JPS6245056Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to an improvement in a turbocharger that supplies pressurized intake air to an internal combustion engine.

In an internal combustion engine equipped with the above turbocharger,
Engine output can be increased by 20 to 30% compared to an internal combustion engine without a turbocharger.

However, even in such a turbocharger, the supercharging pressure only increases when the rotation speed reaches a high speed range, which is harmful to the engine.

As a measure to prevent this, normally, when the boost pressure exceeds a certain level, a waste gate provided in the bypass passage that communicates the gas inlet side and the gas outlet side of the turbine housing is opened to release some of the exhaust gas. It controls the boost pressure by letting it escape.

Specific structures conventionally adopted include, for example, the one disclosed in Japanese Utility Model Application Publication No. 132330/1983;
and those shown in Figure 1 (for which MTZ
(Motortechnishce-Zeitschrift) 43 (1982) 1
(shown on Pages 469 to 472 of 0), both of which can control the boost pressure, but in the former case, the back pressure downstream of the turbine is increased due to the structure, so the engine is in the low load range and There is a disadvantage that the pumping loss is large in the high-speed operation range and fuel efficiency deteriorates, and although the latter is more effective than the former due to its structure, because the opening degree of nozzle a is constant, There was a problem in that pumping loss could not be sufficiently reduced when the engine was in a low load range or high speed operating range. In addition, in FIG. 1, b is a bypass passage communicating with the gas inlet side of the turbine housing.

Therefore, in view of the above-mentioned problems, this invention was designed to obtain appropriate boost pressure over a wide range of speed and load ranges of the engine, and to sufficiently reduce pumping loss in the low load and high speed ranges of the engine. The purpose of this project is to provide a turbo supercharger that is capable of

Hereinafter, an embodiment of this invention will be described based on FIG. 2.

In the figure, 1 is a turbine 2 and a compressor 3.
The gas inlet side of the turbine housing 4 of the turbine 2 is connected to an exhaust manifold 5 of the engine, and the exhaust housing 6 is connected to the gas outlet side.
An intake duct 7 is connected to the inlet side of the compressor 3, and an engine intake duct 8 is connected to the outlet side.

The exhaust housing 6 has a bypass passage 9 that communicates with the exhaust manifold 5 (integrally formed), and an ejector 10 formed at the confluence of the bypass passage 9 has a cylindrical structure that is movable in the thrust direction. A waste gate valve 11 is provided.

The wastegate valve 11 is moved in the thrust direction by the rotation of a pinion 13 that meshes with a rack 12 formed on its outer circumferential surface. Also, pinion 1
3 is rotated by the reciprocating motion of an actuator (air cylinder) 15 connected via a link mechanism 14. Such a pinion 13 is installed in a recess 16 provided in the discharge housing 6.

Further, an inclined outer circumferential seat surface 17 is provided at the tip of the waste gate valve 11, and this outer circumferential seat surface 17 is used for the ejector 1 when closing the bypass passage 9.
An inclined inner circumferential seat surface 18 provided at the tip of the
join with.

The actuator 15 is connected to a controller 19 and is actuated by an output signal from the controller 19.
The wastegate valve 11 is moved in the thrust direction via the valve to open and close the bypass passage 9. When opened, it becomes a variable nozzle, and the amount of bypass of exhaust gas is adjusted by the distance between the outer circumferential seat surface 17 and the inner circumferential seat surface 18.

For example, signals representing engine torque and engine speed (T, N, respectively) are input to the controller 19, and as shown in FIG. status), half-open, and fully closed.

In addition, the output signal of the controller 19 is transmitted to the actuator (air cylinder) of the bypass valve 21 installed in the bypass passage 20 on the side of the compressor 3.
22, and the bypass valve 21 is linked with the waste gate valve 11. That is, the bypass valve 21 is fully opened when the wastegate valve 11 is in the fully open state, and fully closed when the wastegate valve 11 is in the half-open and fully closed states, thereby adjusting the amount of bypass intake air in the bypass passage 20.

