JP2000271667A - Production of flash door - Google Patents

Abstract

PROBLEM TO BE SOLVED: To finish the inner face of an opening window to a beautiful external appearance by reducing a corner radius of the opening window and effectively prevent a fracture part of a corner part from extending near a surface. SOLUTION: A production method of a flash door consists of a process to open a rectangular opening window 2 to a surface panel 1, a process to open a through hole 6 at a state that a corner cut edge 8 is connect to the corner part 12 of the opening window 2, a press process to arrange a flange margin 3 by pressing the surface panel 1 along the opening window 2 and a process to fix the surface panel 1 to a door fame. A turret punch press machine 13 is used for the press process. Further, the press process consists of a first process to press the intermediate part of a long side straight part 2A of the window 2 while shifting a position at a pitch of 1-20 mm, a second process to press a short side straight part 2B and the corner part 12 having the through hole 6 and a straightening process to straighten the strain of the flange margin 3 bent inward.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a flash door provided with an opening window such as a lighting window.

[0002]

2. Description of the Related Art A flash door provided with an opening window such as a daylighting window has a front panel bent inward along the opening window to provide a clean and beautiful appearance. In a flash door having this structure, an opening window is opened in a front panel made of a metal plate, and a flange margin is provided by being bent inward along the opening window. FIG.
Shows a front panel 1 provided with a flange margin 3 along an opening window 2. After opening the opening window 2, the front panel 1 is subjected to press working, and the periphery of the opening window 2 is bent inward to provide a flange margin 3. As shown in the enlarged view of FIG. 1, the flange margin 3 formed by pressing is broken at the corner. The breaks approach the corners near the bend line 7 and degrade the appearance of the flash door.

In order to prevent this problem, as shown in FIG. 2, a technique has been developed in which a notch 4 having a rounded tip is provided at a corner of a flange allowance 3 at a corner thereof to perform press working (Japanese Patent Publication No. Hei 5-5-2). No. 43037). According to the method described in this publication, when the peripheral edge of the opening window 2 is pressed and bent inward, the notch 4
This prevents the corners from breaking.

[0004]

However, the notch 4 shown in FIG. 2 cannot effectively prevent the corner portion from breaking when the periphery of the opening window 2 is cut inward. In particular, if the corner radius is reduced, the break of the corner cannot be prevented, and the break is extended to near the bend line of the corner, that is, near the surface of the front panel, which has a bad effect on the appearance of the flash door. . To hide the break, fix a decorative frame inside the opening window,
Alternatively, it is necessary to apply putty or the like here to finish the surface. The flash door of this structure has a drawback that it takes a lot of time to manufacture and that the inner surface of the opening window cannot be finished in a clean and beautiful appearance.

[0005] The present invention has been developed for the purpose of further solving this drawback. An important object of the present invention is to provide a method of manufacturing a flash door which can reduce a corner radius of an opening window and effectively prevent a broken portion of a corner portion from being extended to near a surface.

[0006]

SUMMARY OF THE INVENTION A method of manufacturing a flash door according to the present invention includes an opening step of opening a rectangular opening window 2 in a metal surface panel 1 and a corner portion 12 of the opening window 2, wherein A step of opening the through hole 6 in a state where the cut edge 8 of the corner is connected to the part which becomes the margin 3 and pressing the front panel 1 along the opening window 2 so that the corner radius is 20 mm or less. And a step of fixing the front panel 1 provided with the flange allowance 3 to the door frame by bending inward to provide the flange allowance 3.

Further, in the method of manufacturing a flash door according to the present invention, the flange margin is bent using the turret punch press machine 13 in the pressing step. The pressing step includes a rectangular opening window 2 opened in the front panel 1.
The first pressing step of pressing the middle of the long side side linear portion 2A while shifting the position at a pitch of 1 to 20 mm to bend the flange margin 3 inward, and the short side side linear portion 2B and the through hole 6 A second pressing step of pressing the provided corner portion 12 to bend the flange margin 3 inward, and a straightening step of correcting the distortion of the flange margin 3 of the long side straight portion 2A bent inward. Consists of

[0008]

Embodiments of the present invention will be described below with reference to the drawings. However, the embodiments described below exemplify a method of manufacturing a flash door for embodying the technical idea of the present invention, and the present invention does not specify a method of manufacturing a flash door as follows.

