Portable engine working machine and rotary carburetor incorporated therein

Patent metadata

Field	Value
Publication number	US-10634095-B2
Application number	US-201816159739-A
Country	US
Kind code	B2
Filing date	Oct 15, 2018
Priority date	Dec 2, 2016
Publication date	Apr 28, 2020
Grant date	Apr 28, 2020

Abstract

To improve responsiveness of fuel supply control, a rotary carburetor 100 has a nozzle 8 including a fuel discharge port 8a and a needle 10 disposed coaxially with the nozzle 8 and disposed with a portion inserted into the nozzle 8. The needle 10 can be displaced relative to the nozzle 8 to change an effective area of the fuel discharge port 8a. The rotary carburetor 100 has an electric motor 14 for displacing the needle 10 along an axis, and a drive mechanism component 12 interposed between the electric motor 14 and the needle 10 and converting a rotational movement of the electric motor into a linear movement.

First claim

What is claimed is:

1. A portable engine working machine comprising:
a rotary carburetor disposed in an intake passage of the portable engine working machine;
a rotatable valve main body received in a carburetor main body of the rotary carburetor, mechanically coupled to a throttle trigger operated by an operator, and rotated by an operation of the throttle trigger to change a throttle opening degree;
a cover member closing the carburetor main body receiving the rotatable valve main body;
a nozzle disposed on an axis of the rotatable valve main body and fixed to a carburetor main body, including a fuel discharge port supplying a fuel to an intra-carburetor air-fuel mixture passage;
a needle disposed coaxially with the nozzle and disposed with a portion inserted into the nozzle, the needle being displaced relative to the nozzle to change an effective area of the fuel discharge port so as to control an amount of a fuel discharged from the fuel discharge port;
an electric motor for displacing the needle along an axis; and
a drive mechanism component fixed to the cover member and interposed between the electric motor and the needle for converting a rotational movement of the electric motor into a linear movement, wherein
the rotatable valve main body is not vertically displaced when the rotatable valve main body is in rotational motion.

2. The portable engine working machine of claim 1 , wherein
the fuel discharge port is formed in a circumferential surface of the nozzle at a tip portion of the nozzle.

3. The portable engine working machine of claim 2 , wherein
the rotatable valve main body has a hollow throttle shaft extending on the axis of the rotatable valve main body, and
a throttle lever coupled to the hollow throttle shaft in a relatively non-rotatable manner and mechanically coupled to the throttle trigger, and wherein
the drive mechanism component is received in the throttle shaft.

4. The portable engine working machine of claim 3 , further comprising a position sensor disposed to surround a rotating member rotating in conjunction with an operation of the throttle trigger, wherein
a throttle opening degree is detected by the position sensor.

5. The portable engine working machine of claim 4 , wherein the rotating member is the throttle lever.

6. The portable engine working machine of claim 4 , wherein the rotating member is the rotatable valve main body.

7. A rotary carburetor disposed in an intake passage of a portable engine working machine comprising:
a rotatable valve main body received in a carburetor main body of the rotary carburetor, mechanically coupled to a throttle trigger operated by an operator, and rotated by an operation of the throttle trigger to change a throttle opening degree;
a cover member closing the carburetor main body receiving the rotatable valve main body;
a nozzle disposed on an axis of the rotatable valve main body and fixed to a carburetor main body, including a fuel discharge port supplying a fuel to an intra-carburetor air-fuel mixture passage;
a needle disposed coaxially with the nozzle and disposed with a portion inserted into the nozzle, the needle being displaced relative to the nozzle to change an effective area of the fuel discharge port so as to control an amount of a fuel discharged from the fuel discharge port;
an electric motor for displacing the needle along an axis; and
a drive mechanism component fixed to the cover member and interposed between the electric motor and the needle for converting a rotational movement of the electric motor into a linear movement, wherein
the rotatable valve main body is not vertically displaced when the rotatable valve main body is in rotational motion.

8. The portable engine working machine of claim 7 , wherein
the fuel discharge port is formed in a circumferential surface of the nozzle at a tip portion of the nozzle.

9. The rotary carburetor of claim 7 , wherein
the rotatable valve main body has a hollow throttle shaft extending on the axis of the rotatable valve main body, and
a throttle lever coupled to the throttle shaft in a relatively non-rotatable manner and mechanically coupled to the throttle trigger, and wherein
the drive mechanism component is received in the throttle shaft.

10. The rotary carburetor of claim 9 , further comprising a position sensor disposed to surround a rotating member rotating in conjunction with an operation of the throttle trigger, wherein
a throttle opening degree is detected by the position sensor.

11. The rotary carburetor of claim 10 , wherein the rotating member is the throttle lever.

12. The rotary carburetor of claim 10 , wherein the rotating member is the rotatable valve main body.

13. The rotary carburetor of claim 7 , wherein
the rotary carburetor is applied to a stratified scavenging engine, and wherein
the rotatable valve main body further includes an air passage supplying air to a scavenging passage of the portable engine working machine.

Assignees

• Yamabiko Corp

Inventors

• Nonaka Takumi
• Sato Genichi

Classifications

• F02B63/02

  for hand-held tools · CPC title

• F02D35/0053

  by means of a carburettor · CPC title

• F02D2400/06

  Small engines with electronic control, e.g. for hand held tools · CPC title

• F02M9/085 Primary

  Fuel spray nozzles in the throttling valves · CPC title

• F02M19/0207

  the cross-sectional area being changed electrically · CPC title