JP5758080B2 - Coil carrier cart and coil carrier method - Google Patents

Description

  The present invention relates to a coil transport carriage and a coil for inserting a coil wound loosely, in particular, a coil of a directional electrical steel sheet that has been subjected to high-temperature finish annealing with a large degree of looseness into an unwinding reel on the entry side of a flattening annealing facility. It is the technique regarding the conveyance method.

In high-temperature finish annealing of grain-oriented electrical steel sheets, after the annealing separator is applied to the surface, the direction of the coil is changed to a hole and annealing is performed at a high temperature. After high-temperature annealing, the direction of the coil is changed to the side of the hole again and processed in the next leveling annealing equipment, but the coil is wound in a very loose state. Since the shape of the coil is changed to the side of the hole, the shape (hole diameter and outer diameter) of the coil must be deformed (collapsed).
For this reason, the coil is deformed on the coil carrier carriage inserted into the coil unwinding reel on the entrance side of the flattening annealing equipment, the shape of the coil hole is greatly deformed, and the axis of the coil unwinding reel is changed. There was no gap between the outer diameter and the coil hole, and it was not easy to unwind the coil and insert it into the shaft of the reel, and it was extremely difficult to insert it automatically. In order to perform this operation, it was necessary to manually correct the shape of the coil using a jig or to repeat the operation many times. Therefore, it takes a lot of manpower, and it takes a lot of time to handle the coil on the entry side. Due to the limitation of the handling time, the processing speed of the steel plate in the smooth annealing equipment cannot be increased, and it is not a small scale equipment. Cost was a problem.

There is a technique as described in (1) or (2) below.
(1) A technique is known in which a coil fall prevention stopper that can be moved up and down at the front and rear end portions in the traveling direction is provided in the traveling direction of the coil transport carriage (see, for example, Patent Document 1).
(2) The angle of the coil mount with respect to the horizontal is set to 45 ° to 55 °, the location supporting the coil's own weight is only two inclined portions, and control within this range corrects deformation due to coil collapse. The technique which performs is also known (for example, refer patent document 2).

Utility Kaihei 06-39214 JP 2006-281306 A

However, in the case of the technique (1), the coil conveyance carriage is provided with a coil fall prevention stopper that can be moved up and down at the front and rear end portions in the movement direction toward the movement direction of the coil conveyance carriage. It does not have a function of correcting the deformation of the shape and is not effective at all for correcting the deformation of the coil.
In the case of the technique (2), only the two inclined portions support the coil's own weight, and it is structurally difficult to apply to the coil carriage, and the size of the coil (outer diameter) It is not a technology for changes.
As described above, there is a problem in the coil transport cart corresponding to the suppression of the deformation of the shape with respect to the loose coil, but a definite measure is not taken. It is not possible to carry the coil into the flattening annealing facility (insertion into the coil unwinding reel) by the transfer device. Generally, the coil is lifted from the outside with a hanging cloth, and the cone is inserted and fixed from both ends of the coil hole. It was only used for corn-type coil unwinding reels.
For this reason, coil loading cannot be automated, resulting in an increase in cost and insufficient safety.
Then, the objective of this invention is correcting the deformation | transformation of the shape of the coil from which a coil diameter differs, and providing the coil conveyance trolley | bogie and the coil conveyance method which can carry in the coil automatically to the planarization annealing equipment.

