An engine braking device

Abstract

Provided is an engine braking device. A cam shaft 1 of an engine is provided with an exhaust cam, a barking cam and a control cam. An exhaust rocker arm assembly 2 is provided with a control pull rod.A controller body 13 is provided with a tappet 7 and a push rod 9 of a V-shaped structure. Branches of the two sides of the push rod 9 are each provided with a step. The controller body 13 is provided with a drive shaft, one end of the drive shaft is provided with two drive pins, and the other end of the drive shaft is provided with a drive arm 142 and connected with the control pull rod. A resetpin 15 and an electromagnetic valve 17 are arranged on the two sides of the push rod 9 separately. When the engine needs to start a braking state, the electromagnetic valve 17 is electrified, the push rod 9 is pushed to swing towards one side of the reset pin, the steps on the push rod 9 push the drive shaft to rotate under action of the control cam so that the exhaust rocker arm can move to theposition where the exhaust rocker arm is in contact with the braking cam, and two-stroke braking is achieved; and when the engine needs to stop the braking state, the electromagnetic valve is switchedoff, the reset pin pushes the push rod to swing towards one side of the electromagnetic valve, the push rod pushes the drive shaft to rotate reversely in the same way so that the rocker arm can return to the position where the rocker arm is in contact with the exhaust cam.

Description

technical field [0001] The invention relates to an engine braking device, which belongs to the technical field of automobile engines, in particular to the technical field of engine braking. Background technique [0002] Engine braking technology has been around and used for a long time, especially in heavy-duty diesel engines. For heavy-duty trucks, when braking for a long time is required, such as when driving on a long downhill mountain road, the usual service braking device (brake) is easy to fail due to overheating when used for a long time, which greatly threatens driving safety. When a vehicle equipped with an engine braking device is running, the driver activates the engine braking device as needed. At this time, the engine cuts off the fuel supply, and the clutch remains connected to the power output end of the engine. The braking device realizes the braking function by changing the timing and lift of the valves, especially the exhaust valves, and temporarily conver...

AI Technical Summary

Problems solved by technology

[0004] At present, engine braking devices are mainly used in four-stroke heavy-duty diesel engines, and most of them are compression-release engine braking devices. Each gas stroke has an upward movement. Theoretically speaking, when the engine is turned into a braking state, the two strokes of compression and exhaust must be compressed and released to produce the highest braking power to the greatest extent. Compression-release engine braking devices, most of which cannot change the timing and lift of the exhaust valves used for normal engine operation during the exhaust stroke, therefore, can only be achieved in a working cycle. Will enter the cylinder during the compression stroke Compression release of the air produces a brake, and a brake cannot be achieved again during the exhaust stroke

Among the currently disclosed technologies that can achieve compression and release in both the compression and exhaust strokes to generate braking, multiple rocker arms or complex rocker arm or valve bridge structures are often required, the structure is complex, the cost is high, and the reliability of the work is also low. It has a shortpart

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