JPH04316986A - Checker brick and constructing method thereof - Google Patents

Abstract

PURPOSE:To obtain a checker brick easy in manufacturing and handling in transportation, storage or the like and having a connecting part provided with a sufficient strength. CONSTITUTION:The whole configuration of a checker brick is a rectangular parallelepiped substantially and a pair of connecting projections 21, 22, projected into mutually opposing directions orthogonally to the long axis substantially, are formed on a first end 3. A connecting recess 31, recessed into a direction along said long axis, is formed on the second end of the checker brick. When two pieces of the checker bricks 1 are arranged so that the end faces 9 of the first ends 2 are abutted against to each other, the connecting recess 31 can be engaged with one of the pair of projections formed by the connecting projections 21, 22.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to checker bricks used to construct heat storage chambers in industrial furnaces and the like, and a method for constructing the same.

0002

[Prior Art] A general rectangular parallelepiped checker brick (gitter) has a simple shape and a reasonable size, so it is not only easy to manufacture, but also has the advantage of being easy to handle during transportation and construction. However, on the other hand, there are concerns about stability when constructed. Therefore, in order to improve the stability during construction, for example, Japanese Patent Publication No. 55-45385, Japanese Patent Application Laid-Open No. 57-161487, Japanese Patent Application Laid-Open No. 57-1614
As disclosed in Japanese Patent Publication No. 88 and Japanese Patent Publication No. 1-43238, checker bricks having a unique shape have been proposed.

The checker brick disclosed in Japanese Patent Publication No. 55-45385 has three or four arms radially extending from a central hub portion. When constructing these checker bricks, first place multiple checker bricks on the base in the same direction with their arm ends facing each other.
Constitutes the first layer. Next, the second layer is constructed by arranging the checker bricks so that the central hub portion is located above the location where the ends of each arm of the first layer are butted against each other. Repeat this for layers above the third layer.

[0004] The checker brick disclosed in JP-A-57-161487 has a cylindrical body with a square or rectangular cross section, and cuts are made on both sides of the ridgeline within a range of 1/2 or less of the height of each corner. It contains The cylindrical body may have a cross section that is more polygonal than quadrangular. When constructing these checker bricks, first place multiple checker bricks in the same direction on the base with the notches facing upwards, and
Configure layers. Next, place the second layer of checker bricks on top of the points where the corners of the four adjacent checker bricks of the first layer are butted together, with the notches facing upward, so as to straddle these checker bricks. , each corner of the second layer of checker bricks is fitted into a notch in the first layer of checker bricks, respectively. Repeat this for layers above the third layer. Note that the second layer of checker bricks may be placed with the notches facing downward.

[0005] The checker brick disclosed in JP-A-57-161488 has a cylindrical body with a regular hexagonal cross section, and every other six sides of one end face have a cylindrical shape extending in the direction of the central axis of the cylindrical body. Along the cylindrical body, a protrusion is provided which has approximately the same thickness as the side portion and has a height equal to or lower than the height of the cylindrical body. The cross section of the cylinder may be a parallelepiped. When constructing this checker brick, first, a first parallel line group drawn at the same interval, and a first parallel line group drawn at the same interval as the first parallel line group and for the first parallel line group. 60° and 120 respectively
Consider second and third groups of parallel lines that form a degree angle and intersect at the same point, and arrange each checker brick in the same direction so that the center is located at each intersection of these parallel lines to form the first layer. do. Next, the sides that do not have the protrusions are connected to each other by 60°.
A second layer of checker bricks is placed between three checker bricks of the first layer facing each other at an angle of .degree., with their protrusions aligned in the same direction. At this time, the side portions of the second layer of checker bricks that do not have protrusions are brought into contact with the side portions that do not have protrusions of the three checker bricks of the first layer. Repeat this for layers above the third layer. When placing the second layer of checker bricks, the protrusions may be directed upward or downward.

