JPH0373388B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an automatic welding device used for horizontal fillet welding of a box structure, particularly a square structure of a ship.

[Conventional technology]

Conventionally, for example, fillet welding of a square structure of a ship has been carried out manually or semi-automatically by gravity welding, for example. Additionally, in general, a ship's grid structure has two lines along the longitudinal direction of the ship.
The elevation part that consists of a side and two sides perpendicular to the longitudinal direction of the ship, and that forms each side, has a wall thickness that is different on the side along the longitudinal direction of the ship and the side perpendicular to the longitudinal direction of the ship. , the orthogonal side is set to be thicker than the longitudinal side. Therefore, the above-mentioned welding is performed under welding conditions depending on each side.

[Problem that the invention seeks to solve]

Naturally, the manual welding described above requires the operator to perform the welding work all the time.
This contradicts the demand for labor-saving, and semi-automatic welding requires a rotating device in the square structure, a forward/backward movement device, and a computing device such as a microcomputer, which inevitably increases the complexity and size of the device. There was a problem.

The present invention has been made to solve these problems, and it is an object of the present invention to provide an automatic welding device that is simple and compact.

[Means for solving problems]

The automatic welding device according to the present invention includes a magnet,
A front wheel and a rear wheel are attached to a welding cart, and the front wheels and the rear wheels move along the grid on the inner surface of the vertical surface by a magnetic force acting between them and the vertical surface of the grid structure, and the front wheels are used as driving wheels, and The notches are unevenly distributed around the welding cart to change the distribution of magnetic force on the circumference, and in an automatic welding device with a rear wheel as a follower wheel, it is installed on the front of the welding cart and is used during welding. a first switch that outputs a first signal when the line is not in contact with the wall in front of the line, stops the first signal and outputs a second signal when the line contacts the wall; and a side surface of the welding cart. The third wheel is installed between the front wheel and the rear wheel in the
a second switch that outputs a signal and stops the third signal if there is no contact, and a second switch that is installed on the rear surface of the welding cart and is not in contact with the wall behind the welding line to be welded. A third switch outputs a fourth signal when the switch contacts the third switch, and stops the fourth signal when the switch contacts the third switch, and outputs a welding permission signal when the first, third, and fourth signals are input together. a welding permission means that stops outputting the welding permission signal when the output of any one of the first, third, and fourth signals stops; and when the second signal is input, the welding cart is moved to the corner of the square structure. a position detecting means that notifies that the welding point has been reached, and then notifies that the next corner has been reached when the second signal is input; and a position detecting means that enters a reset state when the last corner is reached; and the welding permitting means. When a welding permission signal is input from the position detecting means, the welding power source unit reads preset welding conditions based on the position from the position detection means and supplies a discharge current according to the conditions.

[Effect]

In this invention, even if the corners of the square structure, that is, the vertical surfaces of the workpiece to be welded are structural parts that are perpendicular to each other, the front wheels can be moved along the perpendicular vertical surfaces using changes in magnetic force. While moving, the first switch detects the front wall and changes the welding conditions to weld the next weld line, so welding of different leg lengths can be performed automatically.

〔Example〕

FIG. 1 is an explanatory rear view of a welding cart according to an embodiment of the present invention, and FIG. 2 is an explanatory top cross-sectional view thereof. In the figure, 10 is a welding truck, and 11 is a front wheel attached to the welding truck 10. This front wheel 1
1 is a material with high magnetic permeability, as shown in FIG.
For example, iron pieces 12, 12 and a magnet 13 sandwiched between them
It consists of This iron piece 12 has a notch 1
2a to 12d are provided, and therefore the front wheel 1
The distribution of magnetic force around the circumference of 1 fluctuates.

14 is a motor, 15 is a reduction gear, and the gear 14a provided on the shaft of the motor 14 is connected to the gear 1 provided on the front wheel 11 via the reduction gear 15.
1a, the rotational motion of the motor 14 is transmitted to the front wheels 11, and the front wheels 11 function as driving wheels.

A rear wheel 16 is attached to the welding cart 10, and its structure is almost the same as the front wheel 11, but there is no notch and it functions as a follower wheel. 17 is a caster, and although only one is shown, it is a welding cart 1.
One each is attached to the front and rear parts of the 0.

20 is a nozzle, which is arranged opposite to the welding point A. 21 is a CO ₂ long torch, 22 is a holder,
And 23 is a support member that supports the holder 22.

