact with the main cylindrical surface portion 118 of the insertion portion 34 shown in FIG. 4 with an interference fit. At this time, as shown in FIG. 7( c ), the sealing cylinder portion 70A is in contact with the middle diameter portion 39 and the large diameter portion 40 of the connection portion 28 . Dimensional relationship, in the subsequent use state, at least a part of it is in contact with the middle diameter portion 39 , and the rest is in contact with the large diameter portion 40 . That is, at the time of assembly, the base end portion 68 is compressed by the receiving recessed portion 110 and the connection portion 28, even if there is a state where the entire protrusion portion 131 is in contact with the large-diameter portion 40 for a while, the base end portion 68 is restored by elastic force and the In the use state where the position of the tank main body 31 is stable, at least a part of the protruding portion 131 is in a state of being in contact with the middle diameter portion 39 .

According to the master cylinder of the second embodiment, since the protruding portion 131 having a diameter larger than the diameter of the seal cylinder portion 70A is provided at the front end portion of the seal cylinder portion 70A of the seal member 13A, the pressure of the hydraulic oil is utilized when filling the hydraulic oil. , the insertion portion 34 of the tank body 31 moves in the pulling direction, and when the flange portion 114 abuts against the small-diameter end surface 64 of the sealing member 13A and presses the sealing member 13 in the pulling direction, the sealing cylinder portion having the protruding portion 131 70A is deformed by moving radially inwardly according to the guidance of the tapered surface 53, and closes the gap between it and the insertion portion 34, thereby increasing the contact pressure applied to the insertion portion 34 and further increasing the frictional force. Thereby, it is possible to restrict the removal of the insertion portion 34 from the connection portion 28 .

In addition, since at least a part of the protruding portion 131 is provided so as to be in contact with the middle diameter portion 39 of the connection portion 28 in the use state, the sealing member 13A is always pushed radially inward from the middle diameter portion 39 , that is, toward the insertion portion 34 . pressure. Thus, the sealing member 13A can press the insertion portion 34 in the use state, and can restrict the insertion portion 34 from being pulled out from the connection portion 28 in the use state.

"Third Embodiment"

Next, a master cylinder according to a third embodiment will be described mainly based on FIG. 8 and FIG. 9 , focusing on portions different from those of the first embodiment. In addition, the same parts as those of the first embodiment are represented by the same names and the same symbols.

In the third embodiment, a connection portion 28B having a large-diameter portion 40B and a small-diameter portion 41B that is partially different from the connection portion 28 of the first embodiment is used. The large-diameter portion 40B and the small-diameter portion 41B of the connection portion 28B of the third embodiment have a curved surface portion 141 instead of the tapered portion 55 of the first embodiment.

The curved surface portion 141 is formed in a shape of a cross section including the central axis of the connecting hole 29 , extending toward the cylindrical portion 16 , and extending toward the cylindrical portion 16 side in an arc shape whose diameter becomes smaller from the end edge portion of the curved surface portion 54 on the cylindrical portion 16 side. It is arc-shaped. The radius of curvature of the curved surface 141 is larger than the radius of curvature of the curved surface 54 , and is formed in a shape that becomes larger as the distance from the curved surface 54 increases. A portion of the curved surface 141 connected to the base-end side cylindrical surface 58 is along a direction perpendicular to the axial direction of the connection hole 29 . In other words, the curved surface 141 is connected to the proximal cylindrical surface 58 orthogonally.

Next, the connection structure among the connection part 28B, the sealing member 13, and the insertion part 34 is demonstrated according to the joining procedure.

First, the sealing member 13 is fitted to the connecting portion 28B in the same manner as in the first embodiment. At this time, as shown in FIG. 9( a ), the sealing member 13 has its sealing cylinder portion 70 abutted against the middle diameter portion 39 and the large diameter portion 40B.

Next, as shown in FIGS. 9( a ) to 9 ( b ), the insertion portion 34 of the tank main body 31 is inserted into the seal member 13 held at the connection portion 28B in the same manner as in the first embodiment. At this time, even if the flange portion 114 of the insertion portion 34 stretches the seal member 13 more than expected, the seal member 13 can be restrained because the curved surface portion 141 curved perpendicularly to the proximal end side cylindrical surface portion 58 abuts on the seal member 13 . It enters between the flange portion 114 and the proximal-side cylindrical surface portion 58 of the small-diameter portion 41B.

According to the above-mentioned master cylinder of the third embodiment, since the curved surface portion 141 on the large-diameter portion 40B side of the small-diameter portion 41B is connected to the proximal-side cylindrical surface portion 58 so as to be perpendicular to the proximal-end-side cylindrical surface portion 58, the During assembly, for example, even if the seal member 13 is stretched more than expected by the flange portion 114 , entry of this portion between the flange portion 114 and the small-diameter portion 41B can be further restricted, and damage to the seal member 13 can be further suppressed.

