Intake structure for internal combustion engine

Patent metadata

Field	Value
Publication number	US-9611820-B2
Application number	US-201514662135-A
Country	US
Kind code	B2
Filing date	Mar 18, 2015
Priority date	Apr 3, 2014
Publication date	Apr 4, 2017
Grant date	Apr 4, 2017

Abstract

The intake structure for an internal combustion engine includes: a collision surface configured to face an inlet of a carburetor; a deflecting surface configured to deflect a blowback flow, which is to diffuse after colliding against the collision surface, in one direction along the collision surface; a receiving surface configured to receive the blowback flow deflected by the deflecting surface; and a fuel-accumulating surface formed below the collision surface. A first clearance between an air-guiding direction distal end of the deflecting surface and the receiving surface is brought into communication to a downstream side of a filter of an air cleaner in a fresh-air intake direction so as to act as a main intake passage for fresh air.

First claim

What is claimed is:

1. An intake structure for an internal combustion engine, comprising:
a collision surface configured to face an inlet of a carburetor;
a deflecting surface configured to deflect a blowback flow, which is to diffuse after colliding against the collision surface, in one direction along the collision surface;
a receiving surface configured to receive the blowback flow deflected by the deflecting surface; and
a fuel-accumulating surface formed below the collision surface in the gravity direction,
wherein a first clearance between an air-guiding direction distal end of the deflecting surface and the receiving surface is brought into communication to a downstream side of a filter of an air cleaner in a fresh-air intake direction so as to act as a main intake passage for fresh air.

2. The intake structure for an internal combustion engine according to claim 1 , wherein a distance between the deflecting surface and the collision surface is shorter than a distance between the receiving surface and the collision surface.

3. The intake structure for an internal combustion engine according to claim 1 , wherein an air-guiding direction base end of the deflecting surface and a peripheral wall portion provided around the collision surface have no gap therebetween.

4. The intake structure for an internal combustion engine according to claim 1 , further comprising a rectifying surface configured to rectify a flow of the fresh air toward the first clearance, the rectifying surface being formed so as to be continuous with at least one of the air-guiding direction distal end of the deflecting surface and an upper end of the receiving surface.

5. The intake structure for an internal combustion engine according to claim 1 , wherein the deflecting surface comprises an inclined flat surface.

6. The intake structure for an internal combustion engine according to claim 1 , wherein:
the deflecting surface comprises a curved surface; and
a slope of a tangent of the deflecting surface gradually decreases in a direction toward the air-guiding direction distal end of the deflecting surface.

7. The intake structure for an internal combustion engine according to claim 1 , wherein the deflecting surface comprises a plurality of deflecting faces formed so as to guide the blowback flow in a stepwise manner.

8. The intake structure for an internal combustion engine according to claim 1 , herein the air-guiding direction base end of the deflecting surface is located closer to a center of the collision surface than the air-guiding direction distal end of the deflecting surface.

9. The intake structure for an internal combustion engine according to claim 1 , wherein the deflecting surface is formed at a position deviated horizontally from a vertical axis passing through the center of the collision surface.

10. The intake structure for an internal combustion engine according to claim 1 , further comprising a cutout configured to avoid interference with a choke plate for opening and closing the inlet,
wherein the cutout is formed at a position at which movement of the blowback flow toward the cutout is inhibited by the deflecting surface.

Assignees

• Yamabiko Corp

Inventors

• Mutoh Hiroki
• Miyamoto Masayoshi

Classifications

• F02M17/34

  Other carburettors combined or associated with other apparatus, e.g. air filters · CPC title

• F02M35/10262

  Flow guides, obstructions, deflectors or the like (for generating a charge motion in the cylinder F02B31/00; for re-atomising condensed fuel or homogenising fuel-air mixture F02M29/00) · CPC title

• F02M35/10078 Primary

  Connections of intake systems to the engine · CPC title

• F02M35/1017

  Small engines, e.g. for handheld tools, or model engines; Single cylinder engines · CPC title

• F02M35/10144

  Connections of intake ducts to each other or to another device · CPC title