SW1 is a first switch, that is, a detection switch, which is a limit switch attached to the front of the welding truck 10, SW2 is a second switch, that is, a limit switch, which is installed between the front wheels 11 and rear wheels 16 of the welding truck 10, and SW3 is a welding truck 10 is a third switch or limit switch mounted on the rear surface of the switch.

To explain this in more detail based on the block diagram of the control device shown in Fig. 4, the detection switch SW1 outputs the first signal 61 when the wall in front of the welding line during welding is not in contact, and Then, the first signal 61 is stopped and the second signal 62 is output.

The limit switch SW2 generates a third signal 63 when the wheels 11 and 16 come into contact with the wall on which they are attached.
is output, and if there is no contact, a third signal 63 is output.
It is intended to stop.

The limit switch SW3 outputs a fourth signal 64 when it is not in contact with the wall behind the welding line to be welded, and stops the fourth signal 64 when it is in contact with the wall.

Further, in FIG. 4, reference numeral 40 denotes a control device comprising a welding permission means, or an AND gate 41, a position detection means, or a stepping circuit 42, and a delay circuit 43.

The AND gate 41 is connected to each normally closed contact of the detection switch SW1 and the limit switch SW3, and to the normally open contact of the limit switch SW2.
When the third and fourth signals 61, 63, and 64 are input together, a welding permission signal 70 is output, and when the output of any one of the first, third, and fourth signals 61, 63, and 64 stops, a welding permission signal is output. This is to stop the output of 70.

The stepping circuit 42 is a detection switch SW1.
When the second signal 62 is inputted, it is notified that the welding cart 10 has reached the corner of the grid structure, and then the second signal 62 is inputted. When input, it is notified that the next corner has been reached, and when the last corner is reached, the delay circuit 43 returns to normal.

When the delay circuit 43 is informed by the stepping circuit 42 that the last corner has been reached, the delay circuit 43 inputs an output signal indicating that the last corner has been reached to the stepping circuit 42 after a predetermined period of time, and causes the stepping circuit 42 to recover. It is something that makes you

44 is a welding power source connected to the output side of the AND gate 41 and the stepping circuit 42, and a welding permission signal 70 from the AND gate 41 is connected to the output side of the AND gate 41 and the stepping circuit 42.
When inputted, preset welding conditions are read based on the position from the stepping circuit 42, and a discharge current corresponding to the conditions is supplied to a welding part (not shown).

Reference numeral 45 denotes a motor drive section provided on the welding cart 10, which drives the front wheels 11 until it is notified from the stepping circuit 42 that it is the last corner.

Note that the wire feeding mechanism and the CO ₂ supply mechanism are also provided in the embodiments shown in FIGS. 1, 2, and 4, but they are not shown because they are not particularly related to the features of this invention. .

Next, as shown in FIG.
The fourth operation is performed when fillet welding of a square structure consisting of parts 2 and 33 is performed starting from the workpiece to be welded 30.
This will be explained with reference to the figures and FIG.

The front wheel 11 is rotated by the drive of the motor 14, and the front wheel 11 and the rear wheel 16 are connected to the vertical surface 3 of the workpiece 30 to be welded.
The member to be welded 30 is welded under predetermined welding conditions while moving the welding cart 10 along the vertical surface 30 while being magnetically attracted to the member 0a. At this time, as shown in FIG. 6a, the limit switch SW2 is in contact with the vertical surface 30a of the welded member 30, so it is closed, and the detection switch SW1 and the limit switch SW2 are closed.
3 is in a non-operating state, the output signal of the AND gate 41 in FIG. 4 is 1, and this output signal causes the welding power source 44 to operate and generate an arc.

Next, the welding cart 10 moves forward, and as shown in FIG.
1, the detection switch SW1 operates,
The normally closed contact is opened and the welding operation is stopped. On the other hand, the normally open contact of detection switch SW1 is closed,
This signal is output to the stepping circuit 42 to operate the stepping circuit 42 one step, and an output signal 43a is input to the welding power source 44. The welding power supply unit 44 switches welding conditions such as welding current and arc voltage to welding conditions for the workpiece 31 determined in advance by the signal 43a.

Further, if the contact points between the members to be welded 30, 31 and the front wheel 11 are 30b, 31b, the notch comes into contact with the contact point 31b, as shown in FIG. 6b, and the contact point 30
When the part that is not the notch comes into contact with b, the contact point 30
Since the magnetic force at point b is greater than the magnetic force at contact point 31b, front wheel 11 spins idly. However, as shown in FIG. 6c, when a part other than the notch contacts the contact point 31b and a notch contacts the contact point 30b, the magnetic force at the contact part 31b becomes larger than the magnetic force at the contact point 30b. Therefore, the welding cart 10 starts to turn in the direction of the arrow 51, and a turning state as shown in FIG. 6d is obtained.

