JPS60162576A - Engine starter for engine welder - Google Patents

Abstract

PURPOSE:To start automatically and surely an engine by providing a photocoupler which operates when both electrodes connected to a generator are short-circuited and an engine starting circuit connected to the photocoupler. CONSTITUTION:When both electrodes W1 and W2 are short-circuited by bringing instantaneously a welding rod to contact with the materials to be welded, a photocoupler C1 operates, turns on a relay X12 to close its contact X121, turns on relays X13, X14 to close the contact 142 of the relay 14 and turns on a relay XE to close its contact XE1. A DC voltage is then impressed over the entire part of an engine control device via switches S1, S2. The relay X14 latches itself by closing the contact X141, then the contact X131 of a relay 13 closes to trigger a buzzer BZ and to operate a heater H of the engine, thereby preheating the engine. The contact T1 is closed by the operation of a timer T4 upon timing out of said timer and since the contact X132 of the relay X13 is held closed, a relay X7 turns on to close the contact 71, thereby actuating the starter S of the engine. The engine is thus started.

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 a manual switch provided on the engine body, so a worker carrying a welding rod holder during welding work could start the engine at any time at the work site. It often took a long time to start work.

The present invention starts the engine remotely on the welding rod side, and moreover, by simply bringing the welding rod held in the welding rod holder into contact with the workpiece (base metal), the engine can be started automatically and without malfunction (reliably). It was designed so that it could be done.

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 engine is characterized in that the starting circuit is actuated and self-maintained, and the engine is automatically started by the starting circuit.

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 roughly 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, which control the DC voltage of battery B (
For example, it is driven by 12V).

The engine (not shown) is controlled by this engine control device.
When welding work is performed using the welding alternator G1, which is driven by the engine, and when welding is performed using the alternator G2 for power tools, which is also driven by the engine. The control mode differs depending on whether the tool is operated or not. Firstly, in the case of welding, engine startup, idling, high-speed operation, low-speed operation,
Stopping will be explained in order.

"Welding Waiting Control" (Startup) Turn on the engine key switch Sl, and set the manual-automatic mode selection switch S2 to the automatic side (lower side in the drawing) than the neutral position. In this state, the welding rod held in the welding rod holder (not shown, which is connected to one or more negative electrodes of the DC electrode that rectified the alternating current of the AC power generator taGl) is attached to the workpiece. They are brought into instantaneous contact to instantaneously short-circuit between both electrodes w, , w2. Relay X is connected to negative electrode W2
8 b contact X8. and the first photocoupler C1 via a resistor.
A light emitting element is connected to the light receiving element, and a relay X1 is connected to the light receiving element.
2 are connected. This light receiving element is connected to the automatic side of switch S2.

Therefore, when the electrodes Wt and w2 are short-circuited, the photocoupler C1 operates, the relay X12 is turned on, and its a contact X121 is closed. This allows relays X13 and
14 is turned on, and the a contact X142 of this relay
is closed, relay XE is turned on, its a contact (DC power switch) XE+ is closed, and the DC voltage of battery B is applied to the entire engine control device via the switches SL and S2. Relay X14 maintains itself by closing its a contact X141. And relay X1
By closing the a contact X131 of No. 3, the buzzer BZ
is activated, the engine heater H is activated to preheat the engine, and the timer T4 is activated to close its a contact T41 after a set time.
Since the a contact X132 of No. 13 is closed, the relay X7 is turned on, and the a contact X7.13 is closed. is closed, the engine starter S is activated, and the engine starts.

In other words, when the welding rod is momentarily brought into contact with the workpiece,
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 workpiece, the current flowing between the electrodes w, w2 has large fluctuations, but the relay The welding rod is electrically insulated, so it turns on accurately, and the engine can be started remotely, automatically, and reliably at the work site simply by momentarily contacting the welding rod with the workpiece.

(Idle running) When Enshinker 1 is started in this way (low-speed operation at startup), both AC generators Gl.

