JP6990105B2 - Flat roof tile - Google Patents

Description

The present invention relates to a flat roof tile that is resistant to water leakage even under strong wind and rain and can cope with a gentle slope. In the present specification, the upstream side in the flow direction of the roof tile may be referred to as the tail side, and the downstream side may be referred to as the head side.

As a recent market condition for roofs, the number of gently sloping mono-pitched roofs is increasing. This is related to the installation of solar panels. When installing solar panels, flat roofs that can be installed at any angle were initially sold rather than gable roofs and hipped roofs, but there are concerns that flat roofs are prone to leaks and snow. be. Therefore, in recent years, these concerns have been lessened, and there has been a shift to mono-pitched roofs that can be equipped with many solar panels if one is facing south. The preference of younger generations for mono-pitched roof designs has also contributed to the increase.

However, for mono-pitched roofs, the length of the roof flow increases and the amount of rain received increases, the roof becomes taller and more susceptible to strong winds, the roof becomes taller and more susceptible to restrictions on the north diagonal line, and the roof area and wall area There are problems such as the back of the hut becoming large and the construction cost increasing.

Therefore, recently, the slope of mono-pitched roofs is increasing. The roof slope is expressed by the height per 10 inches of horizontal distance, and the slope is gentle when the slope is 3.5 inches (19.3 degrees) or less, and steep when the slope is 5.5 inches (28.8 degrees) or more. It is usually called a gradient. On gentle slopes, the length of the roof flow is small and the amount of rain is reduced, the roof is low and less susceptible to strong winds, the roof is low and less susceptible to the restrictions of the north diagonal line, and the roof area / wall area and the back of the hut become smaller. There are advantages such as reduction of construction cost and no need for roof scaffolding.

However, in the case of a roof made of roof tiles, the gentler the slope, the more the wind that blows up will push up the rainwater on the roof tiles that have slowed down due to the gentle slope, and the lower roof tiles and the upper roof tiles. There is a risk that it will infiltrate between the roof tiles and leak beyond the water return at the bottom of the lower roof tile, accelerating the corrosion of roof bases such as field boards and other building materials, and shortening the life of the building. Therefore, as a gentle gradient, a 3 inch gradient (16.7 degrees) was the de facto lower limit.

However, recently, there are cases where a tiled roof is also required to have a slope of 2.5 inches (14.0 degrees) or a gentler slope. In order to cope with such a gentle gradient, it is difficult to use conventional roof tiles, and new roof tiles are required that are designed so that the wind and rain that blows up are difficult to infiltrate and water leaks even if the wind and rain infiltrate.

Flat roof tiles, which are the mainstream of current residential tiles, have a square plate-shaped roof tile with a substantially flat surface, an overlap on one side of the roof tile body, and an underlap on the other side of the roof tile body. It has a raised part on the buttock side of the roof tile body and a head finding at the head end of the roof tile body. There are various types of this flat roof tile.

Regarding the so-called full-flat type flat roof tile in which the surface of the tile body and the overlap surface are flush with each other, the applicant has previously proposed Patent Document 1 and the like as a countermeasure against a gentle gradient.

As shown in FIG. 13, a terrace-shaped overlap 83 higher than the roof tile body 82, a jetty 85 near the underlap, and a tail raising portion 86 are provided, and a straddle portion 89 is recessed in a mountain shape in the central portion in the width direction of the head finding 87. The present applicant has proposed Patent Documents 2 and 3 and the like for the so-called U-type flat roof tile 81, but as will be described later, measures for dealing with gentle slopes are still insufficient.

Patent Document 4 shows a ridge near the bottom of the surface of the terraced overlap, but there is no explanation for it.
Patent Document 5 describes a tile having a first ridge formed at a position where the lower end of the head hanging is in contact with the roof tile when the roof tile is laid.

Japanese Unexamined Patent Publication No. 2017-8557 Japanese Unexamined Patent Publication No. 9-170296 Japanese Unexamined Patent Publication No. 2001-40821 Japanese Unexamined Patent Publication No. 2017-128937 Japanese Unexamined Patent Publication No. 4-309646

As in Patent Documents 2 to 5, U-type flat roof tiles are staggered, terrace-shaped overlaps overlap above the underlaps of adjacent roof tiles in the same stage, and the lower end of the head finding abuts on the reference plane of the lower roof tile. , The straddle part straddles the adjacent terraced overlap and the jetty near the underlap (hereinafter collectively referred to as "pier"). The straddle portion needs to be designed to be large so that a gap of, for example, about 3 mm is formed between the upper part and both sides of the pier for the following three reasons. The first is to allow a margin at the time of manufacturing. Secondly, it is used for fine adjustment of the left and right positions during construction. Thirdly, when installing the retrofitted snow stopper after thatching, it is easy to insert a part of the bracket. Therefore, the wind and rain that blows up on the roof tiles infiltrate the tail side through the gap between the straddle and the pier.

(A) In the case of a normal slope, the wind and rain that infiltrated through the gap between the central upper side of the straddle and the upper surface of the pier is the tail end water return provided at the tail end of the stepped overlap (there is only one). It is dammed by (low), but in the case of a gentle slope, it is easy for water to leak from the buttock over the buttock end water return while pushing up the rainwater on the tile whose flow has slowed down due to the gentle slope.

(B) Wind and rain that infiltrate through the gap between both sides of the straddle and both sides of the pier is dammed by the water return surface of the raised buttock in the case of a normal slope, but is gentle in the case of a gentle slope. While pushing up the rainwater on the tile whose flow has slowed down due to the slope, it climbs up the water return surface of the buttock raising part, and further, it easily leaks from the buttock beyond the upper surface of the buttock raising part.
If the depth of the upper surface of the buttock raising portion is as large as 30 mm or more, it is difficult for rainwater to pass over the upper surface. When stacking and storing the roof tiles, there is a recess for engaging the sword of the upper tile) and the depth is often 20 mm or less, so rainwater can easily pass over the upper surface.

Next, a gap is created between the roof tile body after roofing and the head end of the underlap of the upper roof tile due to the limit of accuracy of the clay tile and the unavoidable deformation during firing. Further, as shown in FIG. 13 (Patent Document 2), a notch 90 is formed at the lower part of the head finding 87 on the overlap 83 side, and a tongue-shaped portion is fitted into the notch 90 of the adjacent roof tile at the head end portion of the underlap 84. Even if the projecting piece 91 is provided, a gap is generated between the roof tile main body 52 after the roofing and the projecting piece 91 of the upper roof tile. Therefore, the wind and rain that blows up on the roof tiles infiltrate the buttock side through these gaps under the head end of the underlap.

(C) Underlap The wind and rain that has entered through the gap below the head end flows straight to the buttock side, and also deviates diagonally outward and flows to the buttock side. In the case of a normal slope, the wind and rain flowing straight to the buttock side is dammed up on the way up the water return surface of the buttock raising part, but in the case of a gentle slope, the buttock while pushing up the rainwater on the tile whose flow has slowed down due to the gentle slope. It is easy for water to leak from the buttock by climbing up the water return surface of the raised part and further exceeding the upper surface of the buttock raised part. In addition, the wind and rain that deviates diagonally outward and flows to the buttock side is dammed while climbing the water return surface of the buttock raising part diagonally in the case of a normal gradient, but in the case of a gentle slope, the water return surface of the buttock raising part is stopped. It climbs up diagonally, and it is easy for water to leak from the buttocks beyond the upper surface of the raised part of the buttocks.

