JPH0439390Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) The present invention relates to an improvement of an exhaust turbo supercharging device that changes the passage area of the exhaust passage leading to the turbine nozzle depending on the operating condition of the engine. be.

(Prior art) Conventionally, in an exhaust turbocharging device, in order to obtain high turbine efficiency from the low speed range to the high speed range of the engine, the exhaust passage leading to the turbine nozzle is divided into a plurality of exhaust passages. Provided with an on-off valve that opens and closes at least one exhaust passage,
It is known that the opening/closing valve is used to change the passage area of the exhaust passage depending on the operating state of the engine.

For example, the device disclosed in Japanese Utility Model Publication No. 1230/1983 is configured to be able to adjust the area of the exhaust passage by providing a valve body that opens and closes a part of the exhaust passage, and
By providing a valve stem that opens and closes the vent hole in this valve body, and by moving the valve stem to open the vent hole at the beginning of the opening operation of the valve body, resistance to the exhaust pressure that acts when the valve body opens the valve body. The valve body is operated to open against the exhaust pressure while easing the force.

However, with the above-mentioned valve body and valve stem, etc., the high temperature exhaust gas comes into direct contact with them when the valve body is closed, and the structure becomes complicated to provide heat resistance. When the turbine is closed, exhaust pressure comes into contact with the back surface of the turbine, which increases ventilation resistance, making it impossible to improve turbine efficiency much.

(Purpose of the invention) The present invention has been made in view of the above points, and it is possible to easily open and close the on-off valve without installing a valve stem etc. that is easily affected by the heat of high-temperature exhaust gas. It is an object of the present invention to provide an exhaust turbo supercharging device that prevents exhaust pressure from directly acting on the back surface of the on-off valve even when the on-off valve is closed, thereby preventing a decrease in supercharging efficiency.

(Structure of the invention) The present invention divides the exhaust passage from the exhaust manifold to the turbine nozzle into a plurality of exhaust passages, provides an on-off valve at the branching part to each exhaust passage, and adjusts the on-off valve according to the operating state of the engine. In an exhaust turbo supercharging device that opens and closes at least one exhaust passage by oscillating displacement of A guide member is provided to guide the passage, and a shaft member serving as a swing fulcrum of the on-off valve is provided on the wall surface of the peripheral wall of the exhaust manifold on the side of the exhaust passage that is closed by the on-off valve, and the on-off valve is in an open state. A recessed portion is provided in which the guide member is accommodated when the guide member is placed.

With this configuration, when the on-off valve is closed, the exhaust gas is guided by the guide member to another open passage, thereby preventing exhaust pressure from directly acting on the back surface of the on-off valve. be.

(Example) FIG. 1 is an overall view of an exhaust turbocharger according to the present invention, and FIG. 2 is a sectional view of an exhaust gas introduction part to the turbocharger.

The exhaust turbo supercharging device 1 includes an engine main body 2
A turbo supercharger 4 into which exhaust gas from the turbo supercharger 4 is introduced via an exhaust manifold 3;
It has a valve device 5 that changes the passage area of exhaust gas supplied in the direction of the arrow.

The turbo supercharger 4 includes a turbine casing 6 that incorporates a turbine wheel that is rotationally driven by exhaust gas, and a compressor casing that incorporates a compressor wheel that is rotationally driven by the turbine wheel and pressurizes intake air. 7 are connected via a center casing 8. The turbine casing 6 has an exhaust passage 9 leading to a turbine nozzle that blows exhaust gas to the turbine wheel, and this exhaust passage 9 is divided into a first exhaust passage 11 and a second exhaust passage 12 by a partition 10. This branched portion is connected to the exhaust manifold 3.

A second exhaust passage 1 is provided at the branch part of the exhaust passage 9.
A valve device 5 for opening and closing 2 is provided. This valve device 5 includes an on-off valve 13 that swings between a closed state and an open state of the inlet of the second exhaust passage 12, and a valve support 14 that supports this on-off valve 13. We are prepared. This valve support body 14 is rotatably attached to the wall surface of the exhaust manifold 3 by a shaft member 15, and the opening/closing valve 1 is attached to this shaft member 15.
An actuator 16 that operates to open and close 3 is connected via a link member 17. The actuator 16 is configured as a diaphragm-type pressure-responsive mechanism in which the operating rod 18 is moved forward and backward in response to air pressure that is supplied and controlled according to the operating state of the engine, and when the engine is at low speed, it is indicated by the solid line in FIG. 2. The inlet of the second exhaust passage 12 is closed by the on-off valve 13 as shown in FIG. It is composed of