The checker brick disclosed in Japanese Patent Publication No. 1-43238 is a checker brick formed into a rectangular shape with fitting protrusions formed at both left and right ends. The fitting protrusion has a planar shape that is at an acute angle from one side of the checker brick inward, and an end face that is approximately perpendicular to the end where the width of this end face is approximately 1/2 the width of the checker brick. consisting of an engaging surface provided inwardly with substantially the same width as the end surface, and a stepped portion provided approximately at right angles to the other side between the base of the engaging surface and the other side of the checker brick. It has been done. When constructing these checker bricks, first, butt the fitting protrusions at one end of the four checker bricks together, and insert the fitting protrusion of one adjacent one into the fitting protrusion of the other from above and below. Connect the four checker bricks in a cross shape by fitting them together. Next, the fitting protrusions on the opposite side of these cross-shaped checker bricks are also fitted and connected to other checker bricks in the same manner. In this way, a plurality of checker bricks are arranged in a grid pattern to form the first layer. The checker bricks of the second layer are placed directly on top of each checker brick of the first layer in the same direction to form a grid-like second layer. Repeat this for layers above the third layer.

[0007]

[Problem to be solved by the invention] The above-mentioned Special Publication Publication No. 55-45
The checker brick described in Publication No. 385 is difficult to manufacture because it has a central hub portion and arms extending radially from the central hub portion, and is difficult to handle during transportation, storage, etc. due to its bulk and weight. The problem is that it is inconvenient.

[0008] The checker bricks described in JP-A-57-161487 and JP-A-57-161488 have a cylindrical body with a square, rectangular or regular hexagonal cross section. 55-45385
There is a problem similar to that of the checker brick described in the publication. Furthermore, during construction, each checker brick making up the first layer must be placed at a predetermined interval so that the checker bricks of the second layer fit properly, making the construction work difficult. There is also the problem.

[0009] The checker brick disclosed in Japanese Patent Publication No. 1-43238 can have a volume and weight close to that of Gitter, so that the inconvenience of handling during transportation, storage, etc. is considerably eliminated. However, not only is the shape of the fitting protrusion complex, but also the fitting protrusion has sharp corners, which makes it difficult to manufacture, and there are problems in that the fitting protrusion is easily chipped by impact. Furthermore, when connecting checker bricks, it is necessary to move the fitting protrusion of one checker brick from above to below and insert it between the engagement surface and step of the other checker brick. There is also the problem that the construction work is complicated, as sufficient care must be taken to ensure that the sharp corners are not chipped.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a checker brick that is easy to manufacture, easy to handle during transportation, storage, etc., and has sufficient strength at the connecting portions.

Another object of the present invention is to provide a method for constructing checker bricks that facilitates the construction work and provides excellent stability after construction.

0012

[Means for Solving the Problems] The checker brick of the present invention has a substantially rectangular parallelepiped shape, and has projecting portions at the first end in the longitudinal direction in opposite directions substantially perpendicular to the longitudinal axis. It has a pair of connecting protrusions and a second connecting convex portion in the longitudinal direction.
The end portion has a connecting recess recessed in the direction along the long axis, and the connecting recess is formed when the two checker bricks are arranged with their end surfaces on the first end side facing each other. It is characterized by being able to fit into one of the pair of protrusions formed by the connecting convex portions.

The method for constructing checker bricks of the present invention is the method for constructing checker bricks described above, in which the first and second checker bricks are arranged with their first end faces facing each other, while the third and second checker bricks are arranged with their first end faces facing each other. A fourth checker brick is arranged on each side of the first and second checker bricks so as to be perpendicular to the first and second checker bricks, and is formed by a connecting convex portion of the first and second checker bricks. It is characterized in that the coupling recesses of the third and fourth checker bricks are fitted into the pair of projections, respectively.

[0014]

[Operation] The checker brick of the present invention has a generally rectangular shape as a whole, and the first
It is only necessary to form a pair of connecting convex portions at the ends and a connecting recess at the second end, and there is no need to form the plurality of arms radially or cylindrically. Therefore, it can be easily manufactured, and it is also easy to handle during transportation, storage, etc.

[0015] Also, the connecting recess of the checker brick is 2
Since it is only necessary that the checker bricks can be fitted into one of the pair of protrusions formed by the pair of coupling convex parts when the first end side end surfaces of the checker bricks are arranged with their end faces facing each other. Also, there is no need to form an acute angle part or a thin part in the connecting convex part. Therefore, the strength of the connecting portion of the checker bricks can be increased.

In the method of constructing checker bricks according to the present invention, when connecting checker bricks, after abutting the end surfaces of two checker bricks on the first end side, another checker brick is connected perpendicularly to both checker bricks. Two checker bricks may be placed on each side, and their connecting recesses may be fitted into the protrusions formed by the connecting convex portions of the matched checker bricks. Therefore, there is no need to arrange the checker bricks with predetermined gaps or to work particularly carefully so as not to damage the connecting parts, which simplifies the construction work.

