JP2001003476A - Wall panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate the fitting to a framework and enhance the airtightness in a wall panel comprising a heat insulating material on a plate body by forming a swollen part substantially in the center of the outer end surface of the heat insulating material along the outer edge of the heat insulating material. SOLUTION: In the end surface S5 of a heat insulating material 20, the part corresponding to a vertical surface 35 is protruded outward by the presence of a pair of inclined surfaces 36, 37. In both lateral end surfaces 5S of each heat insulating material 20, a trapezoidal sectional swollen part 38 is formed in the part except both first cutout parts 27. This swollen part 38 is formed substantially in the thickness directional center of the heat insulating material 20 extending over the whole circumference thereof. Further, the swollen part 38 is formed of the same material as the heat insulating material 20, and integrally molded with the heat insulating material 20. Therefore, the swollen part 38 is elastically deformable. Since the swollen part extending along the outer edge is formed substantially in the center of each end surface of the heat insulating material, the projected area of the indoor side surface of the heat insulating material can be made smaller than that of the setting space.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wall panel used for a wooden house.

[0002]

2. Description of the Related Art Conventionally, this type of wall panel is arranged in a space formed by an interior material and an exterior material for the purpose of improving heat insulation. In this wall panel, a heat insulating material is bonded to a wooden plate using an adhesive. Then, the heat insulating material is fitted into the installation space formed in the frame.

[0003]

However, in the prior art wall panel, the outer end surface of the heat insulating material has a flat shape, and the angle between the indoor side surface and the outdoor side surface of the heat insulating material is a right angle. Therefore, it is difficult to fit the heat insulating material into the installation space. In addition, if the insulation is fitted in an inclined state, a slight gap is created between the frame and the insulation,
The airtightness may be reduced.

[0004] The present invention has been made in view of the above problems, and an object of the present invention is to provide a wall panel which is easily fitted to a frame and has high airtightness.

[0005]

According to a first aspect of the present invention, there is provided a wall panel provided between a frame of a wooden house and a heat insulating material provided on a plate-like body.
The gist of the invention is to have a bulge formed substantially along the outer edge of the heat insulating material at a substantially central portion of the outer end surface of the heat insulating material.

According to the invention described in claim 2, in the wall panel described in claim 1, the gist is that the bulging portion is provided over the entire circumference of the heat insulating material. According to a third aspect of the present invention, in the wall panel according to the first or second aspect, the bulging portion is made of the same material as the heat insulating material, and is formed integrally with the heat insulating material. And

Hereinafter, the "action" of the present invention will be described. According to the first aspect of the present invention, the bulging portion is provided substantially at the center of the outer end surface of the heat insulating material. for that reason,
The heat insulating material can be smoothly fitted into the frame.
Moreover, since the outer end surface of the heat insulating material is in close contact with the frame, high airtightness can be secured.

According to the second aspect of the present invention, since the bulging portion extends over the entire circumference of the heat insulating material, the heat insulating material can be more smoothly fitted into the shaft assembly. With it,
The outer end surface of the heat insulating material is in close contact with the shaft around the entire circumference.
As a result, it is possible to ensure higher airtightness.

According to the third aspect of the present invention, since the bulging portion is made of the same material as the heat insulating material and is formed integrally with the heat insulating material, the production becomes easy.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows a front view of a wall panel 11 viewed from the indoor side of a wooden house. FIG.
FIG. 2 shows a plan sectional view of the wall panel 11. FIG. 10 shows a rear view of the wall panel 11 viewed from the outdoor side of the wooden house. As shown in FIGS. 1 and 2, the wall panel 11 includes a plate-shaped body 12 constituting an outer surface thereof, and the plate-shaped body 12 is formed from a medium density fiberboard (MDF). Have been. This medium fiber board is obtained by hardening crushed vegetable fiber (hemp fiber, bamboo fiber, coconut fiber, or the like).

As shown in FIG. 10, the plate 12 is provided on a frame 13 of a wooden house. Both upper and lower edges of the plate-shaped body 12 are fixed to a horizontal member 15 such as a beam or a base which constitutes the frame 13. The left and right edges of the plate 12 are fixed to the pillar 14. A nailing marking 16 is written on the outdoor side surface S11 of the plate-like body 12 along the periphery thereof. This marking 16 for nailing
It is composed of a plurality of points 16a. Each point 16a has a circular shape with a diameter of about 5 mm, and is all printed. Each point 16a is equally spaced on the same straight line (about 8 in this embodiment).
0-100 mm).