The gist of the present invention for solving the above problems is as follows.
(1) In a coil transport carriage equipped with a coil skid for loading a coil and capable of traveling on a rail, the coil is wound after an annealing separator is applied to the surface, and thereafter, high-temperature finish annealing is completed. It is a coil of grain-oriented electrical steel sheet,
A coil skid lifting / lowering support mechanism for supporting the coil skid to freely move up and down;
Coil deformation correction arms provided with base ends pivotably provided on the left and right sides of the coil skid in the direction of travel of the coil transport carriage, and with tip ends facing each other so as to move toward or away from each other. When,
A correction load control means for controlling the correction load applied to the coil by the opposing coil deformation correction arm;
The correction load control means makes the coil thickness dimension, sheet width dimension and material constant.
As a variable having the outer diameter of the coil as a parameter, the correction load applied to the coil by the coil deformation correcting arm and the short diameter when the coil hole is elliptical (hereinafter referred to as the minimum diameter of the coil hole). Seeking a relationship with
A coil conveying carriage characterized in that a correction load at which the minimum diameter of the coil hole is larger than the outer diameter of the coil unwinding reel is set as the optimum correction load in the above parameters.
(2) When the curvature radius of the cross section of the contact surface with the coil at the tip of the coil deformation correcting arm is R and the curvature radius of the coil outer diameter is RO, the value of R / RO is at least 0.95. The coil transport cart according to (1), wherein
(3) A coil conveying method, wherein the coil conveying carriage according to (1) or (2) is conveyed while correcting the deformation of the coil.
(4) The coil load dimension and the coil hole applied to the coil by the coil deformation correcting arm and the coil hole are elliptical, with the coil thickness dimension, the sheet width dimension, and the material being constant and the outer diameter of the coil as a parameter. The relationship with the short diameter (hereinafter also referred to as the minimum diameter of the coil hole) when
The correction load at which the minimum diameter of the coil hole is larger than the outer diameter of the coil unwinding reel is the optimum correction load in the above parameters,
The coil conveying method according to (3), wherein the coil is straightened with the optimum straightening load at the parameter.

According to the present invention, in a grain-oriented electrical steel sheet that is wound after being applied to the surface with an annealing separator, and subsequently subjected to high-temperature finish annealing, the deformation of the coils with different coil diameters is corrected, and the coil conveying carriage is flattened. It can be smoothly inserted into the coil unwinding reel on the entry side of the chemical annealing equipment. This makes it possible to insert the coil into the coil unwinding reel on the inlet side of the smoothing annealing facility of the coil in a short time and without manpower, and increase the speed and size of the smoothing annealing facility. Cost reduction is possible.

It is a figure which shows the outline | summary of the coil conveyance trolley | bogie which has the coil deformation correction function of a coil by this invention, and the correction method of a coil deformation | transformation. It is a figure which shows the outline | summary of the coil conveyance trolley | bogie which has the coil deformation correction function of a coil by this invention, and the correction method of a coil deformation | transformation. It is a figure which shows the outline | summary of the coil conveyance trolley | bogie which has the coil deformation correction function of a coil by this invention, and the correction method of a coil deformation | transformation. It is a figure which shows the outline | summary of the correction method of the small and large coil diameter by the coil conveyance trolley | bogie which has the coil deformation correction function of the coil by this invention. It is a figure which shows the outline | summary of the correction method of the small and large coil diameter by the coil conveyance trolley | bogie which has the coil deformation correction function of the coil by this invention. It is the figure which showed insertion of the coil to a coil unwinding reel using the coil conveyance trolley | bogie by this invention. It is a partial longitudinal cross-sectional view which expands and shows a part of FIG. It is the figure which showed an example of the relationship between the coil outer diameter of a coil, and the pressing force of the arm for coil deformation correction.

The present inventors examined a method of correcting the deformation of the coil 1 in a state in which the coil 1 that has been subjected to high-temperature finishing of a grain-oriented electrical steel sheet having a large degree of looseness is in a state beside the hole. As a result, it has been clarified that the hole of the coil 1 can be made close to a perfect circle by pressing and correcting the outer peripheral surface of the coil with the coil deformation correcting arm 31 having a pressing surface with a circular arc in section. Various modifications were made to the shape and pressure of the arm to be corrected for the coils 1 having different outer diameters, and the present invention was achieved.
Hereinafter, the present invention will be described in detail with reference to the drawings.

  The outline | summary of the coil conveyance trolley 2 which has the coil deformation correction function of the coil 1 by this invention is shown in FIGS.

The coil transport carriage 2 of the present invention is large and has the following four functions.
(1) Function for loading the coil 1 (2) Coil skid lifting / lowering support function for supporting the coil skid to be moved up and down (3) Coil deformation correction function (4) Function for running the coil transport carriage

(1) Function of loading the coil 1: The coil 1 is directly loaded, the shape of the lower part of the coil is maintained, and the material is made of a non-ferrous material (for example, a fiber-reinforced hard rubber material or A coil skid pad 22 made of a non-ferrous metal material, and a coil skid 21 that supports the load of the coil skid pad 22. The coil skid pad 22 is attached to the upper part of the coil skid 21.
The coil skid 21 is provided on the carriage coil transport carriage frame 11 and has a groove extending in a direction perpendicular to the traveling direction, and a coil deformation correcting arm opening / closing cylinder 33 described later is provided in the groove portion. It can be placed.

