JPH0127824B2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to an engine welder in which a generator is driven by an engine for arc welding with a welding rod, and particularly in an engine welder in which the engine is rotated at high speed during welding work and rotated at low speed when welding work is interrupted. The present invention relates to an engine control device that controls the operation of an engine.

[Conventional technology]

Conventionally, as this type of control device,
As is known from Publication No. 24121, when an arc connection is made between the welding rod and the workpiece (base metal), the engine high speed operation device is activated to increase the engine speed from low speed to high speed. On the other hand, when the arc connection is interrupted, the opening operation of the engine high-speed operating device is delayed for a certain period of time;
There has been provided an engine that automatically switches the engine from high speed rotation to low speed rotation when the arc connection is interrupted for a certain period of time, thereby achieving an energy saving effect and a noise prevention effect.

[Problem to be solved by the invention]

However, in this case, each time the welding work is temporarily interrupted, the engine automatically switches from high-speed rotation to low-speed rotation, so the operation to return to high-speed operation must be performed frequently.
The return operation is performed by bringing the welding rod into contact with the workpiece (grounding) and passing an arc current of a specified value or higher. However, if the workpiece is painted or rusted, The arc current does not flow easily, and the return operation often takes time. In such cases, the object to be welded is struck with the tip of the welding rod to remove paint and rust, but this also peels off the coating material that coats the welding rod, and the tip of the welding rod becomes more and more ferrous. Because the core is exposed,
The welding rod becomes firmly welded to the workpiece, and the return operation becomes increasingly difficult, a vicious cycle that repeats. In welding work, workers require the following:
The ease of re-arc-generating operations for re-starting welding operations is particularly useful in locations with poor working conditions, such as high places with unstable footing. Therefore, it is the worker's intention to maintain the high-speed rotation state without switching to a low-speed rotation, but automatically reducing the speed to a low speed against one's will is a problem for work management and work efficiency. This is undesirable, and in the conventional system, the already troublesome return operation as described above must be performed frequently, resulting in a significant decrease in work efficiency. In addition, in the past, the engine was started and stopped by manually turning on and off a manual switch provided on the engine body, so when starting or stopping the engine, it was necessary to go to the installation location of the engine body. In addition, workers carrying welding rods were unable to start and stop the engine at any time at the work location. The purpose of the present invention is to start the engine, high speed rotation,
All operations, including low-speed rotation and stopping, are controlled consistently and fully automatically by the simple operation of touching the welding rod to the object to be welded and grounding it, and the welding operator can control it remotely and as desired at the work site. Our goal is to provide an engine control device that can.

[Means to solve the problem]

In the engine control device of the present invention, as shown in FIG. 1, the welding rod 6 connected to the welding rod holder 7 and held therein is in continuous contact with the workpiece W for more than the set time of the starting timer T4. Starting circuit 1 starts the engine using current from the battery when
, a welding relay X9 connected to the dynamotor D driven by the engine and energized by the current from it as it is driven; a switch section _X9 of this relay X9 and the welding rod holder. 7, and is activated when the relay X9 is turned on, the switch portion _X93 is closed, and the welding rod 6 is brought into contact with the workpiece W to be welded so that the arc current flows.
And, the switch part of this arc current detection means CRX
a circuit _{2 which is connected to CRX 1} and switches the engine speed from low speed rotation to high speed rotation using current from the battery when the arc current detection means CRX is activated and the switch portion CRX ₁ is closed; Switch part of current detection means CRX
An arc operating relay X0 connected to CRX ₁ and turned on when the switch CRX ₁ is closed, and a switch section X0 ₁ of this relay X0 and a switch section X9 ₃ of the welding relay X9 connected to the generator G. and the welding rod holder 7
When these switch parts X0 ₁ and X9 ₃ are closed, the voltage of the generator G is applied and the generator G is turned on, and when the welding rod 6 comes into contact with the workpiece W to be welded and the generator is short-circuited, the generator is turned off. the first relay X1, and the switch section _XO2 of the arc activation relay X0.
a second relay X2 that is connected to and turned on and off by opening and closing; connected to the switch section X1 ₁ of the first relay X1 and the switch section X2 ₁ of the second relay X2;
a low-speed switching timer T1 that operates when both of these are closed; a circuit 3 that switches the engine from high-speed rotation to low-speed rotation when the timer T1 operates for a set period of time; Switch part X1 ₂ of relay X1 and switch part X0 ₃ of the arc activation relay X0
The welding rod 6 is further connected to the workpiece W after the operation of the circuit 3 which changes the speed from the high speed rotation to the low speed rotation.
a stop timer T2 that operates when the first relay X1 continues to be turned off and its switch portion _X12 is closed, and the arc activation relay X0 is turned on and its switch _X03 is closed; The engine is equipped with a stop circuit 4 that stops the engine using current from the battery when T2 is activated for a set time. Further, from the time when the welding rod 6 comes into contact with the workpiece W to be welded as described above and the generator is short-circuited, electrical continuity is established between the stop timer T2 and the battery, and after the set time of the stop timer T2 has elapsed. The stop circuit 4 is provided with a switch section _T01 for cutting off the timer T2 from the battery.

