INTERNAL COMBUSTION ENGINE, VEHICLE HAVING THE SAME, AND METHOD FOR MANUFACTURING INTERNAL COMBUSTION ENGINE

• US 20170175670A1
• Filed: 12/15/2016
• Published: 06/22/2017
• Est. Priority Date: 12/17/2015
• Status: Abandoned Application

• Current Assignee: Yamaha Hatsudoki Kabushiki Kaisha (Yamaha Corporation)
• Original Assignee: Yamaha Hatsudoki Kabushiki Kaisha (Yamaha Corporation)
• Inventors: NISHIMURA, Wataru
• Application Number:
  US15/379,525
• Publication Number:
  US 20170175670A1
• Time in Patent Office: Days
• CPC Class Codes: B23B 2215/24 Components of internal combustion engines B23B2215/16 and B23B2215/20 take precedence
• CPC Class Codes: B23B 41/12 for forming working surfaces of cylinders, of bearings, e.g. in heads of driving rods, or of other engine parts
• CPC Class Codes: F01L 2001/0537 Double overhead camshafts [DOHC]
• CPC Class Codes: F01L 2820/01 Absolute values
• CPC Class Codes: F01L 3/06 Valve members or valve-seats with means for guiding or deflecting the medium controlled thereby, e.g. producing a rotary motion of the drawn-in cylinder charge for rotating lift-valves F01L1/32
• CPC Class Codes: F02B 31/02 in engines having inlet valves arranged eccentrically to cylinder axis
• CPC Class Codes: F02B 61/02 for driving cycles
• CPC Class Codes: F02F 1/4235 of intake channels
• CPC Class Codes: F02F 2200/00 Manufacturing
• CPC Class Codes: F02M 35/10091 characterised by details of intake ducts: shapes; connections; arrangements ducts within or on the plenum chamber F02M35/10039
• CPC Class Codes: F02M 35/10209 Fluid connections to the air intake system; their arrangement of pipes, valves or the like
• CPC Class Codes: F02M 35/10367 Machining, e.g. milling, grinding, punching, sanding; Bending; Surface treatments
• CPC Class Codes: Y02T 10/12 Improving ICE efficiencies

Abstract

In an internal combustion engine, an angle defined by an axis of a boundary of an intake port adjoining a valve seat and a cylinder axis is greater than an angle defined by the axis of the valve seat and the cylinder axis. A step between a first inner wall and a second inner wall, the first inner wall being a portion of an inner wall of the valve seat that is closest to the cylinder axis and the second inner wall being a portion of an inner wall of the boundary of the intake port that is closest to the cylinder axis. The first inner wall is located on the outer side in the radial direction of the intake port than the second inner wall.

Claims

1. An internal combustion engine comprising:

a cylinder body defining a cylinder therein;

a cylinder head fixed on the cylinder body;

an intake port in the cylinder head, a downstream end of the intake port including an opening that faces the cylinder; and

a valve seat in the downstream end of the intake port;

wherein

along a cross section including an axis of the cylinder and an axis of the valve seat, an angle defined by an axis of a boundary of the intake port adjoining the valve seat and the axis of the cylinder is greater than an angle defined by the axis of the valve seat and the axis of the cylinder; and

a step is provided along the cross section between a first inner wall and a second inner wall, the first inner wall being a portion of an inner wall of the valve seat that is closest to the axis of the cylinder and the second inner wall being a portion of an inner wall of the boundary of the intake port that is closest to the axis of the cylinder, and the first inner wall is located on an outer side in a radial direction of the intake port with respect to the second inner wall.

2. The internal combustion engine according to claim 1, wherein a step is provided between a first half of the inner wall and a second half of the inner wall, the first half of the inner wall being a half of the inner wall of the valve seat that is closest to the axis of the cylinder and the second half of the inner wall being a half of the inner wall of the boundary of the intake port that is closest to the axis of the cylinder;

and

the first half of the inner wall is located on the outer side in the radial direction of the intake port with respect to the second half of the inner wall.

3. The internal combustion engine according to claim 1, wherein a step is provided between an entire length of the inner wall of the valve seat and an entire length of the inner wall of the boundary of the intake port;

and

the inner wall of the valve seat is located on the outer side in the radial direction of the intake port with respect to the inner wall of the boundary of the intake port.

4. The internal combustion engine according to claim 1, wherein a step is provided along the cross section between a third inner wall and a fourth inner wall, the third inner wall being a portion of the inner wall of the valve seat that is farther away from the axis of the cylinder than the first inner wall and the fourth inner wall being a portion of the inner wall of the boundary of the intake port that is farther away from the axis of the cylinder than the second inner wall, and the third inner wall is located on the outer side in the radial direction of the intake port with respect to the fourth inner wall;

and

the step between the first inner wall and the second inner wall is larger than the step between the third inner wall and the fourth inner wall.

5. The internal combustion engine according to claim 1, wherein the boundary of the intake port has an elliptical or substantially elliptical shape as seen from a direction of the axis of the valve seat.

6. A vehicle comprising the internal combustion engine according to claim 1.

7. A method for manufacturing an internal combustion engine, the method comprising the steps of:

inserting a throat cutter into a cylinder head provided with an intake port along a first axis from a downstream end of the intake port and machining an inner wall of the intake port with the throat cutter; and

inserting a valve seat into the downstream end of the intake port along a second axis, which defines an angle with respect to an axis of the cylinder along a cross section including the axis of the cylinder and the first axis that is smaller than an angle of the first axis with respect to the axis of the cylinder along the cross section;

wherein

in the step of inserting the valve seat, a step is provided at least along the cross section between a first inner wall and a second inner wall, the first inner wall being a portion of an inner wall of the valve seat that is closest to the axis of the cylinder and the second inner wall being a portion of an inner wall of a boundary of the intake port adjoining the valve seat that is closest to the axis of the cylinder, and the first inner wall is located on an outer side in a radial direction of the intake port with respect to the second inner wall.

8. The method for manufacturing an internal combustion engine according to claim 7, wherein, in the step of inserting the valve seat, a step is defined by a first half of the inner wall and a second half of the inner wall, the first half of the inner wall being a half of the inner wall of the valve seat that is closest to the axis of the cylinder and the second half of the inner wall being a half of the inner wall of the boundary of the intake port that is closest to the axis of the cylinder, and the first half is located on the outer side in the radial direction of the intake port with respect to the second half.

9. The method for manufacturing an internal combustion engine according to claim 7, wherein, in the step of inserting the valve seat, a step is defined by an entire length of the inner wall of the valve seat and an entire length of the inner wall of the boundary of the intake port, and the inner wall of the valve seat is located on the outer side in the radial direction of the intake port with respect to the inner wall of the boundary of the intake port.

10. The method for manufacturing an internal combustion engine according to claim 7, wherein

in the step of inserting the valve seat, a step is formed along the cross section between a third inner wall and a fourth inner wall, the third inner wall being a portion of the inner wall of the valve seat that is farther away from the axis of the cylinder than the first inner wall, the fourth inner wall being a portion of the inner wall of the boundary of the intake port that is farther away from the axis of the cylinder than the second inner wall, and the third inner wall is located on the outer side in the radial direction of the intake port with respect to the fourth inner wall;

and

the step between the first inner wall and the second inner wall is larger than the step between the third inner wall and the fourth inner wall.

11. The method for manufacturing an internal combustion engine according to claim 7, wherein the step of machining the inner wall of the intake port with the throat cutter is performed using a throat cutter having a diameter that is smaller than a valve head diameter of an intake valve provided in the intake port by about 4.5 mm or more.