KR20170014680A

KR20170014680A - Device for raising Shellfish

Info

Publication number: KR20170014680A
Application number: KR1020150108418A
Authority: KR
Inventors: 이광연; 이하송
Original assignee: 이광연
Priority date: 2015-07-31
Filing date: 2015-07-31
Publication date: 2017-02-08
Also published as: KR101786186B1

Abstract

The present invention provides a device for cultivating an attached organism. The device comprises: a concave and convex cultivating plate in which plate bodies enabling a benthic organism to be attached and grow thereon repeatedly forms a top surface, a side surface, a bottom surface, and another side surface thereof; and a support plate vertically formed with respect to the top surface and the bottom surface thereof in the bottom center of the bottom surface and the top surface, and separating the cultivating plate from the bottom. An attachment area of an attached organism can be remarkably increased, and an area where the bottom of a cultivating water tank comes in contact with a cultivating device is small, so foreign materials such as excretion and residual feeds of a cultivated animal can be easily removed and cleaned. Also, feeds can be evenly distributed in a cultivating water tank when feeds are fed, so entity leaning of cultivating animals can be prevented. Moreover, a cultivation environment having suitable brilliance can be ensured.

Description

Device for raising Shellfish}

More particularly, the present invention relates to an integrated type biological and aquaculture apparatus, and more particularly, to an integrated biological and aquaculture apparatus having an integrated irregular plate and a supporting plate for supporting the same, And to allow the feed to be evenly distributed, thereby improving the feed efficiency of the adhered creature.

Natural catches of marine organisms such as Abalone, Sora, etc., and sea cucumbers have been greatly reduced due to the recent oversupply and contamination of coastal waters. As a result, these marine life technologies have been greatly improved, and they are attracting attention as high value-added fish species.

Abalone is a molluscan animal belonging to the Haliotidae and the Haliotis , and more than 100 species are known worldwide. In Korea, abalone, horse abalone, black abalone, Shiv bolt abalone, pentagonal and obsidian are distributed.

The style of abalone has been made a lot by abandonment or cage cultivation method by discharging large amount of abalone spear or attaching abalone spear to chalony, However, there is a problem that the survival rate of abalone is very low and the harvest is not easy. In addition, there are various problems such as the loss of water due to whitening or typhoons due to contamination of the coastal waters, or the removal of adherent creatures that grow around the shell and are not easy.

The sea cucumbers belonging to the Echinodermata sea cucumbers are mainly found in the inner bottom of the intertidal zone at depths of 20m and on the coastal reefs and pebbles. They are distributed throughout the Northeast Pacific region from the coastal waters of Korea, Japan, Kuril and Sakhalin to one sea area. The sea cucumber, which is called "ginseng of the sea," has a good taste and nourishment.

Sea cucumber cultivation has been carried out in a festive manner in the sea areas where natural seeds or young sea cucumbers are grown over a certain size in aquaculture tanks, followed by development of tidal flats such as the west coast or waters where coastal festivals are possible. In the juvenile sea cucumber or nursery culture, plate type shelters of a certain shape are arranged in the water tank, and a plurality of wave plates are installed on the shelter at predetermined intervals to stand upright with the shelter. Also, the sea cucumber is nocturnal, and in the daytime it is latent at the bottom of the shelter.

Growth is strong at a temperature of 15 ~ 18 ℃, but it rarely feeds when the temperature is high. Therefore, the digestive tract is degenerated, and the domestic coast goes through the summer season when it is warm. In addition to these physiological characteristics, in Korea, the month of July, which is the spawning season, has been designated as a barnyard. Since the change in global climate, irresponsible harvesting and contamination of the coastal sea, ought.

Thus, in order to maximize productivity in the aquaculture of adherent creatures such as abalone and sea cucumbers, it is necessary to (1) increase the ratio of the attachment area to the culture space, (2) (3) to quickly remove wastes and unconsumed food from breeding, and (4) to distribute the food evenly within the aquaculture tank to prevent leaching. In addition, it is necessary to provide shelter of appropriate size according to the growth of adherent organisms, to shorten the moving distance for feeding activity, and to maintain an appropriate amount of illumination to minimize the stress of adherent organisms.

