JP2000282761A - Door having flush structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To constitute a door of only a short material and strengthen it against warpage, distortion and dislocation at an inexpensive cost by inscribing it between frame materials in the longitudinal direction, arranging a plurality of core materials in the short hand direction, substantially inscribing it between the frame material and the core material in the short hand direction and between the core materials in the short hand direction, and arranging the core material in the longitudinal direction. SOLUTION: The outer peripheries of the four sides of the right and left parts and the upper and lower parts of the door of flush structure whose inside has hollow structure are surrounded by four outer peripheral frame materials 3, 4, a surface material 1 and a reverse material are fixed on the surface and the reverse respectively, and core materials 5, 6 are arranged in the inside in the short hand direction and the longitudinal direction. The core material 5 in the short hand direction is inscribed between the outer peripheral frame materials 4 in the longitudinal direction, and a plurality of the core materials are arranged in one-pieces without being divided. The core material 6 in the longitudinal direction is arranged so as to be substantially inscribed between the frame material 3 and the core material 5 in the short hand direction and between the core materials 5, 5 in the short hand direction. Thereby expansion and contraction due to the variation per hour of the surface material and the reverse material are controlled by the core material in the longitudinal direction, and the occurrence of the warpage and flapping phenomena of the door can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fitting having a flash structure comprising outer and outer peripheral frames of a door, a longitudinal core, a lateral core, a surface material, and a back material. The present invention relates to a door for furniture or the like, which is extremely durable, having very little warpage due to aging and unevenness of the front and back surface materials.

[0002]

2. Description of the Related Art The core structure of a door is made of a plywood laminate, a glued laminated wood, a fiberboard, or the like as a core, a frame structure, or a so-called flash structure having a hollow structure inside. Various types have been conventionally known. Among them, those with a hollow flash structure can reduce the weight compared to the volume of the door, and are also relatively excellent in strength and durability, especially for domestically produced fittings and furniture. Doors have been used for a long time.

Further, a hollow structure, that is, a flash structure, has a paper core having a honeycomb shape or a roll shape as a core material, a plywood, an MDF, a particle board, a ground plate, or the like. Conventionally, a combination of a rectangular and elongated core material having a so-called rib shape in a vertical and horizontal direction has been often used. A core structure using a rib-shaped core material is generally composed of a combination of a core material in the longitudinal direction of the door, a core material in the short direction, an outer peripheral frame material, and front and back surface materials.

[0004] In addition, a structure often used in a rib-shaped core structure is conventionally composed only of an outer peripheral frame material and a short-side core material, and in many cases, there is no longitudinal core material. Although the structure combining the core materials was used for some wide-width doors, it was rare, and even if there was, the core material in the longitudinal direction was used as a single piece in the longitudinal direction of the door.

[0005]

SUMMARY OF THE INVENTION
The continuous version had the following disadvantages. That is,
The length of the core material in the longitudinal direction is substantially equal to the length of the door. For normal-sized doors and long doors other than the short door having a short door length, a long material is required and a defect-free material is required. Is required. Therefore, the cost was very high. Death on the core,
Defects such as decay, cracking, warping, twisting, and skew may cause the door itself to be warped, twisted, skewed, lack of strength, and the like.

[0006] The long defect-free material is not only expensive, but also for a core material that cannot be seen from the outside.
It was very difficult to obtain, there was a lot of problems with the use of defective materials, warpage of the door, and durability.

A conventional flash structure door is
Since the length of the core material is different between the longitudinal direction and the transverse direction, two types of core materials must be prepared, and further, there is a great deal of labor in assembling them vertically and horizontally. In addition, if the length of the core is different, it is difficult to mechanize the core, and an expensive mechanical device is required. In addition, there is a disadvantage that the cost is high if the operation is performed manually.

