JPS621397Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a speed governing control device (means for fuel switching and engine speed governing) in a gas/diesel dual fuel engine which is constructed by adding a gas fuel supply line to the diesel engine.

Conventionally, speed governing control devices for gas/diesel dual fuel engines have generally been mechanical in their main parts using a link mechanism.

In other words, a link mechanism (fuel switching means) that uses a mechanical/hydraulic or electric/hydraulic governor as the engine speed regulating means and has multiple nodes that can serve as fulcrums.
A diesel fuel injection pump and a gas fuel amount regulating valve were each connected to the governor via a. Then, with a separately provided hydraulic cylinder,
Any node of the link mechanism is selected and fixed, and the governor output is linked only to the diesel fuel injection pump using that node as a fulcrum (at this time,
(The gas fuel amount adjustment valve is shielded), while the other node is fixed and used as a fulcrum, and the governor output is now linked only to the gas fuel amount adjustment valve (at this time, the diesel fuel injection pump's rack is The pilot injection amount was kept as locked as possible.

However, since it uses a link mechanism in this way, it has the following drawbacks.

′ Since fuel switching between the diesel side and the gas side is performed mechanically using a link mechanism, the structure is complex, requires maintenance such as refueling, and there are many moving parts, which can easily cause malfunctions. .

′ Due to the frictional force on each part of the complex link mechanism, speed control must be controlled.
The drive source, the governor, requires a large output, and generally requires an expensive hydraulic governor.

' Since friction, bumps, deformation, etc. are unavoidable in each part of the link mechanism, hunting is likely to occur during control, making it impossible to improve control accuracy.

' Since it is generally not easy to change the control constants (link dimensions, spring constants, etc.) of the link mechanism, it has not been possible to respond flexibly to changes in the gas fuel composition used.

The purpose of the present invention is to overcome the drawbacks of conventional control devices using such link mechanisms, and to develop a gas/diesel dual fuel engine that has advantages such as simple structure, easy maintenance, and fewer failure points. The purpose of the present invention is to provide a speed control device.

In order to achieve this objective, the present invention provides a PID control circuit that receives a rotational speed signal of the diesel engine and a setting signal for the same rotational speed, and an arbitrary voltage generation circuit that receives an instruction signal from the main control circuit. an electric actuator with a modulation amplifier circuit for driving a pump and an electric actuator with a modulation amplifier circuit for driving a gas fuel amount regulating valve in a gas fuel supply line added to the diesel engine;
Further, during diesel fuel operation, the output of the PID control circuit is guided to the modulation amplification circuit on the diesel fuel injection pump side, and the output from the arbitrary voltage generation circuit is set to zero volts and the output is applied to the gas fuel amount adjustment valve side. Also, during gas fuel operation, the output of the PID control circuit is guided to the modulation amplifier circuit on the gas fuel amount adjustment valve side, and the output of the arbitrary voltage generation circuit is set to a voltage proportional to the pilot injection amount of diesel fuel. A mode switching circuit is provided which leads to the modulation amplification circuit on the diesel fuel injection pump side.

Hereinafter, the present invention will be specifically explained with reference to the drawings.

The figure is a schematic configuration diagram of a speed governor control device according to an embodiment of the present invention.

In the figure, 1 is a gear installed in a diesel engine (not shown) to detect the rotational speed of the engine.
2 is a rotation sensor, 3 is an F/V (frequency-voltage) converter, 4 is an engine rotation speed setting device, 5 is a PID control circuit, 6 is a main control circuit, 7 is an arbitrary voltage generation circuit, 8
is a mode switching circuit, 9, 9' is a modulation amplifier circuit, 1
0,10' are servo solenoid actuators,
11 is a diesel fuel injection pump, 12 is a gas fuel supply line added to the diesel engine (not shown), and 13 is a gas fuel amount adjustment valve. After the mode switching circuit 8, there are two lines, a diesel fuel line D and a gas fuel line G.

A First, the operation in the case of diesel fuel operation using the speed governor control device of the present invention having the above configuration will be explained.

In this case, since the gas fuel amount regulating valve 13 must be fully closed, the output of the arbitrary voltage generating circuit 7 is set to 0 [V] by the instruction signal M from the main control circuit 6, and the mode of the mode switching circuit 8 is set to connection a as shown by the solid line.
That is, by introducing a 0 [V] signal to the gas fuel line G side, the servo solenoid actuator 10' is held in a fully closed state, so that gas fuel g is not supplied to the engine.

