KR20010059080A - A bypass system for improving low lebel torque ability of diesel engines - Google Patents

Abstract

PURPOSE: A bypass system for improving low speed output of a diesel engine is provided to reduce a sectional area of exhaustion of a turbine through improving bypass amount of exhaust gas in a high speed section. CONSTITUTION: An auxiliary diverged pipe(34) is installed from an exhaust gas inlet portion(26) of a turbine(20) to an exhaust gas outlet portion(28) to form an auxiliary diverged path. A bypass valve(36) is installed on the auxiliary diverged pipe for opening and closing the auxiliary diverged pipe by a portion of pressure operating a west gate actuator(32). The bypass valve receives pneumatic pressure through a compressor(22) by an auxiliary air supply pipe(40) to operate the west gate actuator. In case of the pneumatic pressure over a specific value, the auxiliary diverged pipe is opened. Herein, the turbine of a turbocharger(18) is rotated by exhaust gas through a discharge path(14) of an engine main body(12). Then, the compressor is rotated for compressing sucked air through an intake port(16). Then, the air is supplied to the engine main body while operating the west gate actuator through a main air supply pipe(38). In case of the actuator receiving pressure over a specific value, a main diverged pipe(30) is opened to increase amount of exhaust gas.

Description

BYPASS SYSTEM FOR IMPROVING LOW LEBEL TORQUE ABILITY OF DIESEL ENGINES}

The present invention relates to a bypass system for enhancing the low speed output of a diesel engine, and more particularly, to improve the low speed output performance by supplementing the exhaust path of the exhaust gas so as to further reduce the exhaust cross-sectional area of the turbocharger. A bypass system for reinforcing low speed output of an engine.

In general, diesel engines are installed in many transportation devices such as heavy trucks, buses, ships, etc., which require greater torque than gasoline engines, and turbochargers and inter coolers are used to generate more power. It also has an additional back.

As such, the structure of the diesel engine in which the turbocharger and the intercooler are mounted will be briefly described. As shown in FIG. 4, the air intake passage 114 that sucks air into the engine main body 112 including the cylinder head and the cylinder block, etc. An exhaust path 116 is formed to discharge the exhaust gas, and a turbocharger 118 having a turbine 120 and a compressor 122 rotated by the exhaust gas is provided in the intake passage 114 and the exhaust passage 116. It is mounted over, the intake passage 114 is equipped with an inter cooler 124 for cooling the high-temperature exhaust gas through the turbocharger 118.

However, a diesel engine equipped with such a turbocharger and an intercooler has a large amount of exhaust gas in the medium speed and high speed engine speed ranges of the engine, so that the engine speed of the turbine of the turbocharger also increases, so that more air can be supplied to the intake manifold. However, in the low speed range of the engine, the amount of exhaust gas is small, and the speed of the turbine of the turbocharger is also lowered. Therefore, even if the engine suddenly accelerates in idling state, the effect of turbo does not appear immediately. There was a downside.

Accordingly, as a device for increasing the turbine rotation at low speed by making the exhaust cross-sectional area of the turbine small, a west gate actuator 126 operated by high pressure air through the compressor 122 of the turbocharger 118 is added, By installing the branch pipe 128 opened and closed by the west gate actuator 126 from the exhaust gas inlet to the outlet of the turbine 120, the exhaust cross-sectional area of the turbine is not affected within the range of exhaust gas. A device capable of reducing the cost is being used.

However, as described above, the low speed output strengthening system of the diesel engine using only the west gate actuator has a certain limitation in the size of the exhaust cross-sectional area of the turbine, and thus, the output performance of the low speed section also has a problem of being difficult to be reinforced beyond a certain performance.

In other words, even if the west gate actuator fully opens the branch pipe in the high-speed rotation range, the amount of exhaust gas bypassed is limited. Therefore, if the exhaust cross-sectional area of the turbine becomes too small, the target output is far exceeded, and the emission of soot or NOx flows. The exhaust cross-sectional area of the turbine could not be made too small because the transmission durability could be reduced.

Accordingly, the present invention is to solve the above problems, an object of the present invention is to increase the bypass amount of the exhaust gas in the high speed section in the diesel engine having a turbocharger and inter cooler to reduce the exhaust cross-sectional area of the turbine The present invention provides a bypass system for enhancing the low speed output of a diesel engine that can enhance the output performance of the low speed section.