Therefore, it has been widely and generally used to form a flash structure using only the outer frame material and the core material in the short direction, but in this case, there were the following disadvantages. That is, since there is no core material in the longitudinal direction, the door is weak to warp in the longitudinal direction of the door, and due to the temporal change after the construction, irregularities of the door surface material and the back surface material are easily generated at the interval between the core materials in the lateral direction. , Looks unsightly,
In the worst case, it was unusable.

An object of the present invention is to solve the above-mentioned problems by the method described below, and it is an object of the present invention to eliminate the drawbacks of the conventional door structure of the flash structure. That is, a cored structure in only the short direction is susceptible to the warpage of the door, and the surface material and the back surface material are likely to have irregularities.

[0010] Further, even if the core material in the longitudinal direction is to be formed by a continuous single core material, a long straight material having no defects is required, and the cost is unnecessarily increased.
Good quality long materials are not only expensive but also difficult to obtain in recent years, and it is not advisable to add too much cost to the core material. The inventors of the present invention have made intensive studies to provide an inexpensive flash cored structure door that is made of only short material and is resistant to warping, twisting, and kinks, and have reached the invention described below.

[0011]

SUMMARY OF THE INVENTION The present invention relates to a door having a flash structure comprising four peripheral frame members, a longitudinally and laterally oriented core member inscribed therein, and a front and rear surface member. A plurality of core members in the hand direction are inscribed between the frame members in the longitudinal direction without being divided, and are arranged between the frame material in the short direction and the core material, and between the core materials in the short direction. And a door in which longitudinal core members are arranged substantially in contact with the door.

More specifically, by arranging the cores in both the longitudinal direction and the lateral direction, and by making the shapes and dimensions of the cores in the longitudinal direction and the lateral direction the same, the core material in the longitudinal direction is obtained. Inexpensive short materials can be used, and material costs can be reduced. Further, since a single core material is used for the core assembly operation, mechanization is easy, and a door having a flash structure can be manufactured extremely economically. Furthermore, since the core members are arranged in the longitudinal direction, the door itself is resistant to warping, and the occurrence of irregularities on the surface material and the back surface material can be prevented.

Further details will be described with reference to the drawings. FIG. 1 is a plan view showing an example of a flash core structure according to the present invention, and FIG.
3 is a cross-sectional view, and FIGS. 3 and 4 are plan views showing another example of the flash core structure of the present invention. FIG. 5 is an enlarged view of a main part showing a gap provided at a contact point of the core material. 6 and 7 are plan views showing one example of a conventional flash core structure. In the drawing, 1 is a front surface material, 2 is a back surface material, 3 and 4 are short and long outer peripheral frame materials, and 5 and 6 are short and long direction core materials, respectively. Reference numeral 7 denotes a void portion of the core contact of the present invention. Reference numeral 8 denotes a core structure of a conventional flash structure door, which is a single core material extending in the longitudinal direction.

The door of the present invention is a door having a flash structure in which the inside has a hollow structure. The outer periphery of the left, right, upper and lower sides of the door is surrounded by four outer peripheral frame members, and the front and back surfaces thereof Has a surface material and a back material fixed thereto, respectively. The inside thereof has a core material arranged in a lateral direction and a longitudinal direction, and has a so-called flash structure.

Further, a plurality of core members in the short direction are inscribed between outer peripheral frame members in the long direction, and a plurality of core members are arranged one by one without being divided. Further, the core members in the longitudinal direction are arranged between the frame members in the short direction and the core members in the short direction, and so as to be substantially inscribed between the core members in the short direction.

By arranging the core members in the longitudinal direction in this manner, it is effective to prevent the door itself from warping. That is, since the expansion and contraction of the front surface material and the back surface material due to the temporal change are suppressed by the longitudinal core material, the occurrence of the warpage of the door can be prevented, and the door is harder to warp than the material without the core material in the longitudinal direction. It is advantageous. In addition, unevenness due to a waving phenomenon caused by expansion and contraction of the front and rear members due to the temporal change of the core material in the short direction can be prevented by the core material in the longitudinal direction.

