JP2794295B2 - Gas engine generator - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a gas engine power generation device that drives a generator that also serves as a starter motor by a glow ignition gas engine that ignites using a glow plug.

BACKGROUND OF THE INVENTION Conventionally, a glow ignition system has been widely used for a model engine and the like. The glow plug used in the glow ignition system has a heat generating portion that glows red by the supply of electric current.The glow plug glows the heat only when the engine starts, cuts off the current after the engine starts, and self-ignites by the combustion heat. It has the feature that it is unnecessary or very simple.

However, this glow ignition method is suitable for a model engine that uses alcohol fuel with a wide combustible concentration range of the air-fuel mixture. It stops and cannot be used. Therefore, it is conceivable that the glow current continues to flow even after the engine is started. However, since the combustion state and the combustion temperature change greatly between the start and the operation of the engine, there is a problem that the life of the glow plug becomes extremely short and good operating performance cannot be obtained when the glow plug is continuously energized. there were. On the other hand, the emergence of a simple power generator that drives a generator using a glow ignition type engine having such a simple structure has been awaited.

(Object of the Invention) The present invention has been made in view of such circumstances,
An object of the present invention is to provide a simple gas engine power generation device that can extend the life of a glow plug while obtaining good engine operation performance when driving a starter / generator using a glow ignition type gas engine. And

(Constitution of the Invention) According to the present invention, it is an object of the present invention to provide a gas engine power generator that drives a generator also serving as a starter motor by a glow ignition gas engine that uses gas as fuel and ignites with a glow plug. A starter switch that is turned on when the engine is started, and a small current supplied to the glow plug during the ON period of the operation switch, and the current of the glow plug is maintained during the ON period of the starter switch. A glow control circuit for increasing the engine speed, an engine speed detecting means for detecting the engine speed, and a solenoid valve for maintaining the engine speed substantially constant by controlling a gas supply amount. Achieved by an engine generator.

(Embodiment) FIG. 1 is a conceptual diagram of one embodiment of the present invention, FIG. 2 is a system diagram of an engine generator using this embodiment, FIG. 3 is a layout diagram of each part thereof, and FIG. FIG. 5 is a control block diagram of the valve, FIG. 5 is an output waveform diagram of each part, and FIG. 6 is a glow control circuit diagram.

In FIGS. 2 and 3, reference numeral 10 denotes a liquid-cooled two-cycle engine, and reference numeral 12 denotes a DC generator that also serves as a starter. That is, when the engine 10 starts, the generator 12 drives the engine 10 as a starter motor, and after the engine starts, the generator 10 is driven by the engine 10 to generate power. 14 is a radiator integrated with the electric fan 16, 18 is a water pump driven by the engine 10, 20
Is a pressure regulator, and the coolant circulates through a closed coolant passage composed of a cylinder, a cylinder head, a pump 18, a pressure regulator 20, and a radiator 14 of the engine 10. The pressure regulator 20 is made of a variable-capacity container made of an elastic material such as rubber, and absorbs a change in the volume of the coolant due to a change in temperature.

The engine 10 has a cylindrical crankshaft 10b opening to a crank chamber 10a as shown in FIG. 1, and intake air guided from an intake pipe 10c is introduced into a crank chamber 10a from a port 10d provided on the crankshaft 10b. Entering, scavenging passage 10e when piston descends
From the combustion chamber. A glow plug 10f is attached to this combustion chamber. The glow plug 10f has an element composed of a coil made of an alloy containing platinum as a main component.

In FIG. 3, reference numeral 22 denotes a case. A radiator 14, a pump 18, a pressure regulator 20, and an electric lubricating oil pump 25 are disposed on the right side of a battery 24 vertically placed inside the case. Outside air is sucked into the case 22 from the opening 26 on the right side surface. The engine 10 and the generator 12 are arranged on the left side of the battery 24. The exhaust gas of the engine 10 is discharged from the muffler 28 close to the left side surface of the case 22 through the opening 30 of the case 22 to the outside. Note that the engine 10, the generator 12, and the muffler 26 are
The air drawn into the case 22 by the fan 16 of the radiator 14 is guided into the air guide wall 32 by a fan 34 provided in the engine 10, and the generator 12, the engine 10, the muffler
It is discharged outside through the opening 30 through the periphery of 28.

Reference numeral 36 denotes a gas cylinder which stores a pressurized gas fuel such as liquefied butane gas or liquefied propane gas. The cylinder 36 is loaded with the cap 38 located on the left side of the case 22 opened. When the cylinder 36 is loaded, the tip of the cylinder 36
Connected to. This port 40 has a pressure regulator 41 and a fuel cock.
The fuel that has passed through the receptacle 40 is
(FIG. 3) and a solenoid valve 45 (FIG.
) To the intake pipe 10c of the engine 10.
The pressure regulator 41 controls the gas pressure of the cylinder 36 to a pressure slightly higher than the atmospheric pressure.

Reference numeral 46 denotes a cartridge type lubricating oil tank, which is loaded by opening a cap 48 on the right side of the case 22. When this tank 46 is loaded, its tip is connected to the receiving port 50, and lubricating oil is supplied from this receiving port 50 to the oil pump.
The air is supplied to the intake pipe 10c of the engine 10 through the air pipe 25.

Now, when the cock 42 is opened and the operation switch 72 on the upper surface of the gate 22 is pressed, the power is turned on. When the start switch 74 is further pressed, the generator 12 becomes a starter motor and drives the engine 10. The solenoid valves 44 and 45 are opened to supply fuel gas to the fuel tank 10 and the oil pump 25 is also started, and lubricating oil is supplied to the intake pipe.
Supplied to 10c.

