JPH0359784B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an engine starting device for starting an engine in an engine welder in which a generator is driven by an engine and arc welding is performed using a welding rod.

Conventional engine welders were started by manually turning on the manual switch provided on the engine body, so workers carrying out welding work while holding a welding rod holder had to start the engine at any time at the work site. I often couldn't start it up and it took a long time to start working. It is also known that when performing welding work at high places, an engine generator installed on the ground can be started by grounding the welding rod at high places, as described in Japanese Patent Application Laid-Open No. 57-24448. However, stable startup of the engine generator could not be expected.

The present invention enables the engine to be started remotely on the welding rod side, automatically and reliably without malfunction by simply bringing the welding rod held in the welding rod holder into contact with the workpiece (base metal). It has been made possible to do so.

That is, in the present invention, a photocoupler is connected to a generator, a starting circuit is connected to this photocoupler, and when a welding rod is brought into contact with a workpiece to short-circuit both electrodes of the generator, the photocoupler operates. The starting circuit is activated and self-maintained, and the engine is automatically started by the starting circuit, and the generator is started by the operation of the power switch of the power tool.

An embodiment of the present invention will be described below.

The drawing is an overall electrical circuit diagram of an engine control device including an engine starting device according to the present invention. This engine control device is broadly divided into a DC power supply circuit 1, an AC power supply circuit 2, a starting circuit 3 which occupies the main part of the present invention, an idling circuit 4, a high-speed operation circuit 5, and a low-speed operation circuit 6. , a safety circuit 7, and a stop circuit 8.
12V).

The engine (not shown) is fully automatically controlled by this engine control device, and there is also a welding alternator G1 driven by the engine.
The control methods are somewhat different depending on whether welding is carried out by the engine or when the power tool is operated by the alternator G2 for the power tool, which is also driven by the engine. When starting the engine, idling, high-speed operation, low-speed operation,
Stopping will be explained in order.

"Control during welding" (Startup) Turn on the engine key switch S1, and move the manual-automatic mode selection switch S2 from the neutral position to the automatic side (shown with a solid line), and when it is manual, move it to the manual side (shown with a dotted line) Set it to . In this state, the welding rod held in the welding rod holder (not shown, which is connected to the negative _W2 side of the DC electrode that rectified the alternating current of the alternator G1) is covered. The electrodes W 1 and W 2 are brought into instantaneous contact with the workpiece to instantaneously short-circuit between the electrodes W ₁ and W ₂ . Negative electrode _W2 has b contact X of relay X8
The light emitting element of the first photocoupler C1 is connected via 8 ₁ and a resistor, and the relay X1 is connected to the light receiving element.
2 are connected. This light receiving element is switch S
2 is connected to the automatic side.

Therefore, when the electrodes W ₁ and W ₂ are short-circuited, the photocoupler C1 operates, the relay X12 is turned on, and its a contact X12 ₁ is closed. This turns on relays X13 and X14, closes the a contact X14 ₂ of relay X14, turns on relay XE, and closes the a contact (DC power switch) XE ₁
is closed, and the DC voltage of battery B is applied to the entire engine control system via the switches S1 and S2. Relay X14 maintains itself by closing its a contact X14 ₁ . Then, by closing the a contact X13 ₁ of relay X13,
Buzzer BZ is activated, engine heater H is activated to preheat the engine, timer T4 is activated, and after a set time, the a contact T4 is activated.
₁ closes, at this time the a contact X13 of relay X13 ₂
Since it is closed, relay X7 is turned on, its a contact _X71 is closed, engine starter S is activated, and the engine is started.

That is, when the welding rod is momentarily brought into contact with the object to be welded, a warning is issued by the buzzer BZ, the engine is preheated, and the engine is automatically started after the time set by the timer T4.

In this case, when the welding rod is brought into contact with the object to be welded, a flow occurs between the electrodes W ₁ and W ₂ . Relay X1
2 is electrically insulated from these electrodes W ₁ and W ₂ by the photocoupler C1, so that they can be turned on accurately, and simply by momentarily contacting the welding rod with the object to be welded, the engine can be turned on. can be activated remotely, automatically, and reliably at the work site.

