# US 8,770,172 B2 · Fuel shortage detecting apparatus for general-purpose engine > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,770,172 B2 - Document ID: US8770172B2 - Status: Granted - Kind: B2 - Application number: 13/218,913 - Filed: 2011-08-26 - Published: 2012-03-08 - Granted: 2014-07-08 - Earliest claimed: 2010-09-08 - Assignees: Honda Motor Co., Ltd. - Applicants: Takashi Hashizume; Masayuki Fukuhara - Inventors: Takashi Hashizume; Masayuki Fukuhara - Web page: https://patentgrep.com/patent/US8770172B2 ## CPC - F02D 41/042: {for stopping the engine} - F02D 31/002: {controlling air supply} - F02D 41/3082: {Control of electrical fuel pumps} - F02P 11/02: Preventing damage to engines or engine-driven gearing - F02D: CONTROLLING COMBUSTION ENGINES (vehicle fittings, acting on a single sub-unit only, for automatically controlling vehicle speed B60K31/00; conjoint control of vehicle sub-units of different type or different function, road vehicle drive control systems for purposes other than the control of a single sub-unit B60W) - F02P: IGNITION, OTHER THAN COMPRESSION IGNITION, FOR INTERNAL-COMBUSTION ENGINES; TESTING OF IGNITION TIMING IN COMPRESSION-IGNITION ENGINES ({anti-pollution means for internal-combustion engines F02B17/00}; specially adapted for rotary-piston or oscillating-piston engines F02B53/12; {ignition of gas turbine plants F02C7/26; ignition of jet propulsion plants F02K9/95; starting of combustion engines F02N9/00}; ignition of combustion apparatus in general, glowing plugs F23Q; measuring of physical variables in general G01; controlling in general G05; data processing in general G06; electrical components in general see Section H; {ignition coils H01F38/12}; sparking plugs H01T13/00) ## Abstract In an apparatus for detecting fuel shortage of a general-purpose internal combustion engine connectable to an operating machine to be used as a prime mover of the machine, the engine being supplied with fuel stored in a tank and having an actuator adapted to open and close a throttle valve installed in an air intake pipe so as to achieve a desired engine speed set by an operator, comprising a fuel shortage condition detector adapted to detect whether the engine is in a fuel shortage condition, and an engine stopper adapted to stop the engine when the engine is detected to be in the fuel shortage condition. With this, it becomes possible to detect whether the engine having the electronic governor is in the fuel shortage condition, thereby preventing occurrence of trouble such as afterburning. ## Claims ### Claim 1 An apparatus for detecting fuel shortage of a general-purpose internal combustion engine connectable to an operating machine to be used as a prime mover of the machine, the engine being supplied with fuel stored in a tank and having an actuator adapted to open and close a throttle valve installed in an air intake pipe so as to achieve a desired engine speed set by an operator, comprising: a fuel shortage condition detector adapted to detect whether the engine is in a fuel shortage condition; and an engine stopper adapted to stop the engine when the engine is detected to be in the fuel shortage condition, wherein the fuel shortage condition detector detects whether the engine is in the fuel shortage condition based on a speed of the engine and an opening of the throttle valve. ### Claim 2 (depends on 1) The apparatus according to claim 1, wherein the fuel shortage condition detector detects whether the speed of the engine is in a low-speed condition where it is less than a predetermined speed and the opening of the throttle valve is in a wide-open throttle condition where it is greater than a predetermined opening and whether the low-speed condition and the wide-open throttle condition continue for a prescribed time or more, and detects that the engine is in the fuel shortage condition when the low-speed condition and the wide-open throttle condition are detected to continue for the prescribed time or more. ### Claim 3 (depends on 1) The apparatus according to claim 1, further including: a manipulation switch installed to be manipulated by the operator to produce an output indicative of start/stop of the engine, and the fuel shortage condition detector detects whether the engine is in the fuel shortage condition after the manipulation switch was turned on and start operation of the engine has been completed. ### Claim 4 (depends on 1) The apparatus according to claim 1, wherein the engine stopper stops the engine by stopping supply of the fuel. ### Claim 5 (depends on 1) The apparatus according to claim 1, wherein the engine stopper stops the engine by stopping ignition. ### Claim 6 An apparatus for detecting fuel shortage of a general-purpose internal combustion engine connectable to an operating machine to be used as a prime mover of the machine, the engine being supplied with fuel stored in a tank and having an actuator adapted to open and close a throttle valve installed in an air intake pipe so as to achieve a desired engine speed set by an operator, comprising: a fuel shortage condition detector adapted to detect whether the engine is in a fuel shortage condition; and an engine stopper adapted to stop the engine when the engine is detected to be in fuel shortage condition, wherein the engine is connected to a fuel supply system having a fuel pump operated by an electric motor to pump the fuel stored in the tank to be supplied to the engine and the fuel shortage condition detector detects whether the engine is in the fuel shortage condition based on operation of the fuel pump. ### Claim 7 (depends on 6) The apparatus according to claim 6, wherein the fuel shortage condition detector detects whether the engine is in the fuel shortage condition based on a current value supplied to the motor of the fuel pump. ### Claim 8 (depends on 7) The apparatus according to claim 7, wherein the fuel shortage condition detector compares the current value supplied to the motor of the fuel pump with a first threshold value and detects that the engine is in the fuel shortage condition when the current value is less than the first threshold value. ### Claim 9 (depends on 8) The apparatus according to claim 8, wherein the fuel shortage condition detector compares the current value supplied to the motor of the fuel pump with the first threshold value and detects that the engine is in the fuel shortage condition when the current value is less than the first threshold value continuously for a first predetermined time. ### Claim 10 (depends on 7) The apparatus according to claim 7, wherein the fuel shortage condition detector detects that the engine is in the fuel shortage condition when a variation width of the current