JP2957807B2 - Mandrel for down coiler - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mandrel for a down coiler (winding machine) suitable for use in hot rolling.

[0002]

2. Description of the Related Art FIGS. 1A and 1B show a conventional mandrel structure in a horizontal section and a vertical section. In the drawing, reference numeral 1 denotes a segment forming a cylindrical body, and 2 denotes a wedge shaft which expands and contracts the segment 1 as it moves in the axial direction. In this example, the wedge shaft has five rows of inclined surfaces (wedges) 2a. . Reference numeral 3 denotes a mandrel for holding the segment 1 and the wedge shaft 2, and reference numeral 4 denotes a push rod for controlling the axial movement of the segment 1. Here, the segment 1 forming the cylindrical body is required to be a perfect circle particularly in the entire region extending in the trunk length direction in the expanded state. In the above structure,
In order to form a perfect circle, both ends of the segment 1 are restrained from the outer periphery by the rings 5 at both ends, and the wedge shaft 2 is pulled in an expanded state, thereby maintaining the roundness.

However, the inclined surface 1a of the segment 1
And the inclined surface 2a of the wedge shaft 2 constantly slides and expands and contracts repeatedly. Especially, the wedge surface in the central portion in the body length direction is easily worn, so that the outer periphery of the segment 1 is deformed concavely in the body length direction. Would. Segment 1 is internally cooled by cooling water 6,
Due to the repetition of heating and cooling, the segment 1 itself is also deformed into a concave shape in the body length direction, and even in the expanded state, the outer periphery of the segment becomes wrapped, making it difficult to maintain a perfect circle in the body length direction. Conventionally, as a countermeasure against such a problem, as described in JP-A-61-269934, only a wear-resistant layer is formed on a sliding portion.

[0004]

As described above, due to the wear of the central portion of the wedge surface in the body length direction and the wear of the inner diameter portion of both end rings and the outer diameter portions of both ends of the segment, the segment becomes concave in the body length direction. Easy to be. Also, the surface of the segment itself is exposed to high temperatures, while the inside of the mandrel is cooled from the inside to the inside. Therefore, since the outer periphery of the mandrel segment has a hump-like shape, there is a disadvantage that the tension of the strip edge is increased particularly when winding a thin material, and the shape is greatly impaired. The present invention advantageously solves the above-mentioned problem, and proposes a mandrel that can always maintain a perfect circle (body length direction) even when the above-described wear occurs or a heat distortion occurs in a segment. The purpose is to:

[0005]

That is, the present invention provides:
A wedge shaft capable of moving in the axial direction and having a plurality of rows of inclined surfaces, a circumferentially divided segment surrounding the wedge shaft in a cylindrical shape, and restraining the outer periphery of the segment at both ends. In a mandrel for a down coiler having a ring and having a function of radially displacing a segment by a sliding action between an inclined surface of a wedge shaft and a segment inclined surface, a segment inner peripheral surface and a wedge shaft are used as means for expanding and displacing a segment by elastic force. With respect to the segment, a displacement corresponding to δ in the following equation

(Equation 2) A mandrel for a down coiler, wherein a spring having a spring reaction force W for providing the following is provided.

[0006]

[0007]

FIGS. 2 (a) and 2 (b) show a preferred embodiment of a mandrel according to the present invention in a transverse section and a longitudinal section. The outline of the configuration is the same as that of FIG. 1 described above, and thus the same reference numerals are given. In the figure, reference numeral 7 denotes a spring case containing a spring (in this example, a disc spring), and 8 denotes a slide rod.
According to the present invention, in order to always keep the segment body length direction in a perfect circle, a slide rod 8 is arranged between the segment 1 and the wedge shaft 2, and a spring having a reaction force capable of further elastically deforming the segment 1. The case 7 is disposed, and the segments 1 are always pressed outward by applying a spring reaction force in a state where both ends of the segments 1 are restrained from the outside by the rings 5. Necessary reaction force of the spring here is a necessary spring force can provide a total clearance [delta] corresponding elastic deformation of the wear amount [delta] ₂ of the mechanical clearance [delta] ₁ and the wedge surface segment.

