A kind of engine and its braking mechanism

Abstract

The invention discloses an engine and a braking mechanism thereof. The braking mechanism comprises a cam shaft, a tappet, a gas distribution mechanism, a first valve and a second valve, wherein the tappet is driven by the cam shaft; the tappet is provided with a piston cavity, an oil supply pipeline and an oil leakage pipeline, the oil supply pipeline and the oil leakage pipeline communicate with the piston cavity, and a piston is arranged in the piston cavity; the gas distribution mechanism is used for controlling an exhaust valve to be opened or closed, and a braking gap is formed between the piston and the gas distribution mechanism; the first valve is used for controlling a braking oil duct to communicate with or separate from the oil supply pipeline; and the second valve is used for controlling the oil leakage pipeline to communicate with or separate from the outside. When braking is needed, oil is supplied in the braking oil duct, the first valve is controlled to be opened, the second valve is opened, when the piston moves to eliminate the braking gap, the first valve resets, the piston cavity forms a sealed cavity, accordingly, a braking cam drives the tappet to act, and the piston drives the gas distribution mechanism to act. Through the arrangement, the braking mechanism of the engine can be applicable to the under cam shaft, the space of a cylinder cover is not occupied, and arrangement is convenient.

Description

technical field [0001] The invention relates to the technical field of engines, and more specifically relates to an engine and a braking mechanism thereof. Background technique [0002] When the engine brakes, the nozzle stops fuel injection and controls the opening timing of its exhaust valve, turning the engine, which was originally a power output device, into an air compressor and a power consumption device. [0003] Please refer to figure 1 , figure 1 It is a schematic diagram of an engine braking mechanism in the prior art. When braking is required, voltage is applied to the brake control solenoid valve 1, the valve opens after the solenoid valve 1 is energized, the oil flows into the control valve 2 along the oil passage, the control valve 2 is moved upward by the oil pressure, and the internal spherical check valve of the control valve Leaving the valve seat, the engine oil flows into the upper oil passage, the main piston 3 is moved downward by the oil pressure, a...

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Problems solved by technology

[0004] However, this type of structure is only suitable for the form of the camshaft overhead, and the brake control structure occupies the space of the cylinder head, so it is difficult to arrange

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