JPH04123339U - Rotational speed control device for internal combustion engine driven generator - Google Patents

Abstract

(57) [Summary] [Purpose] When performing control to keep the engine rotation speed low when the generator is not loaded, and increase the engine rotation speed to the rated value when the generator is loaded, it is possible to control the load with a large starting current. This enables the vehicle to be driven without any problems. [Structure] A timer circuit 10A is provided in the speed setting circuit 10. When the load detection signal is generated, the timer circuit 10A
When the timer circuit completes the timed operation, the magnitude of the speed setting signal is switched from a low value during no-load operation to a high value during rated operation. A deviation between a rotational speed detection signal of the internal combustion engine and a speed setting signal is detected, and the internal combustion engine is controlled so as to reduce this deviation to zero.

Description

[Detailed explanation of the idea]

0001

[Industrial application field]

This invention is a rotational speed control system that controls the rotational speed of an internal combustion engine-driven generator according to the load. This is related to the control device.

0002

[Conventional technology]

An internal combustion engine-driven generator that uses an internal combustion engine to drive the generator and supply power to the load. As shown in Utility Model Publication No. 62-6269, the rotation of the internal combustion engine is By reducing the rotation speed and lowering the output voltage of the generator, the internal combustion engine A rotation speed control device is provided to increase the rotation speed of the motor to the rated value.

0003 Conventional rotation speed control devices of this type supply fuel to the internal combustion engine according to the drive current. A fuel supply amount adjustment section that adjusts the amount of fuel supplied, and a speed detection signal that detects the rotational speed of the internal combustion engine. A speed detector that outputs a load detector that outputs a load detection signal when a predetermined load current is detected; When a load detection signal is generated using the load detector output as input, the Outputs the corresponding speed setting signal for rated operation, and outputs the speed setting signal for rated operation when no load detection signal is generated. outputs a speed setting signal for no-load operation corresponding to a rotation speed lower than the rated rotation speed. The output of the speed setting circuit, the output of the speed detection circuit, and the output of the speed setting circuit are input. A deviation detection circuit that detects the deviation between the speed detection signal and the speed setting signal, and a deviation detection circuit that reduces the deviation to zero. a manipulated variable calculation circuit that calculates the manipulated variable of the fuel supply amount adjustment section necessary for the operation; the fuel supply amount adjustment section so as to operate the fuel supply amount adjustment section by the calculated operation amount. and a drive circuit that provides a drive current.

0004 When no load detection signal is generated, the speed setting circuit The deviation detection circuit is used to output a speed setting signal for no-load operation that is suitable for low rotational speeds. The road detects the deviation between the speed detection signal and this speed signal for no-load operation. Manipulated amount calculation The circuit calculates the operating amount of the fuel supply amount adjustment section necessary to make this deviation zero, and then The dynamic circuit provides the drive necessary to operate the fuel supply amount adjustment section by the calculated amount of operation. A current is applied to the fuel supply amount adjusting section. This reduces the rotational speed of the internal combustion engine during no-load operation. It is kept at a low value suitable for transitions.

[0005] When a load detection signal is generated, the speed setting circuit sets a constant speed corresponding to the rated rotation speed. In order to output the speed setting signal for rated operation, the deviation detection circuit uses the speed detection signal and this rating. Detects the deviation from the driving speed signal. In order to reduce this deviation to zero, the manipulated variable calculation circuit The amount of operation required for the fuel supply amount adjustment section is calculated, and the drive circuit only controls the amount of operation calculated. Applying a driving current necessary for operating the fuel supply amount adjustment section to the fuel supply amount adjustment section. I can do it. As a result, the rotational speed of the internal combustion engine is maintained at the rated value.

[0006]

[Problem that the idea aims to solve]

Conventional control devices rated the engine rotational speed as soon as load application was detected. As the starting current was increased to a high value, it was When starting up, a large current flows and circuit protectors such as fuses and breakers operate. There was a problem that the product could no longer be used.

[0007] For example, if the generator is a magnet generator, the set rotation speed NL0 when the generator is under no load is The output when rotating at the set rotation speed No. during rated operation and when rotating at the set rotation speed No. An example of the characteristics of the output voltage v with respect to the output current i is shown by curves A and R in Figure 4, respectively. As shown. Also, if the load is an induction motor, the impedance at startup For example, the distance is given by a straight line Rs. In Figure 4, ip is the circuit protector is the operating current. This operating current is typically set at 150% to 200% of the rated current. The circuit protector is activated when a current equal to or higher than the operating current ip flows for a specified period of time. operates to cut off the current supplied from the generator to the load.

