Variable compression ratio control system for internal combustion engine
First Claim
1. A variable compression ratio control system for an internal combustion engine, comprising:
- a lubrication system for selectively providing oil to connecting rods within the engine at either a lubrication pressure or at a control pressure;
a plurality of compression ratio adjusters responsive to the pressure of lubricating oil being provided to the connecting rods through said lubrication system, with one of said compression ratio adjusters being associated with each of said connecting rods; and
a lubricating pump for providing lubricating oil to said connecting rods through said lubrication system, with said lubricating pump being selectively operable at one of said lubricating pressure and said control pressure.
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Accused Products
Abstract
A variable compression ratio control system for an internal combustion engine includes a lubrication system for selectively providing lubricating oil to connecting rods within the engine at either a lubrication pressure or at a control pressure. The oil is provided to compression ratio adjusters so as to cause the adjusters to move from one compression ratio to another, to achieve a desired change in compression ratio. A lubricating pump provides lubricating oil to the connecting rods through the lubrication system. The lubricating pump is selectively operable at one of a lubricating pressure and a control pressure by means of a control valve which is integral with the lubricating pump.
27 Citations
17 Claims
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1. A variable compression ratio control system for an internal combustion engine, comprising:
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a lubrication system for selectively providing oil to connecting rods within the engine at either a lubrication pressure or at a control pressure;
a plurality of compression ratio adjusters responsive to the pressure of lubricating oil being provided to the connecting rods through said lubrication system, with one of said compression ratio adjusters being associated with each of said connecting rods; and
a lubricating pump for providing lubricating oil to said connecting rods through said lubrication system, with said lubricating pump being selectively operable at one of said lubricating pressure and said control pressure. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A variable compression ratio control system for an internal combustion engine having a crankshaft with a plurality of main bearings, and with a plurality of connecting rods being attached to said crankshaft, with said variable compression ratio control system comprising:
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a lubrication system for providing lubricating oil to a plurality of components within the engine, with said lubrication system having a main bearing oil supply passage which is bifurcated into two passages such that a first group of main bearings is provided with oil by one of said passages, and a second group of main bearings is provided with oil by the other of said passages;
a plurality of compression ratio adjusters responsive to the relative pressures of the lubricating oil being provided to the first and second groups of main bearings through said bifurcated oil passages, with one of said compression ratio adjusters being associated with each of said connecting rods, and with said compression ratio adjusters being switchable between a higher compression ratio and a lower compression ratio; and
a dual purpose lubricating pump for providing lubricating oil to said connecting rods through said bifurcated oil passages, with said lubricating pump having an integral pressure regulator which discharges oil from the pump at a lower pressure during normal operation of the engine, and at a higher pressure when the compression ratio adjusters are being switched from one compression ratio to the other compression ratio. - View Dependent Claims (12, 13, 14, 15, 16)
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17. A method for operating a variable compression ratio control system for a reciprocating internal combustion engine, comprising the steps of:
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determining a compression ratio at which the engine is to be operated;
increasing the discharge pressure of an engine lubricating pump from a lower pressure used during normal operation to a high pressure sufficient to operate a plurality of compression ratio adjusters; and
applying lubricating oil at said higher pressure to said compression ratio adjusters to cause the compression ratio to be adjusted.
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Specification