CN102897160B - Master cylinder - Google Patents

Abstract

The invention provides a kind of master cylinder, it can improve manufacture efficiency.The flange part (114) extended to radial outside is provided with in the front of insertion section (34), connecting portion (28) has the front of the side face that sets within it and the fitting projection (38) of the diameter ring-type larger than the external diameter of flange part, be arranged on the base end side of fitting projection and the diameter central diameter portion (39) larger than fitting projection, be positioned at the base end side in central diameter portion and the diameter large-diameter portion (40) larger than central diameter portion, be positioned at large-diameter portion base end side and be arranged on can be relative with flange part position and the diameter minor diameter part (41) less than fitting projection, sealing element (13) has the large base end part (68) of the diameter that abuts with the front end face of connecting portion (28) (35), the chimeric recess (69) of the ring-type chimeric with the fitting projection of connecting portion, be arranged on the sealed chamber portion (70) abutted with base end part opposite side and with the central diameter portion of insertion section and connecting portion of chimeric recess.

Description

Master cylinder

Technical field

The present invention relates to the master cylinder of a kind of Of Wheel Brake Oil-Cylinders to vehicle supply hydraulic pressure.

Background technology

In the master cylinder of the Of Wheel Brake Oil-Cylinders supply hydraulic pressure to vehicle, there is the technology (such as with reference to patent documentation 1) suppressing the fuel tank to oil cylinder supply working oil to come off from oil cylinder.

Patent documentation 1:(Japan) JP 2001-158337 publication

When adopt above-mentioned such suppress fuel tank to come off from oil cylinder structure time, be difficult to fuel tank to be assembled on oil cylinder, and the manufacture efficiency of master cylinder may be reduced.

Summary of the invention

Therefore, the object of the invention is to the manufacture efficiency improving master cylinder.

In order to reach above-mentioned purpose, the master cylinder described in first aspect of the invention, it has: piston slides and produces the oil cylinder of pressure; To the fuel tank of described oil cylinder supply working fluid; To be arranged on described oil cylinder and to connect the tubular connecting portion of described fuel tank; Be arranged on described fuel tank and the tubular insertion section of inserting in described connecting portion; To be arranged between described connecting portion and described insertion section and to there is elasticity and seal the sealing element of the tubular between described connecting portion and insertion section, it is characterized in that, described insertion section has the flange part to radial outside expansion in front, described connecting portion has: the front of the side face that sets within it and the first inside diameter of the diameter ring-type larger than the external diameter of described flange part; Be arranged on the base end side of this first inside diameter and diameter second inside diameter larger than the diameter of this first inside diameter; Be positioned at the base end side of this second inside diameter and diameter three inside diameter larger than the diameter of this second inside diameter, described sealing element has: the base end part that the diameter abutted with the front end face of described connecting portion is large; The fitting portion of the ring-type chimeric with the first inside diameter of described connecting portion; The sealed chamber portion abutted with on position that is described base end part opposite side vertically and with the second inside diameter of described insertion section and described connecting portion that is that be arranged on this fitting portion.

Master cylinder described in second aspect of the invention, is characterized in that, described sealing element, at its outer peripheral face, is provided with the diameter protrusion larger than the diameter in sealing cylinder portion at the leading section in described sealed chamber portion.

Master cylinder described in third aspect of the invention, is characterized in that, described 3rd inside diameter of described connecting portion has the reducing diameter part reducing diameter to described second inside diameter gradually.

Master cylinder described in fourth aspect of the invention, is characterized in that, being set at least partially of described protrusion contacts with described second inside diameter in a state of use.

Master cylinder described in fifth aspect of the invention, it is characterized in that, described connecting portion has footpath four inside diameter less than the diameter of described first inside diameter, and the 4th inside diameter is positioned at the base end side of described 3rd inside diameter and be arranged on can on the position relative with described flange part.

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

Accompanying drawing explanation

Fig. 1 is the lateral plan of the main portion representing the master cylinder of the first embodiment with section.

Fig. 2 is the close-up sectional view of the connecting portion of the master cylinder representing the first embodiment.

Fig. 3 is the figure of the sealing element of the master cylinder representing the first embodiment, Fig. 3 (a) is section drawing, and Fig. 3 (b) is front view.

Fig. 4 is the close-up sectional view of the insertion section of the master cylinder representing the first embodiment.

Fig. 5 (a) ~ (c) is the close-up sectional view of the number of assembling steps representing the master cylinder of the first embodiment according to the order of (a) ~ (c).

Fig. 6 is the figure of the sealing element of the master cylinder representing the second embodiment, Fig. 6 (a) is section drawing, and Fig. 6 (b) is front view.

Fig. 7 (a) ~ (d) is the close-up sectional view of the number of assembling steps representing the master cylinder of the second embodiment according to the order of (a) ~ (d).

Fig. 8 is the close-up sectional view of the connecting portion of the master cylinder representing the 3rd embodiment.

Fig. 9 (a) ~ (b) is the close-up sectional view of the number of assembling steps representing the master cylinder of the 3rd embodiment according to the order of (a) ~ (b).

Description of reference numerals

12 fuel tanks

13,13A sealing element

17 oil cylinders

21,22 pistons

28,28B connecting portion

34 insertion sections

35 front end faces

38 fitting projection

39 central diameter portions

40,40B large-diameter portion

41,41B minor diameter part

53 conical surface portions (reducing diameter part)

68 base end parts

69 chimeric recesses

70,70A sealed chamber portion

114 flange parts

131 protrusions

Detailed description of the invention

Below, the master cylinder of the embodiments of the present invention is described.

" the first embodiment "

Be described with reference to the master cylinder of Fig. 1 ~ Fig. 5 to the first embodiment.As shown in Figure 1, this master cylinder there is master cylinder main body 11, be arranged on plastic fuel tank 12 on the upside of the vertical direction of master cylinder main body 11 integratedly, the sealing element 13,13 of a pair rubber in gap between sealing master cylinder main body 11 and fuel tank 12.Master cylinder main body 11 produces the operating oil pressure of the operational ton corresponding to not shown brake pedal, and is supplied by its Of Wheel Brake Oil-Cylinders to the plate disc brake be arranged on wheel or drum brake mechanism etc.Fuel tank 12 stores working oil (working fluid) and it is supplied to master cylinder main body 11 as required.

Master cylinder main body 11 has the oil cylinder 17 having bottom tube-like, and this oil cylinder 17 has bottom 15 and from the circumference of bottom 15 along its axially extended cylinder portion 16.This oil cylinder 17 is made up of metals such as aluminum alloys, and to make length direction mounted on a vehicle along the attitude of the fore-and-aft direction of such as vehicle.

