JP7183102B2 - building board - Google Patents

Description

Article 30, Paragraph 2 of the Patent Act applies Nichiha Co., Ltd. held its own exhibition on November 9, 2018

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a board material for construction, that is, a building board that can be used for exterior finishing and interior finishing of buildings.

BACKGROUND ART Building boards having a predetermined design surface, such as ceramic siding boards and metal siding boards, are sometimes used as building board materials for constructing outer walls and inner walls of buildings. When constructing a wall using building boards, a plurality of building boards are spliced together vertically and horizontally. Design surfaces of such building boards include a design surface with a brick-like pattern, a design surface with a tile-like pattern, a design surface with a masonry-like pattern, and the like. Techniques related to such building boards are described, for example, in Patent Documents 1 and 2 below.

JP 2012-107470 A JP 2015-140607 A

Building boards such as those described above for constructing walls are required to be inconspicuous in joint locations and misalignment when a plurality of boards are joined together.

The present invention was conceived under such circumstances, and its object is to provide a building structure suitable for suppressing the conspicuousness of seamed portions and their deviations in the construction state in which a plurality of sheets are seamed. It is to provide a board.

The building board provided by the present invention has an outline shape defined by a pair of first edges extending in a first direction and a pair of second edges extending in a second direction intersecting the first direction, and has a design surface. have The first and second directions are preferably orthogonal.

The building board has, on its design surface, a plurality of first joint grooves, a plurality of second joint grooves, and a design convex portion whose contour shape is defined by these joint grooves. The first joint groove and the second joint groove are pseudo joint grooves formed on the design surface of the building board.

Each first joint groove is a through joint extending in the first direction, and a single joint extending over the plurality of building boards in a state in which the plurality of building boards are continuously joined via their second edges. It is arranged so as to form a part of the through joint. The plurality of first rifts include at least one shallow rift that includes a first shallow area and a second shallow rift that is deeper than this, and at least one deep rift that is deeper than the shallow rift. .

Each second joint groove extends in the second direction and connects with at least one first joint groove. The plurality of second joint grooves on the design surface may include second joint grooves extending in the second direction from one first joint groove to another first joint groove. Further, the plurality of second joint grooves may include second joint grooves intersecting at least one first joint groove from one first joint groove to another first joint groove.

When constructing a wall using the building board having the above structure, a plurality of building boards are spliced together in the vertical direction (longitudinal direction) and the horizontal direction (horizontal direction).

As described above, a plurality of first joint grooves are formed as through joints on the design surface of the building board, and the plurality of first joint grooves include shallow and deep grooves having different groove depths. is included (the plurality of first joint grooves do not all have a common groove depth). In a state in which two of the building boards are joined, for example, in the vertical direction via their first edges, a joint groove is formed at the joint portion (first joint portion) as a through joint extending in the first direction. When formed, the joint groove resembles each first joint groove (through joint) on the design surface of the building board.

The joint groove as a through joint at the first joint location and the plurality of first joint grooves as through joints on the design surface are spaced apart from each other in the second direction and arranged in parallel, and have a common groove depth. not Therefore, when a joint groove is formed as a through joint at the first joint location, the joint groove is suppressed from being conspicuous. That is, the plurality of first joint grooves on the design surface of the building board suppress the conspicuousness of the joint grooves when the joint grooves are formed at the first joint locations, and furthermore, the first joint locations themselves. conspicuous.

In addition, in a state in which two of the building boards are joined, for example, in the left-right direction via their second edges, a joint groove extending in the second direction is formed at the joining point (second joining point). If so, the joint groove resembles each second joint groove also extending in the second direction in the design plane. Therefore, the plurality of second joint grooves on the design surface of the building board suppress the conspicuousness of the joint grooves when the joint grooves are formed at the second joints, and furthermore, the second joints themselves. conspicuous.

In addition, the first joint groove of the present building board includes a shallow joint groove having a depth variation, as described above. The depth change or step in the shallow joint ditch resembles the step formed when there is a thickness deviation between the adjacent building boards at the second seam described above. Moreover, in the plurality of first joint grooves, the depth change or level difference in the shallow joint grooves, which are shallower than the deep joint grooves, is conspicuous. Such a change in the depth of the shallow ditch suppresses conspicuousness of a step formed when there is a deviation in the thickness direction between adjacent building boards at the second joint location.

