JPH08312506A - Starting control device of engine working machine - Google Patents

Abstract

PURPOSE: To certainly start an engine, to reduce deterioration and failure of a drive motor of a starting device and to prevent malfunction of a control device of a working machine. CONSTITUTION: A working machine is connected to an engine, and a starting device 3 is constituted free to connect. At the time when engine speed of the engine is higher than a standard value of a standard value setting means 22, an engine speed rising information signal is output from a comparator 24. When output of this engine speed rising information signal continues for longer than specified time T, the engine speed rising information signal is output from a timer 26 to a starting stop means 29 and a starting information means 30, the starting device 3 is controlled in a stop state as a starting stop signal is output from the starting stop means 29, and a working machine is controlled in a stop state as a starting information signal is output from the starting information means 30. Additionally, as the standard value of the standard value setting means 22 is lowered in accordance with the engine speed rising information signal, output of the engine speed rising information signal of the comparator 24 is held as long as the engine does not stop.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine start control device, and more particularly to an improvement of a start control device for controlling an engine start device to which a working machine is connected.

[0002]

There is an engine working machine in which an engine is connected to a compressor of an air machine or a hydraulic pump of a hydraulic machine in order to drive a working machine such as an air machine or a hydraulic machine used for civil engineering. In this type of engine work machine,
The engine is started by a starter composed of a drive motor. That is, when the key switch is manually turned from the off position to the starter position, the pinion gear connected to the drive motor meshes with the ring gear connected to the crankshaft of the engine. Then, the drive motor is driven to rotate the pinion gear, so that the engine is started via the ring gear. Thereafter, when the key switch is manually operated to return from the starter position to the on position, the operating device is stopped.

By the way, if the actuating device is stopped by manually operating the key switch, the drive motor is driven even though the start of the engine is completed, so that an excessive current flows in the drive motor and the battery is discharged. However, the drive motor may excessively rotate when the engine is started, resulting in deterioration or failure of the drive motor. Further, if the key switch is mistakenly turned to the starter position after the start of the engine is completed, there is a possibility that the starter operates and the pinion gear hits the rotating ring gear, causing a ringing noise or damaging the pinion gear or the ring gear.

[0004]

Therefore, in the conventional engine working machine,
The starting control device detects the rotation speed of the engine to determine the completion of the engine start, and after the completion of the engine start, the starting device is stopped even if the key switch is in the starter position. That is, in the conventional start control device, the completion of the start of the engine is determined by detecting the rotation speed of the engine by each of the following methods. That is, the power generation voltage of the alternator or dynamo whose voltage rises corresponding to the increase of the rotation speed of the engine is measured. Then, when the voltage generated by the alternator or the like becomes equal to or higher than a preset voltage (reference value), it is determined that the engine has been started.

As another method, a photo sensor is provided facing the ring gear of the engine. Then, the gear teeth of the ring gear that passes through the detection area of the photo sensor as the engine rotates are converted into pulse signals and measured, and this pulse is the preset number of pulses per unit time.
It is judged that the engine has been started when the value exceeds the (reference value). By the way, when a cold engine is started by stopping the engine for a long time, for example, the rotation speed of the engine rises and reaches a peak immediately after the engine is driven by the starter, as shown in FIG. There is a case where the engine starts to descend before the completion of the start of the engine, then rises again, and then the engine start is completed.

[0006]

SUMMARY OF THE INVENTION In the above-mentioned conventional start control device, it is erroneously determined that the engine start has been completed at the engine rotation speed increased immediately after the start of driving the engine, and the actuator is activated before the engine start is completed. May stop. Further, the engine speed fluctuates in small steps due to the intermittent combustion of the engine. For this reason, the power generation voltage of the alternator and the number of pulses from the photo sensor also fluctuate little by little with this small variation, and as shown in FIG. 3, the engine speed is the reference value (800 rp in FIG. 3).
After m) or more, so-called chattering occurs, which is less than or equal to the reference value in a short time.

Due to this chattering, the starter repeatedly operates and stops in small increments, and a rush current repeatedly flows to the drive motor of the starter in a short time, and the rush current compares the drive motor for deterioration or failure. May be invited in a very short period of time. Further, in the above-mentioned start control device, a start notification signal is sent to the control device of the work machine at the time of completion of the start of the engine, and the work machine starts operation after receiving the start notification signal. Due to small fluctuations in the voltage and the number of pulses from the photo sensor,
The start notification signal may be sent in small increments, which may cause the working machine to malfunction.

On the other hand, the engine may be restarted before the engine cools after the key switch is returned to the off position to stop the engine. At this time, since the lubricating oil is still prevailing in the engine, the rotation speed of the engine rises to high-speed rotation in a short time, and the engine finishes starting in a short time. At this time, stopping the starting device in a short time can prevent wasteful current consumption after the engine is started. In addition, when the engine is in a no-load state due to improper mounting of the work machine to the engine, or when the work machine is overloaded, the engine speed is increased to a high speed and then the engine is stopped.