Master cylinder main body 11 has: main piston (piston) 21, and it can be slidably inserted into the side contrary with the bottom 15 in oil cylinder 17; Auxiliary piston (piston) 22, it can be slidably inserted into the side, bottom 15 in oil cylinder 17.In oil cylinder 17, mark off secondary stress room 23 by the bottom 15 of auxiliary piston 22, oil cylinder 17 and cylinder portion 16.Further, in oil cylinder 17, main pressure chamber 24 is marked off by the cylinder portion 16 of auxiliary piston 22, main piston 21 and oil cylinder 17.And, although not shown, but be provided with the gap-forming portion comprising spring between auxiliary piston 22 and the bottom 15 of oil cylinder 17, this gap-forming portion, under the non-brake state not from the input of brake pedal, determines the interval between above-mentioned auxiliary piston 22 and the bottom 15 of oil cylinder 17.In addition, be also provided with the gap-forming portion comprising spring between auxiliary piston 22 and main piston 21, this gap-forming portion, under non-brake state, determines the interval between above-mentioned auxiliary piston 22 and main piston 21.

And, in master cylinder main body 11, when the operation by not shown brake pedal makes main piston 21 to auxiliary piston 22 Slideslip, the pressure increase of the main pressure chamber 24 in oil cylinder 17.By the Of Wheel Brake Oil-Cylinders transmission that the pressure of this rising links to the drg pipe arrangement with a system.In addition, by the slip of this main piston 21, make auxiliary piston 22 to bottom 15 Slideslip of oil cylinder 17 via not shown gap-forming portion.Thus, the pressure increase of the secondary stress room 23 in oil cylinder 17, and by Of Wheel Brake Oil-Cylinders transmission that this pressure links to the drg pipe arrangement with another system.That is, by making main piston 21 and auxiliary piston 22 slide, oil cylinder 17 produces the pressure transmitted to Of Wheel Brake Oil-Cylinders.

Oil cylinder 17 is provided with side by side a pair connecting portion 28,28 that fuel tank 12 is connected with oil cylinder 17.Above-mentioned connecting portion 28,28 is integrally formed in the axial midway location in a portion 16 in the mode that the radial outside to cylinder portion 16 is outstanding.Above-mentioned connecting portion 28,28 matches each other in the position of the circumferencial direction in cylinder portion 16 and axis along cylinder portion 16 is formed separately before and after, be formed with the connecting bore 29 of the radial direction in the cylinder portion 16 along oil cylinder 17 respectively in inner side, thus form the tubular along the radial direction in the cylinder portion 16 of oil cylinder 17.

Fuel tank 12 comprises: the lid 32 that can load and unload with the fuel tank main body 31 of liquid supply mouth 30, opening and closing liquid supply mouth 30.Fuel tank main body 31 has: for the aforesaid liquid supply mouth 30 from outside supply working oil; Be positioned at the downside of liquid supply mouth 30 and store the container part 33 of working oil; Be located at the downside of container part 33 side by side and in a pair connecting portion 28,28 being inserted into oil cylinder 17, supply a pair insertion section 34,34 of working oil to oil cylinder 17.Above-mentioned insertion section 34,34 is in the tubular be parallel to each other and be integrally formed with fuel tank main body 31.Specifically, be formed as from container part 33 to contrary with liquid supply mouth 30 one example, that is, outstanding below vertical direction.

An insertion section 34 of fuel tank 12 is connected with a connecting portion 28 of oil cylinder 17 via a sealing element 13.In addition, another insertion section 34 of fuel tank 12 is connected with another connecting portion 28 of oil cylinder 17 via another sealing element 13.Therefore, the working oil that a pair connecting portion 28,28 acceptance that master cylinder main body 11 passes through its oil cylinder 17 supplies from fuel tank 12.A pair sealing element 13,13 forms roughly tubular, and is arranged on separately between corresponding connecting portion 28 and the insertion section 34 be inserted therein.A pair sealing element 13,13 has elasticity, seals the gap between respective connecting portion 28 and insertion section 34.

The structure be arranged on a connecting portion 28 of above-mentioned oil cylinder 17 insertion section 34 via a sealing element 13 is identical with the structure be arranged on another connecting portion 28 another insertion section 34 via another sealing element 13.Therefore, below, with reference to Fig. 2 ~ Fig. 5, a connecting portion 28, sealing element, 13, insertion section 34 and their connected structure are described in detail.

First, the connecting portion 28 of oil cylinder 17 is described.As shown in Figure 2, the open end of connecting portion 28, is namely formed as vertical with connecting bore 29 smooth circular with the front end face 35 of cylinder portion 16 opposite end.In addition, the cardinal extremity example bottom surface 36 of the side, cylinder portion 16 of connecting portion 28 is formed as the smooth circle vertical with connecting bore 29.

And the inner peripheral surface of connecting portion 28 has fitting projection 38, central diameter portion 39, large-diameter portion 40, minor diameter part 41.Fitting projection 38 (the first inside diameter) the open side of connecting portion 28 and front end face 35 side be formed as giving prominence to the inside circular.Central diameter portion 39 (the second inside diameter) is arranged adjacently at the side, cylinder portion 16 of the axis of fitting projection 38 and base end side and fitting projection 38, and has the internal diameter size larger than the internal diameter of fitting projection 38.Side, cylinder portion 16 and the central diameter portion 39 of large-diameter portion 40 (the 3rd inside diameter) axis in central diameter portion 39 are arranged adjacently, and have the internal diameter size larger than the internal diameter in central diameter portion 39.Minor diameter part 41 (the 4th inside diameter) is arranged adjacently in the side, cylinder portion 16 of the axis of large-diameter portion 40 and large-diameter portion 40, and it is less than the internal diameter size of any one in fitting projection 38, central diameter portion 39 and large-diameter portion 40 to be formed as internal diameter size.

Fitting projection 38 has front-end-cone face 44, front cylinder face 45, conelet face 46 and step face 47.

Front-end-cone face 44 is formed as from the Inner peripheral portions of front end face 35 more to the taper that cylinder portion 16 side diameter is less, and extends to side, cylinder portion 16.Front cylinder face 45 extends from the end edge portion of the side, cylinder portion 16 in conical surface portion, front end 44 with certain side, diametrically cylinder portion 16.Conelet face 46 is formed as from the end edge portion of cylinder portion 16 example in barrel surface portion, front 45 more to the taper that cylinder portion 16 side diameter is larger, and extends to side, cylinder portion 16.Step face 47 be formed as from the end edge portion of the side, cylinder portion 16 of conelet face 46 to radial outside with one fixed width expand circular.

