JPS61123414A - Apparatus for producing multi-layered spiral pipe - Google Patents

Abstract

PURPOSE:To permit the easy adjustment of a clearance size and to obtain a good weld zone by applying thermal deformation to a strip and moving a strip supply table to adjust the tension of the strip thereby adjusting the clearance between the end edges of the adjacent strips. CONSTITUTION:A signal is fed from an automatic clearance detector 4 to a central control panel 16 which in turn emits an operation command to a driving machine 13 of the strip supply table 5 and the heating element of a heater D when the size of the clearance for welding between the end edges of the adjacent strips 1 approaches the limit of a permissible value.The table 5 is moved rightward by the machine 13 according to the operation command to increase the left side tension of the strip 1 and the calorific value is controlled by decreasing the current of the heating element in the heater D successively from the left toward the right when the clearance size increased. The strip 1 is curved toward the right and the clearance is narrowed. The clearance size is thus maintained always within the permissible value, at which size the winding of the strip 1 is executed. The end edges thereof are at the same time pressed and restrained by rolling down rolls 3 and are welded by an automatic welding machine 14.

Description

Detailed Description of the Invention <Industrial Application Field> The present invention relates to a multilayer spiral pipe manufacturing apparatus for forming a multilayer spiral pipe by winding a plurality of layers of strips in a spiral shape, and particularly relates to a multilayer spiral pipe manufacturing apparatus for forming a multilayer spiral pipe by winding a plurality of strips in a spiral shape. It is suitable for use in manufacturing large-diameter steel pipes for high-pressure piping, etc.

<Prior Art> Conventionally, a spiral-type pipe manufacturing apparatus has been used to manufacture thick-walled, large-diameter pipe materials. This device wraps the strip around the inner cylinder that serves as the lining and forms it into a multilayer spiral tube, so it is possible to manufacture thick, large-diameter tubes of any diameter without being limited by the width of the strip. Moreover, since it can be easily wound in multiple layers, it is generally used as a large-diameter high-pressure cylinder such as a cylinder for a high-pressure pressure vessel or a large-diameter steel pipe for high-pressure piping.

In the production of multilayer spiral pipes, good welding of the edges of adjacent strips in all layers is required, and it is necessary to maintain the gap size between the edges when winding the strips within tolerances. This is one of the important issues in obtaining a good weld. However, it is unavoidable that strips undergo meandering deformation during the manufacturing process, and slight dimensional errors in the cylindrical body around which they are wound can also affect the shape of the strip, resulting in distortion between adjacent edges of the strip when it is wound spirally. Variation occurs in the gap size, and if this deviates from the allowable value, it will not be possible to obtain a good weld.

As a pipe manufacturing device that can eliminate such defects,
A multilayer snoquiral tube manufacturing apparatus as shown in FIG. 4 has been proposed. This device includes a feeding device A that rotates an inner tube 2 around which a strip 1 is wound and moves the inner tube 2 in its longitudinal direction, a group of rolling rolls 3 that brings the strip 1 into close contact with the inner tube 2, and an adjacent roller. The winding device B is equipped with an automatic gap detector 4 between the edges of the strip 1.

A supply device C provided with a strip supply stand 5 for supplying the strip 1
It is composed of. Wrapping is done on roll group 3 of device B.
The rolling pressure of each roll can be adjusted individually. The supply device C feeds the strip plate 1 mounted on the payoff reel 6 to a leveler 7. Pinch roll8. Guide 9. The strip supply table 5 that supports these devices is supplied to the outer circumferential surface of the inner cylinder 2 through the tension roll 10 in order, and the strip supply table 5 that supports these devices is connected to a pair of racks 12 laid on a bed 11.
A pinion (not shown) in the drive unit 13 is engaged with the inner cylinder 2 so that it can move in the longitudinal direction of the inner cylinder 2.

