JP3576864B2 - Method for producing concrete product and concrete product - Google Patents

Description

[0001]
[Industrial applications]
The present invention relates to a concrete product manufactured by using a durable formwork in a factory or a site, and a method for manufacturing the same.
[0002]
[Prior art]
FIG. 14 shows how a concrete basin such as a handhole is manufactured. These concrete basins are often so-called precast concrete products, which use standardized products of a predetermined size and are prepared before embedding at a factory or a site. Therefore, the mold is also formed of an iron plate or the like, and can be used repeatedly.
[0003]
FIG. 14 shows a state in which a concrete mold is manufactured using a decomposable mold as an inner mold that defines the inner surface of the concrete basin. On the base 1, the outer formwork 2 and the assembled inner formwork 3 are installed. The inner frame 3 is composed of a bottom frame 3a defining a bottom surface and a side frame 3b defining a side surface, and the side frame 3b is divided into a plurality. The divided side frames 3b are connected by a turnbuckle 4. As shown in FIG. 14A, concrete 8 is cast between the assembled inner mold 3 and outer mold 2, and the pit 10 is manufactured.
[0004]
Next, as shown in FIG. 14 (b), an operation of removing the inner mold 3, the outer mold 2, and the base 1 from the concrete box 10 is performed. In FIG. 14 (b), first, the base 1 and the outer formwork 2 are removed from the concrete basin 10 formed in FIG. 14 (a). Next, in order to remove the inner mold 3, the concrete basin 10 formed in a prone state is inverted by a crane or the like. After that, the inner mold 3 is disassembled using the turnbuckle 4 and the hook 5 attached to the bottom frame 3a, and is removed from the concrete basin 10.
[0005]
[Problems to be solved by the invention]
When such a form is used, in order to remove the inner form 3, an operation of inverting a heavy concrete basin 10 weighing several tons is required in some cases. Further, every time a concrete basin is manufactured, an operation of disassembling and assembling the inner mold is required.
[0006]
Therefore, it is an object of the present invention to provide a concrete product manufacturing method and a concrete product that do not require the concrete basin to be inverted, and can save the labor of disassembling and assembling the inner formwork.
[0007]
[Means for Solving the Problems]
Therefore, in the present invention, a concrete basin is formed using an inner mold having a tapered side surface. Then, a hanging hook is buried on the back surface of the bottom surface. Since the side surface is tapered, the inner form can be removed by lifting the concrete basin using the hanging hook attached to the bottom of the concrete basin. Therefore, it is not necessary to invert the concrete basin, and it is possible to save the labor of disassembling and assembling the inner mold.
[0008]
Even when such a tapered form is used, when the inner form is in close contact with the concrete basin, impact such as hitting the inner form with a hammer while the concrete basin is lifted up It is desirable to use. It is also effective to provide an air hole in the bottom frame of the inner mold to make it easier to remove the mold. According to this method, the impact given to the mold when removing the mold can be reduced.Further, by introducing air from the concrete product side to the interface with the formwork, it is possible to prevent the path from being clogged by the sluggishness.
[0009]
In addition, the hanging hook buried in the back of the bottom surface of the concrete product can be used for removing the formwork, can also be used for transporting the concrete product, and can be easily cut when it becomes unnecessary .
[0010]
If compressed air is injected into the interface between the concrete basin and the formwork to release the close contact between the formwork and the concrete product, the removal of the formwork becomes easier, and the impact on the formwork during the initial stage of removal is reduced. Can be. Furthermore, since there is no vacuum between the mold and the concrete product when the mold is removed, the mold can be removed smoothly even after the close contact between the mold and the concrete product is once released. However, the gap between the concrete product and the formwork where compressed air first enters is very small, and if this gap expands smoothly and compressed air does not enter over a considerable area of the boundary surface between the concrete product and the formwork. Concrete products cannot be pushed up against the formwork. Therefore, it may still be necessary to take measures such as giving an impact to the formwork to widen the gap.
[0011]
On the other hand, it is also conceivable that a rubber mat or the like is interposed between the concrete product and the formwork, and air is introduced from the side of the formwork below the rubber mat to secure an area where air pressure acts at the beginning of demolding. However, as long as almost all surfaces between the concrete product and the formwork are not covered with the rubber mat, a concrete slack (a cement paste or grout-like material) is formed in the gap between the rubber mat and the formwork when casting concrete. Cement) and the gap gradually fills up. When concrete is poured into a formwork and then vibrated with a vibrator or the like, paste-like concrete like a sludge penetrates into narrow gaps. In the case where compressed air is supplied from an air hole or the like formed in a mold, if a gap that allows compressed air to be supplied due to a slack is reduced, a force for pushing up the mold by the compressed air can hardly be expected.
[0012]
If the air holes for supplying such air and the space between the mat and the formwork are cleaned each time a concrete product is formed, the frequency of occurrence of the above-mentioned problems caused by clogging of the filter can be reduced. However, it takes time to clean, and even if cleaning is repeated, the durable formwork gradually accumulates in the gaps each time it is used, and the gaps are reduced and clogged easily. It will be difficult. Therefore, in the above-described method, the demolding work cannot be performed by taking advantage of the effect of the compressed air constantly, and in some cases, the demolding can be smoothly performed, or the effect of the compressed air cannot be seen at all. It may not be possible to remove the mold without giving vibration to it. If stable demolding work cannot be performed, it becomes difficult to manage the process in the factory, and it will be difficult for hard workers. Furthermore, if stable demolding work cannot be performed using air pressure, it is necessary to provide a relatively large taper to the mold, or it may be necessary to use an inner mold that can be disassembled.
