JPH04276130A - Controller for internal combustion engine with turbo supercharger - Google Patents

Abstract

PURPOSE:To maintain a high exhaust efficiency in a high engine speed range by communicating the aggregate parts of respective exhaust branch tube groups through a communicating part, and providing a control valve which closes the opening part of the communicating part and the lead out part to one turbo supercharger alternately to generate high torque from a low engine speed range through a high engine speed range. CONSTITUTION:Exhaust branch tubes of cylinders whose exhaust air flow does not interfere with each other are aggregated in aggregate parts 12A, 12B on the downstream side respectively to divide them into two groups. Turbo superchargers 20A, 20B are equipped with the respective exhaust branch tube groups through lead out passages 13A. 13B respectively. The turbo superchargers 20A, 20B are constituted so that their driving may be controlled selectively according to the driving condition of the internal combustion engine. The aggregate parts 12A, 12B of the respective exhaust branch tube groups are communicated through a communicating part 12C. There is provided a control valve 15 which closes the opening of the communicating part 12C and the lead out passage 13B alternately to the turbo supercharger 20B.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control system for a turbocharged internal combustion engine of an automobile or the like.

0002

[Prior Art] Conventionally, in order to improve the performance of internal combustion engines in automobiles, etc., exhaust gas turbines are used to rotate a turbine using the energy of exhaust gas, and a compressor directly connected to the turbine compresses intake air and sends it to the internal combustion engine. feeding machine is used.

[0003] This type of turbocharger operates with high efficiency in a relatively high speed range, but cannot sufficiently improve torque in a low speed range, and also operates with high efficiency in a relatively low speed range. However, those that do tend to be unable to sufficiently improve output in the high-speed range.

[0004] For this reason, conventionally known engines are equipped with two turbo superchargers to improve performance over the entire range.

FIG. 4 is a schematic diagram showing an example of such an internal combustion engine with two turbochargers.

As shown in FIG. 4, the exhaust branch pipes 52a to 52f of each cylinder of the engine 51 are grouped together by collecting portions 53A and 55B, where the exhaust flow does not interfere with each other. The exhaust flow is configured to be guided to turbochargers 55A and 55B, respectively. In addition,
Reference numeral 57 is an exhaust pipe, and 58 is an intake pipe for feeding compressed air.

However, even in such a configuration, there has been a demand for further performance improvement in the low speed region and high speed region. To deal with this, a method is known in which two turbochargers are selectively activated depending on the operating state of the engine.

FIG. 5 shows an example of a control device for such a turbocharged internal combustion engine. In FIG. 5, the exhaust branch pipes 52a to 52f are gathered together by a gathering part 53, and are connected to turbochargers 55A and 55B via parallel outlet passages 54A and 54B, with one outlet passage being 54B is provided with a control valve 56 that opens and closes the conduit. By opening and closing this control valve 56, the entire exhaust flow is guided only to the turbocharger 55A in the low speed range, and the exhaust flow is guided to the turbochargers 55A and 55B in the high speed range. (Note that known technologies for such turbocharger control devices include those described in, for example, Utility Model Application No. 56-161134, Utility Model Publication No. 60-38027, etc.)

[0009]

[Problems to be Solved by the Invention] However, although such a conventional control device for a turbocharged internal combustion engine generates high torque from a low speed range to a high speed range, the exhaust flow decreases in the high speed range. There was a problem in that the pumps interfere with each other and the exhaust efficiency decreases.

This invention was made to solve the above problem, and its purpose is to generate high torque from low speed range to high speed range, and to maintain high exhaust efficiency in the high speed range. The present invention aims to provide a control device for an internal combustion engine equipped with a turbo supercharger.

[0011]

[Means for Solving the Problems] This invention has been made to achieve the above object, and the exhaust branch pipes of the cylinders whose exhaust flows do not interfere with each other are collected at a downstream collecting part. The exhaust branch pipes are combined into two groups, and each exhaust branch pipe group is equipped with a turbo supercharger through a lead-out passage. A control device for an internal combustion engine with a charger, wherein the gathering portions of the exhaust branch pipe groups are communicated with each other by a communication portion, and the control device is capable of alternately closing the opening of the communication portion and the lead-out path to one turbo supercharger. This is a control device for an internal combustion engine equipped with a turbocharger, characterized in that a valve is provided.

0012

[Operation] This invention is constructed as described above, and by switching the control valve according to the operating state of the internal combustion engine, two turbo superchargers can be selectively operated and the interference of exhaust flow can be avoided. operate without it.