[Operation] Therefore, first, if the welding rod 6 is brought into contact with the workpiece W for more than the set time of the starting timer T4,
A generator G is started by the engine, and a voltage is applied to the welding rod 6. In this state, when the welding rod 6 is momentarily brought into contact with the workpiece W and an arc current is applied, the engine automatically changes speed from low speed rotation to high speed rotation, and the voltage applied to the welding rod 6 from the generator G is rises. Perform welding work in this state. In addition, if the welding rod 6 is kept in contact with the workpiece W in a high-speed rotation state for a period longer than the time set by the low-speed switching timer T1, it will automatically return to the low-speed rotation state, and then continue for the time set by the stop timer T2. It will automatically stop if it is touched more than that.

【Example】

An embodiment of the present invention will be described in detail below based on the drawings. As shown in FIG. 1, this engine control device is broadly divided into a starting circuit 1, a high-speed operation circuit 2,
Consists of a low-speed operation circuit 3 and a stop circuit 4,
When the engine key switch 5 is turned on, a DC voltage from a battery (not shown) is applied via a fuse F. A welding rod holder 7 holding a welding rod 6 is connected to the engine control device and the positive electrode (one output terminal) of the generator G via a cab tire cable 8, and the engine (not shown) is connected to the positive electrode (one output terminal) of the generator G. When the rod 6 is brought into contact with the workpiece W to be grounded, the four operations of starting, high-speed rotation, low-speed rotation, and stopping are fully automatically controlled, and these operations will be explained in sequence. Startup Connect the lead wire 8a drawn out from the engine control device to the workpiece W to be welded, and bring the welding rod 6 into contact with the workpiece W with the engine key switch 5 turned on. Then, the direct current from the battery passes through the B contact X9 ₂ of the welding relay X9, the cab tire cable 8, the welding rod holder 7, the welding rod 6, the workpiece W, and the B contact X9 ₁ of the welding relay X9. It flows into the starting circuit 1. As a result, the preheating plug P is heated, and the engine decompression operation solenoid SR4 is energized to perform decompression (not shown).
is operated. At the same time, timer T4 operates and after a set time, its a contact T4 ₁ closes, and the starting relay X5 turns on and its a contact T4 ₁ closes.
Relay X10 for protecting timer T4 is turned on and its a contact _X101 is closed, cell switch relay X11 is turned on and starter motor (not shown) rotates. At this time, the welding relay X9 is
The current from the battery is cut off by the action of diode _D1 , so it does not turn on. After this,
When the timer T5 expires, the a contact T5 ₁ closes, relay X6 turns on, and the b contact X6 ₁ closes.
When the decompression operation solenoid SR4 opens,
is turned off and decompression is restored, allowing the engine to start. Therefore, when the welding rod 6 is brought into contact with the workpiece W for a period longer than the time set by the starting timer T4, the engine is automatically started. When the engine starts, this causes the generator G
and the dynamotor D is driven, and the welding relay X9 is turned on by the DC current of the dynamotor D, and both b contacts X9 ₁ and X9 ₂ are opened.
The current flowing from the battery to the starting circuit 1 is cut off,
The engine becomes idle (rotating at low speed). High-speed rotation The welding rod 6 is brought into contact with the workpiece W to be welded while the engine is idling. At this time, since a predetermined voltage (for example, 24V) is applied to the welding rod 6 from the generator G and the a contact _X93 of the relay X9 is already closed as described above, the welding rod 6 and the workpiece W are connected. During this period, an arc current flows, and the current relay CRX, which is the arc current detection means, is turned on and its a contact CRX ₁
closes, relay X8 turns on, and its a contact
8 ₁ is closed and the high-speed switching solenoid SR1 is energized. When this solenoid SR1 is excited, the lever 9 is rotated by the electromagnetic force as shown in FIG.
0 slides along the guide tube 11 and is locked into the lock pawl 12. The sliding movement of the slider 10 pulls the engine throttle connected thereto, causing the engine to shift from low speed rotation to high speed rotation. When the slider 10 is locked as described above, the limit switch LS is actuated and opened by the slider 10, and the relay X8 is turned off and its a contact X8 is opened.
Since solenoid _SR1 is opened again, the high speed switching solenoid SR1 is demagnetized. When the engine rotates at high speed, the voltage applied to the welding rod 6 increases compared to when the engine is idling. For example, it increases from 24V to 84V. Perform welding work in this state.
During the welding work, the A contact of the current relay CRX
CRX ₁ is closed as described above, turning on the arc activation relay X0, its a contact X0 ₁ is closed and the first relay X1 is turned on, and its b contact X1 ₁ ,