[0013]
Therefore, when manufacturing concrete such as a concrete basin, the production method that enables the demolding work to be easily performed in a short time by stably exerting the effect of demolding with compressed fluid such as compressed air, concrete products and It is desirable to provide a suitable insert or formwork. Further, it is desirable to provide a manufacturing method capable of supplying a concrete product with good volumetric efficiency by always enabling smooth demolding even with a mold having a small taper by using air pressure or the like. Further, it is desirable that the mold can be removed without giving an unreasonable impact to the durable mold to prevent damage to the mold and prolong the life of the mold. It is also desirable to reduce the labor of workers involved in the production of concrete products, improve work efficiency, and provide inexpensive concrete products.
[0014]
In addition, the manufacturing method as described above can be used using a simple-structured formwork, minimizing the cause of failure and enabling stable and efficient work, thereby reducing the burden on workers. It is desirable to do.
[0015]
Therefore, first, in the method for manufacturing a concrete product using the durable formwork of the present invention, a curing step of forming a path capable of supplying a compressed fluid to the inside of the concrete product cured in the formwork, When the frame is removed, it is desirable to adopt a demolding step of introducing a compressed fluid through the path to the interface between the mold and the concrete product.
[0016]
According to such a manufacturing method, if a path for supplying a compressed fluid such as compressed air is provided on the concrete product side, the compressed fluid is introduced into the boundary between the formwork and the concrete product at the time of demolding, and the formwork is introduced. Concrete can be peeled off smoothly from If a path for supplying the compressed fluid to the concrete product side is formed instead of the formwork, the concrete product will be located above the normal formwork, especially the inner formwork which is problematic during demolding. For this reason, the ladle generated during the manufacture of the concrete product rarely flows into the fluid path, and the launder does not block the path.
[0017]
Further, if a path is provided on the concrete product side, a new fluid path is formed each time a concrete product is manufactured. Therefore, slack is not accumulated in the path for supplying the fluid, and the fluid can always be supplied using the new path, so that the demolding operation using compressed air or the like can be stably performed. For this reason, the degree of taper of the mold may be reduced, and a concrete product having good volumetric efficiency can be efficiently and stably manufactured. In addition, it is not necessary to apply a shock such as vibration to the mold at the beginning of the demolding operation, the life of the mold can be extended, and the load on the operator can be reduced. Further, since the path for supplying the compressed fluid is constantly updated, the trouble of cleaning this path can be omitted.
[0018]
Further, if a path for the compressed fluid is prepared on the side of the concrete product, the concrete product is formed above the inner form defining the inner surface thereof. Therefore, if the inner formwork below the concrete product is lifted together with the concrete product prior to the demolding step, the own amount of the inner formwork acts in a direction to separate from the concrete product. For this reason, even if the area of the gap between the inner mold and the concrete product that can supply the compressed fluid at the initial stage of demolding and the concrete product is small, and even if the peeling force is weak with only the compressed fluid, the inner mold has its own amount. The gap is widened by the synergistic effect of the above, and a smooth demolding operation can be performed by effectively using the pressure of the compressed fluid. In addition, if such a method is adopted, the inner mold is detached from the concrete product downward, and the manufactured concrete product can be transported in a suspended state, so that the demolding operation and the transport operation can be performed as a series of flows. There are also benefits.
[0019]
In order to form such a path in a concrete product, a pipe such as a pipe may be embedded in the concrete product. For example, a substantially cylindrical insert having both open ends may be installed in advance on the surface of the formwork and embedded so as to penetrate the concrete product. In particular, in the case of a cylindrical concrete product having a bottom surface or an upper surface, the above-described insert may be embedded in the bottom surface or the upper surface. Since the concrete product is molded outside the inner mold that defines the concrete product of such a shape, fluid such as compressed air is used not from the inside of the inner mold but from the outside using an insert embedded in the concrete product. Can be supplied to the interface with the mold. Accordingly, since the hose serving as the supply source of compressed air can be attached and detached from the outside, the operation is simple and no complicated mechanism is required. Of course, the same applies to not only the cylindrical shape but also the shape of the U-shaped groove and the like. If the compressed fluid can be guided to the boundary between the concrete product and the formwork by the above-described insert or the like, when the product is manufactured, Since the compressed fluid can be supplied from the concrete product side exposed to the outside, the demolding operation can be performed easily and stably.
[0020]
Such a fluid introduction path can also be formed using concrete itself with a paper sleeve or the like. It can also be formed by penetrating a resin or metal concrete product such as plastic and embedding an insert having a substantially cylindrical shape and open at both ends. Of course, the inside of the insert may be filled with concrete or the like after demolding.
[0021]
A liquid such as water can be used as the compressed fluid, but a gas is desirable in consideration of the expansion coefficient and ease of handling in factories and the like, and compressed air is convenient.