Next, a comparison between a case where the core material in the longitudinal direction is a single continuous long material and a case where the short material is substantially inscribed between the core materials in the short direction as in the present invention is general. The longer the core material itself, the longer the core material itself in the longitudinal direction. Conversely, the shorter the length of the core material, the smaller the degree of warpage. Furthermore, in the core structure of the present invention, the longitudinal core material is divided between the respective transverse core materials, so that the influence of the warp of the longitudinal core material itself can be dispersed, and the door warp can be prevented. It is very advantageous.

As described above, as the length of the core material in the longitudinal direction, the shorter the length, the more advantageous in the warping, and therefore, the more effective the core material in the warping of the door itself. As described above, the arrangement of a plurality of short members in the longitudinal direction of the core member in the longitudinal direction is stronger than that of the single long member in the longitudinal direction. Furthermore, a short material is cheaper than a long material, and it is very economically advantageous to be composed of only an inexpensive short material.

Further, the strength and rigidity are increased when the short core material in the longitudinal direction is arranged so as to be substantially inscribed in the core material in the short direction, rather than in the longitudinal direction. The durability of itself is improved.

The inner dimension between adjacent short cores substantially coincides with the length of the long core, and the length of the short core and the length of the long core are substantially the same. Are substantially the same, only one kind of core material is required, the flash core assembly operation itself can be easily mechanized, and the manufacturing cost can be greatly reduced, which is very economical. In other words, mechanization of two or more types of core material and core assembly is a very complicated operation for the machine,
Expensive machines and devices are required, which is very economically disadvantageous.

Further, if the core material is formed so as to form a gap between the contact between the core material in the short direction and the core material in the longitudinal direction inscribed in the short direction, the water content of the core material changes with time and the short direction causes Even if the core material extends in the width direction, or even if the longitudinal core material extends in the longitudinal direction, the gap provided at the contact point between the short direction core material and the long direction core material. As a result, no extra stress is generated inside the core structure. Therefore, a stable door with little warping, ablation, and twisting is generated without excessive force being generated inside the door.

Therefore, it is desirable that the contact point between the core material in the short direction and the core material in the long direction is provided with a gap.

The size of the gap is desirably 1.0 mm or more and 2.0 mm or less. If it is less than 1.0 millimeter, the void is too small to absorb the elongation of the core material in the short and long directions. On the other hand, if it is 2.0 mm or more, it is too large to absorb the dimensional change of the core material. If the gap is too large, the rigidity of the core structure itself is reduced, and the durability of the door is reduced. A good gap size is 1.0 mm or more and 2.0 mm or less. The basis is described below.

As the core material in the transverse direction, a plywood, a sawn board, a laminated wood, a fiberboard, a particle board and the like are usually used. The amount of expansion and contraction of these woody materials in the width direction due to the change in the water content is at most about 8% of the width dimension. That is, when the water content of the wood material changes from the equilibrium water content of about 11% to the fiber saturation point of about 28% by about 17%, the fiber expands and contracts by about 8%. On the other hand, the width of the core material in the short direction of the door is usually about 3
It is 0-45 mm.

Therefore, the amount of expansion and contraction caused by a change in the water content from an equilibrium water content of about 11% to a fiber saturation point of about 28% is about 2.4 to 3.6 millimeters. On the other hand, the expansion and contraction dimension in the length direction of the core material in the longitudinal direction is about 0.3% of the length dimension in a change in the water content from the equilibrium water content to the fiber saturation point. The length of the core material in the longitudinal direction is usually about 100 to 900.
Because of the millimeter, the dimensional change of the material per about 17% change in moisture content from the equilibrium moisture content to the fiber saturation point is about 0.3-2.7 millimeters.

Since these dimensional changes are absorbed at both ends of the core material in the longitudinal direction, the dimensional change per contact point between the core material in the short direction and the core material in the longitudinal direction is as follows. １ ／ of the maximum value of the dimensional change of
The maximum values of the dimensional change of the core material in the transverse direction and the longitudinal direction are 3.6 mm and 2.7 mm, respectively.
One-half of the sum of these values is about 3.15 millimeters. Therefore, the maximum required gap size is about 3.2 millimeters. The minimum value is similarly 1.4 mm.