To overcome these problems, abalone farming has attracted attention recently. Terrestrial aquaculture is a kind of filtration of seawater that is drawn from the sea to cultivate in the land. There is no fear of red tide, there is no fear of damage due to typhoons and tsunamis, and it is possible to control water temperature problems such as summer high water temperature and winter low water temperature. Concern can also be reduced.

Therefore, in order to increase the productivity in the aquaculture of adherent creatures such as abalone, sea cucumber, etc., it is necessary to increase the area to which aquaculture creature can be attached, to have a food reservoir, to quickly remove residual food and excrement, It is necessary to develop an apparatus for culturing adherent organisms that can smoothly supply sufficient oxygen and can control the growth conditions of the aquatic organism while uniformly dispersing the feed.

Korean Utility Model Registration No. 20-0333173 discloses a washing machine comprising a main body in which a front plate and a rear plate are integrally formed on both sides of an arc-shaped top plate, A plurality of side insertion grooves formed on the inner surface of the front and rear plates at positions corresponding to the upper insertion grooves and a plurality of side insertion grooves formed at positions corresponding to the upper insertion grooves, Wherein the at least one overturning attachment diaphragm is configured by at least one overturning attachment diaphragm, which is selectively mounted through sliding insertion. Korean Patent Laid-Open Publication No. 10-2014-0056688 discloses a water tank for a sea cucumber and an abalone culturing including a main body, an outlet, an uneven band, and a drainage channel. The main body has a floor space and a wall, Discloses a water tank for sea cucumber and abalone culturing having a slope that discharges debris and waste materials, a plurality of concave-convex strips formed on the bottom of the main body in a rectangular cross-sectional shape, and a drainage channel lower than the bottom surface of the concave-convex strips toward the discharge port. Korean Patent Registration No. 10-0277292 discloses a roof structure comprising a flat roof having a plurality of predetermined holes so that rollover can pass therethrough and a support for supporting the roof, wherein the roof and the support are made of a smooth and opaque material, Characterized in that the roof and the support are attached at right angles so that the roof is kept horizontal and the attachment part of the roof and the support is treated as a smooth surface and the support is formed in two flat plate shapes, For example. Korean Patent Laid-Open Publication No. 10-2014-0096236 discloses an apparatus for supporting a plurality of supports extending vertically and spaced apart from each other, And a ceiling panel having an upper surface formed in a flat shape. However, the above-mentioned inventions have a structure in which a slat-type shelter is provided for the culture of adhered creatures, or a shelter of the same shape is stacked, and a plate-like body having a certain thickness and width, The present invention differs from the apparatus and apparatus of the present invention in that it has a concave-convex plate for repeatedly forming the side surface, the bottom surface, and the side surface to increase the attachment area and provide a suitable illuminance environment .

The present invention was conceived to solve the problems of conventional aquaculture aquaculture devices used in a land-based aquaculture field, and it was found that the aquaculture environment in the aquaculture environment deteriorates due to the irregular feeding of the feed aquatic organisms Which can improve the productivity of the farm and increase the productivity of the farms by greatly increasing the adhering area of the adhered aquaculture organisms and to reduce the feed cost, .

In order to solve the above-described problems, the present invention provides a rough-surfaced plate in which a plate-like body having a certain thickness and width capable of adhering to benthic organisms is formed by repeatedly forming an upper surface, a side surface, a lower surface, And a lower surface support plate is vertically formed at the lower portion with respect to the upper surface and the lower surface at the center of the upper surface and the lower surface and formed vertically with respect to the upper surface and the lower surface at the upper portion of the upper surface and the lower surface, An upper surface supporting plate for separating the aquaculture plate from the floor may be formed so as to separate the aquaculture plate from the floor so as to increase the area to which the attached creature can attach, And a feeding jaw is integrally formed on the upper and lower surfaces to prevent loss of feed.

And an upper surface supporting plate formed on the lower surface of the upper surface supporting plate and a lower surface supporting plate formed on the lower surface of the upper surface supporting plate, And the lower surface support plate formed on the upper surface is formed to be longer than the lower surface support plate formed on the lower surface so that the height of the support plate is the same and the movement groove for horizontally moving the attachment creature is formed on the lower side support plate.

Feeding jaws having protrusions protruding with a predetermined height are formed at regular intervals on the upper and middle portions of the attached biological and aquatic culture apparatus, and a plurality of vertically arranged polygonal plates are stacked on top of the attached biological producing apparatus, Provide an integrated attachment biological aquaculture device that can be mounted on a land aquarium.

As described above, the integrated type biological and aquaculture apparatus disclosed in the present invention comprises an irregular plate that repeatedly forms an upper surface, a side surface, a lower surface, and a side surface, And it is easy to remove and clean foreign materials such as excrement and remaining food of cultured animal because the floor of the aquaculture tank and the contact area of the aquaculture device are small and it is possible to distribute the food evenly inside the aquaculture tank Therefore, it is possible to prevent the aquaculture of the cultured animal from leaning and to form a suitable environment of the culture. In addition, it is possible to increase the productivity of the farm by increasing the space utilization by laminating the present attachment biological aquaculture apparatus.

1 is a top perspective view of an integrated biological and organism producing apparatus according to the present invention.
2 is a top plan view of an integrated attachment biological farming apparatus according to the present invention.
FIG. 3 shows a state where aquatic organisms are attached to the integrated attachment biological aquaculture apparatus according to the present invention.
4 is a side view of an apparatus for adhering biological organisms according to the present invention.
FIG. 5 is a side view showing a side opening of the apparatus for adhering biological organisms according to the present invention. FIG.
FIG. 6 is a perspective view showing a separation part of the apparatus for adhering biological organisms according to the present invention. FIG.
FIG. 7 is a laminate of other attachment plates in the integrated attachment biological farming apparatus according to the present invention.
8 is a photograph showing an outer bottom surface, an inner bottom surface and a side surface portion of a terrestrial water tank capable of accommodating the shelter of the present invention.
Fig. 9 shows a farm where a terrestrial water tank containing the shelter of the present invention is installed.

In the present invention, the ratio of the attachment area of the adhered aquatic organisms in the same space can be greatly increased, while facilitating the communication of the breeding water, facilitating the removal of foreign substances such as feed residue, So as to maximize productivity. 2. Description of the Related Art Hereinafter, the present invention will be described in detail with reference to specific examples.

1 is a top perspective view of an apparatus for adhering biological organisms according to the present invention. The integrated type biological and aquaculture apparatus of the present invention includes a plate body having a predetermined thickness and a width capable of growing and adhering benthic organisms to the upper surface 110, the side surface 120, the lower surface 130, the side surface 120 The upper surface 110 and the lower surface 130 are vertically formed below the upper surface 110 and the lower surface 130 at the lower center of the upper surface 110 and the lower surface 130, And a support plate 200 separating the culture plate 100 from the floor.

The upper surface 110 and the lower surface 130 are vertically formed on the upper surface 110 and the lower surface 130 so as to separate the staging plate from the floor, And the side surface 120 is formed with at least one side through hole 121 through which attached organisms can move. The side surface 120 is formed with at least one side through hole 121, The present invention provides an integrated biosynthetic apparatus that is configured to be spaced apart from a water tank in which an aquaculture apparatus is installed and spaced at a predetermined interval, and a food jaw is formed on the upper and lower surfaces to prevent feed loss and increase feed efficiency.

The culture plate 100 is made of a material having high strength such as acrylic and plastic and capable of moving easily by adhering aquatic organisms. The size of the cultured animal to be breed and the growing speed are determined in consideration of the size of the culture animal. In the embodiment of the present invention, when the overturning spatula is raised, the culture plate 100 has a thickness of 0.1 to 0.5 cm, and the upper plate 110 and the lower plate 130 have a width of 7 to 8 cm and a length of 48 cm The shape of the irregularities of the triangular side and the lower surface is repeatedly formed by 4 to 5 sets. The number of the repeated irregularities can be increased or decreased according to the size of the aquarium.

The through holes 111 are formed regularly in the aquaculture plate 100 to facilitate smooth communication of the aquaculture water. When the aquatic and aquatic aquaculture apparatus according to the present invention is placed on the aquaculture tank, To prevent the bottom of the culture plate from remaining.

The culture plate 100 is separated from the bottom by the support plate 200 which is perpendicular to the culture plate 100. At this time, the upper surface support plate 210 is formed higher than the lower surface support plate 220 so that the lower surface of the upper surface support plate 210 and the lower surface support plate 220 are arranged in a straight line, A moving groove for horizontally moving the creature is formed and is movable to the upper and lower portions via the side through holes so that the forming plate 100 as a whole is leveled.