In this case, the engine is repeatedly stopped even if the working machine is properly mounted on the engine or the starting device is operated until the excessive load is released, and the drive motor is driven by the increase of the engine to high speed rotation. Is rotated at a high speed, which may cause deterioration or failure of the drive motor in a relatively short period of time. It is an object of the present invention to reduce deterioration and failure of a drive motor of a starter device while reliably starting an engine and to prevent malfunction of a control device for a working machine.

[0010]

[Means for Solving the Problems]

(First Invention) In order to achieve the above object, the first invention is
For example, as shown in FIG. 1, a working machine 2 is drivably connected to an engine 1 and a starting device 3 for starting the engine is provided.
Is provided so as to be connectable, and a rotation speed detection means 11 for detecting the rotation speed of the engine 1 and a control means 4 having a comparator 24 are provided, and the rotation speed detection means 11 and the reference value setting means 22 are provided at the comparison input of the comparator 24. And the output of the comparator 24 are connected to the inputs of the start / stop means 29 and the start notification means 30, respectively, and the rotation speed of the engine 1 is equal to or higher than the reference value preset by the reference value setting means 22. In this case, the comparator 24 outputs the rotation increase notification signal to the start stop means 29 and the start notification means 30, and the start stop means 29 outputs the start stop signal in response to the rotation increase notification signal from the comparator 24. In addition to being output, a start notification signal is output from the start notification means 30, and the start stop means 29 starts and stops. When the signal is output, the starting device 3 is controlled to a stopped state, and when the activation notification signal is output from the activation notification means 30, the working machine 2 is controlled to be in an operable state. The starting control device of No. 1 is characterized by being configured as follows.

That is, the timer 26 is interposed between the output of the comparator 24 and the inputs of the start / stop means 29 and the start notification means 30, and the output of the timer 26 is connected to the reference value switching means 27 to switch the reference value. The output of the means 27 is connected to the reference value setting means 22 so that the rotation increase notification signal is output from the timer 26 when the rotation increase notification signal from the comparator 24 continues for a predetermined time T1 or longer, and the reference value is switched. The means 27 is configured to lower the reference value of the reference value setting means 22 in response to the rotation increase notification signal from the timer 26.

(Second invention) In the second invention, the control means 4 has the second reference value setting means 23, the second comparator 25, and the holding means 28 in the first invention, and the second reference value setting is performed. The means 23 is preset to a second reference value that is larger than the first reference value of the first reference value setting means 22, and the rotation speed detecting means 11 and the second reference value setting means 23 are provided to the comparison input of the second comparator 25. Of the second comparator 25, and the output of the second comparator 25 is connected to the input of the start / stop means 29 via the holding means 28. When the rotation speed of the engine 1 is equal to or higher than the second reference value, the second comparator 25 is connected. From the second comparator 25 to the start / stop means 29, and the second rotation increase notification signal is output to the holding means 28. Those that are configured to hold the output of the rising broadcast signal.

[0013]

[Action]

(First Invention) In the first invention, for example, as shown in FIG. 2, it operates as follows. For example, when the engine 1 that has cooled down is started by stopping the engine for a long time and the starting of the starting device 3 is started, immediately after the starting of the starting device 3 (at time t0), the rotation speed of the engine 1 is low and The rotation speed of the engine 1 detected by the speed detection means 11 becomes smaller than the reference value of the reference value setting means 22. Therefore, the rotation increase notification signal is not output from the comparator 24, and accordingly, the rotation increase notification signal is not output from the timer 26. Therefore, the start stop signal is not output from the start stop unit 29, the starter 3 continues to operate, the start notification signal is not output from the start notification unit 30, and the work machine 2 does not start operating.

After that, when the rotation speed of the engine 1 increases with the operation of the starting device 3 and the rotation speed of the engine 1 becomes equal to or higher than the reference value of the reference value setting means 22 (time t1), the rotation speed is increased from the comparator 24. Although the notification signal is output, before the set time T1 of the timer 26 elapses, the rotation speed of the engine 1 starts to decrease and becomes smaller than the reference value (t2
Time point). Therefore, the rotation increase notification signal is not output from the timer 26. Therefore, the start stop signal is not continuously output from the start stop means 29, and the start notification signal is not output from the start notification means 30.

Then, the rotation speed of the engine 1 starts to rise again and becomes equal to or higher than the reference value (at time t3), and the state in which the rotation speed of the engine 1 becomes equal to or higher than the reference value is the timer 26.
When the set time T1 is exceeded (at time t4), the start of the engine 1 is completed at this time, and the timer 26 outputs the rotation increase notification signal. As a result, a start stop signal is output from the start stop means 29, and the start device 3
Is stopped and the drive of the engine 1 is stopped. In addition, a start notification signal is output from the start notification means 30 and the work machine 2
The operation of can be started. The rotation speed of the engine 1 fluctuates little by little due to the intermittent combustion of the engine 1,
As shown in FIG. 3, so-called chattering, which rises and falls in a short period of time with respect to the reference value, occurs, but this chattering period Tc is shorter than the set time T1 of the timer 26, and the output of the timer 26 increases in rotation in the chattering. No notification signal is output.