G2 and dynamotor D are driven, and the voltage of this dynamotor D turns on IJ relay x8, its a contact X84 closes and relay XD turns on, and its b contact
D is opened and heater H and buzzer BZ are turned off. 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 to short-circuit between the electrodes w, , w2. This short circuit causes current to flow through the primary terminal P of the alternator Gl, which is detected by the current sensor CT. The current sensor CT is configured by passing a detected conductor (for example, an electric wire) through a magnetic field sensor constituting a ring-shaped closed magnetic path, and detecting the magnetic field generated by current flowing through the detected conductor with 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, turning on relay Bx1 and closing its a contact RX11. . At this time, since the a contact X83 of the relay X8 is already closed, the relay Xi is turned on and its contact X11 is closed. At this time, the a contact T5 of the timer 1-5. is already closed, relay X3 is turned on and its a contact X3. closes, relay X3 self-holds, high-speed solenoid L1 is energized, the engine speed change mechanism is switched, and the engine shifts to high-speed operation.

This solenoid L1 is a high-speed operation state button switch S3
It can also be energized by pressing , so the engine can also be manually shifted to high-speed operation.

When the engine is in high-speed operation, both electrodes w,,
A predetermined voltage is generated between w2 and arc welding becomes possible.

Also, the relay RB connected between these electrodes is turned on (the a contact X82 of the relay X8 is already closed).
, its b contact RB.

opens, and the a contact RB2 closes. 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. When both electrodes w, , w2 are short-circuited and the voltage becomes approximately O, the third photocoupler c3 connected thereto is turned off, relay RX2 is turned off, and its b contacts RX2. closes. At this time, since the a contact RX12 of the relay RXI and the a contact T52 of the timer T5 are closed, the timer T1 is turned on. When the welding rod is brought into continuous contact with the workpiece for the time set by timer T1 (approximately 2 seconds) or longer, timer TI closes its a contact TI2 and holds itself, and its b contact T
ll opens, which activates the buzzer BZ and turns off the relay X3, opening its a contact X3. opens, the high-speed operation solenoid L1 is deenergized, and the engine returns to low-speed operation.

When the limited deceleration switch S4 is turned on, the engine automatically shifts to low-speed rotation even if arc welding is interrupted for a predetermined period of time or more.

That is, when arc welding is continued and interrupted, the relay RB is turned on and its a contact RB2 is closed, and the timer T12 is activated and after the set time has elapsed, the a contact T I2+ is activated.
is closed, the b contact T122 is opened, the relay x3 is turned off, and the high-speed operation solenoid L1 is deenergized.

(Stop) After the welding rod is brought into continuous contact with the object to be welded as described above and the engine is returned to low-speed operation, the welding rod is brought into contact with the object to be welded.

During this time, the buzzer BZ continues to sound, and when the set time of the timer T2 (approximately 4 seconds) has elapsed, the a contact T21 closes and the relay R1 turns on, and the contact R11 closes and the relay R1 self-holds. The stop solenoid L2 is energized and the engine is stopped. Moreover, the buzzer BZ also stops sounding by opening the b contact T22 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, then Contact T13. closes, relay R1 also turns on, and the engine stops.

When relay R,1 holds itself, its b contact R12 opens and relay X7 is cut off from battery B, so
Even if the welding rod comes into contact with the workpiece, the starter S does not operate. Therefore, the engine is prevented from restarting during the above-mentioned stop operation.

When the a contact R1 of the relay R1 closes, the timer T3 also operates, and after the set time (about 5 seconds), the b contact T3. opens and relay R1 turns off, and at the same time, b contact T32 opens and relay X14 also turns off, and the closed a contact
142 opens, relay XE turns off, and contact A, which is the DC power switch, opens and returns to its original state. The simple operation of bringing the welder into contact with the object to be welded can be done consistently and fully automatically, and can also be controlled remotely and as desired by the welding operator at the work site.

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

(Safe operation) If the engine in question 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 the car's clutch is not in neutral. There is.

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, this switch S2. Micro switch S
6, current from battery B flows through the light emitting element of the first photocoupler CI, relay X12 is turned on and its a contact X121 is closed, buzzer BZ is activated, and relay XF is turned on and its a contact XF closes, relay XF self-holds, and its b contact XF2 opens, so
Since relay XE is disconnected from battery B and therefore its a contact XE does not close, the engine will not start even if the welding rod is brought into contact with the object to be welded.

To release this state, put the clutch in neutral, then open the release pushbutton switch s7 to release the relay
Release F's self-hold.

Further, when switch S2 is set to the manual side, relay XE is turned on and its a contact XE is closed, but when microswitch S6 is on, b contact T6 of timer T6 is turned on. Current from the battery B flows through the first photocoupler CI via the microswitch S6 and the relay X12. Since XF is turned on and a contact XF2 of relay XF is opened, relay XE is immediately turned off. Therefore, the engine will not start in this case as well.