[0008] In conventional rotational speed control devices, the load current is detected and the engine rotational speed is controlled at the same time. The operating point of the generator was as shown in Fig. 4 because the rotation speed was increased to the rated operating speed No. At point a, the starting current is larger than the operating current ip of the circuit protector. flows. Therefore, the circuit protector operates and the load cannot be driven. There is a problem of becoming.

[0009] The purpose of this invention is to make it possible to drive loads with large starting currents without any problems. An object of the present invention is to provide a rotational speed control device for an internal combustion engine-driven generator.

0010

[Means to solve the problem]

This invention is a fuel supply amount adjustment system that adjusts the amount of fuel supplied to an internal combustion engine according to the drive current. a joint, a speed detector that detects the rotational speed of the internal combustion engine and outputs a speed detection signal; Detects the load current of a generator driven by an internal combustion engine to detect a predetermined load current. A load detector outputs a load detection signal when the load is detected, and the output of the load detector is input When the load detection signal is generated, the speed setting for rated operation corresponds to the rated rotation speed. Outputs a signal, and when the load detection signal is not generated, the rotation speed is lower than the rated speed. A speed setting circuit that outputs a speed setting signal for no-load operation corresponding to the rotation speed, and The output of the detection circuit and the output of the speed setting circuit are used as inputs to generate the speed detection signal and the speed setting signal. A deviation detection circuit that detects the deviation from the number and the amount of fuel supply required to make the deviation zero A manipulated variable calculation circuit that calculates the manipulated variable of the control section, and a fuel supply amount based on the calculated manipulated variable. Equipped with a drive circuit that applies a drive current to the fuel supply amount adjustment section to operate the adjustment section. This invention relates to a rotational speed control device for an internal combustion engine-driven generator.

[0011] In this invention, the speed setting circuit has a timer set when a load detection signal is generated. After starting the operation and during the timed operation, the speed setting signal for no-load operation continues to be output, and the timed operation continues. A timer circuit is provided to output the speed setting signal for rated operation when the operation is completed. Ta.

0012 In the above configuration, the fuel supply amount adjustment section supplies fuel to the engine according to the drive current. The amount of fuel supplied can be adjusted by operating the amount adjusting means (e.g. throttle valve). Therefore, for this fuel supply amount adjustment part, for example, a power supply using an electromagnet or an electric motor as the drive source is recommended. A device in which the fuel supply amount adjustment means is operated by a dynamic actuator is used. I can be there.

[0013]

[Effect]

As mentioned above, a timer circuit that starts timed operation when a load detection signal occurs is provided, and the speed setting signal for rated operation is sent when the timer circuit completes the timed operation. If the timer circuit is activated, the operation time limit of the timer circuit will be determined by the load current after the load starts. By setting the time approximately equal to the time required to settle down to a normal state, the Even if the load has a large current, it can be started without operating the circuit protector. can do.

[0014]

【Example】

Figure 1 shows the overall configuration of an embodiment of the present invention, in which 1 is an internal combustion engine. This is a generator driven by engine 2. In this example, this generator is the engine output Assume that it is a magnet generator with a rotor attached to the shaft. 3 is driven by generator 1 When the load current exceeds a predetermined value between the output terminal of generator 1 and load 3, A circuit pro that operates to cut off the load current when it continues to flow for a predetermined period of time or more. Tector 4 is inserted. Circuit protector 4 includes breakers and fuses. etc. are used.

[0015] Reference numeral 5 denotes a fuel supply amount adjustment section that operates using the battery 6 as a power source. For example, an electric actuator that drives the operating shaft of an engine's throttle valve. Ru.

[0016] 7 is a speed detector that outputs a signal with a frequency proportional to the rotational speed of the engine, 8 is a speed The frequency of the output signal of the detector 7 is converted into a voltage signal to generate a speed proportional to the rotational speed of the engine. A speed detection circuit that outputs a speed detection signal Vn, which is connected to speed detector 7 and speed detection circuit 8. A speed detector is constructed. The speed detector is proportional to the engine rotation speed. The configuration is arbitrary as long as it outputs a speed detection signal.

[0017] 9 detects the load current of a generator driven by an internal combustion engine and sets a predetermined load current. A load detector that outputs a load detection signal VL when detected. The speed setting circuit consists of a timer circuit 10A and a speed setting signal output circuit 10B. It is given to 10.

[0018] The speed setting signal output circuit 10B outputs a speed setting signal Vno for rated operation and a speed setting signal for no-load operation. It is designed to be able to output the speed setting signal VnL0 and the output of the timer circuit 10A. When the power is in the first state, the speed setting signal VnL0 for no-load operation is output, and the timer When the output of circuit 10A changes to the second state, the rated operation speed setting signal Vno is It is designed to be output.