Due to the above problems (a) to (c), the waterproof performance of the current U-type flat roof tiles has only passed the waterproof test with a 3.5 inch gradient (rainfall 4 L / m ² min). It was easy for water to leak when the roof was laid on a gentler slope.

Therefore, an object of the present invention is to deal with the above problem (c) in particular, and to provide a flat roof tile that is less likely to leak water even if the wind and rain that blows up enters through the gap under the head end of the underlap, and thus can cope with a gentle gradient. To do.

The present invention has a square plate-shaped roof tile with a substantially flat surface, a hill-shaped overlap that is higher than the tile body on one side of the tile body, and an under that is lower than the tile body on the other side of the tile body. The wrap, the jetty near the underlap between the tile body and the underlap, which is higher than the tile body, the tail raised part higher than the tile body on the tail side of the tile body, and the head protruding below the head end of the tile body. In the center of the width direction of the head finding, there is a straddle that straddles the hill-shaped overlap and the jetty near the underlap (hereinafter collectively referred to as "pier") adjacent to the lower tiles at the time of roofing. It is characterized in that the following means [3] are adopted in the recessed flat roof tile.
Further, in addition to the means [3], any one or a plurality of the following means [1], [2], [4] to [7] can be adopted.

[1] The first water return extending in the left-right direction in order from the head side to the tail side at least on the upper surface of the stepped hill-shaped overlap of the pier, which is on the tail side of the straddle of the upper tile at the time of roofing. And a third water return extending in the left-right direction are provided at a distance, and the left-right direction is located on the back surface of the roof tile between the first water return and the third water return of the lower roof tile at the standard working length. A second water return extending to the roof tile was provided.
As shown in FIG. 6, the standard working length time means that the working length is set to the design standard value and thatched. When the working length of the roof tile is adjusted to increase or decrease from the standard working length (hereinafter sometimes referred to simply as "working length adjustment"), the second water return is better than the first water return of the lower roof tile. It may be on the head side, or it may be on the tail side of the third water return of the lower roof tile.

Without this configuration, as described in problem (a) above, in the case of a gentle slope, wind and rain infiltrated from the gap between the upper center of the straddle and the upper surface of the pier (hereinafter sometimes referred to as the "central gap of straddle"). Is easy to leak from the buttocks.

With this configuration, even in the case of a gentle slope, the wind and rain that infiltrated from the central gap across the straddle is first dammed by the first water return and the flow is turned diagonally upward, and then the flow is stopped by the second water return. It is turned diagonally downward and then dammed by a third water return. In this way, the first to third water returns are controlled so that the wind and rain meander up and down and are dammed up, so that water leakage from the hips can be prevented.

Further, a fourth water return extending in the left-right direction may be provided at a distance from the third water return on the upper surface of at least the terraced overlap of the pier. Even if there is rainwater that gets over the third water return, it will be dammed up by the fourth water return.

The left-right length of the first to fourth water returns (total length when provided on both the upper surface of the terraced overlap and the upper surface of the jetty near the underlap) is not particularly limited, but is the center upper side of the straddle. 50% or more of the left-right width is preferable, and 60% or more is more preferable. In particular, the left-right width of the first to second water returns is preferably 80% or more, more preferably 90% or more, of the left-right length of the central upper side of the straddle portion.

The width of the hem of the first to fourth water returns is not particularly limited, but is preferably 4 to 10 mm, more preferably 6 to 10 mm. If it is less than 4 mm, it is easy for rainwater to get over, and if it exceeds 10 mm, it is difficult for rainwater to get over.

It is preferable that the first water return and the third water return of the terrace-shaped overlap are connected by a connecting ridge on the side edge of the terrace-shaped overlap.

It is preferable that the drainage ditch between the third and fourth water returns of the terraced overlap slopes downward toward the side edge of the terraced overlap and is open to the outside at the side edge.

The height of the first to third water returns is not particularly limited, but as shown in FIG. 6D, the height of the space between the upper surface of the pier and the back surface of the tile body of the upper tile (hereinafter referred to as "terrace"). (Sometimes referred to as "upper space height") is M, the height of the first water return (from the upper surface of the terrace) is m1, and the height of the second water return (projection dimension from the back surface of the tile body) is m2. As for m1 + m2, 60 to 100% of M is preferable, and 70 to 95% is more preferable. If this ratio is less than 60%, the control of the wind and rain flow will be weakened. If this ratio exceeds 100%, the working length adjustment is restricted where the first water return and the second water return interfere with each other.

Also, let the height of the third water return (from the top of the pier) be m3.
-M1 ≦ m3 is preferable, and m1 <m3 is more preferable. This is to firmly dam the wind and rain whose flow is controlled by the first water return and the second water return by the third water return.
In this case, m2 ≦ m1 ≦ m3 is preferable, and m2 <m1 <m3 is more preferable. This is because the first water return is responsible for both damming and controlling the flow, the second water return is mainly responsible for controlling the flow of wind and rain, and the third water return is mainly responsible for damming the wind and rain.
However, m1 <m2 <m3 may be satisfied.
-M1 is preferably 40 to 80% of M, m2 is preferably 15 to 60% of M, and m3 is preferably 60 to 100% of M.
-M1 is more preferably 50 to 80% of M, m2 is more preferably 15 to 40% of M, and m3 is more preferably 80 to 95% of M.

The height of the fourth water return (from the upper surface of the pier) is not particularly limited, but the height of the fourth water return is m4, and m4 is preferably 40 to 100% of M, more preferably 60 to 95%. ..

As shown in FIG. 6 (e), the distance from the back surface K of the head finding to the head side hem F of the first water return is not particularly limited, but is preferably 3 to 20 mm, preferably 5 to 15 mm at the time of standard thatching. More preferred. If it is less than 3 mm, the adjustment range for increasing the working length becomes small. If it exceeds 20 mm, the effect of the first water return to dam the wind and rain becomes small.

The distance from the tail side hem I of the first water return to the head side hem J of the third water return is not particularly limited, but is preferably 10 to 35 mm, more preferably 15 to 30 mm. Whether it is less than 10 mm or more than 35 mm, the control of meandering in the wind and rain is weakened.

At the time of standard thatching, the head side hem D and the buttock side hem E of the second water return are
-It is preferable that the range L1 is from the head side hem F of the first water return to the head side hem J of the third water return.
It is more preferable that the range L2 is from the midpoint G between the head side hem F and the buttock side hem I of the first water return to the head side hem J of the third water return.
-It is more preferable that the range L3 is from the 2/3 point H near the buttock side hem of the head side hem F and the buttock side hem I of the first water return to the head side hem J of the third water return.
Whether D and E are on the buttock side or the head side of the range L1, the control of the wind and rain flow is weakened.

-It is preferable to provide a horizontal water return extending in the vertical direction from the surface of the tile body and continuous with the first water return on each side surface of the pier. This is because it is possible to dam the wind and rain that infiltrate through the straddling lateral gap.
The lateral water return preferably extends laterally from the lower end of each lateral surface of the pier to the surface of the tile body 10 to 50 mm (more preferably 20 to 40 mm, most preferably 25 to 35 mm) laterally. If the lateral extension of the lateral water return is small, the effect of damming the wind and rain that infiltrates through the straddling lateral gap becomes small. Even if the lateral extension of the horizontal water return is too large, the effect of damming the wind and rain that infiltrates through the straddling lateral gap will reach a plateau, and if the snow stopper is attached to the roof tile in advance, it will easily interfere with the bracket. ..

Regarding the mode of the horizontal water return, the explanation in the following [2] is referred to.

[2] On each side surface of the pier, a horizontal water return extending in the vertical direction was provided at a position on the tail side of the straddling portion of the upper roof tile at the time of roofing.

Without this configuration, as described in problem (b) above, in the case of a gentle slope, the gap between both side surfaces of the straddle portion and both side surfaces of the pier (hereinafter sometimes referred to as "straddling lateral gap"). The wind and rain that infiltrated from the bottom easily leaks from the buttocks.

With this configuration, even in the case of a gentle slope, the wind and rain that infiltrated from the straddling lateral gap is dammed by the horizontal water return, and even if it gets over a part, it is dammed by the water return surface of the raised part of the buttocks, so water leakage from the buttocks. Can be prevented.

The horizontal water return preferably extends from the surface of the tile body to at least the upper end of each side surface of the pier.
Further, it is preferable that the lateral water return extends laterally from the lower end of each lateral surface of the pier to the surface of the roof tile body separated from the lower end by 10 to 50 mm (more preferably 20 to 40 mm, most preferably 25 to 35 mm) laterally. .. If the lateral extension of the lateral water return is small, the effect of damming the wind and rain that infiltrates through the straddling lateral gap becomes small. Even if the lateral extension of the horizontal water return is too large, the effect of damming the wind and rain that infiltrates through the straddling lateral gap will reach a plateau, and if the snow stopper is attached to the roof tile in advance, it will easily interfere with the bracket. ..

The front view shape of the lateral water return extending in the lateral direction is not particularly limited, and is a trapezoid as shown in FIGS. 5, 7 and the like, and an arc as shown in FIGS. 8 (a) to 8 (d). Examples thereof include a shape, a rectangle, a triangle, and a trapezoid having an uneven upper edge.
However, the front view shape of the horizontal water return is such that the height of the lateral end extending in the lateral direction is lower than the height of the base end in contact with each lateral surface of the pier (trapezoid, triangle, arc shape, etc.). , It is preferable because it is not easily damaged.
It is preferable in terms of design that the front view shape of the lateral water return on the terrace-shaped overlap side and the front view shape of the horizontal water return on the jetty side near the underlap are substantially symmetrical with respect to the pier.

Further, as shown in FIG. 8 (e), the lateral end portion or the entire lateral water return may be inclined toward the head side.
Further, as shown in FIG. 8 (f), a glaze dispersion groove 39 extending in the left-right direction straddling the lateral end portion of the lateral water return on the surface of the tile body immediately adjacent to the head side of the lateral end portion of the horizontal water return. May be provided.
In the glaze dispersion groove 39, in the glaze process (pour the glaze on the roof tile surface) at the time of manufacturing the roof tile, the glaze applied to the buttock side (or the buttock side of the diagonal water return) of the horizontal water return is used for the horizontal water return. When the water flows toward the head side more concentrated than the lateral end (or the cut between the lateral end and the lateral end of the diagonal water return), the flow is dispersed to the left and right to prevent color unevenness. .. Further, the glaze dispersion groove 39 substantially increases the effective height of the horizontal water return, and further enhances the waterproof performance of the horizontal water return.
The length of the glaze dispersion groove 39 is not particularly limited, but is preferably 15 to 60 mm, more preferably 20 to 50 mm. If it is less than 10 mm, the above effect is weakened. Even if it exceeds 60 mm, the above effect does not change. The depth of the glaze dispersion groove 39 is not particularly limited, but is preferably 1 to 3 mm, more preferably 2 to 3 mm. If it is less than 1 mm, the above effect is weakened. If it exceeds 3 mm, the wall thickness under the groove becomes thin, and it becomes easy to be distorted in the self-standing firing process.

As shown in FIG. 5B, where N is the height of the space between the front surface of the roof tile body and the back surface of the roof tile body of the upper roof tile, the highest point of the horizontal water return height n is 80 to 80 of N. 100% is preferable, and 92 to 98% is more preferable. If this ratio is less than 80%, the effect of damming the wind and rain that infiltrates through the straddling lateral gap becomes small. If this ratio exceeds 100%, the horizontal water return and the back surface of the upper roof tile will interfere with each other, and the upper roof tile will be lifted (then, a gap will be created in the head finding and rainwater will easily infiltrate, and after construction, it will be easier to infiltrate. The aesthetics are spoiled.)

The width from the head side hem to the buttock side hem of the lateral water return is not particularly limited, but is preferably 4 to 10 mm, more preferably 6 to 10 mm. If it is less than 4 mm, it is easy for rainwater to get over, and if it exceeds 10 mm, it is difficult for rainwater to get over.

It is preferable to provide a (first) water return that continuously extends in the left-right direction from the upper end of the horizontal water return on the upper surface of the pier. This is because it is possible to dam the wind and rain that infiltrate through the central gap between the straddles. In addition, by providing this (first) water return, the horizontal water return on the terrace-shaped overlap side, the (first) water return, and the horizontal water return on the jetty side near the underlap can be laterally laid. They form an integrated waterproof wall side by side. Then, even if the (first) wind and rain dammed by the water return detours sideways and tries to wrap around to the buttock side, it can be dammed by the side water return.

At the time of standard thatching, the distance from the back surface of the head finding to the head side hem of the horizontal water return is preferably 3 to 20 mm, more preferably 5 to 10 mm. If this distance is as small as possible, it is effective in preventing the intrusion of wind and rain, but if it is less than 3 mm, the adjustment range when increasing the working length becomes small. If it exceeds 20 mm, the lateral water return will be too close to the water return surface of the raised tail portion, and sufficient drainage space between them cannot be secured.

[3] The rising angle (angle α in FIG. 9C) of the water-returning surface of the raised tail portion with respect to the surface of the roof tile is set to 50 to 87 degrees, and it is located on the outer side of the underlap of the upper roof tile after roofing. An oblique water return was provided from the water return surface of the raised part to the surface of the tile body.

Without this configuration, as described in problem (c) above, in the case of a gentle slope, the gap between the roof tile body after thatching and the head end of the underlap of the upper roof tile (or the protrusion described later) (hereinafter referred to as "" It is sometimes called the "underlap under the head gap".) It is easy for wind and rain to leak from the bottom.

