Multi-cylinder engine

Patent metadata

Field	Value
Publication number	US-11053894-B2
Application number	US-201916247781-A
Country	US
Kind code	B2
Filing date	Jan 15, 2019
Priority date	Jan 23, 2018
Publication date	Jul 6, 2021
Grant date	Jul 6, 2021

Abstract

A multi-cylinder engine includes an engine body having first and second cylinder groups, first and second exhaust passage groups each having a plurality of independent exhaust passage parts and a collective exhaust passage part, and an exhaust gas recirculation (EGR) passage. In a plan view in cylinder axis directions, the passage groups are disposed adjacent to each other, and, in the first exhaust passage group, a first independent exhaust part of the plurality of independent exhaust passage parts is connected to the EGR passage and a second independent exhaust passage part is connected to the collective exhaust passage part so as to be directed to a connection of the first independent exhaust passage part to the collective exhaust passage part, and in the second exhaust passage group, an opening of the collective exhaust passage part is offset toward the first exhaust passage group in a lineup direction.

First claim

What is claimed is:

1. A multi-cylinder engine, comprising:
an engine body having a first cylinder group comprised of a first plurality of cylinders disposed adjacent to each other, and a second cylinder group comprised of a second plurality of cylinders disposed adjacent to each other and provided adjacent to the first cylinder group;
a first exhaust passage group having a first plurality of independent exhaust passage parts connected to the first plurality of cylinders of the first cylinder group, respectively, and a first collective exhaust passage part collecting the first plurality of independent exhaust passage parts at downstream ends in an exhaust gas flow direction, and having an opening at the downstream side in the exhaust gas flow direction;
a second exhaust passage group having a second plurality of independent exhaust passage parts connected to the second plurality of cylinders of the second cylinder group, respectively, and a second collective exhaust passage part collecting the second plurality of independent exhaust passage parts at downstream ends in the exhaust gas flow direction, and having an opening at the downstream side in the exhaust gas flow direction; and
an exhaust gas recirculation (EGR) passage connected at one end to a first independent exhaust passage part of the first plurality of independent exhaust passage parts and connected at the other end to an intake passage,
wherein in a plan view of the first exhaust passage group and the second exhaust passage group in cylinder axis directions, the first exhaust passage group and the second exhaust passage group are disposed adjacent to each other,
wherein in the plan view, a second independent exhaust passage part and a third independent exhaust passage part of the first plurality of independent exhaust passage parts, different from the first independent exhaust passage part to which the EGR passage is connected, are connected to the first collective exhaust passage part so that a first directing axis of the first independent exhaust passage part, a second directing axis and a third directing axis of the second independent exhaust passage part, and a fourth directing axis and a fifth directing axis of the third independent exhaust passage part converge at the first collective exhaust passage part so as to be directed to a connection of the first independent exhaust passage part, the second independent exhaust passage part, and the third independent exhaust passage part to the first collective exhaust passage part,
wherein in the plan view, the opening of the second collective exhaust passage part is offset toward the first exhaust passage group in a lineup direction of the second plurality of independent exhaust passage parts,
wherein the engine body has a cylinder head,
wherein the first exhaust passage group having the first plurality of independent exhaust passage parts and the first collective exhaust passage part are formed in the cylinder head, and
wherein the second exhaust passage group having the second plurality of independent exhaust passage parts and the second collective exhaust passage part are formed in the cylinder head.

2. The multi-cylinder engine of claim 1 , wherein in the plan view, the opening of the first collective exhaust passage part is disposed closer to a center in a lineup direction of the first plurality of independent exhaust passage parts, compared with the opening of the second collective exhaust passage part.

3. The multi-cylinder engine of claim 1 , wherein fuel is injected alternately over time to the first cylinder group and the second cylinder group.

4. The multi-cylinder engine of claim 1 ,
wherein the first exhaust passage group and the second exhaust passage group are formed by exhaust ports of the cylinder head.

5. The multi-cylinder engine of claim 4 , further comprising an exhaust-pipe part having:
a first exhaust-pipe part connected to the first exhaust passage group in the cylinder head;
a second exhaust-pipe part connected to the second exhaust passage group in the cylinder head; and
a collective exhaust-pipe part collecting the first exhaust-pipe part and the second exhaust-pipe part at downstream ends in the exhaust gas flow direction.

6. The multi-cylinder engine of claim 5 , wherein the collective exhaust-pipe part is connected at a downstream end in the exhaust gas flow direction to a turbocharger.

7. The multi-cylinder engine of claim 6 , wherein the second exhaust-pipe part is formed so that a central path thereof extending to the collective exhaust-pipe part is more linear than a central path of the first exhaust-pipe part.

8. The multi-cylinder engine of claim 1 , wherein in the plan view, the first independent exhaust passage part is disposed farther from the second exhaust passage group, and the second independent exhaust passage part is disposed closer to the second exhaust passage group.

9. The multi-cylinder engine of claim 1 , wherein the opening of the second collective exhaust passage part is connected to a casing passage of a turbocharger.

10. The multi-cylinder engine of claim 1 ,
wherein the engine has six cylinders,
wherein the first cylinder group comprises three cylinders, and
wherein the second cylinder group comprises three cylinders.

11. The multi-cylinder engine of claim 7 , wherein the central path of the first exhaust-pipe part and the central path of the second exhaust-pipe part are formed in the turbocharger.

Assignees

• Mazda Motor

Inventors

• Uehane Yoshiyuki
• Ishimoto Daijirou
• Hatabu Atsuhiro

Classifications

• F02F2001/4278

  Exhaust collectors · CPC title

• F02F1/4264

  of exhaust channels · CPC title

• F02M26/43

  in which exhaust from only one cylinder or only a group of cylinders is directed to the intake of the engine · CPC title

• F02F1/243

  Cylinder heads and inlet or exhaust manifolds integrally cast together · CPC title

• F02B75/20

  with cylinders all in one line · CPC title