JP2008073753A - Method for rolling tube stock in cold pilger mill - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for continuously rolling a tube stock in the rolling in a cold Pilger mill. <P>SOLUTION: In the method for rolling the tube stock in the cold Pilger mill, a preceding tube stock to be rolled is rolled by the length of a succeeding tube stock to be rolled, a feed stand is retracted, the succeeding tube stock is inserted, and the feed stand is advanced toward a roll die before starting the automatic rolling. When the feed stand hits a rear end of the succeeding tube stock, a pressure switch installed on the feed stand is not operated and the feed stand is continuously advanced. When a fore end of the succeeding tube stock hits a rear end of the preceding tube stock, the pressure switch is operated to detect that the fore end of the succeeding tube stock hits the rear end of the preceding tube stock and the feed stand is stopped. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a continuous pipe rolling method in cold pilger mill rolling.

  Conventionally, when continuously rolling a raw pipe with a cold pilger mill, a raw pipe (hereinafter referred to as a “pre-rolled raw pipe”) to be rolled first is subsequently rolled (hereinafter referred to as a “next rolling raw pipe”). ”), The rear end face of the pre-rolled blank tube is pushed by the next roll blank, so that the length of the next roll blank is rolled. The tip of the next rolled raw tube is inserted so that there is no gap with the rear end of the preceding rolled raw tube when it is inserted, but due to an error in measuring the length of the next rolled raw tube, When there is a gap between the pipe and the pipe, it becomes pneumatic drawing (rolling the same part many times), and a locally thin part (hereinafter referred to as “local thickness is small”) occurs.

  As the above countermeasure, for example, as disclosed in Japanese Utility Model Laid-Open No. 60-66602 (Patent Document 1), one of the sheep wires hung between two sheep spaced apart beyond the movable length of the feed base. A predetermined position on the side and the feed base are connected by a connecting rigid body, and a material detection sensor is attached to a predetermined position on the opposite side of the sheep wire via another connecting rigid body, and kicked on the companding line with the tip aligned. A cold pill that detects from the front end to the rear end of the waiting waiting tube for companding as the compensator feed of the feed base, automatically stops companding simultaneously with the detection of the rear end, and feeds the waiting mother tube Garmill has been proposed.

Further, as disclosed in Japanese Utility Model Laid-Open No. 60-66603 (Patent Document 2), a rod body extending backward is attached to a feed base, and a material detection sensor is attached to the rear end of the rod body. The material detection sensor faces the rear end of the standby mother pipe that has been kicked in with the rear end when it is retracted to the retreat limit. A cold pilger mill has been proposed in which the drawing is automatically stopped and the standby mother pipe is fed at the same time.
Japanese Utility Model Publication No. 60-66602 Japanese Utility Model Publication No. 60-66603

  However, in the above-mentioned Patent Document 1 or 2, first, if the retracting limit of the feed base is set in accordance with the length of the longest mother pipe in the irregular mother pipe lot to be drawn, the rest is automatically It is said that there is no useless space between the leading mother pipe because it stops by drawing and stopping the length of the standby mother pipe that has been kicked with the tip aligned, and the local wall thickness Unlike the problem to prevent the occurrence of small defects, it is not a countermeasure for that.

  In the present invention, unlike the above-mentioned patent documents, in order to prevent the occurrence of defects with small local thickness, the inventors have made extensive developments. The drawn tube is rolled by the length of the subsequent drawn tube. Then, when the leading end of the next rolled raw tube is inserted, it is inserted so that there is no gap between the rear end of the preceding rolled raw tube. It is stretched and a defect with small local thickness occurs. Therefore, the present invention provides a method for rolling a pipe in a cold pilger mill that prevents the occurrence of a local small thickness defect by a pipe insertion method in which a gap between the pipes does not occur.