As shown in FIGS. 1 and 2, one wooden stud 17 extending along the longitudinal direction of the panel is joined to the center of the indoor side surface S12 of the plate-like body 12. FIG. 3 (c)
As shown in the figure, the stud 17 is made of a laminated material having a rectangular cross section. The glued laminated wood is formed by bonding a plurality of plate materials 18 which are overlapped with each other with an adhesive. The respective plate members 18 are stacked along a direction parallel to the plate-like body 12. The reason why the plate-like body 12 is MDF is that the plate-like body 12 can be mass-produced economically. Further, the strength per unit weight (specific strength) of the plate-like body 12 is about three times that of reinforced concrete, and it is excellent in fire resistance and has semi-permanent durability. Further, there is almost no expansion or contraction or dimensional deviation.

A heat insulating material 20 having an outer diameter slightly smaller than that of the plate-shaped body 12 is provided on the side surface of the stud 17 on the indoor side surface S12 of the plate-shaped body 12. The heat insulating material 20
In other words, it is partitioned by one stud 17. Insulation material 2
0 plays a main part when the wall panel 11 exhibits a heat insulating effect. The heat insulating material 20 is fitted in the installation space K formed in the frame 13. When the wall panel 11 is simply fitted into the installation space K, the indoor side surface S2 of the heat insulating material 20 is arranged at the same level as the indoor side surface of the pillar 14 and the horizontal member 15.

As the material of the heat insulating material 20, foamable polystyrene is used. The reason for choosing polystyrene is as follows. This is because polystyrene has fine and independent pores (discontinuous pores) inside and causes moderate plastic deformation when pressed.

The polystyrene, which is the raw material of the heat insulating material 20, contains a flame retardant. In this embodiment, aluminum hydroxide or a halogen compound is used as the flame retardant. This is to enhance the adhesiveness between the plate-shaped body 12 and the heat insulating material 20. Specific examples of the halogen-based compound include dibromopropyl phosphate, ethane tetrabromide, and bromochloropropyl phosphate. Incidentally, an acrylic resin-based adhesive is used as the adhesive.
The amount of flame retardant is 2% to 30% by weight of polystyrene.
It has become. The amount of flame retardant is 5% of polystyrene.
More preferably, the content is from 10% by weight to 10% by weight.

Further, the expansion ratio of the heat insulating material 20 is 30 to 7
It is set to 0 times. The reason for setting the magnification in this range is as follows. That is, if the expansion ratio is lower than 30 times,
Since the number of bubbles contained in the heat insulating material 20 is reduced, a large amount of polystyrene as a material is required. Therefore, the material cost of the heat insulating material 20 increases. On the other hand, if the expansion ratio is higher than 70 times, the thermal conductivity increases, the heat insulating property decreases, and the strength of the entire heat insulating material 20 decreases. In addition,
The expansion ratio of the heat insulating material 20 is more preferably 35 to 65 times.

As shown in FIGS. 1, 4 and 6, each heat insulating material 20 is composed of two upper components 21a and 21b and two lower components 22a and 22b, each of which is divided into upper and lower parts.
It is composed of Each upper component 21 facing each other
a, 21b and the respective lower component parts 22a, 22b are joined to each other. Each upper component 21a, 21b;
Contact surfaces 24, 25 with each lower component 22a, 22b
Are located in the middle part of each heat insulating material 20 in the vertical direction.

As shown in FIGS. 8 (a) and 8 (b), the contact surfaces 24, 2 of the respective components 21a, 21a, 22a, 22b
5 are formed stepwise so as to overlap each other. In the present embodiment, the contact surfaces 24 and 25 have two steps. The upper and lower contact surfaces 24 and 25 are formed with parallel portions 24a and 25a parallel to the indoor side surface S12 of the plate-like body 12. In addition, two vertical portions 24b and 25b are formed on the upper and lower contact surfaces 24 and 25 at locations located at both ends of the parallel portions 24a and 25a. Each vertical part 24
b and 25b are perpendicular to the indoor side surface S12 of the plate-shaped body 12. The lengths of the vertical portions 24b and 25b facing each other in the vertical direction are equal to each other.