[0019] The timer circuit 10A starts timed operation when the load detection signal VL is generated. The output of this timer circuit is the state before starting timed operation and during timed operation. The first state is maintained and the second state is entered when the timed operation is completed.

[0020] Therefore, after starting the engine and with no load applied, the speed setting circuit outputs the speed setting signal VnL0 for no-load operation, and at a predetermined delay after the load is applied. When the time has elapsed, the speed setting circuit outputs the speed setting signal Vno for rated operation.

[0021] The speed detection signal Vn and speed setting signals Vno and VnL0 are input to the deviation detection circuit 11. It will be done. The deviation detection circuit 11 calculates the difference between the speed detection signal Vn and the speed setting signal, A deviation signal Vd (=Vn - Vno or Vn - VnL0) is output.

[0022] The output Vd of the deviation detection circuit 11 is given to the manipulated variable calculation circuit 12. Arithmetic circuit 12 calculates the operating amount of the fuel supply amount adjusting section 5 necessary to make the deviation signal Vd zero. and provides the drive circuit 13 with an operation signal Vb that provides the calculated operation amount. driving times The line 13 adjusts the fuel supply amount adjusting section 5 so as to operate the fuel supply amount adjusting section 5 by the calculated operation amount. A drive current is applied to section 5. The drive circuit 13 is usually a switching element such as a transistor. It consists of a switch circuit using a switch, which conducts when an operation signal is applied to supply fuel. A predetermined drive current is applied to the feed amount adjustment section. This keeps the engine speed at the set speed. dripping When no load detection signal is generated, the speed setting circuit 10 performs no-load operation. Since the diversion speed setting signal VnL0 is output, the engine rotation speed is kept at a low level suitable for no-load conditions. The rotation speed is maintained at a high rotation speed. When a load is applied, a load detection signal is generated, so the tie The timer circuit starts the timed operation, and the speed is set when the timer circuit completes the timed operation. The circuit outputs the speed setting signal Vno for rated operation. Therefore, the rotational speed of the engine is The rotation speed is increased to a high rotation speed suitable for rotation, and while the load is applied, the rotation speed is increased to a high rotation speed suitable for rotation. Speed is maintained.

[0023] Now, when the rotational speeds during rated operation and no-load operation are respectively No and NL0. Assume that the output characteristics of the generator are as shown in Figure 4, and that the generator has an initial Assuming that an induction motor whose impedance is represented by a straight line Rs is connected, the device of the present invention If the engine speed is Since the temperature is maintained at NLo, the operating point when starting the generator is point b as shown in the diagram. The load current has a lower iso than the operating current ip of the circuit protector. Therefore The motor can be started without operating the circuit protector. . In this case, the current iso that can flow through the motor at the rotation speed during no-load operation is , use a generator of sufficient capacity to start the motor. Of course it is necessary. As the rotational speed of the electric motor increases, The slope of the impedance line increases, and the armature current decreases. I'm going to go. The motor has almost finished starting and the armature current reaches the circuit when the rated voltage is applied. When the operating current ip of the protector falls below the speed setting signal, the speed setting signal is By switching to the diversion speed setting signal, it is possible to shift to rated operation without any problems. .

[0024] FIG. 2 shows a specific example of the configuration of the speed setting circuit 10. In this example, load 3 is Connected between the output terminals of the generator 1 via the switch SW and the circuit protector 4. It is continued. The load detector 9 consists of a current transformer CT, and the output of this load detector is input to the timer circuit 10A. The timer circuit 10A functions as a time-limiting element. capacitor C1, resistor R1 to R8, diodes D1 and D2, and load test Capacitor C2 for smoothing the output signal, transistor TR1, and voltage comparator It consists of CP1.

[0025] In this timer circuit, when the load detector 9 is not detecting the load current, , since the transistor TR1 is in the cut-off state, the capacitor C1 is connected to a direct current (not shown). It is charged with the polarity shown in the figure by the voltage Vcc of the power supply. At this time, the capacitor C1 Since the terminal voltage Vc is higher than the reference voltage Vref obtained across the resistor R7, the comparison The output terminal of device CP1 is almost at ground potential (the output of the comparator is in the first state) . When the switch SW is closed and the load 3 is turned on, the load detector 9 outputs a load detection signal. To generate a signal, transistor TR1 becomes conductive. Transistor TR1 conducts Then, the charge of capacitor C1 is transferred to resistor R4 and the collector emitter of transistor TR1. The terminal voltage of capacitor C1 decreases as it discharges at a constant time constant through the capacitor C1. I will do it. The set time (timer operation time limit) has elapsed since the load detection signal was generated. Then, the terminal voltage of capacitor C1 becomes lower than the reference voltage Vref, so the comparator The potential of the output terminal of CP1 becomes high level (the output of the comparator becomes the second state) . When the load detection signal disappears, the transistor TR1 is cut off, so the capacitor C1 is being charged through resistor R5. Predetermined time after the load detection signal disappears When the terminal voltage Vc of capacitor C1 exceeds the reference voltage Vref after The potential of the output terminal of CP1 becomes the ground potential again.