The gist of the invention is that
(1) In the rolling method of the raw pipe by the cold pilger mill, after rolling the preceding rolling raw pipe for the length of the next rolling raw pipe, the feed base is moved backward to insert the next rolling raw pipe and automatically rolling. When the feed base moves forward toward the roll die and hits the rear end of the next rolling base tube before entering, the pressure switch installed on the feed base does not operate and the feed base continues to advance, and then the next rolling base When the tip of the pipe hits the rear end of the preceding rolling base pipe, the pressure switch is activated to detect that the front end of the next rolling base pipe hits the rear end of the preceding rolling base pipe, and the feed base stops. A raw pipe rolling method in a cold pilger mill characterized by comprising.
(2) A method for rolling a cold pipe with a cold pilger mill, characterized in that a gap between the tip of the next rolling blank and the rear end of the preceding rolling blank is eliminated.

  That is, as described above, the principle that the pressure switch does not work at the first contact and the switch is turned on at the later contact is because the next rolling element tube is not fixed in the former, the sensor is the rear end of the tube. The impact force when it hits is small because it starts moving as soon as it hits, but in the latter, the impact force received by the sensor is large because the pre-rolled blank is fixed by a roll stand. By utilizing this difference in impact force, it is installed so that a stop signal is not sent to the feed base in the former case, and a stop signal is sent in the latter case so as to control the advance and stop of the feed base. It is a thing.

  As described above, before inserting the blank tube according to the present invention and entering automatic rolling, the feed base moves forward to eliminate the gap between the blank tube and the blank tube so that automatic rolling can be performed smoothly. It is possible to eliminate the occurrence of defective products due to the thinning of the tube end portion that stretches the sheet, and it is possible to improve productivity and yield.

Hereinafter, the present invention will be described in detail with reference to the drawings.
FIG. 1 is a side sectional view showing a cold pilger mill line. As shown in the drawing, as a process of drawing the element tube, the element tube 1 is kicked into the standby position on the line with the front end aligned or the rear end aligned and is waiting. First, the forward feed of the standby element tube 1 is performed by stopping the drawing of the preceding element tube 1 ′ or the preceding element tube 1 ″ halfway. Next, when the pusher 2 pushes the raw tube 1, the mandrel bar clamper 3 opens and passes through the raw tube 1. The push plate 6 is pushed open to advance, and stops when the rear end is just in front of the push plate 6, and the pusher 2 moves backward.

  Next, although the drawing is performed, the feeding of the drawing base 5 is synchronized with the reciprocating drive cycle of the drawing roll 7, and the raw tube 1 is intermittently sent while the drawing roll 7 returns. It is like that. Accordingly, the drawing base 5 reaches the rear end of the blank tube 1 by the unloaded reciprocating driving (idle driving) of the drawing roll 7 for the first few times, and further, the drawing roll 7 is idled for a while. The actual companding is resumed only when the tip of the element tube 1 hits the rear end of the preceding element tube 1 ′ and advances it. Drawing is performed by rotating the rolls with two tapered grooves on the mandrel 8 in the center in the horizontal direction. The raw tube 1 is rotated by the rotating chucks 9 and 10 before and after the drawing roll 7. As described above, the raw pipe is fed and drawn, and the preceding raw pipe is drawn by the advance of the drawing base by the length of the preceding raw pipe.

  FIG. 2 is a schematic view showing a state in which a gap between the preceding element tube and the next element tube is generated. As shown in this figure, when the gap 11 between the preceding element tube 1 ′ and the next element tube 1 is vacant, the element tube is drawn by the drawing / feeding base 5 until the gap between the preceding element tube 1 ′ and the next element tube 1 disappears. Since 1 cannot be advanced, the drawing roll die 13 provided in the roll stand 12 moves many times in the same place. If it does so, only the thickness will become thin and it will become the cause which a defective product with a small local thickness will generate | occur | produce.