value supplied to the motor of the fuel pump is greater than a second threshold value and the current value is less than a third threshold value. ### Claim 11 (depends on 10) The apparatus according to claim 10, wherein the fuel shortage condition detector detects that the engine is in the fuel shortage condition when the variation width of the current value supplied to the motor of the fuel pump during a second predetermined time is greater than the second threshold value and an average of the current value during a third predetermined time is less than the third threshold value. ### Claim 12 (depends on 11) The apparatus according to claim 11, wherein the fuel shortage condition detector detects that the engine is in the fuel shortage condition when the variation width of the current value supplied to the motor of the fuel pump during the second predetermined time is greater than the second threshold value continuously for a fourth predetermined time and the average of the current value during the third predetermined time is less than the third threshold value continuously for the fourth predetermined time. ### Claim 13 (depends on 6) The apparatus according to claim 6, wherein the fuel shortage condition detector detects whether power supply voltage falls within a predetermined range and detects whether the engine is in the fuel shortage condition when the power supply voltage falls within the predetermined range. ### Claim 14 A method for detecting fuel shortage of a general-purpose internal combustion engine connectable to an operating machine to be used as a prime mover of the machine, the engine being supplied with fuel stored in a tank and having an actuator adapted to open and close a throttle valve installed in an air intake pipe so as to achieve a desired engine speed set by an operator, comprising the steps of: detecting whether the engine is in a fuel shortage condition; and stopping the engine when the engine is detected to be in the fuel shortage condition, wherein the step of detecting detects whether the engine is in the fuel shortage condition based on a speed of the engine and an opening of the throttle valve. ### Claim 15 (depends on 14) The method according to claim 14, wherein the step of detecting detects whether the speed of the engine is in a low-speed condition where it is less than a predetermined speed and the opening of the throttle valve is in a wide-open throttle condition where it is greater than a predetermined opening and whether the low-speed condition and the wide-open throttle condition continue for a prescribed time or more, and detects that the engine is in the fuel shortage condition when the low-speed condition and the wide-open throttle condition are detected to continue for the prescribed time or more. ### Claim 16 (depends on 14) The method according to claim 14, wherein the step of detecting detects whether the engine is in the fuel shortage condition after the manipulation switch installed to be manipulated by the operator to produce an output indicative of start/stop of the engine was turned on and start operation of the engine has been completed. ### Claim 17 (depends on 14) The method according to claim 14, wherein the step of stopping stops the engine by stopping supply of the fuel. ### Claim 18 (depends on 14) The method according to claim 14, wherein the step of stopping stops the engine by stopping ignition. ### Claim 19 A method for detecting fuel shortage of a general-purpose internal combustion engine connectable to an operating machine to be used as a prime mover of the machine, the engine being supplied with fuel stored in a tank and having an actuator adapted to open and close a throttle valve installed in an air intake pipe so as to achieve a desired engine speed set by an operator, comprising the steps of: detecting whether the engine is in a fuel shortage condition; and stopping the engine when the engine is detected to be in the fuel shortage condition, wherein the engine is connected to a fuel supply system having a fuel pump operated by an electric motor to pump the fuel stored in the tank to be supplied to the engine and the step of detecting detects whether the engine is in the fuel shortage condition based on operation of the fuel pump. ### Claim 20 (depends on 19) The method according to claim 19, wherein the step of detecting detects whether the engine is in the fuel shortage condition based on a current value supplied to the motor of the fuel pump. ### Claim 21 (depends on 20) The method according to claim 20, wherein the step of detecting compares the current value supplied to the motor of the fuel pump with a first threshold value and detects that the engine is in the fuel shortage condition when the current value is less than the first threshold value. ### Claim 22 (depends on 21) The method according to claim 21, wherein the step of detecting compares the current value supplied to the motor of the fuel pump with the first threshold value and detects that the engine is in the fuel shortage condition when the current value is less than the first threshold value continuously for a first predetermined time. ### Claim 23 (depends on 20) The method according to claim 20, wherein the step of detecting detects that the engine is in the fuel shortage condition when a variation width of the current value supplied to the motor of the fuel pump is greater than a second threshold value and the current value is less than a third threshold value. ### Claim 24 (depends on 23) The method according to claim 23, wherein the step of detecting detects that the engine is in the fuel shortage condition when the variation width of the current value supplied to the motor of the fuel pump during a second predetermined time is greater than the second threshold value and an average of the current value during a third predetermined time is less than the third threshold value. ### Claim 25 (depends on 24) The method according to claim 24, wherein the step of detecting detects that the engine is in the fuel shortage condition when the variation width of the current value supplied to the motor of the fuel pump during the second predetermined time is greater than the second threshold value continuously for a fourth predetermined time and the average of the current value during the third predetermined time is less than the third threshold value continuously for the fourth predetermined time. ### Claim 26 (depends on 19) The method according to claim 19, wherein the step of detecting detects whether power supply voltage falls within a predetermined range and detects whether the engine is in the fuel shortage condition when the power supply voltage falls within the predetermined range.