As shown in FIGS. 1 to 3, two first notches 27 as thin portions are formed at both ends of the indoor side surface S2 of the heat insulating material 20. At the center of the indoor side surface S <b> 2 in the heat insulating material 20, two second notches 28 as thin portions are provided so as to sandwich the stud 17. The notches 27 and 28 are spaces for passing electric wiring connected to electric equipment of a wooden house. Each notch 2
7, 28 extend in the up-down direction and are parallel to each other. In this embodiment, the two notches 2
The depth of 7, 28 (D1, D2 shown in FIG. 2) is 35 mm
It has become. The depth of both notches 27 and 28 is 60 m
It is more preferable to set the length to m to 80 mm.

The first notch 27 is formed in a part of the portion where each heat insulating material 20 contacts the column 14. That is, the first notch 27 is formed along the longitudinal direction of the stud 17 except for the upper and lower ends of the heat insulating material 20. On the other hand, the second notch 28 is formed in a part of the portion where each heat insulating material 20 contacts the stud 17. That is, the second notch 28 is formed along the longitudinal direction of the stud 17 except for the upper and lower ends of the heat insulating material 20. The second notch 28 is set to the same length as the first notch 27.

In the heat insulating material 20, portions other than the first and second cutout portions 27 and 28 are thicker portions. In this thick portion, a grip portion 29 is formed in a region between the first cut portion 27 and the second cut portion 28. The width of the grip portion 29 is set to a length that can be gripped by an operator. Specifically, the width (W shown in FIG. 2) of the grip portion 29 is set to 13 cm to 17 cm. The width W of the gripper 29 is 13 cm to 15
cm is more preferable.

As shown in FIG. 1, FIG. 2 and FIG.
Pillows 31, 32 are formed at both upper and lower ends of the zero. The pillow portions 31 and 32 are thicker than the first and second cutout portions 27 and 28. Upper pillow part 3
1 and the lower pillow portion 32 have different vertical lengths. That is, the lower pillow portion 32 is lower than the upper pillow portion 31.
Is shorter in the vertical direction. Specifically, the length of the lower pillow portion with respect to the upper pillow portion is 2/3 or less (1
/ 5 or more to 2/3 or less). In the present embodiment, the length of the upper pillow portion 31 in the up-down direction (L1 shown in FIG. 1) is 24 cm to 30 cm, and the length of the lower pillow portion 32 (L2 shown in FIG. 1) is 12 cm to 21 cm. . Preferably, the length of the upper pillow part 31 is 23 cm or more.
27cm, length of lower pillow part 32 is 13cm ~ 16c
m is better.

As shown in FIGS. 1 and 7, the upper pillow portion 3
A plurality of construction adjustment markings 33 are provided on one indoor side surface. In the present embodiment, five construction adjustment markings 33 are provided. Each construction adjustment marking 33 is formed in a V-shaped cross section. Each construction adjustment marking 33 is linear and extends along the width direction (lateral direction) of each heat insulating material 20. The construction adjustment markings 33 are arranged at equal intervals in the vertical direction.
Interval of each marking 33 for construction adjustment (I shown in FIG. 7)
Is set to 3 cm. Construction adjustment marking 3
It is more preferable to set the interval of 3 to 3 cm to 6 cm.

The outdoor side surface S1 of the heat insulating material 20 is bonded to the indoor side surface S12 of the plate-like body 12 with an adhesive.
The outer edge of the heat insulating material 20 is a non-adhesion region (a portion other than the hatched portion in FIG. 9) R1, and a portion excluding the non-adhesion region R1 is an adhesion region (a portion indicated by the hatched portion in FIG. 9) R
It is 2. The non-bonding region R <b> 1 has a rectangular shape along the outer peripheral edge of the heat insulating material 20. Then, the bonding region R2
Is surrounded by the non-adhesion region R1. The construction adjustment marking 33 corresponds to the upper end of the non-adhesion region R1. In the present embodiment, the non-adhesion region R
1 has a width of 22 cm to 25 cm (W1 shown in FIG. 9).
cm. The width of the other portion (W2 shown in FIG. 9) is set to 4 cm to 8 cm.