Further, in this specification, in order to make it easy to understand the claims, the numbers corresponding to the members shown in the embodiments will be referred to as “claims” and “ In the column of “means”. However, the members described in the claims are not limited to the members of the embodiments.

[0010] The method of manufacturing a flash door of the present invention makes the process of processing the front panel a unique method. The process of assembling the textured face panel can be the same as, or will be developed from, current flash doors.

The flash door shown in FIG. 3 has an opening window 2 in a front panel 1 on both sides. The opening window 2 is a lighting window to which the glass plate 5 is fixed. Front panel 1
Are flush doors with the periphery fixed to both sides of a door frame (not shown). The front panel 1 is formed by bonding a surface sheet such as vinyl chloride to a surface of a metal plate such as iron. The front panel 1 is generally made of a steel sheet with a surface sheet made of vinyl chloride adhered thereto. The front panel 1 has, for example, a thickness of 0.5 to 1 m.
m is used. The front panel 1 has an opening window 2 opened in a state where the top sheet is adhered, and a flange margin 3 is provided by pressing.

Front panel 1 fixed to both sides of door frame
Has an opening window 2 opened at the same position opposite thereto, and a glass plate 5 is fixed here. As shown in the cross-sectional view of FIG. 4, the front panel 1 bends the flange margin 3 toward the surface of the glass plate 5, in other words, covers the inner surface of the opening window 2 with the flange margin 3. The front panel 1 has an opening window 2
Is bent inward to provide a flange margin 3. The opening window 2 of the front panel 1 has a corner radius of 20 mm or less, preferably 10 mm or less. The reason why the corner radius of the opening window 2 is reduced is to finish the corner portion in a neat shape. However, the opening window does not need to have all corner radii of 20 mm or 10 mm or less.

When the front panel 1 having a small corner radius is press-worked to provide the flange margin 3, a break is formed at the corner. In the manufacturing method of the present invention, the front panel 1 is processed in the following steps in order to effectively prevent the corner portion from being broken.

Opening Step of Opening Opening Window The front panel 1 is cut to open the opening window 2. The opening window 2 is opened by cutting the front panel 1 with a laser or pressing with a mold. The surface panel 1 provided with the opening window 2 has a surface sheet adhered to the surface. Open window 2
, The corner radius of the four corners is about 5 mm. However, the corner radius may be 3 to 20 mm, preferably 3 to 10 mm.

Step of Opening Through Holes at Corners of Flange Allowance of Front Panel As shown in FIG. 5, through holes 6 are opened at corner portions 12 which are bent inward to become flange allowances 3. The through-hole 6 is opened by pressing or cutting with a laser. The through hole 6 is opened so as to connect the cut edges 8 of the corner portions 12. That is, it is not communicated with the cutting edge 8 like the notch 4 provided in the conventional corner portion shown in FIG. 5 is opened in a crescent shape. The through-hole 6 may have a circular shape shown in FIG. 6 or an elliptical shape shown in FIG. The crescent-shaped or elliptical through-hole 6 is opened in an elongated shape along the bending line 7 as shown in the figure.

The through hole 6 has an inner width (W) up to the bending line 7.
Outer width of opening window 2 to cutting edge 8 with respect to 1) (W2)
, That is, W2 / W1 is set to be 0.5 to 4, more preferably 0.8 to 3, and still more preferably 1 to 2. If the outer width (W2) is made wider, the tensile stress inside the through hole 6 becomes stronger during press working,
Breakage inside the through hole 6 can be more effectively prevented.
However, in order to increase the outer width (W2), it is necessary to bring the through hole 6 closer to the bending line 7. Through hole 6 is bent line 7
, The inner width (W1) decreases. Inside width (W
In the narrow surface panel 1 of 1), the through-holes 6 are easily visible from the outside. The through holes 6 are preferably difficult to see from the surface of the front panel 1 if possible. In order to make the through hole 6 difficult to see, the inner width (W1) may be increased. However, when the inner width (W1) is increased, the outer width (W2) is reduced, and the corner portion is easily broken. For this reason, the inner width (W
1) and the outer width (W2) are determined in the above-mentioned range in consideration of both the broken portion and the appearance.