When the engine 10 starts and the starter switch 74 is released, the generator 12 operates as an original generator. The output of the generator 12 is connected in parallel with the battery 24, and power is taken from the outlet 76. When the engine speed falls below a certain level, the solenoid valve 44 closes and the gas supply is stopped.

The solenoid valve 44 controls the gas flow according to the battery voltage V. In FIG. 4, reference numeral 100 denotes an engine rotation detecting means, a pulse generator 102 for detecting the engine speed, an F / V converter 104 for converting the output pulse to a voltage v (corresponding to the engine speed), and a voltage v the and a comparator 108 which compares the set voltage v ₂ of setter 106. 110 is a circuit for performing PI control of the voltage V of the battery 24, 112 is a pulse width control circuit, and 114 is an AND circuit.

In FIG. 6, reference numeral 120 denotes a glow control circuit, which comprises a pulse width control circuit. The circuit 120 outputs the glow current g ₂ to turn on and off at a constant duty ratio based on the ON signal a operation switch 72. The signal b of the starter switch 74 in the circuit 120 is also input to the glow current g ₁ The signal b is increased the duty ratio at the time of ON. That is, the glow current increases when the engine is started, and decreases after the engine is started.

When the operation switch 72 is turned on as described above, the signal a in FIG. 5 is turned on, and when the starter switch 74 is pressed, a large glow current g1 _first flows through the glow plug 10f, and the glow plug 10f quickly glows red. This slight delay in the glow current g ₁ starter current i to operate the motor 12 as a starter motor to flow, electromagnetic valve 44 opens therewith. Engine speed is detected from the pulse generator 102, the speed signal is converted to an analog voltage v in F / V converter 104 is further compared with a set value v ₂ by the comparator 108. v> v comparator 108 to be a ₂ sends an ON signal to the AND circuit 114 opens the gate of the AND circuit 114. On the other hand, the battery voltage V
It enters the circuit 112 under control. This circuit 112 outputs to the electromagnetic valve 44 a rectangular wave current whose pulse width is controlled so that the duty ratio changes according to the voltage V. That is, when the voltage V is low, the duty ratio of the circuit 114 increases and the average opening θ
And when the voltage V is high, the opening degree θ is reduced.

The solenoid valve 45 restricts the fuel flow rate at low speed to prevent the gas concentration from becoming excessively high. That is, since the solenoid valve 44 increases the gas flow rate when the engine speed decreases, the maximum gas flow rate is reached when the engine is started, and the startability is deteriorated. The solenoid valve 45 restricts the gas flow rate until the engine speed reaches a constant to keep the mixture concentration at an appropriate level.

The engine starts and the speed increases and the starter switch 74
When the glow current is turned off, the glow current decreases
thereafter become a g ₂ engine continues to flow until it stops. During operation, the battery voltage V fluctuates due to the load fluctuation, so that the current of the solenoid valve 44 changes, and the opening degree θ changes to limit the gas flow rate according to the load.

In the above embodiment, the glow current is continuously increased while the starter switch 74 is on, but the present invention may be controlled by another method. For example, a method of increasing the glow current for a fixed time set by a timer at the time of starting the engine or a method of monitoring the engine speed and increasing the glow current to a certain speed or less can be used.

In addition, the voltage of the battery 24, which is the power supply of the glow current, greatly varies depending on the load, so that the glow current is greatly affected by the load. Therefore, the glow current may be pulse width controlled so that the battery voltage is monitored and the power of the glow plug is always substantially constant.

In the above embodiment, the engine speed is detected by the pulse generator 102, but may be detected by the battery voltage or the voltage of the generator 12.

Furthermore, in this embodiment, the intake pipe 10c has no throttle valve, and the intake air amount is not controlled. Since an engine using this kind of gas as a fuel has a feature that the combustible concentration range of the air-fuel mixture is much wider than that of an engine using ordinary gasoline or light oil, a throttle valve is provided in the intake pipe 10c as in this embodiment. Even if the control is performed only by the gas flow rate without providing, no inconvenience occurs.

(Effect of the Invention) As described above, since the present invention continuously supplies a glow current, it can be used for a gas engine using a gas other than alcohol as a fuel. In addition, since the glow current is reduced after the start of the engine in which the combustion heat increases, the life of the glow plug can be extended without overheating, and the ignition is excessively premature due to the overheating of the glow (premature ignition). There is no inconvenience of becoming unstable. Further, this gas engine can maintain a substantially constant engine rotation by controlling the gas supply amount by an electromagnetic valve, and can also be a simple power generator because the generator is also used as a starter motor.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram of one embodiment of the present invention, FIG. 2 is a system diagram of an engine generator using this embodiment, FIG. 3 is a layout diagram of each part thereof, and FIG. 4 is a control block of a solenoid valve. FIG. 5 is an output waveform diagram of each part, and FIG. 6 is a glow control circuit diagram. 10 ... Gas engine, 10f ... Glow plug, 12 ... Generator combined with starter, 36 ... Gas cylinder, 44 ... Solenoid valve, 72 ... Operation switch, 74 ... Starter switch, "100 ... Engine rotation Detecting means, 120: glow control circuit.

────────────────────────────────────────────────── (5) References JP-A-56-18068 (JP, A) JP-A-56-126764 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) F02P 19/00-19/02

Claims (1)

(57) [Claims] 1. A gas engine power generator for driving a generator also serving as a starter motor by a glow ignition gas engine using gas as fuel and ignited by a glow plug, comprising: an operation switch which is kept on during operation; A starter switch that is turned on when the engine is started, a glow control circuit that continuously supplies a small current to the glow plug during the ON period of the operation switch, and increases a current of the glow plug during the ON period of the starter switch; 1. A gas engine power generator comprising: an engine rotation detecting means for detecting a rotation speed of a motor; and a solenoid valve for controlling a supply amount of gas to keep the rotation speed of the engine substantially constant.