Central diameter portion 39 has middle cylinder face 50, and this middle cylinder face 50 extends from the end edge portion of the side, large footpath of step face 47 with certain side, diametrically cylinder portion 16.The diameter of this middle cylinder face 50 is larger than the diameter of front cylinder face 45.

Large-diameter portion 40 has conical surface portion 53 (reducing diameter part), bending face 54, conical surface portion 55.

Conical surface portion 53 is formed as from the end edge portion of the side, cylinder portion 16 in middle barrel surface portion 50 more to the taper that cylinder portion 16 side diameter is larger, and extends to side, cylinder portion 16.That is, the conical surface portion 53 of large-diameter portion 40 is towards central diameter portion 39 reduced diameter.Bending face 54 is from the end edge portion of the side, cylinder portion 16 in conical surface portion 53 with more to after cylinder portion 16 side diameter is larger, and more to the less mode of cylinder portion 16 side diameter to the extension of side, cylinder portion 16, and the cross sectional shape comprising the cross section of the central axis of connecting bore 29 is arc-shaped.

Conical surface portion 55 be formed as from bending facial 54 the end edge portion of side, cylinder portion 16 more to the taper that cylinder portion 16 side diameter is less, and to extend to side, cylinder portion 16.The minimum diameter in conical surface portion 55 is less than the diameter of front cylinder facial 45 and middle cylinder face 50, and the large diameter portion being more than or equal to the diameter of middle cylinder face 50 in conical surface portion 55 forms large-diameter portion 40.That is, conical surface portion 55 is with the intersection position of the elongated surfaces of itself and middle cylinder face 50 for border, and bending facial 54 sides form large-diameter portions 40, forms minor diameter part 41 with bending facial 54 contrary sides.

Minor diameter part 41 has the diameter part less than the diameter of the middle cylinder face 50 in above-mentioned conical surface portion 55, base end side cylinder face 58, base end side conical surface portion 59.

Base end side cylinder face 58 extends from the end edge portion of the side, cylinder portion 16 in conical surface portion 55 with certain side, diametrically cylinder portion 16.Therefore, the diameter of base end side cylinder face 58 is less than the diameter of middle cylinder face 50, less than the diameter of front cylinder face 45, and the diameter of minor diameter part 41 is less than the diameter of fitting projection 38.Base end side conical surface portion 59 is formed as from the end edge portion of the side, cylinder portion 16 of base end side cylinder face 58 more to the taper that cylinder portion 16 side diameter is less, and extends to side, cylinder portion 16, is connected with cardinal extremity face 36.

Be formed with fillet surface 60 at the outer circumferential side of the open end of connecting portion 28, this fillet surface 60 is more larger to cylinder portion 16 side diameter vertically from the end edge portion of the outer circumferential side of front end face 35.

In addition, above-mentioned front end face 35, fillet surface 60, front-end-cone face 44, front cylinder face 45, conelet face 46, step face 47, middle cylinder face 50, conical surface portion 53, bending face 54, conical surface portion 55, base end side cylinder face 58 are all consistent with the central axis in base end side conical surface portion 59.Therefore, the central axis of fitting projection 38, pars intermedia 39, large-diameter portion 40 and minor diameter part 41 is also all consistent, and its central axis is the central axis of connecting bore 29.

Then, to be in chimeric with the connecting portion 28 of oil cylinder 17 before namely insert the insertion section 34 of fuel tank 12 before the sealing element 13 of rubber of state of nature be described.As shown in Figure 3, sealing element 13 is in tubular, and the path end face 64 of the bigger diameter end face 63 of axial one end and the diameter axial other end little than it is formed as the even shape along the expansion of square with the axis direction.

Have at the outer peripheral face of sealing element 13: the circular base end part 68 that diameter is large; Circular chimeric recess 69 (fitting portion), it is arranged adjacently with base end part 68 in the axial direction, and caves in radially inner side in the mode that minimum diameter is less than the diameter of base end part 68.In addition, also have the sealed chamber portion 70 of tubular, it is arranged on an example contrary with base end part 68 of chimeric recess 69 vertically adjacently, and diameter is larger and less than the diameter of base end part 68 than the minimum diameter of chimeric recess 69.

Base end part 68 has end side cylinder face 73, end side step face 74, middle cylinder face 75 and intermediate step face 76.

End side cylinder face 73 extends from the edge, periphery in bigger diameter end face 63 with certain diametrically path end face 64 side.End side step face 74 be formed as from the end edge portion of path end face 64 side of end side cylinder face 73 to radially inner side with one fixed width expand circular.

Middle cylinder face 75 extends from the end edge portion of the path side of end side step face 74 with certain diametrically path end face 64 side.Therefore, the diameter of middle cylinder face 75 is less than the diameter of end side cylinder face 73.Intermediate step face 76 be formed as from the end edge portion of path end face 64 side in middle barrel surface portion 75 to radially inner side with one fixed width expand circular.

At this, the minimum diameter of base end part 68 is larger than the external diameter of the open side end of the connecting portion 28 shown in Fig. 2.That is, any one in the diameter of the end side cylinder face 73 of base end part 68, end side step face 74 and middle cylinder face 75 is all large than the external diameter of the front end face 35 of connecting portion 28, and larger than the external diameter of fillet surface 60.

Chimeric recess 69 has: a part for the path side of intermediate step face 76; Bending face 79; Most path barrel surface portion 80; Bending face 81; Other end side stage terrace portion 82.

Bend the end edge portion of face 79 from the path side in middle step surface portion 76 more to extend to the mode that path end face 64 side diameter is less to path end face 64 side, and the shape comprising the cross section of the central axis of sealing element 13 is arc-shaped.

Most path barrel surface portion 80 extends from the end edge portion of the path side of bending facial 79 with certain diametrically path end face 64 side.Thus the diameter in most path barrel surface portion 80 is less than the diameter of end side cylinder facial 73 and middle cylinder face 75.

Bending face 81 is from the end edge portion of path end face 64 side in most path barrel surface portion 80 more to extend to the mode that path end face 64 side diameter is larger to path end face 64 side, and the shape comprising the cross section of the central axis of sealing element 13 is arc-shaped.Other end side stage terrace portion 82 be formed as from bending facial 81 path end face 64 side end edge portion to radial outside with one fixed width expand circular.