A guide member 19 is protruded from the back surface of the on-off valve 13 to guide exhaust gas toward the first exhaust passage 11 when the on-off valve 13 closes the second exhaust passage 12. That is, the guide member 19 is
When the on-off valve 13 is in the closed state, the exhaust manifold 3 stands up from a position corresponding to the partition wall 10.
Exhaust gas passing through the exhaust manifold 3 is guided by the protrusion 20 and guide member 19 to the first exhaust passage 11. It is now being guided to the side. In addition, the on-off valve 13
In the open state, the guide member 19 is configured to be housed in a recess 21 formed along the protrusion 20.

In the above configuration, when the engine is in a low speed operating state, the on-off valve 13 of the valve device 5 controls the second
The inlet of the exhaust passage 12 is closed to narrow the exhaust gas passage area and increase the flow velocity of the exhaust gas. Furthermore, when the on-off valve 13 is in the closed state, the exhaust gas is guided toward the first exhaust passage 11 by the guide member 19, which effectively prevents exhaust pressure from acting on the back surface of the on-off valve 13. Can be suppressed. Therefore, it is possible to prevent a decrease in turbine efficiency due to an increase in ventilation resistance of exhaust gas when the engine is running at low speed, and when the engine shifts to a high-speed operation state, the on-off valve 13 can be closed without being affected by the exhaust pressure. can be opened smoothly.

In this way, by providing the guide member 19 in the on-off valve 13, the on-off valve 13 can be opened smoothly by eliminating the influence of exhaust pressure, so unlike conventional devices, a vent hole is formed in the valve body. However, by moving the valve stem that passes through this vent hole and opening the vent at the beginning of the opening operation of the valve body, we have created a complex configuration that alleviates the resistance force of exhaust pressure that acts when the valve body opens. It is not necessary to adopt the valve device 5.
The structure of can be simplified. Moreover, since the connecting portion between the on-off valve 13 and its valve support 14 can be prevented from being affected by the heat of high-temperature exhaust gas, the configuration can be further simplified.

Further, a recess 21 is formed in the wall surface of the exhaust manifold 3 on the second exhaust passage 12 side, and the on-off valve 13
Since the guide member 19 is configured to be accommodated in the recess 21 when the on-off valve 12 is in the closed state, the flow of exhaust gas is effectively prevented from being obstructed by the guide member 19 when the on-off valve 12 is in the open state. can be prevented.

Note that various actuators can be used instead of the diaphragm actuator 16 as the operating mechanism of the on-off valve 13, and the actuator can be operated by directly detecting the flow rate of exhaust gas, the amount of intake air of the engine, or the engine rotation speed. The activation timing may be controlled.

(Effects of the invention) As explained above, in the present invention, a part of the exhaust passage is closed by an on-off valve when the engine runs at low speed, and the exhaust gas is opened by a guide member provided on the back of the on-off valve. Since it is guided to another exhaust passage, it is possible to effectively control the exhaust pressure acting on the back surface of the on-off valve. Therefore, good turbine efficiency can be obtained by preventing large ventilation resistance from acting in the closed state of the on-off valve, and the engine can shift from a low speed state to a high speed state without adopting a complicated configuration. This has the effect of eliminating the influence of exhaust pressure and allowing the on-off valve to open smoothly.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing an embodiment of an exhaust turbocharger according to the present invention, and FIG. 2 is a sectional view showing the main parts of the present invention. 1... Exhaust turbo supercharging device, 4... Turbo supercharger, 9... Exhaust passage, 11... First exhaust passage,
12...Second exhaust passage, 13...Opening/closing valve, 15
... Shaft member, 19 ... Guide member, 21 ... Recess.

Claims (1)

[Scope of utility model registration request] The exhaust passage from the exhaust manifold to the turbine nozzle is divided into a plurality of exhaust passages, an on-off valve is provided at the branching point to each exhaust passage, and the on-off valve is oscillated according to the operating state of the engine.
In an exhaust turbocharger that opens and closes at least one exhaust passage, on the back of the on-off valve,
A guide member is provided to guide the exhaust gas to another exhaust passage when the exhaust passage is closed by the on-off valve, and a guide member is provided on the peripheral wall of the exhaust manifold on the side of the exhaust passage that is closed by the on-off valve. 1. An exhaust turbo supercharging device comprising: a shaft member serving as a swinging fulcrum for an on-off valve; and a recess in which the guide member is accommodated when the on-off valve is in an open state.