JPH08281308A - Method for designing die for metallic plate edging device and metallic plate edging device - Google Patents

Abstract

PURPOSE: To easily design a die shape by designing the die shape so that the area of a cross section vertical to the direction of the pass line of a space formed with edging dies and press plates is constant in the direction of the pass line. CONSTITUTION: A metallic plate is reduced in the width direction with the edging dies. The metallic plate is vertically pressed with the press plates and a metallic material is edged in the width direction. When the length of the edging dies is expressed by L, the width and thickness in the initial size of the metallic plate by w0 and h0 respectively, the intervals of the respective dies on the outlet side at the time of completing edging by w1 in the edging die and h1 in the press plate, the intervals between the respective dies in a position at a distance (x) from the inlet of the dies by W in the edging die and H in the press plate, the dies are designed so as to be H=w0 .h0 /W. It is preferable to linearly change the height of the cross section of the die in the direction of the pass line. Or it is preferable to linearly change the width of the cross section of the die in the direction of the pass line. The edging die and press plate are designed according to the formula.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a die design method and a width reduction device for a metal plate width reduction device for hot-width reducing a metal plate material having a relatively large thickness such as a slab by a press with a large reduction amount.

[0002]

2. Description of the Related Art FIGS.
It is explanatory drawing of the example of the metal plate width reduction apparatus described in the 15th publication. 3 is a plan view of a main part of the width reduction device, FIG. 4 is a front sectional view of the device shown in FIG. 3, and FIG. 5 is a side view of the device shown in FIG. The width reduction device mainly includes a width reduction die 1 and a pressing plate 13.

The width reduction dies 1 are arranged substantially symmetrically so that they can move forward and backward on the left and right of the pass line 1. The widthwise distance between the opposing die surfaces 1a, 1a of the die 1 becomes narrower from the inlet EN toward the outlet EX, and a parallel portion (1b, 1a) is provided on the outlet side.
b) is provided. The width reduction die 1 is connected to a driving device (not shown) via a rod 3.

The pressing plate 13 is wider than the plate width after the width reduction and does not move in the plate width direction. The pressing plate 13 has a thickness sufficient to prevent buckling by itself,
In order to absorb the increase in the thickness of the metal plate material S due to the width reduction, the plate thickness gradually decreases in the traveling direction of the pass line as shown in FIG.

In the width reduction apparatus constructed as described above, the metal plate material S is intermittently sent along the pass line 1 by the transfer roller table (neither is shown) through the continuous casting machine and the soaking furnace. While the metal plate material S is being fed, the width reduction die 1 is left and right open. When the metal plate S stops between the width reduction dies 1,
The interval between the width reduction dies 1 is gradually narrowed, and the metal plate material S is reduced in the width direction.

At this time, the pressing plate 13 presses the metal plate material S under width reduction from above and below to prevent the metal plate material S from buckling. When the width reduction of the metal plate material S is completed, the width reduction die 1 retracts and is returned to the initial position. Then, the metal plate material S is advanced by the length of the next one width reduction step.

6, 7 and 8 are Japanese Patent Application Laid-Open Nos. 6-277714 and 6-27771 filed by the applicant earlier.
It is explanatory drawing of the 2nd example described in the 5th publication. 6 is a plan view of a main part of the width reduction device, FIG. 7 is a front sectional view of the device shown in FIG. 6, and FIG. 8 is a side view of the device shown in FIG.
The same devices and members as those in the above example are designated by the same reference numerals, and the description thereof will be omitted.

In this example, the pressing plates 5 are slidably in contact with the upper and lower surfaces of the width reduction die 1 so as to press the width-reduced portion of the metal plate material S from above and below, and form a pair. . The set of the pressing plates 5 is arranged so as to face the left and right sides of the pass line 1. Holding plate 5
Protrudes from the front edge of the width reduction die 1 toward the center of the pass line, and substantially covers the upper and lower surfaces of the metal plate material S in the state where the width reduction die 1 has advanced by the maximum stroke.

The length of the pressing plate 5 along the pass line 1 is substantially equal to the length of the width reduction die 1 along the pass line 1. Further, the pressing plate 5 can advance and retreat together with the width reduction die 1 in the width direction of the metal plate material, and the rod 7 of the drive device for moving the pressing plate 5 forward and backward is connected to the side surface of the pressing plate 5. The pressing plate 5 advances together with the width reduction die 1. The thickness of the pressing plate 5 is gradually reduced with respect to the traveling direction of the pass line so as to absorb the increase in the thickness of the metal plate material S due to the width reduction.