[0022]
In addition, considering the connection with the compressed air source, the setting to the mold, the behavior, and the shape that guides compressed air etc. to the gap with the mold, the material such as plastic, vinyl chloride, other resin, etc. It is desirable to embed an insert formed in a predetermined shape in advance to form a fluid path. For example, when the end set toward the mold of the insert is the first end, it is preferable that a flange surface is provided at the first end to make contact with the mold. The flange surface may be any surface as long as it can form a surface or a space extending outward with respect to the substantially cylindrical insert main body. If the flange surface is in contact with the surface of the mold, the contact area with the mold can be increased as compared with the case where the insert body is simply brought into contact with the mold. As a result, the area where the pressure acts at the beginning of the introduction of the compressed air or the like can be increased, so that the separation from the mold can be performed smoothly. Also, since the area for sealing the back of the concrete increases, the gap into which the compressed fluid enters can be increased also in that point. Further, the flange surface has a function of stabilizing the setting state of the insert.
[0023]
It is also possible that the second end of the insert, opposite the first end, can be connected and secured to a source of compressed fluid. The insert may be set by hand with a flexible hose or the like, which is a supply source of compressed fluid supplied from the outside. However, it is safe if the supply source can be fixed to the insert. The lowering work can be performed simultaneously and safely. Of course, it may be one that can fix a cylinder or the like.
[0024]
As a means for attaching and detaching a hose or the like, a type in which a projection is provided at the tip of the hose, which is inserted into the second end of the insert and turned by a predetermined angle, and which is connected is convenient when considering attachment and detachment. If a protrusion or the like is provided at the second end to support the angle at which the hose can be attached and detached, the hose and the like can be securely attached and detached, and compressed air is supplied even when the hose is not connected. Can be prevented beforehand.
[0025]
Further, at least one of the first and second ends may be provided with a means for closing the insert, such as a bolt, joint, or cap. This is because when burying a concrete product at a site, it is desirable to prevent the intrusion of earth and sand or groundwater. Naturally, concrete may be filled with inserts, or the insert may be covered with another concrete product. When the concrete product is a basin having a bottom, the insert can also be used as a drain for draining drain generated inside the concrete product.
[0026]
In some cases, the length of such an insert does not completely match the wall thickness of the concrete product. In such a case, the end of the insert protruding from the concrete wall surface may be pushed and the insert may come off the concrete product. For this reason, a projecting portion may be provided on the outer peripheral surface of the insert body to increase the adhesive force between the insert and the concrete product. Further, the projecting portion may be turned into a flange shape around the outer peripheral surface of the insert main body to have a function as a water stop plate.
[0027]
The wall thickness of concrete products varies, and it is of course possible to prepare inserts of corresponding lengths. However, inserts corresponding to thin wall thickness and connectable to the second end of the insert are available. An insert for extension may be prepared. If one or two or more extension inserts are connected according to the wall thickness, only two types of base inserts and extension inserts are required, and concrete with various wall thicknesses can be prepared. Can respond to products. As a result, labor saving in inventory management at the factory and reduction in insert manufacturing cost can be achieved.
[0028]
In addition, if a port that can be connected to the supply source of the compressed fluid is provided on the side opposite to the coupling end of the extension insert, the above-described safe operation can be performed in a state where the extension insert is overlapped. . It is also desirable to provide a means for indicating the angle of attachment and detachment on the side of the connection port of the extension insert.
[0029]
Such inserts must be mounted on a formwork so that fluid can be supplied through the interior of the insert. Therefore, at least a part of the inner surface of the insert according to the present invention is provided with a projection capable of holding the insert by sandwiching a substantially columnar support member protruding from the mold. By using this insert, a gap can be formed between the support member of the mold and the protrusion protruding from the insert, so that the compressed fluid can be guided to the interface between the mold and the insert via this gap.
[0030]
Conversely, from the surface of the mold, the outer peripheral side surface of the substantially columnar support member protruding so that the substantially cylindrical insert can be fitted therein is expanded in the outer peripheral direction so that a part thereof presses the inner surface of the insert. Is also good. This can also provide a gap for guiding the fluid inside the insert.
[0031]
Furthermore, a screw hole may be provided on the surface of the mold, and a pressure-resistant box may be formed on the back surface of the mold opposite to the surface of the screw hole. After inserting a bolt inserted from the surface side of the mold so as to penetrate the insert through the screw hole and fixing the insert, concrete is poured to form a concrete product. Then, if the fluid is introduced into the insert after the bolt is removed, there is a pressure-resistant box on the opposite side of the screw hole, so that the fluid is supplied to the interface between the insert and the mold without leaking. Since the concrete box may leak into the pressure-resistant box, an opening / closing unit for cleaning may be provided.
[0032]
【Example】
An embodiment according to the present invention will be described below with reference to the drawings.
[0033]
First, as shown in FIG. 15, a concrete basin 10 is formed using the inner mold frame 6 whose side surface 6 b is tapered. In this case, since the side surface 6b is tapered, the inner mold 6 can be removed by lifting the concrete basin 10 using the hook 9 attached to the bottom of the concrete basin 10. Therefore, it is not necessary to invert the concrete basin 10 and it is possible to save the trouble of disassembling and assembling the inner mold.