With this configuration, even in the case of a gentle slope, the wind and rain that infiltrates through the gap under the underlap head and flows straight to the buttock side is dammed up on the way up the water return surface of the buttock raising part, and the underlap head end. The wind and rain that infiltrates through the lower gap and flows diagonally outward and flows to the buttock side can be dammed by the diagonal water return while climbing the water return surface of the buttock raising portion diagonally, so that water leakage from the buttock can be prevented. In addition, since the wind and rain dammed by the diagonal water return is returned to the head side by the diagonal water return, it can be drained smoothly without gathering at the corners between the raised tail and the jetty near the underlap.

If the rising angle of the water-returning surface of the tail raising portion with respect to the surface of the roof tile body is less than 50 degrees, the effect of damming wind and rain becomes small, and if it exceeds 87 degrees, the clay molded product becomes difficult to come off from the mold during roof tile manufacturing. The rising angle is preferably 60 to 85 degrees.

The distance from the side edge of the head side hem of the diagonal water return, which is the closest to the side edge of the underlap of the upper roof tile, is not particularly limited, but is preferably 20 to 40 mm, more preferably 25 to 30 mm. Even if it is less than 20 mm or more than 40 mm, the effect of the diagonal water return to stop the wind and rain becomes small.

The angle (angle β in FIGS. 3 (b) and 9 (b)) of the head side hem of the oblique water return with respect to the left-right direction is not particularly limited, but 90 to 160 degrees is preferable in a plan view, and 120 to 150 degrees is preferable. More preferred. If it is less than 90 degrees, the effect of diagonal water return to stop the wind and rain becomes small. If it exceeds 160 degrees, the effect of the diagonal water return to return the wind and rain to the head side becomes small.

The width of the upper surface of the oblique water return is preferably 4 to 10 mm, more preferably 6 to 10 mm. If it is less than 4 mm, it is easy for rainwater to get over, and if it exceeds 10 mm, the effect that rainwater does not get over remains the same.

It is preferable to form a notch at the lower part of the head finding on the overlap side, provide a protrusion to be fitted into the notch at the head end of the underlap, and make the lower surface of the protrusion into an oblique shape that rises toward the side end. With the protrusions, as in Patent Documents 2 and 3, rainwater flowing through the underlap can be drained to the outside of the tile more smoothly. However, since the projecting piece is thinner than the other parts, it is easily broken. Therefore, when the worker walks on the roof tile, the lower surface of the roof tile is raised toward the side end so that the projectile does not crack due to strong pressure on the lower roof tile and it is easy to find even if it cracks. It is preferable to make it into a shape and let it escape from the lower roof tile. Then, a gap (one aspect of the gap under the underlap head end) that becomes larger toward the side end side is generated between the tile body after the roofing and the projecting piece of the upper tile, and the tile is deflected diagonally outward. The wind and rain that flows to the buttock side increases.

[4] An outer water return is provided on the side edge of the upper surface of the underlap, and the upstream side diagonal part extending diagonally toward the roof tile body side by bending the head side portion of the outer water return and the insertion lateral part extending in the flow direction. It is configured to include a downstream diagonal portion that extends diagonally to the side edge side, and an engaging insertion portion for engaging the engaging convex portion of the lower roof tile is formed on the underlap side edge portion next to the insertion horizontal portion. The height of the insertion side is 6 to 8 mm, the head end of the underlap is an inclined portion that inclines diagonally downward, and the outer water return extension that continues from the downstream oblique portion and extends in the flow direction is the inclined portion. On the back side of the tile body of the adjacent roof tile, a return ridge was provided to return the wind and rain over the outer water return extension to the head side.

Without this configuration, the drainage from the buttock side of the underlap is obstructed by the wind and rain blowing from the head side, and collides with each other around the side of the outside water return. Therefore, the colliding rainwater overflows over the side of the insertion (conventional height is about 5 mm).
In addition, if the head end of the underlap is an inclined portion that inclines diagonally downward, the flow is steep in the inclined portion, and since the inclined portion has not been provided with a water return in the past, wind and rain from the head side can occur. The blow overflows from the top of the inclined part to the diagonally outward buttock side. The overflowing blow leaks to the base along the back surface of the tile body of the adjacent tile on the same stage.

With this configuration, even if the drainage from the bottom side of the underlap and the wind and rain blown from the head side collide with each other around the side of the outside water return, this colliding rainwater will be inserted sideways. Do not get over the part (height 6-8 mm).
In addition, if the head end of the underlap is an inclined portion that inclines diagonally downward, the flow becomes steeper in the inclined portion, but the wind and rain blown from the head side is dammed by the outer water return extension provided in the inclined portion. Even if it gets over the outer water return extension and overflows diagonally to the outer buttock side, the overflowed blow will be returned to the head side by the return ridge provided on the back surface of the tile body of the adjacent tile on the same stage. No water leaks to the base.

If the height of the insertion side of the outer water return is less than 6 mm, the drainage in the underlap and the blown water will collide and easily overflow, and if it exceeds 8 mm, it will interfere with the back surface of the upper roof tile and the upper roof tile will be lifted ( There will be a gap in the head of the upper roof tile, which will infiltrate rainwater and spoil the aesthetic appearance after construction.) The height of the insertion side portion is more preferably 7 to 8 mm.

The tip of the outer water return extension portion is preferably 0 to 15 mm from the head end of the underlap including the inclined portion, and more preferably 0 to 10 mm from the head side. If it protrudes from the head edge of the underlap, it is easily chipped, and if it exceeds 15 mm, the effect of damming the wind and rain blows becomes small.

The height of the barb (protruding dimension from the back surface of the roof tile body) is preferably 1 to 4 mm, more preferably 1 to 2 mm. If it is less than 1 mm, the effect of returning the wind and rain will be small, and if it exceeds 4 mm, it will easily interfere with the lower roof tile.

The length of the return ridge is preferably 100 to 180 mm, more preferably 120 to 160 mm. If it is less than 100 mm, the effect of returning the blow of wind and rain becomes small, and if it exceeds 180 mm, it tends to interfere with the underlap of the adjacent roof tile and the engaging convex portion of the lower roof tile.

[5] An outer water return is provided on the side edge of the upper surface of the underlap, an inner water return is provided on the inner part, a notch is made in the middle of the inner water return, and the head side portion of the outer water return is bent. The configuration includes an upstream diagonal portion that extends diagonally toward the roof tile body, an insertion horizontal portion that extends in the flow direction, and a downstream diagonal portion that extends diagonally toward the side edge side. An engaging insertion portion for engaging the engaging convex portion of the lower roof tile is formed, and the oblique angle (angle γ in FIG. 3B) with respect to the underlap side edge of the tail side hem of the upstream diagonal portion is 15. It was set to ~ 40 degrees.

Without this configuration, drainage from the buttock side of the underlap has a high risk of overflow if it crosses the inside water return without a notch in the middle to the outside. In addition, the risk of the overflow is high due to the conventional steep angle of inclination of the upstream diagonal portion.

With this configuration, the drainage from the tail side of the underlap tends to return inward from the notch of the inner water return even if it crosses the inner water return to the outside, so the risk of overflow is low. In addition, the gentle angle of inclination on the upstream side makes drainage smooth and the adjustment range of the working length can be expanded. The inclination angle is more preferably 25 to 35 degrees.