For each pressing plate 5, four pressing rolls 9 are rotatably attached to the housing 11. The pressing roll 9 located at the foremost end is in contact with the foremost end of the pressing plate 5 at the position advanced by the maximum stroke. The length of the pressing roll 9 is slightly longer than the width of the pressing plate 5.

In the width reduction apparatus configured as described above, the metal plate material S is intermittently sent along the pass line 1 by the transfer roller table (neither is shown) through the continuous casting machine and the soaking furnace. While the metal plate material S is being fed, the width reduction die 1 and the pressing plate 5 are left and right open. When the metal plate material S stops between the width reduction dies 1, the interval between the width reduction dies 1 is gradually narrowed,
The metal plate material S is pressed down in the width direction.

At this time, the pressing plate 5 also advances together with the width reduction die 1, and presses the metal plate material S under width reduction from above and below to prevent the metal plate material S from buckling. The pressing roll 9 supports the pressing plate 5 and prevents the pressing plate 5 from being deformed. Also,
Due to the movement of the pressing plates 5 to the center of the pass line, the distance between the pressing plates 5 becomes narrower, and even if the width of the metal plate material becomes narrower, the metal plate material S is uniformly held by the pressing plate 5, and the buckling of higher order is performed. Can be prevented. When the width reduction of the metal plate material S is completed, the width reduction die 1 and the pressing plate 5 are retracted and returned to the initial position. Then, the metal plate material S is advanced by the length of the next one width reduction step.

[0013]

However, in these devices described in JP-A-6-277714 or JP-A-6-277715, the deformation amount of the metal plate material due to the width reduction is calculated or experimentally obtained in advance. Since the die cross-sectional shape is designed, there is a problem that the design requires a large amount of cost and time.

[0014]

In order to solve the above problems, the present invention relates to a metal plate width reduction device, in which a pass line of a space formed by the left and right width reduction dies and the pressing plate at the end of width reduction. The area of the cross section perpendicular to the direction is
It is characterized in that the shape of the width reduction die and the shape of the pressing plate are designed so as to be constant in the pass line direction. That is, the gist of the present invention is as follows.

Left and right width reduction dies for reducing the plate material in the plate width direction, a die driving device for advancing and retracting the width reduction die in the plate width direction, and upper and lower pressing plates for pressing the width-reduced portion of the metal plate material from above and below. In the metal plate width reduction device for reducing the metal material in the width direction, the area of the cross section perpendicular to the pass line direction of the space formed by the left and right width reduction dies and the pressing plate at the end of the width reduction, It is a die design method for a metal plate width reduction device, characterized in that the shape of the width reduction die and the shape of the pressing plate are designed so as to be constant in the pass line direction, and the height of the die cross section is preferable. Alternatively, in the die design method, the shape of the width reduction die and the shape of the pressing plate are designed such that the width of the die cross section changes linearly in the pass line direction.

Further, left and right width reduction dies for reducing the plate material in the plate width direction, a die driving device for advancing and retracting the width reduction die in the plate width direction, and an upper and lower device for pressing the width-reduced portion of the metal plate material from above and below. In a metal plate width reduction device that includes a pressing plate, the left and right dies, and a space formed by the upper and lower pressing plates to reduce a metal material in the width direction, the left and right width reduction dies at the end of the width reduction. An area of a cross section perpendicular to the pass line direction of the space formed by the pressing plate is a metal plate width reduction device characterized by being constant in the pass line direction, preferably the height of the die cross section or the die. It is a metal plate width reduction device characterized in that the width of the cross section changes linearly in the pass line direction.

[0017]

The present invention will be described in detail below with reference to the drawings. FIG. 3 shows an example of a metal plate width reduction device for carrying out the method of the present invention. FIG. 3 is a plan view of the main part of the width reduction device, FIG.
3 is a front sectional view of the device shown in FIG. 3, and FIG. 5 is a side view of the device shown in FIG. The width reduction device mainly includes a width reduction die 1 and a pressing plate 13.

The width reduction dies 1 are arranged substantially symmetrically so that they can move forward and backward on the left and right of the pass line 1. The widthwise distance between the opposing die surfaces 1a, 1a of the die 1 narrows from the inlet EN toward the outlet EX, and the parallel portions 1b, 1b are provided on the outlet side.
Is provided. The width reduction die 1 is connected to a driving device (not shown) via a rod 3.

