EP0317364A1
Expired / Lapsed
EP
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Valve operating system for internal combustion engine
Assignee: Honda Motor Co Ltd
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Filing: 1988-11-21
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Granted: —
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Expires: 2008-11-21
Abstract
Abstract A valve-operating system for an internal combustion engine, which system includes a valve-driving piston (13) slidably received in a cylinder body(12) and operatively connected at one end of the piston to an engine valve(5) spring-biased in a closing direction. A check valve (41) and an orifice (45)are interposed between a hydraulic pressure generating means for generating an oil pressure for causing opening of the engine valveand a damper chamber (39) defined between the cylinder body and the valve-driving piston. The check valve permits only the flow of working oil from the hydraulic pressure generating means to the damper chamber. The orifice restricts the return of working oil from the damper chamber to the hydraulic pressure generating means. The orifice is made sufficiently short relative to its width to reduce the influence due to viscosity variations of the working oil to an extremely small level.
Inventors
- 👤 Yoshihiro C/O Kabushiki Kaisha Fujiyoshi
- 👤 Koichi C/O Kabushiki Kaisha Fukuo
- 👤 Hidenobu C/O Kabushiki Kaisha Nagase
- 👤 Takatoshi C/O Kabushiki Kaisha Aoki
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 07:27
CPC Classifications
F; F01; F01L; F01L1/00; F01L1/12; F01L1/14; F01L1/16; F01L9/00; F01L9/10; F01L9/11; F01L9/12
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
143 words
A valve-operating system for an internal combustion engine, comprising a valve-driving piston slidably received in a cylinder body and operatively connected at one end thereof to an engine valve which is spring-biased in a closing direction, and a check valve and an orifice interposed between hydraulic pressure generating means for generating an oil pressure for causing opening of the engine valve and a damper chamber defined between the cylinder body and the valve-driving piston, said check valve permitting flow of a working oil only from said hydraulic pressure generating means to the damper chamber, and said orifice restricting returning of the working oil from the damper chamber to the hydraulic pressure generating means, wherein said orifice is made sufficiently small to substantially reduce an influence on the flow of the working oil through the orifice caused by viscosity variations of the working oil.
Claim 2
Dependent Claim
143 words
A valve-operating system for an internal combustion engine, comprising a valve-driving piston slidably received in a cylinder body and operatively connected at one end thereof to an engine valve which is spring-biased in a closing direction, and a check valve and an orifice interposed between hydraulic pressure generating means for generating an oil pressure for causing opening of the engine valve and a damper chamber defined between the cylinder body and the valve-driving piston, said check valve permitting flow of a working oil only from said hydraulic pressure generating means to the damper chamber, and said orifice restricting returning of the working oil from the damper chamber to the hydraulic pressure generating means, wherein said orifice is made sufficiently small to substantially reduce an influence on the flow of the working oil through the orifice caused by viscosity variations of the working oil.
Claim 3
Dependent Claim
25 words
A valve-operating system for an internal combustion engine according to claim 1, wherein said orifice is provided in a valve member of the check valve.
Claim 4
Dependent Claim
21 words
A valve-operating system for an internal combustion engine according to claim 1, wherein said orifice is provided in the valve-driving piston.
Claim 5
Dependent Claim
21 words
A valve-operating system for an internal combustion engine according to claim 1, wherein said orifice is provided in the cylinder body.
Claim 6
Dependent Claim
48 words
A valve-operating system for an internal combustion engine according to claim 3 or 4, wherein said orifice is formed as a variable orifice whose opening area is reduced in response to movement of the valve-driving piston within the cylinder body in the direction to close the engine valve.
Claim 7
Dependent Claim
202 words
A valve-operating system for an internal combustion engine, comprising a valve-driving piston slidably received in a cylinder body and operatively connected at one end thereof to an engine valve which is spring-biased in a closing direction, and a check valve and an orifice.means interposed between hydraulic pressure generating means for generating an oil pressure for causing opening of the engine valve and a damper chamber defined between the cylinder body and the valve-driving piston, said check valve permitting flow of a working oil only from said hydraulic pressure generating means to the damper chamber, wherein said orifice means comprises a variable orifice whose opening area is reduced in response to movement of the valve-driving piston within the cylinder body in the direction to close the engine valve and an invariable orifice whose opening area is constant despite the movement of the valve-driving piston within the cylinder body, said orifice means restricting returning of the working oil from the damper chamber to the hydraulic pressure generating means, wherein said orifice means is made small enough to reduce to an extremely small level an influence on the flow of the working oil through the orifice means caused by viscosity variations of the working oil.