On the other hand, the change in the water content of the door under daily common sense usage conditions is at most about 20% at most from the equilibrium water content, and it is sufficient to allow for a change of about 9%. . Therefore, the maximum value of the gap size is 9/17 of 3.2 mm, that is, 1.7 mm. The minimum value of the gap size is 1.4 mm.
/ 17, that is, 0.8 mm. Therefore, it is sufficient if there is a gap of about 0.8 to 1.7 mm. Since wooden doors are relatively flexible in their dimensional accuracy,
It is sufficient if the minimum value of the gap size in practical use is 1.0 mm or more. For the same reason, the maximum value of the gap size may be 2.0 mm.

Further, if there is a gap exceeding 2.0 mm, the rigidity of the door itself is reduced, and there is a problem in durability. A good dimension of the gap is not less than 1.0 millimeter and not more than 2.0 millimeter.

[0029]

The inner core structure of a conventional flash structure door is often composed only of a plurality of core members in the short direction. In this case, since there is no core member in the longitudinal direction, the length of the door is reduced. There is a drawback that it is weak to warp in the direction and that irregularities on the door surface material and the back surface material are easily generated at the interval between the core materials in the lateral direction. However, the door of the present invention can eliminate these disadvantages by arranging the core material also in the longitudinal direction, not only becomes strong against warpage in the longitudinal direction, but also the surface material due to the elongation and contraction of the surface material and the back material over time. This has the effect of preventing unevenness of the back material.

Further, since the door of the present invention is arranged such that the core material in the longitudinal direction is substantially inscribed between the core materials in the short direction, a durable door can be provided without a risk of lowering the rigidity of the door. Becomes In addition, the length of the core material in the short direction and the internal dimension between adjacent short core materials are substantially the same, and the length of the core material in the longitudinal direction is substantially the same as the length of the core material in the short direction. Therefore, only one kind of core material is required, and mechanization of the core assembly is easy, which is very economical.

Further, the core material in the longitudinal direction may be short in length, a short material can be used, and no expensive material such as a single-piece long material having no defects is required, which is very economical. is there. In addition, the combination of a plurality of short members is more advantageous in the longitudinal warping because the longitudinal warping is dispersed in the longitudinal direction than in the single through-hole. In addition, since a gap is provided at the contact point between the core material in the transverse direction and the core material in the longitudinal direction, even if the dimensional change due to the moisture content change of the core material occurs when the door is used for a long time, Since the change can be absorbed, a door with excellent long-term durability with very little warpage, twisting, or deviation can be realized.

[0032]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Doors for fittings or furniture vary in type, shape and size, but have a width of about 200-600 mm and a length of about 300.
~ 2400mm, thickness dimension is about 20 ~ 40
There are many millimeters. As surface material, back material,
Veneer boards, wood grain patterns or decorative boards such as monochromatic vinyl chloride sheets and printed sheets are often used. As the material used for the outer frame material, plywood, particle board, fiber board, OSB, wafer board, LVL, laminated wood, sawn board made of lumber, and composite materials thereof are preferred. used. Also, the same material as the outer peripheral frame material is often used as the core material in the longitudinal direction and the lateral direction. For example, LVL is used for the external frame material, and plywood, particle board, etc. is used for the inner core material. Combinations are also common.

Conventionally, the outer peripheral frame material is one of the seam pears.
A continuous material is used, and its size is often about 30 to 45 mm in width, about 300 to 2400 mm in length, and about 9 to 35 mm in thickness. On the other hand, the core material in the short direction is arranged in the width direction of the door, and the interval is 100 to
Many are 900 millimeters. At regular intervals,
It may be configured at different intervals. The size of the core material in the short direction is about 30 to 45 mm in width and about 110 in length.
Most are about 540 millimeters and about 9 to 35 millimeters thick.