On the other hand, the reference value switching means 27 operates the reference value setting means 22 in response to the rotation increase notification signal from the timer 26.
By switching and lowering the reference value of, even after the start of the engine 1 is completed, the load of the work machine 2 is increased and the rotation speed of the engine 1 is decreased (at time t5) Unless it becomes smaller than the reference value, the output of the rotation increase notification signal from the comparator 24 is held and the output of the start / stop signal from the start / stop means 29 is maintained, whereby the starter 3 does not operate.
Further, the output of the start notification signal from the start notification means 30 is also maintained, and the working machine 2 is maintained in a continuously operable state without interruption.

When the rotation speed of the engine 1 becomes smaller than the reference value after the switching due to the stop of the engine 1 or the like, the output of the rotation increase notification signal from the comparator 24 is stopped, and the timer 26 outputs. The output of the rotation increase notification signal is stopped. As a result, the starting and stopping means 29
And the start notification means 30 is reset, the starter 3 returns to the operable state, and the working machine 2 returns to the operation stop state.

(Second Invention) In addition to the operation of the first invention described above, the second invention operates as follows. That is, for example, as shown in FIG. 4, when the operation of the starting device 3 is started after the engine 1 is stopped and before the engine 1 is cooled (at time t10), immediately after this operation, the rotation of the engine 1 is performed as described above. The speed is smaller than both the first reference value of the first reference value setting means 22 and the second reference value of the second reference value setting means 23. Therefore, the rotation increase notification signal is not output from the comparators 24 and 25, the starting device 3 continues to operate, and the working machine 2 does not start operating.

On the other hand, since the engine 1 has been sufficiently lubricated with the lubricating oil by the previous operation of the engine 1, the rotation speed of the engine 1 sharply rises, and the engine speed is shorter than the set time T1 of the timer 26. The rotation speed of 1 exceeds the first reference value of the first reference value setting means 22 and becomes equal to or higher than the second reference value of the second reference value setting means 23 (time t11). Then
A second rotation increase notification signal is output from the second comparator 25 via the holding means 28, and a start stop signal is output from the start stop means 29, the starter 3 is stopped, and the drive of the engine 1 is stopped. Since the output of the second rotation increase notification signal is held by the holding means 28, the stopped state of the starting device 3 is held unless the holding means 28 is reset.

[0020]

【The invention's effect】

(First Invention) The first invention has the following effects because it is configured and operates as described above. For example, when a cold engine is started by stopping the engine for a long period of time, the rotation speed of the engine rises and reaches a peak immediately after the engine is started by the starter, and then decreases before the start of the engine is completed. In some cases, the engine may start after the engine has turned around and then rises again. Even in this case, if the period during which the engine speed is equal to or higher than the reference value of the reference value setting means does not exceed the time set by the timer, the rotation increase notification signal is not output from the timer and the start / stop signal is output from the start / stop means. Since the output is not output, it is possible to accurately determine the completion of the engine start without erroneously determining that the increase in the rotation speed of the engine for a short period immediately after the start of driving the engine is the completion of the engine start. Therefore, it is possible to accurately determine the stop timing of the starting device and reliably prevent the engine starting mistake.

Further, since the reference value of the reference value setting means is lowered according to the output of the rotation increase notification signal from the timer,
After the start of the engine is completed, even if the load on the work equipment temporarily increases and the engine rotation speed decreases, the engine rotation speed will be lower than the reference value switched to the above low value such as the engine stop. Unless it becomes small, the output of the rotation increase notification signal is held. Therefore, the output of the activation informing signal from the activation informing means is maintained, and the working machine is kept in the operable state without interruption. As a result, the working machine can be operated stably without being affected by the load fluctuation.

Further, since the timer can prevent repeated start / stop of the starting device due to small fluctuations in the engine rotation speed due to intermittent combustion of the engine, the rush current to the drive motor of the starting device can be reduced in a short time. It is possible to prevent deterioration or failure of the drive motor in a relatively short period of time by repeating the flow. In addition, since the start notification signal is not output from the start notification means unless the rotation increase notification signal is output from the timer, it is possible to prevent the start notification signal from being sent to the work machine in small increments and to cause the work machine to malfunction.

(Second Invention) The second invention has the following effects in addition to the effects of the first invention. For example, when the engine is stopped and then restarted before the engine cools down, the rotation speed of the engine rapidly increases immediately after the engine is started to be driven by the starter, and the rotation speed becomes high in a short time. In this case, if the second reference value of the second reference value setting means is equal to or more than the second reference value,
The second rotation increase notification signal is output from the second comparator and the starter stops. That is, when the engine is started before it cools down, the rotation speed of the engine becomes high-speed in a short time to complete the start of the engine. However, when the rotation speed of the engine becomes equal to or higher than the second reference value, the starting device is immediately started. Since it is stopped, it is possible to prevent the capacity of the battery from being wastefully consumed, and to prevent the drive motor from rotating at high speed due to the increase in engine speed to reduce the deterioration and failure of the drive motor.

