JP2001018063A - Engine-driven generator for welding having ac electric source - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an engine-driven generator for welding with reduced noise and an improved fuel cost. SOLUTION: The engine-driven generator for welding is provided with a generator G which is driven by an engine E having a governor EG and supplies the output for welding and AC output, a welding output circuit REC2, CH and an AC output circuit REC1, IV and further has an AC electric source which drives the generator at a high speed at the AC output time and drives it at the speed in accordance with the output at the welding output time. Moreover, this generator is provided with a commander which forms command signals in each stage corresponding to at least three stages including an idle driving stage in accordance with the power of the necessary welding output, an AC load detecting circuit C1 and an actuator AT which forms a control signal for adjusting the governor corresponding to the command signal from the commandor and the detected signal from an AC load detecting circuit and adjusts the governor according to the control signal from a control circuit AC preferentially responding to the detected signal from the AC load detecting circuit.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine-driven welding generator that generates an AC output together with a welding output, and more particularly to an engine-driven welding generator that is driven at a rotational speed corresponding to the magnitude of a welding current of the welding generator. .

[0002]

2. Description of the Related Art An engine-driven welding generator that generates an AC output as a working power supply in addition to a welding output is widely used.

In this case, a constant current output at a set current value is required in terms of welding output. Minute welding output is taken out, and welding related work is carried out for 7 minutes. Therefore, if only the welding output is to be taken out, the engine only needs to be operated normally for 30% of the time and idle at 70% for a low speed.
Then, the operation speed is changed in accordance with the change in the required welding power being large or small according to the content of the welding operation.

On the other hand, since it is necessary to continuously output the AC output, it is necessary to continuously operate the engine, and the operation may be stopped when unnecessary.

[0005] Therefore, it can be said that it is reasonable to operate the engine in such a manner as to match the output utilization status of the two types of generators.

[0006]

Here, the engine-driven welding generator is often used in an environment where there is a party such as a construction site and other people.
We need to pay attention to the noise problem. It is also necessary to improve fuel efficiency as a general problem in engine driving equipment.

[0007] Therefore, it is necessary to optimize the operation of the engine-driven welding generator while taking noise and fuel consumption into consideration.

The present invention has been made in consideration of the above points, and has as its object to provide an engine-driven welding generator that can reduce generated noise as much as possible and improve fuel economy as much as possible.

[0009]

According to the present invention, a generator driven by an engine having a governor to form a welding output and an AC output, and a welding output from the generator are rectified. A welding output circuit for supplying the welding power to the welding output terminal, and an AC output circuit for converting the AC output from the generator to an AC output of a predetermined frequency and supplying the AC output terminal to the AC output terminal. In an engine-driven welding generator having an AC power supply which is operated at high speed and operates at a speed corresponding to the output during welding output, at least an idle operation stage is included for each of the required welding output levels determined by the operation. A command device that forms a command signal for each of the three stages, an AC load detection circuit that detects that the output of the AC output circuit is occurring, and forms a detection signal; A control circuit for forming a control signal for adjusting the governor according to a command signal from a command device and a detection signal from the AC load detection circuit, and preferentially responding to the detection signal from the AC load detection circuit And an actuator for adjusting the governor according to a control signal from the control circuit.

[0010]

FIG. 1 shows an overall configuration of an embodiment of the present invention. As shown in FIG. 1, the alternator G driven by the engine E produces outputs for two uses. One of them is DC-converted by the rectifier REC1 and then applied to the inverter IV to be converted into an AC having a predetermined frequency and sent out as an AC output. And the current transformer
Inverter IV detected by CT1 and current detector DET1
Based on the output current of the inverter IV, the inverter control circuit C1 controls the inverter IV to handle a short circuit. The output of the current detector DET1 is provided to the relay L5. Relay L
5 is a slowdown switch S connected in series to the key SW.
D also provides an energizing current.

The other of the two outputs of the AC generator G is converted to DC by the rectifier REC2 and then converted to a chopper CH.
And is sent out as welding output. And
Based on the output current of the chopper CH detected by the current transformer CT2 and the current detector DET2 and the current command based on the resistance value of the variable resistor VR, the output of the chopper CH is controlled by the chopper control circuit C2 at a constant current. The resistance value of the variable resistor VR is VR
Is detected by the VR position detection circuit VRD as a value representing the rotational position of the relay, and is used for energizing the relays L3 and L4.

The contact output by the energization and de-energization of the relays L3 and L4 is combined with the contact output of the relay L5 and given to the actuator controller AC as high-speed, medium-speed, and low-speed commands to control the engine speed. Will be

The speed control of the engine E is performed by the cooperation of the actuator controller AC and the actuator AT. The actuator controller AC has a key
High speed, medium speed and low speed command signals are provided by contact outputs of relays L3-L5 connected in series to SW.