With the above configuration, the actuators 15 and 22 expand and contract according to the operating state of the engine, thereby adjusting the opening degrees of the waste gate valve 11 and the bypass valve 21, thereby bypassing the bypass passages 9 and 20. The amount of exhaust and intake air is controlled. Therefore, appropriate boost pressure can be obtained over a wide engine speed range and load range, and sufficient boost pressure can be obtained even in low speed and high load ranges, and pumping loss is small in low load ranges, resulting in good fuel efficiency. and high speed/
The boost pressure does not become excessive even in a high load range, and since the main flow in the ejector 10 is sucked by the energy of the bypass flow, the back pressure downstream of the turbine 2 is reduced, thereby reducing pumping loss. Therefore, fuel efficiency is improved.

4 and 5 show a turbocharger 1' installed in a multi-cylinder engine 23. In this case, since the exhaust manifold 5' is configured for each cylinder so that the exhaust does not interfere with the partition wall 5'b, the bypass passage 9' provided in the exhaust housing 6' is also connected to the exhaust passage 5'a of the exhaust manifold 5'. There are multiple locations depending on the number of locations, and
Inside the ejector 10', a partition wall 24 defines chambers 25, 26 corresponding to each bypass passage 9'. Therefore, the exhaust gas flowing through each exhaust passage 5'a of the exhaust manifold 5' does not interfere with exhaust gas inside the exhaust housing 6'. Although the pinion 13' is designed to be rotated by the step motor 27, it may be rotated by the actuator 15.

In summary, the turbocharger according to this invention has a bypass passage that communicates with the gas inlet side of the turbine housing on the gas outlet side of the turbine housing, and an ejector that is formed at the confluence of the bypass passage. The ejector is provided with a cylindrical waste gate valve that closes the bypass passage when the outer circumferential seat surface of the tip joins the inner circumferential seat surface of the ejector and opens the bypass passage when the tip moves away from the inner circumferential seat surface. Therefore, as described in the embodiment, if the waste gate valve is opened and closed according to the operating condition of the engine, the pumping loss can be reduced when the engine is in the low load region and high speed operating region. is reduced, resulting in good fuel efficiency.

Although this invention has been described as a turbo supercharger, it can be similarly applied to an exhaust turbine of a turbo compound engine.

[Brief explanation of the drawing]

Fig. 1 is a vertical sectional front view showing a conventional discharge housing, Fig. 2 is a partially cutaway front view of an embodiment of this invention, Fig. 3 is an opening control diagram of the same waste gate valve, and Fig. 4 is a different one. A partially cutaway front view of the embodiment, and FIG. 5 is a sectional view taken along the line AA. In the figure, 1 and 1' are turbochargers, 4 is a turbine housing, 6 and 6' are exhaust housings,
9, 9' are bypass passages, 10, 10' are ejectors, 11 is a waste gate valve, 12 is a rack, 1
3, 13' are pinions, 14 is a link mechanism, 15
1 is an actuator, 17 is an outer peripheral seating surface, 18 is an inner peripheral seating surface, 24 is a partition wall, and 25 and 26 are chambers.

Claims (1)

[Claims for Utility Model Registration] (1) The gas outlet side of the turbine housing has a bypass passage communicating with the gas inlet side of the turbine housing, and the inside of the ejector formed at the confluence of the bypass passage is thrust. The cylindrical waste gate valve is provided with a cylindrical waste gate valve that closes the bypass passage when the outer circumferential seat surface of the distal end joins the inner circumferential seat surface of the ejector by pivoting in the direction, and opens the bypass passage when the distal end moves away from the inner circumferential seat surface. A turbo supercharger characterized by having a discharge housing installed. (2) The turbo supercharger according to claim 1, wherein the waste gate valve moves in the thrust direction by rotation of a pinion that meshes with a rack formed on the outer peripheral surface of the waste gate valve. (3) The turbo supercharger according to claim 2, wherein the pinion is rotated by an actuator connected via a link mechanism. (4) The turbo supercharger according to claim 2, wherein the pinion is rotated by a motor. (5) In the case where the ejector has a plurality of bypass passages, a chamber connected to each bypass passage is formed in the ejector by a partition wall. Machine.