JPS60164663A - Safety apparatus for engine dynamo - Google Patents

Abstract

PURPOSE:To prevent the inadvertent start of an engine in a simple ways by installing a safety relay which deenergizes a power-source relay when a photocoupler is operated during the time when a timer is operated by the turning-ON of a manual switch. CONSTITUTION:When a clutch is set at a position other than neutral, a microswitch S6 is in ON-state. Therefore, when a manual-automatic mode selecting manual switch S2 is automatically turned ON, an electric current flows into the luminous element of a photocoupler C1 through the manual switch S2 and the microswitch S6, and a relay X12 is turned ON, and a a-contact 121 is closed to operate a buzzer BZ, and a safety relay XF is turned ON. Since the a-contact XF1 of the relay XF is closed and self-retained, and a b-contact XF2 is opened, the relay XE is cut-off from a battery B. Since the a-contact XE1 is not closed, an engine is not started even if a welding rod is brought into contact with a welded article, and safety is secured.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a safety device for preventing inadvertent starting of an engine in an engine generator for operating an arc welding tool, a power tool, etc.

The present applicant has developed a Japanese Patent Application Laid-Open No. 57-1995 as this type of engine generator.
As disclosed in Japanese Patent No. 112977, a welding rod held in a welding rod holder, which is an arc welding tool, is attached to a workpiece (
We already offer products that can automatically start the engine each time the product momentarily contacts the base material (base material) and makes contact with the ground.

1 My skin feels like “I’m going to do it.”

However, according to this, when the manual switch is turned on to turn on the power to the engine control circuit that controls engine starting, stopping, etc., if the welding rod is already in contact with the workpiece, the engine will start immediately. In other words, it started up carelessly and was dangerous.

Furthermore, if the engine is a car engine, there is a risk that the engine will start even though the car's clutch is not in neutral, causing the car to run out of control.

An object of the present invention is to provide a safety device that can easily prevent such inadvertent engine starting.

The safety device of the present invention for starting the engine includes a starting circuit that starts the engine;
A power supply relay that is energized when the manual switch is turned on and establishes continuity between the starting circuit and the power supply, and when continuity is established between the DC output terminal or AC output terminal of the power generator or when a specific switch is turned on. A photocoupler that operates when the above manual switch is turned on to activate the starting circuit, and a timer that operates for a set time when the manual switch is turned on.
It consists of a safety relay that is energized to de-energize the power supply relay when the photocoupler operates while the timer is operating.

One Piece - JL - Therefore, after turning on the manual switch and elapses the time set on the timer, for example, bring the welding rod into contact with the object to be welded to establish continuity between the DC output terminals of the generator, or turn on the power switch of the power tool. When the alternating current output terminals of the generator are electrically connected, the engine is automatically started because the starting circuit and the power supply are electrically connected and the starting circuit is effectively activated by the photocoupler.

On the other hand, when the manual switch is turned on, for example, if the welding rod has already touched the workpiece or the power tool has already been turned on, even if the photocoupler operates, there will be no connection between the starting circuit and the power source. is cut off, the starting circuit will not operate and the engine will therefore not start.

Kazuo-1-loneliness An embodiment of the present invention will be described below.

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

The engine (not shown) is fully automatically controlled by this engine control device, but when welding work is performed by the welding alternator G1 driven by the engine, the engine (not shown) is also driven by the engine. The control mode is somewhat different depending on the case where the power tool is operated by the AC generator G2 for the power tool. First, we will explain engine startup, idle, high speed operation, low speed operation, and stop in the case of welding. S-ru.

Turn on the engine key switch S1 and turn on the manual switch S2 for manual-automatic mode selection from the neutral position to the automatic side (lower side in the drawing). In this state, hold the welding rod holder (not shown).
This is done by bringing the welding rod held by the welding rod (which is connected to one or more negative electrodes of the DC electrode that rectified the alternating current of the alternator G1) to the workpiece to be welded, and then both electrodes W
1. Momentarily short-circuit W2. The b contact X8. of the relay X8 is connected to the negative electrode W2. A light emitting element of the first photocoupler C1 is connected through a resistor and a resistor, and a relay X12 is connected to the light receiving element.

This light receiving element is connected to the automatic side of switch S2.

