Air-leading type stratified scavenging two-stroke internal combustion engine, and engine working machine

Patent metadata

Field	Value
Publication number	US-11913371-B2
Application number	US-202017765843-A
Country	US
Kind code	B2
Filing date	Sep 24, 2020
Priority date	Oct 4, 2019
Publication date	Feb 27, 2024
Grant date	Feb 27, 2024

Abstract

Provided is an air leading type stratified scavenging two-stroke internal combustion engine including an air passage configured to allow supply of air to a scavenging passage configured to allow communication between a crank chamber and a combustion chamber, at least one sensor configured to detect an operating condition of an engine, and a fuel valve configured to control fuel supply to the air passage based on detection performed by the at least one sensor. The fuel supply to the air passage is controlled by the fuel valve at times other than start and idling of the engine or at needed times in addition to the start or the idling of the engine.

First claim

The invention claimed is:

1. An air leading type stratified scavenging two-stroke internal combustion engine, comprising:
an air passage configured to allow supply of air to a scavenging passage configured to allow communication between a crank chamber and a combustion chamber;
at least one sensor configured to detect an operating condition of the engine; and
a fuel valve configured to control fuel supply to the air passage based on detection performed by the at least one sensor,
wherein
the fuel supply to the air passage is controlled by the fuel valve at times other than start and idling of the engine or at needed times in addition to the start or the idling of the engine, and
the at least one sensor includes any one of a sensor configured to estimate a temperature of the engine, a sensor configured to estimate an accelerating operation of the engine, which is performed by an operator, and a sensor configured to estimate a decelerating operation of the engine, which is performed by the operator.

2. The air leading type stratified scavenging two-stroke internal combustion engine according to claim 1 , wherein the at least one sensor comprises a rotation speed sensor configured to detect a rotation speed of the engine.

3. The air leading type stratified scavenging two-stroke internal combustion engine according to claim 1 , wherein the sensor configured to estimate the temperature of the engine comprises a temperature sensor configured to directly detect a temperature.

4. The air leading type stratified scavenging two-stroke internal combustion engine according to claim 3 , wherein the temperature sensor is mounted to a cylinder.

5. The air leading type stratified scavenging two-stroke internal combustion engine according to claim 1 , further comprising a control configured to stop the engine immediately after detection of a predetermined high temperature of the engine.

6. The air leading type stratified scavenging two-stroke internal combustion engine according to claim 1 , further comprising a piston configured to slidably reciprocate inside a cylinder coupled to the crank chamber, the piston having a peripheral surface with piston grooves configured to bring the air passage and the scavenging passage into communication with each other at predetermined timing.

7. The air leading type stratified scavenging two-stroke internal combustion engine according to claim 1 , further comprising an air-fuel mixture passage communicating with the crank chamber,
wherein the fuel valve is installed in a component obtained by integrally forming the air passage and the air-fuel mixture passage.

8. The air leading type stratified scavenging two-stroke internal combustion engine according to claim 1 , wherein the fuel valve is installed in an intake pipe being separate from a carburetor.

9. The air leading type stratified scavenging two-stroke internal combustion engine according to claim 1 , wherein the fuel valve is installed in a carburetor.

10. An engine-driven working machine, comprising an air leading type stratified scavenging two-stroke internal combustion engine as a power source,
wherein the air leading type stratified scavenging two-stroke internal combustion engine, comprising:
an air passage configured to allow supply of air to a scavenging passage configured to allow communication between a crank chamber and a combustion chamber;
at least one sensor configured to detect an operating condition of the engine; and
a fuel valve configured to control fuel supply to the air passage based on detection performed by the at least one sensor,
wherein
the fuel supply to the air passage is controlled by the fuel valve at times other than start and idling of the engine or at needed times in addition to the start or the idling of the engine, and
the at least one sensor includes any one of a sensor configured to estimate a temperature of the engine, a sensor configured to estimate an accelerating operation of the engine, which is performed by an operator, and a sensor configured to estimate a decelerating operation of the engine, which is performed by the operator.

Assignees

• Yamabiko Corp

Inventors

• Kobayashi Yuta
• Yamazaki Takahiro

Classifications

• F02B25/20 Primary

  Means for reducing the mixing of charge and combustion residues or for preventing escape of fresh charge through outlet ports not provided for in, or of interest apart from, subgroups F02B25/02 - F02B25/18 · CPC title

• F02D41/042

  for stopping the engine · CPC title

• F02M7/12

  Other installations, with moving parts, for influencing fuel/air ratio, e.g. having valves (F02M7/24 takes precedence) · CPC title

• F02D2200/021

  Engine temperature · CPC title

• F02D2200/101

  Engine speed · CPC title