JP3386161B2 - Intake collector device for supercharged engine - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an intake collector device for a supercharged engine. 2. Description of the Related Art Generally, as shown in FIG. 3, an intake air a pressurized by an exhaust turbocharger 2 is taken into a racing engine 1 of a category using gasoline or methanol fuel, for example. An intake collector 4 is provided which distributes and supplies a to the combustion chamber 3 in each cylinder of the racing engine 1. The intake collector 4 is provided with a supercharging pressure limiting valve 5, and the intake air 4 pressurized by the exhaust turbocharger 2 does not rise above a certain pressure (limit pressure) due to the inflow of intake air a. It is controlled as follows. That is, the valve element 6 of the supercharging pressure limiting valve 5 is
When the pressure becomes higher than the limit pressure, the valve port 7 opens, and the intake a in the intake collector 4 is released to the atmosphere through the release hole 8 to control the pressure in the intake collector 4. [0004] The intake pressure in the intake collector 4 periodically fluctuates due to the pulsation of the supercharging pressure from the exhaust turbocharger 2. The pressure limiting valve 5 is operated to avoid an increase in pressure in the intake collector 4. However, at this time, the intake collector 4
Immediately thereafter, the intake air flow guided to each combustion chamber 3 in each cylinder of the engine 1 via the inlet manifold 9 decreases.
For this reason, engine output characteristics such as acceleration performance are degraded. The fact that the flow rate of intake air flowing to the combustion chamber 3 of the racing engine 1 decreases every time the boost pressure limiting valve 5 is operated is a major disadvantage for the racing engine. The present invention has been made in view of the above circumstances, and suppresses the opening operation of the supercharging pressure limiting valve.
Therefore, an object of the present invention is to provide an intake collector device for a supercharged engine that can reduce pressure fluctuations in an intake collector and prevent a decrease in engine output. The present invention takes in intake air pressurized by a supercharger into an intake collector, and distributes and supplies the intake air from the intake collector to each cylinder of the engine. In the intake collector device of the supercharged engine, a supercharging pressure limiting valve is installed in the intake collector to limit the pressure in the intake collector to a certain value or less, and the intake collector A pressure fluctuation mitigation mechanism for mitigating the pressure fluctuation in the intake collector by changing the volume in the collector is also provided. Therefore, according to the intake collector device of the supercharged engine according to the present invention, since the pressure fluctuation reducing mechanism is installed in the intake collector, the intake air boosted by the supercharger is supplied to the intake collector. Even if the pressure of this intake fluctuates,
The pressure fluctuation mitigation mechanism can keep the pressure fluctuation inside the intake collector constant. For this reason, the valve opening operation of the supercharging pressure limiting valve can be suppressed. When the boost pressure limiting valve is opened, the intake air in the intake collector flows out, and the amount of intake air flowing from the intake collector to each cylinder of the engine decreases. In the present invention, since the opening operation of the supercharging pressure limiting valve is suppressed as described above, a decrease in the intake air flow flowing to each cylinder can be suppressed, and as a result, a decrease in engine output such as acceleration performance can be prevented. An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view showing an embodiment of an intake collector device for a supercharged engine according to the present invention, together with a part of the engine. An intake port 13 and an exhaust port 14 are opened in the combustion chamber 12 of each cylinder of the multi-cylinder racing engine 11, and these ports 13 and 14 are opened and closed by an intake valve 15 and an exhaust valve 16, respectively.
The intake port 13 communicates with an intake passage 17, and the exhaust port 14 communicates with an exhaust passage 18. The racing engine 11 is a supercharged engine provided with an exhaust turbocharger 19 as a supercharger. Exhaust gas B is supplied to the exhaust turbocharger 19 via an exhaust manifold 20 connected to an exhaust passage 18. Be guided. The exhaust B rotates a turbine (not shown) of the exhaust turbocharger 19 at high speed, whereby the compressor of the exhaust turbocharger 19 rotates at high speed to pressurize the intake air A. It is supplied into the intake collector 22. The intake collector 22 is formed by integrating a collector housing 23 with a number of funnels 24 corresponding to the number of cylinders of the multi-cylinder racing engine 11 (the number of combustion chambers 12). These funnels 2
An inlet manifold 25 is fixed to each of the cylinders 4, and these inlet manifolds 25 are connected to the intake passage 17 of the multi-cylinder racing engine 11. Accordingly, the intake air A taken into the intake collector 22 passes through the inlet manifold 25, and passes through the combustion chamber 12 in each cylinder of the multi-cylinder racing engine 11.
Distributed and supplied to A throttle valve 26 and a fuel tank 27 are installed in the inlet manifold 25.
Therefore, the intake air A taken into the intake collector 22 is
The flow rate flowing through the inlet manifold 25 is controlled according to the opening degree of the throttle valve 26. Fuel is injected from fuel injector 27 into intake air A flowing through inlet manifold 25. This injected fuel is mixed with the intake air A to form an air-fuel mixture. When the intake valve 15 is opened, the air-fuel mixture is introduced into the combustion chamber 12 of each cylinder of the multi-cylinder racing engine 11 through the intake passage 17. A boost pressure limiting valve 28 is installed in the collector housing 23 of the intake collector 22 by using a bolt 37 or the like. The boost pressure limiting valve 28 is connected to the intake collector 22 introduced by the exhaust turbocharger 19.