Furthermore, when a gap in the second direction occurs between the adjacent building boards at the above-mentioned second joint location, and as a result, a step or a positional gap in the second direction occurs between the design surfaces of the adjacent building boards. The depth change or step in the joint groove suppresses the step or positional deviation from becoming conspicuous. Further, even if there is no deviation in the second direction D2 between the adjacent building boards, the depth change or level difference in the shallow graben disperses the attention that should be focused on the second joint location, and the second joint location becomes conspicuous. suppress

As described above, the building board of the present invention has the effect of suppressing conspicuousness of seamed portions and misalignment thereof when a plurality of building boards are joined together.

Preferably, in the present building board, boundary lines formed by groove bottoms of at least one of the first joint grooves that are adjacent to each other through one of the second joint grooves and face in common are displaced from each other in the second direction. It has a pair of design protrusions. Such a misalignment shape between the design convex portions adjacent via the second joint groove is a problem in the case where a deviation in the second direction occurs between the adjacent building boards at the above-mentioned second joint location. It resembles the shape of the positional deviation between two design convex portions adjacent to each other through the joint groove extending in the second direction at some points, and suppresses the conspicuousness of the shape.

Preferably, the plurality of design protrusions include design protrusions having linear joints extending in the second direction. In the present invention, the linear joint is a linear separation that creates discontinuity in the first direction in the appearance of the design convex portion. It is a partition that creates a step in the thickness direction of the building board. Such a linear joint as a partition is similar to a discontinuous shape in the first direction, such as a step formed when there is a deviation in the thickness direction between adjacent building boards at the second joint location. , thus suppressing its prominence.

Preferably, the design convex portion having a linear joint has two partial convex portions adjacent to each other via the linear joint, and the two partial convex portions are at least one of the commonly facing first joint grooves are displaced from each other in the second direction. Such a misaligned shape between adjacent partial protrusions via a linear joint is a joint in the second joint when a misalignment in the second direction occurs between the adjacent building boards at the above-mentioned second joint. (extending in the second direction) resembles the shape of the misalignment between two design convex portions adjacent to each other, and suppresses the conspicuousness of the misalignment.

Preferably, each first joint groove has groove bottoms having the same length in the second direction at one end and the other end in the first direction. In such a configuration, the first joint grooves of one building board and the first joint grooves of the other building board are combined to form a continuous through joint at the above-mentioned second joint location. , thus suppressing conspicuousness of the second seam.

Preferably, the plurality of first rift trenches comprise a first shallow region, a second shallow region deeper than this, a third shallow region deeper than the first shallow region and shallower than the second shallow region, contains at least one shallow rift containing Such a configuration suppresses conspicuousness of a step formed when there is a deviation in the thickness direction between adjacent building boards at the above-described second joint location.

Preferably, the plurality of first rifts includes at least one deep rift including a first deep rift region and a deeper second rift region. Such a configuration suppresses conspicuousness of a step formed when there is a deviation in the thickness direction between adjacent building boards at the above-described second joint location.

1 is a plan view of a building board according to one embodiment of the present invention; FIG. FIG. 3 is a side view (partially omitted side view) showing one edge extending in the second direction of the building board shown in FIG. 1 ; FIG. 2 is a side view (partially omitted side view) showing one edge extending in the first direction of the building board shown in FIG. 1 ; It is sectional drawing of each place in a 1st joint groove. (a) represents the cross section of the first shallow region of the shallow graben, (b) represents the cross section of the second shallow region of the shallow graben, and (c) represents the third shallow region of the shallow graben. (d) represents a cross section of a deep joint ditch. It is a sectional view showing an example of the depth change of a shallow graben. It is a sectional view showing an example in case a deep joint ditch is provided with a change in depth. FIG. 2 is a partially enlarged plan view of the building board shown in FIG. 1; FIG. 2 is another partially enlarged plan view of the building board shown in FIG. 1; FIG. 2 is a cross-sectional view of a first edge and its vicinity in a state in which two building boards are joined together via their first edges; FIG. 4 is a plan view of the first edges and the vicinity thereof in a state in which two building boards are joined together via their first edges; FIG. 4 is a cross-sectional view of the second edges and the vicinity thereof in a state in which two building boards are joined together via their second edges; FIG. 4 is a plan view of the second edges and the vicinity thereof in a state in which two building boards are joined together via their second edges; 3 shows a construction structure of a wall portion using a plurality of building boards according to the present embodiment.