(idling) When the engine starts in this way (operates at low speed at startup), both alternators G
1, G2 and dynamotor D are driven, relay X8 is turned on by the voltage of this dynamotor D, its a contact _X84 is closed and relay XD is on, and its b contact _XD1 is opened and heater H is turned on. and buzzer
BZ is cut. At the same time, timer T5 is activated, and the engine is suspended from shifting to high-speed operation and idled for only the set time.

(High-speed operation) While the engine is idling (low-speed operation), the welding rod is momentarily brought into contact with the workpiece again, and both electrodes are
Short-circuit between W ₁ and W ₂ . Due to this short circuit, current flows through the primary side terminal P of the alternator G1, which is detected by the current sensor CT. current sensor
In CT, a conductor to be detected (for example, an electric wire) is passed through a magnetic field sensor that forms a ring-shaped closed magnetic path, and the magnetic field generated by current flowing through the conductor is detected by the magnetic field sensor. It is used to detect current.

When a current is detected by the current sensor CT and a slight voltage is generated, it is amplified and applied to the second photocoupler C2, so this photocoupler operates and relay RX1 is turned on, and its a contact RX1 ₁
closes. At this time, the a contact X8 of the above relay X8
₃ is already closed, relay X1 turns on and its contact X1 ₁ closes. At this time, since the a contact T5 ₁ of the timer T5 is already closed, the relay _X3 is turned on, the a contact
1 is energized, the transmission mechanism of the engine is switched, and the engine shifts to high-speed operation.

This solenoid L1 can also be energized by pressing the high-speed operation pushbutton S3, so the engine can also be manually shifted to high-speed operation.

When the engine is in a high-speed operating state, a predetermined voltage is generated between the electrodes W ₁ and W ₂ , making arc welding possible. Further, the relay RB connected between these electrodes is turned on (the a contact X8 ₂ of the relay X8 is already closed), its b contact RB ₁ is opened, and the a contact RB ₂ is closed. This relay RB
is turned off when arc welding is performed and turned on again when interrupted.

(Low speed operation) The welding rod is brought into continuous contact (welding) with the workpiece while the engine is running at high speed. both electrodes
When W ₁ and W ₂ are short-circuited and the voltage becomes almost 0, the third photocoupler C3 connected to it is turned off, relay RX2 is turned off, and its b
Contact RX2 ₁ closes. At this time, the above relay RX1
a contact RX1 ₂ and a contact T5 of the above timer T5
₂ is closed, so timer T1 is turned on.
If the welding rod is kept in contact with the workpiece for more than the time set by timer T1 (approximately 2 seconds), timer T1
1 closes its a contact T1 ₂ to hold itself and opens its b contact T1 ₁ , which causes the buzzer BZ
is activated, the relay X3 is turned off, its a contact _X31 is opened, the high-speed operation solenoid L1 is deenergized, and the engine returns to the low-speed operation state.

If you turn on the limited deceleration switch S4,
Even if arc welding is interrupted for a predetermined period of time or longer, the engine automatically shifts to low speed rotation.

In other words, if arc welding is interrupted continuously,
The relay RB turns on and its a contact RB ₂ closes, and the timer T12 operates and after a set time, its a contact T12 ₁ closes and its b contact T12 ₂
opens, relay X3 is turned off, and high-speed operation solenoid L1 is deenergized.

(Stop) Even after the welding rod is brought into continuous contact with the workpiece as described above and the engine is returned to low-speed operation,
Furthermore, the welding rod is brought into contact with the object to be welded.
During this time, the buzzer BZ continues to sound, and eventually the timer T
When the set time (approximately 4 seconds) has elapsed, the a contact T2 ₁ closes and the relay R1 turns on, the contact R1 ₁ closes and the relay R1 self-holds, and the stop solenoid L2 is energized. The engine will stop. Further, the buzzer BZ also stops sounding by opening the b contact ₂₂ of the timer T2.

