JP3959685B2

JP3959685B2 - Compound door

Info

Publication number: JP3959685B2
Application number: JP2002311277A
Authority: JP
Inventors: 祐昌中本; 望増田; 一成名川
Original assignee: Wood One Co Ltd
Current assignee: Wood One Co Ltd
Priority date: 2002-10-25
Filing date: 2002-10-25
Publication date: 2007-08-15
Anticipated expiration: 2022-10-25
Also published as: JP2004143839A

Description

【０００１】
【発明の属する技術分野】
本発明は、ガラス板、アクリル樹脂などの有機ガラス板又は木質繊維板を組み組んだ複合ドアに関するものである。
【０００２】
【従来の技術】
従来、フラッシュドアにおいて、表面のパネルをくり抜き内部の芯組みで囲まれた部分に別のパネルを嵌め込んだドアや、框組みドアのように縦框と横框とに囲まれた部分にパネルを嵌め込んだドアは知られており、これら組み込まれるパネルとしてガラスを用いたものは知られている。
しかしながら、２以上の構成部材をガラス板、金属板、木質繊維板等の構成部材よりも厚さの薄いパネルを介して幅方向に一体的に結合・構成したドアについてはあまり知られていない。
【０００３】
【発明が解決しようとする課題】
木質材からなる２以上の構成部材をガラス板等の構成部材よりも厚さの薄いパネルを介して幅方向に結合してドアを構成する場合、それぞれの構成部材の結合すべき側に嵌合溝を設け、この嵌合溝にパネルの両側端を嵌め込んで接着固定している。このように、構成部材よりも薄手のパネルをドアに組み込む場合、パネルは構成部材と同等ないしはそれ以上の強度のある材質のパネルを使用する必要がある。一方、フラッシュドアのような木質ドアの場合、ドアを構成する芯材は限られた幅と厚みの木質材であることから、芯材に嵌合溝を設け、この溝にパネルを嵌め込むとドアの開閉時に溝部、特にドアの上下の嵌合溝に負荷が掛かり、この部分が破壊するという不具合が生じることがある。
本発明は、このような不具合のない複合ドアを提供するものである。
【０００４】
【課題を解決するための手段】
本発明の複合ドアは、２以上の構成部材と１以上のガラス板、木質繊維板等の構成部材よりも薄いパネルとからなり、構成部材の側端に設けた嵌合溝に前記パネルを嵌め込んでドアの幅方向に一体的に結合してなることを特徴とするものである。
【０００５】
【発明の実施の形態】
本発明において、構成部材はドアの上下に達する長さとし、その幅は主構成部材と副構成部材の様に少なくとも１個の構成部材が幅が大きく（幅広）、その他の構成部材は幅が小さい（幅狭）ものであってもよく、又、全て同じ大きさの幅の構成部材としてもよい。
構成部材は主として木質材で構成し、ドアの重量、意匠などの観点から主としてフラッシュドアと同様に芯材を組み付けたフレームに面材を張った構造のものとするが、中実の材、例えば、積層材、集成材、無垢材などの木質材で構成してもよい。また、目的に応じて金属製の構成部材としてもよい。これらのことから、副構成部材のうち、幅が比較的狭いものは積層材や無垢材などの一枚ものの板材を用いてもよい。
構成部材を構成するとき、構成部材よりも薄いパネル（以下単にパネルという）と結合させる側の構成材（芯材）は、嵌合溝を設けるためとパネルから受ける応力を支えるために、必要ならば、広い幅のものとするとか、樹脂含浸強化木材や強化プラスチック、アルミ等の金属、若しくはこれらの複合材としてもよい。
【０００６】
パネルとしては、ガラス、ポリカーボネイト、アクリル樹脂等の有機ガラス、強化プラスチック等の板や、アルミ板のような軽金属板や木質繊維板、樹脂含浸強化木質板などを用いることができる。パネルは、ドアの上下に達する長さと同一またはほぼそれに近い長さとし、幅は目的および材質に応じて選択する。厚さは特に限定されないが、通常、構成部材に設けた嵌合溝に嵌る厚さとする。しかし、完成された複合ドアの意匠、コスト、重量等の点でパネルの厚さは、構成部材：パネルの比で２：１〜５：１程度、特に４．５：１が好ましい。パネルは、すりガラス（曇りガラス）、着色ガラスなどの板や光輝金属板などとすることもできる。
【０００７】
複合ドアに占められるパネルの量は、ドアの幅方向の長さで、構成部材の合計量（合計幅）：パネルの幅＝１０：１〜２：１、好ましくは５：１〜３：１程度である。
本発明の複合ドアは、各構成部材のそれぞれのパネルと結合すべき側の端面にドアの上下方向に向けたパネルを嵌め込むための溝（嵌合溝）を設け、この嵌合溝にパネルの幅方向の両端を嵌挿することによって作る。パネルは通常、嵌合溝内で接着剤によって固定するが、パネルが金属板などの場合は構成部材の表面からのネジ止め等の方法によることもできる。
【０００８】
【実施例】
以下、本発明を図面にしたがって説明するが、本発明はこれらに限定されるものではない。
【０００９】
図１は、本発明の一実施例を示す正面図で、主構成部材をフラッシュドアの形式で作製した場合の例である。図１（Ａ）は複合ドアの構成前の状態を示し、１ａは面材および表面化粧シートを貼り付ける前の芯材を組み付けたフレームを示し、２ａは同様な副構成部材のフレームを示し、３はパネルを示す。図１（Ｂ）は、各フレームに面材を貼りその上に表面シートを貼った主構成部材１と副構成部材２を、パネル３を間に挟んで一体的に結合させた状態の複合ドア１０を示す。図中、４はドアの把手を示す。
【００１０】
図２は複合ドアの上面図で、図に示すように通常、パネル３は主構成部材１および副構成部材２よりも、厚さが薄く、また木質材からなる構成部材よりも剛性のあるものが使用され、ドアの開閉時の衝撃等により嵌合溝の幅を広げる方向に力が作用し、嵌合溝５の底部５１付近に亀裂６が生じることがある。この亀裂は主として、図１に破線の円で示す部分７、すなわちドアの上下の部分で応力が大となり生じ易い。本発明は、この問題を解決するために下記の種々の手段を講じている。
【００１１】
図１（Ａ）に示す主構成部材のフレームでは、通常横勝ちといわれる上下の横芯材１１が両側端の縦芯材１２を挟む形の長さとなっている。この場合、横芯材１１を図３に示すように木材の繊維方向が嵌合溝５の深さ方向と同じ方向となっている木材（無垢材）または積層木材、集成材を使用すると、木材の繊維によってパネルによる嵌合溝にかかる力が押さえられる。必要に応じて、上下の横芯材１１の上下方向の幅を大きくしてもよいし、横芯材に硬い南洋材を用いてもよい。
また、補強のために嵌合溝５に嵌装できる図示するような端面Ｕ字型の金属製の嵌合部材８を装着してもよい。嵌合部材８は横芯材１１にのみに装着されるものでもよく、また、横芯材１１と縦芯材１２を含めて嵌装できる長さとしてもよい。フレームを縦勝ちとした場合でも、嵌合部材８を縦芯材１２の嵌合溝５の上下に達する長さとしてもよく、上下の端部の溝５にのみ嵌装できる長さとしてもよいことは勿論である。なお、図示した嵌合部材８は芯材の表面を覆うフランジ（縁）を有するが、フランジの無い嵌合溝内に挿入されるコ字型の形状としてもよい。
【００１２】
図４は、主・副構成部材のフレーム１ａ、２ａを、通常縦勝ちといわれる、縦芯材１２をフレームの上下に達する長さとしたものの例である。この場合、嵌合溝を設ける縦芯材１２を通常の木材とすると、木材の繊維方向がドアの上下方向となり、芯材１２の幅（ドアの開閉方向の幅）が狭いことから嵌合溝を中心に芯材の幅方向に割れ易い恐れがある。
そのため、この形式のフレームの場合には、嵌合溝に図３に示した嵌合部材８を装着するとか、または縦芯材そのものをアルミ合金などの金属製とするか、強化プラスチック、積層木材、樹脂含浸強化木材等からなる芯材としてもよい。また、木質芯材の側面に前記強化木材やプラスチック材を貼り合わせた芯材とし、強化材に嵌合溝を設けるようにしてもよい。
【００１３】
応力のかかる箇所は主としてドアの上下の接合部であることから、構成部材１と２の間にパネル３を組み付けるにあたり、図５に示すようなコ字型の補強桟９をパネル３に冠着させるようにしてもよく、またパネル３の長さをドアの上下の長さよりも短くして、パネル３の上下に補強桟９ａとしてパネルと同じ厚さの角材を構成部材１と２に掛け渡すように装着してもよい。図６（Ａ）はコ字型の補強桟９の使用例を示し、図６（Ｂ）はパネル３と同じ厚さの角材からなる補強桟９ａの例を示す。
補強桟はアルミ合金等の金属製、プラスチック製でもよく、前記強化材で構成してもよい。
【００１４】
本発明の複合ドアに生じる応力はパネルの嵌合によって生じるものと考えられる。したがって、図７に示すようにパネルおよび嵌合溝の形状を調整することによってこれらの応力やせん断破壊を避けることができる。図７の▲１▼はパネル３の嵌合側端部の角を面取りした例であり、▲２▼は嵌合溝５の開口端を面取りした例であり、▲３▼は嵌合溝５の底部を挿入口より広くしてアリ溝形状とした例である。
