2-cycle engine with valve system and method for controlling the engine
AssigneesHyundai Motor Company, Kia Motors Corporation
InventorsMyung Sik Choi, In Gee Suh, Woo Tae Kim
Life of this patent
Estimating the term…
Abstract
The present disclosure relates to a 2-cycle engine with a valve system that generates power during every one crankshaft rotation. The 2-cycle engine of the present disclosure includes the valve system opening and closing an air intake valve and an exhaust valve and includes a turbocharger. In the turbocharger, the air intake valve and the exhaust valve are respectively opened and closed once during one crankshaft rotation, and the valve system is configured to control the turbocharger using difference between an air intake pressure and an exhaust pressure. Accordingly, a current air intake reaches a target air intake.
Claims9
A 2-cycle engine with a valve system, the 2-cycle engine comprising:
- a camshaft rotated in conjunction with a crankshaft;
- a valve system configured such that an air intake valve and an exhaust valve are opened or closed depending on the camshaft rotation;
- a turbocharger compressing air and supplying the compressed air into a cylinder;
- and
- a controller controlling operation of the turbocharger using a difference between an intake pressure and an exhaust pressure so that a current air intake reaches a target air intake,
- wherein the air intake valve and the exhaust valve are opened and closed once, respectively, during one crankshaft rotation,
- wherein the controller comprises:
- a calculation unit that calculates engine demand torque based on factors reflecting vehicle traveling conditions, calculates the target air intake desired for generating the engine demand torque when current engine torque is less than the engine demand torque, and calculates a target air intake/exhaust pressure difference value corresponding to the target air intake;
- an input unit receiving a current intake pressure of an air intake manifold at an air intake valve closing time and a current exhaust pressure of an exhaust manifold at an exhaust valve closing time;
- a comparison determination unit comparing a current air intake/exhaust pressure difference value that is a difference value between the current intake pressure of the air intake manifold at the air intake valve closing time and the current exhaust pressure of the exhaust manifold at the exhaust valve closing time with the target air intake/exhaust pressure difference value;
- and
- an output unit configured to increase a rotation speed of the turbocharger when the target air intake/exhaust pressure difference value is higher than the current air intake/exhaust pressure difference value, and configured to decrease the rotation speed of the turbocharger when the target air intake/exhaust pressure difference value is equal to or less than the current air intake/exhaust pressure difference value.
A method for controlling a 2-cycle engine comprising a camshaft rotated in conjunction with a crankshaft, a valve system configured such that an air intake valve and an exhaust valve are opened or closed depending on the camshaft rotation, a turbocharger compressing air and supplying the compressed air into a cylinder, and a controller controlling operation of the turbocharger, wherein the air intake valve and the exhaust valve are opened and closed once, respectively, during one crankshaft rotation, the method comprising:
- controlling operation of the turbocharger using a difference between an intake pressure and an exhaust pressure so that a current air intake reaches a target air intake;
- calculating engine demand torque based on factors reflecting a vehicle traveling state;
- calculating target air intake desired for generating the engine demand torque when current engine torque is less than the engine demand torque;
- calculating a target air intake/exhaust pressure difference value corresponding to the target air intake;
- receiving a current intake pressure of an air intake manifold at an air intake valve closing time and a current exhaust pressure of an exhaust manifold at an exhaust valve closing time;
- calculating a current air intake/exhaust pressure difference value by comparing the current intake pressure of the air intake manifold at the air intake valve closing time and the current exhaust pressure of the exhaust manifold at the exhaust valve closing time;
- and
- controlling a rotation speed of the turbocharger to increase the rotation speed when the target air intake/exhaust pressure difference value is higher than the current air intake/exhaust pressure difference value, and controlling the rotation speed of the turbocharger to decrease the rotation speed when the target air intake/exhaust pressure difference value is equal to or less than the current air intake/exhaust pressure difference value.
Dependencies are inferred from the claim text.