JP2017222105A - Mold frame cooling device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make frame removal of a box shaped concrete molded article easier by efficiently cooling and shrinking only an inner mold frame without breaking a concrete molded article surface contacting a mold frame.SOLUTION: During frame removal of a concrete molded article K by a ready mixed concrete installed into an internal space S formed between an inner mold 2 and an outer mold 3 of a frame mold 1, a nozzle 10 for mist water spraying for spraying water with a mist shape to an inner face of the inner mold 2 and cooling and shrinking the inner mold 2 by vaporization heat is equipped. The nozzle 10 for mist water spraying has a concrete molded article K under a mold removal treatment line L transferred together with a mold frame 1. The concrete molded article has a box shaped hole structure embedded underground of a hand hole or a manhole for example, can be one of an upper stage block with circular opening for going in and out to an upper wall center, a cylindrical middle stage block of which upper and lower are opened and a square shaped lower stage block.SELECTED DRAWING: Figure 2

Description

  The present invention, for example, demolding a concrete molded product molded into a box-shaped hole structure embedded in the ground such as a hand hole or a manhole after being transported from a steam curing room from a concrete molding form In particular, the present invention relates to a mold cooling apparatus that suppresses thermal expansion of a mold inside thereof and cools and contracts with heat of vaporization in which cooling water is sprayed in a mist form.

  For example, a hand hole or the like, which is a box-shaped hole structure embedded in the ground or the like, is made into a product by injecting ready-mixed concrete into the inner and outer molds at a manufacturing plant and demolding after curing. The hand hole is configured in the shape of a hexahedron having, for example, an upper wall having an upper opening with an iron top lid, one bottom wall, and four side walls. In general, it is manufactured by dividing into lower blocks and is buried in the ground as a hand hole by overlapping and connecting vertically. In some cases, for example, an upper block having a circular opening through which a person enters and exits the hand hole at the center of the upper wall, a cylindrical middle block, and a bowl-shaped lower block are manufactured.

  The inner and outer molds filled with ready-mixed concrete are placed in a sealed steam-curing room and filled with steam at about 60 ° C for approximately half a day to heat the entire room to a high temperature, and the reaction of the ready-mixed concrete becomes solid. The so-called steam curing treatment is promoted to rapidly increase the strength. After this curing, the inner and outer molds coming out of the steam curing room and the concrete in the inner and outer molds are thermally expanded, and a phenomenon that the concrete molded product is difficult to come off from the inner and outer molds occurs. However, in order to make it easy to come off, if the water is sprinkled with cold water after demolding or water is discharged at the time of joint processing (latency treatment) after placing concrete, surface cracks may occur by rapidly cooling the surface of the concrete molded product. .

  Therefore, various devices have been devised as a mold cooling device for facilitating removal of the concrete molded product from the inner and outer molds at the time of demolding after curing the concrete molded product. For example, in the method for forming a large-sized concrete secondary product with a bolt pocket disclosed in Patent Document 1, a bolt pocket that has been heated by opening the mold side plate and the mold end plate after curing the concrete molded product with ready-mixed concrete. After the forming mold and its periphery are rapidly cooled and contracted, the concrete segments with bolt pockets are removed from the bolt pocket forming mold and the mold bottom plate. That is, the mold is removed by a slight difference between the coefficient of thermal expansion and the difference in specific heat between the concrete molded product and the steel mold, and a slight gap between the concrete molded product and the mold.

  Moreover, in the manufacturing method of the concrete product which has the hollow part currently disclosed by patent document 2, the resin pipe is cooled by naturally cooling the concrete temperature to near normal temperature, or the resin pipe is forcibly cooled by water cooling or air cooling. As a result, a gap is formed between the resin pipe whose diameter has been reduced due to the temperature drop and the inner surface of the hollow part formed into a predetermined shape, and then the resin pipe end is grasped and removed from the hollow part. The pipe is used again as a core member.