At this, the minimum outer diameter of chimeric recess 69 is larger than the minimum diameter of the fitting projection 38 of the connecting portion 28 shown in Fig. 2.That is, the diameter in the most path barrel surface portion 80 of chimeric recess 69 is larger than the diameter of the front cylinder face 45 of fitting projection 38.In addition, the axial width of chimeric recess 69 is wider than the axial length of the fitting projection 38 of connecting portion 28.That is, the axial distance between the intermediate step face 76 of chimeric recess 69 and other end side stage terrace portion 82 is longer than the axial distance between the front end face 35 of connecting portion 28 and step face 47.

Sealed chamber portion 70 is formed with the identical rib 85,86 of two external diameters and between them and the external diameter rib 87 less than their external diameter.Sealed chamber portion 70 has the convex surface part 88 of the outside face forming rib 85, the convex surface part 89 forming the outside face of rib 87, the convex surface part 90 forming the outside face of rib 86, another barrel surface portion, side 91, another conical surface portion, side 92.

Convex surface part 88, more to reduce diameter to the mode that path end face 64 side diameter is less and extends to path end face 64 side from the end edge portion of the outside diameter in other end side stage terrace portion 82 with more after the larger mode enlarged of path end face 64 side diameter.The shape comprising the cross section of the central axis of sealing element 13 of convex surface part 88 is arc-shaped.

Convex surface part 89, more to reduce diameter to the mode that path end face 64 side diameter is less and extends to path end face 64 side from the end edge portion of path end face 64 side of convex surface part 88 with more after the larger mode enlarged of path end face 64 side diameter.The shape comprising the cross section of the central axis of sealing element 13 of convex surface part 89 is also in arc-shaped.

Convex surface part 90, more to reduce diameter to the mode that path end face 64 side diameter is less and extends to path end face 64 side from the end edge portion of path end face 64 side of convex surface part 88 with more after the larger mode enlarged of path end face 64 side diameter.The shape comprising the cross section of the central axis of sealing element 13 of convex surface part 90 is also in arc-shaped.

Another barrel surface portion, side 91 extends from the end edge portion of path end face 64 side of convex surface part 90 with certain diametrically path end face 64 side.Another conical surface portion, side 92 from the end of path end face 64 side in another barrel surface portion, side 91 being more that taper extends and is connected with path end face 64 to the less mode of path end face 64 side diameter to path end face 64 side.

The maximum outside diameter in sealed chamber portion 70 is larger than the diameter in the central diameter portion 39 of connecting portion 28.That is, the external diameter of the convex surface part 88,90 in sealed chamber portion 70 is larger than the diameter of the middle cylinder face 50 of connecting portion 28.

The axial length in sealed chamber portion 70 is longer than the axial length in the central diameter portion 39 of connecting portion 28, and with by central diameter portion 39 and large-diameter portion 40 axial length altogether roughly equal.In other words, the axial length in sealed chamber portion 70 is shorter than the central diameter portion 39 of connecting portion 28, large-diameter portion 40 and minor diameter part 41 axial length altogether.Axial length between the other end side stage terrace portion 82 in sealed chamber portion 70 and path end face 64 equals the axial length between the intersection position of the elongated surfaces of the step face 47 of connecting portion 28 and the middle cylinder face 50 in conical surface portion 55, and shorter than the axial length between the step face 47 of connecting portion 28 and the end of base end side cylinder face 58 sides in conical surface portion 55.

Be formed multiple in the inner peripheral portion of sealing element 13, specifically two roots 95,96.The inner peripheral surface of sealing element 13 has end side conical surface portion 99, end side step face 100, end side bend face 101, end side cylinder face 102, the convex surface part 103 forming the outside face of rib 95, middle cylinder face 104, the convex surface part 105 forming the outside face of rib 96, another barrel surface portion, side 106.

End side conical surface portion 99 is formed as from the Inner peripheral portions in bigger diameter end face 63 more to the taper that path end face 64 side diameter is less, and extends to path end face 64 side.End side step face 100 be formed as from the end edge portion of path end face 64 side in end side conical surface portion 99 to radially inner side with one fixed width expand circular.End side bends the Inner peripheral portions of face 101 from end side step face 100 more to extend to the mode that path end face 64 side diameter is less to path end face 64 side, and the shape comprising the cross section of the central axis of sealing element 13 is arc-shaped.End side cylinder face 102 extends from the end edge portion of path end face 64 side in end side conical surface portion 99 with certain diametrically path end face 64 side.

Convex surface part 103, more to reduce diameter to the mode that path end face 64 side diameter is less and extends to path end face 64 side from the end edge portion of path end face 64 side of end side cylinder face 102 with more after the larger mode enlarged of path end face 64 side diameter.The shape comprising the cross section of the central axis of sealing element 13 of convex surface part 103 is arc-shaped.Middle cylinder face 104 extends from the end edge portion of path end face 64 side of convex surface part 103 with certain diametrically path end face 64 side identical with end side cylinder face 102.Convex surface part 105, more to reduce diameter to the mode that path end face 64 side diameter is less and extends to path end face 64 side from the end edge portion of path end face 64 side in middle barrel surface portion 104 with more after the larger mode enlarged of path end face 64 side diameter.The shape comprising the cross section of the central axis of sealing element 13 of convex surface part 105 is arc-shaped.

Another barrel surface portion, side 106 extends from the end edge portion of path end face 64 side of convex surface part 105 with certain diametrically path end face 64 side identical with middle cylinder face 104 with end side cylinder face 102, and is connected with path end face 64.

The bigger diameter end face 63 of sealing element 13, path end face 64, end side cylinder face 73, end side step face 74, middle cylinder face 75, intermediate step face 76, bending face 79, most path barrel surface portion 80, bending face 81, other end side stage terrace portion 82, convex surface part 88, convex surface part 89, convex surface part 90, another barrel surface portion, side 91, another conical surface portion, side 92, end side conical surface portion 99, end side step face 100, the bending face 101 of end side, end side cylinder face 102, convex surface part 103, middle cylinder face 104, convex surface part 105, the central axis in another barrel surface portion, side 106 is all consistent, and be the central axis of sealing element 13.Middle cylinder face 104, convex surface part 105 and another barrel surface portion, side 106 form the inner peripheral surface in sealed chamber portion 70.

Then, the insertion section 34 that the synthetic resin higher than the rigidity of sealing element 13 by rigidity is formed is described.As shown in Figure 4, be formed with the housing recess 110 caved in upward at the lower surface of the container part 33 of fuel tank main body 31, and insertion section 34 is given prominence to along the direction that vertical direction is downward from the mediad of this housing recess 110.In addition, housing recess 110 has: orthogonal with the central axis of insertion section 34 circular bottom surface sections 111, from the end edge portion of the side, large footpath of bottom surface sections 111 be orthogonal with bottom surface sections 111 and the cylinder face 112 of the certain diameter extended downwards.

