Valve train in internal combustion engine
AssigneeToyota Jidosha Kabushiki Kaisha
InventorsNaoki Kurata, Masanori Sugiyama, Daichi Yamazaki
Life of this patent
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Abstract
A valve train for driving an engine valve in an internal combustion engine. A pump having a pressure chamber compresses and supplies fuel to the engine. An intake camshaft has valve cams for selectively opening and closing the intake valves and a pump cam for driving the pump. The intake camshaft has a torque fluctuation as a result of driving the intake valves and as a result of compressing fuel by the pump. A timing belt connects a crankshaft to the intake camshaft. The pump cam has a phase with respect to the intake camshaft to reduce a composite of the torque fluctuation (the net torque fluctuation) generated in the intake camshaft by the intake valves and the pump. This improves the life of the timing belt.
Claims15
A valve train for driving an engine valve in an internal combustion engine, the valve train comprising:
- a camshaft;
- a crankshaft;
- a pump for supplying fuel in a reservoir to the engine, wherein the pump has a pressure chamber for compressing fuel;
- a valve cam provided on the camshaft for selectively opening and closing the engine valve, wherein the camshaft has a first torque fluctuation cycle that corresponds to the rotation of the crankshaft as a result of driving the engine valve;
- a pump cam provided on the camshaft for driving the pump, wherein the camshaft has a second torque fluctuation cycle that corresponds to the rotation of the crankshaft as a result of compressing fuel by the pump;
- and
- a transmission mechanism for transmitting the torque of the crankshaft to the camshaft,
- wherein the pump cam has a phase with respect to the camshaft to reduce a composite of the first and second torque fluctuation cycles.
A valve train for driving an engine valve in an internal combustion engine, the valve train comprising:
- a camshaft;
- a crankshaft;
- a pump for supplying fuel in a reservoir to the engine, wherein the pump has pressure chamber for compressing fuel;
- a valve cam provided on the camshaft for selectively opening and closing the engine valve, wherein the camshaft has a first torque fluctuation cycle that corresponds to the rotation of the crankshaft as a result of driving the engine valve;
- a pump cam provided on the camshaft for driving the pump, wherein the camshaft has a second torque fluctuation cycle that corresponds to the rotation of the crankshaft as a result of compressing fuel by the pump;
- a transmission mechanism for transmitting the torque of the crankshaft to the camshaft;
- a spill passage connected to the pressure chamber for returning fuel to the reservoir;
- a control valve positioned in the spill passage, wherein the pump compresses fuel only when the control valve is closed;
- and
- a controller for selectively opening and closing the control valve to reduce the composite of the first and second torque fluctuation cycles.
Dependencies are inferred from the claim text.