JPH0783943B2 - Resistance welding equipment for metal grids - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resistance welding apparatus for a vertical member (bearing bar) and a horizontal member (crossbar), which is the first part of the manufacturing process of a metal grid, commonly called a steel grating, and particularly to two horizontal members. It is a device that employs a series welding method that simultaneously welds each one.

[0002]

2. Description of the Related Art A metal grid, which is often used as a lid for road grooves, masts, etc., uses a strip steel plate such as flat steel as a vertical member, and a horizontal bar with a square bar twisted on it one after another for resistance. A long (6 to 8 m) grid original plate is made by welding, this is divided into required dimensions, and both end plates are welded and finished. Therefore, the first step in the manufacturing process of the metal grid is to send long vertical members in parallel to the welding machine intermittently, and insert one horizontal bar inserted from the side, or two vertical bars at the same time. This is a resistance welding process in which the upper edge is pressed and pressure-bonded.

[0003]

Two horizontal bars are welded by the series welding method (see welding electrodes E and E'in FIG. 1) rather than welding one horizontal bar on each of the vertical members arranged in parallel. It is more efficient to send them to the welding position and perform simultaneous welding. However, as illustrated in FIG. 4, after all the horizontal bars 2 are welded on the long vertical member 1, the horizontal bars 2 are divided into 350 mm each, and the horizontal bar 2 has three drawing dimensions. The pitch of 100 mm between the two horizontal bars 2 to be simultaneously welded in series welding must be 150 mm at the planned dividing position. Furthermore, the center C of each pitch is the center C between both electrodes E and E for series welding.
The feed distance of the longitudinal member 1 must also be changed to match (see FIG. 1). Since the metal grate is produced in various types in small quantities,
It is necessary to have versatility to make products of various sizes with the same welding machine, but it has been said that it is incompatible to make this an efficient series welding method and to automate it as a whole. The present inventors have taken up the above problems as the most important issues as a manufacturer of resistance welding machines for metal grids for 30 years.

[0004]

A resistance welding device for metal grids according to the present invention is a series welding method in which two horizontal rods are successively placed on long vertical members for metal grids that are arranged in parallel horizontally and at a constant pitch. In a welding device that crimps two horizontal bars at a time, all of them are grouped together, and the vertical member with the lower edge of each member placed on the welding backing material is moved vertically by a required distance, and a vertical member drive device, Two horizontal bars are placed side by side and stick out from the side, just below the center between both electrodes for series welding, a horizontal bar supply device that stops the center of the pitch between both horizontal bars, and scoop up the two horizontal bars, With or without adjusting the pitch between the rods, a horizontal rod positioning device for lowering and placing the two horizontal rods on the vertical member while being pressed down by the electrodes, and a horizontal rod to be welded to the vertical member Enter each pitch length with a consistent number from the welding start end, and then weld The center of the horizontal bar pitch of the odd-numbered,
A series computer is provided with a control computer provided with a vertical member driving distance calculation formula for stopping at the center between both electrodes.

Further, in the above device, the horizontal bar positioning device comprises four elevators with bar receivers for scooping both ends of the two horizontal bars, and two bar receivers on one side for the vertical member. Move symmetrically along. A common reverse screw drive mechanism is provided on both sides.

[0006]

The operation of supplying the horizontal bars one after another onto the long vertical member at an indefinite pitch as designed can be easily automated by the control computer. However, if not only the horizontal bar is placed but also it is properly held until the moment of welding, and the center between a pair of horizontal bars to be series-welded must be aligned right below the center between the series electrodes, the Automation becomes difficult.

When the horizontal bars are supplied at an indefinite pitch, it is common sense to sequentially feed the horizontal bars one by one. However, in the present invention, two horizontal bars for series welding are sent to the welding position at a time. As a result, the center between the two horizontal bars can be accurately aligned right below the center between both electrodes for series welding, and the dimensional accuracy of the product can be improved.

However, since the interval between the two horizontal bars, that is, the pitch, is indefinite, the horizontal bar supply device supplies the two horizontal bars, which have a predetermined pitch in advance, from the side to below the electrodes. Or, it is supplied at a standard pitch, and the horizontal bar positioning device that has received it adjusts the pitch between the horizontal bars to the required pitch. Both horizontal bars, whose center is aligned with the center of both electrodes at the required pitch, are sandwiched between the positioning device and the electrodes and descend onto the vertical member, and are welded as it is, so the dimensional accuracy of the product is high.