[0034]
Even when such a tapered form is used, since the inner form is in close contact with the concrete measure, it is difficult to remove the inner form 6 by simply lifting the concrete measure 10. In a state where the concrete basin 10 is lifted, the inner mold 6 is often removed by using an impact such as hitting with a hammer 11. Also, a method of providing an air hole in the bottom frame 6a of the inner mold frame 6 has been proposed to make the mold frame easy to remove. According to this method, the impact given to the mold when removing the mold can be reduced. Further, in order to reduce the load on the worker and the impact on the formwork, and to reduce the degree of taper provided in the formwork and to manufacture a concrete basin having a high volumetric efficiency, the concrete form is provided in the formwork as described above. There is also a method of injecting compressed air from an air hole and pushing up the concrete basin by air pressure from the lower side at the time of demolding.
[0035]
Further, FIGS. 1 and 2 show a concrete handhole used for embedding an electric wire as a concrete product according to the present invention. The hand hole 20 is a substantially rectangular parallelepiped concrete molding buried in the ground, and is buried at the start point, the end point, the corner, and the like of a route for burying an electric wire, and is buried through the wall of the hand hole 20. An electric wire can be laid via an electric conduit. The handhole 20 of this example is formed from two upper and lower parts, that is, an upper part 21 and a lower part 31. The upper portion 21 of the handhole 20 has a rectangular cylindrical shape with an open end on the lower side, and is formed by four side surfaces 22 and an upper surface 23. The upper surface 23 is formed with an opening 24 so that a hand or a person can enter and exit, and an introduction hole 25 for introducing air during manufacturing. The introduction hole 25 is formed so as to penetrate a concrete wall constituting the upper surface 23. In this example, in order to form the introduction hole 25, an insert 26 using a small-diameter pipe made of PVC (vinyl chloride) is embedded in a concrete wall.
[0036]
The lower part 31 has a rectangular cylindrical shape with an open end at the upper part, and is formed by four side surfaces 32 and a bottom surface 33. The bottom surface 33 is provided with a recess 34 for collecting the inflowing underground water and the like. Further, an introduction hole 35 having a function of discharging drainage such as groundwater accumulated in the depression 34 and a function of introducing air at the time of manufacturing is formed substantially at the center of the depression 34. The introduction hole 35 is formed so as to penetrate the concrete wall constituting the bottom surface 33, similarly to the introduction hole 25 formed on the upper surface. The introduction hole 35 formed in the bottom surface 33 is also formed by embedding an insert 36 in a concrete wall using a small-diameter pipe made of PVC. Further, a water stop bolt 37 can be installed in the introduction hole 35 in case the groundwater level at the time of burial is high. The technique of providing a through hole for drainage on the bottom surface of the handhole 20 and the like to open and close the through hole depending on the groundwater level is described in detail in the Utility Model Registration Application No. 4-43805 “Underground Line Box” by the present applicant. It has been disclosed. That is, when the groundwater level is high, it is necessary to close the insert 36 in order to prevent groundwater intrusion, but when the groundwater level is low, the drain 36 generated in the handhole can be reduced by keeping the insert 36 open. It can be discharged automatically.
[0037]
3 to 7 show a method of manufacturing the handhole 20 according to the present embodiment. Since the manufacturing method is the same for the upper portion 21 and the lower portion 31, the lower portion 31 will be described below. First, as shown in FIG. 3, a rectangular parallelepiped inner mold 40 is placed on the base 1, and the outer mold 2 is assembled outside the inner mold 40. On the upper surface 41 of the inner mold frame 40, a convex portion 42 is formed, which forms a depression in the lower portion 31, which is gently projected toward the surface above the inner mold frame 40. These molds are made of an iron plate for durability, so that concrete products having the same shape can be repeatedly manufactured.
[0038]
A screw hole 60 is formed substantially at the center of the convex portion 42, and a pressure-resistant box 61 is formed on the back side below the inner mold frame 40. The pressure-resistant box 61 is formed of a generally cylindrical pipe having a conical shape at the bottom. The tip of the conical portion is sealed with a bolt 62 so that the pressure resistance of the box 61 on the form side can be maintained. The bolt 62 is attached so that the slack of the concrete that has entered the inside of the pressure-resistant box 61 can be removed.
[0039]
The insert 36 forming the introduction hole 35 is placed on the screw hole 60, and a long bolt 65 is inserted from above the insert 36. The bolt 65 is fixed by a screw hole 60 after penetrating the insert 36. As a result, the insert 36 can be fixed to the mold 40.
[0040]
Next, as shown in FIG. 4, concrete 8 is cast into a space defined by the base 1, the outer mold 2 and the inner mold 40, and the lower part 31 is manufactured. At this time, a hanging hook 39 is embedded in the back surface 38 of the bottom surface 33 of the lower part 31. The hanging hook 39 is used when removing a formwork described later. The hanging hooks 39 can also be used to carry this concrete product, and can be easily cut when no longer needed.