  Moreover, in the concrete curing method disclosed in Patent Document 3, a ventilation space for circulating cooling air for cooling the cast concrete is formed in the concrete casting mold, and the flow path of this cooling air In addition, an air cooling mechanism using heat of vaporization and evaporation of water is provided, and air cooled by the air cooling mechanism is circulated in the ventilation space.

Japanese Patent No. 2750076 Japanese Patent No. 4148683 JP 2014-221979 A

  However, in the case of the mold cooling device according to Patent Document 1 and Patent Document 2 described above, the mold such as the bolt pocket forming mold or the resin pipe core member is forcibly rapidly cooled at the time of demolding. At the same time, the surface of the concrete molded product in contact with the mold is also rapidly cooled, which may cause cracks on the surface. Incidentally, sprinkling with cold water after demolding and water discharge at the time of jointing treatment (latency treatment) after placing concrete causes surface cracks by rapidly cooling the surface of the concrete molded product.

  Further, in the case of the mold cooling apparatus according to Patent Document 3, the air cooled by the air cooling mechanism using the heat of vaporization of water is circulated through the ventilation space of the mold to cool the concrete molded product while ensuring a sufficient heat capacity. Because it is cured and hardened, the heat of the formwork cannot be taken away and the concrete molded product does not come out very well.

  For example, when molding a concrete hand hole, a raw concrete material is placed in the internal space between the inner and outer molds, and after forming, the inner and outer molds are removed to form a box-shaped concrete molded product. When taking out, the outer mold itself can be disassembled and separable, for example, can be laid down or removed. However, removing the inner mold by disassembling the inside of the concrete molded product becomes complicated in order to reverse the concrete molded product once or to separate and reassemble the inner mold. It is extremely troublesome. In addition, it is possible to remove the inner mold form itself by spray application of a release agent for easy peeling or because the inner mold form is in a thermal expansion state due to steam curing and is in close contact with the concrete molded product. Making it difficult.

  Therefore, the present invention was created in view of the existing circumstances as described above, and its purpose is to form a concrete such as a hand hole by raw concrete placed in an inner / outer formwork arranged inside and outside. After molding the product, when the concrete molded product is extracted from the inner and outer molds, the surface in contact with the inner and outer molds after the molding is not damaged, and the thermal expansion of only the inner molds is efficiently suppressed. To provide a mold cooling device that can be easily demolded by efficiently shrinking the inner mold from the inner surface of the concrete molded product by cooling and shrinking with cooling water sprayed in a spray form. It is in.

In order to solve the above-described problems, in the present invention, a concrete molded product formed by ready-mixed concrete placed in the internal space S formed between the inner mold 2 and the outer mold 3 of the mold 1. At the time of demolding of K, a mist water injection nozzle 10 is provided for spraying water in the form of a mist toward the inner surface of the inner mold 2 to cool and contract the inner mold 2 with heat of vaporization.
The fog water jet nozzle 10 may be provided below the demolding processing line L for transporting the concrete molded product K together with the mold 1.
The above-mentioned concrete molded product K is an upper block having a circular opening 9 for people to enter and exit in the center of the upper wall constituting a box-shaped hole structure embedded in the ground of a handhole / manhole, and the top and bottom are open It can be either a cylindrical middle block or a bowl-shaped lower block.

  In the formwork cooling apparatus according to the present invention configured as described above, the fog water jet nozzle 10 is jetted toward the inner surface of the inner mold 2 to cool the inner mold 2 with heat of vaporization, The thermal expansion of the inner mold 2 itself is suppressed, and a gap δ is formed between the inner mold 2 and the concrete molded product K due to shrinkage toward the inside, and the inner mold 2 is separated. Thus, the frictional resistance between the inner mold 2 and the concrete molded product K is reduced, and the concrete molded product K is removed from the inner mold 2 by lifting the concrete molded product K upward, for example.

