JPH045696Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to an exhaust turbo supercharger for an engine.

(Prior technology) Conventionally, this technology has been introduced in the exhaust turbo supercharger of an engine in order to smoothly obtain sufficient boost pressure from the low speed range where the intake air amount is small to the high speed range where the intake air amount is large. For example, there is a technology that consists of multiple passages so that the passage area for exhaust gas is small in the low rotation range and large in the high rotation range.
This is well known as seen in Utility Model Application Publication No. 161139/1983.

However, in the case where the exhaust gas introduction passage is divided into low-speed and high-speed passages as described above, the formation of this passage curves the flow of exhaust gas and increases the contact area between the exhaust gas and the passage wall. As the exhaust pulsation is attenuated, the exhaust gas temperature decreases, which affects exhaust energy loss or exhaust gas purification performance.

In addition, if an on-off valve that closes the high-speed passage at low speeds is placed facing the mainstream of exhaust gas, the flow of exhaust gas will change significantly each time the on-off valve opens and closes, resulting in the above-mentioned reduction in exhaust energy. In addition to causing losses and fluctuations in exhaust resistance, if the on-off valve is formed to rotate downstream to open the high-speed passage, the exhaust pulsation acting on the on-off valve in the closed state becomes large. This rise in pressure causes the on-off valve to open, causing exhaust gas to leak to the high-speed side, resulting in a reduction in turbine efficiency.

(Purpose of the invention) In view of the above-mentioned circumstances, the present invention is designed to suppress the drop in exhaust temperature, especially in the low speed range, by configuring the exhaust gas introduction passage to the turbine with a low speed passage and a high speed passage. It is an object of the present invention to provide an exhaust turbo supercharger for an engine, which effectively transmits exhaust pulsation to the passage to efficiently drive a turbine, while ensuring a stable closed state of the high-speed passage by an on-off valve. It is something.

(Structure of the invention) The exhaust turbo supercharger of the invention has an exhaust gas introduction passage to the turbine formed by a low-speed passage and a high-speed passage, and an on-off valve that closes at low speed in the introduction part of the high-speed passage. The low-speed passage is arranged on an extension of the exhaust port of one cylinder of the engine, and the main flow of exhaust gas is formed to face the low-speed passage, and the on-off valve is placed in a side position. It is characterized in that it is installed so as to rotate toward the upstream side of the exhaust passage to open the high-speed passage using the exhaust passage as a fulcrum.

(Effect of the invention) According to the invention, the low-speed passage of the exhaust gas introduction passage to the turbine is provided on an extension line facing the exhaust port of one cylinder of the engine, and is formed so that the main flow of the exhaust gas is directed thereto. , at least the exhaust artery of the above-mentioned cylinder is effectively transmitted to the low-speed passage without being attenuated, improving the driving efficiency of the turbine, and suppressing the drop in exhaust temperature by reducing the heat release of the introduced exhaust gas. This is preferable in terms of exhaust purification performance and the like.

Furthermore, an on-off valve that closes the high-speed passage at low speeds is provided so as to rotate toward the upstream side of the exhaust passage using a side position as a fulcrum to open the high-speed passage, and the on-off valve is positioned away from the mainstream of exhaust gas. By installing the exhaust gas, there is little variation in the flow of exhaust gas due to the opening/closing operation of the on-off valve, reducing energy loss of exhaust gas and preventing increase in exhaust resistance. Furthermore, the on-off valve closes off the high-speed passage from the upstream side and the exhaust pressure acts in the direction of valve closing, so that even if there is a pressure increase due to the exhaust artery when the valve is closed, the on-off valve will remain closed. When maintained, stable operation can be obtained without causing exhaust gas leakage, and high turbine efficiency can be obtained as a whole.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.
Figure 1 shows the overall configuration of the engine.
An intake passage 4 and an exhaust passage 5 each having an exhaust turbo supercharger 3 are connected to each cylinder 2.

The intake passage 4 is connected from the upstream side to an air cleaner 6, an air flow meter 7, and a blower 3 of an exhaust turbo supercharger 3.
An intake manifold 11 including a throttle valve 9 and a surge tank 10 is arranged in this order and connected to each cylinder 2 to introduce intake air.

On the other hand, in the exhaust passage 5, exhaust gases from each cylinder 2 are collected in an exhaust manifold 13, and are discharged to the atmosphere through the turbine 3b of the exhaust turbo supercharger 3.

The exhaust turbo supercharger 3 has a turbine 3b
A partition wall 15 is provided in an exhaust gas introduction passage 14 that introduces exhaust gas into a low-speed passage 14a and a high-speed passage 14b, and an on-off valve 16 is installed at the introduction portion of the high-speed passage 14b. This on-off valve 1
Reference numeral 6 is formed so that the valve body thereof rotates toward the upstream side of the exhaust passage to open the high-speed passage 14b, using a position on the side opposite to the low-speed passage 14a as a fulcrum. In other words, the on-off valve 16 rotates from the upstream side and closes by pressing against the introduction part of the high-speed passage 14b, and when the valve is closed, exhaust pressure acts in the valve-closing direction.

An actuator (not shown) is connected to the on-off valve 16, and when the amount of intake air, that is, the amount of exhaust gas is small, it closes and directs the exhaust gas to the low-speed passage 14a.
On the other hand, when the amount of exhaust gas increases, the on-off valve 16 operates to open the high-speed passage 14.
Exhaust gas is also introduced from b.

Further, the low-speed passage 14a is arranged on an extension of the exhaust port 2a of the second cylinder 2 of the engine 1. That is, from this exhaust port 2a to the branch part 13a for the second cylinder of the exhaust manifold 13.
and a collective discharge part 13b are formed in a straight line, and furthermore, a low speed passage 14a of the exhaust gas introduction passage 14 is formed.
are connected in a straight line, and are formed so that the main flow of exhaust gas from the collective exhaust section 13b faces.

The exhaust gas discharged from the exhaust port 2a of the second cylinder 2 is introduced to the turbine 3b through the shortest distance, and the exhaust pulsation is transmitted in an undamped state with little energy loss, so that the turbine 3b is efficiently Driven. In addition, exhaust gas and passage wall 15
There is also less contact with the exhaust gas, and the drop in exhaust temperature is suppressed.
Furthermore, the main stream of exhaust gas does not operate on the opening/closing valve 16, and its opening/closing operation is not affected by exhaust pulsation.

[Brief explanation of the drawing]

FIG. 1 is an overall configuration diagram of an engine equipped with an exhaust turbo supercharger according to an embodiment of the present invention. 1... Engine, 2... Cylinder, 2a... Exhaust port, 3... Exhaust turbo supercharger, 3a... Blower, 3b... Turbine, 4... Intake passage, 5...
Exhaust passage, 13... Exhaust manifold, 14...
Exhaust gas introduction passage, 14a...Low speed passage, 14
b...high speed passage, 15...bulkhead, 16...open/close valve.

Claims (1)

[Scope of utility model registration request] In an exhaust turbo supercharger that supercharges intake air by driving a blower installed in the intake passage by a turbine installed in the exhaust passage of the engine, the exhaust gas introduction passage to the turbine is divided into a low-speed passage and a high-speed passage. An on-off valve that closes at low speeds is installed at the introduction part of the high-speed passage, and the low-speed passage is arranged on an extension of the exhaust port of one cylinder of the engine, and the low-speed passage is filled with exhaust gas. An exhaust turbo supercharger for an engine, characterized in that the main flow is directed toward the engine, and the opening/closing valve rotates toward the upstream side of the exhaust passage using a side position as a fulcrum to open the high-speed passage. .