JPS601227Y2 - Internal combustion engine exhaust turbo charger - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an exhaust turbocharger device for an internal combustion engine, in which part or all of the exhaust gas that has exited the combustion chamber is bypassed to the downstream side of the exhaust turbine by bypassing the exhaust turbine. Yo? This relates to the exhaust turbocharger device of Uchitsubo Eki, which aims to improve fuel efficiency, improve the durability of the exhaust turbocharger device, and reduce harmful exhaust gases.8.
1 Conventionally, in the exhaust gas turbocharger system of an internal combustion engine, a wastegate is generally used as a method to pass the exhaust gas to the downstream side of the UF% turbine without passing it through the exhaust turbine. ing.

This waist gate is activated by the intake pressure after the intake compressor, and when the intake pressure after the intake compressor exceeds a certain high pressure.

A wastegate valve installed in the exhaust system is opened to allow some of the exhaust gas to escape downstream of the exhaust turbine to prevent damage to the exhaust turbocharger and engine overload due to exhaust clogging.

For example, in JP-A-53-146024, the exhaust gas flowing to the turbocharger is bypassed using two valves: one operated by intake pressure, and another valve operated by accelerator opening, that is, load. The technology to do this is shown.

A similar technique is also described in Japanese Unexamined Patent Publication No. 54-1082R.

However, in the known technology of Goret et al., the higher the intake pressure, the higher the exhaust displacement, and the more the accelerator is pressed, the higher the bypass exhaust volume becomes.As a result, the exhaust bypass volume increases relative to the rotation speed. The pumping loss increases significantly at full load and at high rotational speeds.

Also, the valve may open under partial load, so
Acceleration becomes worse.

Japanese Unexamined Patent Publication No. 55-29033 proposes electronic control of a turbocharger, but although electronic control can suitably perform a wide range of control using a function generator program, it is not as effective as mechanical control. ≧ Therefore, the purpose of the present invention is to reduce the pumping loss at high engine speeds without unnecessary exhaust bypass at partial loads. Located in providing engine exhaust turbocharger equipment.

According to the present invention, in an exhaust turbocharger device for an internal combustion engine, a passage is provided to bypass the turbine of the exhaust turbocharger, and a control valve is provided in the middle of the bypass passage to bypass the exhaust according to the engine load. The control valve is equipped with a diaphragm, and the upper chamber of the diaphragm is provided with a spring having an acting force according to the load, and the lower chamber thereof is connected to an intake pressure communication pipe on which intake pressure acts.

Therefore, even if the load (accelerator opening) increases, the control valve operates based on the balance between the spring force and the intake pressure.

In the low speed range, the control valve is closed and exhaust bypass is not performed.

However, when the intake pressure increases as the rotational speed (speed) increases, the control valve opens by the amount that exceeds the spring force.

This spring force is related to the load, so if the load is large, the control valve will be difficult to open, but the higher the intake pressure is, the more the control valve will open.

Therefore, even with high loads, the amount of bypass is not large in the high speed range.

As a result, the intake pressure decreases, reducing pumping resistance.
Furthermore, even when the load is low, the control valve always closes when the load is large, resulting in good acceleration.

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is an explanatory diagram showing an overview of the present invention, and FIG. 2 and the following are graphs showing the effects.

In Fig. 1, the cylinder head 1 of the engine has an intake pressure of 2
, an exhaust pipe 3 are attached, and each pipe is provided with an intake compressor 5 and an exhaust turbine 6 to constitute an exhaust turbocharger.

An exhaust bypass pipe 7 is arranged parallel to the exhaust v3, and an exhaust bypass control valve 8 for adjusting the flow rate is provided in the vice pipe.

This exhaust bypass control valve 8 is divided into an upper chamber 10 and a lower chamber 11 by a diaphragm 9.

Upper chamber 1.1 Old, spring 12 is energized, fuel adjustment frame 13. A force called PL is acting downward.

Further, an intake pressure communication pipe is attached to the lower chamber 11 to communicate with the intake pressure 2, and the intake pressure PB acts thereon.

A shaft 15 is attached to the ram 9, and a valve 16 is provided at the tip of the shaft 15.

Therefore, the spring force PL and the intake pressure PB are linked to the load.
The valve 16 is controlled by both functions to bypass the exhaust gas.