The inner diameter of the through hole 6, particularly the inner diameter (d) in the direction along the bending line 7, is larger than 1/2 of the corner radius and smaller than 2 times. Increasing the inner diameter (d) can more effectively prevent the corner portion from breaking. However, if the inner diameter (d) is too large, a large gap is formed in the corner portion 12 of the bent flange margin 3 to deteriorate the appearance. The ideal inner diameter (d) of the through hole 6 is substantially equal to the corner radius. However, the inner diameter (d) of the through hole 6 can be set in the above range in consideration of the appearance and the degree of breakage.

Pressing Step of Front Panel For pressing, a die 9 shown in a sectional view of FIG. 8 is used. The mold 9 includes an upper mold 9B having a concave portion 9b at the position of the opening window 2 and a lower mold 9A having a convex portion 9a at the position of the opening window 2. The concave portion 9b of the upper die 9B and the convex portion 9 of the lower die 9A
“a” is provided with a gap between the flange margin 3 of the front panel 1 and an inwardly bent portion. In the mold 9, the front panel 1 is placed on the lower mold 9A and fixed at a fixed position, the upper mold 9B is lowered, and the opening window 2 of the front panel 1 is bent inward to form the flange allowance 3. I do.

Further, a turret punch press is used as a press for performing press working using the mold having the above structure. As shown in a schematic sectional view of FIG. 9, the turret punch press 13 holds the upper turret 14 for setting the upper die 9B, the lower turret 15 for setting the lower die 9A, and the front panel 1 in a horizontal posture. A table 16 and transfer means 17 for transferring the front panel 1 at a predetermined pitch are provided. The turret punch press 13 presses the front panel 1 while holding the front panel 1 between the upper turret 14 and the lower turret 15, and presses the front panel 1 into a predetermined shape using the upper die 9B and the lower die 9A. The front panel 1 supplied to the upper surface of the table 16 is clamped and held at its edge by the clamp 18 of the transfer means 17, and is transferred at a predetermined pitch in a horizontal posture.

[First Pressing Step] As shown in FIG.
The middle of the long side linear portion 2A of the rectangular opening window 2 opened in the front panel 1 is divided into a plurality of regions and pressed while shifting the position at a predetermined pitch. Front panel 1
The edge of the transfer means 1 is clamped and held by the clamp 18.
At 7, it is transported in a direction parallel to the long side linear portion 2 </ b> A of the opening window 2. If the transfer pitch of the front panel 1 is too small, the number of times of pressing increases, and the time required for molding increases. Conversely, to increase the transfer pitch, a large die is required, and the equipment cost increases. Therefore, the transfer pitch of the front panel is set to an optimum value in consideration of the number of presses and the size of the mold. The transfer pitch of the front panel 1 is about 5 mm. However, the transfer pitch of the front panel 1 can be 1 to 20 mm, preferably 3 to 10 mm, and optimally 4 to 6 mm.

For example, as shown by arrows in FIG. 10, the front panel 1 is stamped from the vicinity of the right end corner 12 to the vicinity of the left end corner 12 while shifting the position at a predetermined pitch. However, the present invention does not specify the order in which the long side straight portion 2A of the opening window 2 is divided and pressed. The front panel can also press the long side linear portion of the opening window from the center to the end while shifting the position at a predetermined pitch.

FIG. 11 shows the mold 9 used in the first pressing step.
And a perspective view of FIG. FIG. 11 shows the lower mold 9A and FIG.
Indicates an upper mold 9B. As shown in FIG. 11, the lower mold 9A has a protrusion 9a at the center of the upper surface. However, in this figure, in order to make the shape of the protrusion 9a easy to understand, the protrusion 9
"a" has shown the state which protruded. Normally, as shown in FIG. 8, the lower mold 9A is in a state where the upper and lower bases 19 outside the convex portion 9a are pushed out by the elastic body 20 to be in the raised position, and the convex portion 9a does not protrude. The protrusion 9a of the lower mold 9A is
Is lowered and pressed, the upper and lower bases 19 descend and protrude.