Since _X12 is opened, the low speed operation circuit 3 and the stop circuit 4 are in a prohibited state in which they cannot operate. At this time, the b contact X0 ₂ (in the low-speed rotation circuit 3) of the arc activation relay X0 is opened, so the second relay X2, which will be described later, is not turned on. Low speed rotation The engine rotates at high speed as shown above and the generator G
Welding rod 6 with a voltage of 84V applied from
is brought into continuous contact (welding) with the workpiece W to be welded. When this contact is made, the two electrodes of the generator G are short-circuited and the voltage becomes 0, so the first relay X1 is turned off and its b contact X1 ₁ is closed. At this time, as described above, current relay CRX is turned on and its a contact CRX ₁ is closed, relay X0 is turned on and its a contact _X02 is opened, and second relay X2 is turned off and its b contact X2 ₁ is closed, the low speed switching timer T1 operates. If the welding rod continues to touch the workpiece W, that is, ground, for more than the set time (about 2 seconds) of the timer T1, the a contact T1 ₁ of the timer T1 closes and the relay
3 is turned on, its a contact _X31 closes, and the low speed switching solenoid SR2 is energized. As a result, as shown in FIG.
The locking state of the slider 10 is released, and the engine shifts from high-speed rotation to low-speed rotation. While the welding rod 6 is in contact with the workpiece W to be welded, the current relay CRX turns on and closes its a contact, so during this time the arc activation relay X0
remains on, closing its a contact X0 ₁ while opening its b contact X0 ₂ . When the welding rod 6 is separated from the workpiece W after the time set by the timer T1, the engine is in the low speed rotation state as described above, so the voltage applied to the welding rod 6 from the generator G is
It becomes 24V. Note that when the a contact T1 ₁ of the low speed switching timer T1 closes, the relay X3 turns on and its b contact X3 ₂ opens, so the high speed operation circuit 2
relay X8 will not turn on. However, within the set time of timer T1 (approximately 2
When the welding rod 6 is separated from the workpiece W to release the short-circuit state within seconds), the voltage applied from the generator G to the welding rod 6 increases. At this time, since the a contact X0 ₁ of the arc activation relay X0 is closed as described above, the first relay X1 is turned on again and its b contact X1 ₁ opens, and the a contact T1 ₁ of the timer T1 is Since it does not close, relay X3 does not turn on, and low speed switching solenoid SR2 is not energized, so the engine maintains a high speed rotation state. When the engine changes from high speed rotation to low speed rotation as described above, when the welding rod 6 is brought into contact with the workpiece W again to flow an arc current, the current relay CRX
is turned on, the high-speed switching solenoid SR1 is energized in the same manner as described above, and the engine again changes from low-speed rotation to high-speed rotation. Stop When the rotation speed changes from a high speed rotation state to a low speed rotation state, the off timer T0 is activated. The off-timer T0 performs an off-delay operation, and unlike a normal timer that performs an on-delay operation, it operates for a set time after the power is cut off to switch the contacts. There is a product name ``New Magic Timer'' manufactured by the company. Since this off-timer T0 is applied with a voltage from another output terminal of the generator G, the welding rod 6 is moved to the workpiece W as described above in a high-speed rotation state.
If welded to the electrodes of the generator G, a short circuit occurs between the two electrodes of the generator G.
For example, the voltage applied to off timer T0 is 100V
to 0V, and the off-timer T0 is activated.
When this operates, the a contact T0 ₁ will be approximately 5
It closes for a second and then opens again. This a contact T0 ₁
is closed, and both the B contact X1 ₂ of the first relay X1 and the A contact X0 ₃ of the relay X0 are closed due to the grounding of the welding rod 6, the stop timer T
2 is activated. The set time of this timer T2 is shorter than the off-timer T0, and is set to, for example, about 2 seconds. Therefore, if the welding rod 6 continues to be in contact with the welding rod 6 for about 2 seconds or more even after the transition from high-speed rotation to low-speed rotation (welding continues for about 4 seconds or more in total), timer T2 is activated.
A contact T2 ₁ closes. As a result, keep set relay KS is turned on, and both keep switches K ₁ and K ₂ are closed, and this state is maintained mechanically. At this time, relay X4 is simultaneously turned on and its b contact _X41 is opened, so relay X8 of high-speed operation circuit 2 is not turned on. keep switch
When _K2 is closed, relay X7 is turned on, its a contact _X71 is closed, stop solenoid SR3 is energized, decompression is activated, and the engine is stopped. On the other hand, when the keep switch _K1 is closed, the timer T3 is activated, and after the set time (after the engine has completely stopped), the a contact _T31 of the timer T3 is closed and the keep preset relay KL is turned on again. , and the keep switches K ₁ and K ₂ , which are kept mechanically closed as described above, open.
This turns off relay X7, demagnetizes stop solenoid _SR3 , and restores decompression. In the above embodiment, a contact type relay was used, but a non-contact type relay may be used.