[0026] The speed setting signal output circuit 10B includes a voltage dividing circuit consisting of resistors R10 to R12, and a voltage dividing circuit consisting of resistors R10 to R12. Operational amplifier OP installed between the connection point of resistors R10 and R11 of the pressure circuit and the output terminal 1, and a voltage follower circuit consisting of The output terminal of the comparator of the timer circuit 10A is connected.

[0027] When the potential of the output terminal of the comparator of the timer circuit is at ground level (load detection signal (when the timer circuit is not occurring or when the timer circuit is performing time-limited operation), the resistance is Since the potential at the connection point of resistors R11 and R12 becomes ground potential, the input voltage of the voltage follower circuit The voltage is the value obtained by dividing the power supply voltage Vcc by resistors R10 and R11, and at this time the speed setting The constant circuit 10 is a speed setting signal for no-load operation VnL0 = Vcc・R11/(R10+R11) Output. After the load detection signal is generated, the timer circuit 10A completes the dimensional operation. When this occurs, the potential at the output terminal of comparator CP1 becomes high level, so The voltage across resistors R11 and R12 is input to the circuit. At this time, the speed setting circuit Speed setting signal for rated operation Vno={Vcc (R11+R12)/(R10+R11+R12)} >Output VnL0.

[0028] Figure 3 shows the speed settings when the load 3 of the generator is turned on and off in the above embodiment. The speed setting signal obtained from the constant circuit 10 is shown. After a certain delay time Ton has elapsed after the output signal is generated, the speed setting signal for rated operation is After the load detection signal disappears, a certain delay time Toff has elapsed. After that, the speed setting signal for no-load operation is switched to VnL0.

[0029] In the embodiment shown in FIG. 2, the resistance value of resistor R4 may be adjusted; Alternatively, if the resistance value can be switched, the rated operation can be adjusted according to the load characteristics. You can adjust the delay time during migration.

[0030]

[Effect of the idea]

As described above, according to the present invention, when the load detection signal is generated, the rated operating speed is The generation of the temperature setting signal is delayed by a predetermined period of time to limit the load starting current. This has the advantage of being able to drive loads with a large starting current without any problems.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention.

FIG. 2 is a circuit diagram showing a specific example of the configuration of the speed setting circuit of the embodiment in FIG. 1;

FIG. 3 is a diagram showing changes in a speed setting signal when a load is turned on and off in the embodiment of the present invention.

FIG. 4 is a diagram showing an example of output characteristics of a generator.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1... Generator, 2... Internal combustion engine, 3... Load, 4... Circuit protector, 5... Fuel supply amount adjustment part, 6... Battery, 7
…Speed detector, 8…Speed detection circuit, 9…Load detector, 1
0... Speed setting circuit, 11... Deviation detection circuit, 12... Manipulated amount calculation circuit, 13... Drive circuit.

Claims (1)

[Scope of utility model registration request] 1. A fuel supply amount adjusting section that adjusts the amount of fuel supplied to the internal combustion engine in accordance with a drive current, a speed detector that detects the rotational speed of the internal combustion engine and outputs a speed detection signal, and the internal combustion engine. a load detector that detects the load current of a generator driven by the generator and outputs a load detection signal when a predetermined load current is detected; and a load detection signal is generated using the output of the load detector as input. At times, a speed setting signal for rated operation corresponding to the rated rotational speed is output, and when the load detection signal is not generated, a speed setting signal for no-load operation corresponding to a rotational speed lower than the rated rotational speed is outputted. a speed setting circuit, a deviation detection circuit that receives the output of the speed detection circuit and the output of the speed setting circuit as inputs and detects a deviation between the speed detection signal and the speed setting signal; A manipulated variable calculation circuit that calculates the manipulated variable of the fuel supply amount adjustment section, and a drive circuit that applies a drive current to the fuel supply amount adjustment section so as to operate the fuel supply amount adjustment section by the calculated operation amount. In the rotational speed control device for an internal combustion engine driven generator, the speed setting circuit comprises:
A timer circuit that starts a timed operation when the load detection signal is generated, continues to output the speed setting signal for no-load operation during the timed operation, and outputs the speed setting signal for rated operation when the timed operation is completed. A rotation speed control device for an internal combustion engine-driven generator, comprising: