Hydraulic master cylinder for vehicle
A hydraulic master cylinder for vehicle has: a cylinder main body; a sleeve; a plurality of seal rings; a plug, a lid member comprising the sleeve and the plug; and a piston inserted into the cylinder bore so as to form a hydraulic pressure chamber between the piston and the lid member; wherein the sleeve is inserted into the cylinder main body with an open end thereof being made to face an interior of the cylinder main body so as to dispose the seal rings between a circumferential wall of the cylinder bore and the sleeve and in such a manner that the seal rings hold the outlet port therebetween, and the plug is fixedly threaded in the opening at the one end so as to prevent the dislocation of the sleeve.
1. A hydraulic master cylinder for vehicle comprising:
a cylinder main body opening at both ends thereof and including a discharge port;
a bottomed cylindrical sleeve inserted into the cylinder main body and including an outlet port for a working fluid communicating with the discharge port;
a plurality of seal rings for sealing a periphery of the outlet port fluid tightly;
a plug having a threaded portion on an outer circumference thereof and abutting with the sleeve, a lid member comprising the sleeve and the plug, and mounted via the seal rings in an opening at one end of the cylinder main body so as to form a bottomed cylinder bore; and
a piston inserted into the cylinder bore so as to form a hydraulic pressure chamber between the piston and the lid member;
wherein the sleeve is inserted into the cylinder main body with an open end thereof being made to face an interior of the cylinder main body so as to dispose the seal rings between a circumferential wall of the cylinder bore and the sleeve and in such a manner that the seal rings hold the outlet port therebetween, and the plug is fixedly threaded in the opening at the one end so as to prevent the dislocation of the sleeve.
2. A hydraulic master cylinder for vehicle as set forth in claim 1 , wherein the plurality of seal rings are O rings having the same diameter.
3. A hydraulic master cylinder for vehicle as set forth in claim 2 , wherein a cover member for covering the plug is mounted on one end portion of the cylinder main body.
4. A hydraulic master cylinder for vehicle as set forth in claim 3 , wherein the cover member is formed integrally with a reservoir mounted on the cylinder main body for storing a working fluid.
5. A hydraulic master cylinder for vehicle as set forth in claim 1 , wherein a cover member for covering the plug is mounted on one end portion of the cylinder main body.
6. A hydraulic master cylinder for vehicle as set forth in claim 5 , wherein the cover member is formed integrally with a reservoir mounted on the cylinder main body for storing a working fluid.
7. A hydraulic master cylinder for vehicle as set forth in claim 1 , wherein a hexagonal hole is opened in a central portion of the plug for insertion of a tool.
8. A hydraulic master cylinder for vehicle as set forth in claim 1 , further comprising:
an annular cup seal disposed within the cylinder bore and having an outer circumferential lip portion resiliently contacting an inner wall of the cylinder bore, an inner circumferential lip portion resiliently contacting an outer wall of a piston and a base portion coupling both the lip portions together at base portions thereof;
the plurality of raised portions disposed circumferentially on the base portion;
a piston guide entering a recessed portion between the lip portions of the cup seal;
wherein the cup seal is held within the cylinder bore with a plurality of raised portions being in abutment with an end face of the piston guide.
9. A hydraulic master cylinder for vehicle as set forth in claim 8 , the plurality of raised portions are disposed at positions closer to the inner circumferential lip portion than a middle between the lip portions.
10. A hydraulic master cylinder for vehicle as set forth in claim 8 , wherein the cup seal is such that a back side of the base portion is made to incline towards a distal end of the outer circumferential lip portion.
11. A hydraulic master cylinder for vehicle comprising:
a cylinder main body having a first portion and a second portion having a thread, the second portion being larger than the first portion, the cylinder main body opening at both ends thereof and including a discharge port;
a lid member, comprising two components including:
a sleeve positioned in the first portion of the cylinder main body and including an outlet port for a working fluid communicating with the discharge port;
a plug having a threaded portion which threadably engages with the thread of the second portion of the cylinder main body, the plug being in abutment with the sleeve;
a plurality of seals disposed about the sleeve for sealing a periphery of the outlet port of the sleeve; and
a piston inserted into a cylinder bore of the cylinder main body so as to form a hydraulic pressure chamber between the piston and the lid member.
12. A hydraulic master cylinder for vehicle as set forth in claim 11 , wherein the sleeve is inserted into the cylinder main body with an open end thereof being made to face an interior of the main body so as to dispose the seals between a wall of the cylinder bore and the sleeve and in such a manner that the seals hold the outlet port therebetween, and the plug is fixedly threaded in the opening at the one end so as to prevent the dislocation of the sleeve.
13. A hydraulic master cylinder for vehicle as set forth in claim 11 , wherein a cover member is formed integrally with a reservoir mounted on the cylinder main body, the cover covering the plug on one end portion of the cylinder main body.
14. A hydraulic master cylinder for vehicle as set forth in claim 11 , wherein the cylinder main body includes:
a distal end small diameter portion which is formed at a front thereof;
a small diameter bore which is slightly larger in diameter than the distal end small diameter portion;
the first portion which is an intermediate diameter bore; and
the second portion which is a largest diameter bore which is formed at a rear of the cylinder main body.
15. A hydraulic master cylinder for vehicle as set forth in claim 11 , wherein the sleeve is formed into a bottomed cylindrical shape having a circumferential wall and a bottom wall, circumferential grooves are formed at opposing sides of the outlet port.
16. A hydraulic master cylinder for vehicle as set forth in claim 15 , wherein the seals are disposed about the circumferential grooves and are of a same diameter.
17. A hydraulic master cylinder for vehicle as set forth in claim 11 , wherein the seals are disposed in grooves of the sleeve, and the outlet port is positioned between the seals.
18. A hydraulic master cylinder for vehicle comprising:
a cylinder main body having an opening at both ends thereof and including a discharge port;
a sleeve positioned within the cylinder main body;
a plug positioned within the cylinder main body and in abutment with the sleeve;
a plurality of seals disposed about the sleeve for sealing a periphery of an outlet port of the sleeve;
a piston inserted into a cylinder bore of the cylinder main body so as to form a hydraulic pressure chamber between the piston and the sleeve; and
a cover member mounted on one end portion of the cylinder main body for covering the plug, the cover member being formed integrally with a reservoir mounted on the cylinder main body for storing a working fluid.
19. A hydraulic master cylinder for vehicle as set forth in claim 18 , wherein the sleeve and the plug comprises a lid member.