(2) Coil skid lifting / lowering support function for supporting the coil skid so that the coil skid can be moved up and down: An extendable lifting cylinder 15 including a hydraulic jack that lifts and lowers the coil skid 21 with the coil 1 loaded thereon, and the lifting cylinder 15 is coiled. Elevating cylinder trunnion 16 and elevating cylinder mounting bracket 17 attached to the carriage frame 11, elevating cylinder guide rod 18 for guiding expansion and contraction of the elevating cylinder 15 so that the coil skid 21 can be moved up and down smoothly (vertical), and the elevating cylinder guide rod 18 And a lifting cylinder guide rod guide bracket 19 for attaching to the coil carrier carriage frame 11 constitutes a main part.
In the above embodiment, the coil skid lifting support mechanism for supporting the coil skid so as to be movable up and down is an extendable telescopic mechanism that is installed on the coil transport carriage frame 11 and connected to the coil skid via the lifting cylinder trunnion 16 and the lifting cylinder mounting bracket 17. A main part is constituted by an elevating cylinder 15 and an elevating cylinder guide rod guide bracket 18 on the coil transport carriage frame 11 side.
The lift cylinder 15 is attached to the coil transport carriage frame 11 by fixing the lift cylinder mounting bracket 17 that supports the lift cylinder trunnion 16 attached thereto to the coil transport carriage frame 11. The lifting cylinder guide rod guide bracket 19 is fixed to the lifting cylinder mounting bracket 17.

(3) Coil deformation correction function: positioned perpendicular to the traveling direction (traveling direction) of the coil transport carriage 2 on both sides of the coil skid 21 with the coil 1 loaded, and from the both sides of the outer periphery of the coil 1 to the coil 1 A load is applied so as to embrace this, and the deformation of the outer diameter and the inner diameter of the coil 1 is corrected, and the coil is made of a non-ferrous material so that the coil 1 is not wrinkled. The arm pad 32, the coil deformation correction arm 31 that supports the load of the coil deformation correction arm pad 32, the coil deformation correction arm opening / closing cylinder 33 that applies pressure to the coil deformation correction arm 31, and the coil deformation correction arm 31 Is constituted by an arm opening / closing cylinder fulcrum pin 34 for correcting coil deformation for moving in a circular arc shape.
In the coil skid 21, the base end side of the coil deformation correcting arm 31 is provided on both the left and right sides in the traveling direction of the coil transport carriage so as to be rotatable by the fulcrum pin 34 having a horizontal axis. The distal end sides of the arm 31 are provided so as to face each other so as to be movable toward or away from each other.
The cylinder side and the piston side of the coil deformation correction arm opening / closing cylinder 33 are connected to the intermediate part of the coil deformation correction arm 31 facing each other with a gap through a horizontal axis provided at the same level. By extending (or shortening) the coil deformation correcting arm opening / closing cylinder 33, the leading end side of each of the opposing coil deformation correcting arms 31 is moved in the direction of separating (approaching). If the center of gravity of each of the coil deformation correction arms 31 is positioned outside the center of the fulcrum pin 34 in the cart width direction, the coil deformation correction arms 31 can be prevented from tilting inward. Moreover, in order to prevent the inward tilting of each coil deformation correcting arm 31, each coil deformation correcting arm 31 may be rotatable only within a predetermined angle range. Further, an intermediate portion of one or both of the coil deformation correction arms 31 and the coil transport carriage frame 11 are connected to each other by means of a telescopic cylinder (not shown) via a horizontal axis, so that each coil deformation correction arm 31 is predetermined. In addition, a connecting structure using a telescopic cylinder (not shown) may be added so as to be interlocked with the operation of one of the coil deformation correcting arms 31 shown in the figure. The tilt of each coil deformation correcting arm 31 may be prevented from being tilted.
The distal end portion of the coil deformation correcting arm 31 has a cross-sectional arc shape, and a coil deformation correcting arm pad 32 having a cross-sectional arc shape is attached to that portion.
The pressure for pressurizing the fluid supplied to the coil deformation correcting arm opening / closing cylinder 33 is variable and can be set freely (not shown).
As the pressurization method, pressure oil using a known hydraulic pump may be used, and a proportional solenoid valve is often used as a measure to make the hydraulic pressure variable, but the hydraulic pump and proportional solenoid valve It is not limited to the method.
The correction load applied to the coil 1 by the opposing coil deformation correction arm 31 is controlled by correction load control means by controlling the amount of expansion / contraction of the coil deformation correction arm opening / closing cylinder 33.
Further, the curvature radius R of the contact surface of the coil pad for correcting coil deformation 32 with the outer peripheral portion of the coil 1 is R / Ro = 0.95 or more, where Ro is the curvature radius of the coil outer diameter. This is because when R / Ro <0.95, the coil deformation correcting arm pad 32 is in local contact with the outer periphery of the coil and is wrinkled. Further, when R / Ro is 1.3 or more, the coil deformation correcting arm becomes too long in the coil passing plate direction and the machine length becomes too long compared with the coil outer shape, which is not practical. Therefore, it is preferable that 0.95 ≦ R / Ro and 0.95 ≦ R / Ro < 1.3.

