EXHAUST PASSAGE STRUCTURE OF MULTI-CYLINDER ENGINE

• US 20100206265A1
• Filed: 01/22/2010
• Published: 08/19/2010
• Est. Priority Date: 02/13/2009
• Status: Active Grant

• Current Assignee: Mazda Motor Corporation
• Original Assignee: Mazda Motor Corporation
• Inventors: AOKI, Osamu, MASUYAMA, Susumu, YAMAGATA, Naoyuki
• Granted Patent: US 8,256,402 B2
• Time in Patent Office: Days
• US Class Current: 123/337
• CPC Class Codes: F01N 13/10 of exhaust manifolds with cooling jacket F01N3/046
• CPC Class Codes: F01N 2240/36 an exhaust flap
• CPC Class Codes: F02B 27/06 the systems having variable, i.e. adjustable, cross-sectional areas, chambers of variable volume, or like variable means
• CPC Class Codes: F02B 37/02 Gas passages between engine outlet and pump drive, e.g. reservoirs
• CPC Class Codes: F02B 37/22 by varying cross-section of exhaust passages or air passages , e.g. by throttling turbine inlets or outlets or by varying effective number of guide conduits F02B37/24 takes precedence
• CPC Class Codes: F02D 9/04 concerning exhaust conduits throttle valves, or arrangements thereof in conduits F02D9/08
• CPC Class Codes: Y02T 10/12 Improving ICE efficiencies

Abstract

Three or more independent passages are coupled to respective cylinders which are different from each other, and a collective portion where the independent passages collect is provided. An exhaust turbocharger is arranged downstream of the collective portion. Rotary throttle valves are arranged respectively in the independent passages upstream of the collective portion. At least two of the throttle valves are supported by a common rotary axis. The independent passages with the throttle valves supported by the common rotary axis are coupled to cylinders which have exhaust strokes which are not adjacent to each other. Accordingly, the exhaust gas can be supplied to the exhaust turbocharger efficiently.

Claims

1. An exhaust passage structure of a multi-cylinder engine which has a valve-overlapping term when an intake valve in an intake stroke and an exhaust valve in an exhaust stroke open together for a specified period of time, comprising:

three or more independent passages coupled to respective cylinders which are different from each other;

a collective portion where said independent passages collect;

an exhaust turbocharger arranged downstream of said collective portion;

rotary throttle valves arranged respectively in said independent passages upstream of said collective portion,

wherein at least two of said throttle valves are supported by a common rotary axis, and said independent passages in which said two of the throttle valves supported by the common rotary axis are arranged are coupled to cylinders which have exhaust strokes which are not adjacent to each other.

2. The exhaust passage structure of a multi-cylinder engine of claim 1, wherein said throttle valve is a butterfly valve.

3. The exhaust passage structure of a multi-cylinder engine of claim 2, wherein said plural independent passages are arranged so as to surround a substantial center of said collective portion.

4. The exhaust passage structure of a multi-cylinder engine of claim 3, wherein said multi-cylinder engine is an inline four-cylinder engine which has Nos. 1, 2, 3 and 4 cylinders arranged in an inline shape and the Nos. 2 and 3 cylinders positioned at a center portion of the engine have exhaust strokes thereof which are not adjacent to each other, said independent passages comprise a No. 1 independent passage connecting to an exhaust port of the No. 1 cylinder, a No. 2 independent passage connecting to respective exhaust ports of the Nos. 2 and 3 cylinders, and a No. 3 independent passage connecting to an exhaust port of the No. 4 cylinder, and the throttle valve arranged in said No. 1 independent passage and the throttle valve arranged in said No. 3 independent passage are supported by the common rotary axis.

5. The exhaust passage structure of a multi-cylinder engine of claim 3, wherein said multi-cylinder engine is an inline four-cylinder engine, said independent passages are four independent passages which are coupled respectively to four cylinders of the four-cylinder engine, downstream end portions of said four independent passages are arranged so as to surround a substantial center of said collective portion, specified two independent passages are arranged along a first rotary-axis line, the other two independent passages are arranged along a second rotary-axis line which is provided in parallel to the first rotary-axis line, and the throttle valves of said specified two independent passages have the common rotary axis and the throttle valves of said other two independent passages have another common rotary axis.

6. The exhaust passage structure of a multi-cylinder engine of claim 3, wherein said independent passages are formed in an exhaust manifold, a middle member is arranged between said exhaust manifold and said exhaust turbocharger, said collective portion and respective downstream portions of the independent passages are formed in said middle member, an actuator to drive said rotary axes of the throttle valves is provided, and said downstream portions of the independent passages formed in the middle member are arranged in parallel to each other.