[0009]

[Action] usually occurs slight thermal distortion clearance [delta] ₁ is provided between the slide rod and the segment in order to perform the scaling of the mandrel smoothly, but the wear amount of the wedge surface in the gap [delta] ₁ [delta] _If a displacement corresponding to the total amount δ obtained by adding ₂ is given to the segment from the inside, the segment can always be kept in a perfect circle in the body length direction. That is

(Equation 3) By setting the reaction force W of the spring in such a manner, it is possible to always provide a perfectly circular mandrel.

Usually, the gap δ is about 1 mm, the Young's modulus E of the segment is 2.1 × 10 ⁴ kg / mm ² , and the second moment of area I obtained from the segment shape is 5.1 × 10 ⁷
mm, and the segment body length l is 1920 mm,

(Equation 4) Therefore, ΣW = 12,500 kg is obtained. Therefore, if springs are distributed in 5 places, the reaction force per piece is 250.
A spring force of 0 kg is sufficient. In other words, by constantly pressing with a spring at 12,500 kg, the segment is given an elastic strain equivalent to δ, so that even if a thermal strain occurs in the segment, it can be made a perfect circle in the body length direction.

[0011]

FIG. 3 shows a preferred embodiment of a mandrel according to the present invention in a partially cutaway perspective view. As shown in the figure, a slide rod 8 and a disc spring case unit 7 are provided between the segment 1 and the wedge shaft 2. Here, the disc spring case unit 7 always presses the segment 1 in a direction to enlarge. In the mandrel structure described above, when the wedge shaft 2 moves in the direction of the arrow, the segment 1 enters the "spread" state. That is, while the disc spring case unit 7 and the slide rod 8 are restrained from moving in the axial direction by the mandrel member 9,
Since the wedge shaft 2 is free to move in the axial direction, when the wedge shaft 2 is moved in the direction of the arrow,
The disc spring case unit 7 and the slide rod 8 are pushed up by the inclined surface 2a of the edge shaft 2, and as a result, the segment 1 expands to the outer peripheral side.

Here, the disc spring case unit is not merely provided at both ends and the center as a simple play, but has a reaction force capable of giving a sufficient displacement δ for elastically deforming the segment in the outer peripheral direction. is necessary. Although it depends on the body length l, it is usually preferable to provide three or more.

The amount of displacement by the spring is determined by the mechanical clearance δ
It is necessary to consider the total amount of wear [delta] _{2 1} and the sliding portion, but set to the normal 1 to 1.5 mm by around. The mandrel constructed as described above always has a perfect circular shape because the segments are always elastically deformed outward by the spring reaction force even if the segments are warped or distorted in an amount corresponding to the wear of the internal sliding portion or the gap. It can provide a perfect outer circumference.

[0014]

As described above, according to the present invention, the outer periphery of the segment is always kept in a perfect circle over the entire length of the body even if the segment is thermally strained or the wedge sliding portion is worn. Can be. Therefore, in the past, when heat distortion or wedge wear occurred in the segment, the segment and the wedge shaft had to be discarded, but according to the present invention, the life of these can be extended. In addition, since no wrapping deformation occurs at the time of winding, there is no downgrade due to deterioration of the shape at the time of winding, which greatly contributes to quality improvement.

[Brief description of the drawings]

FIG. 1 is a view showing a conventional mandrel structure.

FIG. 2 is a view showing a mandrel structure according to the present invention.

FIG. 3 is a partially cutaway perspective view of a preferred mandrel according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 segment 1a Segment inclined surface 2 Wedge shaft 2a Wedge shaft inclined surface 3 Core axis 4 Push rod 5 Ring 6 Cooling water 7 Spring case 8 Slide rod 9 Mandrel member

Claims (1)

(57) [Claims] 1. A wedge shaft capable of moving in the axial direction and having a plurality of rows of inclined surfaces, a circumferentially multi-segmented segment surrounding the wedge shaft in a cylindrical shape, and an outer periphery of the segment. and a ring for constraining at both ends, the inclined surfaces of the wedge shaft and segment
A mandrel for a down coiler having a function of displacing a segment in a radial direction by a sliding action on a segment inclined surface , wherein the segment is disposed between an inner peripheral surface of the segment and a wedge shaft as means for expanding and displacing the segment by an elastic force.
, The displacement corresponding to δ in the following equation : A mandrel for a down coiler , wherein a spring having a spring reaction force W for providing a force is provided .