1 to 3 represent a building board X according to one embodiment of the invention. FIG. 1 is a plan view of a building board X. FIG. FIG. 2 is a side view (partially omitted side view) of the building board X. FIG. FIG. 3 is another side view (partially omitted side view) of the building board X. FIG.

The building board X is a building board material for forming the outer wall and the inner wall of a building, and as shown in FIG. , E2 and edges E3 and E4, which are a pair of second edges extending in a second direction D2 that intersects the first direction. The first direction D1 and the second direction D2 are orthogonal in this embodiment. When constructing a wall using building boards X, a plurality of building boards X are spliced together vertically (vertically) or horizontally (horizontally).

The dimension of the building board X in the first direction D1 is, for example, approximately 1820 to approximately 3030 mm. The dimension of the building board X in the first direction D2 is, for example, approximately 455 to approximately 910 mm. The thickness of the building board X is, for example, approximately 14 to approximately 26 mm. Also, the building board X is, for example, a cement board, a concrete board, or a wooden board.

The building board X has a plurality of joint grooves 10 (first joint grooves) and a plurality of joint grooves 20 (second joint grooves) on its design surface S, and the contour shape is defined by these joint grooves 10 and 20. It has a plurality of designed convex portions 30 . The joint grooves 10 and 20 are grooves formed on the design surface S of the building board X so as to form a pseudo joint groove.

Each joint groove 10 is a through joint extending in the first direction D1. Each joint groove 10, for example, is a state in which two building boards X are joined continuously via a second edge E3 of one building board X and a second edge E4 of the other building board X, It is arranged so as to form a part of one through joint extending over the two building boards X. The plurality of joint grooves 10 includes a plurality of shallow joint grooves 11 and a plurality of deep joint grooves 12 in this embodiment.

In this embodiment, the plurality of shallow graben 11 has a shallow region 11a (first shallow region) and a deeper shallow region 11b (second shallow region) (first type shallow grabens), and those with shallow areas 11c (third shallow areas) in addition to these (second type shallow graben). The shallow area 11c is deeper than the shallow area 11a and shallower than the shallow area 11b. In FIG. 1, the shallow area 11a is represented by solid black, and the shallow area 11b is represented by diagonal hatching.

The width w1 (shown in FIG. 4) of the groove bottom Gb of the shallow joint groove 11, that is, the length in the second direction D2 is, for example, 1.0 to 7.0 mm. The depth d1 (shown in FIG. 4(a)) of the shallow region 11a is, for example, 1.0 to 5.0 mm. The depth d2 (shown in FIG. 4(b)) of the shallow region 11b is, for example, 3.0 to 7.0 mm as long as it is greater than the depth d1. The depth d3 (shown in FIG. 4(c)) of the shallow region 11c is, for example, 2.0 to 6.0 mm as long as it is greater than the depth d1 and less than the depth d2.

In the shallow joint groove 11, the inclination angle (first inclination angle) between the side wall Gs (shown in FIG. 4) and the groove bottom Gb is 90° or less, for example, 60° in this embodiment. In the shallow graben 11, the inclination angle (second inclination angle) between the slope Gd (shown in FIG. 5) forming the boundary between the shallow areas 11a and 11b and the trench bottom Gb (second inclination angle) is 90° or less in this embodiment. , for example 60°.

The deep graben 12 is deeper than the shallow graben 11 (deeper than the shallow areas 11a, 11b, and 11c) in this embodiment. In FIG. 1, the deep joint rift 12 is represented by vertical hatching. The width w2 (shown in FIG. 4(d)) of the groove bottom Gb of the deep joint groove 12, that is, the length in the second direction D2 is, for example, 1.0 to 6.0 mm. The depth d4 (shown in FIG. 4(d)) of the deep joint groove 12 is set larger than the depths d1 to d3, and is, for example, 7.0 to 11.0 mm.
However, the deep graben 12 need not be deeper than all of the shallow areas 11a, 11b, and 11c as in this embodiment, and may be set deeper than the depth d1 of the shallowest shallow area 11a.