The core material in the longitudinal direction is conventionally a single core material. However, in the present invention, the core material in the short direction is arranged so as to be inscribed in the core material in the short direction and is divided into a plurality of core materials. Therefore, although the size of the core material in the longitudinal direction varies depending on the size of the door and the thickness of the front and back material, the width is about 30 to 45 mm, the length is about 100 to 900 mm, and the thickness is about 9 to 35. There are many millimeters.

The gap between the core material in the short direction and the core material in the longitudinal direction inscribed in the short direction is 1-2 mm.
The gap of 1-2 millimeters is obtained by temporarily bonding a spacer having a thickness of 1-2 millimeters to both ends of the longitudinal end of the core material with double-sided tape. Remove.
It is common sense that the core material is made of a straight-through material as much as possible, and that a large defective material, that is, rot, dead node, broken material, warped torsion material, undried material having an abnormally high moisture content, etc. is not used. The water content is desirably 15% or less at the highest and 8% or more at the lowest.

If the core material in both the longitudinal and lateral directions has the same shape and substantially the same size, it is advantageous for mechanization of the core assembly.
At this time, if the inner dimension of the outer peripheral frame material in the transverse direction is not divisible by an integral multiple of the inner dimension of the outer peripheral frame material in the longitudinal direction, the fractional portion is substantially equally divided in the upper and lower directions at both ends of the door. Escape,
It is not necessary to arrange a longitudinal core material in this portion. Moreover, you may arrange | position. In the case of a wide door having a width of about 400 mm or more, it is desirable to arrange two or more rows of core members in the longitudinal direction.

It is preferable that the adhesive of the core structure of the flash structure door has good adhesiveness with the front surface material, the back surface material, the frame material, the core material, etc., and urea resin, melamine resin, acetic acid Any woodworking adhesive such as a vinyl resin, a phenolic resin, a resorcinol resin, a urethane-based resin, and a synthetic rubber-based resin may be used. Needless to say, the bonding condition is selected to be suitable for each adhesive.

[0038]

Next, the present invention will be described in detail with reference to examples. Example 1 A plywood material having a size of 20 × 45 × 2206 mm
A book and two plywood materials having a size of 20 × 45 × 460 mm are prepared and used as an outer frame material. 2.5 as backing material
Millimeter, 460 mm wide, 2296 mm long Prepare a single color printed decorative plywood,
As the surface material, one decorative laminated plate having the same size as the back material and having an oak veneer having a thickness of 0.2 mm was prepared. Furthermore, as a core material in the short direction, 20 × 30 × 370
Two millimeter-sized particle boards were prepared. The core material in the longitudinal direction is composed of four particle boards of 20 × 30 × 880 mm size and 20 × 30 mm.
X 377 mm particle size board
I prepared this book.

The core structure is as shown in FIG. 1. After these materials are cold-pressed using a urea-melamine adhesive, the surrounding four sides are cut in a regular size with a tenoner to obtain a thickness of 25.
One flash door with a millimeter width of 450 millimeters and a length of 2280 millimeters was produced. The bonding conditions were as follows: adhesive application amount 200 g / m ² , cold press pressure 2.5 kg / cm ² , pressing time 24 hours, temperature 2 degrees Celsius
It was 0 ° C. The core members in the transverse direction were arranged at an interval of two inner dimensions of 380 millimeters, and the inner dimensions with the outer peripheral frame material in the lateral direction were 883 millimeters.

Furthermore, the core material in the longitudinal direction is parallel to the outer peripheral frame material in the longitudinal direction, and is aligned in the short direction so as to be substantially vertically divided at the right and left positions in the width direction of the door at approximately three equal points. 2
A total of six pieces of three pieces were arranged while being substantially in contact with the core material. Its core structure was as shown in FIG. The gap at both ends of the core material in the longitudinal direction having a length of 377 mm was set to about 1.5 mm. Also, the gap at both ends of the core material in the longitudinal direction having a length of 880 mm was also set at about 1.5 mm. The way of forming the contact gap was adjusted with spacers interposed therebetween. And 25x450x22
An 80 millimeter sized flash door was made.