The width of the central portion of the projection 9a of the lower mold 9A shown in FIG. 11 is substantially equal to the opening width of the opening window 2 in which the flange margin 3 is bent. The lower mold 9A can simultaneously bend the long-side linear portions 2A facing each other in parallel by a single press. Further, the convex portion 9a has a shape gradually narrowing toward both ends, has a plane shape of a boat shape, and has a central portion protruding in a mountain shape with respect to both ends, and has an inclined surface toward both ends. ing. As shown in FIGS. 13 and 14, the convex portion 9a of this structure can be folded without difficulty while gradually reducing the force applied to the flange margin 3 from the center of the chevron to both ends when pressing. There is a feature that can be tuned.

As shown in FIG. 12, the upper die 9B has a concave portion 9b at the center of the lower surface. The concave portion 9b is formed in a groove shape whose opening edge extends in parallel. The recess 9b is shown in FIG.
1 has a depth and a width that allow the projection 9a of the lower mold 9A to be inserted. Further, the upper die 9B shown in the figure is opened by extending both ends of the concave portion 9b to the side surface of the upper die 9B. As shown in FIG. 15, even when the front panel 1 is transported at a predetermined pitch, the bent flange margin 3 abuts on the lower surface of the upper mold 9B, as shown in FIG. It has the feature that it can be guided in the groove without making it.

The front panel 1 pressed by the above-mentioned mold 9
As shown by the arrows in FIG. 15, while being transported at a predetermined pitch, they are pressed one after another to form a flange margin 3 on the long-side linear portion 2A. The front panel 1 extends over the entire long-side straight portion 2 </ b> A except for the corner 12 of the opening window 2.
An inner bent flange margin 3 is formed.

The turret punch press 13 transfers the front panel 1 while pressing it at a frequency of 2 to 4 times per second, for example. Therefore, when pressing the front panel 1 having the entire length of the long side linear portion 2A of the opening window 2 of 1500 mm, the transfer pitch of the front panel 1 is 5 mm, and the punch frequency of the turret punch press 13 is three times per second. Then, a total of 300 hits can be made and press processing can be performed in about 2 minutes. However, the transfer pitch of the front panel 1, the punch frequency and the number of hits of the turret punch press 13 can be variously changed according to the total length of the opening window 2. As described above, the method of performing bending many times at a small pitch is simple and easy to use a small mold without using a special mold that is long and long, even in the case of the opening window 2 having a long overall length. The feature is that it can be pressed at low cost and in a short time.

FIG. 16 shows a front panel 1 in which the long side straight portion 2A of the opening window 2 is bent to form a flange margin 3. As shown in FIG. As shown in this figure, the front panel 1 in which the long side straight portion 2A is bent to form the flange margin 3 has a portion where the flange margin 3 is formed and a corner portion 12 which is not bent. The portion between them is stretched in a twisted state. This portion has a function of reducing the internal stress applied to the cutting edge 8 when the corner portion 12 is press-formed in the second pressing step. Therefore, there is a feature that the cutting edge 8 can be smoothly extended and extended, and the corner portion 12 of the flange margin 3 can be bent inward without difficulty.

[Second Pressing Step] The short side straight portion 2B of the rectangular opening window 2 opened in the front panel 1 and the through hole 6
Is pressed along the opening window 2 and bent inward to provide a flange margin 3. The front panel 1 is pressed so that the corner radius of the opening window 2 is about 5 mm, and a flange margin 3 bent inside is provided. The corner radius may be 3 to 20 mm, preferably 3 to 10 mm.