Therefore, when the electrodes wl and w2 are short-circuited, the photocoupler C1 operates, turning on the relay X12 and closing its a contact X121. 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 switch 31. The DC voltage of battery B is applied via S2. Relay X14 maintains itself by closing its a contact X141. And relay X
By closing the a contact X131 of 13, the buzzer B
Z is activated, the engine heater H is activated to preheat the engine, and the timer T4 is activated, and the a contact T4. is closed, and at this time, since the a contact X132 of relay X13 is closed, relay X7
is turned on, and its a contact X7. is closed, the engine starter S is activated, and the engine starts. In other words, when the welding rod momentarily contacts the workpiece,
When a warning is issued by the buzzer BZ, the engine is preheated and automatically started after the time set by the timer T4.

In this case, when the welding rod contacts the workpiece, the current flowing between the electrodes w, w2 has large fluctuations, but the relay X12 is electrically connected to the electrodes w1 and w2 by the photocoupler C1. Because it is insulated,
It turns on precisely, and by simply bringing the welding rod into momentary contact with the workpiece, the engine can be started remotely, automatically, and reliably at the work site.

(idling) This is how the engine starts (runs at low speed when starting)
Then, both alternators Gl.

G2 and Guina motor D are driven, and relay X8 is turned on by the voltage of Guina motor D, and its a contact X
84 closes, relay XD turns on, and its b contact XD
1 opens 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 Wi and w2. This short circuit causes current to flow through the primary terminal P of the alternator G1, 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 current sensor CT and a slight voltage is generated, it is amplified and applied to second photocoupler C2, so this photocoupler operates, turning on relay RXI and closing its a contact RXl+. At this time, since the a contact X83 of the relay X8 is already closed, the relay X1 is turned on and its contact X11 is closed. At this time, since the a contact T51 of the timer T5 is already closed,
Relay X3 is turned on, its a contact X31 is closed, and relay X3 is self-holding, high-speed solenoid Ll is energized, the engine speed change mechanism is switched, and the engine shifts to high-speed operation.

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

Both electrodes Wt
, 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), and the b contact RB is turned on.

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 0, the third photocoupler C3 connected thereto is turned off, relay RX2 is turned off, and its b contact RX21 is closed. At this time, since the a contact RX12 of the relay Rx1 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 object to be welded for the time set by the timer T1 (approximately 2 seconds), the timer TI closes its a contact T12 to hold itself, and its b contact T1. This activates the buzzer BZ, turns off the relay X3, opens its a contact X31, deenergizes the high-speed operation solenoid L1, and returns the engine to the low-speed operation state.

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 a set time, its a contact T121 is closed and its b contact T122 is opened, and the relay is activated. X3 is turned off and 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, the Va Contact T131 closes, relay R1 also turns on, and the engine stops.

When relay R1 self-holds, its b contact R12 opens and relay X7 is disconnected from battery B, so starter S does not operate even if the welding rod contacts the workpiece. Therefore, the engine is prevented from restarting during the above-mentioned stop operation.

When relay R1's a contact R1+ closes, timer T3 also operates, and after a set time (approximately 5 seconds), its b contact T31 opens and relay R1 is turned off, and b contact T32 opens and relay X14 is also turned off. Then, the closed a contact X
142 opens, the power relay XE turns off, and the a contact XEl, which is the DC power switch, opens and returns to its original state.It is used for engine preheating, starting, high-speed operation, low-speed operation,
All stopping operations can be controlled consistently and fully automatically by the simple operation of bringing the welding rod into contact with the workpiece, and can also be controlled remotely by the welder himself at the work site as desired.

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 micro switch S6 is turned on, and the manual switch S for manual/automatic mode selection is turned on.
2 is set to the automatic side and turned on, this manual switch 32. Current from the battery B flows through the light emitting element of the first photocoupler C1 via the microswitch S6, turning on the relay X12 and closing its a contact X121, activating the buzzer BZ and turning on the safety relay XF. , its a contact XF is closed, the relay XF is self-holding, and its b contact XF2 is open (therefore, the relay It does not start even if it comes into contact with the work to be welded. To release this state, set the clutch to neutral, then open the release push button switch S7 to release the self-holding of relay XF.

Further, when the manual switch S2 is turned on to the manual side, the relay xE is turned on and its a contact XE is closed, but when the micro switch S6 is turned on, the b contact T6 of the timer T6 is turned on. Current from the battery B flows through the first photocoupler C1 via the microswitch S6,
Same as when set to automatic side, 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), whether the manual switch S2 is set to the automatic side or the manual side, the b contact T61. Since Te3 is open, relay XF is not turned on, p', so timer T6
When the welding rod is momentarily brought into contact with the object to be welded after the set time has elapsed, the starting circuit 3 is activated as described above, and the engine is started.