The plurality of deep joint rifts 12 may include deep joint rifts 12A as shown in FIG. The deep graben 12A includes a deep catch region 12a (first deep catch region) and a deeper deep catch region 12b (second deep catch region). The depth d4' of the deep joint groove 12a is, for example, 7.0 to 9.0 mm, and the depth d4'' of the deep joint groove 12b is, for example, 9.0 to 11.0 mm as long as it is greater than the depth d4'. be.

In the deep joint groove 12, the inclination angle (third inclination angle) between the sidewall Gs (shown in FIG. 4(d)) and the groove bottom Gb is 90° or less, for example, 60° in this embodiment. In the deep-seated graben 12A, the slope Gd (shown in FIG. 6) forming the boundary between the deep-seated regions 12a and 12b forms an inclination angle (fourth inclination angle) with the trench bottom Gb in this embodiment, which is 90° or less. , for example 60°.

In this embodiment, each joint groove 10 has groove bottoms Gb having the same length in the second direction D2 at one end and the other end (that is, the edge E1 and the edge E2) in the first direction D1. Specifically, the width w1 of the groove bottom Gb of each shallow joint groove 11 is the same at one end and the other end in the first direction D1 of the shallow joint groove 11, and the width w1 of the groove bottom Gb of each deep joint groove 12 The width w2 is the same at one end and the other end of the deep joint groove 12 in the first direction D1.

In such a configuration, when a plurality of building boards X having the same shape are joined together via their second edges, each joint groove 10 of one building board X and each joint of the other building board X It is suitable for joining with the graben X to form a continuous through joint, and therefore suitable for suppressing the conspicuousness of the joint.

In this embodiment, the width of the groove bottom Gb (the length in the second direction D2) at one end of the joint groove 10 in the first direction D1 is not the same among the plurality of joint grooves 10 . Instead of such a configuration, the width of the groove bottom Gb at the one end of the joint groove 10 in the first direction D1 may be the same among the plurality of joint grooves 10 . Further, in the present embodiment, the width of the groove bottom Gb (the length in the second direction D2) at the other end of the joint groove 10 in the first direction D1 is not the same among the plurality of joint grooves 10. . Instead of such a configuration, the width of the groove bottom Gb at the other end of the joint groove 10 in the first direction D1 may be the same among the plurality of joint grooves 10 .

On the design surface S, each joint groove 20 extends in the second direction D2 and is connected to at least one joint groove 10, and the plurality of joint grooves 20 are arranged so as to extend from one joint groove 10 to another joint groove 10. includes a joint groove 20 extending in the second direction D2. The plurality of joint grooves 20 includes joint grooves 20 intersecting at least one joint groove 10 between one joint groove 10 and another joint groove 10 in the present embodiment. Further, the plurality of joint grooves 20 may include joint grooves 20 that are not perpendicular to the joint groove 10 and that are inclined. For the joint groove 20 as described above, for example, like the shallow joint groove 11, the depth of the groove may be varied.

The plurality of design protrusions 30 include a plurality of design protrusions 30B having linear joints 31 . The linear joint 31 is a linear partition that creates discontinuity in the first direction D1 in the appearance of the design convex portion 30. It is a partition that creates a step in the thickness direction of the building board between (partial convex portions). The linear joint 31 extends, for example, in the second direction D2.

Two portions 30b adjacent to each other via a linear joint 31 are, for example, as shown in FIG. They may be displaced from each other in D2.

As shown in FIG. 2, the building board X has a superstructure portion 41 for joint joining at the edge E1 and the vicinity thereof, and joint joining at the edge E2 and the vicinity thereof. It has an underlying structure 42 for. A sealing portion 43 may be provided in the upper and lower structural portions 41 and 42 to fill the gaps between the members in jointing. In this embodiment, the sealing portion 43 is linearly provided on the lower structure portion 42 . The sealing portion 43 is, for example, an adhesive such as hot melt.

Two building boards X can be joined together via their first edges (edges E1, E2). Specifically, the edge E1 side of one building board X and the edge E2 side of the other building board X can be joined together by jointing as shown in FIG. In a state in which two building boards X are joined via their first edges (edges E1 and E2), as shown in FIG. , a joint groove 10M is formed as a through joint extending in the first direction D1. The above-described upper structural portion 41 and lower structural portion 42 are designed with dimensions and a shape in which such a joint groove 10M is formed.

