JPH0216869Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cladding tube manufacturing apparatus for covering the outer circumferential surface of a metal inner tube with a band-shaped metal thin plate.

Generally, the outer peripheral surface of a steel pipe made of a relatively low-quality material is coated with a strip-shaped thin metal plate made of a relatively high-quality material, such as a thin plate of stainless steel, and these are seam-welded, for example, for construction, furniture, or vehicles. Apparatuses for manufacturing cladding tubes used for such purposes are well known.
For example, a manufacturing apparatus shown in FIG. 1 has been proposed in the past. That is, the metal inner tube 1 and the strip-shaped thin metal plate 2 wound around the inner tube are supported by a receiving roller 5' made of an electrical conductor, and the overlapping ends of the metal thin plates are placed above the receiving roller 5'. An electrode trochanter 4 is arranged at a position touching the edge, and the electrode trochanter 4
The cladding tube 3 was manufactured by applying current between the receiving roller 5' and the receiving roller 5', and rotating the receiving roller 5' while pressing the electrode trochanter 4 toward the receiving roller 5'.
By the way, in the conventional apparatus, the cladding tube supported by the receiving roller is pressed against the receiving roller side by the electrode trochanter, and the receiving roller is rotated to move the cladding tube. That is, the electrode trochanter 4
The cladding tube is transported appropriately with the maximum value being the force acting on the contact portion between the cladding tube 3 and the receiving roller 5' due to the pressurization and the force corresponding to the coefficient of friction. Incidentally, the dimensions of the metal inner tube and the metal thin plate are appropriately selected depending on the use of the cladding tube, and the shape of the electrode trochanter is also appropriately selected. In this case, in particular, the value of the pressing force of the electrode trochanter is changed appropriately,
The maximum transfer force of the cladding tube changes corresponding to that value. However, in view of the performance of the device, especially considering the case where the cladding tube is long, it is preferable that the maximum value of the transfer force of the cladding tube can be maintained constant. On the other hand, the receiving roller is made of an electric conductor and is heated because it is energized through the cladding tube. Combined with the pressure applied by the electrode trochanter, the part of the receiving roller that comes into contact with the cladding tube is heated. Severe wear. If the receiving rollers are worn out in this way, it is difficult to maintain the cladding tube transfer speed to be approximately the same as the initial value, and this may result in uneven welding, leading to the production of impractical cladding tubes. It was hot.

In addition, although a large current is normally applied to the electrode trochanter 4, in order to prevent discharge or seizure from occurring due to the energization, the electrode trochanter 4 is slidably connected to the rotating shaft 401 of the electrode trochanter 4. Power is supplied by a so-called power supply brush 11 that is brought into contact with the power supply brush 11. By the way, since a large current is applied to the rotating shaft and the power supply brush, the rotating shaft and the power supply brush are maintained in contact with each other with a considerably large force. Therefore, the frictional force caused by the contact between the rotating shaft and the power supply brush acts on the cladding tube as a braking force as if to prevent rotation of the electrode trochanter. That is, in the apparatus shown in FIG. 1, when seam welding is performed while the cladding tube is being transferred by the receiving roller,
The electrode trochanter also tries to rotate due to the transfer of the cladding tube, but the frictional force caused by the contact between the rotating shaft and the power supply brush acts as a braking force and prevents the electrode trochanter from rotating. As a result, the part of the cladding tube to be welded is pulled in the direction opposite to the direction in which the cladding tube is transported through the electrode trochanter, resulting in a so-called wavy state in the already welded part, which not only looks bad as a product but also makes it difficult to use. When a person grasps this product, there is a high possibility that the corrugated portion may injure the fingers or palm of the hand, so this product cannot be put to practical use.

An object of the present invention is to provide a cladding tube manufacturing apparatus that eliminates the above-mentioned conventional drawbacks.

Hereinafter, the present invention will be described in detail with reference to illustrated embodiments.

In FIG. 2, reference numeral 1 denotes a metal inner tube, and 2 denotes a strip-shaped thin metal plate wrapped around the outer peripheral surface of the metal inner tube 1, with both vertical edges 201 and 202 of the metal thin plate 2 being overlapped. The metal inner tube 1 and the strip metal thin plate 2 constitute a cladding tube 3. 4 is located above the overlapping edges of the thin metal plates 2, and during welding work, the overlapping edges 201, 20 of the thin metal plates 2
A first rotating electrode 5 pressurizes the cladding tube 3, and a second rotating electrode 5 that contacts the cladding tube 3 from the outside.
biased toward the side. A power source 6 is connected to the first and second rotating electrodes 4 and 5 for supplying current between the two rotating electrodes. 7 and 8 are pressure rollers that clamp the cladding tube 3; for example, the pressure roller 8 is connected to a rotary drive machine 9. In this case, for example, the pressure roller 7 may be made of a wear-resistant material to position the cladding tube 3, while the pressure roller 8 may be made of a material with a high friction coefficient, such as rubber, synthetic rubber, or synthetic resin. If cladding tube 3
transfer force is increased. Further, the first rotating electrode 4 is connected to an auxiliary rotating drive 10.

