Electronic control governor

• US 8,176,895 B2
• Filed: 02/26/2008
• Issued: 05/15/2012
• Est. Priority Date: 03/01/2007
• Status: Active Grant

• Current Assignee: Yanmar Power Technology Co., Ltd. (Yanmar Holdings Co., Ltd.)
• Original Assignee: Yanmar Company Limited (Yanmar Holdings Co., Ltd.)
• Inventors: Kusaka, Hokuto, Shiomi, Hideo, Takagawa, Isao
• Primary Examiner(s): MOULIS, THOMAS N
• Application Number:
  US12/529,285
• Publication Number:
  US 20100108030A1
• Time in Patent Office: 1,540 Days
• Field of Search: 123/357, 123/446, 123/447, 123/506, 701/102, 701/103, 701/104
• US Class Current: 123/357
• CPC Class Codes: F02D 2041/2027 Control of the current by pulse width modulation or duty cycle control
• CPC Class Codes: F02D 31/007 controlling fuel supply
• CPC Class Codes: F02D 41/1408 Dithering techniques
• CPC Class Codes: F02D 41/20 Output circuits, e.g. for controlling currents in command coils

Abstract

In an electronic control governor that adjusts the amount of fuel supplied to an engine so as to coincide an engine rotation speed with a target rotation speed, by driving an actuator for actuating a fuel adjusting mean due to an actuator driving current overlapped with a dither current, an amplitude or frequency of the dither current is changed, corresponding to a change in the supply quantity of the actuator driving current. Or, the amplitude and frequency of the dither current are changed corresponding to a change in the engine rotation speed. Alternatively, a ratio between turn-on time and turn-off time during one period of the dither current is changed, depending on the velocity ratio between the increased velocity and the decreased velocity of the actuator driving current. Preferably, the ratio of the turn-on time to one period of the dither current is set at 20 to 40%.

Claims

1. An electronic control governor comprising:

a fuel adjustment means for adjusting an amount of fuel supplied to an engine; and

an actuator that is driven by supply of an actuator driving current overlapped with a dither current so as to drive the fuel adjustment means, thereby coinciding an engine rotation speed with a target rotation speed,

wherein the electronic control governor stores a map indicating a relation of an amplitude of the dither current to an engine load, calculates an actual engine load, and controls the amplitude of dither current based on the map so as to correspond to the calculated actual engine load, thereby bringing an amplitude of the actuator driving current close to an adequate value regardless of change in supply quantity of the actuator driving current according to change of the engine load,

wherein the whole region of the engine load in the map is set to include a low load region, a high load region, and a middle load region between the low and high load regions,

wherein any dither current corresponding to engine load in the low load region is set to have a fixed first amplitude,

wherein any dither current corresponding to engine load in the high load region is set to have a fixed second amplitude that is smaller than the first amplitude, and

wherein an amplitude of the dither current corresponding to engine load in the middle load region is set to be gradually reduced from the first amplitude to the second amplitude as the engine load increases.

2. An electronic control governor comprising:

a fuel adjustment means for adjusting an amount of fuel supplied to an engine; and

an actuator that is driven by supply of an actuator driving current overlapped with a dither current so as to drive the fuel adjustment means, thereby coinciding an engine rotation speed with a target rotation speed,

wherein the electronic control governor stores a map indicating a relation of a period of the dither current to an engine load, calculates an actual engine load, and controls the period of dither current based on the map so as to correspond to the calculated actual engine load, thereby bringing an amplitude of the actuator driving current close to an adequate value regardless of change in supply quantity of the actuator driving current according to change of the engine load,

wherein the whole region of the engine load in the map is set to include a low load region, a high load region, and a middle load region between the low and high load regions,

wherein any dither current corresponding to engine load in the low load region is set to have a fixed first period,

wherein any dither current corresponding to engine load in the high load region is set to have a fixed second period that is shorter than the first period, and

wherein a period of the dither current corresponding to engine load in the middle load region is set to be gradually shortened from the first period to the second period as the engine load increases.