JPS624337Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a device for preventing rolling during forming of an ERW steel pipe using a cage forming method.

As shown in Fig. 1, the electric resistance welded steel pipe produced by the cage forming method is produced by sequentially forming a steel strip S into a cylindrical shape using a breakdown roll 1, an edge forming roll 2, an outside cage roll 3, and an inside cage roll 4. And Finpas Roll 5
After final forming the raw pipe P into a predetermined shape and size while applying circumferential reduction, the joint edge portion Pe of the raw pipe P is heated with high frequency, and it is manufactured by upset welding using a squeeze roll.

When forming raw pipes for ERW steel pipes, the steel strip may sway sideways while running, so-called rolling. To prevent this, when forming raw pipes using the roll-forming method, the circle of the steel strip is In order to strengthen the restraint in the circumferential direction, the rolling force of the breakdown rolls is increased, semi-cage rolls are arranged between the breakdown roll stands, and simple edge guide rolls are provided.

However, when forming the blank tube using the cage forming method, there is a problem that the width of the breakdown roll 1 in the cage zone cannot be increased due to the conflict with the outside cage roll 3 and the inside cage roll 4. Therefore, the restraint of the steel strip S in the circumferential direction by the breakdown roll 1 in the cage zone could not be expected to be very effective.

In addition, a feature of the cage forming method is that a large number of small-diameter outside cage rolls 3 are arranged in series to continuously restrain the edge portion Pe of the steel strip S and the raw pipe P in the longitudinal direction. It is impossible to install a large number of rolls due to the equipment, and therefore there have been few measures to prevent rolling during the cage forming method.

The present invention makes it possible to effectively prevent rolling during molding of blank tubes using the cage forming method by using relatively simple means without significantly modifying existing equipment.

An example of an embodiment of the present invention will be described below with reference to FIGS. 2 and 3.

First, in FIG. 2, reference numeral 6 denotes the left and right stands of the outside cage roll 3. This outside cage roll stand 6 is located approximately in the center of the cage zone, and from that part there are a set of left and right outs. The side cage roll 3 is removed, and in its place is a bracket 7 fixed to a stand 6, and a roll holder provided vertically slidably relative to the bracket 7 via a motor 8, a chain 9, and a worm shaft 10. 11
A pair of left and right anti-rolling devices are provided, each consisting of a large-diameter edge presser roll 12 rotatably supported by the roll holder 11.

Further, in FIG. 3, reference numeral 13 denotes a stand for the inside cage roll 4. This inside cage roll stand 13 is located at the rear of the cage zone, and from this stand 13, a set of left and right inside cage rolls 4 are installed. removed,
Instead, a bracket 14 is fixed to the stand 13, and a roll holder 1 is provided vertically slidably relative to the bracket 14 via a motor, chain, and worm shaft (not shown).
5 and a large-diameter edge presser roll 16 rotatably supported by the roll holder 15.

The reason why the diameters of the edge pressing rolls 12 and 16 are made large is to increase the amount of rolling correction at one location.

In other words, increasing the number of edge presser rolls 12 and 16 will reduce the number of outside cage rolls 3 or inside cage rolls 4, which is not preferable in terms of pipe forming, and the number of edge presser rolls 12 should be as small as possible. , 16 to effectively correct rolling.

After adjusting the width and height of the outside cage roll stand 6 and the inside cage roll stand 13 according to the outer diameter dimension of the ERW steel pipe to be manufactured, the height of the edge presser rolls 12 and 16 is adjusted. Then, as shown in Fig. 2, the left and right edge parts Se and the third edge part of the arc-shaped steel strip S are
As shown in the figure, the left and right edge portions Pe of the raw pipe P, which is formed into a substantially cylindrical shape, are each pressed with an edge presser roll 1.
2 and 16 are used to forcibly prevent rolling during molding of the raw tube.

Note that the lower surface of each edge presser roll 12, 16 is
Set the edge Se of the base pipe P 20 to 30 mm higher than the reference line of the edge Pe of the raw pipe P.

By setting the height position of each edge presser roll 12, 16 in this way, when rolling occurs,
Only the edge portion Se at the tip of the arc-shaped steel strip S or the edge portion Pe at the tip of the blank pipe P hits the edge presser roll 12 or 16 to correct the rolling, and the other edge portions are unless the camber of the edge presser roll 12 or 16 is abnormally large, the edge presser roll 12 or 1
The edge distortion that occurs during the rolling correction in step 6 is only at the tip of the formed raw pipe P,
That part is never used as an open part for products, and there is no risk of distortion occurring at the edges over the entire length of the raw pipe.

As described above, the present invention includes a pair of large-diameter left and right edge presser rolls supported by outside cage roll stands and one large-diameter edge presser roll supported by inside cage roll stands in the cage zone. As a result, rolling during forming of an ERW steel pipe by the cage forming method can be effectively prevented by using a small number of the edge presser rolls, and there is no need for strong pressure from a breakdown roll. There is no need to install multiple edge guide rolls.

[Brief explanation of the drawing]

Fig. 1 is a schematic plan view of a stand for forming ERW steel pipes using the cage forming method to which the present invention is applied, and Fig. 2 is a front view of the anti-rolling device of the present invention installed on an outside cage roll stand. , FIG. 3 is a front view of the anti-rolling device of the present invention installed on the inside cage roll stand.

Claims (1)

[Claims for Utility Model Registration] A bracket 7 fixed to the outside cage roll stand 6 is provided in the cage zone, and a roll holder 11 is provided to be vertically slidable with respect to the bracket 7 via a drive mechanism. , a pair of left and right rolling prevention devices consisting of a large diameter edge presser roll 12 rotatably supported by the roll holder 11; a bracket 14 fixed to the inside cage roll stand 13; It is characterized by being provided with a rolling prevention device consisting of a roll holder 15 provided to be vertically slidable via a drive mechanism, and a large diameter edge presser roll 16 rotatably supported by the roll holder 15. Rolling prevention device when forming raw ERW steel pipe using cage forming method.