As another means for instructing the vertical material feed length to the vertical material driving device, the horizontal bar pitch over the entire length of the long vertical material is input to the control computer with a consistent number, and an odd numbered pitch is entered. After welding both horizontal bars of, by giving the calculation formula of the vertical material driving distance to match the center of the next odd numbered pitch directly under the center between the series electrodes,
Achieved full automation. As a means for adjusting the pitch of a pair of horizontal bars scooped by the horizontal bar positioning device, each bar end is supported by four bar supports and symmetrically moved by a common reverse screw drive mechanism on both sides, so that the horizontal bar is adjusted by pitch adjustment. Can prevent tilting of the rod.

[0010]

1 and 2 show an embodiment of the present invention. 1 is a long vertical member, 2 is a horizontal bar, and E is a series welding electrode, E'is its welding position, C is its center, and B is the welding backing material. The center C between the pair of horizontal bars 2, 2 supplied below the electrodes E, E overlaps the center C between the electrodes. As shown in FIG. 2, in this embodiment, only six vertical members 1 are arranged in parallel, and these are intermittently driven by a vertical member driving device 3 having a clamp 3a and a fluid pressure cylinder 3b.
When the clamp 3a grips or adsorbs the vertical member 1, the fluid pressure cylinder 3b pushes the vertical member 1 a required distance to move the clamp 3a.
When a separates the vertical member 1, it is pulled back. The vertical member 1 has its lower edge placed on the welding backing member B and is guided by a guide device (not shown).
Go straight ahead. In many cases, dozens of vertical members are actually arranged in parallel, but the clamps can be held together without changing the relative positions, and only part of them can be added. Although omitted in the figure, the vertical member driving device 3 is also provided on the opposite side of FIGS. This is because the end portion of the vertical member 1 is pulled and moved.

In order to measure the moving distance of the clamp 3a, that is, the forward moving distance of the vertical member 1 and feed this back to the control computer, in this example, the rack R along the vertical member is attached to the clamp 3a, and the movement taken out by the pinion P or the like. The distance is sent via the encoder E. The horizontal bar supply device 4 stores a large number of horizontal bars 2 and a well-known tilted supply mechanism 4a for sequentially dropping the horizontal bars 1 from the lower end, and a standard between the horizontal bars after receiving the dropped horizontal bars 2 in the front groove. The next horizontal bar 2 is received in the rear groove by advancing by the pitch P, and then further advanced, and the center of the pitch between the two horizontal bars 2 and 2 reaches directly below the center C between the series electrodes E, and stops. A horizontal bar receiving frame 4b,
The horizontal reciprocating fluid pressure cylinder 4c.

In this embodiment, when the horizontal bar receiving frame 4b on which two horizontal bars 2 are placed at the standard pitch P comes out and stops,
The center C of the pitch P between both horizontal bars is located just below the center C of both electrodes. The center C of both rods and both electrodes is a vertical plane, but the center line C is shown in elevation and plan views.
Can be seen. In FIG. 1, only the state where the horizontal bar receiving frame 4b is in the standby position for receiving the horizontal bar 2 in the front groove is shown by a solid line. After this, the horizontal bar receiving frame 4b advances to the right in the figure by the standard pitch P, receives the horizontal bar 2 also in the rear groove, and then comes out at a distance, and then stops at the position indicated by the chain line in FIG.

The horizontal bar at the position of the chain line is 2 '. Scoop up the two horizontal bars 2'and float to the position of the horizontal bar 2 ",
It is the horizontal bar positioning device 5 that enables the horizontal bar receiving frame 4b to return to the standby position. The operation of the horizontal bar 2'will be described later. In the horizontal bar positioning device 5 of this embodiment, a lifting mechanism 5b with four bar receivers 5a for scooping the two ends of the horizontal bar 2 into each one, and two bar receivers 5a on one side for each lifting mechanism 5b. , A common reverse screw drive mechanism 5c on both sides for symmetrically moving along the longitudinal member 1. The drive mechanism 5c rotates the reverse screw rod by the motor M to move the lifting mechanism 5c.
It is a well-known structure that separates or approaches b symmetrically.
In order to send the symmetrical movement amount to the control computer, the lifting mechanism 5b is provided with a feedback device similar to the vertical member driving device 3.

The rod receiver 5a in FIG. 1 is in the standby position. The rod receiving member 5a has a V groove at the upper end, and two horizontal rods 2 on the horizontal rod receiving frame 4b are two electrodes 2E below both electrodes E for series welding.
When it comes to position 2, it is picked up and supported at the position of 2 ". Then, both electrodes E, E are pressed down and placed on the horizontal bar 2". In this way, the horizontal bar 2 ″ is sandwiched between the electrode E and the rod receiving member 5a, and the electrode pressing force exceeds the pushing force of the elevating mechanism 5b, so that the rod rod 5a is lowered while being sandwiched. When the rod 2 is placed on the upper edge of the vertical member 1, the rod receiver 5a stops while sandwiching the rod 2. At the welding start signal, the rod receiver 5a moves down to the standby position shown by the solid line in FIG. E is pressurized and energized to crimp the horizontal bar 2 to the vertical member 1.

The horizontal bar feeder 4 of the above embodiment always supplies two horizontal bars at the standard pitch P below the electrodes, and leaves the necessary pitch adjustment to the horizontal bar positioning device 5 below. Instead, the horizontal bar supply device 4 itself may sequentially supply two horizontal bars at a required indefinite pitch. In that case, the horizontal bar supply device 4 receives two horizontal bars at a standard pitch P on the horizontal bar receiving frame 4b, symmetrically moves them to a required pitch, and then advances them to below the electrodes or drives the cylinder 4c. A well-known technique for control engineers, such as replacing the drive mechanism that can be controlled by a computer with one horizontal bar at a required pitch one by one on the horizontal bar receiving frame The detailed description is omitted because it can be designed more easily.

FIG. 3 is a control-related block diagram of the embodiment shown in FIGS. Reference numeral 10 is a computing unit of a computer, 11 is a display unit, 12 is a printer, and 13 is a driving machine. Vertical material,
Depending on the size and number of the horizontal bars, welding conditions such as welding current, pressing force, pressurizing time are calculated from the calculation unit 10 to the control unit 1 of the welding machine 15.
It is a well-known technique to give instructions to 4. In addition to this, the arithmetic unit 10 commands the vertical member driving device 3 and the horizontal bar positioning device 5 to receive the feedback of the actual operating distance between them. That is, the arithmetic unit 10 obtains the difference between the pitch P _{X of the} two horizontal bars to be welded next and the standard pitch P from the horizontal bar pitch with the consistent number given earlier, and both horizontal bars 2 are obtained by the difference. , 2 is commanded to the reverse-screw drive mechanism 5c for the rotation angle of the motor M required to move symmetrically.

When the horizontal bar positioning device 5 scoops up the supplied horizontal bars 2 and 2 to the positions of 2 "and 2" in FIG. 1, the motor M is rotated by the required rotation angle according to the above command, Perform pitch correction. The horizontal bars 2 and 2 are lowered and placed on the vertical member 1 at the corrected pitch. Figure 4 shows a long vertical member 1.
Then, serially weld two horizontal bars 2 from the right end,
Then, a simple example in which the vertical member 1 is divided into 350 mm pieces to obtain a homogenous metal grid will be shown. Horizontal bar pitch P ₁ , P ₂ , P
₃ Enter the serial number from the welding start (right) end to the computer. The pitch of the pair of horizontal bars 2, 2 to be series-welded is odd-numbered P ₁ , P ₃ , P _5, ...

The pitch P ₁ of the two horizontal bars to be welded _first is 1
At 00 mm (this is the standard pitch P in FIG. 1),
The two pitches P ₃ to be welded next are as long as 150 mm because they include the vertical member cutting position. The next pitch P ₅ and the next P
₇ is a standard pitch of 100 mm. These are compared with the standard pitch each time, and if there is a difference, the pitch is corrected. After welding at the pitch P ₁ of FIG. 4, the distance by which the vertical member 1 is advanced is 225 mm from the center C of the horizontal bar pitch P _{1 to} the center C of the pitch P ₃ .

The calculation formula of the vertical member driving distance is (half of P ₁ ) + (P ₂ ) + (half of P ₃ ), and this is given to the computer. Is calculated as 225 mm, and this is instructed to the vertical member driving device 3. The vertical member driving distance of the second time is also 225 mm, but the third
The turn changes to 250 mm. In the case of FIG. 5, the vertical member driving device up to the second and third times is 225 mm, and the fourth time is 250 m.
m, the fifth time is 275 mm. If the width of the lower surface of the electrode E is made wider, the distance between the electrodes does not have to be changed even if the horizontal bar pitch changes, but the interval may be variable if necessary.

