RU2008457C1 - Exhaust system of internal combustion engine - Google Patents

Abstract

FIELD: mechanical engineering. SUBSTANCE: exhaust system has exhaust manifold connected with engine cylinder and attachment fitted for sliding on manifold. Exhaust manifold and attachment have, respectively, longitudinal and inclined slots. Installed for axial travel in exhaust manifold is piston whose head has conical cavity. Base of cone points to engine cylinder side. EFFECT: enhanced efficiency. 2 cl, 2 dwg

Description

 The invention relates to the field of engineering, in particular to the engine, and in particular to the device of pipelines with adjustable effective length for two-stroke internal combustion engines.

 In two-stroke internal combustion engines, it is necessary to improve the cleaning of the cylinder from exhaust gases after opening the exhaust window to create a reduced pressure in the exhaust pipe, and before closing the window - to increase the pressure in order to delay the exit of the air-fuel mixture into the exhaust pipe and increase the filling ratio.

 Known exhaust system of the internal combustion engine, containing an exhaust pipe connected to the engine cylinder with a diffuser installed therein, which is rigidly connected to the cylindrical part, and a confuser mounted in the spacer with the possibility of longitudinal movement. By moving the confuser, the time of arrival of the compression wave to the exhaust window is controlled depending on the engine speed [1].

 The disadvantage of this exhaust system is the inability to control the time of arrival of the rarefaction wave to the exhaust window, because the diffuser is mounted rigidly. In addition, the dimensions and mass of the system are larger, because the maximum diameter of the confuser, diffuser, and the cylindrical part to be joined is at least two times the diameter of the pipeline. Thus, the system provides the engine with the best parameters at only one engine speed mode and has increased dimensions and weight.

 The closest technical solution to the invention is the internal combustion engine system, which consists of a pipeline connected to the cylinder of the engine with a longitudinal slot and mounted on it with the possibility of rotation of the cylindrical nozzle with an inclined slot. The operation of the system is based on the longitudinal movement of the window formed as a result of crossing the longitudinal and inclined slots of the pipeline and the nozzle depending on the angle of rotation of the nozzle, thereby achieving control of the wave propagation time from the outlet to the window and back [2].

 The disadvantage of the prototype is the fact that part of the air-fuel mixture leaving the exhaust pipe is lost when the engine cylinder is purged, since the prototype does not provide for the generation of a pressure wave behind the outlet window in the pipeline at the end of the purge. Therefore, the use of such an exhaust system is impractical for two-stroke ICEs.

 The aim of the invention is to increase efficiency.

 This goal is achieved by the fact that in the exhaust system, consisting of a pipeline connected to the cylinder of the engine with a longitudinal slot and mounted on it with the possibility of rotation of the cylindrical nozzle with an inclined slot, the pipeline is equipped with a piston mounted with the possibility of longitudinal movement, while the piston side facing engine can be made in the form of a cone.

 In contrast to the prototype in the inventive exhaust system, in addition to changing the length of the pipeline by moving the window and thereby changing the time of arrival of the rarefaction wave to the exhaust window, it is possible to change the length of the pipeline by longitudinal movement of the piston, changing the time of arrival of the compression wave. Such organization of movement in the exhaust pipe allows more efficient use of wave processes and significantly increase the filling coefficient in various modes.

 It is known the use of devices with a variable length of the pipeline in order to create a vacuum in it and the use of pistons with various final effects, and the movable piston, one machine of which is made in the form of a confuser, was not used in the previously declared exhaust systems, as well as a combination of these devices and a new claimed feature namely, the reflection of waves from a movable piston and a piston, the wall of which is made in the form of a confuser, which increases the length of the reflected wave. Using a combination of known devices and a new feature allows you to get a new positive effect and a new property in the inventive exhaust system of the internal combustion engine. A new positive sum-total effect is due to the fact that the energy of two types of waves and their independent regulation are simultaneously used, which is a new property.

 In FIG. 1 shows the inventive exhaust system of the internal combustion engine; in FIG. 2 is a section AA in FIG. 1.

 The exhaust system of the internal combustion engine comprises an exhaust pipe 1 connected to the engine cylinder, provided with a longitudinal slot 2, a cylindrical nozzle 3 with an inclined slot 4, and a movable piston 5 installed in the pipe 1.

 The system operates as follows. The compression wave resulting from the opening of the exhaust body moves along the pipe 1 in the direction of the piston 5. When the wave reaches the section of the pipeline with the window formed as a result of the coincidence of the longitudinal slot 2 and the inclined slot 4, this wave interacts with the window, resulting in a wave rarefaction, moving in the opposite direction to the exhaust element, and a compression wave, moving to the piston 5. The rarefaction wave, approaching the exhaust element, reduces the pressure behind it and improves the purge of the engine cylinder . The compression wave, reflected from the piston 5, moves in the opposite direction to the exhaust body, approaches the latter before closing and increases the pressure in the area of the exhaust window, which leads not only to prevent the ejection of the air-fuel mixture from the cylinder into the exhaust pipe, but also to the reverse flow mixture into the cylinder, increasing the filling ratio. Rotation of the nozzle 3 by a certain angle and thereby changing the position of the window along the length of the pipeline and the position of the piston 5 in accordance with the operating mode of the engine can be carried out by any regulator.

 Thus, the technical advantages of the inventive exhaust system are the possibility of a significant increase in pressure behind the exhaust body at the end of the purge and pressure drop during the purge process, which leads to a decrease in the release of fresh combustible mixture into the exhaust system and an increase in the filling of the engine cylinder.

 The declared exhaust system of the internal combustion engine allows the use of wave processes in the exhaust system to increase the fill factor and improve the purge of the engine cylinder, which leads to an increase in power and improved fuel economy of the engine. (56) 1. USSR author's certificate N 1460325, cl. F 02 B 27/04, 1987.

 2. Copyright certificate of the USSR N 544759, cl. F 02 B 27/00, 1976.

Claims (2)

 1. EXHAUST SYSTEM OF THE INTERNAL COMBUSTION ENGINE, comprising an exhaust pipe connected to an engine cylinder and movably mounted on a nozzle pipe, the exhaust pipe and nozzles having respectively longitudinal and inclined slots, characterized in that, in order to increase efficiency, an exhaust pipe is installed axial displacement piston.  2. The system according to p. 1, characterized in that in the piston bottom there is a recess in the form of a cone, the base of which is turned towards the engine cylinder.

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