The pressing plate 13 is wider than the plate width after the width reduction and does not move in the plate width direction. The pressing plate 13 has a thickness sufficient to prevent buckling by itself,
In order to absorb the increase in the thickness of the metal plate material S due to the width reduction, the plate thickness gradually decreases in the traveling direction of the pass line as shown in FIG.

In the width reduction device constructed as described above, the metal plate material S is intermittently sent along the pass line 1 by the transfer roller table (neither is shown) through the continuous casting machine and the soaking furnace. While the metal plate material S is being fed, the width reduction die 1 is left and right open. When the metal plate S stops between the width reduction dies 1,
The interval between the width reduction dies 1 is gradually narrowed, and the metal plate material S is reduced in the width direction.

At this time, the pressing plate 13 presses the metal plate material S under width reduction from above and below to prevent the metal plate material S from buckling. When the width reduction of the metal plate material S is completed, the width reduction die 1 retracts and is returned to the initial position. Then, the metal plate material S is advanced by the length of the next one width reduction step.

Here, the symbols relating to the dimensions of the die cross section, the metal plate material, the width reduction die and the pressing plate are defined as shown in Table 1. As shown in FIG. 3, x represents the distance along the pass line 1 from the entrance EN of the width reduction die in the exit EX direction. At this time, an arbitrary position x (0 <x <in the pass line direction in the state (FIG. 3) at the end of the reduction in the width direction.
L) a cross section of a space formed by the upper and lower pressing plates and the left and right width reduction dies (hereinafter, referred to as a die cross section)
The area A of A is expressed by A = WH ... (1) (Fig. 4).

[0023]

[Table 1]

Further, with respect to the position x in the pass line direction,
The difference between the width D _w0 of the width reduction die at x = 0 and the width D _wx of the width reduction die at x = x, that is, the width increase amount of the width reduction die is ΔW _s (FIG. 3). Further, the difference between the thickness P _h0 of the holding plate at x = 0 and the thickness P _hx of the holding plate at x = x, that is, the amount of decrease in the thickness of the holding plate is ΔHv (FIG. 5).

The state at the end of width reduction means a state in which the dice on the left and right sides are fully extended (state at maximum width reduction). That is, it means the state at the time when the area of the die cross section becomes the minimum.

As a result of the ingenuity, the inventors of the present invention have shown in the following that, if the die cross-sectional area A is always constant for any x in the range of 0≤x≤L, the metal is preliminarily subjected to width reduction. It was found that the shape of the die and the pressure plate without buckling can be designed without calculating the deformation amount of the plate material by calculation or experiment.

That is, in order to smoothly reduce the width of the metal plate material, first, as shown in the equation (2), at x = 0, the width W ₀ of the die section and the thickness H ₀ of the die section are set. It is necessary to make it equal to the initial dimensions (plate width w ₀ , plate thickness h ₀ ). That is, W ₀ = w ₀ , H ₀ = h ₀ (2) Further, since it is considered that there is no deformation in the longitudinal direction of the metal plate material during width reduction, any position in 0 ≦ x ≦ L is satisfied. At x, the following is always established: w · h = w ₀ · h ₀ .

Therefore, the area of the die cross section also corresponds to the shape of the metal plate material, and when 0 ≦ x ≦ L, A = W · H = W ₀ · H ₀ = w ₀ · h ₀ (3) It should be designed as follows. Further, since the width W ₁ of the die cross section at x = L needs to be equal to the plate width w ₁ of the metal plate material after the width reduction, W ₁ = w ₁ (4)

Therefore, from the equation (3), the height H ₁ of the die section at x = L is

[Equation 1] It is necessary to That is, the area A of the die cross section at the end of the width reduction is constant in the pass line direction (W ₀ · H ₀ = W
The width and thickness of the width reduction die forming the die cross section, the width of the pressing plate, and the thickness are determined so that H = W ₁ · H ₁ ).