(4) A function of running the coil carrier cart: The coil skid 21 in which the coil 1 is loaded receives a load from the coil car frame 11 via the elevating cylinder, and receives the wheel shaft 13 attached to the coil car frame 11. Driven (not shown), the wheel 12 is driven on the rail (rail 9). The driving method of the wheel shaft 13 is generally an electric type, but is not particularly limited by a hydraulic cylinder method or other methods.

The optimum load applied to the coil deformation correcting arm 31 varies depending on the plate thickness, plate width, material, and outer diameter of the coil 1. Therefore, it is necessary to obtain an optimal load in advance. When the outer diameter of the coil 1 is increased, the influence on the collapsed surface of the coil is increased with an increase in the weight of the coil itself.
FIG. 8 shows a test example of the deformation correction result when the thickness of the coil 1, the width of the plate, and the material are changed as variables having the constant thickness and the outer diameter of the coil as parameters.

  The coil 1 used in the test is a high-temperature finished coil of a directional electromagnetic steel sheet having a plate thickness of 0.27 mm, the coil inner diameter (d2) is 610 mm (round circle conversion), the plate width dimension is 1270 mm, and the outer diameter. (Equivalent to a true circle) was 1500 to 2100 mm. The radius of curvature of the coil deformation correcting arm 31 was 1100 mm.

  In general, the coil unwinding reel 41 on the entrance side of the flattening annealing equipment has an expansion / contraction function, and when the coil 1 is inserted into the coil unwinding reel 41, the coil unwinding reel 41 is moved from the coil inner diameter. When the coil 1 is unrolled by being reduced by about 20 mm to 40 mm, the coil unwinding reel 41 is expanded to a degree slightly larger than the coil inner diameter. Since the difference in diameter from the reduction to the enlargement affects the strength of the unwinding reel (the reel core becomes thin), it is generally about 20 to 40 mm.

In this test, the allowable limit of the difference between the outer diameter (D1) of the coil unwinding reel 41 and the minimum diameter of the hole of the coil 1 was 20 mm. The outer diameter (D1) of the coil unwinding reel 41 at that time is 590 mm, the shortest distance in the diameter direction of the coil hole is 590 mm or more is acceptable (●), less than 590 mm is unacceptable, Indicate that the hole in coil 1 is horizontally long (in the case of insufficient correction; in FIG. 8, the shape correction has not been achieved) is indicated by ▲, and the hole in coil 1 that is vertically long (in the case of excessive correction) is indicated by ◆. doing.
From this test result,
(1) For the coil 1 having a constant coil outer diameter, when the pressing force of the coil deformation correcting arm 31 is increased, the correction is insufficient with respect to collapse of the deformation (the hole is an ellipse with a long horizontal direction). Therefore, the shape of the inner circumference of the coil 1 approaches a perfect circle. At this time, the difference between the outer diameter (reduced state) of the coil unwinding reel 41 and the minimum diameter of the hole of the coil 1 is 20 mm or less, and the coil 1 can be inserted into the coil unwinding reel 41. Further, when the pressing force of the coil deformation correcting arm 31 is increased, the shape is excessively corrected with respect to the collapse of the shape (the inner periphery is an ellipse whose vertical direction is long), and the coil 1 is again unwound by the coil. It becomes difficult to insert into 41.
(2) It can be seen that the coil inner diameter (d2) remains constant at 610 mm (converted to a perfect circle), and the outer diameter of the coil 1 increases and the optimum load (correction gripping load) increases.
Of the above, no wrinkles were generated on the pressed coil side in the range of the pressing force of the coil deformation correcting arm 31 as a target.
In addition, since the deformation (collapse) due to the weight of the coil 1 is affected by the coil material (strength physical properties), the plate thickness, etc., the deformation correction arm pressing force (or correction) optimal for correcting the shape of each coil. The load is determined by testing in advance in consideration of the outer diameter of the coil, the material (strength physical properties), the plate thickness, the coil width, and the like.
Table 1, the occurrence of defects of the ratio (R / RO) and a coil outer circumferential portion of the curvature radius of the contact surface of the curvature of the coil outer diameter radius (RO) and the coil of the coil deformation orthodontic Amupa' de 32 (R) A survey example is shown.
Were investigated with a radius of curvature 800~1300mm the contact surface with the coil of the coil deformation orthodontic Amupa' de 32. The coil used in the test is a high-temperature finished coil of a directional electromagnetic steel sheet having a thickness of 0.23 mm. The coil inner diameter is 610 mm (converted into a perfect circle), the width is 1270 mm, and the curvature radius of the outer diameter is 1050 mm. And 800 mm.
When R / RO <0.95, wrinkles are generated on the outer periphery of the coil.