According to the above-described embodiment, the oil cylinder that generates pressure by the sliding of the piston, the oil tank that supplies the working fluid to the oil cylinder, and the cylindrical connection portion that is provided on the oil cylinder and connects the oil tank is provided on the oil tank and inserted into the oil tank. In the master cylinder, a cylindrical insertion part in the connection part and a cylindrical sealing member provided between the connection part and the insertion part and having elasticity to seal between these connection parts and the insertion part have a The flange portion expanding radially outward on the front end side, the connecting portion has: an annular first inner diameter portion provided on the front end side of the inner peripheral surface and having a diameter larger than the outer diameter of the flange portion; A second inner diameter portion on the base end side of the first inner diameter portion and having a diameter larger than the first inner diameter portion, and a third inner diameter portion located on the base end side of the second inner diameter portion and having a diameter larger than the second inner diameter portion, The sealing member has: a base end portion with a large diameter that abuts on the front end surface of the connection portion, an annular fitting portion that fits into the first inner diameter portion of the connection portion, and a ring-shaped fitting portion provided on the fitting portion. A seal cylinder portion on the opposite side from the base end portion in the axial direction and abuts against the second inner diameter portion of the insertion portion and the connection portion. Thereby, it is possible to reduce the sliding resistance applied to the insertion portion by the sealing member. Therefore, good assemblability can be obtained even if the radial extension of the flange portion is increased to restrict the insertion portion from falling off the connection portion. In addition, since the connection portion has a small diameter portion with a diameter smaller than that of the fitting convex portion on the proximal side of the large diameter portion so as to be able to face the flange portion, even if the sealing member is stretched by the flange portion, for example, the As described above, entry of this portion between the flange portion and the small-diameter portion can also be restricted, and damage to the sealing member can be suppressed.

In addition, since the sealing member has a protruding portion having a diameter larger than that of the sealing cylindrical portion at the front end portion of the sealing cylindrical portion on the outer peripheral surface thereof, it is possible to restrict the insertion portion from coming off the connecting portion.

In addition, since the third inner diameter portion of the connection portion has a reduced diameter portion that gradually decreases in diameter toward the second inner diameter portion, when the insertion portion moves in the pulling direction relative to the connection portion, and the flange portion will seal When the component is pushed in the pulling-out direction, the sealing component moves radially inward according to the guidance of the reduced-diameter portion and deforms, thereby increasing the contact pressure applied to the insertion portion and increasing the frictional force. Thereby, it is possible to restrict the removal of the insertion portion from the connection portion.

In addition, since at least a part of the protruding portion is in contact with the second inner diameter portion in the use state, the sealing member can press the insertion portion in the use state, and can restrict the insertion portion from being pulled out from the connection portion in the use state. In addition, in each of the above-mentioned embodiments, an example was shown in which the seal member 13 and the insertion portion 34 of the oil tank were only connected to the connection portion 28 of the master cylinder to prevent falling off. The main cylinder that connects the main cylinder and the oil tank with pins, etc. Thereby, even if a pin etc. are forgotten to be inserted at the time of maintenance etc., it can prevent that a tank is pulled out from a master cylinder.

Claims (5)

1. master cylinder, it has:

Piston slides and the oil cylinder of generation pressure;

Supply with the fuel tank of working fluid to described oil cylinder;

Be arranged on the described oil cylinder and connect the tubular connecting portion of described fuel tank;

The tubular insertion section that is arranged on the described fuel tank and inserts described connecting portion;

Be arranged between described connecting portion and the described insertion section and have elasticity and seal the sealing element of the tubular between described connecting portion and the insertion section, this master cylinder is characterised in that,

Described insertion section has to the flange part of radial outside expansion in front,

Described connecting portion has: the first inside diameter of the ring-type that the front of the side face that sets within it and diameter are larger than the external diameter of described flange part; Be arranged on base end side and diameter second inside diameter larger than the diameter of this first inside diameter of this first inside diameter; Be positioned at base end side and diameter three inside diameter larger than the diameter of this second inside diameter of this second inside diameter,

Described sealing element has: the base end part large with the diameter of the front end face butt of described connecting portion; Fitting portion with the chimeric ring-type of the first inside diameter of described connecting portion; Be arranged on this fitting portion with described base end part vertically on the position of an opposite side and with the sealed chamber section of the second inside diameter butt of described insertion section and described connecting portion.

2. master cylinder according to claim 1 is characterized in that,

Described sealing element is at its outer peripheral face, is provided with diameter than the large protrusion of diameter of sealing cylinder section at the leading section of described sealed chamber section.

3. master cylinder according to claim 1 is characterized in that,

Described the 3rd inside diameter of described connecting portion has to described the second inside diameter reducing diameter part of diameter reduction gradually.

4. master cylinder according to claim 1 is characterized in that,

At least a portion of described protrusion is set to contact with described the second inside diameter under the use state.

5. each described master cylinder in 4 according to claim 1 is characterized in that,

Described connecting portion has diameter four inside diameter less than the diameter of described the first inside diameter, the 4th inside diameter be positioned at the base end side of described the 3rd inside diameter and be arranged on can be relative with described flange part the position on.

Images