The detection output of the current transformer CT1 is used as a priority control signal for operating the engine at a high speed, and is used as a priority control signal.
The detection output of No. 2 is used as a signal for changing the speed of the engine E stepwise in accordance with the welding operation. As long as the detection output of the current transformer CT1 is generated, priority is given to stably generating the AC output, and the engine E is set to the high-speed operation state.

On the other hand, when there is no detection output of the current transformer CT1 and only the detection output of the current transformer CT2, the operation control of the engine E according to the welding current is performed. Therefore, the operation of the engine E is performed at the selected speed in the speed range from the high-speed operation to the low-speed idling operation. As described above, the operating speed of the engine E depends on the setting position (set resistance value) of the variable resistor VR.
It is determined to be one of three low speed stages.

The variable resistor VR is used to set a welding current by selecting the resistance value. In this case, an arbitrary current value is specified in a range of 15 to 250 A. This current range is divided into three regions, 15-100A, 100-180A, and 180-250A, and is associated with the engine speed, low speed, medium speed, and high speed for each region.

For controlling the speed of the engine in the three engine speed ranges, the DC motor M of the actuator AT is rotated forward or backward, and the pulley PL is rotated in response to the rotation, and is connected to the lever of the engine governor EG. The rotation speed of the engine E is changed in three stages by changing the cable feeding length.

In order to control the forward and reverse energization of the DC motor M, three contact sets PC-P1, P-
C-P2 and PC-P3 are opened and closed. When the relays L1 and L2 provided in the actuator controller AC are switched and energized in accordance with the opening and closing of these three contact sets,
Energization of the DC motor M in the forward and reverse directions is performed, and the DC motor M rotates forward or reverse.

FIG. 2 is an explanatory diagram showing the operation principle of the actuator AT in FIG. 1 using a simplified configuration. The actuator AT operates the pulley PL. A cable connected to the engine governor EG is wound around the actuator AT. By changing the rotation angle, the feeding length of the cable is changed to reduce the speed of the engine E. To change it.

Further, for the control operation, FIG.
By the forward / reverse rotation of the DC motor M with a speed reduction mechanism provided below, a force for rotating clockwise or counterclockwise in the drawing is given.

On the upper surface of the pulley PL, a conductor pattern CP, which is schematically shown, is formed. Contacts are separated from and separated from the conductor pattern CP, and the relays L1 and L2 connected to the respective contacts are connected to each other. Energize and de-energize. As for the contacts, when the pulley PL is turned in the direction of the arrow in the figure, one contact comes into contact with the conductor pattern CP, and the other contact moves away from the conductor pattern CP. As a result, the relay L1 is energized, and the contact point of the relay is switched to the position indicated by the broken line (2) in FIG.
Switches to the position indicated by the broken line (3) in FIG.
, The motor M rotates forward, and stops when it is separated from one of the contacts.

When the pulley PL is turned in the direction opposite to the direction indicated by the arrow, the other contact comes into contact with the conductor pattern CP, and one contact moves away from the conductor pattern CP. As a result, the relay L1 is deenergized and the relay L2 is energized, so that the contact of the relay L1 is in a solid line state, the contact of the relay L2 is in a broken line state, and the motor M rotates in the reverse direction.

Although not shown in FIG. 2, the actuator AT changes the payout length of the cable connected to the engine governor EG to three stages so that the engine performs each operation of high speed, medium speed and low speed idling. Works.

FIG. 3 shows a scale configuration of the variable resistor VR schematically shown in FIG. As shown in FIG. 3, the variable resistance VR can be set to a variable range of 15 to 250 A for the welding current, and this range corresponds to three stages of engine speed. That is, 15-10
0A range is low speed range (2200rpm), 100-1
80A range is medium speed range (2400rpm) and 1
The range of 80 to 250 A is a high speed region (3000 rpm), and the actuator AT in FIG. 2 is operated by setting the welding current, so that the operation speed is automatically determined.

FIG. 4 shows the contact relationship between the conductor pattern CP on the pulley PL schematically shown in FIG. 2, the common contact PC, and the three individual contacts P1-P3. The conductor pattern CP has a semicircle (180 degrees) distribution pattern disposed on the outside, and a semicircle distribution pattern, which is also a semicircle distribution pattern.
It is a combination of a pattern arranged inside so as to overlap by about -60 degrees.

FIG. 4A corresponds to the low-speed idling operation region, and the common contact PC is connected via the conductor pattern CP.
And only P2 in the individual contacts makes contact. FIG. 4 (b)
Corresponds to the medium speed region, and the common contact PC and the individual contacts P1, P
2 comes into contact. FIG. 4C corresponds to the high-speed region, in which the common contact PC and the individual contacts P1 and P3 are in contact.

