SU1476163A1 - Method and apparatus for compression braking of four-stroke ic-engine - Google Patents

Abstract

The invention makes it possible to reduce overall dimensions and increase engine life. The camshaft 1 is driven by the crankshaft 2 through a two-speed gearbox with a gear ratio of 1: 2 for engine operation in the main mode and 1: 1 for compressive braking. The gears of the gearbox are switched using a twin clutch 10.18 with friction mechanisms 20.21 synchronization and toothed clips 22.23. The fuel supply to the cylinders is stopped and the valve timing is changed by rotating the cam shaft 1 with respect to the crankshaft 2 by the angle at which the start of opening the exhaust valve corresponds to the position of the piston near the upper dead center. The speed of rotation of the shaft 1 is set equal to the speed of rotation of the shaft 2. 2 sec. f-ly, 2 ill.

Description

The invention relates to mechanical engineering and can be used in engine-building.

The aim of the invention is to provide the possibility of reducing the size and increasing engine life.

FIG. 1 shows a diagram of an apparatus for carrying out the method with a spool position corresponding to the main engine mode; FIG. 2 shows the position of the spool in the engine compression braking mode;

Device for compression. deceleration of a four-stroke internal combustion engine with shutdown of fuel supply to the working cylinders contains a controllable cam shaft 1 with a gear drive from the crankshaft 2 and a hydromechanical control system with a pump (not shown), pipelines 3-6, a spool 7 and control cylinders 8 and 9, the latter being formed by the working cavity of the switching clutch 10, the pipeline 3 is connected to the pump, the pipeline 4 to the drain tank (not shown), through the pipeline 6

the required angular position of the camshaft with respect to the crankshaft when the engine is operating in the main mode and in the braking mode. The clutch 10 makes a rigid connection of the camshaft 1 to the gear 14 in the absence of fluid pressure in the cylinder 9 under the influence of the spring 24, the clutch 18 connects the shaft 1 to the gear 17 when the working pressure is applied to the cylinder 9, while the spring 24 is compressed.

With the clutch 10 turned on, the cam shaft 1 rotates two times slower than the crankshaft 2, and the main engine operation mode is realized in a four-stroke cycle with the use of useful power at the output shaft. The position of the spool 7 corresponds in this case to that shown in FIG. 1. When the spool is switched to the position shown in FIG. 2, the clutch 10 is disengaged and the clutch 18 is turned on, connecting the rigidly cam shaft 1 to the gear 17. At the same time, the cam and crankshaft rotate at the same speed, and the latch 23 sets such their relative

the working fluid is supplied to the 30 position at which the beginning is open to the cylinder 8, which controls the supply of fuel to the engine working cylinders, the pipeline 5 through the supply device 11 feeds the cylinder 9 of the coupling 10, the spool 7 controls the supply of 35 working fluid to the cylinders 8 and 9. A gear drive is made in the form of a controlled two-speed gearbox with a gear ratio of 1: 2 for the engine to operate in the main mode 40 and 1: 1 for operation in the mode of compression braking, and the first mode is carried out when connecting the cams 1st shaft 1 with crankshaft

shaft 2 through gears 12-14 and known devices for compressing the engine, based on axial displacement of a two-stage camshaft for changing valve timing, shows that

This 10, the second when they are connected through gears 15-17 and the coupling 18, and the gear 19 serves to drive the high-pressure fuel pump.

The control system includes a double

coupling 10, 18 gearshifts re-reduction of the axial dimensions of the engine

duktora, equipped with frictional increase its resource due to

synchronization mechanisms 20, 21 and an increase in the wear-out working gear-jaw clips 22, 23. of the cam shaft.

Synchronization mechanism presented - 55

Claims (2)

It is a conical disc that presses 4 Formula invented to gears 14 and 17, respectively. 1. The compression method is braked with springs (not shown), and the four-stroke engine inside the gear clamps provide an early combustion that includes the discharge valve stop corresponding to the position of the piston near top dead center. Now, with each stroke of the piston from the top dead center to the bottom, alternately opening and closing first the exhaust valve and then the intake valve, and each time the piston moves from the bottom dead center to the upper one, both valves are closed and the air is compressed in the working cylinders. fuel supply. This case corresponds to the regenerative braking mode of the engine. Comparison of the proposed and fuel delivery to cylinders and variable valve timing by acting on a camshaft, kinematically connected to the crankshaft, working pistons and valves, characterized in that, in order to reduce the size and increase engine life, the camshaft is rotated relative to the crankshaft at an angle at which the beginning of the opening of the exhaust valve corresponds to the position of the piston near the top dead center, and give it a speed of displacement equal to the speed of rotation of the crankshaft. 2. Device for compression braking of a four-stroke engine ten m 15 476163 internal combustion with fuel supply to the working cylinders containing a controlled camshaft with a gear drive from the crankshaft and a hydromechanical control system with a pump, pipelines, spool and control cylinders, characterized in that the gear drive is designed as a controlled two-speed gearbox with a gear ratio of 1: 2 for the engine to operate in the main mode and 1: 1 for the work in the mode of compressive braking, and the control system includes a dual switch clutch soap has gear mechanisms provided with friction and synchronization toothed retainers.