Further, since the output of the second rotation increase notification signal of the second comparator is held by the holding means, unless the holding means is reset by turning off the power source by turning off the key switch, for example, the starter is in the stopped state. Is retained. In other words, in the state where the engine does not start due to improper mounting of the work machine to the engine or excessive load on the work machine,
The engine will not start even if the engine is repeatedly driven by the starter, and the drive motor may deteriorate or malfunction due to repeated high-speed rotation of the drive motor due to the rise to high-speed rotation immediately after the engine is driven. There is. On the other hand, when the second rotation increase notification signal is output as described above, the stop state of the starter is held unless the holding means is reset, so that the drive motor deteriorates due to repeated high-speed rotation of the drive motor. It is possible to reliably prevent the above-mentioned troubles and breakdowns, and by maintaining the stopped state of the starting device, it is possible to prompt the operator to release the above-mentioned mounting failure of the working machine or the excessive load of the working machine.

[0025]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. First, the configuration of an engine working machine to which an embodiment of the starting control device of the present invention is applied will be described with reference to FIG. FIG. 1A is an overall schematic configuration diagram of the engine working machine, and FIG. 1B is a circuit diagram of the start control device.

This engine working machine has a working machine 2 connected to an engine 1 as shown in FIG.
A starting device 3 can be connected to the engine 1. Further, the engine work machine is provided with a start control device (control means) 4
The starting control device 4 is configured to control driving / stopping of the starting device 3 and activation of the working machine 2 via the working control device 7.

A ring gear 10 is interlockingly connected to a crankshaft (not shown) of the engine 1, and a rotational speed detecting means 11 composed of a photo sensor or a magnetic sensor is provided so as to face the gear teeth of the ring gear 10. It is provided. Further, the working machine 2, the starting device 3, the starting control device 4, the working control device 7, and the like are connected to a battery 6 via a key switch 5 and are supplied with power, and the battery 6 is an engine. It is connected to the alternator (or dynamo) 8 connected to 1 and charged.

Next, each part of the working machine 2 and the starting device 3 will be described in detail. An air machine including a compressor, a hydraulic machine including a hydraulic pump, or the like is applied to the working machine 2, and the operation of the solenoid valve of the working machine 2 is controlled by the work control device 7. The starting device 3 includes a drive motor 13 such as a DC motor, a magnet switch 14, a pinion gear 15, and the like.

Then, the starting device 3 drives the magnet switch 14 to push out the pinion gear 15 connected to the drive motor 13 to the ring gear 10 side and mesh with the ring gear 10 (see the chain double-dashed line diagram in FIG. 1). By driving the drive motor 13 to rotate the pinion gear 15, the ring gear 10 is rotationally driven. As a result, the crankshaft of the engine 1 is rotationally driven. When the gear teeth of the ring gear 10 cross the detection area of the rotation speed detection means 11 as the engine 1 is driven, the rotation speed detection means 11 detects the gear teeth of the ring gear 10 and converts them into pulse signals. , And outputs this pulse signal to the start control device 4.

The key switch 5 has a contact piece 16, and by inserting a key (not shown) and manually turning the contact piece 16, the contact piece 16 can be turned off, on, and started. It is possible to switch to. When the contact piece 16 is switched from the off position to the on position (the position indicated by the chain double-dashed line in FIG. 1), the battery 6 and the AC contact 51 are connected via the contact piece 16 and the battery 6 is started. Power is supplied to the control device 4 and the work control device 7.

When the contact piece 16 is switched from the ON position to the starter position (the position shown by the solid line in FIG. 1), the battery 6 is connected to the AC contact 51 and the starter contact 52 via the contact piece 16. Then, in addition to the power supply from the battery 6 to the start control device 4 and the work control device 7, the power is supplied to the start device 3 via the relay contact S1 of the relay L1 described later. The key switch 5
When the key is released, the contact piece 16 is automatically returned from the starter position to the on position by the action of a spring (not shown) or the like. When the contact piece 16 is set to the off position (not shown), the battery 6 is not connected to either the AC contact 51 or the starter contact 52.

As shown in FIG. 1B, the start control device 4 is constructed and connected as follows. This start control device 4 outputs the output of the above-mentioned rotation speed detecting means 11 [FIG. 1 (A)] through a filter section 20 and an FV converting section 21 to one input terminal (comparative input) of comparators 24 and 25. )-Are connected respectively. The other input terminal + of the comparator (first comparator) 24 has a low speed reference value setting means.
The output of (first reference value setting means) 22 is connected, and the other input terminal of the comparator (second comparator) 25 +
The output of the high-speed reference value setting means (second reference value setting means) 23 is connected to.

The output terminal of the comparator 24 is connected to the inputs of the start / stop means 29 and the start notification means 30 via the timer 26 and the input of the reference value switching means 27. The output terminal of the comparator 25 is connected to the input of the start / stop means 29 via the holding means 28. Next, details of each part of the start control device 4 will be described. The FV conversion unit 21 includes the rotation speed detection unit 1 from which noise has been removed by the filter unit 20.
The pulse signal from 1 is converted into a voltage corresponding to the pulse frequency, and the input terminal of the comparators 24 and 25-
Respectively.

The low speed reference value setting means 22 comprises voltage dividing resistors R1 and R2, a resistor R3, and a Zener diode D1. The Zener voltage of the Zener diode D1 is divided by the voltage dividing resistors R1 and R2 to generate a first voltage. The reference voltage value is output to the other input terminal + of the comparator 24. The supply voltage + B from the battery 6 is applied to the cathode of the Zener diode D1 via the resistor R3 and the key switch 5 [FIG. 1 (A)] described above.