As shown in FIG. 2 and FIG.
The dimension of the stud 17 in the direction orthogonal to 2 is the first
And the thickness of the heat insulating material 20 excluding the second cutout portions 27 and 28 is smaller than the thickness. In other words, the thickness of the heat insulating material 20 is larger than that of the stud 17. Specifically, the indoor side surface S2 of the heat insulating material 20 is
mm to 4 mm (B shown in FIG. 3C).

As shown in FIGS. 1 to 4, the upper and lower end surfaces S3 and S4 and the left and right end surfaces S5 and S6 of the heat insulating material 20 are each composed of a vertical surface 35 and a pair of inclined surfaces 36 and 37. I have. Each of the surfaces 35 to 37 is formed along the outer peripheral edge of the heat insulating material 20. Each vertical surface 35 is orthogonal to the indoor side surface S12 of the plate-shaped body 12, and is located at a substantially central portion of the end surfaces S5 and S6 of the heat insulating material 20. Slope 3
6, 37 are formed at both ends of the vertical surface 35.

As shown in FIGS. 3 (a) and 3 (b), in the end surfaces S4 to S6 of the heat insulating material 20, a portion corresponding to the vertical surface 35 is outwardly formed by the presence of the pair of inclined surfaces 36 and 37. Overhanging. Thereby, at both left and right end surfaces S5 and S6 of each heat insulating material 20, the first cutout portions 27 are formed.
A bulged portion 38 having a trapezoidal cross section is formed in a portion excluding. The bulging portion 38 is formed at substantially the center of the thickness of the heat insulating material 20. In addition, the bulging portion 38 projects more outward than the outdoor side surface S1 and the indoor side surface S2 of the heat insulating material 20. The bulge 38 extends along the outer peripheral edge of the heat insulating material 20. That is, the bulging portion 38
It covers the entire circumference of the heat insulating material 20. Further, the bulging portion 38
Is made of the same material as the heat insulating material 20 and
And are integrally formed. Therefore, the bulging portion 38 is elastically deformable.

As shown in FIG. 3B, the indoor inclined surface 36 and the outdoor inclined surface 37 are formed at the corners of the heat insulating material 20. And both inclined surfaces 3 with respect to the vertical surface 35
6 and 37, the inclination angles θ1 and θ2 are different, and the inclination angle θ1 of the indoor-side inclined surface 36 is larger than the inclination angle θ2 of the outdoor-side inclined surface 37. Specifically, the inclination angle θ of the indoor-side inclined surface 36 with respect to the vertical surface 35
1 is set to 30 ° to 60 °. It is more preferable that the inclination angle θ1 be 40 ° to 50 °. or,
The inclination angle θ2 of the outdoor-side inclined surface 37 with respect to the vertical surface 35
Is set to 5 ° to 25 °. This inclination angle θ2
Is more preferably set to 10 ° to 15 °.

As shown in FIG. 3C, the studs 17 of the upper and lower components 21a, 21b, 22a, 22b
The inclined surfaces 41a and 41b are formed at the locations in contact with. In the present embodiment, the inclination angle θ3 of each of the inclined surfaces 41a and 41b with respect to the side surface of the stud 17 is set to 5 ° to 25 °. This inclination angle θ3 is 10 ° to 15 °.
゜ is more preferable. And the inclined surface 41
a, 41b, a part of the stud 17 and a part of the plate-shaped body 12 in a space (hollow portion, hollow portion) 42
a and 42b are formed. In short, the voids 42a,
42b is formed by notching a part of the heat insulating material 20. Each of the gaps 42 a and 42 b is located near the plate-shaped body 12. Each of the gaps 42a and 42b is
Extend along the longitudinal direction of.

Next, a method of constructing the wall panel 11 of the present embodiment will be described. FIG. 5 shows a state before the wall panel 11 is assembled to the shaft set 13, and FIG. 6 shows a state where the wall panel 11 is assembled to the shaft set 13. As shown in the figure, the heat insulating material 20 of the wall panel 11 is fitted into the installation space K formed in the frame 13. At this time, the projection area of the indoor side surface S2 of the heat insulating material 20 is smaller than the projection area of the installation space K due to the presence of the bulging portion 38. Therefore, the indoor side of the heat insulating material 20 easily enters the installation space K. When the heat insulating material 20 is pushed in by a predetermined amount, the tip of the bulging portion 38 comes into contact with the inner surface of the shaft assembly 13. When the heat insulating material 20 is further pushed in, the bulging portion 3
The tip 8 is pressed against the inner surface of the shaft assembly 13 while its tip is slightly elastically deformed. When the plate-shaped body 12 comes into contact with the shaft assembly 13, the pushing of the heat insulating material 20 is regulated.