Based on the above concept, the plate width w ₀ ,
In order to reduce the width of the metal plate material having the plate thickness h ₀ to the plate width w ₁ , the width reduction die is designed as follows. Plate thickness Inlet plate thickness (x = 0): D _h0 = H ₀ Plate thickness at any position (0 <X <L): D _hx = H Outlet plate thickness (x = L): D _h1 = H ₁ ......... (5-1) the plate width inlet of the plate width (x = 0): D _w0 is the strength sufficient strip width. Plate width at arbitrary position (0 <X <L): D _wx = D _w0 + ΔW _s Here, ΔW _s = (W ₀ −W) / 2 ………… (5-2) Plate width of outlet (x = L): D _w1 = D _w0 + (W ₀ −W ₁ ) / 2 Length: At least L or more. If necessary, a parallel portion may be added as shown in FIG. 3 in order to improve the surface quality of the plate end portion. L is determined in consideration of the deformation strength of the metal material to be rolled down, the rolling force of the rolling down device, etc.
When the rolling force is small, it is desirable to increase L.

Further, the pressing plate may be designed as follows. Plate Thickness Plate thickness at the inlet (x = 0): P _h0 is a plate thickness sufficient for strength. Plate thickness at arbitrary position (0 <X <L): P _hx = P _h0 −ΔH _V where ΔH _V = (H ₁ −H) / 2 ………… (5-3) Plate thickness at the outlet _{(x = L): P h1} = P h0 - (H 1 -H) / 2 the thickness of the width inlet (x = 0): P _w0 is the width greater than the metal plate. Plate thickness at any position (0 <X <L): P _wx is wider than the metal plate material. The plate thickness (x = L) of the outlet part: P _w1 is wider than the metal plate material. In general, it is efficient to set P _w0 = P _wx = P _w1 . Length: At least L or more. The width may be increased according to the length of the die.

As can be seen from FIG. 5, the plate thickness difference D _{h0 to} D _hx of the width reduction die is equal to the plate thickness difference P _{h0 to} P _hx of the pressing plate. Although the above description is based on the mechanism shown in FIG. 3, the same applies to the mechanism shown in FIG. Furthermore, as shown in FIG. 9, when the width reduction is started in the middle of the width reduction die, the position where the die and the metal plate material start to contact each other may be set to x = 0 for designing.

A design example of the width reduction die 1 and the pressing plate 5 based on the equations (3) and (5) will be described below. First
As an example of FIG. 1, the shape of the die cross section when the height H of the die cross section linearly changes in the pass line direction (0 ≦ x
≦ L) is shown. The shape when L ≦ x is the same as that in FIG. H
Since the change of is linear, H for 0 ≦ x ≦ L is calculated by using H ₁ of the equation (5),

[Equation 2] It is represented by.

Since the die cross-sectional area A is always constant, from equation (3)

(Equation 3) Becomes Substituting equation (6) into (7),

[Equation 4] Is found. Therefore, equations (5-1), (5-2),
Based on (5-3), the width reduction die and the pressing plate may be designed as follows.

[Width Reduction Die] Plate Thickness Plate Thickness at Inlet (x = 0): D _h0 = H ₀ Plate Thickness at Arbitrary Position (0 <X <L): D _hx = H Plate Thickness at Exit (x = L): D _h1 = H ₁ plate width The plate width at the inlet (x = 0): D _w0 is a plate width sufficient for strength. Arbitrary Position Plate Width (0 <X <L): D _wx = D _w0 + ΔW _s Plate Width at Exit (x = L): D _w1 = D _w0 + (W ₀ −W
₁ ) / 2 Length: At least L or more, and a parallel part may be added if necessary.

[Pressing Plate] Plate Thickness Plate Thickness at Inlet (x = 0): P _h0 is a plate thickness sufficient for strength. Plate thickness at arbitrary position (0 <X <L): P _hx = P _h0 -ΔH _V Plate thickness at outlet (x = L): P _h1 = P _h0- (H ₁ -H
₀ ) / 2 width Plate thickness at entrance (x = 0): P _w0 is wider than the metal plate material. Arbitrary position plate thickness (0 <X <L): P _wx is wider than the metal plate material. The plate thickness (x = L) of the outlet part: P _w1 is wider than the metal plate material. Length: L or more. The width may be increased according to the length of the die.

As a second example, the width W of the die section is shown in FIG.
Shows the shape (0 ≦ x ≦ L) of the cross section of the die when is linearly changed in the pass line direction. The shape when L ≦ x is the same as that in FIG. Since the change of W is linear, 0 ≦ x ≦ L
W in

(Equation 5) It is represented by.