When the microswitch S6 is off (clutch is in neutral), no matter whether the switch S2 is set to the automatic or manual side, the timer T6 is set (approximately 2 seconds).
and its b contact T6. , T62 is open, so relay XF does not turn on.

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

"Control when using power tools" (Startup) When engine key switch S1 is turned on and manual-automatic mode selection switch S2 is set to the automatic side, the current of battery B is transferred to b contact XA of relay XA, to one electrode of the single-phase 100V AC power source E, and to the three-phase 200V AC power supply via the B contact XA2 of the relay XA.
■ Reaches the ■ terminal of the AC power supply. In this state, turn on the power switch of the power tool connected to outlet E or
When the power switch of the power tool connected to the phase 200V AC power terminal [1, V, W is turned on, the current from battery B enters the light emitting element of the first photocoupler C1 through the b contact XA4 of relay XA. , relay X12 is turned on, the engine is automatically started as in the case of welding described above, and relay X8 is turned on by the voltage of dynamotor D.

(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) Even after the set time of timer T5 has elapsed, the operation continues for 100 or 20 seconds.
When the power switch of the power tool for 0■ is turned on, the first photocoupler C1 continues to operate, so current flows to relay X1 via the closed A contact X8a of relay X8, and this relay XI is turned on, its a contact X1+ is closed, relay X3 is turned on, and the engine shifts to high-speed operation as in the case of welding. Due to high-speed operation of the engine, a predetermined voltage is generated in the AC generator IaG2,
This voltage turns on relay XA (A contact X32 of relay X3 is already closed), and its B contact) (a
1 to XA4 are open, the 100V and 200V AC paths and the 12V DC path are isolated. Also, timer T
After the set time (approximately 2 seconds) after A is activated, its a contact TAI
closes, relay XB turns on, and its A contact XB closes, and a single-phase AC voltage of 100μ is applied to terminals 0-W of the AC power supply, and a three-phase AC voltage of 200μ is applied to terminals U-V-W. , the 100V or 200V power tool connected to it is driven.

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

In addition, relay XA becomes relay XD when the engine is idling.
Since the b contact XD2 of is open, it will not turn on.

(Low speed operation) Turn off the power switch of the 100V and 200V power tools (in this case, welding work is also interrupted)
, since no current flows through the path leading to terminals O and W, second photocoupler C2 becomes inactive and relay RX
I turns off and its b contact RX 12 closes. When using power tools, the limited deceleration switch S is usually
4 is kept on, and when b contact XI2 closes (
At this time, the a contact RB2 of the relay XB is closed because the welding work is interrupted), the timer T12 is activated, and the b contact T122 of the relay XB is opened after the set time, and the relay X3
self-holding is released, the high-speed solenoid L1 is deenergized, and the engine automatically shifts to low-speed operation.

If 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 will continue to operate at high speed 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 of all power tools are turned off (including when welding work is interrupted) continues for more than the set time of timer T13, the a contact T13 of this timer T13
1 force Z closes, relay R1 self-holds as described above, stop solenoid L2 is energized, and the engine stops -0 dynamically.

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 description, according to the present invention,
The engine can be started automatically by the simple operation of bringing the welding rod into contact with the object to be welded, and can also be started remotely at the work site by welders and others as they wish.

In addition, a photocoupler is interposed between the electrodes of the generator and the starting circuit, and the starting circuit is operated indirectly via the photocoupler, so when the welding rod comes into contact with the workpiece, the current flowing between the two electrodes changes. Even if the amount is large, the engine can be started accurately.

[Brief explanation of drawings]

The drawing is an electrical circuit diagram showing an embodiment of the present invention. Gl...alternator, w,, w2...electrode, C1...
...Photocoupler, 3...Start circuit.

Claims (1)

[Claims] 1. An engine, a generator driven by the engine, and a welding rod holder connected to one electrode of the generator, the welding rod holder holding the welding rod, and the other electrode of the generator In the engine welder, which is connected to the workpiece and an arc current is passed between the welding rod and the workpiece to melt the welding rod, a photocoupler is connected to the generator and operates when a short circuit occurs between the two electrodes. An engine starting device for an engine welder, characterized in that it is connected to the photocoupler, operates and self-maintains when the photocoupler is operated, and starts the engine.