FIG. 2 shows the load on the horizontal axis and the spring force PL on the vertical axis, and the spring force acts as a larger force as the fuel adjustment frame 13 is pushed deeper (the higher the load).

In Figure 3, the horizontal axis is the engine speed N, and the vertical axis is the intake pressure P.
In the graph taken from B, the intake pressure PB is larger for the high-load bird even at low load l, 1 uphill, and furthermore, the difference is smaller at lower speeds, and the difference increases as the speed increases, and the absolute value also increases. There is.

The load is set at one point A as shown in Figure 2, and the upper chamber is 10.
A spring force PLA that pushes the diaphragm 9 downward acts on the diaphragm 9 .

On the other hand, although the intake pressure PB acts on the lower chamber 11, in the low speed range it is smaller than the spring force PLA acting on the upper chamber, so the exhaust bypass control valve remains closed and bypass is not performed.

However, as the speed increases, the intake pressure decreases,
When the lotus degree becomes NA1 in FIG.

Due to the action of the excess force (PBA in Figure 4), the valve 16 is released and the exhaust gas is bypassed.

As a result, the amount of exhaust gas passing through the exhaust turbine 6 decreases, and the rotational force of the exhaust turbine 6 and further the intake compressor sensor 5 decreases.

Therefore, the amount of intake air decreases, the intake pressure PBA also decreases, and ultimately becomes stable at PLA.

The same can be said in the low speed range and the high speed range, and the spring force Pi, j, PL27 and intake pressure PB are constant values depending on the load.

Note that the constant pressure value maintained for this load is ′
)<N "It is possible to freely choose by changing the size of 2.

If you enumerate the effects of this invention, you will be happy.

(1) Exhaust turbine 6 and intake compressor 5
It is possible to reduce unnecessary operation and improve durability.

(2) It is possible to reduce the intake and exhaust resistance of the engine and improve fuel efficiency.

□(3) The effect of reducing the amount of intake air can reliably reduce the amount of harmful gas components emitted per unit time.

(4) Due to the reduction in the amount of intake air, the cylinder pressure is also reduced, and the life of engine-related parts such as pistons, cylinder liners, crankshaft metals, etc. can be extended.

In Figure 5, the horizontal axis shows the load, the vertical axis shows the output F, the intake pressure PB,
This is a graph showing the change in the dotted line A, which shows the characteristics of the present invention, compared to the solid line B, which shows the characteristics of the conventional device, when the harmful gas NOx is taken, and the above-mentioned effect is also supported by this experimental result. .

Note that if a large amount of exhaust bypass is performed in a high load range where a large amount of fuel is supplied, the amount of intake air will be insufficient, impairing optimal combustion.

Therefore, it is best to minimize exhaust bypass in high load ranges, and to increase the amount in low load ranges where the amount of fuel supplied is small.

In this embodiment, as mentioned above, the spring force PL corresponding to the load is generated mechanically by the combination of the fuel adjustment rod 13 and the spring 12, but it can also be generated by various other methods such as electrically and fluidly. A similar effect can be obtained.

In the embodiment, the intake pressure PB is also handled directly, but it is naturally possible to use other means.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing an embodiment of the present invention, FIG. 2 is a graph showing the relationship between load and spring force, and FIG. 3 is a graph showing the relationship between speed, load, and intake pressure in a conventional device. FIG. 4 is a graph similar to FIG. 3 according to the present invention, and FIG. 5 is a graph showing the effects of the present invention in comparison with a conventional device. 2...Intake pipe, 3...Exhaust pipe, 4...
...Exhaust turbocharger, 5...Intake compressor, 6...Exhaust turbine, 7...
...Exhaust bypass pipe, 8...Control valve, 9.
...Diaphragm, 10...Upper chamber, 11
...Lower chamber, 12...Spring, 16...
···valve.

Claims (1)

[Scope of utility model registration request] In an exhaust turbocharger device for an internal combustion engine, a passage that bypasses the turbine of the exhaust turbocharger is provided, and a control valve is provided in the middle of the bypass passage to bypass the exhaust according to the load of the engine.1. The control valve is equipped with a diaphragm, and the upper chamber 1 of the diaphragm has a spring having an acting force according to the load, and the lower chamber is connected to an intake pressure communication pipe on which the intake pressure acts. Internal combustion engine exhaust gas, charger device.