FIG. 17 shows the mold 9 used in the second pressing step.
And in the perspective view of FIG. FIG. 17 shows the lower mold 9A and FIG.
Indicates an upper mold 9B. As shown in FIG. 17, the lower mold 9A has a protrusion 9a at the center of the upper surface. However, also in this figure, in order to make the shape of the convex portion 9a easy to understand, the convex portion 9
"a" has shown the state which protruded. Lower mold 9A shown in FIG.
The left end of the projection 9a in the figure has a rectangular shape along the end of the opening window 2 where the flange margin 3 is bent, and the right end has a shape gradually narrowing. The convex portion 9a has a rectangular corner curved so that the opening window 2 to be press-formed has a predetermined corner radius. Further, the protrusion 9a has a rectangular portion protruding from an edge having a reduced width, and an inclined surface is provided toward the edge.

As shown in FIG. 18, the upper die 9B has a recess 9b in the center of the lower surface. The concave portion 9b is formed in a groove shape having an opening edge opened in a U-shape, and one end thereof is formed in an upper
It extends to the side and is open. The recess 9b is formed as shown in FIG.
Has a depth and a width into which the projection 9a of the lower mold 9A can be inserted. In the upper die 9B of this shape, the side of the concave portion 9b where the opening is not formed is a portion that bends the short side straight portion 2B. In the upper die 9B, the rectangular portion of the convex portion 9a of the lower die 9A is inserted into this portion, and the short side straight portion 2B and the corner portion 12 in which the through hole 6 is opened are shown in FIGS. Then, the flange portion 3 is bent inward as shown in FIG. Although the concave portion 9b shown in the figure has a corner formed at a right angle to form the corner portion 12 of the opening window 2, the concave portion is formed so that the opening window to be press-formed has a predetermined corner radius. It can also be curved.

The corner portion 12 of the flange margin 3 bent by the above-mentioned mold 9 is cut off at the cutting edge 8 as shown in FIG. However, the manufacturing method of the present invention does not press the front panel 1 in a state where the cutting edge 8 of the flange margin 3 is cut as in the related art. When the face panel 1 is pressed, the cutting edge 8 extends. Internal stress acts on the cutting edge 8 when it extends. This portion is cut only when the cutting edge 8 is extended and cannot be extended any further. Until the cutting edge 8 is cut, the cutting edge 8 is in a connected state, and a tensile stress acts on the cutting edge 8. The tensile stress acting on the cutting edge 8 acts to stretch the corner portion 12 of the flange margin 3. The cutting edge 8 is cut with the corner 12 stretched and no longer stretched. Cutting edge 8
Is cut without being cut to the limit, the corner portion 12 is stretched, and cut when the limit is exceeded. Thus, the tensile stress of the cutting edge 8 extends the corner portion 12 to the limit.

When the conventional front panel 1 provided with the notch 4 opening at the cutting edge 8 is pressed and bent inward, the bent flange margin 3 cuts the cutting edge 8 from the beginning. Therefore, no tensile stress acts on the cutting edge 8.
The notch 4 is expanded as the flange margin 3 bent inward is bent inward. When the notch 4 is expanded, a large tensile stress acts locally on the corner of the flange allowance 3. In particular, the flange portion 3 in which the notch 4 is provided in the corner portion has a narrower corner portion, so that the flange portion 3 concentrates on the corner portion of the narrow flange portion 3.
An extremely large tensile stress acts locally. The tensile stress concentrated here causes the corner portion of the flange margin 3 to break. For this reason, the front panel 1 provided with the notch 4 in the corner portion has a notch 4 with a small corner radius.
Therefore, it is impossible to prevent the broken portion from further extending toward the surface.

According to the manufacturing method of the present invention, the through hole 6 is provided in the corner portion 12, but the flange margin 3 is bent inward by press working in a connected state in which the cut edge 8 is not separated.
Therefore, the tensile stress acting when bending the flange margin 3 inward is not concentrated on the corner portion 12 of the flange margin 3. Further, since the flange margin 3 is bent inward after the connected cutting edge 8 is extended to the limit, the corner portion 12 is subjected to tensile stress acting on the cutting edge 8 until the cutting edge 8 is cut. To prevent breakage. Like the front panel 1 provided with the notch 4, the breaking force is not concentrated on the corners of the flange margin 3 from the beginning when the flange margin 3 starts to be bent inward. Further, after the cutting edge 8 of the flange margin 3 is extended to the limit and broken, the progress of the breaking toward the bending line 7 is prevented by the through hole 6. For this reason, the manufacturing method of the present invention uses the corner portion 1 of the flange allowance 3.
2 reliably prevents the broken portion from advancing further inward from the through hole 6.