The embodiment shown in the drawings has been described above.
The present invention should be changed and applied according to the implementation conditions within the scope of the gist of the present invention. The vertical member clamping mechanism and the driving distance measuring mechanism of the vertical member driving device 3 and the horizontal rod mounting device of the horizontal rod feeding device 4 should be used. The placement, sticking out mechanism, sticking out amount measuring mechanism, mechanism for stopping at the normal position, raising and lowering of the horizontal bar positioning device 5, pitch adjusting mechanism and the like are left to the well-known techniques of machine designers.

Further, as described above, the horizontal bar pitch adjusting mechanism is added to the horizontal bar supply device 4 to eliminate the reverse screw drive mechanism 5c of the horizontal bar positioning device 5, and the front and rear bar receivers 5a are made of an integral horizontal member. You may change to the thing which many receiving grooves were located in a line at the upper edge. Alternatively, instead of receiving the horizontal bars 2 at both ends, the horizontal bars 2 may be received at the central portions and moved up and down.

[0022]

According to the present invention, a horizontal bar is sequentially welded to the entire length of a long vertical member to form a grid original plate, and the grid original plate is divided into a plurality of metal grid materials. Both series welding and full automation have been achieved. It inputs to the control computer the pitch of all horizontal bars that should be attached to the entire length of the long vertical member with a consistent number from the welding start end, and the center of the odd numbered horizontal bar pitch is the center between the electrodes for series welding. Since we have given the formula for calculating the driving distance of the vertical member to stop at the same time, it is possible to easily make any grid original plate with a horizontal bar of indefinite pitch.

Even if the control system is improved in this way, it cannot be put into practical use unless the press-fit welding between the upper edge of the vertical member of the lattice and the twisted horizontal bar is always performed accurately. According to the present invention, two lateral rods which are easily rolled are projected laterally by the lateral rod feeding device so that the center of the pitch between the rods always stops directly below the center between both electrodes. Then, the horizontal bar positioning device scoops up the two projected horizontal bars, and if necessary, after adjusting the pitch, the two horizontal bars are pinched between the bar receiver of the positioning device and the electrode to be pressed down. It can be mounted on the vertical member without being able to make slight movements, and the welding is completed by energizing it. Therefore, the horizontal bar is not likely to roll during positioning, and does not move even when the electrode is strongly pressed because it is pre-pressurized.

According to the present invention, the metal grid designer can be freed from the constraint of making the horizontal bar pitch constant for the convenience of manufacturing as in the past, and the manufacturer can easily and automatically use the grid original plate of any irregular pitch. Moreover, it became possible to make it accurately.

[Brief description of drawings]

FIG. 1 is an elevation view of an embodiment of the present invention.

FIG. 2 is a plan view of the same.

FIG. 3 is a block diagram showing a control relationship of the same.

FIG. 4 is an elevation view of an embodiment of a horizontal bar arrangement.

FIG. 5 is an elevation view of the other embodiment.

[Explanation of symbols]

 3 Vertical member drive device 4 Horizontal rod supply device 5 Horizontal rod positioning device E Welding electrode

Claims (2)

[Claims] 1. A welding apparatus in which two horizontal rods are successively placed on a long vertical member for a metal grid which are horizontally arranged in parallel at a fixed pitch, and two horizontal rods are crimped by a series welding method. The vertical member with the lower edge of each member placed on the welding backing material is moved horizontally by the required distance, and two horizontal bars are placed side by side to project from the side. Directly below the center between both electrodes for welding, a horizontal bar supply device that stops the center of the pitch between the horizontal bars, and scoop up the two horizontal bars to adjust the pitch between the horizontal bars,
Alternatively, while being pressed down by the electrodes, a horizontal bar positioning device for lowering and mounting the two horizontal bars on the vertical member, and a pitch length of the entire horizontal bar to be welded to the vertical member are set at the welding start end. From a horizontal bar pitch of odd number to be welded next, inputting with a consistent number from A resistance welding device for metal grids. 2. The device according to claim 1, wherein the horizontal bar positioning device has four bar receiving and elevating mechanisms for scooping both ends of the two horizontal bars into each piece, and two bar receiving pieces on each side. A resistance welding device for a metal grid, comprising: a common reverse screw drive mechanism on both sides for symmetrically moving along the vertical member.