JPH01208519A - Multiple cylinder internal combustion engine with turbocharger - Google Patents

Abstract

PURPOSE:To aim at a marked improvement in low speed torque in an engine in which two cylinder lines are provided with their respective turbochargers by connecting two exhaust pipes which are led to the turbine parts of the respective turbochargers via a bypass pipe of which an intermediate part is connected to the outlet-side exhaust pipe of a turbine part. CONSTITUTION:An intake manifold 1 connected to respective intake part of the right and left cylinder lines Cr, Ce of V type multiple cylinder engine is connected to a throttle body 3 having a throttle valve 2, and the first and the second intake pipes 4, 5 connected to said body 3 are connected to the outlets of the compressor portions 6a, 8a of the first and the second turbochargers 6, 7 respectively. Right and left the first and the second exhaust pipes 9, 10 connected to respective exhaust port of right and left cylinder lines Cr, Ce are connected to the inlets of intake turbine portions 6b, 8b of respective turbocharger 6, 8 and the outlets of the turbine portions 6b, 8b are connected to a common main catalytic converter 13. The first and the second exhaust pipes 9, 10 are connected via a bypass 16 and its intermediate part is connected to an exhaust pipe via a waste gate valve 19.

Description

Detailed Description of the Invention A1 Object of the Invention (1) Industrial Application Field The present invention relates to a multi-cylinder internal combustion engine with a supercharger, particularly a multi-cylinder internal combustion engine equipped with two superchargers to improve torque. Concerning internal combustion engines.

(2) Prior Art Conventionally, a multi-cylinder internal combustion engine equipped with two superchargers is known, for example, from Japanese Patent Publication No. 54-27485.

(3) Problems to be Solved by the Invention However, in the conventional engine mentioned above, two superchargers are used even in the low speed range of the internal combustion engine, so the amount of exhaust gas per supercharger is small in the low speed range. The boost pressure rises slowly. Therefore, it is not expected that there will be much improvement in low-speed torque compared to a system equipped with a single supercharger. In addition, in the low speed range, the exhaust gas has less energy, so the catalyst is difficult to activate and the amount of harmful components in the exhaust gas may increase.

The present invention has been made in view of the above circumstances, and is a supercharger-equipped multi-function device that accelerates the build-up of supercharging pressure, significantly improves low-speed torque, and makes it possible to reduce harmful components in exhaust gas in the low-speed range. The purpose is to provide a cylinder internal combustion engine.

B0 Configuration of the Invention (+) Means for Solving the Problems According to the present invention, an intake manifold connected to a plurality of cylinders is provided with an intake compressor section outlet of a first supercharger having a variable capacity and another second supercharger. A first exhaust pipe leading to a specific cylinder of the plurality of cylinders is connected to an inlet of an exhaust turbine section of the first supercharger, and a first exhaust pipe leading to a specific cylinder among the plurality of cylinders is connected to the intake air compressor section outlet of the charger. A second exhaust pipe leading to the cylinder is connected to an inlet of the exhaust turbine part of the second supercharger, an outlet of the exhaust turbine part of the first and second superchargers is commonly connected to the main catalytic converter, The intermediate portions of the two exhaust pipes are connected via a detour pipe provided with a sub-catalytic converter, and the connection between the sub-catalytic converter and the second exhaust pipe of the detour pipe and between the main catalytic converter and the exits of both exhaust turbine parts can be opened or closed. Connected via possible wastegate valve.

(2) Effect According to the above configuration, the capacity of the first supercharger is minimized in the low speed range of the engine, and the waste gate valve is closed, so that the exhaust gas flowing through the first exhaust pipe is passed through the bypass pipe to the second supercharger. By increasing the amount of exhaust gas flowing into the supercharger and into the second supercharger, the rise in supercharging pressure can be accelerated. In addition, the sub-catalytic converter provided in the middle of the detour pipe is close to the exhaust outlet of the engine, so that the exhaust gas can flow through the converter before the temperature drops significantly, activating the catalyst and reducing harmful components. Furthermore, when the supercharging pressure exceeds a predetermined value, the capacity of the first supercharger is increased to reduce the amount of exhaust gas flowing through the bypass pipe, but after the capacity of the first supercharger reaches its maximum, The boost pressure can be controlled by a wastegate valve.