In this state, the engine rotation speed detected by the rotation sensor 2 is converted into a voltage by the F/V converter 3, and a signal V is input to the PID control circuit 5. On the other hand, a reference voltage signal Vo proportional to a predetermined rotation speed set in advance in the engine rotation speed setting device 4 is also input to the PID control circuit 5.
Have students compare V and Vo. The output signal C controlled by the PID operation is sent to the modulation amplification circuit 9 on the diesel fuel line D side via the mode switching circuit 8.

In this modulation amplification circuit 9, pulse width modulation amplification and current limitation are performed, and then a servo solenoid actuator 10 is driven by the output signal Cm, and diesel fuel d is supplied to the engine from a fuel injection pump 11. .

The engine speed is controlled by moving the rack position of the fuel injection pump 11. That is, by changing the movement of the servo solenoid actuator 10 using the signal Cm, the easy position movement of the fuel injection pump 11 is controlled, and the circuit from the F/V converter 3 to the modulation amplifier circuit 9 Functions as an electronic governor circuit.

B Next, the operation during gas fuel operation will be explained.

In this case, the instruction signal from the main control circuit 6
By M', the output of the arbitrary voltage generation circuit 7 is made into a voltage signal V _P proportional to the pilot injection amount of diesel fuel, and the mode of the mode switching circuit 8 is made into the connection b shown by the broken line.

As a result, a certain amount of diesel fuel d required to ignite the gas fuel g in the engine can be pilot injected from the fuel injection pump 11, and the control signal C from the PID control circuit 5 can be guided to the gas fuel line G side. Accordingly, gas fuel g can be supplied to the engine.

At this time, the speed of the engine is controlled by increasing or decreasing the opening degree of the gas fuel amount regulating valve 13 by the movement of the servo solenoid actuator 10'.
The circuit up to this point functions as an electronic governor circuit.

In the present invention, the mode switching circuit 8 can be easily constituted by, for example, a minute current relay, an analog switch, or the like. The PID control circuit 5 is
It can be composed of an addition or subtraction circuit for V and Vo, a proportional/integral/differential circuit that branches off and receives the output of the addition (subtraction) circuit, and a circuit that re-adds each output of the proportional/integral/differential circuit.

As explained above, since the speed governor control device for a gas diesel secondary fuel engine of the present invention has the above configuration, it can achieve the following effects.

Fuel switching between the diesel side and the gas side is not done by mechanical means such as a link mechanism.
Since this is done electrically using a mode switching circuit, the structure is simple and maintenance is easy (no need for lubrication, etc.), and there are fewer failure points such as mechanically moving parts.

Since it does not have a link mechanism like conventional devices, there is no resistance such as frictional force of the link part, so the governor output can be small, and furthermore, it does not require the help of a hydraulic cylinder or the like.

Since no link mechanism is used, bumps and bumps in the transmission system are minimized, so the cause of hunting is suppressed and control accuracy is improved.

Control constant (output signal of engine speed setting device 4
Vo, etc.) can be easily changed, so it is possible to flexibly respond to changes in the gas fuel components used.

Since fuel switching and engine speed regulation are performed electrically, remote control is easily possible.

[Brief explanation of the drawing]

The figure is a schematic configuration diagram of a speed governor control device according to an embodiment of the present invention. 2... Rotation sensor, 3... F/V converter, 4...
...Engine speed setting device, 5...PID control circuit, 6
...Main control circuit, 7...Arbitrary voltage generation circuit, 8...
...Mode switching circuit, 9,9'...Modulation amplification circuit,
10, 10'... Servo solenoid actuator, 11... Diesel fuel injection pump, 12...
...Gas fuel supply line, 13...Gas fuel amount adjustment valve.

Claims (1)

[Scope of utility model claims] A PID control circuit that receives the rotational speed signal of the diesel engine and a setting signal for the same rotational speed and an arbitrary voltage generation circuit that receives the instruction signal from the main control circuit are provided, and a modulation amplifier circuit for driving the diesel fuel injection pump is provided. and an electric actuator with a modulation amplifier circuit for driving a gas fuel amount regulating valve in a gas fuel supply line added to the diesel engine, and when operating on diesel fuel, the PID control The output of the circuit is guided to the modulation amplification circuit on the side of the diesel fuel injection pump, and the output from the arbitrary voltage generation circuit is set to zero volts and guided to the modulation amplification circuit on the side of the gas fuel amount adjustment valve,
In addition, during gas fuel operation, the output of the PID control circuit is guided to the modulation amplifier circuit on the gas fuel amount adjustment valve side, and the output of the arbitrary voltage generation circuit is set to a voltage proportional to the pilot injection amount of diesel fuel on the diesel fuel injection pump side. A speed governor control device for a gas/diesel dual fuel engine, which is equipped with a mode switching circuit that leads to a modulation amplification circuit.