The high-speed reference value setting means 23 is composed of voltage dividing resistors R4 and R5. The voltage dividing resistors R4 and R5 divide the zener voltage of the zener diode D1 to obtain the second reference voltage value from the other side of the comparator 25. Output to the input terminal + of. The first reference voltage value and the second reference voltage value are adjusted to the voltage values output from the FV conversion unit 21 when the engine 1 has a predetermined rotation speed. For example, the rotation speed corresponding to the first reference voltage value is 60
The rotation speed is appropriately selected from the range of 0 rpm to 800 rpm, and the rotation speed corresponding to the second reference voltage value is the first rotation speed.
A value higher than the reference voltage value and 800 rpm to 100
It is appropriately selected from the range of the rotation speed of 0 rpm.

The comparators 24 and 25 are each of a contact output type such as an open collector,
The comparator 24 uses the FV converter 21 for the input terminal −.
When the output voltage of is above the first reference voltage value, the output becomes low level (rotation increase notification signal). The comparator 25 becomes a low level (second rotation increase notification signal) when the output voltage of the FV converter 21 input to the input terminal − is equal to or higher than the second reference voltage value of the input terminal +. The comparators 24 and 25 may be voltage output type.

The input of the timer 26 is the base resistance R1.
4 and a transistor Q6, the output of the comparator 24 is connected to the output of the comparator 24. When the low level state of the output of the comparator 24 continues for a preset time T1 or more, a high level voltage is output and this output is output. It is configured to hold a voltage. Also, the timer 26
When the output voltage of the FV converter 21 becomes less than the first reference voltage value, the output of the comparator 24 returns to the high level, and when this high level state continues for a preset time T2 or more, the output voltage becomes high. Configured to return from level to low level.

The reference value switching means 27 has an input resistor R6.
And a high-level voltage is output from the timer 26, the high-level voltage is received by the base of the transistor Q1 via the input resistor R6 to turn on the transistor Q1. Then, when the transistor Q1 is turned on, the input terminal + of the comparator 24 is grounded, and the first reference voltage value to the input terminal + drops to almost 0V. That is, the first reference voltage value is changed to the output voltage value of the FV converter 21 when the rotation speed of the engine 1 is approximately 0 rpm.

The input terminal + of the comparator 24 and
A resistor is connected between the collector of the transistor Q1 and when the transistor Q1 is turned on, the first reference voltage value and the rotational speed of the engine 1 are, for example, F− when the rotation speed is 100 rpm.
The output voltage value of the V conversion unit 21 may be changed. The holding means 28 has base resistors R7 and R8.
And a supply voltage + B of the battery 6 is applied to the emitter of the transistor Q2 via the key switch 5 [FIG. 1 (A)]. Then, when the output of the comparator 25 becomes low level, a current flows from the base of the transistor Q2 to the comparator 25 through the base resistor R7 and the transistor Q2 is turned on.

Then, the high level voltage from the transistor Q2 causes the start / stop means 29 and the start notification means 30.
And to the transistor Q3. As a result, the transistor Q3 is turned on, the base of the transistor Q2 is grounded, and the transistor Q2
Is kept on. That is, the transistor Q2
Once turned on, the on state is maintained until the key switch 5 is returned to the off position and the supply of the supply voltage + B is stopped.

The start / stop means 29 has an input resistor R9.
R10, collector resistor R11, and transistor Q4
And a relay L1, the output of the timer 26 is connected to the base of the transistor Q4 via the input resistor R9, and the output of the holding means 28 (collector of the transistor Q2) is connected to the transistor via the input resistor R10. Connected to the base of Q4. When the output voltages of the timer 26 and the holding means 28 are both at the low level, the transistor Q4 is turned off and the collector resistance R1.
The supply voltage + B of the battery 6 is supplied to the relay L1 via 1, the relay L1 is turned on, and the relay contact S1 is closed.

On the other hand, when the output voltage of at least one of the timer 26 and the holding means 28 is at the high level, the transistor Q4 turns on and the supply voltage + B to the relay L1.
Is stopped, the relay L1 is turned off, and the relay contact S1 is opened. As shown in FIG. 1 (A), the relay contact S1 is interposed between the starter contact 52 of the key switch 5 and the starting device 3, and the relay contact S1 is closed and the contact piece 16 and When the supply voltage + B of the battery 6 is supplied to the starting device 3 via the starter contact 52, the starting device 3 operates.

The start notification means 30 includes an input resistor R12.
, A collector resistor R13 and a transistor Q5, and the output of the timer 26 is connected to the base of the transistor Q5 via the input resistor R12. When the output voltage of the timer 26 is low level, the transistor Q5 is turned off and the high level voltage is output to the work control device 7. On the other hand, when the output voltage of the timer 26 is high level, the transistor Q5 is turned on and the low level voltage is output to the work control device 7 as a start notification signal.