That is, in a low speed region, the control valve closes the exhaust gas outlet path to one turbocharger. As a result, the gathering portions of the exhaust branch pipe groups of the internal combustion engine communicate through the communication portions, and the entire exhaust flow of each cylinder is guided only to the other turbocharger. The turbine is then rotated at high speed to compress intake air and supply it to the internal combustion engine, generating high torque.

[0014] In the high speed region, the control valve closes the communication portion opening and blocks the gathering portions of each exhaust branch pipe group. Further, one outlet path is open, and each exhaust branch pipe group communicates with each turbo supercharger via the outlet path from the respective collecting portion.

[0015] Exhaust flows from the exhaust branch pipes of the cylinders that do not interfere with each other are guided to the turbochargers without exhaust interference with each other, thereby driving each turbocharger with high exhaust efficiency.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic diagram of a control system for a turbocharged internal combustion engine according to an embodiment of the present invention.

In FIG. 1, 1 is a multi-cylinder engine, and an exhaust manifold 10 is attached to exhaust ports of cylinders 2a to 2f of the engine 1.

In the embodiment, the exhaust manifold 10 is connected to cylinder 2.
Exhaust branch pipes 11a to 11f respectively corresponding to a to 2f, collecting parts 12A, 12B and communication part 12C that divide them into two and converge them, and exhaust flow to turbo superchargers 20A, 20.
It is integrally formed with lead-out paths 13A and 13B leading to B.

Exhaust branch pipes 11a to 1 of exhaust manifold 10
1f is divided into two groups in which the intake strokes of the cylinders 2a to 2f are not continuous with each other, that is, the exhaust flows do not interfere with each other. For example, the exhaust branch pipes are grouped into an exhaust branch pipe group consisting of exhaust branch pipes 11a to 11c corresponding to the cylinders 2a to 2c, and an exhaust branch pipe group consisting of exhaust branch pipes 11d to 11f corresponding to the cylinders 2d to 2f. Exhaust branch pipe 11a~
The downstream side of the exhaust branch pipes 11c is collected by a collection part 12A, and the downstream side of the exhaust branch pipes 11d to 11f is collected by a collection part 12B. The gathering portions 12A and 12B are the communication portions 12A and 12B.
They are connected to each other by C.

[0021] The consolidating parts 12A and 12B are provided with lead-out passages 14A and 14B at predetermined positions, respectively. Further, a control valve 15 for switching the direction of the exhaust flow is disposed near the opening of the outlet path 13B of the gathering portion 12B and near the communication portion 12C.

When the control valve 15 is switched to one side, it closes the opening of the outlet passage 13B and allows communication between the gathering part 12B and the communicating part 12C, and when it is switched to the other side, it closes the opening of the outlet passage 13B and allows communication between the collecting part 12B and the communicating part 12C. and closing the gap between the gathering part 12B and the lead-out path 13.
It is configured to communicate with B.

A turbine 21A of a turbocharger 20A is connected to the downstream end of the outlet passage 13A, and a turbine 21A of the turbocharger 20B is connected to a downstream end of the outlet passage 13B.
1B is connected. And each turbine 21A, 21
The exhaust outlets of B are connected to exhaust pipes 25, respectively. Also, the compressor 22A of the turbo supercharger 20A, 20B
, 22B are connected to an intake pipe 33 via air guide pipes 30A and 30B, respectively, and the intake pipe 33 is connected to intake ports of the cylinders 2a to 2f via a throttle body 35 and an intake manifold 36. There is.

The control valve 15 is controlled by an actuator and a control device (not shown) to control the rotational speed of the engine 1,
It is configured to be driven and controlled according to load, intake pressure, etc.

Next, the operation of the control system for a turbocharged internal combustion engine constructed as described above will be explained.

When the engine 1 is operating at low speed, the control valve 15
As shown in FIG.
A communication state is established via 2C.

The intake air from the air cleaner (not shown) is compressed by the compressors 22A and 22B of the turbochargers 20A and 20B, and then passed through the air guide pipes 30A and 30.
B and the intake pipe 33 via the throttle body 35, and from the intake manifold 36 to each cylinder 2a to 2 of the engine 1.
f.

Further, the exhaust gas from the cylinders 2a to 2c is led to the outlet passage 13A via the exhaust branch pipes 11a to 11c and the collecting part 12A, and the exhaust gas from the cylinders 2d to 2f is led to the exhaust pipe 11d to 11f, respectively. Then, it is led to the lead-out path 13A via the collecting part 12B, the communicating part 12C, and the collecting part 12A.

Therefore, all the exhaust gas from each cylinder 2a to 2f is supplied to the turbine 21A of the turbocharger 20A, and is discharged by driving the turbine 21A. At this time, the lead-out path 13
B is in a fully closed state, and no exhaust gas is supplied to the turbocharger 20B.