[Example]
[Example 1]
A coil 1 having a thickness of 0.27 mm and finished with a high temperature coil 1 (coil inner diameter is 610 mm (converted into a perfect circle), sheet width is 1255 mm, outer diameter (converted into a perfect circle) is 2020 mm), Coil transport bogie (see FIGS. 1 to 3 and FIG. 4: the radius of curvature of the arm pad 32 of the coil deformation correcting arm 31 is 1100 mm), and the coil unwinding reel of the smoothing annealing equipment (FIG. 6) 41.

As shown in FIG. 1, the coil 1 is loaded on the coil skid pad 22 of the coil transport carriage with a crane (not shown). At this time, the shape of the inner periphery of the coil was an ellipse having a long horizontal direction of 650 mm in the horizontal direction and 575 mm in the vertical direction. In this state, the hydraulic pressure is gradually applied to the coil opening / closing arm opening / closing cylinder 33 to close the coil deformation correcting arm 31 and the coil deformation correcting arm 31 facing the coil deformation correcting arm fulcrum pin 34 as the center. is brought closer to pivot in the direction, it is brought into contact with the outer peripheral surface of the coil 1 via the coil deformation orthodontic Amupa' de 32 (see FIG. 2). Furthermore, by operating the hydraulic pressure of the leveling opening and closing cylinder 33 to the pressing force 345KN, by adding a load (corrected load) to the coil 1 via the coil deformation orthodontic Amupa' de 32 by the coil the leveling arm 31, the shape of the coil The shape of the inner circumference of the coil was corrected to a substantially perfect circle with a horizontal direction of 599 mm and a vertical direction of 631 mm.

In a state where the coil 1 is corrected by the coil deformation correcting arm 31 through the coil deformation correcting arm pad 32, the wheel 12 of the coil transport carriage is driven by the driving device so that the rail 9 is moved to the coil unwinding reel 41. And is transported to the vicinity of a coil unwinding reel (coil rewinding reel) 41. Thereafter, the lifting cylinder 15 was extended to raise the coil 1 together with the coil skid 21, and the height of the center point of the inner periphery of the coil 1 was made to coincide with the axis of the coil unwinding reel 41.
On the other hand, the outer diameter of the coil unwinding reel 41 is reduced (outer diameter 570 mm), the travel drive device is driven to move the coil transport carriage 2 toward the coil unwinding reel 41, and the coil unwinding reel is placed in the hole of the coil 1. 41 was inserted.
Thereafter, the coil unwinding reel 41 is enlarged (to an outer diameter of 610 mm), the pressure of the coil opening / closing arm opening / closing cylinder 33 is released (the coil opening correcting arm opening / closing cylinder 33 is extended to release the correction load), The opposing coil deformation correction arm 31 is rotated around the coil deformation correction arm fulcrum pin 34 to open the coil deformation correction arm 31. Finally, the elevating cylinder 15 is shortened to lower the coil skid 21, the wheels 12 of the coil transport carriage 2 are driven by the travel drive device to travel on the rail 9, and the coil transport carriage is moved offline from the coil unwinding reel 41. 2 was transported to complete the work.