  Since the present invention is configured as described above, the surface that is in contact with the mold 1 when the concrete molded product K such as a handhole is cast from the mold 1 by the cast concrete that has been placed. The inner mold 2 can be efficiently peeled from the inner surface of the concrete molded product K by cooling and shrinking only the inner mold 2 without damaging the mold and efficiently suppressing thermal expansion. For example, the mold can be easily removed by lifting only the molded product K upward, for example.

  In other words, this is because when the present invention demolds the concrete molded product K formed by the ready-mixed concrete cast in the internal space S formed between the inner mold 2 and the outer mold 3 of the mold 1. This is because the mist water spray nozzle 10 for spraying water in the form of a mist toward the inner surface of the mold 2 and cooling and shrinking the inner mold 2 with heat of vaporization is provided. Thereby, for example, for the inner mold 2 which is in a relatively high temperature state due to curing in the steam curing chamber, the thermal expansion is suppressed, and the principle of heat of vaporization by the cooling water sprayed in the form of mist is reduced. It can be cooled by taking it away. In this cooling, the inner mold 2 is shrunk inward to form a gap δ between the concrete molded product K and the inner mold 2 and peeled off from the inner surface of the concrete molded product K. By reducing the frictional resistance with the product K, the concrete molded product K can be easily pulled out.

  Moreover, since the fog water injection nozzle 10 is provided below the demolding processing line L for transporting the concrete molded product K together with the mold 1, the inside of the concrete molded product K during the continuous transport, The heat of only the inner mold 2 disposed below can be efficiently taken away, and the subsequent demolding of the concrete molded product K can be performed smoothly.

  In addition, the concrete molded product K is composed of an upper block having a circular opening 9 through which a person enters and exits in the center of an upper wall constituting a box-shaped hole structure embedded in a handhole / manhole, Each of the blocks for constructing a hand hole by each of the blocks according to the heat of vaporization by the fine mist from the mist water injection nozzle 10 is used. Facilitates the demolding of the type of concrete molding K.

  In addition, the code | symbol attached | subjected in each means of the means for solving said subject and the effect of invention was attached | subjected in order to make easy reference with the part which shows each structure part described in drawing. The present invention is not limited to these descriptions, structures, shapes, and the like indicated by reference numerals and the like in the drawings.

It is a perspective view for demonstrating roughly the heat of vaporization principle by use of the nozzle for mist water injection in one form for carrying out the present invention. An example of the demolding process on the demolding processing line of a concrete molded product is shown. (A) lays down the outer mold after curing the ready-mixed concrete, and sprays water toward the inner surface of the inner mold with a nozzle for spraying misty water (B) is a side view of a state in which the inner mold is cooled and contracted by heat of vaporization and a gap is formed between the concrete molded product and the inner mold, and (c) is a concrete molded product. It is a side view of the state which lifts and is extracted from the inner mold.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, an embodiment for carrying out the present invention will be described with reference to the drawings. Reference numeral 1 shown in the drawings denotes a concrete which is a box-shaped hole structure embedded in the ground such as a handhole or a manhole. It is a formwork arranged inside and outside for producing the molded product K.

  The mold frame 1 has a rectangular frame-shaped bottom wall 6 in which the upper opening side of the rectangular tube side wall 4 is closed by the top wall 5 and extends outward from the lower opening side edge of the rectangular tube side wall 4. The inner die 2 is formed as a single box with a downward opening structure, and the outer die 3 is mounted at the outer edge of each side of the bottom wall 6 so that it can be raised and lowered by, for example, a hinge portion 7.

  In the standing state of the outer mold 3, the inner mold 2 is enclosed in a rectangular tube shape, and each corner portion of the outer mold 3 is fastened and fixed by a hook lever or the like (not shown) so that both the inner and outer molds 2, 3 In the meantime, a square cylinder-shaped internal space S for forming a concrete molded product K to be a hand hole member, such as a box shape or a cylinder shape, is formed by placing ready-mixed concrete and forming it.

  At the center of the top surface wall 5 of the inner mold 2, for example, a circular drum-shaped protruding portion 8 protrudes upward, and the upper portion of the protruding portion 8 is closed. Further, in the standing state of the outer mold 3, the upper tip portion of the outer mold 3 is set to be slightly lower than the upper surface of the protruding portion 8.

  When placing the ready-mixed concrete in the internal space S, it is assumed that the upper end portion of the outer mold 3 located slightly lower than the upper surface of the projecting portion 8 is filled. In the center of the upper wall, a circular opening 9 for entering and exiting a person is formed. Of course, in the case of a tubular shape, or in the case of a box shape without an entrance / exit, this protrusion 8 is not provided.

  Also, after ready-mixed concrete is placed in the internal space S of the mold 1 assembled by the inner mold 2 and the outer mold 3, it is left, for example, overnight in a high-temperature steam atmosphere in a steam curing chamber (not shown). By promoting the chemical reaction in the ready-mixed concrete, the strength is increased. Then, it is carried out from the steam curing room, the mold 1 is removed from the mold, and the concrete molded product K is taken out.

  When the concrete molded product K is taken out, in order to demold the concrete molded product K formed by the cast concrete that has been placed, the concrete molded product K is, for example, in the form of a square frame with the inside open. It is placed on the pedestal P and conveyed by the conveying roller R to the position of the misty water jet nozzle 10 disposed below the demolding processing line L. In the middle of the conveyance, the outer die 3 is put in a lying state by the hinge portion 7 and separated from the outer side surface of the concrete molded product K. For example, the outer die 3 is opened to the outer oblique state by the hinge portion 7.

  If necessary, the outer mold 3 is not raised and lowered by the hinge portion 7, but the hook lever is removed while the outer mold 3 is standing upright, and the outer mold 3 is disassembled from the inner mold 2. The outer mold 3 may be detached from the inner mold 2 and disassembled.

  The fog water jet nozzle 10 is, for example, for spraying water in the form of a mist toward the inner surface of the inner mold 2 in a state where the outer mold 3 is laid down, and cooling and shrinking the inner mold 2 with heat of vaporization. is there. The mist water injection nozzle 10 is composed of, for example, a plurality of parts (not shown) such as a nozzle tip, a waller, an adapter, an air pipe, and a liquid pipe, and compressed air and liquid are contained inside the mist water injection nozzle 10. There is an internal mixing type that atomizes by mixing. In this case, the liquid flows in the center of the nozzle and the compressed air flows in the outer periphery thereof. There is also a two-fluid-conical nozzle type that pressurizes and supplies two liquids to generate a large amount of fine mist. In addition, there is also a three-fluid empty conical nozzle that can be sprayed by mixing two types of liquid and compressed air, which can be atomized by mixing the first liquid with the compressed air and mixing the second liquid externally. Is going. The atomization of the cooling water by the mist water injection nozzle 10 in a mist state is selected as the optimum by appropriately setting the nozzle structure and shape.

  Specifically, the mist water injection nozzle 10 has an average particle diameter of 50 μm and a maximum particle diameter of 150 μm, for example, when the air / water ratio is 130, and has a wide flow rate adjustment range of low air / water ratio design. The spray flow rate is, for example, a compressed air pressure of 0.3 MPa, the liquid pressure is 0.2 to 0.5 MPa, the air consumption is, for example, a compressed air pressure of 0.3 to 0.4 MPa, and the foreign matter passage diameter is a 60 ° type liquid. Is mentioned as an example, but is not limited thereto.

  That is, in the case where mere water is applied, the heat of the inner mold 2 cannot be taken away so much and the escape of the concrete molded product K from the inner mold 2 is not so good. The inner mold 2 is cooled and contracted by utilizing the heat of vaporization that takes away the heat of only the inner mold 2 by evaporating when touching. Here, the heat of vaporization is the amount of heat absorbed from the outside when the liquid is vaporized, and the absorbed heat is not used for temperature rise but is used as energy for vaporization. The amount of heat required to convert 1 gram of liquid into a gas at the same temperature is, for example, equal to 539.8 calories for water at 100 degrees Celsius.