Further, in the manufacturing method of the present invention, in the step of opening the through hole in the corner portion of the flange margin, the peripheral edge of the through hole may be bent inward to provide the reinforcing rib. The through-hole 6 shown in FIG. 22 is provided with a reinforcing rib 10 by bending a portion near the bending line 7 at the periphery of the through-hole 6 along the bending line 7. The reinforcing rib 10 is provided by bending the peripheral edge by, for example, press working.
The through-hole 6 having the reinforcing rib 10 at this position can more effectively prevent the breakage of the corner portion of the flange margin 3 when the bent flange 3 is formed by pressing the front panel 1. There are features that can be done. This is because the portion where the fracture is most likely to occur is reinforced by the reinforcing rib 10. Further, the corner portion that is difficult to break has a feature that the inside width (W1) can be widened to improve the appearance.

Further, according to the manufacturing method of the present invention, as shown in FIG.
Can also be provided. Since the through hole 6 of this structure is entirely reinforced by the reinforcing ribs 10, it is possible to effectively prevent the corner portion of the flange allowance 3 from being broken, and in addition to the tensile stress acting on the cutting edge 8. In addition, there is a feature that the limit point at which the corner portion is stretched and cut can be further extended. For this reason, there is a feature that the inner width (W1) is widened and the outer width (W2) is narrowed, so that the corner portion is hardly broken and the appearance can be improved.

Further, the reinforcing rib 1 shown in FIGS.
No. 0 is provided by bending the peripheral edge of the through hole 6 from the front side to the back side of the front panel 1. In these reinforcing ribs 10, the bent portion 6a at the periphery of the through hole 6 is curved, and does not become a sharp cut surface. Therefore, when the front panel 1 is press-worked and the bent flange 3 is provided, the through hole 6
Also, there is a feature that can improve the appearance of the portion approaching the bending line 7 and that can be seen from the surface of the front panel 1.

[Correcting Step] The flange margin 3 of the opening window 2 bent through the first pressing step and the second pressing step.
To correct the distortion. Since the front panel 1 on which the flange margin 3 is formed is pressed many times while shifting the position at a small pitch in the first pressing step,
A wavy distortion occurs in the flange margin 3 of the long side linear portion 2A. In this step, the wavy distortion of the formed flange margin 3 is corrected and flattened. The distortion of the flange allowance 3 is
For example, it is corrected by hitting with a hammer or the like. The distorted flange margin 3 can be flattened by hitting it with a hammer or the like from the back side in a state where a flat plate or table is in contact with the surface. In this way, the surface panel in which the distortion of the flange margin 3 has been corrected has a feature that the appearance of this portion can be improved and the commercial value can be further increased.

Step of Fixing Front Panel Provided with Flange Allowance to Door Frame The front panel 1 obtained by pressing and bending the flange allowance 3 inwardly has a glass plate 5 sandwiched in the opening window 2 and a door frame. Fixed to a flash door. The front panel 1 can directly clamp the glass plate 5 with the flange margin 3, or can clamp the glass plate via a clamping member.

FIG. 24 shows a flash door for holding a glass plate through a holding member. In the flash door shown in this figure, the glass plate 5 is sandwiched by the front panel 1 with a packing rubber 11 serving as a sandwiching member interposed at the boundary between the flange margin 3 and the glass plate 5. In the door shown in the figure, a glass plate 5 is sandwiched between two packing rubbers 11, and the glass plate 5 is arranged at a predetermined position of the opening window 2. Packing rubber 1
1 is formed in a frame shape having substantially the same size as the opening window 2. Further, the packing rubber 11 is extended in the surface direction of the front panel 1 and covers the surface of the flange margin 3. As described above, the flash door in which the glass plate 5 is disposed via the packing rubber 11 serving as the sandwiching member can effectively prevent the displacement and rattling of the glass plate 5, and
There is a feature that rainwater or the like can be prevented from entering the inside from this portion.