これらは特に負荷のかかるドアの上下付近のみに形成してもよい。横勝ちの場合、横芯材にのみ形成すれば、手間および設備費をそれほどかけずに、ドアの上下付近にかかる負荷を調整できる。
このようにすることにより、ドア開閉時に生じる嵌合溝を中心として左右にかかる応力を緩和することができる。これら▲１▼から▲３▼は芯組みを横勝ちとしたとき特に効果を奏する。
パネルを固定するための接着剤は、特に限定されず芯材やパネルの材質に応じて選択されるが、好ましくは接着後の体積減少率の小さい接着剤、例えば、シリコーン系接着剤などが好ましい。
【００１５】
本発明は、構成部材の側面に嵌合溝を設け、この嵌合溝にパネルを嵌着してドアを構成することから、図８に示すように各構成部材１、２のフレームの表面に面材を貼り、その上に表面シート２０を貼るとき、シート２０の端部を嵌合溝５内に納めてパネル３を挿入して表面シートを貼りつけることができる。そのため、従来問題とされていた表面シートの端部の処理の問題を解消することができる。
【００１６】
以上、本発明をフラッシュドアの芯組みの例を挙げて説明したが、これに限定されることなく、框組みドアと同様な形式でも本発明は適用できる。本発明のドアを構成するには、ドアの構成部材を作製した後に縦芯材等に嵌合溝を設けてもよく、また、予め嵌合溝を設けた芯材を組み付けてフレームとし、フレームに面材および表面シートを貼り、パネルを嵌着して複合ドアを構成してもよい。
上記の例では、パネルが１枚の場合について説明したが、パネルを２枚以上とすることもできる。
【００１７】
【発明の効果】
本発明は、縦芯材、横芯材ともに特定の材質のものを選択して使用し、パネルの端部および嵌合溝の形状を工夫することによって、複合ドアの上下端付近に相当するパネルと構成部材、特に構成部材に設けた嵌合溝の上下端付近にかかる応力の偏在を調整し、バランスよく応力を分散させることができる。その結果、従来この種類のドアに起こりがちな上下端付近の破損が生じない丈夫なドアが得られ、パネルと構成部材との組み合わせによって従来にない新規な意匠のドアを得ることができる。
【図面の簡単な説明】
【図１】本発明の一実施例を示す正面図である。
【図２】複合ドアの上面図である。
【図３】横勝ち芯組みを示す部分斜視図である。
【図４】縦勝ち芯組みフレームを示す正面図である。
【図５】補強桟の施用例を示す部分断面図である。
【図６】補強桟を示す斜視図である。
【図７】パネルの嵌着状態を示す上面図である。
【図８】表面シートの張り付け方法を示す断面図である。
【符号の説明】
１主パーツ
１１横芯材
１２縦芯材
２副パーツ
３パネル
４把手
５嵌合溝
８嵌合部材
９補強桟[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a composite door in which a glass plate, an organic glass plate such as an acrylic resin, or a wood fiber plate is assembled.
[0002]
[Prior art]
Conventionally, in a flush door, the panel on the front surface is cut out and another panel is inserted in the part surrounded by the inner core, or the part surrounded by the vertical and horizontal planes, such as the side door. Is known, and those using glass as a panel to be incorporated are known.
However, little is known about a door in which two or more components are integrally coupled and configured in the width direction through a panel having a thickness smaller than that of components such as glass plates, metal plates, and wood fiber boards.
[0003]
[Problems to be solved by the invention]
When two or more structural members made of wood are combined in the width direction through a panel thinner than a structural member such as a glass plate, the door is configured to be fitted to the side of each structural member to be combined. A groove is provided, and both side ends of the panel are fitted into the fitting groove and fixed by adhesion. As described above, when a panel thinner than the constituent member is incorporated in the door, it is necessary to use a panel made of a material having a strength equal to or higher than that of the constituent member. On the other hand, in the case of a wood door such as a flash door, the core material constituting the door is a wood material of limited width and thickness, so if a fitting groove is provided in the core material and a panel is fitted into this groove, When the door is opened and closed, a load is applied to the groove portion, particularly the upper and lower fitting grooves of the door, and this portion may be broken.
The present invention provides a composite door free from such problems.
[0004]
[Means for Solving the Problems]
The composite door of the present invention comprises two or more constituent members and a panel thinner than one or more constituent members such as a glass plate and a wood fiber board, and the panel is fitted in a fitting groove provided at a side end of the constituent member. And is integrally coupled in the width direction of the door.
[0005]
DETAILED DESCRIPTION OF THE INVENTION
In the present invention, the constituent member has a length that reaches the top and bottom of the door, and the width of at least one constituent member is large (wide) like the main constituent member and the sub constituent member, and the other constituent members are small in width. (Narrow) may be used, or all of the members may have the same width.