In this way, the switching valve 15 allows the outlet passage 13 to
By closing the B opening and communicating the gathering parts 12A and 12B, all the exhaust from the exhaust branch pipes 11a to 11f can be supplied only to the turbocharger 20A. Therefore, even if the amount of exhaust gas is small due to low speed operation, the turbine 21A is driven at high rotation speed and the compressor 22A is
increases the pressure of intake air and supplies it to each cylinder 2a to 2f, allowing the engine 1 to generate high torque.

On the other hand, when the engine 1 is operating at high speed, the control valve 15 closes the opening of the communication portion 12C as shown in FIG.
The connection between the gathering parts 12A and 12B is cut off, and the opening of the outlet path 13B is opened.

That is, the lead-out passages 13A and 13B connected to the turbochargers 20A and 20B, respectively, are fully opened. The exhaust flow of the exhaust branch pipes 11a to 11c is then
2A to the outlet path 13A, supplied to the turbine supercharger 20A, drives the turbine 21A, and is discharged. Further, the exhaust flow from the exhaust branch pipes 11d to 11f is guided to the outlet path 13B via the gathering portion 12B, supplied to the turbocharger 20B, drives the turbine 21B, and is discharged.

At this time, the communication portion 12C is completely closed, and the exhaust flow from the exhaust branch pipes 11a to 11c and the exhaust branch pipes 11d to
The exhaust flows of 11f are guided to the turbo superchargers 20A and 20B without interfering with each other, thereby preventing energy loss due to exhaust interference and driving the turbo superchargers 20A and 20B with high exhaust efficiency.

It should be noted that the present invention is not limited to the above description and illustrated examples, and the embodiments thereof can be modified without departing from the technical idea of the present invention. For example, a control valve may be provided in each of the communication portion and one of the outlet paths, and the control valves may be configured to be linked and alternately opened and closed. According to this configuration, the arrangement position of one of the lead-out paths can be freely set.

[0035]

[Effects of the Invention] As explained above, the control device for an internal combustion engine with a turbo supercharger of the present invention collects the exhaust branch pipes of the cylinders whose exhaust flows do not interfere with each other at the collecting part on the downstream side. The exhaust branch pipes are grouped into two groups, and each exhaust branch pipe group is equipped with a turbocharger via a lead-out path, allowing the turbocharger to be selectively driven and controlled according to the operating status of the internal combustion engine. A control device for an engine-equipped internal combustion engine, wherein the collecting parts of each exhaust branch pipe group are communicated with each other by a communication part, and a control valve is provided that can alternately close an opening of the communication part and a lead-out path to one turbo supercharger. Because of this configuration, in the low-speed range, the entire exhaust flow from each cylinder is directed to only one turbocharger, so even if the amount of exhaust gas is small in low-speed operation, that turbocharger can be driven at high rotation speeds. It is possible to increase the intake air pressure of the internal combustion engine and generate high torque.

In addition, in the high-speed region, the exhaust flows from the exhaust branch pipe groups that do not interfere with each other are directly connected to the turbo supercharger and guided to each other, preventing exhaust interference and increasing the The exhaust efficiency can drive the turbo supercharger.

Therefore, according to the control device of the present invention, the turbocharger can be efficiently driven from a low speed region to a high speed region to generate high torque.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of a control device for a turbocharged internal combustion engine according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing the flow of exhaust gas in the exhaust manifold when the exhaust manifold is similarly operated in a low speed region.

FIG. 3 is an explanatory diagram showing the flow of exhaust gas in the exhaust manifold when the exhaust manifold is similarly operated in a high-speed region.

FIG. 4 is a schematic diagram showing a conventional example of an internal combustion engine with two turbochargers.

FIG. 5 is a schematic diagram of a conventional control device for an internal combustion engine with a turbocharger.

[Explanation of symbols]

1 Engine 10 Exhaust manifold 11a-11f Exhaust branch pipe 12A, 12B Collection area 12C Communication part 13A, 13B Derivation path 15 Control valve 20A, 20B Turbo supercharger

Claims (1)

[Claims] Claim 1: Exhaust branch pipes of cylinders whose exhaust flows do not interfere with each other are assembled into two groups at a downstream gathering point, and a turbo filter is connected to each exhaust branch pipe group via a lead-out path. A control device for an internal combustion engine equipped with a turbo supercharger, which is equipped with a charger and can selectively drive and control the turbo supercharger according to the operating state of the internal combustion engine, the control device comprising: a collection of each of the exhaust branch pipe groups; 1. A control device for an internal combustion engine with a turbocharger, characterized in that the parts are communicated with each other by a communication part, and a control valve is provided which can alternately close an opening of the communication part and a lead-out path to one turbocharger.