Further, since the flush door covers the surface of the flange margin 3 which is the inner side surface of the opening window 2 with the packing rubber 11 which is a sandwiching member, the external appearance of the entire opening window 2 including the corner portion. There is a feature that can improve. In particular, in the manufacturing method of the present invention, since the corner portion of the flange margin 3 is effectively prevented from being broken, the portion of the packing rubber 11 covering the flange margin 3 can be shortened to improve the appearance.

[0041]

The method for manufacturing a flash door according to the present invention comprises:
There is a feature that the corner radius of the opening window can be reduced to effectively prevent the broken portion of the corner portion from being extended to near the surface. That is, the manufacturing method of the present invention opens a through hole in a state where the cut edges of the corners serving as the flange margin of the front panel are connected, and presses the front panel processed in this state to bend inward. This is because the provided flange margin is provided. As the front panel is pressed in a state where the cut edges are connected, a tensile stress acts on the corner portion of the flange margin as it is bent. The tensile stress is distributed inside and outside the through hole. Tensile stress acting on the outside of the through hole, that is, on the cut edge portion of the corner,
The cut edge portion of the corner portion is extended to the limit to reduce the tensile stress acting on the inside of the through hole, thereby preventing breakage there. The cutting edge extends the corner without being cut to the limit and is cut when the limit is exceeded. After the cut edge breaks beyond the limit, the progress of the break is prevented by the through hole. Therefore, it is possible to effectively prevent the broken portion of the corner from being extended to near the surface.

Further, the method of manufacturing a flash door according to the present invention is characterized in that even a window having a different length can be easily and easily pressed to provide a bent flange margin. That is, the manufacturing method of the present invention presses the middle of the long side linear portion of the rectangular opening window opened in the front panel while shifting the position at a pitch of 1 to 20 mm to bend the flange margin inward. A first pressing step;
This is because the short side straight portion and the corner portion provided with the through hole are press-processed in the second pressing step of pressing the flange portion inward by bending the flange portion inward. In the manufacturing method in which the long side straight portion of the opening window is pressed at a small pitch in the first pressing step, bending can be performed by changing the number of times of pressing variously in accordance with the total length of the opening window provided with the flange margin. This eliminates the need for a plurality of types of large dies corresponding to the length of the opening window. In other words, one small die can easily perform press working according to the opening windows of various lengths. For this reason, there is a feature that the cost of equipment required for the mold is reduced, and even if the opening windows have various lengths, the flash door can be manufactured at a low cost by pressing at a low cost.

Further, in the method of manufacturing a flash door according to the present invention, in the first pressing step, the long side straight portion of the opening window is bent to form a flange margin. There is a feature that the portion between the corners that are not bent can be stretched in a twisted state. This portion can reduce the internal stress acting on the cut edge of the corner when the corner is press-formed in the second pressing step. For this reason, the manufacturing method of the present invention can smoothly extend and extend the cut edge, bend the corner part inward without difficulty, and provide a flange margin, and the broken part of the corner part extends to near the surface There is a feature that can be effectively prevented from being done.

Further, in the method for manufacturing a flash door of the present invention, a turret punch press machine is used to bend the flange margin in the press step, so that a complicated and high-cost press machine is used. There is a feature that processing can be performed easily, inexpensively, and efficiently in a short time. In particular, in the manufacturing method of the present invention, in the first pressing step, the middle of the long side linear portion of the opening window is 1 to 20 m
By pressing while shifting the position at the m pitch, it is possible to cope with opening windows of various lengths, so that a turret punch press can be ideally pressed using a small mold.

Furthermore, in the method for manufacturing a flash door according to the present invention, the distortion of the flange margin of the long side straight portion bent inward in the first pressing step is corrected in the correcting step. Flattened flange margin to improve the appearance,
Furthermore, it has the feature that a high quality flash door can be manufactured.