  In addition, the coil 1 after the correction had no wrinkles or the like due to the coil deformation correcting arm pad 32 or the like after passing through the smoothing annealing equipment.

[Example 2]
A coil 1 having a high-temperature finish of a grain-oriented electrical steel sheet having a thickness of 0.23 mm (coil inner diameter is 610 mm (converted to a perfect circle), width is 1555 mm, outer diameter (converted to a perfect circle) is 1560 mm)) The coil unwinding reel of the smoothing annealing equipment (FIG. 6) using the coil transport carriage 2 (see FIGS. 1 to 3 and 4: the radius of curvature of the arm pad 32 of the arm 31 for correcting coil deformation is 1100 mm). 41.
The shape of the inner periphery of the coil 1 was an ellipse with a long horizontal direction of 640 mm in the horizontal direction and 585 mm in the vertical direction. Actuates the coil deformation straightening arm opening and closing cylinder 33 to the pressing force 90 kN, by adding a load (corrected load) to the coil 1 via the coil deformation orthodontic Amupa' de 32 by the coil the leveling arm 31, the deformation of the coil 1 The shape of the inner periphery of the coil was corrected to a substantially perfect circle with a horizontal direction of 615 mm and a vertical direction of 605 mm.
In this state, the coil conveying carriage 2 and the lifting cylinder 15 were operated in the same manner as in Example 1 and inserted into the coil unwinding reel 41 of the smooth annealing equipment (FIG. 6).
In addition, the coil 1 after the correction had no wrinkles or the like due to the coil deformation correcting arm pad 32 or the like after passing through the smoothing annealing equipment.

1 Coil 2 Coil carrier cart 4 Civil engineering foundation (concrete foundation)
9 Rail 11 Coil carrier carriage frame 12 Wheel 13 Axle 14 Bearing 15 Lift cylinder 16 Lift cylinder trunnion 17 Lift cylinder mounting bracket 18 Lift cylinder guide rod 19 Lift cylinder guide rod guide bracket 20 Lift cylinder rod 21 Coil skid 22 Coil skid pad 31 Coil Deformation correction arm 32 Coil deformation correction arm pad 33 Coil deformation correction arm open / close cylinder 34 Coil deformation correction arm open / close cylinder fulcrum pin 41 Coil unwinding reel 42 Coil unwinding device main body 43 Coil unwinding device drive device

Claims (4)

In the coil transport carriage that is provided with a coil skid for loading the coil and is allowed to travel on the rail,
The coil is a coil of grain-oriented electrical steel sheet that is wound after being coated with an annealing separator and then subjected to high-temperature finish annealing,
In the coil carrier cart,
A coil skid lifting / lowering support mechanism for supporting the coil skid to freely move up and down;
Coil deformation correction arms provided with base ends pivotably provided on the left and right sides of the coil skid in the direction of travel of the coil transport carriage, and with tip ends facing each other so as to move toward or away from each other. When,
A correction load control means for controlling the correction load applied to the coil by the opposing coil deformation correction arm;
The correction load control means makes the coil thickness dimension, sheet width dimension and material constant.
As a variable having the outer diameter of the coil as a parameter, the correction load applied to the coil by the coil deformation correcting arm and the short diameter when the coil hole is elliptical (hereinafter referred to as the minimum diameter of the coil hole). Seeking a relationship with
A coil conveying carriage characterized in that a correction load at which the minimum diameter of the coil hole is larger than the outer diameter of the coil unwinding reel is set as the optimum correction load in the above parameters. The value of R / RO is at least 0.95, where R is the curvature radius of the cross section of the contact surface with the coil at the tip of the coil deformation correcting arm and RO is the curvature radius of the coil outer diameter. coil transport carriage according to claim 1, characterized in that. Transfer method of the coil, characterized by conveying while correcting the deformation of the coil by the coil transport carriage according to claim 1 or 2. Assuming that the coil thickness dimension, the sheet width dimension, and the material are constant and the outer diameter of the coil is a parameter, the correction load applied to the coil by the coil deformation correction arm and the coil hole are elliptical. The relationship with the short diameter (hereinafter also referred to as the minimum diameter of the coil hole)
The correction load at which the minimum diameter of the coil hole is larger than the outer diameter of the coil unwinding reel is the optimum correction load in the above parameters,
The coil conveying method according to claim 3 , wherein the coil is straightened with the optimum straightening load at the parameter.