Insertion section 34 is formed as having cylindric cylindrical portion 113 and the shape of flange part 114.Cylindrical portion 113 extends with roughly certain diameter near front end from the bottom surface sections 111 of housing recess 110, and flange part 114 extends from the front contrary with housing recess 110 of cylindrical portion 113 to radial outside.

Cylindrical portion 113 be certain with the diameter of the inner peripheral surface 116 is communicated with in container part 33, its outer peripheral face has an end and bends facial 117 and main cylinder face 118.The end, bends face 117 and is in the position with the border of the bottom surface sections 111 of housing recess 110, and more to extend to the mode that flange part 114 side diameter is less to flange part 114 side, and the shape comprising the cross section of the central axis of insertion section 34 is arc-shaped.Main cylinder face 118 bends the path side of the face 117 end edge portion end of from vertically extends with certain diameter and bottom surface sections 111.The front end face 119 contrary with bottom surface sections 111 of cylindrical portion 113 is parallel with bottom surface sections 111.

Flange part 114 has locking step face 120, locking cylinder face 121, front-end-cone face 122.Locking step face 120 be formed as from the end edge portion of front end face 119 side of main cylinder face 118 to radial outside with one fixed width expand circular.Locking cylinder face 121 extends from the end edge portion of the outside diameter of locking step face 120 with certain diametrically front end face 119 side.Front-end-cone face 112 extends end face 119 side forward from the end edge portion of front end face 119 side of locking cylinder face 121 in the mode that end face 119 side diameter is more forward less, and is connected with front end face 119.

Inner peripheral surface 116, the end, bend face 117, main cylinder face 118, locking step face 120, locking cylinder face 121, front-end-cone face 122 are all consistent with the central axis of front end face 119, and are the central axis of insertion section 34.The central axis of insertion section 34 is also consistent with the bottom surface sections 111 of housing recess 110 and the central axis of cylinder face 112, and orthogonal with the bottom surface sections 111 of housing recess 110.

At this, the axial length except flange part 114 scope of insertion section 34, that is, the end, bends the axial length of face 117 and main cylinder face 118, in other words, the axial length between bottom surface sections 111 and locking step face 120 is longer than the entire axial length of sealing element 13.In addition, the equal diameters in one end example cylinder face 102 of the diameter of the main cylinder face 118 of insertion section 34 and sealing element 13, middle cylinder face 104 and another barrel surface portion, side 106, and larger than the minimum diameter of convex surface part 103,105.In addition, the external diameter of flange part 114, that is, engage the end side cylinder face 102 of diameter than sealing element 13 of cylinder face 121, middle cylinder face 104 and another barrel surface portion, side 106 diameter large.In addition, the front-end-cone face 122 of flange part 114 minimum diameter than the end side of sealing element 13 bend face 101 maximum gauge little.In addition, the maximum outside diameter of the base end part 68 of the maximum gauge of housing recess 110 and the diameter of cylinder face 112 and sealing element 13 and the equal diameters of end side cylinder face 73.

The diameter that namely external diameter of the flange part 114 of insertion section 34 engages cylinder face 121 than the internal diameter of the fitting projection 38 of the ring-type of connecting portion 28 and the diameter of front cylinder face 45 little.In other words, the fitting projection 38 being arranged at the front of the inner peripheral surface of connecting portion 28 is formed as the diameter ring-type larger than the external diameter of flange part 114.

Then, to the connected structure of connecting portion 28, sealing element 13 and insertion section 34, be described according to its engagement step.

First, as shown in Fig. 5 (a), make sealing element 13 chimeric with connecting portion 28.Now, make the sealed chamber portion 70 of sealing element 13 and the central diameter portion 39 of connecting portion 28 and large-diameter portion 40 in an interference fit (Parties め is for The も つ) chimeric, and the fitting projection 38 of connecting portion 28 is fitted together in an interference fit with the chimeric recess 69 of sealing element 13.In addition, its base end part 68 is made to abut with the front end face 35 of connecting portion 28.Specifically, the intermediate step face 76 of the sealing element 13 shown in Fig. 3 abuts with the front end face 35 of the connecting portion 28 shown in Fig. 2, the most path barrel surface portion 80 of the sealing element 13 shown in Fig. 3 abuts with the front cylinder face 45 of the connecting portion 28 shown in Fig. 2, and the other end side stage terrace portion 82 of the sealing element 13 shown in Fig. 3 abuts with the step of the connecting portion 28 shown in Fig. 2 facial 47.In addition, the convex surface part 88 of the sealing element 13 shown in Fig. 3 and convex surface part 89 produce distortion, abut with the middle cylinder face 55 of the connecting portion 28 shown in Fig. 2, convex surface part 90 and another barrel surface portion, side 91 of the sealing element 13 shown in Fig. 3 are out of shape, abut with the conical surface portion 53 of the connecting portion 28 shown in Fig. 2, bending face 54 and conical surface portion 55, another conical surface portion, side 92 of the sealing element 13 shown in Fig. 3 abuts with the conical surface portion 55 of the connecting portion 28 shown in Fig. 2.

Then, as Fig. 5 (a) to Fig. 5 (b), arrive shown in Fig. 5 (c) further, the insertion section 34 of fuel tank main body 31 is inserted into and is held in the sealing element 13 of connecting portion 28.Now, first, insertion section 34 face 101 bending with the end side of sealing element 13 on the front-end-cone face 122 of the flange part 114 of the front such as shown in Fig. 5 (a) abuts, afterwards, the locking cylinder face 121 of flange part 114 contacts with the bending face 101 of the end side of sealing element 13, end side cylinder face 102, convex surface part 103, middle cylinder face 104, convex surface part 105, another barrel surface portion, side 106 in turn, while these contact portions and neighbouring part thereof, are fitted together to radial outside crimp to axial tension.Now, as shown in Fig. 5 (b), allow sealing element 13 to be out of shape further to radial outside at the large-diameter portion 40 (the 3rd inside diameter) in the front in central diameter portion 39 (the second inside diameter), the sliding resistance that flange part 114 applies is weakened.In addition, the part of the sealing element 13 be out of shape laterally because of being extruded by flange part 114 is accommodated in large-diameter portion 40 (the 3rd inside diameter), so the overhang to direction of insertion front of the resistance becoming flange part 114 can be suppressed, according to this point, the sliding resistance that flange part 114 is applied also can be weakened.Like this, in the present embodiment, owing to having large-diameter portion 40 (the 3rd inside diameter), even if so arrange flange part 114 on insertion section 34, also there will not be the situation being difficult to be assembled in by fuel tank 12 in master cylinder main body 11.

Then, when such as making flange part 114 exceed sealing element 113 shown in Fig. 5 (c), sealing element 13 and insertion section 34 close contact in an interference fit.Namely, when being inserted exactly insertion section 34 in the sealing element 13 being held in connecting portion 28, the end side cylinder face 102 of the inner circumferential side of the sealing element 13 shown in Fig. 3, convex surface part 103, middle cylinder face 104, convex surface part 105 and another barrel surface portion, side 106 abut with the main cylinder face 118 of the insertion section 34 shown in Fig. 4 in an interference fit.Now, the sealed chamber portion 70 of the outer circumferential side of sealing element 13 abuts in an interference fit with the central diameter portion 39 of connecting portion 28 and large-diameter portion 40.

In addition, now, as shown in Fig. 5 (c), the base end part 68 of sealing element 13 is incorporated in the housing recess 110 of fuel tank main body 31.That is, the bigger diameter end face 63 of the sealing element 13 shown in Fig. 3 abuts with the bottom surface sections 111 of the housing recess 110 shown in Fig. 4, and the end side cylinder face 73 of the sealing element 13 shown in Fig. 3 abuts with the cylinder face 112 of the housing recess 110 shown in Fig. 4.

In addition, now, as shown in Fig. 5 (c), flange part 114 leaves the path end face 54 of sealing element 13, and overlaps with minor diameter part 41 axial location of connecting portion 28 and diametrically.In other words, the minor diameter part 41 of connecting portion 28 is arranged on position that can be relative with flange part 114.In addition, the position of flange 114 is inserted into the position of sealing element 13 according to the deflection of base end part 68 and insertion section 34 and front and back change, according to different positions, the position of flange part 114 may be made to be in radially not relative with the base end side cylinder face 58 of the minor diameter part 41 of connecting portion 28 state, but, if insert insertion section 34 until at least utilize housing recess 110 and connecting portion 28 to compress base end part 68, flange part 114 just can be made to be in and to overlap and radially relative state at axial location with the base end side cylinder face 58 of connecting portion 28.

At this, in the technology described in above-mentioned patent documentation 1, be provided with to the outstanding claw in internal diameter side in the front end of the connecting portion (lug boss) of master cylinder main body, sealing element is provided with cylindrical portion that is outstanding to external diameter side and that engage with the axis of claw inner side, and the leading section of the insertion section (connected legs) of fuel tank is provided with the flange part to outside diameter expansion, and the axis of this flange part and sealing element inner side is engaged.Under the above structure, depart from from lug boss to limit connected legs, need the elongation increasing flange part, but, when increasing the elongation of flange part, needing to make the sealing element contacted with the inner peripheral surface of lug boss produce larger distortion, the assembleability of fuel tank and master cylinder main body is declined, and then, manufacture efficiency and decline.Therefore, in the technology described in patent documentation 1, by making flange part eccentric, coming off when particularly seeking the vacuum fill limiting working oil, and improve assembleability.But, in the technology described in patent documentation 1, can fully limit connected legs hardly and come off from lug boss.On the other hand, come off from lug boss to improve assembleability and limiting connected legs, by pin, fuel tank and master cylinder main body are linked, thus fuel tank can be held in master cylinder main body, but if use pin, then number of components increases, and number of assembling steps increases.

To this, the master cylinder of the first embodiment is on the connecting portion 28 of master cylinder main body 11, the base end side of fitting projection 38 is provided with the diameter central diameter portion 39 larger than its diameter, the base end side in this central diameter portion 39 is provided with the diameter large-diameter portion 40 larger than the diameter in this central diameter portion 39.Thus, when making the flange part 114 to radial outside extension of the insertion section 34 of fuel tank main body 31 chimeric with the sealing element 13 utilizing the central diameter portion 39 of connecting portion 28 to engage, if sealing element 13 is extruded by flange part 114, large-diameter portion 40 allows sealing element 13 to the larger distortion of radial direction.Thus, the sliding resistance of sealing element 13 relative to insertion section 34 is weakened.In addition, the part of being out of shape laterally because sealing element 13 is extruded by flange part 114 is incorporated in large-diameter portion 40, so suppress the overhang to direction of insertion front as the resistance of flange part 114, according to this point, also weaken the sliding resistance that flange part 114 is applied.Therefore, though increase flange part 114 radial elongation thus when working oil filling etc. restriction insertion section 34 come off from connecting portion 28, also can realize the good assembleability of fuel tank 12 and oil cylinder 17, and manufacture efficiency can be improved.Therefore, even if do not adopt the structure utilizing pin to link fuel tank 12 and oil cylinder 17, and adopt by means of only insertion section 34 to be inserted the structure carrying out in connecting portion 28 linking via sealing element 13, also can limit insertion section 34 and come off from connecting portion 28.

In addition, due to connecting portion 28 at above-mentioned large-diameter portion 40 more by base end side, in mode that can be relative with flange part 114, there is the diameter minor diameter part 41 less than the diameter of fitting projection 38, so such as, even if sealing element 13 is stretched more than anticipation by flange part 114, also can limit sealing element 13 enters between flange part 114 and minor diameter part 41, can suppress the damage of sealing element 13.

In addition, because the large-diameter portion 40 of connecting portion 28 has the conical surface portion 53 reducing diameter to central diameter portion 39 gradually, so the pressure of working oil when utilizing filling operation oil, the insertion section 34 of fuel tank main body 31 is moved to extracting direction, flange part 114 abut with the path end face 64 of sealing element 13 and by sealing element 13 to extract direction extrude time, sealed chamber portion 70 is out of shape and the gap closed between itself and insertion section 34 to produce to the mode of radially inner side movement by the guiding in conical surface portion 53, improves the contact between insertion section 34 and increasing friction force.Thereby, it is possible to restriction extracts insertion section 34 from connecting portion 28 further.

" the second embodiment "

Then, mainly the master cylinder of the second embodiment is described centered by the part different from the first embodiment based on Fig. 6 with Fig. 7.In addition, identical with the first embodiment part uses same title, prosign represents.

In this second embodiment, the sealing element 13A with the sealed chamber portion 70A different relative to the local, sealed chamber portion 70 of the sealing element 13 of the first embodiment is used.The sealing element 13A of the second embodiment does not arrange the rib 86 of the first embodiment, but it is larger than the diameter of sealed chamber portion 70A that the leading section of the sealed chamber portion 70A of its outer peripheral face is provided with diameter, that is, larger than the diameter of rib 85 circular protrusion 131.That is, sealed chamber portion 70A has: the convex surface part 88 forming the outside face of rib 85; Form the convex surface part 89 of the outside face of rib 87; Form the step face 132 of the outside face of protrusion 131, bending face 133 and conical surface portion 134.