Constituent members are mainly made of wood, and from the viewpoint of door weight, design, etc., it is assumed to have a structure in which a face material is stretched on a frame in which a core material is assembled in the same manner as a flash door, but a solid material, for example, Alternatively, it may be made of a wood material such as a laminated material, a laminated material, or a solid material. Moreover, it is good also as metal structural members according to the objective. For these reasons, a single plate material such as a laminated material or a solid material may be used as the sub-constituent member having a relatively narrow width.
When configuring the component, the component (core material) on the side to be joined to the panel thinner than the component (hereinafter simply referred to as the panel) is necessary to provide the fitting groove and to support the stress received from the panel. For example, it may be wide, or may be a resin-impregnated reinforced wood, reinforced plastic, a metal such as aluminum, or a composite material thereof.
[0006]
As the panel, glass, polycarbonate, organic glass such as acrylic resin, a plate made of reinforced plastic, a light metal plate such as an aluminum plate, a wood fiber plate, a resin-impregnated reinforced wood plate, or the like can be used. The length of the panel is the same as or nearly the same as the length reaching the top and bottom of the door, and the width is selected according to the purpose and material. Although thickness is not specifically limited, Usually, it is set as the thickness which fits into the fitting groove provided in the structural member. However, in terms of design, cost, weight, etc. of the completed composite door, the thickness of the panel is preferably about 2: 1 to 5: 1, and more preferably 4.5: 1, in the ratio of component: panel. The panel may be a plate made of frosted glass (frosted glass) or colored glass, a bright metal plate, or the like.
[0007]
The amount of the panel occupied by the composite door is the length in the width direction of the door, and the total amount of components (total width): panel width = 10: 1 to 2: 1, preferably 5: 1 to 3: 1. Degree.
The composite door of the present invention is provided with a groove (fitting groove) for fitting a panel directed in the vertical direction of the door on the end surface of each component member to be coupled with the panel, and the fitting groove has a panel. It is made by inserting both ends in the width direction. The panel is usually fixed in the fitting groove with an adhesive, but when the panel is a metal plate or the like, a method such as screwing from the surface of the constituent member may be used.
[0008]
【Example】
Hereinafter, the present invention will be described with reference to the drawings, but the present invention is not limited thereto.
[0009]
FIG. 1 is a front view showing an embodiment of the present invention, which is an example in which the main constituent members are produced in the form of a flash door. FIG. 1 (A) shows a state before construction of the composite door, 1a shows a frame assembled with a core material before attaching a face material and a surface decorative sheet, 2a shows a frame of a similar sub-constituent member, 3 shows a panel. FIG. 1 (B) shows a composite door in which a main component 1 and a sub component 2 each having a face material attached to each frame and a top sheet attached thereto are integrally coupled with a panel 3 interposed therebetween. 10 is shown. In the figure, 4 indicates a door handle.
[0010]
FIG. 2 is a top view of the composite door. As shown in the figure, the panel 3 is usually thinner than the main component 1 and the sub component 2 and more rigid than the component made of wood. And a force acts in the direction of widening the width of the fitting groove due to an impact at the time of opening and closing the door, and a crack 6 may occur near the bottom 51 of the fitting groove 5. This crack is likely to occur mainly due to a large stress in the portion 7 indicated by a broken-line circle in FIG. 1, that is, the upper and lower portions of the door. The present invention takes the following various means to solve this problem.