The output of the holding means 28 is connected to the base of the transistor Q4 of the start / stop means 29 only via the input resistor R10, whereas the base of the transistor Q5 of the start notification means 30 is connected. Is further connected to the input resistor R directly connected to the base of the transistor Q4.
9 and the input resistor R12, so that when the output voltage of the holding means 28 is at a high level, most of the current flows to the base of the transistor Q4 and almost no current flows to the base of the transistor Q5. No flow,
The transistor Q5 does not turn on. That is, when the output voltage of the timer 26 is at the low level, the transistor Q5 of the activation notifying means 30 is turned off regardless of the output of the holding means 28, so that the voltage at the low level from the activation notifying means 30.
The (start notification signal) is not output to the work control device 7.

Next, the operation of the engine working machine will be described with reference to FIGS. 2 to 4. 2 is a timing chart when the engine 1 is started in a cold state, FIG. 3 is an enlarged view of a part of the waveform of the engine rotation speed in FIG. 2, and FIG. It is a timing chart at the time of starting.

In this embodiment, if the engine 1 is started at a rotation speed of 800 rpm or more and the working machine 2 has a normal load, the starter 3 is started after the engine 1 has been started. The engine 1 does not stop even if it is stopped. The first reference voltage value is the engine 1
Is adjusted to the output voltage value of the FV converter 21 when the rotation speed of the engine is 800 rpm, and the second reference voltage value is the FV when the rotation speed of the engine 1 is 1000 rpm.
The output voltage value of the converter 21 is adjusted.

First, the operation when the engine 1 is started in a cold state will be described with reference to FIG. Note that in FIG. 2, the rotation speed of the engine 1 is 1000 even after the start of the engine 1 is completed.
Maintains less than rpm. A key is inserted into the key switch 5 and the key switch 5 is manually turned as it is to operate the contact piece 16 from the off position to the starter position (at time t0). Then, power is supplied from the battery 6 to the start control device 4, the work control device 7, and the like. On the other hand, at this time t0, the engine 1 is stopped, so the FV converter 21
Becomes lower than the first reference voltage value and the second reference voltage value, and the outputs of the comparators 24 and 25 both become high level.

Therefore, a low level voltage is output from the timer 26, the relay L1 of the start / stop means 29 is turned on, and the relay contact S1 is closed. Then the battery 6
From the contact piece 16, the starter contact 52, and the relay contact S1, power is supplied to the starting device 3, and the starting device 3 operates. As a result, the engine 1 is started. Further, the output voltage of the holding means 28 becomes low level in response to the high level output of the comparator 25, and the activation notification means 30 outputs the high level voltage to the work control device 7. Therefore, the work control device 7 receives the high level voltage and controls the work machine 2 not to operate.

On the other hand, after the time t0, the rotation speed of the engine 1 increases with the operation of the starting device 3, reaches 800 rpm or more at the time t1, further increases, and then starts to decrease. At the time t2. It becomes 800 rpm or less again. The set time T1 of the timer 26 is preset so as to be longer than the time from the time point t1 to the time point t2.
Therefore, the output voltage of the F-V conversion unit 21 becomes equal to or higher than the first reference voltage value during the time from the time point t1 to the time point t2, and the output of the comparator 24 is at a low level (rotation increase notification signal).
However, the output voltage of the timer 26 remains at the low level because it returns to the first reference voltage value or less again after the time point t2.

The rotational speed of the engine 1 is t
After the time point t2, it starts to rise again and rises again. At time t3, it becomes 800 rpm or higher, and then continues to rise.
When the time at which the rotation speed of the engine 1 becomes 800 rpm or more becomes the time T1 set by the timer 26 or more (at time t4), the timer 26 outputs a high-level voltage as a rotation increase notification signal. The rotation speed of the engine 1 fluctuates little by little due to the intermittent combustion of the engine 1 as shown in FIG.
So-called chattering occurs, which is 0 rpm or less and then 800 rpm or more in a short period of time. This chattering period Tc is considerably shorter than the set time T1 of the timer 26. Therefore, the output voltage of the timer 26 maintains the low level during the chattering period Tc. As a result, as the rotational speed of the engine 1 changes little by little,
It is possible to prevent the start / stop of the starting device 3 from being repeated in small increments, and to prevent the rush current flowing into the drive motor 13 from repeatedly flowing in a short time, thereby causing deterioration or failure of the drive motor 13 in a relatively short period of time. it can.

The output of the high level voltage (rotational increase notification signal) from the timer 26 at the time t4 causes the relay L1 to be turned off and the relay contact S1 to be opened as a start / stop signal from the start / stop means 29. Be done. As a result, the power supply to the starting device 3 is cut off, the starting device 3 is stopped, and the driving of the engine 1 is stopped. It should be noted that at this time t4, the starting of the engine 1 has been completed, and even if the starting device 3 is stopped, the engine 1 does not stop. That is,
The start timing of the engine 1 can be reliably prevented by accurately determining the stop timing of the starter 3. Then, when the operator releases the key inserted into the key switch 5, the contact piece 16 automatically returns from the starter position to the on position by the action of the spring or the like.

Further, the high level output voltage from the timer 26 at the time point t4 causes the start notification means 30 to output a low level voltage as a start notification signal to the work control device 7, and the work control device 7 Receiving the start notification signal, the work machine 2 can be operated. On the other hand, by the output of the high level voltage (rotation increase notification signal) from the timer 26 at the time t4, the reference value switching means 27 causes the first reference voltage value to the comparator 24 to be 0 rpm when the rotation speed of the engine 1 is approximately 0 rpm. The output voltage value of the FV converter 21 in the (engine stopped state) is reduced to almost 0V.