In the above, while the cladding tube 3 is held and positioned by the press rollers 7 and 8, electricity is applied between the first and second rotating electrodes 4 and 5, and the end edges 201 and 202 of the strip metal thin plate 2 and the metal inner tube are 1 is welded. Along with the above energization, the rotary drive machine 9 is driven,
This causes the cladding tube 3 to be transported in the axial direction. By the way, power is supplied to the first rotating electrode 4 through the rotating shaft 401.
and a so-called power supply brush 11 that slides and abuts against the rotating shaft 401. Therefore, a frictional force is generated due to the contact between the rotating shaft 401 and the power supply brush 11, and this frictional force acts as a braking force against the rotation of the first rotating electrode 4.
However, as described above, since the auxiliary rotation drive machine 10 is connected to the first rotation electrode 4, the rotation shaft 4
The frictional force caused by the contact between the power supply brush 11 and the power supply brush 11, that is, the braking force applied to the first rotating electrode 4, is canceled out by the driving of the auxiliary rotational drive machine 10. For this reason, the first rotating electrode 4 and the cladding tube 3 are in a state of rolling contact, and therefore, when the rotary drive machine 9 is driven and the cladding tube 3 is transferred, the first rotating electrode 4 and the cladding tube 3 are moved. The first rotating electrode 4 also rotates to perform welding continuously.

FIGS. 3 and 4 are views showing other embodiments of the present invention, in which the rotating electrode and the pressing roller are spaced apart from each other in the axial direction of the cladding tube 3. FIG.
For example, the second rotating electrode 5 is disposed at a position to the left of the position facing the first rotating electrode 4. The pressing roller is, for example, on the inlet side of the cladding tube 3,
That is, it is placed on the unwelded side, and in the case shown, the cladding tube 3
Pressing rollers 7, 71, and 8 are disposed at positions that approximately divide the outer circumference into three equal parts. In this case, the pressing roller 71 is connected to the overlapping edge 201 of the thin metal plate 2,
The outer periphery of the portion corresponding to 202 is notched appropriately.
The operations of the embodiment shown in FIGS. 3 and 4 and that shown in FIG. 2 are almost the same, so a description thereof will be omitted.

As described above, with the configuration shown in FIG. 2, the rotating axes of the rotating electrode and the pressing roller can be arranged on the same plane in the radial direction of the cladding tube 3, so that they can be connected to the rotary drive machine. Even with a single pressure roller that comes into contact with the cladding tube, the cladding tube can be transferred over the entire length, and the apparatus can be made more compact. Despite this, the pressure roller and the rotating electrode can be separated from each other in the axial direction of the cladding tube. In this case, pressure rollers are disposed on each side of the cladding tube extending over the rotating electrode in the axial direction, that is, on the inlet side and the unloading side of the cladding tube with respect to the rotating electrode, and at least one of each press roller is provided.
It is preferable to connect rotary drive machines individually. That is, a separate rotary drive machine can be connected to each of the rotary drive press rollers and electrically cooperate with each other as appropriate to transport the cladding tube. In this case, the rotary drive machine may be driven at the same time, or the press roller for one rotation drive may be driven to rotate before the contact between the pressure roller for one rotation drive and the cladding tube is released. Can be done. It is also possible to connect a single rotary drive machine and each rotary drive pressing roller via an appropriate rotation transmission means. Furthermore, as shown in FIGS. 3 and 4, if three or more pressing rollers are arranged on the inlet side of the cladding tube with respect to the rotating electrode, the restraint of the thin strip 2 with respect to the inner tube 1 and the positioning of the cladding tube 3 can be improved. It can be carried out reliably. In this case, among the pressure rollers 71,
If the outer periphery of the overlapped edges 201 and 202 of the thin metal plate 2 is notched, the overlapping state of the edges can be maintained at the desired state, but the pressing roller 7
If the cutout portion of No. 1 is formed to be somewhat smaller than the overlapping state, the pressing roller 71 will make the contact between the overlapping edges uniform, that is, the overlap between the overlapping edges will improve. It becomes easier to obtain uniform welding results. Furthermore, if the pressure roller 7 is arranged at a position corresponding to the welded part after welding, the pressure roller 7
As the welded part is forcibly pressed and swaged, the welded part becomes flat and
It is possible to manufacture a cladding tube with extremely few irregularities as a whole. Of course, it is also possible to increase the transport force of the cladding by connecting two or more pressure rolls to a rotary drive. Furthermore, two second rotating electrodes may be provided on the outer circumference of the cladding tube.