[0041]
When pouring the concrete 8 between the formwork, care must be taken that the concrete 8 does not enter the interior of the insert 36. Since the insert 36 of this example is set from the outside of the inner mold 40 by the bolt 65, it is set to the mold with the opening above the insert 36 closed by the head of the bolt 65. Accordingly, since concrete 8 does not enter the inside of the insert 36, there is no need to pay attention so that concrete does not enter the inside of the insert during the work, and the concrete pouring operation can be performed quickly and reliably. Furthermore, since the insert 36 is set to be on the upper side with respect to the inner mold 40, even if a vibrator or the like is run, the slack does not enter the inside of the insert 36 and does not accumulate inside the insert 36. . Therefore, as will be described later, the insert 36 serving as the compressed air introduction port at the time of demolding is not clogged, and a stable demolding operation can be performed.
[0042]
After the concrete casting is completed and the curing period has elapsed, as shown in FIG. 5, the bolts 65 for which the insert 36 has been set on the inner mold 40 are removed. Then, a hose 45 for supplying compressed air to the insert 36 is connected. The hose 45 is connected to a compressed air source 46 so that compressed air of approximately 8 atm can be supplied as needed. In addition, before and after the hose 45 is connected, the outer formwork 2 is removed, and the crane 50 is mounted on the suspension hook 39.
[0043]
The lower part 31 of the handhole 10 from which the hose 45 is connected and the outer formwork 2 is removed is lifted by the crane 50 as shown in FIG. Then, compressed air is supplied from a compressed air source 46 to the introduction hole 35 formed by the insert 36. The compressed air supplied to the introduction hole 35 reaches the pressure-resistant box 51 through the screw hole 60, but since the air does not leak from the pressure-resistant box 51, the pressure inside the introduction hole 35 increases.
[0044]
As shown in FIG. 7, when the pressure in the introduction hole 35 increases, air pressure acts on the wall surface of the pressure-resistant box 51 and the surface of the inner mold 40 exposed inside the insert 36, and the concrete product is removed from the inner mold 40. A certain lower part 31 peels off. It is considered that air also enters a minute gap between the insert 36 and the inner mold frame 40, and when the pressure in this gap increases, the peeling further proceeds. As the peeling progresses, the gap further widens, and the inner mold 40 and the concrete lower portion 31 are separated smoothly. In the insert 36 of this example, the diameter of the side 36a that comes into contact with the formwork is increased in order to secure an area where the air pressure works at the beginning. Furthermore, since the area of contact with the form around the end 36a is increased by increasing the diameter, a gap is easily formed between the form and the form.
[0045]
Furthermore, in this example, when air is introduced into the interface between the inner mold 40 and the concrete lower portion 31, the inner mold 40 is suspended below the concrete product. For this reason, the own amount of the inner mold 40 also acts in the direction in which the mold 40 is peeled from the concrete lower part 31 in the initial stage of the mold release. Therefore, a gap is easily spread between the mold and the concrete product, and air pressure acts on the widened gap, so that a smooth demolding operation can be performed. In addition, since the inner mold 40 gradually descends while contacting the inside of the concrete lower part 31 by its own weight, the descending speed is very slow, and it does not drop suddenly and is safe. Also, when the descent starts, there is no impact or the like, and the crane does not vibrate. Therefore, in this example, the hose 45 is connected to the introduction hole 35 in advance, but the hose 45 can be fixed to the introduction hole 35 by an operator manually. However, if the hose 45 can be fixed in advance, the worker can perform the demolding work only by controlling the crane and the supply of air, so that only one worker can be used, and labor saving and efficiency can be achieved.
[0046]
Furthermore, since the concrete lower part 31 from which the inner formwork has been removed can be carried out to a predetermined place while being suspended by a crane, it is possible to carry out the work from demolding in a series of operations. Therefore, work efficiency is very good.
[0047]
Further, if the demolding operation is performed by such a method, it is not necessary to forcibly apply an impact to the form by a hammer or the like. Of course, since the inner mold 40 is also merely pushed down by the supplied air like a piston, no extra stress is generated in the mold itself or the concrete product. Therefore, even if the manufacturing method of this example is adopted, there is no need to provide reinforcement or the like to the durable formwork or concrete product, and there is an advantage that the life of the durable formwork can be extended more than before. Further, since it is not necessary to swing a hammer or the like, the labor of the worker is greatly reduced, and the working efficiency can be improved.
[0048]
In this way, in this example, since air is introduced from the concrete product side to the interface with the formwork, a path for introducing air upwards to the formwork, particularly the inner formwork that is problematic during demolding. Can be set. Therefore, the ladle generated during the production of the concrete product rarely flows into the fluid path, and the launder does not block the path. Furthermore, since the insert buried in the concrete product is renewed each time, slack is not accumulated, the compressed air can be supplied stably, and the demolding operation can be performed reliably. For this reason, the degree of taper of the mold may be reduced, and a concrete product having good volumetric efficiency can be efficiently and stably manufactured. In this way, the path for supplying the compressed fluid is constantly updated, so that it is not necessary to clean the path.