Claim 8
Dependent Claim
202 words
A valve-operating system for an internal combustion engine, comprising a valve-driving piston slidably received in a cylinder body and operatively connected at one end thereof to an engine valve which is spring-biased in a closing direction, and a check valve and an orifice.means interposed between hydraulic pressure generating means for generating an oil pressure for causing opening of the engine valve and a damper chamber defined between the cylinder body and the valve-driving piston, said check valve permitting flow of a working oil only from said hydraulic pressure generating means to the damper chamber, wherein said orifice means comprises a variable orifice whose opening area is reduced in response to movement of the valve-driving piston within the cylinder body in the direction to close the engine valve and an invariable orifice whose opening area is constant despite the movement of the valve-driving piston within the cylinder body, said orifice means restricting returning of the working oil from the damper chamber to the hydraulic pressure generating means, wherein said orifice means is made small enough to reduce to an extremely small level an influence on the flow of the working oil through the orifice means caused by viscosity variations of the working oil.
Claim 9
Dependent Claim
49 words
A valve-operating system for an internal combustion engine according to claim 6, wherein said variable orifice is formed such that its opening area becomes zero at that moved position of the valve-driving piston within the cylinder body which corresponds to a location just before seating of the engine valve.
Claim 10
Dependent Claim
55 words
A valve-operating system for an internal combustion engine according to claims 1, 2, 3 or 4 wherein the orifice has a size represented by L/D² being equal to or less than 3, wherein L is the axial length of the orifice in the direction of oil flow and D is the width of the orifice.
Claim 11
Dependent Claim
24 words
A valve operating system for an internal combustion engine according to claim 8, wherein the orifice is circular and D is the diameter thereof.
Claim 12
Dependent Claim
58 words
A valve operating system for an internal combustion engine according to claim 6 or 7, wherein the invariable orifice is circular and has a size represented by L/D² being equal to or less than 3, wherein L is the axial length of the orifice in the direction of oil flow and D is the diameter of the orifice.
Claim 13
Dependent Claim
145 words
A valve-operating system for an internal combustion engine, comprising, a valve-driving piston slidably received in a cylinder and operatively connected at one end thereof to an engine valve, hydraulic pressure generating means for generating an oil pressure in the cylinder to force the valve-driving piston in a direction for opening of the engine valve, a damper chamber defined between the cylinder and the valve-driving pistcn at least in a final valve-closing movement of the valve-driving piston, and an orifice means communicating with said damper chamber for restricting the flow of the working oil from the damper chamber for controlling the valve closing, said orifice means having a small length in the direction of oil flow as compared to the cross-sectional flow area for minimizing any effect of variations in viscosity of the oil whereby the valve closing is substantially consistent under any oil viscosity variations.
Claim 14
Dependent Claim
145 words
A valve-operating system for an internal combustion engine, comprising, a valve-driving piston slidably received in a cylinder and operatively connected at one end thereof to an engine valve, hydraulic pressure generating means for generating an oil pressure in the cylinder to force the valve-driving piston in a direction for opening of the engine valve, a damper chamber defined between the cylinder and the valve-driving pistcn at least in a final valve-closing movement of the valve-driving piston, and an orifice means communicating with said damper chamber for restricting the flow of the working oil from the damper chamber for controlling the valve closing, said orifice means having a small length in the direction of oil flow as compared to the cross-sectional flow area for minimizing any effect of variations in viscosity of the oil whereby the valve closing is substantially consistent under any oil viscosity variations.
Claim 15
Dependent Claim
34 words
A valve-operating system according to claim 11, wherein said orifice means is a round hole of a diameter D and said length is L, and wherein L/D² is equal to or less than 3.
Claim 16
Dependent Claim
40 words
A valve-operating system according to claim 11, wherein said orifice is a notch in a thin wall of the valve-driving piston that cooperates with the cylinder to progressively cover said notch as the valve proceeds through the final closing movement.
Claim 17
Dependent Claim
24 words
A valve-operating system according to claim 13, wherein said notch is V-shaped to provide a progressively reducing orifice means size as the valve closes.
Claim 18
Dependent Claim
40 words
A valve-operating system according to claim 13, wherein said notch is rectangular in shape with a width W perpendicular to the direction of movement of the valve-driving piston and said length is L, and wherein L/W² is one or less.
References Cited (Backward Citations)
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