Futaba Denshi Kogyo K.k.

Futaba Denshi Kogyo Kabushiki Kaisha

Norio Matsuda

Kazuyuki Tanaka

Michio Yamamoto

A fuel regulation apparatus of an engine for a model which is possible to regulate the flow rate of the fuel according to the rotational frequency of the engine is provided. A main body,of a fuel regulation apparatus,is provided with a fuel inlet,, a fuel outlet,, and an air inlet,to which air pressure from a crankcase is applied. The inlet,and the outlet,are connected therewith through a passage,having a seat face,. A regulating valve,is placed in the passage,to close the seat face,. A spring,pushes the regulating valve,in such a direction as to close the seat face. The other end of the regulating valve,is in contact with a piston,. A position of an air inlet,can be adjusted by a screw,. The spring pushes the piston,in such a direction as to open the seat face,. The outlet,is connected to a fuel injection apparatus. The fuel injection apparatus injects the fuel into a crankcase. The piston is pushed according to air pressure in the crankcase,corresponding to rotational frequency and the seat face is opened. The flow rate can be controlled according to the rotational frequency of the engine. The fuel which is apt to be insufficient at the time of high speed can be increased and the fuel which is apt to be dense at the time of low speed can be throttled.

Fuel regulation apparatus and fuel injection apparatus of engine for model

A method and apparatus for controlling an engine for models include setting an injection period for fuel in accordance with an amount of fuel per cycle required for operating of the engine; judging whether the injection period is below a minimum injection period controllable in a fuel injection apparatus of the engine, selecting an intermittent injection data corresponding to the injection period when the injection period is below the minimum injection period; and intermittently injecting fuel into the fuel injection apparatus for a controllable injection period at an injection timing based on the selected intermittent injection data.

Controlling apparatus for engine for model and controlling method therefor

A fuel injection device for a model engine capable of injecting fuel directly into a combustion chamber of the engine, to thereby insure stable feeding of fuel even under severe operational conditions. A check valve is arranged in a fuel injection passage or port to prevent backflow of fuel. Such construction permits the fuel injection device to be mounted directly on a cylinder of the engine to inject fuel directly into a combustion chamber of the engine, unlike the prior art. Also, in the present invention, pressurized air held in an air holding space may be injected together with fuel only during fuel injection, resulting in fuel being injected in the form of a fine mist-like shape.

Fuel injection device for model engine

A fuel injection system having no fuel leakage and a high speed response includes both an outlet opening of a fuel supply passage 44 and an inlet opening 59 of an injection passage 56 are provided facing to a communication space 54 formed on the one end face of a valve box 51. A diaphragm 62 seals the communicating space of a valve box 51. A ridge 64 of the diaphragm 62 shuts the supply passage and injection passage. A valve body 70 driven by a solenoid coil 65 is combined with the diaphragm 62. The valve body 70 is pressed by a plate spring 71. While a current is not supplied to the solenoid coil 65, the plate spring 71 presses the valve body 70, and the ridge 64 of the diaphragm 62 closes the inlet opening 59 of the injection passage 56. Fuel is not injected. While a current is supplied to the solenoid coil 65, the valve body 70 is attracted toward a magnetic core 66. The ridge 64 leaves from the valve box 51, and the injection passage 56 is communicated to the supply passage 55 through the communication space 54. Fuel is injected. The valve body 70 does not receive resistance force from fuel, and a small force of the solenoid coil is sufficient for functioning. Fuel does not enter into the box 53, therefore fuel does not leak from a hole 69 for guiding a power supply wire 68 to the outside.

Fuel injection system of engine for models

Air pressure which is proportional to the rotation speed of an engine is generated in a crank chamber 2 during operation. The crank chamber 2 is communicated to a fuel tank 10 having sealed structure with interposition of a check valve 25. Air pressure which is proportional to the rotation speed of the engine is applied to fuel in the fuel tank 10. The fuel tank 10 is communicated to the fuel injection system 30. The fuel injection system 30 opens its injection orifice only when power is supplied to a solenoid coil and injects supplied fuel into a combustion chamber. Because air pressure which is proportional to the rotation speed of the engine is applied to fuel, through each fuel injection time is constant, fuel which is proportional to the rotation speed can be injected. In particular, a shorter injection time is sufficient for high rotation speed operation in comparison with conventional fuel injection time, thereby power consumption of the fuel injection system 30 is reduced. Fuel injection rate is stabilized and the rotation stability at high speed is improved. This invention provides an engine for models in which power consumption of the electronic controlled fuel injection system is reduced and fuel is supplied adequately to the rotation speed.