[6] A turbulent flow generation groove extending in the left-right direction is provided on the lower surface of the straddle portion.

Without this configuration, wind and rain can easily enter the gap between the straddle and the pier.

With this configuration, when wind and rain pass through the gap between the straddle and the pier, the turbulent flow generation groove on the lower surface of the straddle causes turbulence in the wind and rain, so the momentum of intrusion of wind and rain is increased. It can be suppressed.

The turbulence generation groove may be provided only on the central upper side of the straddle portion, may be provided only on both horizontal pieces, or may be provided on both the central upper side and both horizontal pieces. Further, it may be provided not only on the straddle portion but also on the lower surface of the head finding.

The depth of the turbulent flow generation groove is preferably 0.5 to 3 mm, more preferably 1.5 to 3 mm. If it is less than 0.5 mm, the generation of the turbulent flow due to the groove becomes weak, and if it exceeds 3 mm, molding becomes difficult (clay tends to stick to the mold during molding).

The width of the turbulent flow generation groove is preferably 1 to 4 mm, more preferably 3 to 4 mm. If it is less than 1 mm, the generation of turbulence becomes weak, and if it exceeds 4 mm, the strength of the straddle portion decreases.

Examples of the cross-sectional shape of the turbulent flow generation groove include a U-shape, a V-shape, a semicircle, and a semi-ellipse.

[7] An engaging insertion portion for engaging the engaging convex portion of the lower roof tile is formed on the side edge portion of the underlap, a downward curved concave surface is provided on the engaging convex portion, and the engaging insertion portion is provided. An engaging ridge facing the curved concave surface from below was provided.

Without this configuration, there is a concern that the tip of the downward curved concave surface of the engaging convex portion will hit the flat upper surface of the engaging insertion portion in a line, and the engaging convex portion will be damaged by the momentum. Further, when the roof tile is lifted diagonally, there is a concern that the engagement convex portion and the engagement insertion portion may be disengaged.

With this configuration, the intermediate portion (not the tip) of the downward curved concave surface of the engaging convex portion hits the engaging convex strip of the engaging insertion portion in a line or surface contact, so that the engaging convex portion is damaged. It's hard to do. Further, even when the roof tile is lifted diagonally, the engagement between the engaging protrusion and the engaging ridge is difficult to be disengaged.

The width of the engaging ridges is preferably 2 to 4 mm, more preferably 3 to 4 mm. If it is less than 2 mm, it is difficult to mold, and if it exceeds 4 mm, it is difficult for the engaging convex portion to engage with the curved ridge when the tile is laterally displaced.

The height of the engaging ridges is preferably 0.3 to 1.5 mm, more preferably 0.5 to 1.2 mm. If it is less than 0.3 mm, it is difficult to eliminate the contact with the tip of the engaging convex portion, and if it exceeds 1.5 mm, it is difficult to mold.

Examples of the cross-sectional shape of the engaging ridge include a triangle, a trapezoid, a semicircle, and a semi-ellipse, but a curved shape such as a semicircle or a semi-ellipse that makes surface contact with the curved concave surface of the engaging ridge is preferable.

The position (range) of the curved ridge in the engagement insertion portion is preferably 0 to 5 mm, more preferably 1.5 to 4.5 mm from the side edge of the engagement insertion portion. If it exceeds 5 mm, it is difficult for the engaging convex portion to engage with the curved ridge when the tile is laterally displaced.

According to the flat roof tile of the present invention, even if the wind and rain that blows up enter through the gap under the head end of the underlap, it is difficult for water to leak, and it has an excellent effect of being able to cope with a gentle gradient.

FIG. 1 is a perspective view of the surface side of the U-type flat roof tile of the embodiment. FIG. 2 is a perspective view of the back surface side of the flat roof tile. 3A is a rear view, FIG. 3B is a plan view, and FIG. 3C is a front view of the flat roof tile. 4A is a right side view, FIG. 4B is a left side view, and FIG. 4C is a bottom view of the flat roof tile. 5A and 5B are perspective views showing when the flat roof tile is laid, and FIG. 5B is a cross-sectional view taken along the line BB of FIG. 5A. 6 (a) to 6 (c) are cross-sectional views taken along the line AA of FIG. 5 (a) with different working lengths, and FIGS. 6 (d) to 6 (e) are enlarged views of (a). 7 (a) is a perspective view showing the control and damming action of the wind and rain flow by the first to fourth water returns, (b) is an enlarged view of a modified example of the first to fourth water returns, and (c) is a horizontal view. It is a perspective view which shows the damming action of the wind and rain by the water return. 8 (a) to (d) are cross-sectional views, and (e) to (f) are perspective views of modified examples of the horizontal water return. 9 (a) to 9 (b) are perspective views showing the action of damming and returning the wind and rain by the oblique water return, and FIG. 9 (c) is a sectional view taken along the line CC of (b). 10A and 10B show a dampening action of wind and rain by the insertion side portion, the water return extension portion, and the return ridge, FIG. 10A is a perspective view, and FIG. 10B is a plan view. 11A and 11B show a modified example in which a turbulent flow generation groove is provided and its operation, where FIG. 11A is a perspective view and FIG. 11B is a cross-sectional view. 12 (a) to 12 (d) are cross-sectional views showing the action of the engaging ridges. 13A and 13B are a perspective view of the surface side of the conventional U-type flat roof tile (a) and a plan view of the U-type flat roof tile.

A square plate-shaped roof tile body 2 having a substantially flat surface, a stepped hill-shaped overlap 3 higher than the roof tile body 2 on one side of the roof tile body 2, and a roof tile body 2 on the other side of the roof tile body 2. The low underlap 4, the jetty 5 near the underlap between the tile body 2 and the tile body 2, which is higher than the tile body 2, the tail raised portion 6 higher than the tile body 2 on the tail side of the tile body 2, and the tile. It is equipped with a head finder 7 that protrudes downward from the head end of the main body 2, and at the center of the head finder 7 in the width direction, a stepped hill-shaped overlap 3 adjacent to the lower roof tile at the time of roofing and a jetty 5 near the underlap (pier 8). ) In the flat roof tile 1 in which the straddling portion 9 is recessed.
The rising angle of the water-returning surface 22 of the tail-raising part with respect to the surface of the tile body is set to 50 to 87 degrees, and the surface of the tile body is set from the water-returning surface of the tail-raising part located on the outside of the underlap of the upper tile after roofing. An oblique water return 40 was provided.

The flat roof tile 1 of the embodiment shown in FIGS. 1 to 12 (however, FIGS. 7 (b), 8 and 11 are modified examples) is a clay roof tile formed by molding and firing clay, and has a square plate shape. The tile body 2 and the stepped hill-shaped overlap 3 higher than the tile body 2 on one side of the tile body 2, the underlap 4 lower than the tile body 2 on the other side of the tile body 2, and the tile body 2 A jetty 5 near the underlap between the roof tile 4 and the roof tile body 2, a tail raised portion 6 higher than the roof tile body 2 on the roof tile body 2 side, and a protrusion below the head end of the roof tile body 2. It is equipped with a head finder 7, and at the center of the width direction of the head finder 7, a stepped hill-shaped overlap 3 and an underlap vicinity jetty 5 (hereinafter collectively referred to as "pier 8") adjacent to the lower roof tiles at the time of roofing (staggered roof tiles). This is a so-called U-type flat roof tile 1 in which a straddle portion 9 straddling the roof tile 9 is recessed.

At the time of roofing, the terrace-shaped overlap 3 overlaps the underlap 4 to form the ridge 8, and the head of the upper roof tile 7 (excluding the straddle portion 9) is found on the surface of the roof tile body 2 after adjusting the working length. The lower end of the part) comes into contact. Due to this contact, the back surface of the underlap 4 does not come into contact with the upper surface of the bottom raising portion 6 of the lower roof tile. The gap between the upper center side of the straddle portion 9 and the upper surface of the pier 8 (the straddle center gap) is about 3 mm. The gap (crossing lateral gap) between both lateral sides of the straddling portion 9 and both lateral surfaces of the pier 8 is also about 3 mm.

The surface of the roof tile body 2 is substantially flat, and the back surface of the roof tile body 2 is also substantially flat (except for the rib 10 for preventing the tile from twisting in the production process).

The upper surface of the terraced overlap 3 is substantially flat (except for the decorative groove 11), but the portion that is on the head side of the straddle portion 9 of the upper tile at the time of roofing is relatively high, and the straddle portion of the upper tile is relatively high. The part on the buttock side is relatively lower than 9. The inner lateral surface of the terrace-shaped overlap 3 is an inclined surface. A side edge water return 12 is provided near the side edge of the back surface of the terrace-shaped overlap 3.

The upper surface of the jetty 5 near the underlap is substantially flat and narrow (7 mm), and the portion that becomes the head side of the upper tile straddle portion 9 at the time of roofing is relatively higher than the upper tile straddle portion 9. The part on the buttock side is relatively low. The horizontal surface inside the jetty 5 near the underlap is an inclined surface.

On the upper surface of the underlap 4, in the order from the side edge toward the tile body 2, there are an outer water return 14 which is a ridge extending in the flow direction, an outer water channel 15 extending in the flow direction, and a ridge extending in the flow direction. A certain inner water return 16 and an inner water channel 17 extending in the flow direction are provided.

The head side portion of the outer water return 14 is bent and includes an upstream diagonal portion 18 that inclines toward the tile body 2 side, an insertion horizontal portion 19 that extends in the flow direction, and a downstream diagonal portion 20 that inclines toward the side edge side. It is composed. An engaging insertion portion 21 for engaging the engaging convex portion 25 of the lower roof tile is formed on the side edge portion of the underlap 4 on the side of the insertion horizontal portion 19, and the disaster prevention function is fulfilled by this engagement.

Further, since the length of the engaging insertion portion 21 in the flow direction is longer than the length of the engagement convex portion 25 in the flow direction, the engagement position between the engagement insertion portion 21 and the engagement convex portion 25 is shifted. , As shown in FIGS. 6A to 6C, the working length can be adjusted and laid.

The upright surface on the head side of the buttock raising portion 6 is a water return surface 22. A butt sword 23 for hooking on a sword is provided on the back surface of the butt raising portion 6. On the upper surface of the butt-raising portion 6, a butt sword engaging recess 24 for engaging the butt sword 23 of the upper tile when stacking tiles, an engaging convex portion 25 for a disaster prevention function described later, a field ground or a crosspiece A nail hole 26 or the like for nailing to the sword is provided.

The terrace-shaped overlap 3 and the butt-raising portion 6 are connected, the jetty near the underlap and the butt-raising portion 6 are connected, and their upper surfaces are approximately the same height.

The above is a description of the same configuration as the known example of the present embodiment, and the configuration unique to the present embodiment provided for preventing water leakage (corresponding to a gentle gradient) will be described below.

[1] At least on the upper surface of the stepped hill-shaped overlap 3 of the pier 8, the portion that is on the tail side of the straddle portion 9 of the upper tile at the time of roofing, and extends in the left-right direction in order from the head side to the tail side. The 1st water return 31 and the 3rd water return 33 extending in the left-right direction are provided at a distance, and the first water return 31 and the 3rd water return 33 of the lower roof tile are provided on the back surface of the roof tile body 2 at the standard working length. A second water return 32 extending in the left-right direction was provided at a position in between. Further, a fourth water return 34 extending in the left-right direction at a distance from the third water return 33 on the upper surface of at least the terrace-shaped overlap 3 of the pier 8 is provided.

With this configuration, as shown in FIGS. 6 (a), (d), and (e) (standard working length 280 mm (shape “F type 40” defined in JIS A5208)), even in the case of a gentle gradient, the water penetrated through the straddling central gap. The wind and rain are first dammed by the first water return 31 and the flow is turned diagonally upward, then dammed by the second water return 32 and the flow is turned diagonally downward, and then dammed by the third water return 33. .. In this way, the first to third water returns 31 to 33 control and dam the wind and rain so as to meander up and down, so that water leakage from the hips can be prevented. Further, even if there is rainwater that exceeds the third water return 33, it is dammed by the fourth water return 34.

As shown in FIGS. 6 (b) to 6 (c), the working length can be adjusted within an adjustment range of 285 to 260 mm for thatching. This adjustment range is expanded as compared with the conventional case by the configuration of [5] described later. When the roof tiles have a short working length as shown in FIG. 6 (c), the second water return 32 is on the head side of the first water return 31 of the lower roof tile, and the flow of wind and rain is no longer meandering, but the upper and lower roof tiles. The waterproof function is maintained by increasing the overlap of the roof tiles.

The first water return 31 is provided with a terrace-shaped overlap 3 having a left-right length of 47 mm and a width of 8 mm at the hem, and a jetty 5 near the underlap having a left-right length of 7 mm and a width of 8 mm at the hem. The total length is 54 mm (95% of the left-right width (57 mm) of the central upper side of the straddle portion 9). A horizontal water return 38 is formed continuously on the first water return 31. The horizontal water return 38 will be described in detail in the next [2].

The second water return 32 is provided slightly diagonally on the back surface of the roof tile main body 2, and a return ridge 45, which will be described later, is continuously formed therein. The left-right length of the second water return 32 is 100% or more of the left-right width (57 mm) of the central upper side of the straddle portion 9, and the width at the hem is 6 mm.

The third water return 33 is provided on the upper surface of the terrace-shaped overlap 3 with a left-right length of 52 mm and a width of 8 mm at the hem, and is integrated with the tail raising portion 6 on the upper surface of the jetty 5 near the underlap (front and back). Width 27 mm) is provided.

The fourth water return 34 is provided on the upper surface of the terrace-shaped overlap 3 with a left-right length of 38 mm and a width of 9 mm at the hem.

The first water return 31 and the third water return 33 of the terrace-shaped overlap 3 are connected by a connecting ridge 35 on the side edge of the terrace-shaped overlap 3. Therefore, as shown in FIG. 7A, the rainwater that has passed over the first water return 31 is dammed by the connecting ridge 35 and drained toward the roof tile body 2.