As described above, according to the present invention, the pressing roller and drive mechanism for restraining and positioning the cladding tube and transporting the cladding tube, and the rotating electrode and energization mechanism for welding the cladding tube are each configured separately. Therefore, the welding current does not flow through each part of the pressure roller, and therefore the pressure roller can be used for a long time without being heated. The transfer speed of the cladding tubes can be appropriately adjusted independently of each other without any influence on each other. In addition, the second rotating electrode is heated when energized, but unlike the conventional situation in which the second rotating electrode and the cladding are in contact with each other with a large pressure force, the second rotating electrode is separated from the cladding. Since the second rotating electrode is brought into contact with such a force that it does not wear out, wear of the second rotating electrode is extremely small, and the second rotating electrode can be used for a long time. Furthermore, during welding, by driving the auxiliary rotary drive machine connected to the first rotating electrode, the frictional force caused by the contact between the rotating shaft of the first rotating electrode and the power supply brush is canceled out, and the first Since the rotating electrode and the cladding tube are in a state of rolling contact, it is possible to obtain a smooth cladding tube without the corrugations that conventionally occur. Therefore, it is possible to mass-produce a product that has a good appearance and has great practical value without causing injury to the user.

The combination of the above effects makes it possible to manufacture a cladding tube with good welding results, and allows the manufacturing equipment to be used for a long life, which is industrially beneficial.

[Brief explanation of the drawing]

Fig. 1 is a schematic front view showing a conventional example, Fig. 2 is a schematic front view showing an embodiment of the present invention, Fig. 3 is a schematic front view showing another embodiment of the present invention, and Fig. 4 is a schematic front view showing a third embodiment of the present invention. FIG. 3 is a schematic front view showing the arrangement of the pressure rollers shown in the figure. 1...Metal inner tube, 2...Strip metal thin plate, 20
DESCRIPTION OF SYMBOLS 1,202... Edge of strip-shaped thin metal plate, 3... Covering tube, 4... First rotating electrode, 5... Second rotating electrode, 7, 71, 8... Press roll, 9... Rotating Drive machine, 10...Auxiliary rotary drive machine.

Claims (1)

[Claims for Utility Model Registration] 1. In a cladding tube manufacturing apparatus in which the outer surface of a metal inner tube is covered with a strip-shaped thin metal plate and the overlapping edges of the strip-shaped thin metal plate are seam welded, the overlapping edge of the thin metal plate is A first rotating electrode pressurized at the edge and at least one second rotating electrode abutting the cladding tube from the outside.
a rotary electrode, at least two press rollers that sandwich the cladding tube, and a rotary drive machine connected to at least one of the press rollers, and the first rotary electrode is connected to an auxiliary rotary drive machine. A cladding tube manufacturing apparatus comprising: a power source connected to the first rotary electrode and a power source for supplying current between the first and second rotating electrodes; 2. The manufacturing apparatus according to claim 1, wherein a plane including the rotational axes of the first and second rotating electrodes substantially coincides with a plane including the rotational axes of the pressing roller. 3. According to claim 1 of the utility model registration claim, a plane including the rotational axes of the first and second rotating electrodes and a plane including the rotational axes of the pressing roller are spaced apart in the axial direction of the cladding tube. The manufacturing equipment described. 4. The manufacturing apparatus according to claim 1 or 3, wherein at least two pressing rollers are respectively disposed in the axial direction of the cladding tube that straddles the rotating electrode. 5. The manufacturing apparatus according to claim 1, 3, or 4, wherein three pressing rollers are disposed on the inlet side of the cladding tube relative to the rotating electrode. 6. The manufacturing apparatus according to claim 5, which is a registered utility model, wherein the outer peripheral portion of the three pressing rollers corresponds to the overlapping edge of the thin plate. 7. Utility model registration according to any one of claims 4 to 6, in which a rotary drive device is connected to at least one of the press rollers disposed across the rotating electrodes. manufacturing equipment.