Engine for models

An engine for radio controlled models includes an internal combustion engine and a radio control receiver having a control unit for generating a fuel injection signal to control the supply of fuel to the internal combustion engine and a throttle adjusting signal to control an opening of a throttle value. The control unit provides a fuel injection signal based on fuel injection timing which is derived from a stroke signal and control unit provides a fuel injection timing signal to cause the fuel injector of the internal combustion engine to inject fuel into the combustion chamber of the engine.

Engine for models and method for controlling engine for models

Fuel is supplied stably to the engine for models under severe operational conditions. The magnetic core 34 is inserted in the solenoid coil 32 in the box 31. The movable valve body 38 is provided in the box 31. The valve body 38 is pressed by the plate spring 44 so as to close the fuel injection opening 37. The check valve 24 is provided on the fuel feeding passage 48. The diaphragm partitions between the air pressure supply passage 25 and the internal of the box 31. The pulsatory air pressure of about 20 to 100 kPa generated in the crank chamber is applied to the fuel in the box 31 through the diaphragm 26. Fuel is introduced into the fuel injector without pressurization and confined by the check valve, and the fuel is pressurized using air which is not affected very much by the force due to acceleration. The air pipe 27 is fixed to the valve body 38 and diaphragm 26, and communicates between the air pressure supply passage 25 and fuel injection opening 37. The fuel introduced into the fuel injector 30 is confined by the check valve 24, and is pressurized with the pulsatory air pressure from the crank chamber at a constant pressure. When injection, air is injected and injected fuel changes to mist. The supply of fuel is stable even under severe operational conditions, the combustion efficiency is improved, and the output of the engine is increased.

Fuel injector of an engine for models

Fuel to which a predetermined pressure is applied is supplied to an electronically controlled fuel injection system of a engine for models in order to improve the rotation stability during low speed operation and the response to rapid acceleration or deceleration. The pulsatory air pressure is generated in a crank chamber of a engine for models during operation. An air pressure intake guide 51 of a fuel pressure control valve 1 receives air pressure from the crank chamber. The air intake guide is provided with an excessive pressure leak valve the actuation pressure of which is adjustable. The air pressure intake guide communicates with interposition of a check valve 56 to a controlled air pressure supply passage 54 which communicates to a fuel tank. The check valve 56 supplies the positive pressure of the pulsatory air pressure from the controlled air pressure supply passage to the internal of the fuel tank. All the positive air pressure supplied to the air pressure intake guide 51 is supplied to the fuel tank when the pressure in the fuel tank is below a specified pressure. The air pressure supplied to the air pressure intake guide 51 actuates a control ball 60 of the excessive pressure leak valve 57 and is released to the outside. The check valve 56 prevents the air pressure in the fuel tank from flowing inversely.

Fuel pressure control valve for engines of models

In a fuel injector magnetic core is inserted in the solenoid coil in the box. The fuel feeding passage is provided in the magnetic core. The movable valve body which moves up to the magnetic core magnetically is provided in the box. The valve body has a flow passage which communicates to the feeding passage. The valve body is forced to be pressed by the plate spring so as to be in contact with the valve box so as to close the fuel injection orifice. The check valve is provided on the fuel feeding passage. An air pressure of about 20 to 100 kPa generated in the crank chamber of the engine is applied to fuel in the box through the diaphragm. Fuel is introduced into the fuel injector without pressurization and confined by the check valve, and the fuel is pressurized using air which is not affected very much by the force due to acceleration. Fuel is fed stably even under severe operational conditions, the engine will not stall due to insufficient or excessive feeding of fuel. The fuel injector injects fuel in the movement direction of the model plane. The fuel injector is located ahead of the pressurized fuel tank in the movement direction of the model plane. The fuel injector is provided with the over pressure control valve for releasing the fuel to the outside when the internal fuel pressure increases and the negative pressure control valve for introducing the air pressure in the fuel tank into the internal when the internal fuel pressure decreases.

Growing community of inventors

Mobara, Japan

Norio Matsuda