Therefore, after the start of the engine 1 is completed, the load on the working machine 2 temporarily increases, and for example, even if the rotation speed of the engine 1 decreases to 800 rpm or less at time t5, the engine 1 does not stop. The output of the comparator 24 holds the low level. For this reason, the start notification means 3
From 0 to work control device 7, start notification signal (low level)
Is continuously output, and the work control device 7 continues the operation of the work machine 2 without interruption. As a result, the work machine 2 can be stably operated without being affected by load fluctuations.

When the working machine 2 is overloaded and the engine 1 is stopped at time t6, the output of the comparator 24 is inverted from the low level to the high level, and the output state of this high level changes to the timer. 26 set time T2
When the above is continued (at time t7), the output voltage of the timer 26 becomes low level, the reference value switching means 27 is reset, and the first reference voltage value of the low speed reference value setting means 22 is the rotational speed of the engine 1. Returns to the output voltage value of the FV converter 21 when is 800 rpm. On the other hand, with the inversion of the output voltage of the timer 26 from the high level to the low level at the time t7, the relay L1 of the start / stop means 29 is turned on.
Therefore, when the key switch 5 is manually turned to operate the contact piece 16 from the on position to the starter position again after the time point t7, the starting device 3 operates.

Next, the operation when the engine 1 is started after the engine 1 is stopped and before it is cooled will be described with reference to FIG. That is, the key switch 5 is manually turned to operate the contact piece 16 from the off position to the starter position.
At the 10th time point, the engine 1 has not yet rotated, and the outputs of the comparators 24 and 25 both become high level as described above.

Along with this, the timer 26 and the holding means 2
Both output voltages of 8 become low level, the relay L1 of the start / stop means 29 is turned on and the relay contact S1 is closed, the starter 3 is operated, and the high level voltage from the start notification means 30 is the work control device. Output to 7 and work machine 2
Is controlled to stop. On the other hand, the previous operation of the engine 1 sufficiently lubricates the engine 1, and as a result, the rotation speed of the engine 1 rapidly increases due to the operation of the starter 3.

Then, in a shorter time than the set time T1 of the timer 26, the rotation speed of the engine 1 is 800 rpm (first
Standard value), after this, at t11, 1000 rpm
When it becomes equal to or higher than the (second reference value), the output of the comparator 25 becomes low level (second rotation increase notification signal). Then, from the holding means 28 to the start / stop means 29, a high level voltage is applied.
The (second rotation increase notification signal) is output and the high-level output voltage is held. As a result, the transistor Q4 of the start / stop means 29 is turned on and the relay L1 is turned off, the power supply from the battery 6 to the starter 3 is stopped, and the starter 3 is stopped. At this time, the start of the engine 1 is completed.

On the other hand, as described above, the high level output voltage of the holding means 28 is not transmitted to the start notification means 30, and the high level output voltage from the start notification means 30 to the work control device 7 is maintained, The work machine 2 remains stopped. On the other hand, at the time t12 when the set time T1 of the timer 26 elapses after the rotation speed of the engine 1 becomes 800 rpm or more after the start of the engine 1 is completed, the high-level voltage (rotation increase notification signal) is output from the timer 26. The start notification means 30 outputs the start notification signal (low level) to the work control device 7, and the work machine 2 can be operated.

On the other hand, the rotation speed of the engine 1 is 800 rpm because an excessive load is applied to the working machine 2, for example.
When the engine 1 is stopped at time t13 before the set time T1 of the timer 26 has elapsed from the above, even if the output of the comparator 25 becomes high level when the engine 1 is stopped, the holding unit 28 stops. , Holds high level output voltage. Therefore, the relay L1 of the starting / stopping means 29 is maintained in the off state as it is, and the starting device 3 does not operate even if the key switch 5 which has returned to the on position is turned to the starter position again. Further, since the output voltage of the timer 26 remains low level at the time point t13,
The high level output voltage from the activation notifying unit 30 to the work control device 7 is also maintained, and the work machine 2 remains stopped.

Then, when the key switch 5 is returned to the off position, the supply voltage + B of the battery 6 to the holding means 28 is stopped, the holding means 28 is reset, and the output voltage of the holding means 28 returns to the low level. After that, when the key switch 5 is manually turned at t14 to operate the contact piece 16 from the off position to the starter position, the relay L1 of the start / stop means 29 is turned on and the starter 3 is operated.

That is, the engine 1 is not properly mounted on the engine 1 or the work 1 is loaded with an excessive load.
Is not started, the engine 1 is not started even if the engine 1 is repeatedly driven by the starting device 3, and the high-speed rotation of the drive motor 13 of the starting device 3 due to the increase in the high-speed rotation immediately after the engine 1 is driven. Drive motor 13 repeatedly
May deteriorate or malfunction. Further, the capacity of the battery 6 is wasted. In these cases, the starting device 3 is quickly stopped, and the working device 2 is returned to a normal state after the power supply to the working device 2 and the work control device 7 is stopped, and then the starting device 3 is operated. That protects the starting device 3 and the battery 6. Therefore, when the rotation speed of the engine 1 becomes 1000 rpm or more, the starting device 3 is immediately stopped, and the starting device 3 cannot be reactivated unless the key switch 5 is returned to the off position.