The drainage ditch 36 between the third water return 33 and the fourth water return 34 of the terrace-shaped overlap 3 is inclined downward toward the side edge of the terrace-shaped overlap 3, and is opened outward at the side edge. There is. Therefore, as shown in FIG. 7A, the rainwater that has passed over the third water return 33 flows outward through the drainage ditch 36 and is drained to the underlap 4 of the adjacent roof tile through the gap with the adjacent roof tile.

The height of the space between the upper surface of the pier 8 and the back surface of the roof tile body 2 of the upper roof tile (the height of the space on the terrace) M is 5.5 mm, and the height m1 of the first water return 31 is 3 mm (M). Since the height m2 of the second water return 32 is 1 mm (18% of M), m1 + m2 is 73% of M. Further, since the height m3 of the third water return 33 (terrace-shaped overlap 3) is 5 mm (91% of M), there is a relationship of m2 <m1 <m3. The height m4 of the fourth water return 34 is 3 mm (55% of M).

As shown in FIG. 6 (e), the distance from the back surface K of the head finding 7 to the head side hem F of the first water return 31 is 8 mm at the time of standard thatching.
The distance from the tail side hem I of the first water return 31 to the head side hem J of the third water return 33 is 25 mm.

Since the second water return 32 is provided at a slight angle, the front-rear position changes in the length direction, but at the time of standard roofing, the head side hem D and the tail side hem E of the second water return 32 have a length. It is in the range L1 from the head side hem F of the first water return 31 to the head side hem J of the third water return 33 anywhere in the direction, and D is the head side hem F of the first water return 31 at the intermediate position in the length direction. It is at the position of 2/3 point H near the hem on the butt side with the hem I on the butt side (FIG. 6 (e)).

The height and positional relationship of the first to fourth water returns 31 to 34 can be changed as appropriate. FIG. 7B is an example in which the height has a relationship of m1 <m2 <m3.

[2] A horizontal water return 38 extending in the vertical direction is provided on each side surface of the pier 8 at a position on the tail side of the straddling portion 9 of the upper roof tile at the time of roofing.

With this configuration, as shown in FIG. 7 (c), even in the case of a gentle slope, the wind and rain that have infiltrated from the straddling lateral gap is dammed by the horizontal water return 38, and even if a part is overcome, the water return of the tail raising portion 6 is stopped. Since it is dammed by the surface 22, water leakage from the buttocks can be prevented.

The horizontal water return 38 extends from the surface of the roof tile body 2 to at least the upper end of each side surface of the pier 8. The horizontal water return 38 extends laterally from the lower end of each side surface of the pier 8 to the surface of the tile body 2 30 mm laterally away from the lower end.

As shown in FIGS. 5 and 7, the front view shape of the lateral water return 38 extending in the lateral direction has the height of the lateral end extending in the lateral direction (substantially zero). It is a trapezoid that is lower than the height of the base end in contact with each side surface of the mountain 8. The front view shape of the lateral water return 38 on the terrace-shaped overlap 3 side and the front view shape of the horizontal water return 38 on the jetty near the underlap 5 side are substantially symmetrical with respect to the pier 8.

As shown in FIG. 5B, the height N of the space between the front surface of the roof tile body 2 and the back surface of the roof tile body 2 of the upper roof tile is 16.5 mm, and the height n of the horizontal water return 38 (most). The high place) is 15 mm (91% of N).

In this embodiment, the first water return 31 is continuously provided from the upper end of the horizontal water return 38 on each side surface of the pier 8. As a result, the horizontal water return 38 on the terrace-shaped overlap 3 side, the first water return 31, and the horizontal water return 38 on the jetty 5 side near the underlap are lined up side by side at the time of roofing to form an integrated waterproof wall. Configure. Then, even if the wind and rain dammed by the first water return 31 detours sideways and tries to wrap around to the buttock side, it can be dammed by the side water return 38.

At the time of standard thatching, the distance from the back surface of the head finding 7 to the head side hem of the horizontal water return 38 is 8 mm (same as the first water return 31).

[3] The rising angle (angle α in FIG. 9C) of the water-returning surface 22 of the tail raising portion 6 with respect to the surface of the roof tile body 2 is set to 70 degrees, and the roof tile is placed on the outside of the underlap 4 of the upper roof tile after roofing. An oblique water return 40 was provided from the water return surface 22 of the positioned tail raising portion 6 to the surface of the roof tile main body 2.

With this configuration, as shown in FIG. 9, even in the case of a gentle slope, the wind and rain that infiltrates through the gap under the four head ends of the underlap and flows straight to the buttock side is dammed on the way up the water return surface 22 of the buttock raising portion 6. In addition, the wind and rain that infiltrates through the gap under the end of the four underlaps, deviates diagonally outward, and flows toward the buttock side is dammed by the diagonal water return 40 while diagonally climbing the water return surface 22 of the buttock raising portion 6. Therefore, it is possible to prevent water leakage from the buttocks. Further, since the wind and rain dammed by the diagonal water return 40 is returned to the head side by the diagonal water return 40, it does not collect at the corners of the tail raising portion 6 and the jetty near the underlap 5 and can be drained smoothly.

The distance from the side edge of the head side hem of the diagonal water return 40 closest to the side edge of the underlap 4 of the upper roof tile (upper end portion) is 25 mm.
The angle (angle β in FIGS. 3 (b) and 9 (b)) of the head side hem of the oblique water return 40 with respect to the left-right direction is 140 degrees in a plan view.
The width of the upper surface of the oblique water return 40 is 5 to 10 mm, narrow at the bottom and wide at the top.

A notch 43 is formed in the lower part of the head finding 7 on the overlap side, the head end portion of the underlap 4 is made into an inclined portion 41 that inclines diagonally downward, and a protrusion that fits into the notch 43 at the tip of the inclined portion 41. It is preferable to provide the 42 and make the lower surface of the projecting piece 42 slanted so as to rise toward the side end side. The protrusion 42 allows the rainwater flowing through the underlap 4 to be drained to the outside of the roof tile more smoothly, as in Patent Documents 2 and 3.

However, since the projecting piece 42 is thinner than the other parts, it is easily cracked. Therefore, when the worker walks on the roof tile, the lower surface of the projecting piece 42 is set toward the side end so that the projecting piece 42 does not crack due to strong pressure on the lower roof tile, and even if it should crack, it is easy to find. It is preferable to make it an upward slope and let it escape from the lower roof tile. Then, a gap (one aspect of the gap below the end of the four underlaps) that becomes larger toward the side end side is generated between the roof tile main body 2 after the roofing and the projecting piece 42 of the upper roof tile, and the diagonally outward side. There will be more wind and rain flowing to the buttock side.

[4] An outer water return 14 is provided on the side edge of the upper surface of the underlap 4, and the portion of the outer water return 14 near the head side is bent to extend diagonally toward the roof tile body 2 side and in the flow direction. The configuration includes an extending insertion horizontal portion 19 and a downstream diagonal portion 20 extending diagonally to the side edge side, and the engaging convex portion 25 of the lower roof tile is engaged with the side edge portion of the underlap 4 beside the insertion horizontal portion 19. An engaging insertion portion 21 is formed so that the insertion insertion portion 21 is formed, the height of the insertion side portion 19 is set to 7 mm, the head end portion of the underlap 4 is formed as an inclined portion 41 that inclines diagonally downward, and continues from the downstream side oblique portion 20. A water return extension 44 extending in the flow direction is provided on the inclined portion 41, and a return ridge 45 for returning the wind and rain over the outer water return 14 extension to the head side on the back surface of the tile body 2 of the adjacent roof tile. Was provided.