In order to adjust the welding gap between the edges of adjacent strips 1 in this device, the gap size is detected by the automatic gap detector 4, and based on the detection result, the winding is performed on the rolling roll group of kn. The tension applied to both ends of the strip 1 is adjusted by adjusting the rolling pressure of the strip 1 and moving the strip supply table 5 of the supply device C. That is, various devices such as the automatic gap detector 4°, the rolling down device of the rolling roll group 3, the drive machine 13 of the strip steel supply table 5, and the automatic welding machine 14 provided in the winding device B, are as follows:
Central control panel 1 with built-in computer via wiring 15
6, the detection signal from the automatic gap detector 4 is input to a central control panel 16, and an operation command is issued to the rolling device of the rolling roll group 3 and the driving machine 13 of the strip supply table 5. The rolling roll group 3 is pressurized with a pressure gradient across the entire width of the strip 1 to increase or decrease the rolling pressure at both end edges of the strip 1. The strip supply stand 5 moves in the longitudinal direction of the inner tube 2 by meshing with the pinion in the drive machine 13 and the rack 12, thereby increasing or decreasing the tension on both ends of the strip 1. By using the above two means in combination, the gap between the edges of adjacent strips 1 is adjusted to maintain an appropriate value.

<Problems to be Solved by the Invention> In the conventional method for adjusting the gap at the edge of the strip in a multilayer spiral pipe manufacturing apparatus, it is difficult to maintain the gap size completely within an allowable value in response to an appropriate welding speed. In addition, if a large tension is applied to one edge of the strip, an excessively large interlayer gap (exceeding the allowable value) will occur between the wrapping and the opposite edge. there were.

In addition, for the purpose of eliminating the layer 1'd + gap of the strip, a strip heating device that can change the heating temperature at the center and both edges of the strip has been proposed, but the gap size between the edges of the strip Since the control requires a high level of skill, it is not effective in eliminating the above-mentioned variation in the gap between the end edges of the strips.

In view of the above-mentioned problems in the conventional technology, the present invention has been developed to reduce the variation in the appropriate gap size required for welding the edges of adjacent strips to each other when winding strips in a spiral manner, thereby keeping the gap size within the allowable value. It is an object of the present invention to provide a manufacturing apparatus capable of manufacturing a high-quality multilayer spiral pipe by maintaining a good welded part and minimizing the interlayer gap.

In the present invention, a means is provided for heating the strip plate fed from the feeding device toward the winding device with a temperature gradient in the width direction of the strip, and by the heating, By applying the required thermal deformation to the strip and using this thermal deformation together with the variation in tension on the strip caused by the movement of the feeding device in the conventional device described above, the winding is carried out at the adjacent edge of the inner strip. The structure was designed to maintain the welding gap size between the two parts within an allowable value.

That is, the multilayer spiral pipe manufacturing apparatus of the present invention includes a feeding device that rotates an inner cylinder around which a band plate is spirally wound and moves the inner cylinder in its longitudinal direction, and a pressing unit that brings the band plate into close contact with the inner cylinder. a winding device having an automatic gap detector for detecting a gap between a group of rolls and the adjacent end edges of the strip; and a feeding device having a strip supply stand that supplies the strip toward the inner cylinder. A multilayer spiral pipe manufacturing apparatus comprising: a supply table moving means for moving the strip supply table along the longitudinal direction of the inner cylinder; Further, the present invention is characterized in that a heating device is provided for heating the band plate with a temperature gradient in the width direction of the band plate. Here, the supply table moving means and the heating device are each connected by wiring to a central control panel having a built-in computer, and the automatic gap detector inputs its detection signal to the central control panel as in the conventional device. It is wired accordingly.

Operation> First, the specified dimensions of the gap between the adjacent edges of the strips are input into the central control panel along with various data such as the outer diameter of the inner cylinder, the thickness of the strip, and the width of the strip. Manufacturing of spiral/J spiral tubes begins in accordance with the law.

The gap between the adjacent edges of the strips to be welded is constantly monitored by an automatic gap detector, and the data is input to the central control board, which immediately analyzes the data and controls the heating device. It also issues a command to the strip supply table drive machine. Based on this command signal, the temperature gradient of the heating device is controlled to give the strip the required thermal deformation, and the position of the strip supply table is finely adjusted, and the combination of these effects reduces the variation in the gap size for strip welding. 5 adjustments are made to maintain the values within tolerances to ensure good welding by the automatic welder.

