JPS6113187Y2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to a seam guide provided immediately before the welding point of an electric resistance welded pipe manufacturing device.Specifically, the edge part of the material hoop formed by a group of forming rolls is heated by edge heating. The present invention provides a seam guide that maintains the most ideal form and guides the device, the squeeze roll (here pressure welded), and the subsequent device that is continuous.

As shown in Fig. 1, a general electric resistance welded pipe manufacturing apparatus is constructed such that a coil-wound hoop material A with a flat cross-section is attached to an uncoiler B, which passes through a guide roll C and enters a forming roll group D. It is gradually formed into a cylindrical shape, and then both ends of the material hoop A are heated to near the melting point by an edge heating device E, and then the heated edges of the material are heated by a squeeze roll F. After being pressed and welded and cooled in the next cooling device G, the bead portion generated by the previous welding process is removed by a bead cutting machine H, and then the sizing roll group I is used to cut the bead to a uniform predetermined size. Finally, the length of the tube is cut to a predetermined size using a running cutting machine J to produce a product.

As shown in FIG. 2, a seam guide 4 is provided in the edge heating device E of the above-mentioned electric resistance welded tube manufacturing apparatus. After that, it passes through a heating coil 3 to be heated to the temperature required for welding, and then when it is welded by a squeeze roll 2, it is shaped into a cylindrical shape before the heating coil 3 and squeeze roll 2. Molded material hoop material 1
It is provided to maintain the opening angle of the pipe, the balance and position of both edges, etc., and is used in roll-shaped pipes used in medium- and large-diameter pipe manufacturing equipment.
There is a plate-shaped seam guide used to reduce space in small diameter pipe manufacturing equipment, and the present invention relates to the latter.

Fig. 2 shows a conventionally used plate-shaped seam guide, which, as shown in the figure, consists of upper and lower rolls 5a and 5b located at the final stage of the forming roll group (Fig. 1). If the material hoop material 1 leaving the fin pass roll 5 maintains the shape at the position of the fin pass roll 5, the seam guide plate 4 has the opening angle 10 of the material hoop material 1 as described above, and the width of both edges. Although the degree of balance and the welding point 9 can be kept constant, in reality, the elasticity of the hoop material 1 causes the fin pass roll 5 to
As shown in FIG. 5, and the edge portion 1a is large.
is heated and thermally expanded, so that both the edge portion 1a and the bottom portion 1b, which are the upper end sides of the material hoop material 1 that has exited the fine pass roll 5, rise upward as shown in FIG. 4, as shown by solid lines in FIG. The result is an abnormal cross-sectional shape as shown. For this reason, the opening angle 10 of the hoop material 1, the balance between both edges 1a, and the welding point 9, which were tried to be kept constant between the squeeze roll 2 and the seam guide 4, cannot be kept constant, and the long A fatal drawback is that it is no longer possible to manufacture pipes of stable quality, such as the strength of the electric resistance welded part being constant no matter where along the length of the product pipe is taken. have.

The present invention was made in view of the above-mentioned drawbacks, and the purpose is to provide a seam guide that can eliminate the influence of spring back of the material hoop material 1 and obtain a product pipe of stable quality. There is.

An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 5, the seam guide plate 7 is a cylindrical material hoop 1 formed by extending the end of the material hoop 1 of the conventional seam guide plate 4 shown in FIGS. 2 to 4. A contact portion 8 is formed to contact the bottom. Further, the corresponding contact portion 8 is formed with a sliding surface portion 8a having a curved surface equal to the inner radius of the bottom portion of the hoop material 1, and as the case may be, the contact area with the bottom portion of the hoop material 1 may be increased. In order to reduce the contact pressure per unit area and improve wear resistance, the width L of the contact portion 8 is made larger than the thickness l of the seam guide plate 7. Also, as shown by the arrow in Figure b, a sliding surface portion 8a is provided on the bottom end face of the contact portion 8 on the entry side of the material hoop material 1, so that the material hoop material 1 can enter and slide smoothly. . Then, as shown in FIG. 6, the abutting portion 8 of the seam guide plate 7 is attached so as to abut and slide on the bottom of the inner diameter of the hoop material 1. As is clear from the above description, for the seam guide plate 7, since both edges of the material hoop material 1 slide in contact with the bottom of the inner diameter, it is necessary to select a material with high wear resistance and a small wear coefficient. At the same time, as shown in Fig. 6, since it is installed near the induction heating coil 3, it is heated by induction due to the eddy current generated under the influence of high frequency current, so it is desirable that it is an insulating material, and it satisfies these conditions. It is recommended to use ceramic material as the material.

When using the seam guide plate 7 according to the present invention described above, the bottom surface of the hoop material that exits the fin pass roll 5 and reaches the squeeze roll 2 is regulated so as to be in a straight line, as shown in FIG. Because it is impossible to float upwards in the same figure,
The material hoop 1 maintains a normal cross-sectional shape as shown in FIG. 5a.

Therefore, since both edge portions 1a of the material hoop material 1 are shaped to sandwich the seam guide plate 7, the opening angle 10 (FIG. 2) of the material hoop material 1 is kept constant, and the balance between both edge portions 1a is maintained. Since the strength is kept constant, a good offset can be obtained without wrapping between the squeeze roll 2 portions, and both edge portions 1a are formed using the material hoop material 1 formed into a cylindrical shape.
Since the welding point 9 (FIG. 2) is maintained symmetrically right above the pipe, the welding point 9 (FIG. 2) maintains its position on the center line in the pipe manufacturing direction, and uniform welding is performed. Therefore, there is a practical effect that it is possible to obtain manufactured pipes of constant quality without variation.

[Brief explanation of the drawing]

Figure 1 is a schematic system diagram of a conventional ERW pipe manufacturing device.
Fig. 2 is an enlarged perspective view showing the last stage of the fin pass roll section of E part and D part of Fig. 1, Fig. 3 is a side view of Fig. 2, and Fig. 4 is a vertical section from A to I in Fig. 3. FIG. 5 is a diagram showing an embodiment of the present invention,
In FIG. 6, a is a vertical front view, b is a vertical side view, and FIG. 6 is a side view when the same seam guide plate as above is used. 7 is a seam guide plate, 8 is a contact part, 8a
is the sliding surface part.

Claims (1)

[Scope of utility model registration request] In a seam guide plate attached to an electric resistance welded pipe manufacturing device, the seam guide plate is formed into a plate-like body, and a curved sliding surface portion is provided at the tip abutting portion of the seam guide plate that comes into contact with the hoop material. A seam guide plate with special features.