On the other hand, when the manual switch S2 is turned on to the automatic side or the manual side, if the welding rod is already in contact with the workpiece, the first photocoupler C1 is activated, the buzzer BZ is activated, and the b of the timer T6 is activated. Since contact T61 has not yet opened, safety relay XF is turned on, and as described above, power supply relay Booting is prevented.

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

,i! When the engine key switch S1 is turned on and the manual switch S2 is turned on to the automatic side, the current from battery B flows through the b contact XA of relay XA. Kushiso 10
It reaches one electrode of the outlet E of the 0V AC power supply, and the ■ terminal of the three-phase 200V AC power supply via the b contact XA2 of the same relay XA. In this state, turn on the power switch of the power tool connected to the outlet L-H or the 3-phase 20
When the power switch of a power tool connected to 0V AC power terminals U, V, and W is turned on, the current from battery B passes through the b contact XA of relay XA to the first photocoupler C.
In order to enter the light emitting element of 1, relay X12 is turned on,
As in the case of welding described above, the engine is automatically started 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 OV power tool is turned on, the first photocoupler C1 continues to operate, so current flows to the relay X1 via the closed A contact X83 of the relay X8, and this relay turns on, and its a contact X1. closes, relay X3 turns on, and the engine shifts to high-speed operation as in the case of welding. A predetermined voltage is generated in alternator G2 due to high-speed operation of the engine, and this voltage turns on relay XA (a contact of relay X3
32 is already closed) and its b contacts Xa1 to X
Since A4 opens, the exchange routes of 100■ and 200■ and 1
It is isolated from the 2V DC path. In addition, timer TA operates and after a set time (approximately 2 seconds), its a contact TAI closes, relay XB turns on, and its a contact XB closes.
100V single-phase AC voltage, U- to terminal 〇-W of AC power supply
A 200-inch three-phase AC voltage is applied to V-W, and a 100-inch or 200-inch electric tool connected thereto is driven.

In this state, a current flows through the path leading to terminal 0 or W, and is detected by the current sensor CT, causing the second photocoupler C2 to operate and relay RXI to be 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 0 and W, the second photocoupler C2 becomes inactive and the 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 X12 closes (
At this time, the a contact RB2 of the relay XB is closed because the welding work is interrupted), the timer TI2 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 TI2, 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 engine will not automatically shift to low speed operation because timer TI2 will not operate.

(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 closes, the relay R1 self-holds as described above, the stop solenoid L2 is energized, and the engine automatically stops.

(Safe operation) When the manual switch S2 is turned on to the automatic or manual side, if the power switch of the 100V or 200V power tool is already turned on, the first The photocoupler C1 operates to activate the buzzer BZ, and the safety relay XF is turned on, thereby cutting off the connection between the starting circuit 3 and the battery B, thereby preventing the engine from starting.

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 20OV three-phase AC power supply, and in that case, the engine will be controlled in the same way as above. be done.

As described above, according to the present invention, when the manual switch is turned on, the welding rod is already in contact with the workpiece, or the power switch of the power tool is already turned on. Alternatively, if a microswitch operated by the car's clutch is turned on, the starting circuit is cut off from the power source, preventing the engine from starting accidentally.

In addition, in order to operate the starting surface* and safety relay indirectly via a photocoupler, the current that flows when the welding rod contacts the workpiece, the current that flows when the power switch of the power tool is turned on, and the micro switch. Even if the current that flows when the engine is on is different, it is possible to accurately perform the function of disconnecting the starting circuit from the power source and the function of starting the engine.

[Brief explanation of the drawing]

The drawing is an electrical circuit diagram showing an embodiment of the present invention. 3...Start circuit, S2...Manual switch, B
...Battery, XE...Power relay, S6...
Micro switch, C1... Photocoupler, T6...
Timer, XF...safety relay. Tokukai Sho GO-IG46G3 (6)

Claims (1)

[Claims] 1. In an engine generator that generates DC or AC voltage between DC output terminals or AC output terminals by operating the generator with the engine, when the starting circuit that starts the engine and the manual switch are turned on. A power supply relay that is energized to provide continuity between the starting circuit and the power source, and the starting circuit that operates when continuity is established between the DC output terminals or AC output terminals or when a specific switch is turned on. a photocoupler that activates the power supply, a timer that operates for a set time when the manual switch is turned on, and a safety relay that energizes and de-energizes the power supply relay when the photocoupler operates while the timer is operating. A safety device for an engine generator, characterized by comprising: