JPH07305573A - Frameless door - Google Patents

Abstract

PURPOSE:To embody a door which is of a light weight and tenacious, can finish its side surface in a neat and beautiful design, and can be mass-produced at a low cost. CONSTITUTION:This frameless door is provided with a surface plate 12, a back plate 13, and a core member 6 provided in a hollow between the surface plate 12 and the back plate 13. Both sides of the surface plate 12 are bent in U-shape, and reinforcement parts with a specific thickness are formed on the both sides. An opening is formed between both sides, and the opening is blocked by the back plate 13. At the end edges of the bendings of the surface plate 12, connecting members 12A to connect both end edges of the back plate 13 are provided. The connecting members 12A of the surface plate 12 are bent to the inner side of the frameless door, the both end edges of the back plate 13 are connected to the connecting members 12A so as to form a hollow box form frameless door, and the core member 6 is fixed inside the frameless door.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a door, and more particularly to a frameless door without a frame.

[0002]

2. Description of the Related Art As shown in FIG. 1, a conventional metal door has a structure in which a surface plate 2 is fixed to a frame 1 framed in a rectangular shape. In the door shown in this figure, a rectangular frame 1 is formed with a C channel 3, and surface plates 2 are fixed to both sides of the frame 1. In order to fix the surface plate 2 to the peripheral edge of the frame 1, the surface plate 2 is bent with the frame 1 interposed therebetween. An edge 9 is attached to the C channel 3 in a U shape.

The manufacturing method and structure of the door shown in FIG. 1 have been sufficiently considered so far, and the cost has been reduced to a state close to the limit. Therefore, it is extremely difficult to further reduce the cost. This is because the heavy frame is assembled into a rectangular shape, which increases the raw material cost and the assembly processing cost. Therefore, the door shown in FIG. 1 cannot be mass-produced at a lower cost.

Since the door having the structure shown in FIG. 1 has a thick metal C channel 3 built in along the periphery thereof, it has a drawback that the whole weight becomes considerably heavy. For example, the total weight of a door in which a surface plate, which is a metal plate of 0.6 mm, is fixed to the C channel, is considerably heavy, about 40 kg. If the C channel is made thin to reduce the weight, there is a drawback that the strength is significantly reduced. This is because the C channel is used as a reinforcing material for the door.

Heavy doors require strong strength in the mounting area to the building. This is because a strong impact is given to the mounting portion when opening and closing the door. Therefore, not only the cost of the door increases, but also the cost of the mounting portion increases.

Further, the door having the structure shown in FIG. 1 has a drawback that the peripheral edge cannot be finished to have a neat and beautiful appearance. The surface plates 2 on both sides are bent, and another U-shaped edge 9 is inserted therein. The door having this structure has a drawback in that the formation of two grooves along the peripheral edge cannot be eliminated and the side surface cannot be finished to be smooth.

The present inventor has, in order to solve this drawback,
A frameless door having the cross-sectional structure shown in FIGS. 2 and 3 has been developed (Japanese Patent Application No. 5-345265). The frameless door shown in these figures is manufactured by connecting two door units 4. Each door unit 4 is a metal plate bent in the same shape.
Is fixed. The two surface plates 5 have a U-shaped cross section so as to have sufficient strength without using a frame. The U-shaped surface plate 5 has a shape in which a front surface H, a side surface S, and a back surface R of the door are continuous. However,
In this specification, one side of the door is the front side and the other side is the back side. The front surface plate 5 bent in a U-shape has a connecting portion 5A at its end for connecting the door units 4 to each other. The connecting portion 5A at the edge is not the peripheral edge of the door,
Located on the front surface H and back surface R of the door. The front surface plate 5 has different lengths from the front surface H and the back surface R, and one of them is extended longer than the other. This is because the door unit 4 is not connected at the same position on the front surface H and the back surface R. The connecting portion 5A of the surface plate 5 is
It is bent inside the door so that it does not protrude outside the door. The frameless door having this structure is manufactured by connecting the two door units 4 with the connecting portion 5A.

The frameless door having this structure is easily manufactured as shown in FIG. 2 in the following steps. The surface plate 5 cut into a predetermined shape is bent. The core material 6 is adhered to the inner surface of the bent front plate 5. The core material 6 adhered to the center of the frameless door is adhered to one of the surface plates 5. In the frameless door of FIG. 2, a core material 6 is adhered to a surface plate 5 of the upper door unit 4. Also,
The upper and lower door units 4 have a core member 6 on the side of the connecting portion 5A.
Is glued. As shown in FIG. 3, the connecting portion 5A of the surface plate 5 is connected and the central core material 6 is bonded to the surface plate 5 of the lower door unit 4. The connecting portion 5A of the door unit 4 shown in FIGS. 2 and 3 can be connected by inserting one into the other. However, in the frameless door having this structure, the connecting portion can be mechanically connected with adhesive or rivets or screws. The upper and lower edges of the door unit 4 are bent at the front surface plate 5 to form bent portions, and the bent portions are wrapped to connect the bent portions. The bent portions are connected by screws or fasteners penetrating therethrough, or by adhesive bonding.

[0009]

The frameless door which can be manufactured as described above can be easily manufactured by connecting the two door units 4. Door unit 4 is front plate 5
It can be easily manufactured by bending and fixing the core material 6. Therefore, the frameless door of this structure is simple and easy,
Moreover, it has the feature that it can be mass-produced at low cost. Further, since the surface plate 5 is bent in a U shape and connected in a box shape, it can be reinforced with sufficient strength without using a frame. Therefore,
It is a light and strong frameless door. Forming the front surface H, the rear surface R, and the side surface S by bending the surface plate 5 in a U-shape realizes not only the reinforcement of the door but also the finish of the side surface S neatly and beautifully.

However, the frameless door having this structure has a drawback that the boundaries of the connecting portions are exposed by extending vertically on both sides. There is no problem with a door that can make the most of the connecting part in the design. However, the boundary of the connecting portion restricts the design of the door, and there is a drawback that a neat design without vertical lines cannot be achieved.

Further, the frameless door of this structure is
As the core material, plastic foam such as urethane foam, styrene foam, and polyethylene foam can be used. When urethane foam is used as the core material, it is formed by injecting uncured urethane into the internal hollow portion formed by connecting two door units. The injected urethane is foamed and hardened in the hollow portion and adheres closely to the inner surface of the door unit and is filled without any gap. In the frameless door having this structure, it is difficult to completely prevent the leak from the connecting portion of the injected urethane foam. Urethane foam leaking from the joints is difficult to remove completely and reduces the clean surface finish of frameless doors. The frameless door with the structure shown in Fig. 3 with connecting parts on both sides has urethane foam leaking on both sides, so whichever surface is used for the front of the door, urethane foam leaks on the front of the door, creating a beautiful surface. There are drawbacks that are difficult to finish.

The present invention was further developed with the object of preventing this drawback, and an important object of the present invention is to make the door light and strong, and to make the front and side surfaces of the door clean and beautiful. It is to provide a frameless door that can be mass-produced at low cost.

[0013]

The frameless door of the present invention has the following unique structure in order to achieve the above object. (A) The frameless door includes a front plate 12 and a rear plate 1.
3 and a core member 6 arranged in a hollow portion formed between the front plate 12 and the back plate 13. (B) The surface plate 12 is bent in U-shape on both sides to form both sides of a frameless door having a predetermined thickness, and an opening is formed between both sides of the door. (C) The front plate 12 has a back plate 13 at the front edge of the bent portion.
12A is provided to connect both side edges of the. (D) The back plate 13 is fixed to the front plate 12, and the front plate 1
The back plate 13 is formed in an outer shape that can fix the opening of the front plate 12 so that the frameless door having a closed structure can be configured by the two and the back plate 13. (E) Both side edges of the back plate 13 are connected to the connecting portion 12A of the front plate 12 to form a hollow box-shaped frameless door.

Further, in the frameless door according to the second aspect of the present invention, the connecting portion 12A of the surface plate 12 has a stepped shape, and the stepped portion 12B formed in the stepwise shape has a through hole 12C. On the other hand, hooks 13A that are inserted into and connected to the through holes 12C of the step portion 12B are provided on both side edges of the back plate 13. The hook 13A of the back plate 13 is inserted into the through hole 12C of the front plate 12, and the back plate 13 is connected to the front plate 12.

Further, in the frameless door of claim 3 of the present invention, the core material 6 is made of a plastic foam such as urethane foam, styrofoam, or polyethylene foam filled between the front plate 12 and the back plate 13. .

[0016]

The frameless door having this structure is manufactured in the following steps as shown in FIG. Both sides of the metal plate are bent in a U shape, and a connecting portion 12A is provided at the tip edge of the bent portion to form the front plate 12. In the surface plate 12 shown in the figure, a mounting base 7 for fixing the hinge and the door lock is adhered and fixed inside the bent portions on both sides. The core material 6 is adhered and fixed to the inner surface of the surface plate 12. The thickness of the core material 6 is designed so that it can be bonded to the inner surfaces of the front surface plate 12 and the rear surface plate 13. A frameless door using urethane foam, styrofoam, foamed polyethylene or the like as the core material 6 has a front plate 12
It is not always necessary to bond the core material 6 to the above. The core material 6, which is a plastic foam, has a front plate 12 and a rear plate 13.
After being connected, the insides of the front surface plate 12 and the rear surface plate 13 are filled and foam-molded. The back plate 13 having an outer shape that closes the opening of the front plate 12 is manufactured.

As shown by the arrow in FIG. 4, the back plate 13 is pressed against the opening of the front plate 12, and both side edges of the back plate 13 are connected to the connecting portions 12 A of the front plate 12 to expose the back plate 13. It is fixed to the opening of the face plate 12. In the frameless door shown in FIG. 5, a through hole 12C is provided in the step portion 12B of the front plate 12 to form a connecting portion 12A, and the rear plate 13 is formed in the connecting portion 12A.
The back plate 13 is connected to the front plate 12 by inserting the hook 13A provided on the front plate 12. However, in the frameless door having this structure, both side edges of the back plate 13 can be mechanically connected to the connecting portion 12A of the front plate by adhesion or rivets or screws. As shown in FIG. 6, the upper and lower edges of the door unit are bent by bending the bent portions 12E of the front plate 12 as shown by the arrows so as to wrap each other as shown in FIG. The part 12E is connected by a screw or a fastener penetrating the part 12E, or is bonded and connected.

[0018]

Embodiments of the present invention will be described below with reference to the drawings. However, the embodiments described below exemplify a frameless door for embodying the technical idea of the present invention, and the present invention does not specify the structure and material of the frameless door to the following.

Further, in this specification, for easy understanding of the claims, the numbers corresponding to the members shown in the embodiments are referred to as "claims column", "action column", and "action column". It is added to the members shown in the section of "Means for Solving the Problems". However, the members shown in the claims are
It is by no means specific to the members of the examples.

The frameless door shown in FIGS. 4 and 5 has a front plate 12 and a rear plate 13 connected to each other and a core member 6 fixed therein. The front plate 12 and the back plate 13 are metal plates having a thickness of 0.6 mm. As the metal plate, a stainless plate, an iron plate or the like having a decorative sheet adhered to its surface, or an iron plate having a printed pattern on its surface can be used. However, the frameless door of the present invention does not specify the material and thickness of the front plate 12 and the rear plate 13. As the front plate 12 and the back plate 13, a metal plate of 0.3 to 1.6 mm, a hard plastic plate, a plywood, or the like can be used.

FIG. 8 shows a developed view of the surface plate 12, that is, a shape before bending. The surface plate 12 in this figure has an opening 12F for fixing the door lock on the right side surface and a hole 12G for fixing the hinge on the left side surface. As shown in the cross-sectional view of FIG. 4, the surface plate 12 shown in this figure has both sides bent in a U-shape. The front plate 12, which is bent in a U shape, has a shape in which the entire front surface of the door, both side portions and the side surfaces of the rear surface are continuous. The back plate 13 is attached to the bent front edge of the front plate 12.
In order to connect to each other, the bent tip edge is provided with a connecting portion 12A.

The connecting portion 12A has a back plate 1 in the through hole 12C.
The hook 13A of No. 3 is inserted and connected. The structure of the connecting portion 12A is shown in FIGS. 5 and 9. The connecting portion 12A shown in these drawings has one bent edge of the surface plate 12 bent stepwise toward the inside of the door, and a through hole 12C is provided in a stepped portion 12B bent stepwise. There is.

Both sides of the back plate 13 are bent at right angles, and hooks 13A which can be inserted into the through holes 12C of the front plate 12 are projected. The hook 13A is provided at a position where it can be inserted into the through hole 12C. Furthermore, the hook 13A has a tip bent at an acute angle so that the hook 13A cannot be pulled out after being inserted into the through hole 12C. The hook 13A formed by bending the metal plate becomes thin when it is inserted into the through hole 12C. If it projects from the through hole 12C, it elastically spreads as shown in FIG. The connecting portion 12A of this structure has a feature that the hook 13A can be inserted into the through hole 12C and the two door units can be connected easily and easily and securely so as not to come off.

However, the present invention does not specify the structure of the connecting portion 12A to the above-mentioned shape. One of the connecting portions 12A shown in FIG. 10 is bent in a stepwise manner, and the other is bent into a shape in which they are in close contact with each other. The connecting portion 12A of this structure can be adhered and firmly connected. Further, the connecting portion 12A has a screw 1 as shown in FIG.
It is also possible to connect with 0. Although not shown, rivets may be used instead of screws. Also, the surface plate 1
A frameless door that uses a metal plate for 2 has a connecting portion 12
It is also possible to weld and connect A.

When the connecting portion 12A is mechanically connected by using a screw or a rivet, or by welding, there is a feature that the front plate 12 and the rear plate 13 can be firmly and surely connected. As shown in FIG. 11, the frameless door that connects the connecting portions 12A with a structure such as screws, rivets, and welding can fix the decorative molding 11 to the connecting portions 12A and hide the screws and the like to make a beautiful decoration. There are features.

Further, as shown in FIGS. 12 and 13, the front plate 12 may be provided with a connecting piece 12D at the tip of the connecting portion 12A, and the connecting piece 12D may be connected to the back surface of the front plate 12. The surface plate 12 of this structure can be reinforced by connecting the ends in a box shape. Therefore, there is a feature that the strength of the frameless door can be remarkably improved. The connecting piece 12D can be connected to the back surface of the front plate 12 by adhesion or by welding.

Further, FIG. 14 shows a specific example in which the surface plate 12 is a plywood. The surface plate 12 is made by adhering a flexible surface sheet (not shown) to the surface of the plywood. The surface plate 12 is provided with a V groove in the plywood while leaving the surface sheet, and the V groove is adhered and bent at a right angle as shown in FIG. 14 to form a connecting portion 12A. A connecting piece 12D is provided on the leading edge of the connecting portion 12A. The connecting piece 12D is adhered and fixed to the inner surface of the surface plate 12. The two surface plates 12 are the connecting portion 1
2A is bonded to form a frameless door.

The core material 6 is bonded to the inner surface of the face plate 12.
As the core material 6, flame-retardant paper connected in a honeycomb shape or a lattice shape, an inorganic foam, a plastic foam, or the like can be used. A flame-retardant frameless door can be obtained by using a flame-retardant material for the core material 6 and a metal plate for the surface plate 12. Urethane foam is most suitable as the plastic foam used for the core material 6. Urethane foam consists of front plate 12 and back plate 1.
3 can be connected, and uncured urethane can be injected into the hollow part to fill the space without gaps. The urethane filled in the hollow portion is foamed and filled in every corner, and is filled in the inner surfaces of the front plate 12 and the back plate 13 without any gaps. Instead of urethane foam, plastic foam such as expanded polystyrene and expanded polyethylene can also be used as the core material.

Inside the surface plate 12, a mounting base 7 for fixing the hinge and the door lock 8 is fixed. The hinge mount 7 has a box shape and is fixed to the side surface of the surface plate 12 by adhesion.
The mounting base 7 is provided with a screw hole for screwing the hinge.

As shown in FIG. 15, the door lock mounting base 7 is also box-shaped, and is fixed to the inner surface of the surface plate 12 by adhesion. The side surface S of the surface plate 12 is provided with an opening through which the door lock 8 is inserted. Also, the mounting base 7 for the door lock 8
Is formed by a U-shaped curved portion 7A and a box 7B that houses the door lock 8, and the U-shaped curved portion 7A is provided with an opening 7C into which the door lock 8 is inserted. A door lock 8 is fixed to the mount 7 as shown by a chain line. The door lock 8 is fixed inside the face plate 12 before the core material 6 is bonded. However, the door lock may be attached after the attachment base 7 and the surface plate 12 are adhesively fixed.

The surface plate 12 having both sides bent in a U-shape has an opening between the front edges of the bent portion. The back plate 13 is manufactured to have a width that can close the opening. As shown by the alternate long and short dash line in FIG. 16, the back plate 13 has side edges bent at right angles, and hooks 13A that can be inserted into the through holes 12C of the front plate 12 are provided at the bent front edges so as to project.

The back plate 13 is pressed and connected to the front plate 12 to which the core member 6, the mount 7 and the door lock 8 are fixed, as shown by the arrow in FIG. The back plate 13 pressed in this state has the hook 13A and the through hole 12C of the step portion 12B.
And is connected to the face plate 12. When connecting the back plate 13 to the front plate 12, the core member 6 fixed to the front plate 12
Applies an adhesive to the surface to be bonded to the back plate 13, and also bonds the core material 6 to the back plate 13 with the adhesive. However, the core material 6 in the central portion of the frameless door can be bonded to the front plate 12 and the rear plate 13 when the rear plate 13 is connected to the front plate 12.

After connecting the back plate 13 to the front plate 12, the bent portions 12 provided at the upper and lower edges of the front plate 12 and the back plate 13.
Wrap E as shown in FIG. The wrapped bent portion 12E is connected by a stopper penetrating therethrough. Optimally, the fasteners should be flared at both ends to connect the wraps. However, the wrap portion may be connected by using tap screws or an adhesive material instead of the stopper, or by using these together. The frameless door in which the bent portion 12E is connected can be reinforced by connecting the surface plate 12 in a box shape.

In the frameless door manufactured as described above, since the front plate 12 and the rear plate 13 are connected to each other on the back surface of the door, a linear connecting line appears along the connecting boundary. . The decorative mall 11 is fixed to the connecting line,
Alternatively, a surface sheet can be stretched to finish the surface.

Further, in the frameless door of the present invention, as shown in FIG. 17, the back plate 13 can be connected to the connecting portion 12A of the front plate via the connecting member 14. In the frameless door shown in this figure, the outer shape of the back plate 13 is designed to be slightly smaller than the opening of the front plate 12, and after connecting the back plate 13 to the front plate 12 via the core material 6, the back plate 13 The connecting member 14 is adhered to both side edges and the connecting portion 12A of the surface plate. The connecting member 14 can be connected to the front plate 12 and the back plate 13 by a structure such as welding, screwing, and riveting. The frameless door having this structure can be made into a frame door in which the central portion of the door is recessed by the back plate 13 fixed so that a step can be formed.

As shown in FIG. 17, in the frame door in which the back plate 13 forms a step, the back plate 13 is extended from the upper end to the lower end of the door. As shown by the chain line in FIG. 8, it is not possible to use a frame door in which a recess is provided only in the central portion. As shown in FIG. 8, the frame door provided with a concave portion only in the central portion is shown in FIG.
As shown in FIG. 5, the surface plate 12 can be manufactured by providing a recess.
In the frame door shown in the cross section of FIG. 18, the center of the face plate 12 is cut and the step plate 15 is attached to the molding 1 as shown by the chain line in FIG.
It is connected to the surface plate 12 via 6. The step plate 15 can be fixed to the core material 6. Surface plate 12 and step plate 15
The door for fixing the molding 16 between the molding plate 1 and the step plate 15 has a gap between the surface plate 12 and the step plate 15.
Can be closed at 6. Therefore, the plate material obtained by cutting the surface plate 12 can be used as the step plate 15.

[0037]

The frameless door of the present invention can be made sufficiently strong by omitting a thick and sturdy frame, which is a structural material indispensable for conventional doors.
Therefore, there is a feature that the total weight can be remarkably reduced. By the way, the frameless door of the present invention prototyped by the present inventor uses the same surface plate and core material as those of the conventional door, and the total weight can be significantly reduced to about 25 kg.
Since the conventional door has a total weight of about 40 kg, the frameless door of the present invention can be reduced in weight by 15 kg. Further, the frameless door of the present invention has a feature that it can be made sufficiently strong even though it can be remarkably reduced in weight by omitting the frame. It does not connect two face plates at the edge of the door like a traditional door,
This is because both sides of the face plate are bent in a U shape.
The surface plate bent in a U-shape has the shape of a reinforcing rib and has a tough structure. Therefore, the frameless door of the present invention has a feature that it can be made lightweight and sturdy.

Furthermore, a remarkable feature of the frameless door of the present invention is that it can be mass-produced easily and inexpensively. Unlike conventional doors, it is not necessary to connect a thick and sturdy frame like a frame and fix the surface plate to it, but it is possible to manufacture a frameless door by connecting the back plate to the bent surface plate. Is. The frameless door of the present invention which can be manufactured in this manner not only simplifies the manufacturing process, but also can be made lightweight and material cost can be reduced.

Further, the frameless door of the present invention has a feature that the entire front surface and side surfaces of the door can be beautifully finished. This is because it is not necessary to connect the front surface plate and the rear surface plate to the side surface and the front surface.

Furthermore, the frameless door of the present invention is
Since the connecting part of the front plate and the back plate is exposed on one side of the door, use urethane foam as the core material, and when pouring urethane, even if some leakage from the connecting part occurs, the connecting part will be on the back of the door. The feature is that the front surface can be finished very beautifully by using it. In addition, since the connecting line does not appear on the entire front surface, the connecting line does not restrict the design of the front surface of the door, and the front surface has an extremely beautiful design.

Further, in the frameless door according to claim 2 of the present invention, since the hook of the back plate can be inserted into the through hole of the front plate and the back plate can be connected to the front plate, the back plate can be very easily exposed. It has the feature that it can be connected to the fixed position of the face plate.

Further, since the frameless door according to claim 3 of the present invention uses urethane foam as the core material,
The core material can be filled in all the gaps between the front surface plate and the back surface plate without any gap, and the core material can be adhered to the inner surfaces of the front surface plate and the back surface plate without any gap.

[Brief description of drawings]

FIG. 1 is a sectional view showing an example of a conventional door.

FIG. 2 is a horizontal sectional view showing an assembled state of a conventional ramless door.

FIG. 3 is a horizontal sectional view of the frameless door shown in FIG.

FIG. 4 is a sectional view showing an assembled state of the frameless door according to the embodiment of the present invention.

5 is a cross-sectional view of the frameless door shown in FIG.

FIG. 6 is a perspective view of a surface plate of the frameless door shown in FIG.

FIG. 7 is a vertical sectional view of the frameless door shown in FIG.

FIG. 8 is a plan view showing a developed surface plate.

FIG. 9 is an enlarged perspective view showing a connecting portion of the front plate and a hook portion of the rear plate.

FIG. 10 is a cross-sectional view showing a connecting portion having another structure.

FIG. 11 is a cross-sectional view showing a connecting portion having still another structure.

FIG. 12 is a cross-sectional view in which a connecting piece is bonded and connected to the back surface of the front plate.

FIG. 13 is a cross-sectional view in which the connecting piece is connected to the back surface of the front plate with a screw.

FIG. 14 is an enlarged sectional view showing a specific example of a door having a plywood surface plate.

FIG. 15 is a sectional view of a portion for fixing a door lock.

FIG. 16 is a plan view showing a state where the back plate is expanded.

FIG. 17 is a sectional view of a frameless door according to another embodiment of the present invention.

FIG. 18 is a sectional view of a frameless door according to another embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Frame 2 ... Surface plate 3 ... C channel 4 ... Door unit 5 ... Surface plate 5A ... Connection part 6 ... Core material 7 ... Mounting base 7A ... U-shaped curved part 7B ... Box
7C ... Opening part 8 ... Door lock 9 ... Edge 10 ... Screw 11 ... Mall 12 ... Surface plate 12A ... Coupling part 12B ... Step part 12C ... Through hole 12D ... Coupling piece 12E ... Bending part 12F ... Opening part 12G ... Hole 13 Back plate 13A Hook 14 Connecting member 15 Step plate 16 Mold

Claims (3)

[Claims] 1. A frameless door having all of the following configurations. (A) The frameless door has a front plate (12) and a back plate (1
3) and a core material (6) arranged in a hollow portion formed between the front plate (12) and the back plate (13). (B) Both sides of the surface plate (12) are bent in a U-shape to form both sides of a frameless door having a predetermined thickness, and an opening is formed between both sides of the door. (C) The front surface plate (12) is provided with a connecting portion (12A) for connecting both side edges of the back surface plate (13) at the tip edge of the bent portion. (D) The back plate (13) has an outer shape that can be fixed to the opening of the front plate (12). (E) A hollow box-shaped frameless door is constructed by connecting both side edges of the back plate 13 to the connecting portion 12A of the front plate 12. 2. The front plate (12) has a connecting portion (12A) having a stepped shape, and a step portion (12B) formed in a stepwise shape is provided with a through hole (12C), and a back plate (13). Hooks (13A) that are inserted and connected to the through holes (12C) are provided on both side edges of the hook.
Insert the (13A) into the through hole (12C) and replace the back plate (13) with the front plate (12).
The frameless door according to claim 1, which is connected to the frameless door. 3. The core material (6) is a plastic foam selected from the group consisting of urethane foam, expanded polystyrene and expanded polyethylene filled between the front plate (12) and the back plate (13). Frameless door.