【Effect of the invention】

As is clear from the above description, the present invention has the following effects. Engine startup, high-speed rotation, low-speed rotation, and stopping are all performed consistently and fully automatically by the simple operation of touching the welding rod to the workpiece and grounding, and the welder can do it himself at the work site. Can be controlled remotely and as desired. By keeping the welding rod in contact with the object to be welded for longer than the time set by the startup timer, the engine can be brought into a low-speed rotation state and automatically started. By making contact for a set time or longer, the engine can be automatically switched from a high speed rotation state to a low speed rotation state. Therefore, it is possible to start the engine and change gears according to the operator's wishes, and the gears are automatically changed every time the welding work is temporarily interrupted, eliminating the need for frequent return work, which is already troublesome. Compared to conventional products, it is possible to significantly improve work efficiency, and it has even greater energy-saving and noise-prevention effects. If the welding rod is brought into contact with the object to be welded for longer than the time set by the low-speed switching timer and then released, the engine is already in a low-speed rotation state, so it is safe. Even if the welding rod comes into contact with the workpiece during welding, the engine will not switch to the low-speed rotation state unless the contact continues for the time set on the low-speed switching timer, so careless switching can be avoided. It can be prevented. After shifting to low-speed rotation, the engine will not stop unless the welding rod continues to be in contact with the welding rod for a period longer than the time set by the stop timer, so that an inadvertent stop can be prevented.