Example 2 Two 25 × 45 × 2380 mm LVL materials and a 25 × 45 × 200 mm LVL material
Two materials are prepared and used as an outer frame material. The size of the front and back materials is 2.5 × 290 × 2380 mm,
A backing material is a 0.1 mm thick mono-colored PVC bonded plywood, and a 0.2 mm thick wood grain pattern is used for the backing material.
A millimeter double ply sheet bonded plywood was used. Nine plywood materials having a size of 25 × 30 × 200 mm were prepared as the core material in the lateral direction.

Further, as the core material in the longitudinal direction, ten materials having the same size and the same material as the core material in the lateral direction were prepared. The core structure is as shown in FIG. 3. After these materials are cold-bonded with an aqueous vinyl urethane-based adhesive, the four surrounding sides are cut in a regular size with a tenoner to obtain 30 × 280 × 236.
A flush door for a folding door having a size of 0 mm was manufactured. The bonding conditions in the cold press are as follows:
g / m ² , cold press pressure 2 kg / cm ² , pressing time 16 hours, pressing temperature 25 ° C.

The core material in the transverse direction and the core material in the longitudinal direction are of exactly the same size and the same material, the pitch between the core materials in the transverse direction is 202 mm, and a spacer is provided at the contact point of the core material. −
A gap of about 1.0 millimeter was provided between them. Further, the core materials in the longitudinal direction were arranged in a line in a vertical line at a position approximately at the center at the left and right positions in the width direction of the door.

Comparative Example 1 Only the inner core structure was different from that of Example 1, and the other parts were completely the same as Example 1. That is, two plywood materials having a size of 20 × 45 × 2296 mm and two plywood materials having a size of 20 × 45 × 460 mm were prepared and used as outer peripheral frame materials.

One single-color printed plywood having a thickness of 2.5 mm, a width of 460 mm, and a length of 2296 mm was prepared as a back material. The surface material is the same size as the back material and has a thickness of 0.2 mm.
One piece of decorative plywood to which a veneer was attached was prepared. As the core material in the short direction, seven particle boards of 20 × 30 × 370 mm size were prepared. And
The inner dimension of the space between the cores in the transverse direction is 249.5 mm
It was set at equal intervals in torr.

The core structure is as shown in FIG. 6. After these materials are bonded using the same adhesive as in Example 1 under the same bonding conditions, the surrounding four sides are cut with a tenoner. Then, as in Example 1, a flash door having a size of 25 × 450 × 2280 mm was manufactured.

Next, in order to confirm the effect of the core structure of the present invention, the flash structure doors of Example 1 and Comparative Example 1 were used in an environment unfavorable for warpage in the longitudinal direction and unevenness of the surface material and the back surface material. For 2 weeks, and measured the warpage in the longitudinal direction and the amount of change in the unevenness of the front and back surfaces. Table 1 below shows the results of the change over time in the amount of unevenness of the surface material and the back surface material. FIG. 8 is a graph showing the results. Table 2 shows the change over time in the warpage value in the longitudinal direction.

As can be seen from Tables 1 and 2, and FIG. 8, Example 1 is different from Comparative Example 1 in the amount of warpage in the longitudinal direction and the amount of unevenness between the short core materials of the surface material and the back surface material. There have been significantly less improvements. The test environment condition was a temperature of 40.
° C and a relative humidity of 90%.

First, when examining the amount of change in the roughness of the front and back surface materials in Table 1, the value of the unevenness in Table 1 indicates the actual measured value of the unevenness. Indicates the amount of change. In Example 1, the amount of change in the unevenness of the surface material was only 0.9 mm even after 14 days, whereas in Comparative Example 1, it was 1.7 times larger than that of Comparative Example 1. -Tor has also changed. Further, in Example 1, the amount of change in the unevenness of the back material showed a maximum value of 0.4 mm on the lapse of 10 days, whereas Comparative Example 1
Then, on the 14th day, the maximum value was greatly changed to 2.7 mm. This is more clearly shown in FIG. 8 which is a graph of this.