[Brief description of the drawings]

FIG. 1 is a partially enlarged perspective view of a flash door manufactured by a conventional method.

FIG. 2 is a plan view showing a notch provided in a corner portion of a flange margin according to another conventional manufacturing method.

FIG. 3 is a perspective view of a flash door manufactured by the manufacturing method according to the embodiment of the present invention.

FIG. 4 is a sectional view of the flash door shown in FIG. 3;

FIG. 5 is a plan view showing an example of a through hole opening at a corner portion of a flange margin.

FIG. 6 is a plan view showing another example of a through hole opening at a corner portion of a flange margin.

FIG. 7 is a plan view showing another example of a through hole opening at a corner portion of a flange margin.

FIG. 8 is a sectional view showing a step of pressing the front panel.

FIG. 9 is a schematic sectional view of a turret punch press used in the manufacturing method according to the embodiment of the present invention.

FIG. 10 is a plan view showing an opening window of the front panel.

FIG. 11 is a perspective view showing a lower mold of a mold used in a first pressing step.

FIG. 12 is a perspective view showing an upper die of a die used in a first pressing step.

FIG. 13 is a sectional view showing a state in which the front panel is pressed in the first pressing step.

FIG. 14 is a cross-sectional view showing a state where the front panel is pressed in the first pressing step.

FIG. 15 is a sectional view showing a state in which the front panel is pressed in the first pressing step.

FIG. 16 is a perspective view showing an opening window of the front panel pressed in the first pressing step.

FIG. 17 is a perspective view showing a lower mold of a mold used in a second pressing step.

FIG. 18 is a perspective view showing an upper die of a die used in a second pressing step.

FIG. 19 is a sectional view showing a state where the front panel is pressed in the second pressing step.

FIG. 20 is a sectional view showing a state where the front panel is pressed in the second pressing step.

FIG. 21 is a perspective view showing a corner part of a flange margin of the front panel pressed in the second pressing step.

FIG. 22 is a partial cross-sectional perspective view showing a state in which a reinforcing rib is provided in a through hole opening at a corner portion of a flange margin according to another embodiment of the present invention.

FIG. 23 is a sectional view showing another example of a through hole having a reinforcing rib.

FIG. 24 is a cross-sectional view of a flash door holding a glass plate via a holding member.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Front panel 2 ... Opening window 2A ... Long side linear part 2B ...
Short side straight portion 3 ... Flange allowance 4 ... Notch 5 ... Glass plate 6 ... Through hole 6a ... Bending portion 7 ... Bending line 8 ... Cutting edge 9 ... Mold 9A ... Lower die 9B ...
Upper die 9a ... Convex part 9b ... Concave part 10 ... Reinforcing rib 11 ... Packing rubber 12 ... Corner part 13 ... Turret punch press machine 14 ... Upper turret 15 ... Lower turret 16 ... Table 17 ... Transfer means 18 ... Clamp 19 ... Upper and lower stand 20 … Elastic body

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B21D 53/74 B21D 53/74 E06B 3/70 E06B 3/70 Z

Claims (1)

[Claims] An opening step of opening a rectangular opening window (2) in a metal front panel (1), and a corner portion (1) of the opening window (2).
2), which is located in the portion to be the flange margin (3), and the through hole (6) in a state where the cutting edge (8) of the corner is connected
And pressing the front panel (1) along the opening window (2), and bending inward so that the corner radius is 20 mm or less to provide a flange allowance (3). Fixing the front panel (1) provided with the flange margin (3) to the door frame, comprising: a turret punch press machine (13) in the pressing step; The flange part is bent, and the pressing process is to position the middle of the long side linear portion (2A) of the rectangular opening window (2) opened in the front panel (1) at a pitch of 1 to 20 mm. Pressing while shifting, flange cost
(1) First pressing step to bend the inside inward, and the short side straight part
(2B) A second pressing step of pressing the corner portion (12) provided with the through hole (6) and bending the flange margin (3) inward, and a long side straight line bent inward A method of correcting the distortion of the flange margin (3) of the part (2A).