When the welding cart 10 starts turning, the detection switch is activated.
The normally closed contact of SW1 is closed again, but since the limit switch SW2 is open, the welding operation remains in a stopped state.

Next, once the welding cart 10 has finished turning, the limit switch SW3 contacts the vertical surface 30a of the workpiece 30 to open, as shown in FIG. 6e, and closes again when it leaves the workpiece 30. be done.
Here, the welding operation is performed again under welding conditions suitable for the member 31 to be welded.

The above operations are performed between the members to be welded 31 and 32 and between the members to be welded 32 and 33 to advance welding.
At this time, the output signal 43 of the stepping circuit 42
The welding conditions of the welding power supply section 44 are switched in steps b and 43c to weld the members 32 and 33 to be welded.

After welding of the welded member 33 is completed, the welding cart 10
comes into contact with the workpiece 30 at the welding start position and the detection switch SW1 operates, the stepping circuit 42 outputs an output signal 43d to the welding power source 44 and motor drive section 45, and the welding power source 44 and motor drive section 45 Turn off the power to finish welding.
Further, this output signal 43d is input to the stepping circuit 42 via the delay circuit 43, and the stepping circuit 42 is reset.

As described above, when the welding cart 10 comes to a corner and automatically turns, the detection switch SW is activated.
1. Stop the welding operation for a certain period of time by operating limit switches SW2 and SW3. A non-welded part is generated in response to this stop time, and the length of the non-welded part depends on the dimensions of the welding cart 10, but according to the actual machine according to the above embodiment, the length can be kept to about several centimeters. There is.

〔Effect of the invention〕

As explained above, this invention detects the front wall with a detection switch installed on the front of the welding cart that can automatically turn the corner part of the grid structure.
Since the predetermined welding conditions can be switched, welding of different leg lengths can be performed automatically, and it has the effect of automating horizontal fillet welding of ship's square structures with simple and compact equipment. .

[Brief explanation of drawings]

FIG. 1 is an explanatory rear view showing an embodiment of the present invention;
Fig. 2 is an explanatory top sectional view, Fig. 3 is an explanatory sectional view of the front wheel of the above embodiment, Fig. 4 is a block diagram of the control device of the above embodiment, and Fig. 5 is a cross-sectional explanatory diagram of the above embodiment. Explanatory diagram when applied to fillet welding, Fig. 6a,
b, c, d, and e are diagrams illustrating the operation of the above embodiment. 10... Welding trolley, 11... Front wheel, 12... Iron piece, 13... Magnet, 14... Motor, 16... Rear wheel, SW1... Detection switch (first switch),
SW2...Limit switch (second switch),
SW3...Limit switch (third switch),
41...And gate (welding permission means), 42...
...Stepping circuit (position detection means), 44...
Welding power supply section.

Claims (1)

[Claims] 1. Attach the front and rear wheels, which contain magnets and move along the grid on the inner surface of the vertical surface by a magnetic force acting between them and the vertical surface of the grid structure, to a welding cart, and then attach the front wheels to the welding cart. In an automatic welding device with a driving wheel and a rear wheel as a follower wheel, the notch portion is unevenly distributed around the driving wheel to change the distribution of magnetic force on the circumference, and the rear wheel is a follower wheel. , a first switch that outputs a first signal when the welding line is not in contact with the wall in front of the welding line, and stops the first signal and outputs the second signal when the welding line contacts the wall; It is installed between the front wheels and the rear wheels on the side of the welding cart, and when these wheels contact the wall on the side to which they are attracted, a third signal is output, and when they are not in contact, the third signal is output. A second switch is installed on the rear surface of the welding cart, and outputs a fourth signal when the welding line is not in contact with the wall behind the welding line to be welded, and outputs the fourth signal when the welding line is in contact with the wall. When the third switch to be stopped and the first, third, and fourth signals are input together, a welding permission signal is output, and the output of any one of the first, third, and fourth signals is stopped. Then, the welding permission means stops outputting the welding permission signal, and when the second signal is input, it is notified that the welding cart has reached the corner of the square structure, and when the second signal is input, ,
a position detection means that notifies the user that the next corner has been reached, and that is reset when the last corner is reached;
When a welding permission signal is input from the welding permission means, the welding power source section reads preset welding conditions based on the position from the position detection means and supplies a discharge current according to the conditions. An automatic welding device characterized by: