KR20010048662A - An intake and exhaust apparatus of diesel engines for increasing torque in low r.p.m area - Google Patents

Abstract

PURPOSE: An intake/exhaust device for improving the output of a low speed section of a diesel engine is provided to prevent the turbo-lag phenomenon in a low speed area by flowing intake air or exhaust air directly without passing through a turbo charger or an intercooler in a low speed rpm section, thereby improving the engine output and providing uniform engine output through the all rpm areas. CONSTITUTION: An intake/exhaust device for improving the output of a low speed section of a diesel engine includes a compression air supply part(34,36) for supplying compression air to an intake manifold(26) of the diesel engine, intake parts(38,40,42,44) for directly connecting the compression air supply part with the intake manifold, and directly connecting an air cleaner(28) with the intake manifold, to be selectively operated for supplying the compression air and atmospheric air into the intake manifold directly without passing an intercooler(32), exhaust parts(46,48) for directly connecting an exhaust manifold(14) of the diesel engine to an exhaust pipe(22) for discharging exhaust gas of the exhaust manifold to the exhaust pipe directly without passing through a turbo charger(20), and a control part for supplying the compression air to the intake manifold via the intake part and directly discharge the exhaust gas to the exhaust pipe via the exhaust pipe in a low speed rpm area of the diesel engine.

Description

Intake and exhaust device for improving low speed section output of diesel engine {AN INTAKE AND EXHAUST APPARATUS OF DIESEL ENGINES FOR INCREASING TORQUE IN LOW R.P.M AREA}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an intake and exhaust device of a diesel engine, and more particularly, to a turbo-lag phenomenon in a low speed section occurring in a diesel engine having a turbocharger and an intercooler. The present invention relates to an intake and exhaust device for improving the output of a low speed section of a diesel engine capable of further improving output.

In general, diesel engines are installed in transportation devices that require greater torque than gasoline engines, such as large trucks, buses, and ships, and turbochargers and inter coolers are used to generate more power. It is also equipped with an additional.

An example of a diesel engine having a turbocharger and an intercooler as described above, for example, as shown in FIG. 2, is an intake air including an intake manifold 104 at upper and lower portions of an engine main body 102 including a cylinder head and a cylinder block. An exhaust system including a system and an exhaust manifold 106 is formed.

The exhaust system is a turbocharger 112 having an exhaust manifold 106, a turbine 108 and a compressor 110 installed behind the exhaust manifold 106 and rotated by exhaust gas. The muffler 116 or the like for reducing the noise of the exhaust gas discharged from the turbine 108 of the turbocharger 112 via the exhaust pipe 114.

The intake manifold 104 includes an air intake manifold 104, an air cleaner 118 for purifying foreign substances in the outside air, and the like, into the compressor 110 of the turbocharger 112, an intake manifold 104, Intake manifold is installed on the air inlet pipe 120 connecting the compressor 110 of the turbocharger 112 to cool the compressed high temperature and high pressure air to the low temperature and high pressure via the compressor 110 of the turbocharger 112. It consists of an intercooler 122 which supplies a fold.

As described above, the diesel engine having the turbocharger and the intercooler compresses the intake air using the exhaust gas passing through the turbocharger 112 to form high temperature and high pressure air, and cools the compressed air through the intercooler 122. This allows air to be introduced into the engine at a pressure higher than atmospheric pressure. In this way, when the high-pressure air is introduced, the engine may fill a large amount of air even in the same engine, and accordingly, increasing the injection amount of the fuel may further improve the output of the engine.

However, in the diesel engine having a turbocharger and an intercooler as described above, since the amount of exhaust gas is large in the medium speed and high speed engine speed ranges of the engine, the engine speed of the turbocharger turbine is also increased, and a larger amount of air flows into the intake manifold. Although the amount of exhaust gas is low in the low speed engine speed range of the engine, the engine speed of the turbine of the turbocharger is also lowered, so that the turbo does not immediately exhibit an effect even if it tries to accelerate rapidly in the idling state.

This slow operation of the turbo is called turbo-lag (turbo-lag) due to this turbo lag in the low-speed revolutions of the diesel engine with a turbocharger has a problem that the engine output is less than the conventional diesel engine.

Accordingly, an object of the present invention is to solve the above problems, and an object of the present invention is to provide a turbocharger and an intercooler by using a turbocharger by performing intake and exhaust operation by another operating mechanism in a low speed rotational speed region. The present invention provides an intake and exhaust device for improving the output of a low speed section of a diesel engine, which prevents a turbo lag phenomenon and improves the output even in a low speed region by using stored compressed air.

1 is a schematic diagram of an intake and exhaust system of a turbo-intercooler diesel engine to which an intake and exhaust device according to the present invention is applied;

2 is a schematic diagram of an intake and exhaust system of a turbo-intercooler diesel engine according to the prior art.

<Explanation of symbols for main parts of drawing>

12 engine body 14 exhaust manifold

16: Turbine 18: Compressor

20: turbocharger 22: exhaust pipe

24: muffler 26: intake manifold

28: air cleaner 30: air inlet pipe

34: air compressor 36: compression tank

38: first direction switching valve 40: first branch pipe

42: pressure reducing valve 44: second branch pipe

46: second direction switching valve 48: third branch pipe

50: electronic control unit

In order to achieve the above object, the present invention,

A diesel engine having a turbocharger driven by exhaust gas and an intercooler for cooling high temperature and high pressure compressed air through the compressor of the turbocharger, the compressed air supply unit for supplying compressed air to an intake manifold of the diesel engine Wow; An intake unit that directly connects the compressed air supply means and an intake manifold, and directly connects an air cleaner and an intake manifold so that compressed air and external air are supplied directly to the intake manifold without passing through the intercooler; An exhaust unit which is directly connected to an exhaust manifold of the diesel engine and an exhaust pipe so that exhaust gas of the exhaust manifold can be directly discharged to the exhaust pipe without passing through the turbocharger; And a control unit for controlling the operation such that the compressed air is supplied to the intake manifold through the intake unit in the low speed rotation speed region of the diesel engine, and controlling the operation so that the exhaust gas is discharged directly to the exhaust pipe through the exhaust unit. Provided is an intake and exhaust device for improving the output of a low speed section of a diesel engine.

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

1 shows an intake and exhaust system including an intake and exhaust device of a diesel engine according to a preferred embodiment of the present invention.

Referring to FIG. 1, a diesel engine having a turbocharger and an intercooler includes an engine main body 12 including a cylinder head and a cylinder block, an exhaust manifold 14 formed under the engine main body 12, and the exhaust air. A turbocharger 20 having a turbine 16 and a compressor 18 rotated by exhaust gas provided behind the manifold 14 and discharged from the turbocharger 20 via an exhaust pipe 22. The muffler 24 which reduces noise of exhaust gas, the intake manifold 26 formed in the upper part of the engine main body, and the foreign matter of the outside air to be sucked are purified and the compressor 18 of the turbocharger 20 is cleaned. Installed on the air inlet pipe 30 that connects the air cleaner 28 to be introduced into the air cleaner and the compressor 18 of the intake manifold 26 and the turbocharger 20 to cool the high temperature and high pressure air to low temperature and high pressure. It consists of an intercooler 32.

In the diesel engine made as described above, the intake and exhaust device according to the present invention prevents the occurrence of a turbo lag phenomenon by preventing the exhaust gas from passing through the turbocharger in a low speed rotational speed range, and simultaneously introduces compressed air into the intake manifold without the turbocharger. To improve the engine output at low speeds.

To this end, the intake and exhaust device according to the present invention has a compressed air supply unit 34, 36 which can supply compressed air separately from the turbocharger 20, and the compressed air and the external air from the compressed air supply unit and the air cleaner 28 Exhaust gas from the exhaust manifold 14 and the intake parts 38, 40, 42, 44 which operate to supply the gas directly to the intake manifold 26 without passing through the intercooler 32. Exhaust parts 46 and 48 which operate to be discharged to the exhaust pipe 22 directly to the muffler 24 without passing through are provided, and these devices are controlled to be controlled by the controller 50.

The compressed air supply unit is an air compressor 34 for compressing external air at high pressure to supply compressed air to the intake manifold 26, and a compression for storing a predetermined amount of high pressure air compressed by the air compressor 34. It consists of a tank 36.

The air compressor 34 is installed in the vehicle body and is driven by the diesel engine according to the present invention. The compressed air compressed by the air compressor 34 and stored in the compression tank 36 is about 5 kg / cm 2. Has a tooth.

The intake air intakes 38 and 40 allow the external air to flow into the intake manifold 26 and the compressed air intake air into the compressed air intake manifold 26 from the compressed air supply units 34 and 36. (42,44), the outside air intake portion is a first direction switching valve 38, which is installed on one side of the air inlet pipe 30 behind the air cleaner 28, and the first direction switching valve 38 A first branch pipe 40 branching from the first inlet pipe 40 to the intake manifold 26, wherein the compressed air intake unit is provided with a pressure reducing valve 42 provided on one side of the compression tank 36, and the pressure reducing valve ( And a second branch pipe 44 branching from 42 to the intake manifold 26.

The first direction switching valve 38 and the pressure reducing valve 42 are electronically operated valves. When the valves are turned on, the first direction switching valve 38 adjusts the flow direction of air to the air cleaner 28. ) To the first branch pipe 40, and the pressure reducing valve 42 reduces the compressed air of the compression tank 42 to a constant pressure value, for example, about 1.5 kg / cm &lt; 2 &gt; 44).

Accordingly, the intake manifold 26 is a mixture of the outside air through the first branch pipe 40 and the compressed air through the second branch pipe 44 is introduced in a larger amount than the intake air of a typical diesel engine. Air can be introduced.

The exhaust parts 46 and 48 serve to introduce the exhaust gas directly into the exhaust pipe 22 without passing through the turbocharger 20, and for this purpose, the second direction change is provided at the rear of the exhaust manifold 14. A valve 46 and a third branch pipe 48 branched from the second diverter valve 46 and directly connected to the exhaust pipe 22.