Step face 132 is expanded to radial outside from the end edge portion of path end face 64 side of convex surface part 88 along direction orthogonal to the axis.The end edge portion of bending face 133 in the side, large footpath from step face 132, with more after the larger mode enlarged of path end face 64 side diameter, reduces diameter in the mode more diminished to path end face 64 side diameter, and extends to path end face 64 side.The shape comprising the cross section of the central axis of sealing element 13A of bending face 133 is arc-shaped.The end edge portion of path end face 64 side of conical surface portion 134 from bending facial 133, more to reduce diameter to the mode that path end face 64 side diameter is less and to extend to path end face 64 side, is connected with path end face 64.

The maximum outside diameter of sealed chamber portion 70A and the maximum outside diameter of protrusion 131 larger than the external diameter in the central diameter portion 39 of connecting portion 28.In addition, when the volume of protrusion 131 be V1, the sealing of the inner side of large-diameter portion 40 to keep out of the way spatial volume be V2 time, be set as V1 < V2.And, axial length between the intermediate step face 76 of base end part 68 and the maximum outside diameter position of protrusion 131 is shorter than the axial length between the front end face 35 of connecting portion 28 and the maximum inner diameter position of large-diameter portion 40, axial length between the intermediate step face 76 of base end part 68 and the step face 132 of protrusion 131 than connecting portion 28 front end face 35 with, the axial length between the position, boundary of central diameter portion 39 and large-diameter portion 40 is short.That is, the protrusion 131 of sealed chamber portion 70A overlaps position in the axial direction with the central diameter portion 39 of connecting portion 28.

Then, the connected structure between connecting portion 28, sealing element 13A, insertion section 34 is described according to its engagement step.

First, as shown in Fig. 7 (a), sealing element 13A is chimeric with connecting portion 28.Now, sealing element 13A makes the protrusion 131 of its sealed chamber portion 70A abut with the central diameter portion 39 of connecting portion 28, and the fitting projection 38 of connecting portion 28 recess 69 chimeric with it is fitted together to, and its base end part 68 abuts with the front end face 35 of connecting portion 28.Specifically, the intermediate step face 76 of the sealing element 13A shown in Fig. 6 abuts with the front end face 35 of the connecting portion 28 shown in Fig. 2, the most path barrel surface portion 80 of the sealing element 13A shown in Fig. 6 abuts with the front cylinder face 45 of the connecting portion 28 shown in Fig. 2, and bending facial 133 of the sealing element 13 shown in Fig. 6 abut with the middle cylinder facial 50 of the connecting portion 28 shown in Fig. 2.

Then, as Fig. 7 (a) to Fig. 7 (b), arrive shown in Fig. 7 (c), 7 (d) further, the insertion section 34 of fuel tank main body 31 is inserted and is held in the sealing element 13A of connecting portion 28.Now, first, insertion section 34 face 101 bending with the end side of sealing element 13A on the front-end-cone face 122 of the flange part 114 of the front shown in Fig. 7 (a) abuts, afterwards, the locking cylinder face 121 of flange part 114 contacts with the bending face 101 of the end side of sealing element 13A, end side cylinder face 102, convex surface part 103, middle cylinder face 104, convex surface part 105 and another barrel surface portion, side 106 successively, while these contact portions and neighbouring part thereof are stretched vertically to radial outside crimp, be fitted together to.So sealed chamber portion 70A is chimeric with central diameter portion 39 and large-diameter portion 40 as Suo Shi Fig. 7 (b) in the main mode be configured in large-diameter portion 40 by protrusion 131.Now, allow the sealed chamber portion 70A comprising protrusion 131 of sealing element 13A to be out of shape further to radial outside at the large-diameter portion 40 in the front in central diameter portion 39, thus weaken the sliding resistance that flange part 114 is applied.In addition, the sealed chamber portion 70A comprising the protrusion 131 be out of shape laterally because sealing element 13 is extruded by flange part 114 is accommodated in large-diameter portion 40, therefore, it is possible to suppress the overhang to direction of insertion front as the resistance of flange part 114, according to this point, the sliding resistance that flange part 114 is applied also can be weakened.

As shown in Fig. 7 (c), when flange part 114 exceedes sealing element 13A, sealing element 13A and insertion section 34 close contact in an interference fit.When insertion section 34 is suitably inserted into the sealing element 13A being held in connecting portion 28, the end side cylinder face 102 of the sealing element 13A shown in Fig. 6, convex surface part 103, middle cylinder face 104, convex surface part 105 and another barrel surface portion, side 106 abut with the main cylinder face 118 of the insertion section 34 shown in Fig. 4 in an interference fit.Now, as shown in Fig. 7 (c), central diameter portion 39 and the large-diameter portion 40 of sealed chamber portion 70A and connecting portion 28 abut, but, protrusion 131 according to Fig. 6 and the above-mentioned size relationship of connecting portion 28, under using state subsequently, at least its part contacts with central diameter portion 39, and remainder contacts with large-diameter portion 40.Namely, when assembling, base end part 68 is compressed by housing recess 110 and connecting portion 28, even if temporarily there is the state that whole protrusion 131 contacts with large-diameter portion 40, but subsequently, base end part 68 utilize elastic force restore and under making the using state of the position stability of fuel tank main body 31, protrusion 131 be in the state contacted with central diameter portion 39 at least partially.

According to the master cylinder of the second embodiment, leading section due to the sealed chamber portion 70A at sealing element 13A is provided with the diameter protrusion 131 larger than the diameter of sealed chamber portion 70A, therefore when working oil filling, utilize the pressure of working oil, the insertion section 34 of fuel tank main body 31 is moved to extracting direction, when flange part 114 to abut with the path end face 64 of sealing element 13A and by sealing element 13 to extract direction extrude time, the sealed chamber portion 70A with protrusion 131 moves to radially inner side according to the guiding in conical surface portion 53 and is out of shape, and the gap closed between itself and insertion section 34, the contact improved insertion section 34 applies also improves friction force further.Thereby, it is possible to restriction extracts insertion section 34 from connecting portion 28.

In addition, due to protrusion 131 be arranged at least partially contact with the central diameter portion 39 of connecting portion 28 in a state of use, therefore namely sealing element 13A is extruded to the direction contacted with insertion section 34 from central diameter portion 39 to radially inner side all the time.Thus, sealing element 13A can extrude insertion section 34 in a state of use, and can limit and extracted from connecting portion 28 insertion section 34 in a state of use.

