Internal combustion engine with a dual turbocharger system

• US 5,186,005 A
• Filed: 03/07/1991
• Issued: 02/16/1993
• Est. Priority Date: 03/09/1990
• Status: Expired due to Fees

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Yoshioka, Mamoru, Sugiyama, Toshihisa, Kidokoro, Toru
• Primary Examiner(s): KOCZO JR, MICHAEL
• Application Number:
  US07/666,067
• Time in Patent Office: 712 Days
• Field of Search: 60/600, 60/612
• US Class Current: 60/600
• CPC Class Codes: F02B 37/007 with exhaust-driven pumps arranged in parallel , e.g. at least one pump supplying alternatively
• CPC Class Codes: Y02T 10/12 Improving ICE efficiencies

Abstract

An internal combustion engine with a dual turbocharger system which includes an engine, a first and a second turbocharger arranged in parallel with each other, an intake switching valve located downstream of a compressor of the second turbocharger, an exhaust switching valve located downstream of a turbine of the second turbocharger. The engine operation is changed between a "one-turbocharger-operation" wherein only the first turbocharger is operated and a "two-turbocharger-operation" wherein both the first turbocharger and the second turbocharger are operated. Change from the "one-turbocharger-operation" to the "two-turbocharger-operation" is performed on the basis of an intake air quantity, and change from the "two-turbocharger-operation" to the "one-turbocharger-operation" is performed on the basis of an engine speed. This type of change suppresses a torque shock at shift changing during acceleration and improves the drive feeling.

Claims

1. An internal combustion engine with a dual turbocharger system comprising:

a multi-cylinder internal combustion engine having an air intake and an exhaust outlet;

a first and a second turbocharger arranged in parallel with each other with respect to the engine, each including a turbine and a compressor, the turbine being connected with the exhaust outlet of the engine and the compressors being connected with the air intake of the engine;

an intake switching valve installed downstream of the second turbocharger compressor and an exhaust switching valve installed downstream of the second turbocharger turbine, means for opening the intake switching valve and the exhaust switching valve whereby both the first turbocharger and the second turbocharger operate to produce a "two-turbocharger-operation" and for closing the intake switching valve and the exhaust switching valve whereby only the first turbocharger operates to produce a "one-turbocharger-operation";

means for measuring an engine speed;

means for measuring an intake air quantity; and

decision means operatively connected with the intake air quantity measuring means, the engine speed measuring means, and the means for opening and closing the intake and exhaust switching valves and serving to change an engine operation from the "one-turbocharger-operation" to the "two-turbocharger-operation" on the basis of an intake air quantity and serving to change the engine operation from the "two-turbocharger-operation" to the "one-turbocharger-operation" on the basis of an engine speed.

2. An internal combustion engine with a dual turbocharger system according to claim 1, wherein the first decision means serves to open the intake switching valve and the exhaust switching valve whenever the intake air quantity changes from a quantity less than a predetermined intake air quantity to a quantity greater than the predetermined intake air quantity.

3. An internal combustion engine with a dual turbocharger system according to claim 2, wherein the predetermined intake air quantity is substantially 5,500 1/min.

4. An internal combustion engine with a dual turbocharger system according to claim 1, wherein the decision means serves to close the intake switching valve and the exhaust switching valve whenever the engine speed changes from a speed greater than a predetermined engine speed to a speed less than the predetermined engine speed.

5. An internal combustion engine with a dual turbocharger system according to claim 4, wherein the predetermined engine speed is substantially 3,000 rpm.

6. An internal combustion engine with a dual turbocharger comprising:

a multi-cylinder internal combustion engine with an air intake and at least one exhaust outlet, the engine including a first and a second group of cylinders;

an exhaust manifold connected with the engine exhaust outlet, the exhaust manifold including a first portion connected to the first group of the cylinders and a second portion connected to the second group of the cylinders, the first portion and the second portion of the exhaust manifold communicating with each other by a connecting conduit;

a first and a second turbocharger arranged in parallel with each other with respect to the engine, each including a turbine and a turbine driven compressor, the turbines being connected with the exhaust outlet of the engine by the exhaust manifold with the compressors being connected with the air intake of the engine;

an intake line including a first intake conduit connected with the first turbocharger compressor, a second intake conduit connected with the second turbocharger compressor, an intake connecting portion joining the first intake conduit and the second intake conduit, an intake common conduit connecting the intake connecting portion an the air intake of the engine;

an exhaust line including a first exhaust conduit connected with the first portion of the exhaust manifold, in which the first turbocharger turbine is installed, a second exhaust conduit connected with the second portion of the exhaust manifold, in which the second turbocharger turbine is installed, an exhaust connecting portion where the first exhaust conduit and the second exhaust conduit join each other, and an exhaust pipe located downstream of and connected with the exhaust connecting portion;

an intake switching valve installed downstream of the second turbocharger compressor in the second intake conduit and adapted to open and close the second intake conduit;

an exhaust switching valve installed downstream of the second turbocharger turbine in the second exhaust conduit and adapted to open and close the second exhaust conduit;

an exhaust bypass conduit connecting a portion of the second exhaust conduit downstream of the second turbocharger turbine and upstream of the exhaust switching valve with any one of a portion of the second exhaust conduit downstream of the exhaust switching valve, the exhaust connecting portion and a portion of the first exhaust conduit downstream of the first turbocharger turbine;

an exhaust bypass valve installed in the exhaust bypass conduit and adapted to open and close the exhaust bypass conduit;

means for measuring an engine speed;

means for measuring an intake air quantity; and

decision means operatively connected with the intake air quantity measuring means, the engine speed measuring means, the intake switching valve and the exhaust switching valve and serving to open the intake switching valve and the exhaust switching valve whenever the intake air quantity changes from a quantity less than predetermined intake air quantity to a quantity greater than the predetermined intake air quantity and serving to close the intake switching valve and the exhaust switching valve whenever the engine speed changes from a speed greater than a predetermined engine speed to a speed less than the predetermined engine speed.