(3) Embodiment Hereinafter, an embodiment of the present invention will be described with reference to the drawings.The engine main body E has, for example, a right cylinder row Cr in which three cylinders are arranged in parallel, and a left cylinder row in which three cylinders are arranged in parallel. C! It is configured as a type 6 cylinder, with both cylinder rows Cr,
C1! A throttle body 3 having a throttle valve 2 is connected to an intake manifold 1 connected to each intake port. A first intake pipe 4 and a second intake pipe 5 are commonly connected to the throttle body 3, and the first intake pipe 4 is connected to the outlet of the air supply compressor section 6a of the first supercharger 6 whose capacity is variable. The inlet of the supply air compressor section 6a is connected to the air cleaner 7.

Further, the second intake pipe 5 is connected to the outlet of the supply air compressor section 8a in the second supercharger 8, and the second intake pipe 5 is connected to the outlet of the supply air compressor section 8a in the second supercharger 8.
The inlet of a is connected to an air cleaner 7.

On the other hand, a first exhaust pipe 9 is commonly connected to the exhaust port of each cylinder in the right cylinder row Cr, and this first exhaust pipe 9 is connected to the inlet of the exhaust turbine section 6b of the first supercharger 6, A second exhaust pipe 10 is commonly connected to the exhaust port of each cylinder in the left cylinder row CIl, and this second exhaust pipe IO is connected to the inlet of the exhaust turbine section 8b of the second supercharger 8. Further, the outlet of the exhaust turbine section 6b in the first supercharger 6 is connected to the main catalytic converter 13 via the third exhaust pipe 11, and the outlet of the exhaust turbine section 8b in the second supercharger 8 is connected to the fourth exhaust pipe 12. It is connected to the main catalytic converter 13 via.

The exhaust turbine section 6b of the first supercharger 6 is provided with a movable vane 14 whose capacity can be varied.The movable vane 14 is driven by an actuator 15. By rotating the movable vane 14,
The amount of exhaust gas introduced into the exhaust turbine section 6b is controlled.

A detour pipe 16 is branched from the first exhaust pipe 9 close to the exhaust port of each cylinder in the right cylinder row Cr, and this detour pipe 16 is connected to the middle of the second exhaust pipe IO. Furthermore, an auxiliary catalytic converter 17 is interposed in the intermediate portion of the detour pipe 16 closer to the first exhaust pipe 9. Furthermore, the detour pipe 16 between the auxiliary catalytic converter 17 and the second exhaust pipe 10 and the main catalytic converter 13 and the exhaust turbine parts 6b and 8b of both the superchargers 6 and 8, for example the fourth exhaust pipe 12, are connected by the actuator 18. Wastegate valve 1 driven to open and close
9.

Next, the operation of this embodiment will be explained. In the low speed operating range of the engine, the movable vane 14 of the first supercharger 6 is driven to minimize the capacity, and the wastegate valve 19 is kept closed.

In this case, the exhaust gas discharged from the right cylinder row Cr is not introduced into the first supercharger 6, but passes through the detour pipe 16 and exits from the second exhaust pipe 10 together with the exhaust gas discharged from the left cylinder row Cl. 2 is introduced into the exhaust turbine section 8b of the supercharger 8. Therefore, in the exhaust turbine section 8b of the second supercharger 8, both cylinder rows Cr, Cm! Since all the exhaust gas from the engine is led to the exhaust turbine section 8b, the amount of exhaust gas to the exhaust turbine section 8b is relatively large, and the boost pressure can be increased quickly and low-speed torque can be significantly improved.