It controls the intake pressure (supercharging pressure) in the chamber to a fixed value (limit pressure) or less, and includes a valve body 29, a spring 30, and a valve casing 31. That is, the valve body 29 has a bottomed cylindrical shape, and the valve port 32 of the valve casing 31 can be closed by the urging force of the spring 30. When the intake pressure of the intake air A in the intake collector 22 reaches the above-described limit pressure, the valve body 29 opens the valve port 32 against the urging force of the spring 30, and the intake air in the intake collector 22 is released to the valve casing 31. The air is released from the hole 33 to the atmosphere, and the intake pressure in the intake collector 22 is controlled. The collector housing 23 of the intake collector 22 is constituted by connecting a main housing 34 and a sub-housing 35. The sub-housing 35 is provided downstream of the intake air A flowing through the intake collector 22. You. A diaphragm 36 as a pressure fluctuation reducing mechanism is sandwiched between the main housing 34 and the sub-housing 35. Therefore, the volume of the intake collector 22 is determined by being surrounded by the main housing 34 and the diaphragm 36. When the supercharging pressure of the intake air A introduced by the exhaust turbocharger 19 fluctuates due to pulsation, the diaphragm 36 bends in the α direction in FIG. 1 to change the volume of the intake collector 22. As a result, the intake collector 22
The pressure fluctuation in the intake air is reduced and becomes substantially constant, and the pressure in the intake collector 22 can be controlled to be equal to or lower than the limit pressure. Generally, when the supercharging pressure limiting valve 28 is opened, the intake air A in the intake collector 22 flows out to the atmosphere, and the intake air flow supplied from the intake collector 22 to each combustion chamber 12 of the multi-cylinder engine 11 decreases. Would. However, in this embodiment, since the opening operation of the supercharging pressure limiting valve 28 is suppressed, a decrease in the flow rate of intake air guided from the intake collector 22 to each combustion chamber of the multi-cylinder engine 11 can be suppressed. Therefore, it is possible to prevent a decrease in engine output such as acceleration performance. Further, since the volume of the intake collector 22 is changed by the diaphragm 36 and the pressure fluctuation in the intake collector 22 is reduced to a substantially constant pressure, the combustion of the multi-cylinder engine 11 through the inlet manifold 25 is performed. The flow rate of the intake air flowing into the chamber becomes uniform, and the efficiency of inflow of the intake air A can be improved. Here, since the amount of fuel injected from the fuel injector 27 is the same in each of the inlet manifolds 25, the multi-cylinder engine 1
1, the air-fuel ratio of the mixture of the intake air A and the injected fuel flowing into each combustion chamber 12 becomes equal, the combustion balance of the multi-cylinder engine 11 is improved, and the output of the engine can be improved. FIG. 2 is a partial sectional view showing a part of another embodiment of the intake collector according to the present invention. In the other embodiments, the same parts as those in the first embodiment are denoted by the same reference numerals. In this embodiment, as a pressure fluctuation mitigation mechanism,
An air piston 38 is provided. The air piston 38 is slidably accommodated in the sub-housing 39 along the flow direction of the intake air A flowing through the intake collector 40. Main housing 34 and sub housing 3
9, the stroke ends 41 and 4 of the air piston 38
2 are each formed. Also, this air piston 38
An O-ring 43 is interposed on the outer periphery of the
Is always performed in an airtight state. Therefore, the volume of the intake collector 40 is determined by the main housing 34 and the air piston 38. In this embodiment, the exhaust turbocharger 1
The air piston 38 slides in the direction of the arrow β (the same direction as the α direction) due to the pressure fluctuation of the intake air A introduced from 9. Thereby, the volume of the intake collector 40 is changed,
The pressure fluctuation in the intake collector 40 is reduced. As a result, the valve opening operation of the supercharging pressure limiting valve 28 is suppressed,
A reduction in engine output is prevented, and the flow rate of intake air flowing from the intake collector 40 to each combustion chamber 12 of the multi-cylinder engine 11 is made uniform, so that engine output can be improved. As described above, according to the intake collector of the supercharged engine according to the present invention, the pressure fluctuation in the intake collector is alleviated and the opening operation of the supercharging pressure limiting valve is suppressed. Thus, it is possible to prevent the output of the engine from decreasing.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional view showing an embodiment of an intake collector device of a supercharged engine according to the present invention, together with a part of the engine. FIG. 2 is a partial sectional view showing a part of another embodiment of the present invention. FIG. 3 is a cross-sectional view showing a conventional intake collector device of a supercharged engine. [Description of Signs] 11 Multi-cylinder racing engine 12 Combustion chamber 19 Exhaust turbocharger 22 Intake collector 28 Supercharging pressure limiting valve 29 Valve element 31 Valve casing 32 Valve port 33 Relief hole 34 Main housing 35 Sub-housing 36 Diaphragm

Claims (1)

(57) [Claims 1] A supercharger which takes in intake air pressurized by a supercharger into an intake collector and distributes and supplies the intake air from the intake collector to each cylinder of the engine. In the intake collector device of the engine, a supercharging pressure limiting valve is installed in the intake collector so that the pressure in the intake collector is limited to a certain value or less, and the intake collector is connected to the intake collector. A pressure fluctuation reducing mechanism for reducing the pressure fluctuation in the intake collector by changing the volume of the intake collector.