Further, in Example 1, the unevenness value itself changed in the range of -0.7 mm to +0.2 mm for the surface material. The back material of Example 1 is +0.3 mm
Torr to +0.7 mm. on the other hand,
In Comparative Example 1, the surface material changed in the range of 0 to +1.7 mm. The back material of Comparative Example 1 is 0 to +2.7 mm.
In the range of Torr.

When the door is actually used, the upper and lower limits of the irregularities of the front and back members are in a range of about -1 to +1 mm. In addition, the practical limit value of the amount of change in unevenness is 1.0 millimeter or less. In Example 1, both the surface material and the back surface material are within these limits, and are used in a high-humidity environment for a long time. However, there is no practical problem. On the other hand, in Comparative Example 1, both the front and back materials greatly exceed this limit, which is a serious problem in practical use.

Next, looking at the warpage in the longitudinal direction according to Table 2, the maximum value of the warp after 14 days in Example 1 was 2.1 mm, whereas in Comparative Example 1, it was 2.1 mm. NO. Two specimens showed the maximum value of 9.2 mm after 10 days.

The size of the test door is 25 × 450 × 228.
0 mm, and for doors of this length, the limit of use of the warpage value in the longitudinal direction is usually 3.0 mm, and Example 1 is well within this criterion.
In this case, the standard is greatly exceeded, and there is a practical problem.

Next, Tables 1 and 2 show the results of a test performed under high humidity conditions in an environmental test chamber. Table 1

Table 2

[Brief description of the drawings]

FIG. 1 is a plan view showing an example of a flash core structure according to the present invention.

FIG. 2 is a sectional view showing an example of a flash core structure according to the present invention.

FIG. 3 is a plan view showing another example of the flash core structure of the present invention.

FIG. 4 is a plan view showing another example of the flash core structure of the present invention.

FIG. 5 is an enlarged view of a main part showing a gap provided at a contact point of a core material.

FIG. 6 is a plan view showing an example of a conventional flash core structure.

FIG. 7 is a plan view showing another example of the conventional flash core structure.

FIG. 8 is a graph showing the change over time in the amount of change in the front and back surfaces of the flash door.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Front surface material 2 Back material 3 Short outer peripheral frame material 4 Longitudinal outer frame material 5 Short lateral core material 6 Longitudinal core material 7 Void portion of core material contact point 8 Long straight through core Lumber

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2E016 HA09 JA01 JA11 JC00 JC07 KA01 KA07 LA01 LB12 LC03 LD02 MA11 NA01 QA13

Claims (4)

[Claims] 1. A door having a flash structure comprising four outer frame members, longitudinal and lateral core members inscribed therein, and front and rear members, wherein the core members in the lateral direction are separated. A plurality of pieces are inscribed between the frame members in the longitudinal direction without being arranged, and between the frame material in the short direction and the core material, and between the core material in the short direction, and substantially inscribed in the longitudinal direction. A door characterized in that core materials are arranged. 2. The length of the core material in the short direction and the internal dimension between adjacent short core materials substantially match, and the length of the short core material and the length of the long core material are substantially the same. The door according to claim 1, wherein: 3. A longitudinal core material is formed by forming a gap between a contact point between a lateral core material and a longitudinal core material and a contact point between a lateral frame material and a longitudinal core material. The door according to claim 1, wherein the doors are arranged. 4. The gap between the contact between the core material in the transverse direction and the core material in the longitudinal direction, and the gap between the contact between the frame material in the transverse direction and the core material in the longitudinal direction is not less than 1 millimeter and not more than 2 millimeters. 4. The door according to claim 1, wherein the door is provided.