In addition, since the support plate 200 is formed perpendicular to the ground, the area of contact with the bottom of the attached biological aquaculture apparatus can be minimized, thereby allowing the aquaculture organism to be cultured away from contaminants such as waste accumulated on the bottom of the tank.

Removing from the Aquaculture tank as soon as possible is a major factor in aggravating the aquaculture environment of the aquaculture animal that is immersed on the bottom of the aquaculture and the food remaining after ingestion. When the conventional shelter is used, the area where the shelter touches the aquaculture tank is large or the bottom of the shelter has a certain angle and the foreign material is deposited between the shelter and the aquaculture tank bottom while contacting with the bottom of the aquaculture tank.

Especially, when the aquaculture is being cultivated, it is difficult to completely remove the foreign matter by circulation of the water, or by the water spray alone. However, the adhered biological and aquaculture apparatus disclosed in the present invention is such that the bottom surface of the breeding tank and the support plate 200 are in contact with each other at right angles, and the contact area is small so that foreign matter can be effectively removed.

2 is a top plan view of an apparatus for adhering biological organisms according to the present invention. Since the top plate 110, the side plate 120, the bottom plate 130, and the side plate 120 are formed at regular angles and are repeatedly formed, Maximizing the surface that can be attached to the adhered aquatic organisms in a limited space.

Therefore, when the feed is fed, the feed is seated on the upper surface 110 and the lower surface 130 which are parallel to the ground surface. However, as shown in FIG. 3, Not only can it be attached to the lower surface 130 but also it can be attached to the attachment plate 300 formed vertically to the plane, so that the space can be efficiently utilized. An increase in the area of attachment can greatly improve the aquaculture environment, since even aquaculture of the same number of aquaculture organisms can be dispersed and adhered to a wider area.

4 is a side view of an apparatus for adhering biological organisms according to the present invention. A support plate 200 is vertically attached to the bottom of the culture plate 100 to separate the culture plate from the bottom of the water tank while an attachment plate 300 is provided on the culture plate 100 at a position corresponding to the support plate 200 And is formed perpendicular to the culture plate 100 to increase the surface to which the adhered aquatic organism can attach. The upper surface support plate 210 is formed to be higher than the lower surface support plate 220 so that the upper surface attachment plate 310 is formed on the lower surface 130, Is formed to be shorter than the lower surface attachment plate 320 so that the positions of the upper ends of the attachment plates are formed in a line.

With this configuration, the upper and lower portions of the apparatus for maintaining and maintaining an attached biological organism of the present invention can be maintained in a horizontal state when another wafers are stacked on top of the attached biological aquaculture apparatus. In addition, grooves having a predetermined size spaced apart from the floor are formed at the center of the lower surface support plate so that benthic organisms distributed on the bottom of the water tank can move across the plate when the lower surface support plate touches the bottom of the water tank.

In the case where a groove is not formed in the lower surface support plate, the benthic organisms moved to the bottom are inhabited in a limited space, and the efficiency of the space is lowered, and seawater flow is blocked to prevent water pollution such as free oxygen. The attachment plate 300 not only increases the attachment area of the adhered aquatic organisms, but also contributes to the even distribution of the feed and the prevention of seizure and loss of the feed along with the feed jaw 400 when the feed is fed, In addition, it is possible to reduce the stress of the aquaculture by forming the appropriate shade in the aquaculture system during the day so as to be able to do.

In an embodiment of the present invention, the upper surface support plate 210 is 8 to 10 cm and the lower surface support plate 220 is 4 to 5 cm. The upper surface attachment plate 310 is 1 to 2 cm, (320) was fabricated at 4 to 5 cm. The distance between the support plates 200 is 7 to 8 cm, which is equal to the width of the upper surface 110 or the lower surface 130.

5 is a side view showing a side through hole 121 of the apparatus for attaching and detaching biological organisms according to the present invention. The side surface 120 of the culture plate 100 connects the upper surface 110 and the lower surface 130 and at the same time becomes a passage through which food can be accessed by aquaculture. Side side air holes 121 are formed in the side surface 120 so that the lower and upper portions of the aquaplanes 100 can communicate with each other, Can freely move.