  Next, the production, curing, and demolding steps of the concrete molded product K using the cast concrete will be described. First, a formwork comprising a box-shaped inner mold 2 and an undulating outer mold 3 for concrete molding. A mold release agent (not shown) is spray-applied to 1 in advance, and the inner mold 2 is surrounded with the outer mold 3 in an upright state, thereby forming a rectangular cylindrical inner space S between the inner and outer molds 2 and 3. Keep it. The ready-mixed concrete is placed in the internal space S between the inner and outer molds 2 and 3 and then steam-cured at a predetermined temperature for a predetermined time in the steam-curing chamber to obtain a concrete molded product K. In order to demold the concrete molded product K, it is placed on a carriage / pedestal P and conveyed by the conveying roller R to the position of the misting water jet nozzle 10 disposed below the demolding processing line L.

  Next, the process proceeds to a demolding step for the concrete molded product K on the demolding line L. That is, after the hook lever is removed and the outer mold 3 is opened in a lying state by the hinge portion 7, fine mist is sprayed by the fog water spray nozzle 10 and sprayed uniformly over the entire inner surface of the inner mold 2. As a result, mist-like water is brought into contact with the inner surface of the hot inner mold 2 and cools by taking the heat of the inner mold 2 on the principle of heat of vaporization (see FIGS. 1 and 2A). Then, when the inner mold 2 is cooled, the inner mold 2 contracts substantially uniformly toward the inside, and a gap δ is formed between the inner mold 2 and the concrete molded product K. The frictional resistance with the concrete molded product K is reduced (see FIG. 2B).

  Next, the concrete molded product K is removed from the inner mold 2. For example, the concrete molded product K is lifted with a heavy machine such as a crane (not shown) and lifted to be extracted from the inner mold 2 and concrete, for example, a box-shaped hole structure embedded in the ground such as a handhole or a manhole. It becomes a product (see FIG. 2C).

  In addition, as a concrete molded product K used as a hand hole, an upper block having a circular opening 9 for a person to enter and exit the hand hole at the center of the upper wall, a cylindrical middle block having an open top and bottom, a bowl shape Even in the case of being manufactured by dividing into three types of lower blocks, after the inner mold 2 is cooled and contracted, the outer mold 3 is opened or removed in the lying state, or the outer mold 3 is opened or removed in the lying state. After the inner mold 2 is cooled and contracted, the concrete molded product K is lifted by a crane and extracted.

  Depending on the product, for example, in the case of a multi-stage type, the bottom part of the bottom part or the middle part of the cylindrical part is open up and down. The inner mold 2 is separated from the concrete molded product K by being cooled and contracted by heat of vaporization, and the concrete molded product K can be taken out.

K ... Concrete molded product S ... Inner space R ... Conveying roller P ... Base L ... Demolding line δ ... Gap 1 ... Formwork 2 ... Inner mold 3 ... Outer mold 4 ... Square tube side wall 5 ... Top wall 6 ... Bottom wall 7 ... Hinge part 8 ... Projection part 9 ... Opening part 10 ... Nozzle for mist water injection

Claims (3)

  When demolding a concrete molded product molded from ready-mixed concrete placed in the internal space formed between the inner mold and the outer mold of the mold, water is sprayed in a mist toward the inner surface of the inner mold. A mold cooling apparatus comprising a fog water jet nozzle for cooling and shrinking the inner mold with heat of vaporization.   2. The mold cooling apparatus according to claim 1, wherein the mist water injection nozzle is provided on a lower side of a demolding processing line for conveying a concrete molded product made of ready-mixed concrete together with the mold.   The concrete molded product is an upper block having a circular opening for a person to enter and exit in the center of the upper wall constituting a box-shaped hole structure embedded in the ground of a handhole / manhole, and the upper and lower sides are opened. The formwork cooling device according to claim 1 or 2, wherein the formwork cooling device is one of a cylindrical middle block and a bowl-shaped lower block.

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