Method for providing variable compression ratio in an internal combustion engine and actuator for said method
First Claim
1. A method to control the size of a combustion chamber by an actuator in the cylinder head of a piston combustion engine comprising:
- A combustion chamberA vertically displaceable piston arranged in the combustion chamber; and
An actuator comprising;
A first chamber with a first shaft extending through the first chamber and connected to the piston, the first shaft having a flange and a spring disposed in the first chamber, the spring acting between the flange and a chamber floor to force the piston in an upward direction;
A second chamber and a third chamber filled with hydraulic fluid and separated by a valve with an opening, wherein the valve is horizontally repositionable via an electromagnet;
A step motor and a second shaft vertically displaceable by said step motor in the second chamber,Wherein an upper part of the first shaft extends into the third chamber such that the hydraulic fluid may act thereon,the method comprising changing the size of the combustion chamber by;
displacing the valve with the electromagnet so that the opening connects the second and third chambers, anddisplacing the second shaft using the step motor to cause a flow of hydraulic fluid between the second chamber and the third chamber, thereby repositioning the first shaft and the thereto-connected piston.
1 Assignment
0 Petitions
Accused Products
Abstract
In a combustion chamber of a piston combustion engine there is a displaceable piston that can be moved progressively up or down between an upper and a lower turning position. The displacement takes place via an electrically controlled step motor which is connected to the piston via a hydraulic link, including a hydraulic lock. The lock is deactivated during the displacement a certain number of steps up or down ordered by a motor control system, and when the displacement is ended, the lock is activated by said engine control system and the moving piston is locked in a certain position ordered by the motor control system.
7 Citations
8 Claims
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1. A method to control the size of a combustion chamber by an actuator in the cylinder head of a piston combustion engine comprising:
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A combustion chamber A vertically displaceable piston arranged in the combustion chamber; and An actuator comprising; A first chamber with a first shaft extending through the first chamber and connected to the piston, the first shaft having a flange and a spring disposed in the first chamber, the spring acting between the flange and a chamber floor to force the piston in an upward direction; A second chamber and a third chamber filled with hydraulic fluid and separated by a valve with an opening, wherein the valve is horizontally repositionable via an electromagnet; A step motor and a second shaft vertically displaceable by said step motor in the second chamber, Wherein an upper part of the first shaft extends into the third chamber such that the hydraulic fluid may act thereon, the method comprising changing the size of the combustion chamber by; displacing the valve with the electromagnet so that the opening connects the second and third chambers, and displacing the second shaft using the step motor to cause a flow of hydraulic fluid between the second chamber and the third chamber, thereby repositioning the first shaft and the thereto-connected piston. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A cylinder head for a diesel engine comprising:
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a combustion chamber arranged in the cylinder head; a vertically displaceable piston arranged in said combustion chamber; and an actuator comprising; a first chamber; a first shaft connected to the piston, the first shaft extending through the first chamber and provided with a flange disposed in the chamber; a spring arranged between the flange and a floor of the first chamber; a second chamber and a third chamber filled with hydraulic fluid; a valve provided with an opening between the second and third chambers; an electromagnet arranged to actuate the valve; a second shaft displaceably arranged in the second chamber; and a step motor arranged to displace the second shaft, wherein an upper part of the first shaft extends into the third chamber such that the hydraulic fluid may act thereon to allow for changing a size of the combustion chamber by displacing the valve so that the opening connects the two hydraulic fluid chambers and by displacing the second shaft using the step motor to cause a flow of hydraulic fluid between the second chamber and the third chamber, thereby repositioning the first shaft and the thereto connected piston.
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Specification