On the other hand, if the limited deceleration switch S4 is turned on, even after interrupting arc welding and shifting to low-speed operation as described above, if arc welding is not continued and the set time of timer T13 has elapsed, the a Contact _T131 closes, relay R1 also turns on, and the engine stops.

When relay R1 self-holds, its b contact R1
₂ opens and the aforementioned relay X7 is cut off from the battery B, so the starter S will not operate even if the welding rod comes into contact with the object to be welded. Therefore, the engine is prevented from restarting during the above-described stop operation.

When the a contact R1 ₁ of relay R1 closes, timer T
3 also operates, and after the set time (approximately 5 seconds) its b contact _T31 opens and relay R1 turns off.
b contact T3 ₂ opens and relay X14 also turns off,
The closed A contact X14 ₂ opens and relay XE
is turned off, and the a contact, which is the DC power switch, is turned off.
The XE ₁ opens and returns to its original state, and all operations, including engine preheating, startup, high-speed operation, low-speed operation, and stopping, are performed consistently and fully automatically by simply touching the welding rod to the workpiece. What's more, the welding operator himself/herself can control it remotely and as desired at the work site.

Note that the engine can also be stopped manually by turning on the manual stop pushbutton S5.

(Safe operation) If the engine is a car engine, the engine control device will not start the engine unless the car's clutch is in neutral, and will be prevented from starting if it is not in neutral. It's summery.

That is, when the clutch is set to a position other than neutral, the microswitch S6 is turned on, and when the manual-automatic mode selection switch S2 is set to the automatic side (shown with a solid line), this switch S2 is turned on. , a current from the battery B flows through the light emitting element of the first photocoupler C1 via the micro switch S6, turning on the relay X12, closing its a contact _X121 , activating the buzzer BZ, and turning on the relay XF. , its a contact XF ₁ closes and relay XF holds itself, and its b
Since the contact XF ₂ is open, the relay XE is cut off from the battery B, and the a contact XE ₁ is not closed, so the engine will not start even if the welding rod is brought into contact with the workpiece. To release this state, after setting the clutch to neutral, open the release push button switch S7 to release the self-holding of the relay XF.

Also, set switch S2 to the manual side (indicated by a dotted line).
When set to , relay XE is turned on and its a contact XE ₁ is closed, but when micro switch S6 is on, a signal is sent to first photocoupler C1 via b contact T6 ₁ of timer T6 and micro switch S6. Current flows from battery B, and relays X12 and XF turn on in the same way as when set to automatic, and relay XF's a contact _XF2 opens, so relay XE immediately turns off. Therefore, the engine will not start in this case as well.

When the micro switch S6 is off (when the clutch is in neutral), regardless of whether the switch S2 is set to the automatic side or the manual side, its b contacts T6 ₁ and T6 are closed after the time set by the timer T6 (approximately 2 seconds). ₂
is open, so relay XF does not turn on.

Next, control when using a power tool will be explained.

"Control when using electric tools" (Start) When engine key switch S1 is turned on and manual-automatic mode selection switch S2 is set to automatic, the current of battery B is
It reaches one electrode of the outlet E of the single-phase 100V AC power supply through the b contact XA ₁ of XA, and reaches the V terminal of the three-phase 200V AC power supply through the b contact XA ₂ of the relay XA. In this state, turn on the power switch of the power tool connected to outlet E or the 3-phase 200V
When the power switch of the power tool connected to the AC power terminals U, V, and W of the relay is turned on, the current from the battery B passes through the b contact XA ₄ of the relay X1
2 is turned on, the engine is automatically started as in the case of welding described above, and the voltage of the dynamotor D turns on the relay X8.

(Idle running) As in the case of welding, the engine is inhibited from shifting to high-speed operation for a set time after startup by the action of timer T5.