Since the die cross-sectional area A is always constant, from equation (3),

(Equation 6) Becomes Substituting equation (9) into equation (10),

(Equation 7) Is found. Of course, the equation (11) satisfies the equation (5) when x = L. Therefore, equation (5-1),
Based on (5-2) and (5-3), the width reduction die and the pressing plate may be designed as follows.

[Width Reduction Die] Plate Thickness Plate Thickness at Entrance (x = 0): D _h0 = H ₀ Plate Thickness at Arbitrary Position (0 <X <L): D _hx = H Plate Thickness at Exit (x = L): D _h1 = H ₁ plate width The plate width at the inlet (x = 0): D _w0 is a plate width sufficient for strength. Arbitrary Position Plate Width (0 <X <L): D _wx = D _w0 + ΔW _s Plate Width at Exit (x = L): D _w1 = D _w0 + (W ₀ −W
₁ ) / 2 Length: At least L or more, and a parallel part may be added if necessary.

[Pressing Plate] Plate Thickness Plate Thickness at Inlet (x = 0): P _h0 is a plate thickness sufficient for strength. Plate thickness at arbitrary position (0 <X <L): P _hx = P _h0 -ΔH _V Plate thickness at outlet (x = L): P _h1 = P _h0- (H ₁ -H
₀ ) / 2 width Plate thickness at entrance (x = 0): P _w0 is wider than the metal plate material. Arbitrary position plate thickness (0 <X <L): P _wx is wider than the metal plate material. The plate thickness (x = L) of the outlet part: P _w1 is wider than the metal plate material. Length shall be L or more. The width may be increased according to the length of the die.

In the above two examples, one of the thickness and the width is changed linearly, but it goes without saying that both the thickness and the width may be changed by a curved line. FIG. 10 is a block diagram summarizing the above and showing the design procedure of the shapes of the width reduction die and the pressing plate.
Shown in Table 2 shows the design details of the width reduction die shape and the pressing plate shape.

[0042]

[Table 2]

[0043]

【Example】

(Example 1) Based on the equations (6) and (8) (when the change in the thickness H of the die section is a straight line), the plate width w ₀ = 1500
In order to reduce the width of a slab having a thickness of mm and a thickness of h ₀ = 30 mm to a width of w ₁ = 968 mm, a width reduction die and a pressing plate having the dimensions shown in Table 3 were designed (FIG. 1). When the width reduction of the slab was performed using the width reduction die and the pressing plate, the width could be reduced to a predetermined plate width and buckling did not occur.

[0044]

[Table 3]

[Width reduction die] (unit: mm) Plate thickness Plate thickness at entrance (x = 0): D _h0 = H ₀ = 30 Plate thickness at arbitrary position (0 <X <L): D _hx = H = 0.0126
9x + 30 Plate thickness at outlet (x = L): D _h1 = H ₁ = 46.5 Plate width Plate width at inlet (x = 0): D _w0 = 600 Plate width at arbitrary position (0 <X <L): D _wx = D _w0 + ΔW _s = 6
00 + ΔW _s Here, ΔW _s = 750− (5.85 × 10 ⁷ ) / (33x + 78)
000) Plate width of outlet (x = L): D _w1 = D _w0 + (W ₀ −W
₁ ) / 2 = 866 Length: 1500

[Pressing Plate] (Unit: mm) Plate Thickness Plate Thickness at Entrance (x = 0): P _h0 = 208.25 Plate Thickness at Any Position (0 <X <L): P _hx = P _h0 −ΔH _V = 2
08.25−ΔH _V where ΔH _V = 8.25−0.006345x Plate thickness at exit (x = L): P _h1 = P _h0 − (H ₁ −H
₀ ) / 2 = 200 width: P _w0 = P _wx = P _w1 = 3
300 Length: 1500

(Embodiment 2) Based on the equations (9) and (11) (when the change in the width W of the die section is a straight line), the plate width w
₀ = 1500mm, thickness h ₀ = 30mm of the slab the plate width w ₁
In order to reduce the width to 968 mm, a width reduction die and a pressing plate having the dimensions shown in Table 4 were designed (Fig. 2). When the width reduction of the slab was performed using the width reduction die and the pressing plate, the width could be reduced to a predetermined plate width and buckling did not occur.