As shown in FIG. 3, the building board X has a superstructure portion 44 for joint jointing at the edge E3 and its vicinity, and joint joints at the edge E4 and its vicinity. It has an underlying structure 45 for. A sealing portion 46 may be provided in the upper and lower structural portions 44 and 45 to fill the gaps between the members in the mating joint. In this embodiment, the sealing portion 46 is linearly provided on the lower structure portion 45 . The sealing portion 46 is, for example, an adhesive such as hot melt.

Two building boards X can be joined together via their second edges (edges E3, E4). Specifically, the edge E3 side of one building board X and the edge E4 side of the other building board X can be joined together by jointing as shown in FIG. In the state where the two building boards X are joined via their second edges (edges E3 and E4), as shown in FIG. , there is a portion where the joint groove 20M extending in the second direction D2 is formed. The above-described upper structural portion 44 and lower structural portion 46 are designed with dimensions and a shape in which such a joint groove 20M is formed.

When constructing a wall using the building board X having the above structure, a plurality of building boards X are joined together in the vertical direction (longitudinal direction) and the horizontal direction (horizontal direction). Specifically, the first edges (edges E1 and E2) of the plurality of building boards X are spliced together in the vertical direction, for example, and the plurality of building boards X are joined together at the second edges (edges E1 and E2). Edges E3 and E4) are spliced together in the horizontal direction, for example.
When a plurality of building boards X are spliced together in the vertical direction or the horizontal direction, if there are gaps between the building boards X due to unevenness or the like, the gaps may be filled with sealing, for example.

FIG. 13 shows an example of a wall construction structure using a plurality of building boards X. As shown in FIG. In the example of the wall portion construction structure shown in FIG. 13, two building boards X in each row are spliced and connected in the vertical direction (second direction D2) via their first edges (edges E1 and E2). Also, two building boards X in each row are spliced in the left-right direction (first direction D1) via their second edges (edges E3 and E4).

The building board X having the above-described configuration can be used to suppress conspicuousness of the seamed portions and their deviations in such a construction state in which a plurality of building boards X are joined together (that is, in a wall construction structure using the building board X). Suitable. Specifically, it is as follows.

As described above, on the design surface S of the building board X, a plurality of joint grooves 10 are formed as through joints. 12 (the multiple joint grooves 10 do not all have a common groove depth). As described above with reference to FIG. 10, the joint groove 10M is formed as a through joint extending in the first direction D1 at the joint location C1 between the building boards X adjacent in the vertical direction. The joint groove 10M resembles each joint groove 10 (shallow joint groove 11, deep joint groove 12) which is a through joint on the design surface S.

The joint groove 10M as a through joint at the joint location C1 and the plurality of joint grooves 10 as through joints on the design surface S are spaced apart from each other in the second direction D2 and arranged in parallel, and have a common groove depth. not. Therefore, the joint groove 10M, which is a through joint at the joint location C1, is suppressed from being conspicuous. That is, the plurality of joint grooves 10 (shallow joint grooves 11 and deep joint grooves 12) on the design surface S of the building board X suppress the conspicuousness of the joint grooves 10M, and consequently the joint location C1 itself is suppressed from being conspicuous. do.

Further, the above-described joint groove 20M extending in the second direction D2 formed at the joint C2 (shown in FIG. 12) between the building boards X adjacent in the left-right direction is also formed on the design surface S in the second direction D2. , each joint groove 20 extending into the . Therefore, the plurality of joint grooves 20 on the design surface S of the building board X suppress conspicuousness of the joint grooves 20M formed at the joint portion C2, and consequently, conspicuousness of the joint portion C2 itself.

In addition, the joint grooves 10 of the building board X include shallow joint grooves 11 with varying depths, as described above. The depth change or step in the shallow joint groove 11 resembles the step formed when there is a deviation in the thickness direction between the adjacent building boards X at the joint portion C2 described above. Moreover, in the plurality of joint grooves 10, the depth change or step in the shallow joint groove 11 shallower than the deep joint groove 12 is conspicuous. Such a change in the depth of the shallow joint 11 suppresses conspicuousness of a step formed when there is a deviation in the thickness direction between adjacent building boards X at the seam C2.