[0049]
Of course, in the manufacturing method of this example, there is no need to perform a conventional operation of reversing a concrete product in which the inner mold is disassembled and removed, so that the load on the worker can be reduced and at the same time it is safe. In addition, the trouble of disassembling and assembling the inner mold can be omitted, and a highly accurate mold can be used. Further, since there is no need to provide a mechanism such as a switchgear required for introducing air from the inner mold, the mold is simple and there is no risk of failure.
[0050]
As described above, this introduction hole is used as a drain discharge hole. FIG. 8 shows the vicinity of the introduction hole 35 shown in FIG. 7 in an enlarged manner. The introduction hole 35 of this example is formed by an insert 36 using a small-diameter PVC pipe. The insert 36 has a socket shape with one end portion being wide. The wide end is provided inside the bottom surface 33, that is, facing the recess 34, and a female screw 36 a is formed on the inner surface of the end so that the water stop screw 37 can be screwed. On the other hand, a protrusion 36b is formed at an end of the bottom surface 33 facing the back surface 38. The projection 36b is engaged with a projection 47 provided at the end of a hose 45 for supplying compressed air, so that the hose 45 can be fixed to the air introduction hole 35. Therefore, the introduction hole 35 can be used as a drain hole as it is, and when not used as a drain hole, a water stop bolt 37 may be provided. On the other hand, when the compressed air is introduced in the manufacturing process, the hose 45 can be fixed by using the protrusion 36b, so that the operator for removing the formwork can concentrate on the operation of the crane. Therefore, even one worker can perform the work of removing the formwork.
[0051]
FIG. 9 shows examples of different inserts. The insert 70 has a substantially cylindrical shape made of plastic with an upper end 71 and a lower end 72 open, and a female screw 73 is cut inside the upper end 71. Further, the lower end 72 is widened toward the outer peripheral side, and a flange surface 74 that is in contact with the surface of the mold is formed at the end. A flange 75 is formed on the outer peripheral surface of the insert 70 at substantially the center thereof so as to surround the outer peripheral surface. In addition, three projections 76 projecting toward the center are formed on the inner surface of the insert 70. These projections 76 are formed at substantially equal intervals along the inner circumference.
[0052]
FIG. 10 shows a state where a concrete product is manufactured by setting the insert 70 to the formwork 40. A bolt 77 having a cylindrical tip 78 is inserted into the screw hole 60 of the mold 40. When the insert 70 is inserted into the tip 78, the elastic projection 76 made of plastic presses the tip 78 of the bolt 77, and the insert 70 can be fixed to the formwork 40. Since the protrusion 76 only partially protrudes from the inner surface of the insert 70, a gap 79 that can guide compressed air can be secured between the inner surface of the insert 70 and the tip 78 of the bolt 77. By inserting the lower end 72 of the insert 70 toward the surface of the formwork 40 and bringing the flange surface 74 into contact with the surface of the formwork 40, it is possible to prevent concrete from entering the inside of the insert 70.
[0053]
A series of steps for demolding is the same as that described with reference to FIGS. 5 to 7. First, the distal end of the hose 45 for supplying compressed air is connected using the female screw 71 prepared for the insert 70. When compressed air is introduced from the hose 45, the compressed air passes through the gap 79 and presses the surface of the mold 40. Then, air enters the boundary surface between the concrete surface 33 and the formwork through a gap between the flange surface 74 and the formwork 40, and a smooth demolding operation can be performed. As described above, if the formwork 40 is hung together with the concrete 33, a clearance is easily formed between the flange surface 74 and the formwork 40, so that the mold can be easily removed.
[0054]
In addition, the insert 70 of this example has a function of preventing the concrete wall 33 from coming off and stopping water by a flange 75 provided on the outer peripheral surface. When the wall thickness of the concrete wall 33 is equal to or shorter than the length of the insert 70, the insert 70 may jump out of the concrete wall 33. However, if the flange 75 is provided and buried as in the insert of this example, when the concrete wall 33 is lowered to the ground, even if the portion of the insert 70 that has protruded from the concrete wall 33 is pressed to the ground, the insert 70 is not pressed. There is no problem of coming off the concrete wall. In order to prevent detachment, the shape is not limited to the above-mentioned flange-shaped protrusion, but may be a shape that can enhance the adhesive force when buried in a concrete wall, for example, a columnar protrusion.
[0055]
Further, after removing the hose 45 for introducing air, the female screw 71 prepared in the insert 70 may be closed by attaching the water stop bolt 37 according to the buried condition as described above.
[0056]
FIG. 11 shows an example in which the bolt side for fixing the insert protrudes in the opposite manner to FIGS. 9 and 10. The insert 80 of the present embodiment has a female screw 83 formed at the upper end 81 and a widened flange surface 84 formed at the lower end 82, similarly to the insert described above. A bolt 87 for fixing the insert 80 to the screw hole 60 of the mold 40 is set. The bolt 87 of this example has three projections 86 extending outward at the tip end 88, so that the inner surface of the insert 80 can be pressed and fixed. Therefore, even if the insert and the bolt of this example are used, the gap 89 through which compressed air can be introduced can be secured in the same manner as described above.