[Brief explanation of drawings]

FIG. 1 is an electric circuit diagram showing an embodiment of the present invention;
FIG. 2 is an explanatory diagram showing the mechanical configuration of the engine operating section. 6... Welding rod, 7... Welding rod holder, W... Work to be welded, T4... Starting timer, 1... Starting circuit, D... Dynamotor, X9... Welding relay, CRX... Current Relay (arc current detection means), 2...High speed operation circuit, X1...First relay, X2...Second relay, T1...Low speed switching timer, 3...Low speed operation circuit, T2...Stop timer, 4... stop circuit.

Claims (1)

[Claims] 1. An engine capable of changing speed between high-speed rotation and low-speed rotation, and a generator G driven by the engine;
The welding rod holder 7 is connected to one electrode of the generator G, and the welding rod holder 7 holds the welding rod 6, while the other electrode of the generator G is connected to the workpiece W.
In the engine welder, which melts the welding rod 6 by passing an arc current between these welding rods 6 and the workpiece W, it is connected to the welding rod holder 7, and the welding rod 6 held therein is connected to the welding rod 6 to be welded. A starting circuit 1 is connected to a starting circuit 1 that starts the engine using a current from a battery when the object W is in contact with the object W for a period of time set by a starting timer T4, and a dynamotor D driven by the engine. A welding relay X9 is turned on by the current flowing therethrough, and is connected to the switch section X9 ₃ of this relay X9 and the welding rod holder 7, and when this relay X9 is turned on, the switch section X9 ₃ is turned on. Arc current detection means CRX that is closed and operates when the welding rod 6 comes into contact with the workpiece W to be welded and the arc current flows.
And, the switch part of this arc current detection means CRX
a circuit _{2 which is connected to CRX 1} and switches the engine speed from low speed rotation to high speed rotation using current from the battery when the arc current detection means CRX is activated and the switch portion CRX ₁ is closed; Switch part of current detection means CRX
An arc operating relay X0 connected to CRX ₁ and turned on when the switch CRX ₁ is closed, and a switch X0 ₁ of this relay X0 and a switch X9 ₃ of the welding relay X9 connected to the generator G and welding rod holder 7
When these switch parts X0 ₁ and X9 ₃ are closed, the voltage of the generator G is applied and the generator G is turned on, and when the welding rod 6 comes into contact with the workpiece W to be welded and the generator is short-circuited, the generator is turned off. the first relay X1, and the switch section _XO2 of the arc activation relay X0.
a second relay X2 that is connected to and turned on and off by opening and closing; connected to the switch section X1 ₁ of the first relay X1 and the switch section X2 ₁ of the second relay X2;
a low-speed switching timer T1 that operates when both of these are closed; a circuit 3 that switches the engine from high-speed rotation to low-speed rotation when the timer T1 operates for a set period of time; Switch part X1 ₂ of relay X1 and switch part X0 ₃ of the arc activation relay X0
The welding rod 6 is further connected to the workpiece W after the operation of the circuit 3 which changes the speed from the high speed rotation to the low speed rotation.
a stop timer T2 that operates when the first relay X1 continues to be turned off and its switch portion _X12 is closed, and the arc activation relay X0 is turned on and its switch _X03 is closed; It is equipped with a stop circuit 4 that stops the engine with the current from the battery when T2 operates for a set time, and when the welding rod 6 comes into contact with the workpiece W to be welded as described above and the generator is short-circuited. An engine characterized in that the stop circuit 4 is provided with a switch section _T01 that connects the stop timer T2 and the battery and disconnects the timer T2 from the battery after the set time of the stop timer T2 has elapsed. Welda's engine control device.