JPH0233998Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to an intermittent presswork welding device suitable for manufacturing pipes and the like.

[Prior Art] As is well known, in pipe-making lines for manufacturing long pipes, the mainstream is to continuously weld workpieces formed by roll forming using a welding device.

On the other hand, by welding workpieces formed by press forming rather than roll forming, products have been created that aim to make the forming equipment smaller and cheaper, and further improve the precision of the product. There is.

FIGS. 3a and 3b are schematic diagrams showing the configuration of this type of press-type tube manufacturing line. In the same figure a, 1
is a press molding device. This press molding device 1
In this case, the press forming mechanism and the workpiece ejection mechanism are integrated, and the vertical movement of the press mechanism is converted into horizontal movement by the workpiece ejection mechanism, and this force is used to intermittently eject the workpiece 2 in small pitches P at a time. It's summery.

A welding device 3 is arranged downstream of the press forming device 1. The welding device 3 welds the workpiece 2 during the feeding period of the workpiece 2, and includes a tachometer generator 4 that detects the feeding speed, a command circuit 5 that forms a welding current command according to the feeding speed, and a command circuit 5 that generates a welding current command according to the feeding speed. The welding power source 6 outputs a welding current according to the welding current, and the torch 7 performs welding using the welding current.

Then, during the period of intermittent feeding, a welding current command is generated according to the feed speed of the workpiece 2, and welding is performed intermittently at each feeding pitch P.

On the other hand, Figure b shows an improved version of this. That is, a drive mechanism 8 that reciprocates the torch 7 in the moving direction of the workpiece 2 or the opposite direction is provided, and welding is performed by moving the torch 7 at a constant speed by the feed pitch P during the period when intermittent feeding is stopped. was. This device has the advantage that the moving speed of the torch 7 can be kept constant.

[Problems to be solved by the invention] By the way, in the conventional device described above, as shown in FIG. It was hot. This is because the feed pitch P is short and uneven penetration inevitably occurs during this time. In order to avoid such inconveniences, very complicated welding current control had to be performed.

This invention was made against this background, and the purpose is to provide an intermittent presswork welding device that can perform welding with an optimal constant welding current while feeding the torch at a constant speed. do.

[Means for Solving the Problems] In order to solve the above problems, this invention includes an intermittent forming press device that intermittently discharges the forming workpiece, and a device located downstream of the intermittent forming press device that discharges the forming workpiece. In an intermittent forming press work welding device that includes a welding device that performs welding, a clamp means that grips and releases the formed work, a conveying means to which the clamp means is fixed, and a welding device that is supported by the conveying means and moves along the formed work. and a torch feeding device that reciprocates the torch of the welding device, the torch is moved in one direction while the clamping means grips the molded workpiece, and the torch is moved in one direction, and after welding, the molded workpiece is welded. , and the conveying means and the torch are returned to their original positions.

[Operation] According to the above configuration, while the clamp grips the work, the work and the conveying means move together. Therefore, the workpiece is in a stopped state with respect to the conveyance means, and during this time, the torch can be moved at a constant speed and welded with a constant optimum welding current. In this case, since the work gripping period of the clamp can be considerably longer than the pitch feeding period, a homogeneous bead without fine wavy irregularities can be formed.

[Example] Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 1 is a diagram showing the configuration of an embodiment of this invention. In the figure, 11 is a rectangular parallelepiped-shaped truck. As the workpiece 2 moves, the trolley 11
It runs on rails 12 laid in the direction of movement, and is driven by a trolley feed motor 13.

A clamp 15 for gripping and releasing the workpiece 2 is attached to the upper surface of the cart 11. The clamp 15 has a horizontal push clamp 15a that clamps the workpiece 2 from both sides, and a welding clamp 15b that suppresses the joint portion of the workpiece 2 from diagonally above. Here, the welding clamp 15b is fixedly installed, but the lateral push clamp 15a is driven to open and close in the lateral direction by an air cylinder (not shown). That is, it is driven to close to grip the workpiece 2, and driven to open to release the workpiece 2.

Next, a support section 17 is erected on the upper rear surface of the truck 11, and a torch feeding device 18 is attached thereto. The torch feed device 18 includes a feed screw 19 provided horizontally, a torch feed motor 20 that rotates the feed screw 19 in both forward and reverse directions, and a torch feed motor 20 that is screwed onto the feed screw 19 and rotates as the feed screw 19 rotates. It consists of a torch traveling unit 21 that travels in the moving direction of the workpiece 2 or in the opposite direction, and the torch 7 is fixed to this torch traveling unit 21. When the torch 7 is moved by the torch feed motor 20, the tip of the torch 7 runs along the seam of the workpiece 2 and directly above it. Incidentally, the torch 7 is attached with a torch adjust unit 7a, and the position of the torch 7 can be finely adjusted.