Furthermore, in the main catalytic converter 13, since the energy contained in the exhaust gas is relatively small, it is difficult to activate the catalyst. Since it flows, it is introduced into the secondary catalytic converter 17 in a relatively high temperature state, thereby promoting activation of the catalyst in the secondary catalytic converter 17, removing harmful components, and supplying it to the second supercharger 8. Therefore, it is possible to reduce harmful components in the exhaust gas as a whole.

When the supercharging pressure reaches a certain value or more, the movable vane 14 of the first supercharger 6 is driven in the direction of increasing the capacity, and the capacity of the first supercharger 6 is increased while controlling the supercharging pressure. Maximize. At this time, as the capacity of the first supercharger 6 increases, the amount of exhaust gas flowing from the first exhaust pipe 9 to the detour pipe 16 decreases (.

After the capacity of the first supercharger 6 reaches its maximum, the supercharging pressure can be controlled by controlling the opening degree of the wastegate valve 19.

In the above embodiment, a 6-cylinder internal combustion engine was explained.
The present invention is also applicable to multi-cylinder internal combustion engines other than six cylinders.

Effects of the C0 Invention As described above, according to the present invention, the intake manifold connected to a plurality of cylinders has a variable capacity intake air compressor section outlet of the first supercharger and another intake air compressor of the second supercharger. A first exhaust pipe that communicates with a specific cylinder among the plurality of cylinders is connected to an inlet of the exhaust turbine section of the first supercharger, and a second exhaust pipe that communicates with the remaining cylinders excluding the specific cylinder. An exhaust pipe is connected to the exhaust turbine part inlet of the second supercharger, the exhaust turbine part outlets of the first and second superchargers are commonly connected to the main catalytic converter, and an intermediate part of the first and second exhaust pipes is connected to the exhaust turbine part inlet of the second supercharger. A waste gate valve that can be opened and closed is connected between the secondary catalytic converter and the second exhaust pipe of the detour pipe, and between the main catalytic converter and the exits of both exhaust turbine parts. Since the capacity of the first turbocharger is minimized in the low speed range of the engine, and the waste gate valve is closed, the amount of exhaust gas flowing into the second turbocharger is increased to increase the boost pressure. It can accelerate startup and improve low-speed torque.

Furthermore, by allowing exhaust gas to flow through the sub-catalytic converter before the temperature drops significantly, the catalyst can be activated and harmful components can be reduced in the low-speed range. Further, when the supercharging pressure exceeds a predetermined value, the supercharging pressure can be controlled by the wastegate valve.

[Brief explanation of the drawing]

The drawing is an overall system diagram of an embodiment of the present invention. l...Intake manifold, 6...First supercharger, 6a
. 8a... Air supply compressor section, 6b, 8b... Exhaust turbine section, 8... Second supercharger, 9... First exhaust pipe, 10... Second exhaust pipe, 13...・Main catalytic converter, 16...Detour pipe, 17...Sub-catalytic converter, 1
9...Wastegate valve

Claims (1)

[Claims] An intake manifold connected to a plurality of cylinders is connected in common with an intake compressor section outlet of a first supercharger whose capacity is variable and an intake compressor section outlet of another second supercharger, and among the plurality of cylinders. A first exhaust pipe leading to the specific cylinder is connected to the exhaust turbine part inlet of the first supercharger, and a second exhaust pipe leading to the remaining cylinders excluding the specific cylinder is connected to the exhaust turbine part inlet of the second supercharger. the exhaust turbine section outlets of the first and second superchargers are commonly connected to the main catalytic converter, and the intermediate portions of the first and second exhaust pipes are connected via a detour pipe provided with a sub-catalytic converter. , wherein the secondary catalytic converter and the second exhaust pipe of the detour pipe are connected to the main catalytic converter and the outlet of both exhaust turbine parts via a waste gate valve that can be opened and closed. Multi-cylinder internal combustion engine.