The mounting of the wall panel 11 inserted as described above is performed by driving a nail (not shown) or the like to the nailing mark 16. After the wall panel 11 is attached, the interior material of the wooden house (see FIG. 6)
3 is attached. Then, the exterior member 44 is attached to the frame 13 so that the plate-shaped body 12 cannot be seen from the outside of the wooden house.

Therefore, according to the present embodiment, the following effects can be obtained. (1) A bulging portion 38 extending along the outer edge of the heat insulating material 20 is formed at a substantially central portion of each of the end surfaces S3 to S6 of the heat insulating material 20. Thereby, the indoor side surface S of the heat insulating material 20
2 can be smaller than the projection area of the installation space K. Therefore, the heat insulating material 20 can be smoothly fitted into the frame 13. Along with that, insulation 2
Even if 0 is fitted in a slightly inclined state, a slight gap does not occur between the frame 13 and the heat insulating material 20. As a result, the bulging portion 38 can be brought into close contact with the inner side surface of the shaft assembly 13, and high airtightness can be secured.

(2) The bulging portion 38 is provided over the entire circumference of the heat insulating material 20. Therefore, the heat insulating material 20 can be more easily fitted into the installation space K. Moreover,
Since the outer end surface of the heat insulating material 20 can be brought into close contact with the frame 13 over the entire circumference, higher airtightness can be secured.

(3) The bulging portion 38 is made of the same material as the heat insulating material 20, that is, foamable polystyrene.
And it is formed integrally with the heat insulating material 20. For this reason,
When the heat insulating material 20 is formed, the bulging portion 38 can be formed at the same time. Therefore, the manufacturing process can be simplified,
The wall panel 11 can be manufactured easily and inexpensively.

(4) Since the bulging portion 38 is elastically deformable, the bulging portion 38 can be securely brought into close contact with the shaft assembly 13. Therefore, higher airtightness can be ensured.

(5) Since the heat insulating material 20 and the bulging portion 38 are made of a foamable material, the weight of the wall panel 11 can be reduced. And since the amount of material used can be reduced, the wall panel 11 can be manufactured more inexpensively.

The embodiment of the present invention may be modified as follows. The material for forming the heat insulating material 20 may be changed to a gypsum board, a pulp cement board, or an expandable polyurethane in addition to polystyrene. Further, the heat insulating material 20 can be, for example, a phenol resin, a silicone resin, a urea resin, or the like. Of course, these can be used in any combination.

In the above embodiment, the present invention is embodied in the wall panel 11 having the studs 17. Alternatively, as shown in FIG. 11, the stud 17 and the second notch 28 may be omitted, and the central portion of the heat insulating material 20 may be formed in a flat shape. When the shaft 13 is provided with the stud 17, the structure shown in FIG. 12 may be adopted. That is, the wall panel 11 is
A groove 50 that engages with the stud 17 provided on the shaft set 13 when attached to the shaft set 3 may be formed.

The material for forming the heat insulating material 20 and the bulging portion 38 may be changed to foamable urethane. The heat insulating material 20 and the bulging portion 38 are separately formed, and the heat insulating material 2
The bulging portion 38 may be attached to 0 using an adhesive. In this case, the materials for forming the heat insulating material 20 and the bulging portion 38 may be different.

The bulging portion 38 may be formed only on the upper and lower end surfaces S3 and S4 of the heat insulating material 20. The bulging portion 38
May be formed only on the left and right end surfaces S5 and S6 of the heat insulating material 20. Further, the bulging portion 38 may be formed in at least one of the end surfaces S3 to S6.

Next, in addition to the technical ideas described in the claims, the technical ideas grasped by the above-described embodiments are listed below together with their effects. (1) The wall panel according to any one of claims 1 to 3, wherein the bulging portion is elastically deformable. With this configuration, the bulging portion can be pressed against the shaft assembly.