Therefore, when the feeding is completed, the aquatic organisms that have been fed to the upper and lower surfaces 110 and 130 are moved to the lower part of the aquarium 100 through the side through holes 121 to stay in the lower favorable area . As a result of the side through holes 121, the adhering aquatic organisms can adhere to the top of the culture plate 100, the top and bottom surfaces of the support plate 200, and the both surfaces of the attachment plate 300 So that the mounting area is significantly increased.

In addition, the side through holes may be formed in such a manner that a side through-hole having a side through-hole size is connected to the side surface and the lower plate is opened on the back surface of the side surface, Since most of the adhered aquatic organisms are nocturnal, the aquaculture organism can easily live in the shade through the side through holes 121, and the lower space of the aquarium plate 100 formed by the shade can be widened, Increase productivity by reducing stress on aquatic organisms by giving them a sense of stability

The side through holes 121 also allow the aquaculture to communicate sufficiently with the upper and lower portions of the attachment biological aquaculture apparatus of the present invention, thereby enabling rapid processing of the aquatic products such as waste products of the aquaculture and feedstuffs , Thus preventing the aquaculture environment from deteriorating within the aquaculture tank. Also, when cleaning the water spray, the washed water on the upper surface 110 and the lower surface 130 collides with the side surface 120 and flows to the side through-hole 121 to be easily cleaned. The size of the lateral perforations may vary depending on the size of the aquaculture. In one embodiment of the present invention, a perforation having a height of 3 cm and a width of 6 cm is formed around the abalone.

6 is a perspective view showing a separation part 112 of the apparatus for adhering biological aquaria according to the present invention. When the adhering biological aquaculture apparatus according to the present invention is put on the aquaculture tank, the edge of the aquaculture apparatus can come into contact with the wall of the aquaculture tank due to the flow of the aquaculture water or the bubbling. At this time, there is a possibility that the young aquatic organisms may be drowned in the aquaculture apparatus and the aquaculture tank, or the shell may be broken. In order to prevent this, a part of the central part of the upper surface 110 of the culture plate 100 is protruded to the left and right so as to form a separation part 112 which can be positioned so as to be spaced apart from the wall surface of the water tank, A space is formed by the protruding portion of the spacing portion 112 even if it contacts with the wall surface, thereby preventing damage to aquatic organisms such as spots and gills.

When feeding the adherend creature, the feed is located on the upper surface 110 and the lower surface 130. The feed jaw 400 is formed on the upper surface 110 and the lower surface 130, It prevents flow down and loss. The feeding jaws are formed at regular intervals on the upper surface edge of the culture plate with a predetermined length.

In addition to the attachment area and roughness, the phenomenon of the farming of the aquaculture in the aquaculture tank is also related to the productivity of the farm. For example, when a feed is fed, if the feed is not evenly distributed in the aquarium but is pushed to one side, the aquatic creature is also driven to one side. In this case, the environment in the aquarium may be partially worsened. In addition, individuals with easy access to food are more favorable to growth, so even if they grow in the same aquaculture, they will show differences in growth rates, which will inevitably lead to a decline in productivity compared to farms with uniform growth rates.

Since the conventional shelter is often composed of slate type wafers, it is often difficult to distribute evenly throughout the aquaculture tank because the food is often poured into the fragments of the bones at the time of feeding. However, the adhered biological and aquaculture apparatus disclosed in the present invention is advantageous in controlling the density of an individual because the food is seated on the upper surface 110 and the lower surface 130 when the food is fed, In addition, since the food jaws 400 are formed, the food placed on the upper surface 110 and the lower surface 130 does not flow to the floor, but remains in a position where access to the aquatic organism is easier than the general shelter. .

As shown in FIG. 7, after the apparatus for adhering biological aquaculture according to the present invention is placed in the aquaculture tank, another attached biological aquaculture apparatus or another shelter can be stacked on the top. The crossing arrangement of the attachment biological aquaculture device can achieve a space where the attachment area is drastically widened and sufficient food activity can be secured. In addition, it is possible to form an environment that maximizes the utilization of space in a limited land breeding place .

8 is a photograph showing an outer bottom surface, an inner bottom surface and a side surface portion of a terrestrial water tank capable of accommodating the shelter of the present invention. The aquaculture water tank has a height and a length which are open in the upward direction, square in the front, rear, left and right direction, and have a height of a certain distance in the longitudinal direction on the side wall and formed as a " , A concave / convex portion for reinforcing the sidewall is formed around the upper surface of the side wall, and a trapezoidal concavo-convex portion and a triangular concavo-convex portion having a flat upper surface are provided in the longitudinal direction. In the case of the conventional rectangular shape, By constructing a separate square instead of a rectangle, it is possible to breed individual sizes.