Note that the gap adjustment means by controlling the pressing force of the reduction roll group used in the conventional apparatus shown in FIG. You don't have to.

<Example> As shown in FIG. 1, which schematically shows the structure of an embodiment of the multilayer spiral pipe manufacturing apparatus according to the present invention, the inner cylinder 2 around which the strip plate 1 is wound is rotated, and the inner cylinder 2 is rotated in the longitudinal direction. A winding device B includes a feeding device A that moves the strip 1, a group of rolling down rolls 3 that pressurizes and restrains the strip 1 to the inner cylinder 2, and an automatic gap detector 4 at the edge of the adjacent strip 1; It consists of a supply device C provided with a strip supply table 5 for supplying the plate 1, and a heating device installed on the strip supply table 5 of the supply device C at a position closest to the winding device WB. There is. The above-mentioned feeding device 1A and winding device B are constructed in the same manner as in the conventional device shown in FIG. Inner cylinder 2
It can be moved in the longitudinal direction. The heating device 'tj1. D faces the lower surface of the strip 1 supplied from the strip supply table 5, and is configured to heat the strip 1 with a temperature gradient in the entire width direction. A driving machine 1 for this heating device and the supply device C
3 are each connected to a central control board 16 with a built-in computer through wiring 15, and a command signal is issued from the central control board 16 in response to input data from the automatic gap detector 4.

These operations are controlled. Note that a known automatic detector using a laser or the like is used as the automatic gap detector 4.

As shown in FIG. 2(a), which is an enlarged view of the heating device part, and FIG. 2(b), which shows its planar shape, a plurality of heating devices are arranged in rows in the width direction of the strip 1, facing each other on the lower surface of the strip 1. For example, a support base 18 on which 17 groups of heating elements such as electric resistance heating elements are arranged
is fixed on the strip supply stand 5 by legs 19. At the front and rear ends of the support stand 18, the roll 20 of the band plate support is seen as an axis.
The band plate 1 and the heating element 17 are kept at an appropriate distance, and a trap is formed so that the band plate 1 can smoothly pass over the group of heating elements 17 when being wound. Each of the plurality of heating elements 17 is connected to the wiring 15.
It is connected to the central control panel ]6 via the.

In FIG. 1, the tip of the band plate 1 is fixed to the right end of the inner cylinder 2,
The strip plate 1 supplied while rotating the inner cylinder 2 is wound up in a spiral shape while being pressurized by a group of rolling rolls 3. In this work, due to slight meandering of the strip 1, or the inner tube 2 or the wrapped steel strip 1 has already been wrapped, due to dimensional errors such as the outer diameter, roundness, straightness, etc. of the cylindrical body, When the welding gap size between the edges of the strip 1 approaches the allowable limit, a signal is sent from the gap automatic detector 4 that monitors this gap size to the central control board 16, and the central control board 16 Drive machine 13 of the strip supply table 5
An operation command is also issued to the heating element 17 of the heating device.

When the gap size becomes wider, the operation command automatically moves the strip supply table 5 to the right in FIG. In the figure, the tension on the left side of the strip 1 is increased, and the current of the plurality of heating elements 17 in the heating device is automatically decreased from the leftmost heating element to the rightmost heating element in Figure 1. The amount of heat generated is controlled according to the conditions shown in Figure 1.

A temperature gradient is provided so that the left side of the band plate 1 is high temperature and the right side is low temperature, and the gap is narrowed by curving it to the right side. vice versa,
If the gap becomes narrow during winding, the gap is adjusted by giving the band plate 1 the opposite effect on the left and right sides as described above. In this way, the gap size is always maintained within the allowable value, and at the same time as the band plate 1 is wound, its edge portion is pressurized and constrained by the reduction roll group 3, and welding is performed by the automatic welding machine 14.

As mentioned above, upon receiving the data signal from the automatic gap detector 4, the central control panel 16 instantaneously analyzes the data signal using the built-in computer, and issues commands to each heating element 17 of the heating device to perform control. However, this heating element control is performed by increasing or decreasing the supply current of each heating element 1, for example by changing the position of the trigger by phase control using a thyristor.
7 by adjusting the amount of heat generated per unit time.