FIG. 5 shows a configuration of the actuator controller AC shown in FIG. 1 and a configuration related to the actuator AT.

As shown in FIG. 5, the engine governor E
To adjust the payout length of the cable connected to G,
The pulley PL is rotated forward and backward by the motor M.
The forward and reverse rotation of the motor M is performed by energizing and deenergizing the relays L1 and L2. The energization and de-energization of the relays L1 and L2 are performed by a circuit including transistors Q1 to Q4, a logic circuit LC controlling these transistors, and an off timer OT.

Then, the direction of energization to the motor M is switched forward and reverse by the switching connection operation of the relay switching contacts L1 and L2.
By rotating the pulley PL to adjust the cable feeding length, the speed of the engine is changed into three stages of low speed idling, medium speed and high speed. This control operation itself will be described later with reference to the flowchart of FIG.

The actuator controller AC starts when the key SW is turned on, and stops when the key SW is turned off. When the key SW is turned off, the off timer OT sets the relay L2
For a predetermined period of time to return the engine governor EG to a low speed state and stop. This allows
The next time the engine starts, the engine governor is in low speed,
From there, the necessary speed-up operation is performed.

FIG. 6 is a table showing each input for each of the operation conditions 1 to 7 of the actuator controller shown in FIG. 5 and a relay operation corresponding thereto.

The operating conditions 1 to 7 are the following seven (1) to (7).

(1) When the key SW is off and the engine is stopped (2) When the variable resistor VR is at a position other than low speed (3) When the variable resistor VR shifts from high speed to medium speed (4) When the variable resistor VR is When shifting from load to no load at high speed position (5) When variable resistor VR detects load at high speed position (6) Variable resistor When shifting from load to no load at medium speed position (7) Variable resistor VR is medium When the load is detected at the high speed position, the input of the welding output circuit is key SW, variable resistance VR
8 contacts of relay L3-L5 at middle speed, high speed and low speed position, welding load detection signal by current detector DET2, and contact output PC-P1, PC-P2 and PC-P3 of actuator AT Are two outputs for turning on and off the relays L1 and L2.

The relay L5 is operated by the current detector DET1 to forcibly give priority to the AC output operation.

The reference numerals in the table in FIG. 6 correspond to those in FIG.

FIG. 7 is a flowchart showing the operation of the above embodiment. The overall operation is controlled by an actuator controller AC (FIG. 1) whose internal configuration is shown in FIG.

If a start command is given to the actuator controller AC by turning on the key SW (S1), it is first determined whether the slowdown switch SD is on or off (S2).

If it is off, the operation shifts to step S21 because it is not the load operation. In step S21, the relay L1
Energize. As a result, the motor M rotates forward and the pulley P
L is rotated clockwise in FIG. 2 (step S2).
2). The relay L1 is energized until the conductor pattern CP on the upper surface of the pulley PL contacts the contacts PC and P3. While the forward rotation of the motor M continues, it is determined in step S23 whether or not the contact points PC-P3 are in contact with each other, and the motor M continues to rotate forward because the relay L1 is energized until the contact is made. As a result, the payout length of the cable connected to the engine governor EG is shortened, and the engine operates at an increased speed.

Next, a contact PC using the conductor pattern CP
When −P3 becomes conductive, the relay L1 is deenergized in step S24, and then the motor M stops (step S25). Then, in step S10, the engine governor EG operates the engine E at a speed determined in that state, that is, at a high speed. Then, high-speed operation is continued, and an operation command by the next operation is waited.

Here, returning to step S2 again and continuing the description, the operation is performed when the slowdown switch is turned on. In this case, the operation is basically a variable speed operation. However, in this embodiment, when an AC load occurs, the AC output operation is preferentially performed.

Therefore, even if the slowdown switch is on and the welding operation is being performed, the process proceeds from step S2 to step S3 to check for the presence of an AC load signal from the current transformer CT1 (FIG. 1). The process proceeds to step S21 to operate at high speed, and if not, the process proceeds to step S4.

In step S4, the presence or absence of a welding load signal from the current transformer CT2 (FIG. 1) is checked.
The operation shifts to low speed idling operation after 41. That is, the relay L2 is energized in step S41, and the motor M is rotated reversely (S42).

As a result, the pulley PL in FIG. 2 rotates in the counterclockwise direction in the figure, the length of the cable connected to the engine governor EG becomes longer, and the engine speed decreases. This operation is performed by the contact PC in step S43.
The connection is continued as long as the connection between -P1 is established. When the connection is lost, the relay L2 is turned off (S44), and the motor M is stopped (S45). At this time, the engine governor E
G is in a state of low-speed idling operation. Then, the low-speed operation is continued, and the next command is waited.