As a result, deterioration and failure of the drive motor 13 due to repeated high-speed rotation of the drive motor 13 can be reliably prevented, and the starter 3 can be held in a stopped state so that the worker can install the work machine 2 properly or can work properly. It is possible to promote the release of the excessive load on the machine 2.

The above embodiment can be modified as follows. That is, in the above embodiment, the rotation speed of the engine 1 is detected by detecting the gear teeth of the ring gear 10 by the rotation speed detecting means 11, but the generated voltage of the alternator (or dynamo) 8 is low at the rotation speed of the engine 1. Since it is sometimes proportional to the rotation speed, the rotation speed of the engine 1 may be detected by measuring the power generation voltage of the alternator (dynamo) 8. Further, the rotation speed of the engine 1 may be detected using a tachometer (engine tachometer) or the like.

It is also possible to configure the start control device 4 with a microcomputer, a memory, etc., and program it to perform the same operation as the start control device 4 of the above embodiment. Further, the starting control device 4 can be configured by a general-purpose IC, such as the holding means 28 of the starting control device 4 is configured by a general-purpose latch IC.

In the above embodiment, the starting and stopping means 29 is used.
Although the opening operation of the relay contact S1 of the relay L1 is used as the start / stop signal, the low-level voltage may be output from the start / stop means 29 to the starter 3 as the start / stop signal. In this case, the starting device 3 is configured so that its control device operates at the high level output voltage from the starting and stopping means 29 and stops at the low level output voltage.

[Brief description of drawings]

FIG. 1 is a diagram illustrating a configuration of an engine working machine to which an embodiment of a starting control device of the present invention is applied, FIG. 1 (A) is an overall schematic configuration diagram of the engine working machine, and FIG. 1 (B) is It is a circuit diagram of the said start control apparatus.

FIG. 2 is a timing chart when the engine is started in a cold state.

FIG. 3 is an enlarged view of a part of a waveform of engine rotation speed in FIG.

FIG. 4 is a timing chart when the engine 1 is restarted before it cools.

[Explanation of symbols]

1 ... Engine, 2 ... Working machine, 3 ... Starting device, 4 ... Starting control device (control means), 11 ... Rotation speed detecting means, 22 ... Low speed reference value setting means (first reference value setting means), 23 ... High speed Reference value setting means (second reference value setting means), 24 ... Comparator (first comparator), 25 ... Comparator (second comparator), 26 ... Timer, 27 ... Reference value switching means, 2
8 ... Holding means, 29 ... Starting / stopping means, 30 ... Startup informing means.

Claims (2)

[Claims] 1. A work machine (2) is drivably connected to an engine (1) and a starting device (3) for starting an engine is connectable to detect the rotational speed of the engine (1). Control means (4) having rotational speed detection means (11) and comparator (24)
Is provided, and the outputs of the rotation speed detecting means (11) and the reference value setting means (22) are connected to the comparison input of the comparator (24) respectively, and the output of the comparator (24) is started and stopped ( 29) and the start notification means (30) respectively, and the rotation speed of the engine (1) is set to the reference value setting means (2).
When it becomes equal to or larger than the reference value preset in 2), the rotation increase notification signal is sent from the comparator (24) to the start / stop means.
(29) and the start notification means (30), and a start stop signal is output from the start stop means (29) in response to the rotation increase notification signal from the comparator (24). At the same time, the start notification means (30) outputs the start notification signal. When the start stop signal is output from the start stop means (29), the starter (3) is stopped. To control
In a start control device for an engine work machine configured to control the work machine (2) to an operable state when a start notification signal is output from the start notification means (30), the comparator (24) Output and the starting and stopping means
A timer (26) is interposed between (29) and the input of the start notification means (30), and the output of the timer (26) is connected to the reference value switching means (27). The output of (27) is used as the reference value setting means.
Connected to (22), when the rotation increase notification signal from the comparator (24) continues for a predetermined time (T1) or more, the timer (26)
The reference value switching means (27) is configured to output the rotation increase notification signal from the reference value setting means (2) according to the rotation increase notification signal from the timer (26).
A starting control device for an engine working machine, which is configured to reduce the reference value of 2). 2. The engine work machine starting control device according to claim 1, wherein the control means (4) includes a second reference value setting means (23) and a second reference value setting means (23).
It has a comparator (25) and a holding means (28), and this second reference value setting means (23) sets a second reference value larger than the first reference value of the first reference value setting means (22). The outputs of the rotation speed detecting means (11) and the second reference value setting means (23) are respectively set in advance and connected to the comparison input of the second comparator (25), and the second comparator is connected.
The output of (25) is connected to the input of the starting and stopping means (29) through the holding means (28), and when the rotation speed of the engine (1) is equal to or higher than the second reference value, the second The comparator (25) is configured to output the second rotation increase notification signal to the holding means (28), and the holding means (28) outputs the second rotation increase notification signal from the second comparator (25). A starting control device for an engine working machine, wherein the starting control device (29) outputs the second rotation increase notification signal and holds the output.