Throttle system for general-purpose engine

• US 6,761,145 B2
• Filed: 04/18/2003
• Issued: 07/13/2004
• Est. Priority Date: 04/19/2002
• Status: Expired due to Fees

• Current Assignee: Honda Giken Kogyo Kabushiki Kaisha (Honda Motor Company)
• Original Assignee: Honda Giken Kogyo Kabushiki Kaisha (Honda Motor Company)
• Inventors: Matsuda, Hayato, Watanabe, Sei
• Primary Examiner(s): Kwon, John
• Application Number:
  US10/418,129
• Publication Number:
  US 20030196638A1
• Time in Patent Office: 452 Days
• Field of Search: 123/342, 123/400, 123/403, 123/442
• US Class Current: 123/342
• CPC Class Codes: F02D 11/04 characterised by mechanical control linkages F02D11/06 takes precedence
• CPC Class Codes: F02D 2009/0261 having a specially shaped transmission member, e.g. a cam, specially toothed gears, with a clutch
• CPC Class Codes: F02D 9/1065 Mechanical control linkage between an actuator and the flap, e.g. including levers, gears, springs, clutches, limit stops of the like

Abstract

A throttle system for a general-purpose engine, having an actuator (motor) connected to a throttle valve to open or close it so as to regulate amount of intake air. An output transmission mechanism constituted as a link mechanism or a gear mechanism is provided between the actuator and the throttle valve to transmit an output of the actuator to the throttle value such that an output of the mechanism relative to the output of the actuator when the throttle valve is fully closed, is smaller than that when the throttle value is not fully closed. With this, the system can finely open and close the throttle valve when its opening is small and can open and close it at high speed when its opening is large, while preventing throttle valve seizing.

Claims

1. A throttle system for a general-purpose engine, having an actuator connected to a throttle valve of the engine, the actuator being displaceable to open or close the throttle valve so as to regulate amount of intake air, comprising:

an output transmission mechanism provided between the actuator and the throttle valve to transmit an output of the actuator to the throttle value such that an output of the mechanism relative to the output of the actuator when the throttle valve is closed is smaller than that when the throttle valve is not closed.

2. A throttle system according to claim 1, wherein the output transmission mechanism is constituted as a link mechanism having;

a link lever connected to an output shaft of the actuator; and

a throttle lever whose one end is connected to the link lever to be displaceable relative to the link lever and whose other end is connected to a rotating shaft of the throttle valve;

wherein the link lever and the throttle lever are connected to transmit the output of the actuator to the throttle value such that displacement of the mechanism relative to the output of the actuator is minimum when the throttle valve is closed.

3. A throttle system according to claim 2, wherein the throttle lever is formed with a link pin that is movable in a hole (80a1) formed at the link lever.

4. A throttle system according to claim 3, wherein the hole is an arcuate hole having a same radius of curvature as a rotational radius of curvature of a locus of the link pin.

5. A throttle system according to claim 1, wherein the output transmission mechanism is constituted as a gear mechanism having;

a first gear connected to an output shaft of the actuator; and

a second gear connected to a rotating shaft of the throttle valve;

wherein the first gear and the second gear are meshed together such that a rotation angle of the second gear relative to a rotation angle of the first gear is minimum when the throttle valve is closed.

6. A throttle system according to claim 5, wherein the output shaft of the actuator is connected to the first gear at a location apart from a center of the first gear, and the rotating shaft of the throttle valve is connected to the second gear at a location apart from a center of the second gear.

7. A throttle system according to claim 6, wherein the first and second gears are eccentric gears.

8. A throttle system according to claim 6, wherein the first and second gears are elliptic gears.

9. A throttle system according to claim 7, wherein the first and second gears are elliptic gears.