# US 2013/0152888 A1 · Engine that actively varies compression expansion ratio

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 2013/0152888 A1
- Document ID: US20130152888A1
- Status: Published application
- Kind: A1
- Application number: 13/488,975
- Filed: 2012-06-05
- Published: 2013-06-20
- Earliest claimed: 2011-12-14
- Assignees: Hyundai Motor Company
- Inventors: Jin Hee Cho
- Web page: https://patentgrep.com/patent/US20130152888A1

## CPC

- F02D 13/0269: {Controlling the valves to perform a Miller-Atkinson cycle}
- F01L 1/047: Camshafts
- F01L 1/34: characterised by the provision of means for changing the timing of the valves without changing the duration of opening {and without affecting the magnitude of the valve lift}
- F01L 1/34413: {using composite camshafts, e.g. with cams being able to move relative to the camshaft}
- F02D 13/0203: {Variable control of intake and exhaust valves}
- F01L 2001/0473: {Composite camshafts, e.g. with cams or cam sleeve being able to move relative to the inner camshaft or a cam adjusting rod}
- Y02T 10/12: Improving ICE efficiencies
- F02D: CONTROLLING COMBUSTION ENGINES (vehicle fittings, acting on a single sub-unit only, for automatically controlling vehicle speed B60K31/00; conjoint control of vehicle sub-units of different type or different function, road vehicle drive control systems for purposes other than the control of a single sub-unit B60W)
- F01L: CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES
- Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION

## Abstract

An engine that actively varies a compress expansion ratio may include an intake camshaft to which an intake cam may be formed to lift an intake valve, an exhaust camshaft to which an exhaust cam may be formed to lift an exhaust valve, an intake valve variable timing unit disposed at one end portion of the intake camshaft to advance or retard a rotation of the intake camshaft, an exhaust valve variable timing unit disposed at one end portion of the exhaust camshaft to advance or retard a rotation of the exhaust camshaft, an intake valve variable duration unit disposed at the other end portion of the intake camshaft to vary a lift duration of the intake camshaft, and an exhaust valve variable duration unit disposed at the other end portion of the exhaust camshaft to vary a lift duration of the exhaust camshaft.

## Claims

### Claim 1

An engine that actively varies a compress expansion ratio, comprising:
an intake camshaft to which an intake cam is formed to lift an intake valve;
an exhaust camshaft to which an exhaust cam is formed to lift an exhaust valve;
an intake valve variable timing unit that is disposed at one end portion of the intake camshaft to advance or retard a rotation of the intake camshaft;
an exhaust valve variable timing unit that is disposed at one end portion of the exhaust camshaft to advance or retard a rotation of the exhaust camshaft;
an intake valve variable duration unit that is disposed at the other end portion of the intake camshaft to vary a lift duration of the intake camshaft; and
an exhaust valve variable duration unit that is disposed at the other end portion of the exhaust camshaft to vary a lift duration of the exhaust camshaft.

### Claim 2 (depends on 1)

The engine of claim 1, wherein an air flow sensor is mounted to an intake line to detect air flow amount that is supplied from the intake line to a combustion chamber of a cylinder through the intake valve.

### Claim 3 (depends on 1)

The engine of claim 1, wherein the intake camshaft includes:
an intake outer pipe to which the intake valve variable timing unit is engaged, wherein a rotation position of the intake outer pipe is advanced or retarded by the intake valve variable timing unit and wherein an intake outer cam is formed on an exterior circumference of the intake outer pipe; and
an intake inner pipe to which the intake valve variable duration unit is engaged, wherein a rotation position of the intake inner pipe is advanced or retarded by the intake valve variable duration unit and wherein an intake inner cam is formed on an exterior circumference of the intake inner pipe,
wherein the intake inner pipe is slidably inserted into the intake outer pipe.

### Claim 4 (depends on 3)

The engine of claim 3, further comprising;
an outer cam fixation pin that fixes the intake outer cam on the exterior circumference of the intake outer pipe, wherein a slot is formed in the intake outer pipe along a circumferential direction thereof, and
an inner cam fixation pin that fixes the intake inner cam slidably mounted on the intake outer cam, to the intake inner pipe through the slot.

### Claim 5 (depends on 3)

The engine of claim 3, wherein the intake valve includes a first intake valve and a second intake valve that supplies a combustion chamber with air, wherein the first intake valve is lifted by the intake outer cam and a lift timing thereof is continuously varied and the second intake valve is lifted by the intake inner cam and a lift duration thereof is continuously varied.

### Claim 6 (depends on 5)

The engine of claim 5, wherein a first exterior diameter of a first mounting portion to which the intake valve variable timing unit is mounted at one end portion of the intake outer pipe and a second exterior diameter of a second mounting portion to which the intake valve variable duration unit is mounted at one end portion of the intake inner pipe have an equal diameter length.

### Claim 7 (depends on 6)

The engine of claim 6, wherein the shape of the first mounting portion that the intake valve variable timing unit is mounted at the one end portion of the intake outer pipe and the shape of the second mounting portion that the intake valve variable duration unit is mounted at the one end portion of the intake inner pipe are formed symmetrically from each other.