Gas-diesel dual fuel engine

• US 4,603,674 A
• Filed: 06/16/1982
• Issued: 08/05/1986
• Est. Priority Date: 06/19/1981
• Status: Expired due to Fees

• Current Assignee: Yanmar Diesel Engine Co., Ltd. (Yanmar Holdings Co., Ltd.)
• Original Assignee: Yanmar Diesel Engine Co., Ltd. (Yanmar Holdings Co., Ltd.)
• Inventors: Tanaka, Mitsuo
• Primary Examiner(s): Miller, Carl Stuart
• Application Number:
  US06/389,093
• Time in Patent Office: 1,511 Days
• Field of Search: 123/357, 123/299, 123/300, 123/27 GE, 123/575, 123/576, 123/577, 123/358, 123/359
• US Class Current: 123/575
• CPC Class Codes: F02B 2201/064 Liquid and gas
• CPC Class Codes: F02B 3/06 with compression ignition compression ignition engines using air or gas for blowing fuel into compressed air in cylinder F02B13/02
• CPC Class Codes: F02D 19/0607 to adjust the fuel mass or volume flow
• CPC Class Codes: F02D 19/0628 Determining the fuel pressure, temperature or flow, the fuel tank fill level or a valve position
• CPC Class Codes: F02D 19/0678 Pressure or flow regulators therefor; Fuel metering valves therefor
• CPC Class Codes: F02D 19/105 operating in a special mode, e.g. in a liquid fuel only mode for starting
• CPC Class Codes: Y02T 10/30 Use of alternative fuels, e.g. biofuels

Abstract

A gas-diesel dual fuel engine operative with both a gaseous fuel and a diesel fuel oil. The engine has an electronic governor circuit adapted to receive both a speed signal representing actual speed of engine and a set speed signal representing a predetermined command speed of the engine, electric actuators adapted to actuate a diesel fuel injection pump and a gaseous fuel regulating valve, respectively, in response to the signal from the electronic governor circuit, and a mode switching control circuit connected to the electronic governor circuit and adapted to switch the operation of the electric actuators between a diesel fuel operation mode and a gaseous fuel operation mode.

Claims

1. In a gas-diesel dual fuel engine apparatus having a diesel engine, a diesel fuel supply system including a diesel fuel injection pump, a gaseous fuel supply system including gaseous fuel regulating valve, and a governing and controlling device for governing the speed of said engine and controlling the switchover of the operation of said engine between a diesel fuel mode and a gaseous fuel mode;

the improvement that said governing and controlling device comprises;

(a) first and second electronic governor means adapted to compare a speed signal representing the actual operating speed of said diesel engine with a set speed signal representing the set speed thereof and to perform a proportional plus integral plus differential operation on the basis of the difference therebetween for outputting respective control signals, according to the difference between said two speed signals, for the engine'"'"'s diesel fuel mode and gaseous fuel mode;

(b) a pair of electric actuator means having respective power amplifier circuits and mechanically connected to said diesel fuel injection pump and said gaseous fuel regulating valve, respectively, for the actuation thereof;

(c) mode switching control means for controlling the switch-over of said governing and controlling device between the engine'"'"'s diesel fuel operation mode and gaseous fuel operation mode, said mode switching control means being adapted to generate command signals for fully closing said gaseous fuel regulating value when the engine is in the diesel fuel operation mode and for operating said diesel fuel injection pump to feed said diesel engine with a predetermined amount of a diesel fuel as pilot injection fuel when the engine is in the gaseous fuel operation mode; and

(d) signal selecting means connecting said first and second electronic governor means and said mode switching control means to said pair of electric actuator means for selectively delivering said control signals and said command signals, said signal selecting means being controlled by said mode switching control means so that when the engine is in the diesel fuel operation mode, the appropriate control signal is delivered to said electric actuator means connected with said diesel fuel injection pump to operate said pump and the associated command signal is delivered to said electric actuator means connected with said gaseous fuel regulating valve to close said valve, while when the engine is in the gaseous fuel operation mode, the then appropriate control signal is delivered to said electric actuator means connected with said gaseous fuel regulating valve and the then associated command signal is delivered to said electric actuator means connected with said diesel fuel injection pump to operate said pump for the pilot injection;

(e) said signal selecting means comprising first and second minimum value selection circuits which connect said first and second electronic governor means to respective electric actuator means and each of which is adapted to compare the respective control signal from the corresponding electronic governor means with the associated command signal from said mode switching control means and to output only parts of said control signals lower than and equal to said command signals, and said mode switching control means comprising a voltage generating circuit which is adapted to generate a zero voltage signal, a pilot injection signal, a false set speed signal higher than said set speed signal and an upper limit voltage signal respresenting the upper limit of usable voltage, said voltage generating circuit being operable to input said zero voltage signal and said upper limit voltage signal to said second and said first minimum value selection circuits, respectively, when the engine is in the diesel fuel mode so that said gaseous fuel regulating valve is fully closed and said diesel fuel injection pump is operated according to said control signal from said first electronic governor means, said voltage generating circuit being further operable to input said upper limit voltage signal, said false set speed signal and said pilot injection signal to said second minimum value selection circuit, said first electronic governor means and said first minimum value selection circuit, respectively, when the engine is in the gaseous fuel mode so that said gaseous fuel regulating valve is operated according to said control signal from said second electronic governor means and said first electronic governor means outputs a control signal higher than said pilot injection signal by means of an integral action of the proportional plus integral plus differential operation to keep said diesel fuel injection pump operating to feed said engine with the predetermined amount of pilot injection fuel.