[0011]
In the frame of the main component shown in FIG. 1 (A), the upper and lower horizontal core members 11 that are usually said to be horizontal wins have a length that sandwiches the vertical core members 12 at both ends. In this case, when the horizontal core 11 is made of wood (solid wood), laminated wood, or laminated wood in which the fiber direction of the wood is the same as the depth direction of the fitting groove 5 as shown in FIG. The force applied to the fitting groove by the panel is suppressed by the fibers. If necessary, the vertical width of the upper and lower horizontal core materials 11 may be increased, or a hard southern material may be used as the horizontal core material.
Further, an end face U-shaped metal fitting member 8 that can be fitted into the fitting groove 5 for reinforcement may be mounted. The fitting member 8 may be attached only to the horizontal core material 11, or may have a length that allows the horizontal core material 11 and the vertical core material 12 to be fitted. Even when the frame is won vertically, the fitting member 8 may have a length that reaches the top and bottom of the fitting groove 5 of the vertical core member 12, or may be a length that can be fitted only in the groove 5 at the top and bottom ends. Of course. In addition, although the illustrated fitting member 8 has a flange (edge) that covers the surface of the core material, it may have a U-shape that is inserted into a fitting groove without a flange.
[0012]
FIG. 4 is an example of the main and sub-constituting members frames 1a and 2a, in which the vertical core member 12 is said to have a length that reaches the top and bottom of the frame. In this case, if the vertical core material 12 provided with the fitting groove is normal wood, the fiber direction of the wood is the vertical direction of the door, and the width of the core material 12 (the width in the door opening / closing direction) is narrow. There is a risk that the core material is likely to break in the width direction.
Therefore, in the case of this type of frame, the fitting member 8 shown in FIG. 3 is attached to the fitting groove, or the longitudinal core material itself is made of metal such as aluminum alloy, reinforced plastic, laminated wood Alternatively, a core material made of resin-impregnated reinforced wood may be used. Further, a core material in which the reinforced wood or plastic material is bonded to the side surface of the wooden core material may be used, and a fitting groove may be provided in the reinforcing material.
[0013]
Since the stressed part is mainly the joints at the top and bottom of the door, when assembling the panel 3 between the structural members 1 and 2, a U-shaped reinforcing bar 9 as shown in FIG. In addition, the length of the panel 3 may be shorter than the vertical length of the door, and square members having the same thickness as the panel as the reinforcing bars 9a are hung over the constituent members 1 and 2 above and below the panel 3. It may be attached as follows. 6A shows an example of use of the U-shaped reinforcing bar 9, and FIG. 6B shows an example of a reinforcing bar 9a made of square material having the same thickness as the panel 3. FIG.
The reinforcing bar may be made of metal such as an aluminum alloy or plastic, and may be made of the reinforcing material.
[0014]
The stress generated in the composite door of the present invention is considered to be generated by the fitting of the panels. Therefore, these stresses and shear fractures can be avoided by adjusting the shapes of the panel and the fitting groove as shown in FIG. (1) in FIG. 7 is an example in which the corner of the fitting side end of the panel 3 is chamfered, (2) is an example in which the opening end of the fitting groove 5 is chamfered, and (3) is in the fitting groove 5. This is an example in which the bottom portion of the ridge is made wider than the insertion port to have a dovetail shape.