Furthermore, when the checker bricks are connected in a lattice shape, the first end with the connecting convex portion and the second end with the connecting concave portion are locked to each other, and the checker bricks are connected along the surface including the lattice. cannot move in either direction. During construction, the brick layers thus formed are stacked one on top of the other, resulting in excellent stability after construction.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. Note that this invention is not limited to this.

(Structure) FIG. 1 is a perspective view showing a first embodiment of the checker brick of the present invention, FIG. 2(a) is a plan view thereof, FIG. 2(b) is a front view thereof, and FIG. 2(c) is its side view.

The checker brick 1 has a generally rectangular parallelepiped shape as a whole. The upper surface 5 and the lower surface 6 are both parallel to the long axis thereof, and the end surface 9 on the first end 2 side and the end surface 10 on the second end 3 side are both perpendicular to the long axis. ing. Therefore, both end surfaces 9 and 10 are perpendicular to the upper surface 5 and the lower surface 6. The side surfaces 7 and 8 are inclined with respect to the long axis of the checker brick 1 except for the both ends 7a, 7b, 8a, and 8b, and the thickness of the checker brick 1 (the distance between the both sides 7 and 8) is , as clearly shown in FIG. 2(a), gradually decreases in size from the second end 3 to the first end 2. Ends 7a, 8a, 7b, 8b of sides 7, 8
are both planes parallel to the long axis. Both side surfaces 7, 8 are perpendicular to the upper surface 5 and the lower surface 6 over their entire length.

A protrusion 11 for preventing displacement is formed approximately at the center of the upper surface 5 in the longitudinal direction, and has a trapezoidal cross section in the vertical direction along the longitudinal direction. Similarly, a recess 12 for preventing displacement having the same cross-sectional shape as the protrusion 11 is formed approximately in the center of the lower surface 6 in the longitudinal direction. Protrusion 11
The center of the depression 12 in the longitudinal direction is located at a distance from the end surface 9 of (E+D/2), where E is the distance from the end surface 10 (see FIG. 2(b)). Here D is the minimum thickness of the checker brick 1, i.e. the end 7 of the sides 7, 8
This is the distance between a and 8a. The protrusion 11 and the depression 12 are
When two checker bricks 1 are stacked one on top of the other with their end faces 9 and 10 aligned, the recess 12 of the upper checker brick 1 fits into the protrusion 11 of the lower checker brick 1, and both checker bricks 1
It acts to prevent relative movement in the longitudinal direction.

Since the projections 11 and depressions 12 have their centers located at positions that satisfy the relationship E: (E+D/2) in the longitudinal direction of the checker bricks 1, when the upper and lower checker bricks 1 are placed in opposite directions, That is, even if the end surface 9 of the upper checker brick 1 is placed on the end surface 10 side of the lower checker brick 1, they will fit together in the same way as in the above case, and the checker brick 1 will be prevented from moving relative to the longitudinal direction. be able to.

First end 2 of the checker brick 1 in the longitudinal direction
A pair of connecting convex portions 21 and 22 are formed on the connecting convex portions 21 and 22 which protrude in the horizontal direction orthogonal to the long axis thereof. The connecting protrusions 21 and 22 have exactly the same shape except that they face oppositely to each other. That is, the connecting convex portions 21 and 22
Each extends perpendicularly to the long axis from the lower surface 6 to the upper surface 5, and its horizontal cross section is the same trapezoid over the entire length.

The end face 9 on the first end side is a rectangular plane and reaches the outer edges of the connecting projections 21 and 22. The end surface 9 on the first end side also connects to the end 7a of the side surface 7 via the first engagement surface 23 and second engagement surface 25 of the coupling convex portion 21.
On the other hand, it is connected to the end 8a of the side surface 8 via the first engagement surface 24 and the second engagement surface 26 of the convex portion 22. The first engaging surfaces 23 and 24 are planes parallel to the long axis of the checker brick 1, and the second engaging surfaces 25 and 26 are planes inclined to the long axis of the checker brick 1.