(High-speed operation) If the power switch of the 100V or 200V power tool remains on even after the time set by timer T5 has elapsed, the first photocoupler C1 continues to operate, so the closed a contact of relay X8
Current flows through relay X1 through relay X1, turning on relay X1, closing its a contact _X11 and turning on relay X3, and _the engine shifts to high-speed operation as in the case of welding. Due to the high speed operation of the engine, a predetermined voltage is generated in the alternator G2, and this voltage turns on the relay XA (the a contact _X32 of the relay X3 is already closed).
Since the contacts Xa ₁ to X _-4 are open, the 100V and 200V AC paths and the 12V DC path are isolated. Also,
Timer TA operates and after the set time (approximately 2 seconds), its a contact TA ₁ closes, relay XB turns on, its a contact XB ₁ closes, and the terminals O-W of the AC power supply are connected.
A 200V three-phase AC voltage is applied to the 100V single-phase AC voltage and U-V-W, and a 100V or 200V power tool connected thereto is driven.

In this state, a current flows through the path leading to terminal O or W, which is detected by the current sensor CT, and the second photocoupler C2 is activated, causing the relay to
RX1 is turned on.

Note that relay XA is never turned on because the b contact XD ₂ of relay XD opens when the engine is idling.

(Low speed operation) When the power switches of the 100V and 200V power tools are turned off (in this case, welding work is also interrupted), current will no longer flow through the paths leading to terminals O and W, so the second photocoupler C2 becomes inoperable, relay RX1 turns off, and its b contact
RX1 ₂ closes. When using power tools,
Normally, the limited deceleration switch S4 is kept on, and when the B contact X1 ₂ closes (at this time, the A contact RB ₂ of the relay XB is closed because the welding work is interrupted), the timer T12 is activated, and after the set time, its b contact _T122 opens, the self-holding of relay X3 is released, and the high-speed solenoid L
1 is deenergized and the engine automatically shifts to low speed operation.

When the power switch of one of the power tools is turned on or welding work is started within the time set by timer T12, the engine remains in high-speed operation because relay X3 has not been released from self-holding. maintain.

If the limited deceleration switch S4 is turned off, the timer T12 does not operate, so the engine does not automatically shift to low-speed operation.

(Stop) If the state in which the power switches for all power tools are turned off (including when welding work is interrupted) continues for the time set by timer T13, the a contact _T131 of this timer T13 closes, and as described above, Relay R1 self-holds and stops solenoid L2
is energized and the engine automatically stops.

Note that electrical equipment other than power tools may be connected to the 100V outlet E and the terminals U, V, and W of the 200V three-phase AC power supply, and in that case, the engine will be controlled in the same way as above. be done.

As is clear from the above, according to the present invention, the engine can be started automatically by the simple operation of bringing the welding rod into contact with the workpiece, and even remotely by the welding operator himself at the work site. , you can do whatever you want.

In addition, a photocoupler is interposed between the electrode of the generator, the power switch circuit of the power tool, and the starting circuit, and the starting circuit is operated indirectly via the photocoupler. The engine can be started accurately by closing the tool switch.

[Brief explanation of drawings]

The drawing is an electrical circuit diagram showing an embodiment of the present invention. G1...Alternator, _W1 , _W2 ...Electrode, C1
...Photocoupler, 3...Start circuit.

Claims (1)

[Claims] 1 An engine, a generator driven by the engine, and a welding rod connected to one electrode of the generator, while the other electrode of the generator is connected to the workpiece, and the welding rod is connected to the workpiece. An engine starting device for an engine welder that melts a welding rod by flowing an arc current between the welding rod and the welding object includes a photocoupler circuit that is connected to the generator and operates when a short circuit occurs between the two electrodes, and the photocoupler. The circuit is connected to the power switch circuit of the power tool, and by shorting with a welding rod or closing the switch of the power tool, it is connected to this photocoupler, and when it is operated, it operates and holds itself, and starts the engine. An engine starting device for an engine welder, characterized in that a starting circuit and a starting circuit are each configured independently.