[0048]

[Table 4]

[Width Reduction Die] (Unit: mm) Plate Thickness Plate Thickness at Inlet (x = 0): D _h0 = H ₀ = 30 Plate Thickness at Any Position (0 <X <L): D _hx = H = 5.85 x 1
0 ⁷ /(-532x+1.95×10 ⁶ ) Plate thickness at outlet (x = L): D _h1 = H ₁ = 46.5 Plate width Plate width at inlet (x = 0): D _w0 = 600 Arbitrary Position plate width (0 <X <L): D _wx = D _w0 + ΔW _s = 6
00 + 0.2046x Plate width at outlet (x = L): D _w1 = D _w0 + (W ₀ −W
₁ ) / 2 = 866 Length: 1500

[Pressing Plate] (Unit: mm) Plate Thickness Plate Thickness at Entrance (x = 0): P _h0 = 208.25 Plate Thickness at Any Position (0 <X <L): P _hx = P _h0 −ΔH _V = 2
08.25−ΔH _V Here, ΔH _V = 23.25 + 5.85 × 10 ⁷ / (1
Thickness of 064x-3.9 × 10 ⁶⁾ outlet _{(x = L): P h1} = P h0 - (H 1 -H
₀ ) / 2 = 200 width: P _w0 = P _wx = P _w1 = 3
300 Length: 1500

[0051]

According to the present invention, it is possible to easily design the shapes of the width reduction die and the pressing plate that do not cause buckling in the plate width reduction device.

[Brief description of drawings]

FIG. 1A is a plan view showing a cross section of a first example of a die formed by a width reduction die and a pressing plate in a plate width reduction device of the present invention, and FIG. 1B is a side view of FIG. Is.

2A is a plan view showing a cross section of a second example of a die formed by a width reduction die and a pressing plate in a plate width reduction device of the present invention, and FIG. 2B is a side view of FIG. Is.

FIG. 3 is a main part plan view showing an example of the configuration of a width reduction device.

FIG. 4 is a front sectional view of a main part of the width reduction device shown in FIG.

5 is a side view of a main part of the width reduction device shown in FIG.

FIG. 6 is a plan view of a main part showing another example of the configuration of the width reduction device.

7 is a front sectional view of a main part of the width reduction device shown in FIG.

FIG. 8 is a side view of a main part of the width reduction device shown in FIG.

FIG. 9 is an explanatory diagram showing the definition of x in the case where the width reduction is started in the middle of the width reduction die in the plate width reduction device of the present invention.

FIG. 10 is a block diagram showing a procedure for designing the shapes of a width reduction die and a pressing plate.

[Explanation of symbols]

 1 Width reduction die 3 Rod of driving device 5 Holding plate 7 Rod of driving device 9 Holding roll 11 Housing 13 Holding plate l Pass line

Claims (6)

[Claims] 1. A left and right width reduction die for reducing a plate material in the plate width direction, a die driving device for advancing and retracting the width reduction die in the plate width direction, and an upper and lower device for pressing the width-reduced portion of the metal plate material from above and below. In a metal plate width reduction device for reducing a metal material in the width direction with a pressing plate, a cross section perpendicular to the pass line direction of the space formed by the left and right width reduction dies and the pressing plate at the end of the width reduction. A die design method for a metal plate width reduction apparatus, characterized in that the shape of the width reduction die and the shape of the pressing plate are designed so that the area becomes constant in the pass line direction. 2. The die designing method according to claim 1, wherein the shape of the width reduction die and the shape of the pressing plate are designed such that the height of the die cross section changes linearly in the pass line direction. . 3. The die designing method according to claim 1, wherein the shape of the width reduction die and the shape of the pressing plate are designed such that the width of the die cross section changes linearly in the pass line direction. 4. A left and right width reduction dies for reducing the plate material in the plate width direction, a die driving device for advancing and retracting the width reduction die in the plate width direction, and an upper and lower device for pressing the width-reduced portion of the metal plate material from above and below. In a metal plate width reduction device that includes a pressing plate, and presses down a metal material in a width direction by a space formed by the left and right dies and the upper and lower pressing plates,
A metal plate width reduction device, wherein an area of a cross section of a space formed by the left and right width reduction dies and the pressing plate at the end of the width reduction is perpendicular to the pass line direction. 5. The metal plate width reduction apparatus according to claim 4, wherein the height of the die cross section linearly changes in the pass line direction. 6. The metal plate width reduction apparatus according to claim 4, wherein the width of the die section changes linearly in the pass line direction.