Furthermore, as a result of the deviation in the second direction D2 occurring between the adjacent building boards X at the seam C2 described above, a step or positional deviation in the second direction D2 occurred between the design surfaces S of the adjacent building boards X. In this case, the depth change or level difference in the shallow joint ditch 11 suppresses the level difference or positional deviation from being conspicuous. Further, even when there is no deviation in the second direction D2 between the adjacent building boards X, the depth change or level difference in the shallow joint 11 disperses the attention to be focused on the seam C2, making the seam C2 conspicuous. suppress

As described above with reference to FIG. 7, the plurality of design convex portions 30 on the building board X have at least one of the joint grooves 10 that are adjacent to each other via one joint groove 20 and face in common. A pair of design protrusions 30A are included in which boundary lines L1, L1 formed with the groove bottom Gb are displaced from each other in the second direction D2. Such a misaligned shape between the design convex portions 30A adjacent to each other through the joint groove 20 may be caused when the adjacent building boards X are misaligned in the second direction D2 at the seam portion C2. , similar to the positional deviation shape between the design convex portions 30 adjacent to each other through the joint groove 20M extending in the second direction D2, and conspicuousness thereof is suppressed.

In addition, as described above, the plurality of design protrusions 30 of the building board X have linear joints 31 (linear partitions that create discontinuity in the first direction D1 in the appearance of the design protrusions 30). A plurality of design convex portions 30B are included. The linear joint 30 as a partition resembles a discontinuous shape in the first direction D1, such as a step formed when the adjacent building boards X are displaced in the thickness direction at the above-mentioned joint C2. , thus suppressing its prominence.

As described above with reference to FIG. 8, the two portions 30b adjacent to each other via the linear joint 31 have boundary lines L2, L2 formed with the groove bottom Gb of at least one of the joint grooves 10 facing in common. They may be displaced from each other in the second direction D2. Such a misaligned shape between the portions 30b (partial convex portions) adjacent to each other via the linear joint 30 is a joint ( (extending in the second direction D2).

As described above, when a plurality of building boards X are joined together (that is, in a construction of a wall using building boards X), conspicuousness of jointed parts and their deviations can be suppressed.

X Building boards E1 to E4 Edge S Design surface D1 First direction D2 Second direction 10 Joint groove (first joint groove)
11 Shallow graben 11a Shallow area (first shallow area)
11b Asame Area (Second Asame Area)
11c Asame Area (3rd Asame Area)
12 Fukame graben 12a Fukame area (first Fukame area)
12b Fukame area (Second Fukame area)
Gb groove bottom 20 joint groove (second joint groove)
30, 30A, 30B design convex portion 30b portion (partial convex portion)
31 Linear joints 41, 44 Upper concrete structure parts 42, 45 Lower concrete structure parts 43, 46 Sealing part

Claims (7)

A building board having an outline shape defined by a pair of first edges extending in a first direction and a pair of second edges extending in a second direction intersecting the first direction and having a design surface,
In the design surface, a plurality of first joint grooves that are through joints extending in the first direction, a plurality of second joint grooves extending in the second direction and connected to at least one first joint groove, and the first and a plurality of design convex portions whose outer shape is defined by the second joint groove,
The plurality of first rifts include at least one shoal rift including a first shoal region and a second shoal region deeper than this, and at least one deep rift deeper than the shallow rift. Including, building board. A pair of designs in which boundary lines formed by groove bottoms of at least one of the first joint grooves that are adjacent to each other through one second joint groove and that face in common are displaced from each other in the second direction 2. The building board according to claim 1, which has projections. The building board according to claim 1 or 2, wherein the plurality of design projections include design projections having linear joints extending in the second direction. The design convex portion having the linear joint has two partial convex portions adjacent to each other through the linear joint, and the two partial convex portions are at least one of the first joint grooves facing in common. 4. The building board according to claim 3, wherein the boundary lines formed with the groove bottoms are displaced from each other in the second direction. The building board according to any one of claims 1 to 4, wherein each first joint groove has groove bottoms having the same length in the second direction at one end and the other end in the first direction. The plurality of first rift trenches comprise a first shallow region, a second shallow region deeper than this, a third shallow region deeper than the first shallow region and shallower than the second shallow region, 6. The building board according to any one of claims 1 to 5, comprising at least one shallow ditch containing The construction according to any one of claims 1 to 6, wherein said plurality of first rift rifts comprise at least one deep rift including a first deep rift region and a second deeper rift region. board.

Images