[0057]
12 and 13 show different examples of inserts suitable for supplying compressed air from the concrete product side. The insert 90 of the present embodiment is a combination of a base insert 91 and an insert 92 that extends the length of the base insert 91. The same function can be exerted even when only the base insert 91 is used or when one or two or more extension inserts 92 are combined. Therefore, as shown in FIG. 13, when the concrete wall 33 is thin, only the base insert 91 needs to be buried, and when the concrete wall 33 becomes thick, one or two or more extension inserts are provided according to the thickness. 92 can be buried in combination. For this reason, it is possible to cope with concrete products having various wall thicknesses simply by preparing in advance two types of inserts, a base insert 91 and a plurality of inserts 92 for extension, at a site or a factory where concrete products are manufactured. .
[0058]
The insert 90 is an insert that can be used in the same manner as the method described with reference to FIGS. 3 to 8, and a description of a method of installing the mold on a mold and a method of removing the mold using compressed air will be omitted. Both the base inserts 91 and 92 are entirely cylindrical, and are molded products of plastic such as ABS. The end 93 of the base insert 91 that comes into contact with the formwork 40 is open in a flange shape, so that an area where compressed air initially hits the formwork 40 is secured, and at the same time, a gap is formed between the formwork 40 and the concrete wall 33. It is made easy to guide the air to the generated gap. A cylindrical portion 95 having a slightly larger diameter is formed from the flange-shaped end 93 to the opposite end 94, and a female screw 96 is formed on the inner surface thereof. Therefore, after being removed from the mold 40, the water stop bolt 37 formed of plastic or the like is screwed in at the site or the like in the same manner as the insert to close the insert 90.
[0059]
A flange-shaped portion 97 is formed on the outer peripheral surface of the cylindrical portion 95 to fix the insert 90 to the concrete wall 33 and to prevent water from flowing along the outer wall of the insert 90 at the same time. ing. A cylindrical portion 98 having a slightly smaller diameter extends from the cylindrical portion 95 toward the distal end 94, and the distal end 94 can insert and fix the distal end 47 of the hose 45 that supplies compressed air. Two projections 47a project from the end 47 of the hose in the 180-degree direction at the tip 47 of the hose, and engage with the projection 94a prepared inside the tip 94 of the insert. That is, the tip 47 of the hose is inserted into the tip 94 of the insert at an angle such that the projections 47a and 94a do not collide with each other. Are not detached from the insert 90.
[0060]
Further, on the outer periphery of the tip end 94 of the insert, two convex portions 99 indicating an angle at which the hose 45 can be inserted are formed in the direction of 180 degrees. Since the protrusion 99 is visible from the concrete wall 33 even when the insert 90 is embedded, the worker inserts the hose 45 by inserting the protrusion 47 a at the tip of the hose into the protrusion 99. Can be inserted and joined. In this way, if the insert 90 of this example is buried, efficient work can be performed without the labor of connecting while checking the shape of the tip of the hose one by one.
[0061]
The extension insert 92 has a coupling end 100 that can be connected to the tip 94 of the base insert 91 and a tip 101 having the same configuration as the tip 94 of the base insert. Therefore, even if one or a plurality of extension inserts 92 are combined with the base insert 91, the hose 45 can be easily connected and detached similarly to the above. The coupling end 100 has a cylindrical shape whose inside diameter is such that it can be inserted while being in contact with the outer peripheral surface of the distal end 94 of the base insert 91. The 180 ° direction of the cylindrical side surface is extended outward to form the base insert 91. A portion 103 into which the two convex portions 99 extending outward from the tip 94 of the target portion 94 can be fitted is formed. Since the tip 101 of the extension insert 92 has the same shape as the tip 94 of the base insert 91, another extension insert 92 can be further stacked on the extension insert 92 to assemble inserts of various lengths.
[0062]
As described above, the insert 90 of the present embodiment can form an introduction hole penetrating through concrete walls having various wall thicknesses with a small number of inserts, so that an air path is provided on the concrete product side as disclosed in the present embodiment. This is an insert suitable for a manufacturing method used for a mold release operation. Furthermore, the insert of this example has a function indicating the angle at which the hose can be attached and detached so that the hose can be easily connected, and has many functions as described above, so that the work at the time of demolding is further facilitated. Become.
[0063]
In the above example, the lower part of the handhole having a closed bottom is described as an example. be able to. Also, the path of the compressed air is not limited to the bottom surface, but may be provided on the side surface, and the number of paths is not limited to one. Furthermore, the concrete molded product is not limited to a square handhole, and may be cylindrical. In addition, it goes without saying that the above manufacturing method can be similarly applied to other concrete molded products such as a water collecting basin and a U-shaped groove. Further, the method is not limited to removing the inner mold, and if an insert or the like is installed in a similar manner, compressed air can be used to remove the outer mold.
[0064]
Further, instead of the compressed air, another gas such as nitrogen or a fluid can be used. The insert forming the passage is not limited to the insert made of PVC or other plastics, but may be a metal insert. Furthermore, it is also possible to configure a path for introducing air into the concrete using a paper sleeve or the like.
[0065]
By using the concrete product described above and the method of manufacturing the same, the demolding operation can be performed safely, reliably, and easily using compressed air or the like in a factory or the like. Therefore, the labor of the worker can be greatly reduced, the damage of the mold can be prevented, and the life of the mold can be extended. Further, since the mold can be reliably and smoothly removed from the mold, it is possible to use a mold having a small degree of taper, thereby providing a concrete product with high volume efficiency. In addition, since the production efficiency is good and the production period can be shortened, a high-quality concrete product can be provided at low cost.