7. An internal combustion engine with a dual turbocharger system according to claim 6, wherein the predetermined intake air quantity is substantially 5,500 1/min.

8. An internal combustion engine with a dual turbocharger system according to claim 6, wherein the predetermined engine speed is substantially 3,000 rpm.

9. An internal combustion engine with a dual turbocharger system comprising:

a multi-cylinder internal combustion engine having an air intake and an exhaust outlet;

a first and a second turbocharger arranged in parallel with each other with respect to the engine, each including a turbine and a compressor, the turbine being connected with the exhaust outlet of the engine and the compressors being connected with the air intake of the engine;

an intake switching valve installed downstream of the second turbocharger compressor and an exhaust switching valve installed downstream of the second turbocharger turbine, means for opening the intake switching valve and the exhaust switching valve whereby both the first turbocharger and the second turbocharger operate to produce a "two-turbocharger-operation" and for closing the intake switching valve and the exhaust switching valve whereby only the first turbocharger operates to produce a "one-turbocharger-operation";

means for measuring an engine speed;

means for measuring an intake air quantity;

decision means operatively connected with the intake air quantity measuring means, the engine speed measuring means and the means for opening and closing the intake and exhaust switching valves serving to change an engine operation from the "one-turbocharger-operation" to the "two-turbocharger-operation" on the basis of an intake air quantity, and serving to change the engine operation from the "two-turbocharger-operation" to the "one-turbocharger-operation" on the basis of an engine speed, the decision means further comprising delay means for delaying the change from the "two-turbocharger-operation" to the "one-turbocharger-operation" by a predetermined period of time.

10. An internal combustion engine with a dual turbocharger system according to claim 9, wherein the predetermined period of time is substantially 1 sec.

11. An internal combustion engine with a dual turbocharger comprising:

a multi-cylinder internal combustion engine with an air intake and at least one exhaust outlet, the engine including a first and second group of cylinders;

an exhaust manifold connected with the engine exhaust outlet, the exhaust manifold including a first portion connected to the first group of the cylinders and a second portion connected to the second group of the cylinders, the first portion and the second portion of the exhaust manifold communicating with each other by a connecting conduit;

a first and a second turbocharger arranged in parallel with each other with respect to the engine, each including a turbine and a turbine driven compressor, the turbines being connected with the exhaust outlet of the engine by the exhaust manifold with the compressors being connected with the air intake of the engine;

an intake line including a first intake conduit connected with the first turbocharger compressor, a second intake conduit connected with the second turbocharger compressor, an intake connecting portion joining the first intake conduit and the second intake conduit, an intake common conduit connecting the intake connecting portion an the air intake of the engine;

an exhaust line including a first exhaust conduit connected with the first portion of the exhaust manifold, in which the first turbocharger turbine is installed, a second exhaust conduit connected with the second portion of the exhaust manifold, in which the second turbocharger turbine is installed, an exhaust connecting portion where the first exhaust conduit and the second exhaust conduit join each other, and an exhaust pipe located downstream of and connected with the exhaust connecting portion;

an intake switching valve installed downstream of the second turbocharger compressor in the second intake conduit and adapted to open and close the second intake conduit;

an exhaust switching valve installed downstream of the second turbocharger turbine in the second exhaust conduit and adapted to open and close the second exhaust conduit;

an exhaust bypass conduit connecting a portion of the second exhaust conduit downstream of the second turbocharger turbine and upstream of the exhaust switching valve with any one of a portion of the second exhaust conduit downstream of the exhaust switching valve, the exhaust connecting portion and a portion of the first exhaust conduit downstream of the first turbocharger turbine;

an exhaust bypass valve installed in the exhaust bypass conduit and adapted to open and close the exhaust bypass conduit;

means for measuring an engine speed;

means for measuring an intake air quantity; and

decision means operatively connected with the intake air quantity measuring means, the engine speed measuring means, the intake switching valve and the exhaust switching valve and serving to open the intake switching valve and the exhaust switching valve whenever the intake air quantity changes from a quantity less than a predetermined intake air quantity to a quantity greater than the predetermined intake air quantity and serving to close the intake switching valve and the exhaust switching valve whenever the engine speed changes from a speed greater than a predetermined engine speed to a speed less than the predetermined engine speed, the decision means further comprising delay means for delaying the closing of the intake switching valve and the exhaust switching valve by a predetermined period of time.

12. An internal combustion engine with a dual turbocharger system according to claim 11, wherein the predetermined period of time is substantially 1 sec.