Returning to step S4, a case where there is a welding load signal will be described. The welding load signal is the current transformer CT2
The speed is selected according to which speed region (current region) the variable resistor VR indicates in Steps S5, S6 and S7. First, in the case of a low-speed region (a region of a current of 15 to 100 A), the operation from step S41 is performed. This is as described above.

In the case where the resistance value indicates a medium speed region (a region where the current is 100 to 180 A), the operations of steps S61 to S70 are performed. First, in step S61, it is determined whether or not the contact PC-P1 is off. If it is off, the relay L1 is turned on (S62), the motor M rotates forward (S63), and if the contact PC-P2 is turned off (S64), the relay L1 is turned off (S65). .
Then, the motor M stops (S66), and the engine governor EG is adjusted at the stop position at this time (S1).
0).

On the other hand, when the contact point PC-P2 is on,
In step S67, the relay L2 is turned on, and the motor M is rotated in the reverse direction (S68). This is the contact PC-
The operation continues until P2 is turned on (S69), and when turned on, the relay L2 is deenergized (S69), and the motor M stops (S66). Thus, the engine governor EG causes the engine to operate at a medium speed.

Then, in the high-speed region (current of 180 to 250 A)
Region), the process proceeds from step S7 to step S2 described above.
Then, the operation proceeds to S1 and the operations of S21 and subsequent steps are performed, and a high-speed operation state is set.

When the load is not detected due to the slowdown operation, the operation is all idling.

[0049]

As described above, the present invention relates to a generator which provides an AC output in addition to a welding output and which has a slowdown function, is provided with at least three of low speed idling operation, medium speed operation and high speed operation. By operating in the speed range, it is possible to minimize noise and fuel consumption without causing the engine to operate at excessive speeds while providing the required output.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing the overall configuration of an embodiment of the present invention.

FIG. 2 is an explanatory view showing the operation principle of the actuator used in the embodiment of FIG.

FIG. 3 is an explanatory view showing a dial display unit of the actuator shown in FIG. 2;

4 (a) to 4 (c) are explanatory diagrams showing a relationship between a conductor pattern used for the actuator shown in FIG. 2 and a contact point.

FIG. 5 is an explanatory diagram showing an internal configuration of the actuator controller shown in FIG. 1;

FIG. 6 is a table showing input conditions of the actuator controller shown in FIG. 6 and output states of relays L1 and L2 corresponding thereto.

FIG. 7 is a flowchart showing the operation of the actuator controller shown in FIG. 5;

[Explanation of symbols]

 E Engine G Generator EG Engine governor AC Actuator controller AT Actuator M DC motor L1-L5 Relay REC1, REC2 Rectifier CT1, CT2 Current transformer DET1, DET2 Current detector C1 Inverter control circuit C2 Chopper control circuit VR Variable resistance VRD Variable resistance Position detection circuit PL Pulley SD Slow down switch OT Off timer Q Transistor

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3G093 AA17 AB05 BA19 BA32 CA10 CA11 DB20 EA05 EC02 4E082 BA02 BB01 CA04 EA13 EC13 ED01 EF07 5H590 AA02 AA06 CA07 CC01 CD01 CD03 CE06 EA07 EB03 EB21 FA01 FC02 FC04 GA03 GB03 JB18

Claims (3)

[Claims] 1. A generator driven by an engine having a governor to form a welding output and an AC output, a welding output circuit for rectifying a welding output from the generator and supplying the rectified welding output to a welding output terminal. An AC output circuit for supplying an AC output from the generator to an AC output terminal, wherein the generator is operated at a high speed during the AC output, and is operated at a speed corresponding to the output during the welding output. An engine-driven welding generator having a power supply, wherein a commander for forming a command signal in each of at least three stages including an idle operation stage for a required welding output level determined by an operation; An AC AC load detection circuit that detects that an output is occurring and forms a detection signal; and responds to a command signal from the command device and a detection signal from the AC load detection circuit. A control circuit that forms a control signal for adjusting the governor and preferentially responds to a detection signal from the AC load detection circuit; and an actuator that adjusts the governor according to the control signal from the control circuit. An engine-driven welding generator, comprising: 2. The generator for engine-driven welding according to claim 1, further comprising: a welding load detection circuit configured to detect that an output of the welding output circuit is generated to form a detection signal, and the control circuit includes: An engine-driven welding generator adapted to respond to a detection signal of the welding load detection circuit. 3. The engine-driven welding generator according to claim 1, wherein said command unit generates three-stage command signals corresponding to a large, medium, and small required welding output. Generator.