[0025] The first engagement surface 23 and the second engagement surface 2 of the convex portion 21
5 is the angle α between the first engagement surface 24 of the convex portion 22 and the second engagement surface 24 of the convex portion 22.
It is equal to the angle β formed with the engagement surface 26, and both are obtuse angles (approximately 100° here). The angle between the second engagement surface 25 and the end 7a of the side surface 7 is equal to the angle α between the second engagement surface 25 and the first engagement surface 23. Similarly, the second engagement surface 26
The angle formed by the end portion 8a of the side surface 8 is equal to the angle β formed between the second engagement surface 26 and the first engagement surface 24.

[0026] The second end portion 2 is located on the opposite side in the longitudinal direction of the first end portion 2.
A connecting recess 31 is formed in the end 3 and is recessed toward the first end 2 along its long axis. This connection recess 31 is
It is located at the center of the end surface 10 and extends from the lower surface 6 to the upper surface 5. Therefore, the second end surface 10 has the connecting recess 3
It is divided into two by 1. The horizontal cross section of the connecting recess 31 is a trapezoid that is symmetrical with respect to the long axis of the checker brick 1.

The two end surfaces 10 are both rectangular planes and extend from the outer edges of the ends 7b, 8b of the side surfaces 7, 8 to the outer edges of the second engagement surface 33 and the third engagement surface 34. There is. Further, they are connected to each other via a second engagement surface 33, a first engagement surface 32, and a third engagement surface 34. First engagement surface 32
is a plane perpendicular to the long axis of the checker brick, and the second engaging surface 33 and the third engaging surface 34 are planes inclined with respect to the long axis.

The angle γ between the first engagement surface 32 and the second engagement surface 33 is equal to the angle δ between the first engagement surface 32 and the third engagement surface 34, and both are obtuse angles. Both angles γ and δ are
The angle α between the second engaging surface 25 and the first engaging surface 23 of the connecting convex portion 21, and the angle β between the second engaging surface 26 of the connecting convex portion 22 and the end 8a of the side surface 8. be equivalent to.

As shown in FIG. 2(a), the connecting convex portion 21
, 22 (the length in the longitudinal direction of the first engaging surfaces 23 and 24) t1 is the width T1 of the bottom of the coupling recess 31 (the first
It is approximately equal to 1/2 of the length of the engaging surface 32 in the direction perpendicular to the long axis. In addition, the width of the base of the connecting convex portions 21 and 22 (the length in the long axis direction at the positions of the ends 7a and 8a of the side surfaces 7 and 8)
t2 is approximately equal to 1/2 of the width T2 (the distance between the inner edges of the second engagement surface 33 and the third engagement surface 34) of the tip of the coupling recess 31.

When two checker bricks 1 are arranged in a straight line with the end surfaces 9 of the first ends 2 facing each other, as shown in FIG. A pair of protrusions are formed on each side. This pair of protrusions are
It has a shape and size that perfectly fits into the coupling recess 31. Therefore, when another checker brick 1 is arranged so as to be orthogonal to both checker bricks 1 and its connecting recess 31 butts against either of the pair of protrusions, the connecting recess 31 fits into the protrusion. match. In this way, two butted checker bricks 1 can be connected. Similarly, by abutting and fitting another checker brick 1 from the opposite side, four checker bricks 1 can be connected in a cross shape as shown in FIG.

In FIG. 3, the first engaging surfaces 23 and 24 of the connecting convex portions 21 and 22 are both connected to the first engaging surfaces 23 and 24 of the connecting concave portion 31.
The second engaging surfaces 25 and 26 of the connecting convex portions 21 and 22 contact the second engaging surface 33 and the second engaging surface 34 of the connecting recess 31, respectively. The end surface 10 is the side surface 7
, 8 contact the ends 7a, 8a.

[0032] In this embodiment, the connecting convex portion 21,
22 (the thickness of the first end 2) is the distance C between the ends 7b, 8b of the side surfaces 7, 8 (the second
The thickness of the end portion 3) is made equal to A.

(Construction Method) Next, a method of constructing a heat storage chamber for an industrial furnace using the checker brick 1 having the above structure will be explained. First, as shown in FIG. 4, first and second checker bricks 1a and 1b are placed on a foundation with the projections 11 for displacement facing upward and their end surfaces 9 butted against each other. At this time, both checker bricks 1a and 1b are aligned on a straight line.

Next, the third and fourth checker bricks 1
c, 1d, the first and second checker bricks 1a, 1
Both checker bricks 1a are perpendicular to b.
, 1b. Then, the coupling recesses 31 of the third and fourth checker bricks 1c and 1d are fitted into the pair of protrusions formed by the coupling protrusions 21 and 22 of the first and second checker bricks 1a and 1b, respectively. let

In this way, among the four checker bricks 1a, 1b, 1c, and 1d arranged in a cross shape, the first and second checker bricks 1a and 1b are connected to each other. In this state, the third and fourth checker bricks 1c,
1d can move in the direction away from the first and second checker bricks 1a and 1b, but the connecting convex portions 21 and 22 of the third and fourth checker bricks 1c and 1d cannot be connected to other checker bricks. Since the recess 31 is fitted,
As a whole, movement of each checker brick 1a, 1b, 1c, 1d is prevented.

For example, in FIG. 4, the end surface 9 of the fifth checker brick 1e is brought into contact with the end surface 9 of the fourth checker brick 1d, and the sixth and fifth checker bricks are attached to the pair of projections formed by the connecting projections 21 and 22. If the connection recesses 31 of the seventh checker bricks 1f and 1g are fitted,
Movement of the fourth checker brick 1d is prevented by the sixth and seventh checker bricks 1f and 1g.

Thereafter, when the connecting protrusions 21, 22 and the connecting recess 31 are fitted in the same manner, the first brick layer connected in a lattice shape by each checker brick is formed as shown in FIG. It is formed. A plurality of square cavities are formed in the first brick layer by each checker brick. Checker bricks are placed on top of the first brick layer in the same manner as above to form a second brick layer connected in a lattice pattern and a third or higher layer. A heat storage chamber with a large number of cavities is constructed.

When forming the second brick layer on the first brick layer, the protrusions 11 for preventing displacement are directed upward, and the first brick layer is
The checker bricks of the brick layer are placed in the opposite direction, that is, with the first end 2 and the second end 3 aligned. In this case, the arrangement of the checker bricks 1 in each brick layer is the same, but the arrangement of the odd-numbered brick layers is shifted by one column from the arrangement of the even-numbered brick layers. but,
It is also possible to place the first end portions 2 in alignment with each other.

In the constructed heat storage chamber, the connection between each brick layer is strong, and the protrusions 11 for preventing displacement are formed in the depressions 1.
2, and the checker bricks 1 of the first brick layer and the checker bricks 1 of the second brick layer are not likely to be misaligned along any of the sides of the square, resulting in an extremely robust structure. Become.

The checker brick 1 is made of a known material. Examples of the material include silica, alumina,
Examples include zircon, magnesia, and chromium oxide alone or in mixtures thereof.

(Other Embodiments) FIG. 5 shows a second embodiment of the present invention. In the checker brick 1 of the second embodiment, the first
The connecting protrusions 21 and 22 of the end portion 2 have exactly the same structure as the connecting protrusions 21 and 22 of the first embodiment. However, the second
The configuration of the end portion 3 and the configuration of the intermediate portion 4 are different.

In the checker brick 1 of the second embodiment, the central parts of the side surfaces 7 and 8 are parallel to the long axis, and the first end 2 side thereof is directly connected to the second engaging surfaces 25 and 26. . Second
The end side is connected to the checker brick 1 via the inclined surfaces 7c and 8c.
The ends 7b and 8b are connected to each other parallel to the long axis. The distance C between the first engaging surfaces 23 and 24 of the connecting projections 21 and 22 (thickness of the first end 2) is the distance C between the ends 7b and 8b of the side surfaces 7 and 8 (the thickness of the second end 2). 3) is equal to A and is larger than the width B of the intermediate portion 4.

The work of connecting the checker bricks 1 of the second embodiment is exactly the same as that of the first embodiment. The configuration of the connecting portion is as shown in FIG. 5(b).

FIG. 6 shows a third embodiment of the invention. In the checker brick 1 of the third embodiment, the connecting convex portions 21 and 22 of the first end portion 2 have the same configuration as the connecting convex portions 21 and 22 of the first example, but the configuration of the second end portion 3 The structure of the intermediate section 4 is different from that of the first embodiment.