1 is a schematic diagram of a bypass system for enhancing low speed output according to the present invention;

2 is a perspective view of a bypass valve applied to the bypass system according to the present invention;

3 is a cross-sectional view of the bypass valve of FIG.

4 is a system diagram of a low speed power enhancement system according to the prior art.

<Description of the symbols for the main parts of the drawings>

12: engine body 18: turbocharger

20 turbine 22 compressor

24: inter cooler 30: main engine

32: West gate actuator 34: auxiliary branch pipe

36: bypass valve 38: main air supply pipe

40: auxiliary air supply pipe

The present invention for achieving the above object,

A turbocharger having an engine body, a turbine rotating by exhaust gas and a compressor, an inter cooler for cooling the high temperature exhaust gas through the turbocharger, and exhaust gas from the exhaust gas inlet to the outlet of the turbine of the turbocharger. In the low speed output strengthening system of a diesel engine including a main engine to bypass and a west gate actuator that opens and closes the main engine by being operated by high pressure air through a compressor of a turbocharger,

An auxiliary branch pipe separately from the main branch pipe to form an auxiliary branch path from the exhaust gas inlet to the outlet of the turbine of the turbocharger; Bypass valve for strengthening the low-speed output of the diesel engine comprising a; bypass valve which is operated by a part of the operating pressure for operating the west gate actuator is installed in the auxiliary branch pipe to open and close the auxiliary branch pipe Provide a pass system.

Hereinafter, with reference to the accompanying drawings an embodiment of the present invention that can specifically realize the above object will be described.

Referring to Figure 1, a preferred embodiment of a bypass system for enhancing the low speed output of a diesel engine according to the present invention is shown.

The bypass system adds a separate auxiliary branch path to the conventional low speed output enhancement system so that the exhaust gas can be discharged along the auxiliary branch path according to the present invention in addition to the conventional exhaust gas discharge path. It is possible to form smaller.

As described above, the conventional low speed output strengthening system is provided over the engine main body 12, the exhaust passage 14 and the intake passage 16 of the engine main body 12, and the exhaust gas in the exhaust passage 14. The turbocharger 18 which consists of the turbine 20 and the compressor 22 which rotates by this, the intercooler 24 which cools the high-temperature exhaust gas through this turbocharger 18, and the turbocharger 18 of Operated by a high pressure air through the main engine 30 to bypass the exhaust gas from the exhaust gas inlet 26 to the outlet 28 of the turbine 20 and the compressor 22 of the turbocharger 18. And a west gate actuator 32 which opens and closes the main engine 30.

According to the present invention, the auxiliary branch pipe 34 is formed from the exhaust gas inlet 26 of the turbine 20 to the outlet 28 of the exhaust gas in the conventional low speed power strengthening system. On the auxiliary branch pipe 34, a bypass valve 36 is provided which is operated by a part of the operating pressure for operating the west gate actuator 32 to open and close the auxiliary branch pipe 34.

The bypass valve 36 is formed by branching from the main air supply pipe 38 leading from the compressor 22 of the turbocharger 18 to the west gate actuator 32 to operate the west gate actuator 32. The air pressure through the compressor 22 is applied through the supply pipe 40, and when the air pressure acts at a predetermined size or more, the auxiliary branch pipe 34 is opened.

More specifically, the bypass valve 36, as shown in FIGS. 2 and 3, is coupled to the cover 42 and the cover 42 to form a space S therein and to one side. An upper body 44 provided with an auxiliary air supply pipe 40 connected to the main air supply pipe 38 so that a part of the operating pressure for operating the west gate actuator 32 is introduced into the space; It is formed integrally with the upper body 44, the lower portion is provided on the auxiliary branch pipe (34) having an inlet 48 for exhaust gas flow in one side and an outlet 50 for exhaust gas flow in the other side One side of the body 46 and the spring 54 supported by the cover 42 to open and close the inlet 48 of the lower body 46 by the operating pressure flowing into the upper body 44. By sliding the space S in the upper body 44, the other side being Comprises a rod (52) is formed so as to open and close the inlet port 48 of the body 46.

In the cover 42, a groove having a predetermined depth for guiding the spring 54 is formed and is fastened to the upper body by a bolt. The upper body 44 is supported from the lower body 46 by four support bars 56, and the lower body 46 is fastened to mount the bypass valve to the turbocharger 18 or the like. The hole 58 is formed in a fixed position.