  FIG. 3 is a diagram illustrating a step of advancing the companding feed table when inserting a blank tube according to the present invention. FIG. 3A is a view showing a state before inserting a raw tube, FIG. 3B is a view showing a state in which the raw tube is inserted, and FIG. It is a figure which shows a state. As shown in FIG. 3 (a), prior to the insertion of the tube, the preceding tube 1 'is fed by the companding feed base 5, and the next tube 1 is in a standby state.

  FIG. 3 (b) shows a state in which the preceding element tube 1 ′ is fed by the companding feed base 5, and the next element pipe 1 is further fed by the companding feed base 5 and inserted by the companding feed base 5. Yes. In this case, the tip of the drawn tube 1 is inserted so that there is no gap 11 with the rear end of the preceding drawn tube 1 'when inserted. A gap 11 is formed between the tube 1 '. As a result, this gap affects the local thickness of the drawn product. Reference numeral 14 denotes a distance by which the companding feed base moves forward by a gap.

  In this way, the crushing feed base moves forward by the gap, thereby eliminating the gap 11 between the leading end of the next rolling element tube 1 and the rear end of the preceding rolling element tube 1 ′. If there is this gap, the locally stretched product becomes thin and loses its value as a product, so that the local part is cut or discarded. Therefore, it inserts so that the space | interval may be eliminated.

  FIG. 3 (c) is a plan view of FIG. 3 (b) in order to eliminate the gap 11 between the companding tube 1 and the preceding companding tube 1 ′, which affects the local thickness of the above-described drawn product. The companding feed base 5 moves forward to clog the gap 11 between the preceding companding tube 1 'and the next companding tube 1 by advancing the companding feed table 5 only by the gap indicated by The advancement distance of the companding feed base 5 is such that the pressure switch 15 attached to the companding feed base operates and the preceding companding tube 1 'and the next companding tube 1 are in contact with each other. It is configured to perform an operation to automatically stop.

  Note that a material detection sensor for the pressure switch 15 attached to the drawing / feeding base 5 and an automatic drawing / stopping circuit for the drawing based on the signal are based on a normally used device. According to the continuous pipe rolling method in the cold pilger mill rolling according to the present invention configured as described above, before the raw pipe is inserted and automatic rolling starts, the feed base moves forward and the gap between the raw pipe and the raw pipe The automatic rolling can be carried out smoothly, eliminating the local wall thickness at the end of the tube that squeezes the raw tube, thereby eliminating the occurrence of defective products and improving productivity and yield. This is very advantageous in industry.

It is side surface sectional drawing which shows a cold pilger mill line. It is the schematic which shows the state in which the clearance gap between a preceding element pipe and a next element pipe arises. It is a figure which shows the advance process of the companding feed stand at the time of the raw tube insertion concerning this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Element pipe 1 'Leading element pipe 1''Leading element pipe 2 Pusher 3 Mandrel bar clamper 4 Mandrel bar 5 Feed base 6 Press plate 7 Drawing roll 8 Mandrel 9, 10 Rotating chuck 11 Gap 12 Roll stand 13 Drawing roll Dice 14 Distance that the companding feed base moves forward by the gap 15 Pressure switch


Patent Applicant Sanyo Special Steel Co., Ltd.
Attorney Atsushi Shiina

Claims (2)

In the rolling method of the pipe by the cold pilger mill, after rolling the preceding rolling blank for the length of the next rolling blank, before retracting the feed base and inserting the next rolling blank to start automatic rolling In addition, when the feed base advances toward the roll die and hits the rear end of the next rolling raw tube, the pressure switch installed on the feed base does not operate and the feed base continues to advance, and then the leading end of the next rolling base pipe. When the pressure switch hits the rear end of the preceding rolling element tube, the pressure switch is activated to detect that the tip of the next rolling element tube has hit the rear end of the preceding rolling element tube, and the feed base stops. A raw pipe rolling method using a cold pilger mill. A blank pipe rolling method in a cold pilger mill, wherein a gap between the tip of the next roll blank according to claim 1 and the rear end of the preceding roll blank is eliminated.

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