These may be formed only near the top and bottom of a door that is particularly loaded. In the case of horizontal winning, if it is formed only on the horizontal core material, it is possible to adjust the load applied to the vicinity of the top and bottom of the door without much labor and equipment costs.
By doing in this way, the stress applied to the right and left around the fitting groove generated when the door is opened and closed can be relaxed. These (1) to (3) are particularly effective when the core structure is set to the horizontal.
The adhesive for fixing the panel is not particularly limited and is selected according to the core material and the material of the panel, but preferably an adhesive having a small volume reduction rate after adhesion, for example, a silicone-based adhesive. .
[0015]
In the present invention, a fitting groove is provided on the side surface of the component member, and a panel is fitted into the fitting groove to form a door. Therefore, as shown in FIG. When a face material is pasted and the surface sheet 20 is pasted thereon, the end portion of the sheet 20 can be placed in the fitting groove 5 and the panel 3 can be inserted to adhere the surface sheet. Therefore, the problem of processing the edge part of the surface sheet, which has been considered as a problem in the past, can be solved.
[0016]
The present invention has been described with reference to an example of the core structure of the flash door. However, the present invention is not limited to this, and the present invention can also be applied in the same form as the braided door. In order to configure the door of the present invention, a fitting groove may be provided in the vertical core material after the door constituent member is produced, or a frame is prepared by assembling a core material provided with a fitting groove in advance. Alternatively, a composite door may be configured by attaching a face material and a surface sheet to each other and fitting a panel.
In the above example, the case of one panel has been described, but two or more panels may be used.
[0017]
【The invention's effect】
In the present invention, a vertical core material and a horizontal core material are selected and used with specific materials, and the panel corresponding to the vicinity of the upper and lower ends of the composite door is devised by devising the shape of the end of the panel and the fitting groove. And the uneven distribution of the stress applied to the vicinity of the upper and lower ends of the fitting groove provided in the constituent member, particularly the constituent member, can be adjusted, and the stress can be distributed in a balanced manner. As a result, it is possible to obtain a durable door that does not cause damage near the upper and lower ends, which is likely to occur in this type of door in the past, and to obtain a door with a novel design that has not existed in the past by combining the panel and the constituent members.
[Brief description of the drawings]
FIG. 1 is a front view showing an embodiment of the present invention.
FIG. 2 is a top view of the composite door.
FIG. 3 is a partial perspective view showing a horizontal winning core structure.
FIG. 4 is a front view showing a vertical winning core frame.
FIG. 5 is a partial cross-sectional view showing an application example of a reinforcing bar.
FIG. 6 is a perspective view showing a reinforcing bar.
FIG. 7 is a top view showing a panel fitting state.
FIG. 8 is a cross-sectional view showing a method for attaching a top sheet.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Main part 11 Horizontal core material 12 Vertical core material 2 Subpart 3 Panel 4 Handle 5 Fitting groove 8 Fitting member 9 Reinforcement bar