However, when the longevity tank is separated into the square water tank as shown in FIG. 9 and the attached organisms are raised, the growth environment can be established for each water tank, and the feeding rate according to the growing condition can be controlled differently. In addition, in the case of the feed water feeding system, as the food flows in the direction of the drainage according to the water flow of the replenishing water of the feeding water, the adherent organisms are attracted to prevent the phenomenon that the density of a part of the feeding water increases. In particular, when the aquaculture tank is small, as shown in FIG. 9, it is possible to expect an increase in income by increasing the individual density and increasing the growth rate according to the increased attachment area using the laminating method.

The aquarium apparatus frame of the present invention can be manufactured through injection molding using an arm frame frame and a male frame frame. Injection molding refers to a method of molding a material (injection molding) by molding it into a hopper, dissolving it in a hopper, applying appropriate pressure, and pushing it into a mold (frame) It is the method of production.

The arm frame frame is a frame having a groove like the formatter device frame of the present invention, and several frames can be fixed by grooving the arm frame. On the side of each frame frame, an injection hole is formed to inject injection material from the outside, and the injection material is injected into the frame frame by fusing the injection material at high temperature and high pressure.

The injection material to be injected in the molding process of the present invention may be an engineering plastic such as recycled plastic, polyamide, polyacetal, polycarbonate, polyphenylene oxide, polybutylene terephthalate, high density polyethylene, vinyl chloride, ), And the aquarium frame of the present invention can be manufactured by causing the melt to harden.

The adhered biological aquaculture apparatus disclosed in the present invention comprises an irregular aquaculture plate to which attached organisms can attach and a supporting plate capable of supporting the irrigated aquarium, thereby greatly increasing the area of attachment of the aquatic organism, facilitating cleaning, The present invention relates to an adhesive biological aquaculture apparatus which improves the productivity of aquacultural organisms by enhancing the productivity of aquacultural aquaculture. .

100: plate plate 110: upper surface 111: through hole
112: spacing part 120: side surface 121: side through hole
130: lower surface 200: support plate 210: upper surface support plate
220: lower surface supporting plate 300: attachment plate 310: upper surface attachment plate
320: lower surface attachment plate 400: feeding jaw

Claims

And a flat plate having a predetermined thickness and a width to which benthos can attach and grow, is composed of a top plate, a concave-convex plate connected to the side plate and the bottom plate, and repeatedly connected to the side plate,
An upper surface attachment plate and a lower surface attachment plate perpendicular to the upper surface and the lower surface are formed at an upper center of the upper surface and the lower surface,
The upper surface supporting plate and the lower surface supporting plate are formed vertically with respect to the upper surface and the lower surface at the lower part of the upper surface and the lower surface so that the staging plate is spaced from the floor so that the area In addition,
Wherein one or more through holes through which attached organisms can move are formed on the side surface and a feeding jaw is integrally formed on an upper edge and a central portion of the upper surface and the lower surface to prevent loss of fed feed. Integrated attachment bioreactor.

[2] The apparatus according to claim 1, wherein spaced apart portions protruding outward from the culture plate are formed at the front end and the rear end of the upper surface,

[3] The apparatus of claim 2, wherein the upper surface support plate formed on the lower surface is longer than the upper surface support plate formed on the upper surface, and the lower surface support plate formed on the upper surface is formed longer than the lower surface support plate formed on the lower surface, And a movable groove for horizontally moving the attached organism is formed on the lower side support plate.

[4] The apparatus according to claim 3, wherein a plurality of vertically arranged polygonal plates are stacked on top of the attached biological and aquatic apparatus,

[5] The apparatus according to claim 4, wherein the aquaculture water tank has a height and a length that are open in the upward direction and square in the front, rear, left, and right directions and have a height of a predetermined distance in the longitudinal direction on the side wall, Wherein a concave / convex portion for reinforcing the side wall is formed around the upper surface of the side wall, and a trapezoidal convex / concave portion and a triangular concave / convex portion having a flat upper surface are provided on the bottom in the longitudinal direction.