The second diverter valve 46 is an electronically operated valve in the same manner as the first diverter valve 38. When the second diverter valve 46 is turned on, the second diverter valve 46 is configured to control the flow direction of the exhaust gas from the exhaust manifold 14. By switching to the third branch pipe 48, exhaust gas is discharged to the exhaust pipe 22 instead of through the turbocharger 20 to prevent turbolag.

On the other hand, the operation of the intake and exhaust portion made as described above is controlled by the controller 50.

The control unit 50 may use an electronic control unit (ECU) 50 for controlling various electrical appliances of the vehicle by receiving the RPM, the water temperature, the opening degree of the throttle valve, and the like. The operation of the intake and exhaust device according to the present invention together is as follows.

First, referring to the case where the high speed speed range of the diesel engine, for example, the speed of the engine is 1,500 rpm or more, the controller 50 may turn off the first and second directional control valves 38 and 46 and the pressure reducing valve 42. As a result, the intake air and exhaust gas flow paths are controlled by the air cleaner 28, the air inlet pipe 30, the compressor 18 in the turbocharger, the intercooler 32, and the intake manifold. The inlet gas flows into the engine main body 12 along a path leading to 26, and exhaust gas flows along the path from the exhaust manifold 14 to the turbine 16 in the turbocharger to the exhaust pipe 22 to the muffler 24. It will be discharged to the outside.

Next, in the case where the low speed speed range of the diesel engine, for example, the speed of the engine is 1,500 rpm or less, the controller 50 causes the first and second directional control valves 38 and 46 and the pressure reducing valve 42 to be turned on. As a result, the intake air and the exhaust gas flow paths are controlled, and the intake air is compressed tank 36 → second branch pipe 44 → path of the intake manifold 26 and air cleaner 28 → The air inlet pipe 30 → the first branch pipe 40 → the intake manifold 26 flows into the engine main body 12, and the exhaust gas is exhaust manifold 14 → the third branch pipe 48 The exhaust pipe 22 is discharged to the outside along the path of the muffler 24.

As described above, the intake / exhaust apparatus according to the present invention can obtain an evenly improved output in the entire rotational speed region of the engine by dividing the high-speed rotational speed region and the low-speed rotational speed region to switch the flow direction of the intake and exhaust gas.

The low-speed section output improvement intake and exhaust device of the diesel engine according to the present invention made as described above is a low-speed region by allowing the intake and exhaust flow in the low-speed revolution section in the diesel engine having a turbocharger and intercooler without passing through the turbocharger and the intercooler It is possible to prevent the occurrence of the turbo lag phenomenon, and by forcibly introducing compressed air into the intake manifold, the engine output can be further improved, and the output can be improved evenly over the entire speed range.

Claims (4)

A diesel engine having a turbocharger driven by exhaust gas and an intercooler for cooling high-temperature and high-pressure compressed air through a compressor of the turbocharger, A compressed air supply unit for supplying compressed air to the intake manifold of the diesel engine; An intake unit which directly connects the compressed air supply unit with an intake manifold and directly connects an air cleaner and an intake manifold such that compressed air and external air are supplied directly to the intake manifold without passing through the intercooler; An exhaust unit which is directly connected to an exhaust manifold of the diesel engine and an exhaust pipe so that exhaust gas of the exhaust manifold can be directly discharged to the exhaust pipe without passing through the turbocharger; A control unit for controlling compressed air to be supplied to the intake manifold through the intake unit and controlling the exhaust gas to be immediately discharged to the exhaust pipe through the exhaust unit in a low speed rotational speed region of the diesel engine; Intake and exhaust device for improving section output. The method according to claim 1, The compressed air supply unit An air compressor 34 for compressing the outside air at a high pressure; Compression tank (36) for storing a predetermined amount of high-pressure air compressed by the air compressor; the low-speed section output improvement intake and exhaust device of the diesel engine, characterized in that consisting of. The method according to claim 1, The intake portion A first directional valve 38 installed at one side of the air inlet pipe behind the air cleaner to adjust the flow direction of the air, and from the first directional valve side so that the air can be supplied to the intake manifold An outside air intake unit formed of a first branch pipe 40 branched and directly connected to the intake manifold; A pressure reducing valve 42 installed at one side of the compressed air supply unit to reduce the compressed air, and branched from the pressure reducing valve side to be directly connected to the intake manifold so that the compressed air can be supplied to the intake manifold Compressed air suction portion consisting of a second branch pipe 44; intake and exhaust device for improving the output of the low speed section of the diesel engine. The method according to claim 1, The exhaust part A second diverter valve 46 installed at the rear of the exhaust manifold to regulate the flow of exhaust gas, and branched from the second diverter valve side so that the exhaust gas can be supplied directly to the exhaust pipe; An intake and exhaust device for improving output of a low speed section of a diesel engine, comprising a third branch pipe 48 directly connected to the pipe.