The side surfaces 7 and 8 are parallel to the long axis except for the ends 7d and 8d, and the first end 2 side is connected to the ends 7a and 8a via the inclined surfaces 7d and 8d. The second end side reaches the end surface 10 while maintaining the thickness of the intermediate portion 4. 1st
Width C of end portion 2, width A of second end portion 3, and width B of intermediate portion 4
are both equal.

The work of connecting the checker bricks 1 of the third embodiment is exactly the same as that of the first embodiment. The configuration of the connecting portion is as shown in FIG. 6(b).

FIG. 7 shows a fourth embodiment of the invention. The checker brick 1 of the fourth embodiment has almost the same configuration as the first embodiment, except that the width A of the second end 3 is larger than the width C of the first end 2. . The work of connecting the checker bricks 1 of the fourth embodiment is exactly the same as that of the first embodiment.

As described above, the shapes of the first end 2, second end 3, and intermediate portion 4 can be changed in various ways. The point is that when two checker bricks 1 are arranged in a straight line with the end surfaces 9 of the first ends 2 facing each other, the connecting convex portions 21, 2
The connecting recess 31 at the second end of another checker brick 1 can be fitted into one of the pair of protrusions formed by 2, and furthermore, the two checker bricks 1 that are butted together are connected by this fitting. It is sufficient that they cannot be separated in the long axis direction.

[0049] It is preferable that the checker brick of the present invention has approximately the same size and weight as the conventional gitter. This makes the unit weight and volume smaller than the conventional checker bricks with radial arms or square columnar checker bricks, making transportation easier and requiring less storage space. Moreover, homogeneous physical properties can be obtained.

An example is as follows.

Unit weight (kg
/pcs) Volume occupied by a single unit (cc/pcs)
Conventional product 7.4
6000
Invention 3.8
1500

0
052]

[Effects of the Invention] The checker brick of the present invention is easy to manufacture, easy to handle during transportation, storage, etc., and has sufficient strength in the connecting portions. Further, the method for constructing checker bricks of the present invention allows for easy construction work and is excellent in stability after construction.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing a first embodiment of a checker brick according to the present invention.

[Figure 2] (a) is a plan view of the checker brick in Figure 1, (b)
) is its front view, and (c) is its side view.

FIG. 3 is a partially enlarged plan view of a connecting portion of the checker bricks in FIG. 1;

FIG. 4 is a plan view of one brick layer when constructing a heat storage chamber using the checker bricks of FIG. 1;

FIG. 5 shows a second embodiment of the checker brick of the present invention, in which (a) is a plan view thereof, and (b) is a partially enlarged plan view of a connecting portion of the checker brick.

FIG. 6 shows a third embodiment of the checker brick of the present invention, in which (a) is a plan view thereof, and (b) is a partially enlarged plan view of a connecting portion of the checker brick.

FIG. 7 is a plan view showing a fourth embodiment of the checker brick of the present invention.

[Explanation of symbols]

1, 1a, 1b, 1c, 1d, 1e, 1f, 1g Checker brick 2 First end 3 Second end 4 Middle part 5 Upper surface 6 Lower surface 7 Side surface 7a, 7b, 7c, 7d Side end portion 8 Side surface 8a , 8b, 8c, 8d Side end 9 End face 10 of the first end End face 21, 22 of the second end Convex portions 23, 24 for connection 24 First engagement surface 25, 26 Second engagement surface 31 For connection Recess 32 First engagement surface 33 Second engagement surface 34 Third engagement surface

Claims (2)

[Claims] Claim 1: The parallelepiped has a substantially rectangular parallelepiped shape, and has a pair of connecting convex portions protruding in opposite directions substantially perpendicular to the long axis at the first end in the long axis direction, and has a long parallelepiped shape. The second end in the axial direction has a connecting recess recessed in the direction along the long axis, and the connecting recess is formed by butting the end surfaces of the two checker bricks on the first end side. A checker brick characterized in that it can be fitted into one of a pair of protrusions formed by the connecting convex portions when the checker bricks are arranged. 2. The method for constructing checker bricks according to claim 1, wherein the first and second checker bricks are arranged with their first end faces facing each other, while the third and fourth checker bricks are arranged with their first end faces facing each other. checker bricks are arranged on each side of the first and second checker bricks so as to be perpendicular to the first and second checker bricks, and a pair of projections are formed by connecting projections of the first and second checker bricks; A method for constructing checker bricks, comprising fitting the connecting recesses of the third and fourth checker bricks, respectively.