In such a configuration, the steel strip 2a is formed into a tubular workpiece 2 by the press forming device 1 and discharged in feeding pitches P by pitch.

Now, if the side push clamp 15a is closed when the rear end of the cart 11 is at point C in FIG.
It is sent downstream (toward the right in the figure) one by one. When this feeding is started, the torch 7 welds the workpiece 2 with a constant welding current while moving from point A to point B (in other words, in the upstream direction) at a predetermined constant feed rate. . In this case, the welding length is L,
Letting D be the feed amount of the workpiece 2 and the truck 11 during this welding period, it is set so that L>D (1).

After the above-mentioned welding is completed, the trolley 11 and the torch 7 are returned to their initial positions and wait for the start of the next welding. That is, the horizontal push clamp 15a is opened to release the workpiece 2, the cart 11 is returned by a distance D and brought to the original position C, and the torch 7 is returned from point B to point A, and in this state, the workpiece 2 is released. 2 next welding starting point,
In other words, wait until the previous welding end point is directly below the torch 7. That is, the workpiece 2 is transported a distance L measured from the previous welding start point, and the next welding start point is placed directly below the torch 7.

Next time, when the welding start point is directly below the torch 7, the workpiece 2 is again gripped by the horizontal push clamp 15a, and welding is performed at a constant speed and with a constant current in the same manner as above. This operation is repeated, and work 2
The seams are welded in length L increments.

FIG. 2 shows a specific example of the above operation, in which the welding length L=700 mm, the carriage feed length D=350 mm, and the feed pitch P=25 mm. Here, if one cycle of the press forming apparatus 1 is T, the workpiece 2 is sent out by a pitch P during a time T, a distance D during a time 14T (see b in the same figure), and a distance D during a time 28T. It is sent out a distance L (see c in the same figure).

The torch 7, which started welding at time t=0 (see a in the figure), finishes welding the length L before reaching time t=14T while moving in the upstream direction. After the welding is completed, the torch 7 and the truck 11 each return to their initial positions at time t=0, and the next welding start point of the workpiece 2 is located directly below the torch 7. Then, at time t=28T, when the next welding start point comes directly below the torch 7, the clamp 15 grips the workpiece 2, and the next welding is started in the same manner as above.

Note that control during this time is performed by a control device (not shown), and the amount of feed of the workpiece 2, etc. is detected based on time. This time-based control is possible because the forming press device 1 feeds the workpiece 2 by a certain feed pitch P in a certain time T.

In the above embodiment, the workpiece 2 is sent out on the forming press device 1 side, but it may be taken up on the welding device side.

Further, the means for supporting and transporting the torch 7, clamp 15, torch feeding device 18, etc. is not limited to the trolley. For example, the above components may be arranged on a slider that is screwed into a feed screw, and the feed screw may be driven by a motor to convey these components.

[Effects of the invention] As explained above, this invention can transport the workpiece that is intermittently sent out from the forming press device and the conveying means that conveys the torch and the torch feeding device.
The workpiece is moved together for a certain period of time, and during this period the torch is moved by the torch feeder during welding. After welding, the workpiece is released from the conveyance means, the torch and the conveyance means are returned to their original positions, and the torch and conveyance means are returned to their original positions. Since welding is performed by repeating the same welding motion, the torch can be fed at an optimal constant speed and the workpiece can be continuously welded over a certain length, regardless of intermittent feed. This allows welding at a constant speed and constant current to achieve the best penetration.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the configuration of an embodiment of this invention, in which a is a plan view, b is a front view, c is a side view, and d is an enlarged view of the clamp 15. Fig. 2 is a diagram for explaining a specific example of the operation of the same embodiment, Fig. 3 is a schematic diagram showing an overview of a conventional intermittent presswork welding device, and Fig. 4 shows the state of a bead by conventional welding. It is a diagram. 2... Molding workpiece, 11... Cart (transportation means),
15... Clamp, 18... Torch feeding device.

Claims (1)

[Scope of utility model registration request] In an intermittent forming press work welding device comprising an intermittent forming press device that intermittently discharges the forming workpiece, and a welding device located downstream of the intermittent forming press device and welding the forming work, the forming work is gripped, The clamping means is provided with a clamping means for releasing the clamping means, a conveying means to which the clamping means is fixed, and a torch feeding device supported by the conveying means and reciprocating the torch of the welding device along the forming workpiece, Welding is performed by moving the torch in one direction while gripping the molded work, and after welding, the molded work is released and the conveying means and the torch are returned to their original positions. Forming press work welding equipment.