Claims

It consists of two or more components that reach the top and bottom of the door and a panel that is thinner than one or more glass plates, wood fiberboards, etc., and the components are mainly made of wood and the thickness of the panel The total width of the panel occupying the door is less than or equal to half of the total width of the constituent members, and the side end portion of the panel is provided in the fitting groove provided on the side end of the constituent member. A composite door characterized by being fitted and integrally joined in the width direction of the door.

2. The composite door according to claim 1, wherein the constituent member is a member made of a wood material and having a face member stretched by assembling a core material like the flash door.

The two or more components are all the same width, or at least one is wide, and the amount of the panel occupied in the composite door (total width) is the length in the width direction of the door. The composite door according to claim 1, wherein the amount (total width): panel width = 10: 1 to 2: 1 .

The composite door according to claim 1, wherein the panel having a thickness smaller than that of the constituent member has a ratio of the thickness of the panel to the constituent member of 2: 1 to 4.5: 1.

The composite door according to claim 1, wherein the panel having a thickness smaller than that of the constituent member is a glass plate, a plastic plate, a metal plate, or a wood fiber plate.

The component member is made of a wood material, and a U-shaped or U-shaped metal fitting member is attached to the fitting groove provided on the side end of the member, so that the wider component member and the width thereof The composite door according to claim 1, wherein the narrow structural members are integrally coupled in the width direction of the door through a panel.

3. The composite door according to claim 2, wherein the core material on the side where the fitting groove of the component member is provided is metal, synthetic resin, reinforced wood, or a composite material thereof.

The composite door according to claim 1, wherein the fitting side end face of the panel is chamfered, the mouth of the fitting groove is chamfered, or the shape of the fitting groove is a dovetail groove.