With this configuration, as shown in FIG. 10, even if the drainage from the tail side of the underlap 4 and the wind and rain blown from the head side collide with each other around the insertion side portion 19 of the outer water return 14, this The rainwater that collides with each other does not get over the insertion side portion 19.
Further, if the head end portion of the underlap 4 is set to an inclined portion 41 that inclines diagonally downward, the flow becomes steep in the inclined portion 41, but the wind and rain blown from the head side is an extension of the water return provided in the inclined portion 41. Even if it is dammed by the part 44 and overflows diagonally to the outer buttock side over the water return extension part 44, the overflowing blow will be headed by the return ridge 45 provided on the back surface of the tile body 2 of the adjacent tile on the same stage. Since it is returned to the side, water does not leak to the base.

The tip of the water return extension 44 is 7 mm from the head end of the underlap 4 including the inclined portion 41 and the projecting piece 42.
The height of the return ridge 45 is 2 mm.
The return ridge 45 is continuous with the second ridge, and the second ridge also functions as a part of the return ridge 45. The length of the return ridge 45 including the second ridge is 135 mm.

[5] An outer water return 14 is provided on the side edge of the upper surface of the underlap 4, an inner water return 16 is provided on the inner side, a notch 47 is made in the middle of the inner water return 16, and the head side of the outer water return 14 is provided. The configuration includes an upstream diagonal portion 18 that bends the side portion and extends diagonally toward the roof tile body 2, an insertion horizontal portion 19 that extends in the flow direction, and a downstream diagonal portion 20 that extends diagonally toward the side edge side. An engaging insertion portion 21 for engaging the engaging convex portion 25 of the lower roof tile is formed on the side edge portion of the underlap 4 on the side of the portion 19, and the underlap 4 side of the tail side hem of the upstream diagonal portion 18 is formed. The oblique angle with respect to the edge (angle γ in FIG. 3B) was set to 23 degrees.

With this configuration, the drainage from the tail side of the underlap 4 easily returns to the inside from the notch 47 of the inner water return 16 even if it exceeds the inner water return 16 to the outside, so that the risk of overflow is low. Further, the gentle inclination angle of the upstream side oblique portion 18 makes the drainage smooth and the adjustment range of the working length can be expanded.

[6] A turbulent flow generation groove 51 extending in the left-right direction is provided on the lower surface of the upper center side of the straddle portion 9.

With this configuration, as shown in FIG. 11, when wind and rain pass through the gap between the straddle portion 9 and the pier 8, the turbulent flow generation groove 51 on the lower surface of the straddle portion 9 generates turbulent flow in the wind and rain. Therefore, the momentum of invasion of wind and rain can be suppressed.

The depth of the turbulence generation groove 51 is 1.5 mm. The width of the turbulent flow generation groove 51 is 3 mm. The cross-sectional shape of the turbulent flow generation groove 51 is U-shaped.

[7] An engaging insertion portion 21 for engaging the engaging convex portion 25 of the lower roof tile is formed on the side edge portion of the underlap 4, and the engaging convex portion 25 is provided with a downward curved concave surface 53 to engage. The joint insertion portion 21 is provided with an engaging ridge 54 facing the curved concave surface 53 from below.

With this configuration, as shown in FIG. 12, the intermediate portion (not the tip) of the downward curved concave surface 53 of the engaging convex portion 25 hits the engaging protrusion 54 of the engaging insertion portion 21 in line or in contact with the surface. Therefore, the engaging convex portion 25 is less likely to be damaged. Further, even when the roof tile is lifted diagonally, the engagement between the engaging protrusion 25 and the engaging ridge is difficult to be disengaged.

The width of the engaging ridge 54 is 3 mm. The height of the engaging ridge 54 is 1 mm. The cross-sectional shape of the engaging ridge 54 is a semicircle. The position (range) of the curved ridge in the engaging insertion portion 21 is 1.5 to 4.5 mm from the side edge of the engaging insertion portion 21.

The flat roof tile 1 of this embodiment configured as described above was subjected to a waterproof performance test (Aichi Industrial Science and Technology Center Tokoname Ceramics Technology Center Mikawa Ceramics Testing Center) with a 1.5 inch gradient (rainfall 4 L / m ² min). Passed.

The present invention is not limited to the configuration of the above embodiment, and may be appropriately modified and embodied without departing from the spirit of the invention.

1 Flat plate tile 2 Tile body 3 Stepped hill overlap 4 Underlap 5 Underlap near jetty 6 Bottom raised part 7 Head found 8 Pier 9 Straddle part 14 Outer water return 15 Outer water channel 16 Inner water channel 18 Inner water channel 18 Upstream side diagonal Part 19 Insertion side part 20 Downstream side diagonal part 21 Engagement insertion part 22 Water return surface 25 Engagement convex part 31 1st water return 32 2nd water return 33 3rd water return 34 4th water return 35 Connecting ridge 36 Drain groove 38 Lateral water return 40 Diagonal water return 41 Inclined part 42 Projection piece 43 Notch 44 Water return extension 45 Return protrusion 47 Notch 51 Turbulent flow generation groove 53 Curved concave surface 54 Engagement convex

Claims (4)

A square plate-shaped tile body (1) with a substantially flat surface, a stepped hill-shaped overlap (3) higher than the tile body on one side of the tile body, and a tile body on the other side of the tile body. A low underlap (4), a jetty near the underlap between the tile body and the underlap (5) higher than the tile body, and a raised portion (6) higher than the tile body on the tail side of the tile body. It is equipped with a head finding (7) that protrudes downward from the head end of the tile body, and at the center of the width direction of the head finding, a straddle that straddles the hill-shaped overlap adjacent to the lower tile and the jetty near the underlap at the time of roofing ( In the flat roof tile (1) in which 9) is recessed,
The rising angle of the water-returning surface (22) of the tail-raising part with respect to the surface of the tile body is set to 50 to 87 degrees, and the tile body is formed from the water-returning surface of the tail-raising part located on the outside of the underlap of the upper tile after roofing. A flat roof tile characterized by having an oblique water return (40) over the surface of the roof tile. The flat roof tile according to claim 1, wherein the distance from the side edge of the head side hem of the diagonal water return, which is the closest to the side edge of the underlap of the upper roof tile, is 20 to 40 mm. The flat roof tile according to claim 1 or 2, wherein the angle of the head side hem of the oblique water return with respect to the left-right direction is 90 to 160 degrees in a plan view. A notch (43) is formed at the lower part of the head finding on the overlap side, a protrusion (42) is provided at the head end of the underlap to be fitted into the notch, and the lower surface of the protrusion is obliquely raised toward the side end. The flat roof tile according to claim 1, 2 or 3.

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