The amount of deformation due to the temperature difference in the width direction of the strip plate 1 can be expressed by the following simple formula, and an approximate value thereof was confirmed as a result of experiments.

Here, b is the width of the strip, t is the heating length of the strip, α is the coefficient of thermal expansion, and ΔT is the temperature difference between both end edges.

FIG. 3(a) shows the side shape of another example of the heating device, and FIGS. 3(b) and 3(c) show the cross-sectional structure taken along the line B-B and the cross-sectional structure taken along the line C-C, respectively. By changing the distance from the heating element 17a facing the lower surface of the strip 1 to the strip 1 in the strip width direction, the strip 1 is configured to have a temperature gradient in the strip width direction. Central control panel 1
The operation command sent from 6 is given to the servo motor 21 through the wiring 15, and the servo motor 21 rotates by the required number of rotations, and the heating element 17a is attached via the pinion 22. The arc gear 24 is rotated. The heating element mounting base 23, which is pivoted to a support base 18 fixedly installed on the strip supply base 5, swings with the rotation of the arc-shaped gear 24, and the base 23 swings from the strip plate 1 at both ends thereof. The distance can be changed. The heating element 17a fixed on the base 23 is of an integrated type, and the distance between the heating element 17a and the strip plate 1 in the width direction can be changed by commands from the central control panel 16 as described above. By increasing or decreasing the amount of radiant heat applied to the strip l, a temperature gradient in the width direction of the υ plate can be created. This temperature gradient causes the strip 1 to curve slightly and adjusts the gap between adjacent edges of the wrapped strip, as in the previous embodiment.

<Effects of the Invention> According to the apparatus of the present invention, immediately before winding the strip, the heating device heats the strip with a temperature gradient in the strip width direction to give thermal deformation to the strip, and at the same time, the strip is heated by moving the strip supply table. Since the tension of the strip is harmonized and the gap between the edges of adjacent strips is adjusted by using both of these functions, it is easy to adjust the gap size, and the winding of the strip is always done to close the gap during welding. It was possible to maintain the dimensions within the allowable range and obtain a good weld. In addition, the strip plate is heated to a temperature of, for example, 100 to 200 by using a heating device.
for heating to °C.

During winding, the interlayer gap becomes smaller due to subsequent cooling shrinkage, and in addition to the above-mentioned good welding, a high quality multilayer spiral tube can be obtained.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing the appearance of an embodiment of the multilayer spiral pipe manufacturing apparatus according to the present invention, FIG. 2(a) is a side view of the heating device, FIG. 2(b) is a plan view thereof, and FIG. FIG. 3(a) is a side view showing another embodiment of the heating device, FIG. 3(b) is a sectional view taken along the line B-B, FIG. 3(C) is a sectional view taken along the line C-C, FIG. 4 is a perspective view showing an example of a conventional multilayer S/4' radial tube cleaving device. In the drawing, A is the feeding device. B is the winding device, C is the feeding device. D is a heating device. 1 is a strip plate, 2 is an inner cylinder, and 3 is a group of rolling rolls. 4 is an automatic gap detector, and 5 is a strip supply stand. 12 is a rack, 13 is a drive machine, 14 is an automatic welding machine, 15 is wiring, 16 is a central control panel, and 17.17a is a heating element.

Claims (1)

[Claims] A feeding device that rotates an inner cylinder around which a strip is spirally wound and moves the inner tube in its longitudinal direction, a group of rolling rolls that brings the strip into close contact with the inner tube, and adjacent edges of the strip. A multilayer spiral pipe manufacturing apparatus comprising: a winding device having an automatic gap detector for detecting a gap between the parts; and a feeding device having a strip supply stand that supplies the strip toward the inner cylinder. a supply table moving means for moving the plate supply table along the longitudinal direction of the inner cylinder; 1. A multilayer spiral tube manufacturing device, characterized in that it is equipped with a heating device that heats the tube by heating the tube.