" the 3rd embodiment "

Then, mainly the master cylinder of the 3rd embodiment is described centered by the part different from the first embodiment based on Fig. 8 with Fig. 9.And the position identical with the first embodiment uses same title, prosign represents.

In the third embodiment, the connecting portion 28B with large-diameter portion 40B and minor diameter part 41B different relative to connecting portion 28 local of the first embodiment is used.The large-diameter portion 40B of the connecting portion 28B of the 3rd embodiment and minor diameter part 41B substitutes the conical surface portion 55 of the first embodiment, and has bending face 141.

Bending face 141 is formed as more extending to side, cylinder portion 16 to the less arc-shaped of cylinder portion 16 side diameter from the end edge portion of the side, cylinder portion 16 of bending facial 54, and the shape comprising the cross section of the central axis of connecting bore 29 is arc-shaped.The radius of curvature of bending face 141 is larger than the radius of curvature of bending face 54, and is formed as more away from bending facial 54 larger shapes.The part that bending face 141 is connected with base end side cylinder face 58 is along the direction orthogonal to the axial direction of connecting bore 29.In other words, bending face 141 is connected orthogonally with base end side cylinder face 58.

Then, the connection structure between connecting portion 28B, sealing element 13, insertion section 34 is described according to its engagement step.

First, identically with the first embodiment that sealing element 13 is chimeric with connecting portion 28B.Now, as shown in Fig. 9 (a), sealing element 13 makes its sealed chamber portion 70 abut with central diameter portion 39 and large-diameter portion 40B.

Then, as shown in Fig. 9 (a) to 9 (b), the insertion section 34 of fuel tank main body 31 is inserted into the sealing element 13 being held in connecting portion 28B identically with the first embodiment.Now, more than even if the flange part 114 of insertion section 34 stretches, sealing element 13 is envisioned, owing to bending bending facial 141 abutting with sealing element 13 orthogonally with base end side cylinder face 58, enter between the base end side cylinder face 58 of flange part 114 and minor diameter part 41B therefore, it is possible to limit sealing element 13.

According to the master cylinder of the 3rd above embodiment, because bending facial 141 of the large-diameter portion 40B side of minor diameter part 41B are connected with base end side cylinder face 58 in the mode orthogonal with base end side cylinder face 58, so when assembling, even if such as sealing element 13 is stretched more than anticipation by flange part 114, also can limit this part further to enter between flange part 114 and minor diameter part 41B, and the damage of sealing element 13 can be suppressed further.

According to above-mentioned embodiment, the oil cylinder of pressure is produced being slided by piston, to the fuel tank of described oil cylinder supply working fluid, to be arranged on described oil cylinder and to connect the tubular connecting portion of described fuel tank, be arranged on described fuel tank and the tubular insertion section of inserting in described connecting portion, to be arranged between above-mentioned connecting portion and above-mentioned insertion section and to there is elasticity and seal in master cylinder that the cartridge seal parts between these connecting portion and insertion sections form, described insertion section has in front to the flange part that radial outside is expanded, described connecting portion has: the front of the side face that sets within it and the first inside diameter of the diameter ring-type larger than the external diameter of above-mentioned flange part, be arranged on the base end side of this first inside diameter and diameter second inside diameter larger than this first inside diameter, be positioned at the base end side of this second inside diameter and diameter three inside diameter larger than this second inside diameter, described sealing element has: the base end part that the diameter abutted with the front end face of described connecting portion is large, the fitting portion of the ring-type chimeric with the first inside diameter of described connecting portion, the sealed chamber portion abutted with on position that is described base end part opposite side vertically and with the second inside diameter of described insertion section and described connecting portion that is that be arranged on this fitting portion.Thereby, it is possible to the sliding resistance that reduction sealing element applies insertion section.Therefore, though increase flange part radial elongation thus restriction insertion section come off from connecting portion, also can obtain good assembleability.In addition, due to connecting portion large-diameter portion more by base end side can there is the mode relative with flange part the diameter minor diameter part less than the diameter of fitting projection, even if therefore such as sealing element is by more than flange part stretching anticipation, also can limit this part enters between flange part and minor diameter part, can suppress the damage of sealing element.

In addition, because described sealing element is on its outer peripheral face, the leading section in described sealed chamber portion is provided with the diameter protrusion larger than the diameter in sealing cylinder portion, therefore, it is possible to restriction insertion section comes off from connecting portion.

In addition, because described 3rd inside diameter of described connecting portion has the reducing diameter part reducing diameter to described second inside diameter gradually, therefore when insertion section is moved to extracting direction relative to connecting portion, and flange part by sealing element to extract direction extruding time, sealing element moves to radially inner side according to the guiding of reducing diameter part and is out of shape, improve the contact that insertion section is applied, improve friction force.Thereby, it is possible to restriction extracts insertion section from connecting portion.

In addition, due to contacting with described second inside diameter in a state of use at least partially of described protrusion, therefore sealing element can extrude insertion section in a state of use, can limit and extract insertion section from connecting portion in a state of use.In addition, in the respective embodiments described above, illustrate and be connected with the connecting portion 28 of master cylinder the example preventing from coming off with the insertion section 34 of fuel tank by means of only by sealing element 13, but the present invention also goes for the master cylinder that the use pin etc. shown in patent documentation 1 is connected with fuel tank master cylinder.Thus, inserting pin etc. even if to suppose when safeguarding etc. to forget, also can prevent from extracting fuel tank from master cylinder.

Claims (5)

1. a master cylinder, it has:

Piston slides and produces the oil cylinder of pressure;

To the fuel tank of described oil cylinder supply working fluid;

To be arranged on described oil cylinder and to connect the tubular connecting portion of described fuel tank;

To be arranged on described fuel tank and to insert the tubular insertion section of described connecting portion;

Being arranged between described connecting portion and described insertion section and having elasticity and seal the sealing element of the tubular between described connecting portion and insertion section, the feature of this master cylinder is,

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

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

Described sealing element has: abut with the front end face of described connecting portion and the diameter base end part larger than the diameter of the end of the front end face side of described connecting portion; The fitting portion of the ring-type chimeric with the first inside diameter of described connecting portion; The sealed chamber portion abutted with on position that is described base end part opposite side vertically and with the second inside diameter of described insertion section and described connecting portion that is that be arranged on this fitting portion.

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

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

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

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

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

Being set at least partially of described protrusion contacts with described second inside diameter in a state of use.

5. the master cylinder according to any one in Claims 1-4, is characterized in that,

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