(2) The wall panel according to any one of (1) to (3), wherein the heat insulating material is foamable. With this configuration, the weight of the heat insulating material can be reduced.

(3) Claims 1-3, (1),
The wall panel according to any one of (2), wherein the bulging portion is foamable. With this configuration, the weight of the bulging portion can be reduced.

(4) Claims 1-3, (1)-
The wall panel according to any one of (3), wherein the heat insulating material is polystyrene. With this configuration, the material cost of the heat insulating material can be reduced.

(5) Claims 1-3, (1)-
(4) The wall panel according to any one of (4), wherein the bulge portion is made of polystyrene. With this configuration, the material cost of the bulging portion can be reduced.

(6) Claims 1-3, (1)-
(5) The wall panel according to (5), wherein the bulging portion has a trapezoidal cross section. (7) In a wall panel which is arranged between a frame of a wooden house and a heat insulating material is provided on a plate-like body, a bulge extending along a vertical direction of the heat insulating material is provided at a substantially central portion between left and right end surfaces of the heat insulating material. Wall panel characterized by having a part.

(8) In a wall panel which is arranged between a frame of a wooden house and a heat insulating material is provided on a plate-like body, the heat insulating material is disposed substantially at the center of the upper and lower end faces along the left and right direction of the heat insulating material. A wall panel provided with a bulging portion that extends.

[0048]

As described above in detail, according to the first aspect of the present invention, the heat insulating material can be smoothly fitted into the frame. At the same time, the tip of the bulging portion can be brought into close contact with the shaft assembly, so that high airtightness can be ensured.

According to the second aspect of the present invention, the heat insulating material can be more easily fitted into the frame, and
Even higher airtightness can be secured. According to the third aspect of the present invention, since the manufacturing process can be simplified, the wall panel can be manufactured easily and inexpensively.

[Brief description of the drawings]

FIG. 1 is a front view in which a wall panel is assembled to a shaft assembly in one embodiment.

FIG. 2 is a sectional view taken along line 2-2 in FIG.

FIG. 3A is a sectional view taken along line 3a-3a in FIG. 1;
(B) is a sectional view taken along line 3b-3b in FIG. 1, and (c) is a sectional view in FIG.
3c-3c sectional view in FIG.

FIG. 4 is an exploded perspective view showing a shaft assembly and a wall panel.

FIG. 5 is a cross-sectional view before the wall panel is assembled to the shaft assembly.

FIG. 6 is a cross-sectional view after the wall panel is assembled to the shaft assembly.

FIG. 7 is a sectional view showing an upper pillow part.

8A is an exploded front view showing an upper component member and a lower component member, and FIG. 8B is a side view of FIG.

FIG. 9 is a front view showing only a wall panel.

FIG. 10 is a rear view of the wall panel.

FIG. 11 is a front view showing a wall panel in which a stud is omitted in another embodiment.

FIG. 12 is a front view showing a different type of wall panel from FIG. 11;

[Explanation of symbols]

13: Frame, 12: Plate, 20: Insulating material, S3, S4
... Upper and lower end faces (outer end faces), S5, S6.

 ────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tatsuya Abe 5-1-1, Nitta-cho, Takahama-shi, Aichi F-term in the Kinuura Plant of Biden Co., Ltd. (Reference) 2E001 DD01 DD02 DE01 EA09 FA04 GA12 GA17 GA42 GA82 HC13 HD03 HD09 JA09 JD02 KA02 LA04 LA12 2E002 EA01 EA08 EB12 FA03 FB07 FB10 FB14 HA02 HB01 HB16 JA01 JA02 JB01 JB16 LA01 LB07 LB13 MA05 MA33 MA47

Claims (3)

[Claims] 1. A wall panel disposed between a frame of a wooden house and provided with a heat insulating material on a plate-like body, wherein the heat insulating material is formed at a substantially central portion of an outer end surface thereof along an outer edge of the heat insulating material. A wall panel having a bulging portion. 2. The wall panel according to claim 1, wherein the bulging portion is provided over the entire circumference of the heat insulating material. 3. The wall panel according to claim 1, wherein the bulging portion is made of the same material as the heat insulating material, and is formed integrally with the heat insulating material.