In addition, the rod 52 slides through the upper body 44 and the lower body 46, and the side inserted into the upper body 44 from the rod 52 is a large diameter plate 60 of the upper body. It slides along the inner wall, and the side inserted into the lower body 46 interrupts the flow of the exhaust gas passing through the bypass valve as the small-diameter plate 62.

The bypass valve made as described above is not limited to the present embodiment, but may include all of the valve structures capable of acting in the same manner of operation and producing the same effect.

For example, the exhaust gas flow of the auxiliary branch pipe may be interrupted by configuring the opening / closing structure of the valve using a rod sliding in the body by the diaphragm.

The operation of the bypass system for improving the low speed output of the diesel engine according to the present invention made as described above is as follows.

First, when the turbine 20 of the turbocharger 18 is rotated by the exhaust gas discharged through the exhaust passage 14 of the engine body 12, the compressor 22 also rotates together, and the suction passage 16 is rotated. The intake air introduced through the compressor 22 is compressed while being rotated by the compressor 22, and the compressed air is introduced into the engine main body 12 through the intake passage 16 while the west gate actuator (via the main air supply pipe 38) 32) will be activated. When the predetermined pressure or more acts on the west gate actuator 32 through the main air supply pipe 38, the west gate actuator 32 opens the main injector 30 to increase the amount of exhaust gas discharged.

On the other hand, a part of the compressed air passing through the main air supply pipe 38 is introduced into the upper body 44 of the bypass valve 36 through the auxiliary air supply pipe 34, and a constant pressure into the upper body 44. When the above compressed air pressure is applied, the rod 52 rises over the elastic force of the spring 54, and the exhaust gas is discharged through the auxiliary branch pipe 34 while the auxiliary branch pipe 34 is opened. Will be.

As described above, since the exhaust gas is also discharged through the auxiliary branch pipe 34 in addition to the exhaust gas discharge amount of the main injector 30, the total exhaust gas discharge capacity may be increased, thereby exhausting the turbine of the turbocharger. The cross-sectional area can be made smaller.

According to the bypass system for enhancing the low speed output of the diesel engine of the present invention made as described above, the exhaust gas discharge capacity is increased, so that the emission of smoke or NOx and the transmission due to the excess of the target power in the high speed range are increased. The fall of durability can be prevented.

In addition, since the exhaust cross-sectional area of the turbine of the turbocharger can be made smaller, the starting power of the vehicle can be improved by increasing the output in the low speed rotational speed region, and the combustion performance is improved due to the increased amount of air at low speed, thereby improving fuel economy. can do.

Claims (2)

A turbocharger comprising an engine main body, a turbine and a compressor provided over the exhaust passage and the intake passage of the engine main body and rotating by the exhaust gas in the exhaust passage, an inter cooler cooling the high-temperature exhaust gas through the turbocharger; And a diesel engine including a main engine for bypassing the exhaust gas from the exhaust gas inlet to the outlet of the turbine of the turbocharger, and a west gate actuator that opens and closes the main engine by being operated by high pressure air through a compressor of the turbocharger. In the low-power output system of The low speed output enhancement system An auxiliary branch pipe that separates the main branch pipe from the exhaust gas inlet to the outlet of the turbine of the turbocharger; Bypass valve for strengthening the low-speed output of the diesel engine comprising a; bypass valve which is operated by a part of the operating pressure for operating the west gate actuator is installed in the auxiliary branch pipe to open and close the auxiliary branch pipe Pass system. The method according to claim 1, The bypass valve is A cover 42; Coupled to the cover to form a space therein, and connected to the main air supply pipe between the compressor and the west gate actuator so that a portion of the operating pressure for operating the west gate actuator into the space may be introduced into one side of the space. An upper body 44 on which an auxiliary air supply pipe is installed; A lower body 46 formed integrally with the upper body and provided on the auxiliary branch pipe and having an inlet through which exhaust gas flows in one side and an outlet through which exhaust gas flows out the other side; In order to be able to open and close the inlet of the lower body by the operating pressure introduced into the upper body, one side is supported by a spring supported by the cover to slide the space in the upper body, the other side to open and close the inlet of the lower body A rod 52 formed; Bypass system for enhancing the low speed output of a diesel engine, characterized in that comprises a.