[0066]
The structure of the mold itself may be simple, and there is no need to operate a complicated mechanism to remove the mold, so that work is not interrupted due to a failure or the like. Also in this respect, the efficiency of the work can be improved, and there is no extra burden on the worker for repair and the like.
[0067]
【The invention's effect】
In the present invention, a concrete basin is formed by using an inner form having a tapered side surface, and the inner form is removed by lifting the concrete basin using a suspension hook attached to the bottom of the concrete basin. Therefore, it is not necessary to invert the concrete basin, and it is possible to save the labor of disassembling and assembling the inner mold.
[0068]
In addition, the hanging hook buried in the back of the bottom surface of the concrete product can be used for removing the formwork, can also be used for transporting the concrete product, and can be easily cut when it becomes unnecessary .
[Brief description of the drawings]
FIG. 1 is a perspective view partially showing an outline of a handhole according to an embodiment of the present invention.
FIG. 2 is a cross-sectional view showing a structure of the handhole shown in FIG.
FIG. 3 is a cross-sectional view showing a manner of assembling a mold in a process of manufacturing a lower portion of the handhole shown in FIG.
FIG. 4 is a cross-sectional view showing a state in which concrete is poured into a formwork in a process of manufacturing the lower portion of the handhole shown in FIG.
FIG. 5 is a cross-sectional view showing a state in which a compressed air source is connected in a step of manufacturing the lower portion of the handhole shown in FIG.
FIG. 6 is a cross-sectional view showing a state in which the lower portion is suspended in a process of manufacturing the lower portion of the handhole shown in FIG.
FIG. 7 is a cross-sectional view showing a state in which the inner mold is removed using compressed air in a step of manufacturing the lower portion of the handhole shown in FIG.
FIG. 8 is an enlarged view showing details of an introduction hole installed at a lower portion of the hand hole shown in FIG. 1;
FIG. 9 is a sectional view (a) and a plan view (b) showing an embodiment of a different insert according to the present invention.
FIG. 10 is a cross-sectional view showing a state where a concrete wall has been manufactured using the insert shown in FIG. 9;
FIGS. 11 (a) and 11 (b) are a cross-sectional view and a plan view showing examples of different inserts and formwork according to the present invention. FIGS.
FIG. 12 is an exploded perspective view showing an outline of still another insert according to the present invention.
FIG. 13 is a sectional view showing the structure of the insert shown in FIG.
FIG. 14 is a cross-sectional view showing a state in which a concrete basin is manufactured by using a conventional inner mold that is assembled and used.
FIG. 15 is a cross-sectional view showing a state where a concrete basin is manufactured using the tapered inner formwork according to the present invention.
[Explanation of symbols]
1 ・ Baseboard
2. Outer formwork
3 ・ ・ Inner formwork
8. Factory concrete
10. Concrete basin
20. Handhole
21. The upper part of the handhole
22, 32, side
23 ... top
25, 35..Introduction hole
26, 36 Inserts using PVC pipes
31. The lower part of the handhole
33 ... bottom
34 ... dent
37 ... water stop bolt
40 ... Inner formwork
45. Hose for compressed air
46 ・ ・ Compressed air source
50 crane
60. Screw holes for setting inserts
61 ・ ・ Box with pressure resistance
70,80 ・ ・ Insert
71, 81-The upper end of the insert
72, 82 · · · the lower end of the insert
73, 83 female screw
74, 84 · · · flange surface
75, 85 ... Tsuba
76 ··· Projection protruding from inner surface of insert
77, 87..Bolts for fixing inserts
86 Projection protruding from the outer surface of the bolt
79, 89 ··· Gap that can lead compressed air
91 inserts
92 ・ ・ Insert for extension
99 ・ ・ Protrusion indicating the mounting / detaching angle of the hose

Claims (7)

A method for producing a masu-shaped concrete product using a durable formwork,
An inner mold that defines the inner surface of the concrete product has a tapered side surface, and the concrete product has an introduction hole for introducing air to an interface with the inner mold. A method for manufacturing a concrete product, comprising lifting the product and removing the inner formwork. 2. The method for manufacturing a concrete product according to claim 1, wherein a hook for hanging is buried on a back surface of a bottom surface of the concrete product, and the concrete product is lifted using the hook for hanging. 2. The method for manufacturing a concrete product according to claim 1, wherein an impact is applied when the inner mold is removed. A square-shaped concrete products produced using the durability of the mold, the inner side surface Gath - Pas shape der is, the interface between the inner mold defining the inner surface when manufacturing the concrete product concrete product characterized that you have introduction hole for introducing air is provided. 5. The concrete product according to claim 4, wherein a hanging hook is buried on the back surface of the bottom surface, or the hanging hook buried on the back surface of the bottom surface is cut . 5. The concrete product according to claim 4, wherein a cylindrical insert forming the introduction hole is buried. 7. The concrete product according to claim 6, wherein the insert can be attached to at least one end with a means for closing the insert.

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