JP2013244503A - Mold manufacturing device and manufacturing method of mold - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a mold manufacturing device, a manufacturing method of a mold, which can easily change a path so as to be capable of supplying gas to a cavity accurately, even if being in a case etc. to change the shape of the cavity according to the structure of mold, and can manufacture an even mold.SOLUTION: A mold manufacturing device includes a forming die having a cavity in which coated sand can be charged, and a gas supply means which supplies gas to the cavity, wherein the forming die is communicated with the cavity, and has an upper surface communication path opening in an upper surface, a lower surface, a first side surface, and a second side surface, a lower surface communication path, a first side surface communication path, and a second side surface communication path, and wherein at least any two kinds of the communication path among these upper surface communication path, lower surface communication path, first side surface communication path, and second side surface communication path are connected to the gas supply means with their communication state being changeable, at least one kind of the communication path has a function to discharge the gas of the cavity.

Description

  The present invention relates to a mold manufacturing apparatus and a mold manufacturing method.

  Currently, a mold manufacturing apparatus is provided in accordance with a mold manufacturing method such as a self-hardening mold, a shell mold mold, or an investment mold mold. In a mold manufacturing apparatus using a coated sand coated with a fireproof aggregate with a water-soluble binder, a manufacturing apparatus is provided in which the coated sand is heated and solidified and cured by blowing water vapor into the coated sand filled in the mold. Yes.

  As a mold manufacturing apparatus using the coated sand, a mold manufacturing apparatus (International Publication No. 2006/054346) shown in FIG. 10 and a mold manufacturing apparatus (Japanese Patent Laid-Open No. 2011-230180) shown in FIG. 11 are known. .

  A mold manufacturing apparatus shown in FIG. 10 includes a mold 102 having a cavity 101 therein, a water vapor supply means 103 for supplying water vapor to the cavity 101, a plurality of water vapor discharge passages 104 for discharging water vapor from the cavity 101, and a plurality of water vapor discharge passages 104. The flow rate adjusting means 105 is arranged in at least one of the above and adjusts the amount of water vapor discharged from the cavity 101, and the control means 106 controls the flow rate adjusting means 105 so that the cavity 101 is uniformly filled with water vapor. . This mold manufacturing apparatus has a water vapor discharge path 104 that introduces coated sand and water vapor into the cavity 101 from the upper side of FIG. 10 through a single supply path, and is discharged from the left and right side surfaces and the lower three directions. Even when resin coated sand having a low porosity is used, a mold having a complicated shape can be efficiently produced by supplying water vapor in a short time.

  The mold manufacturing apparatus shown in FIG. 11 includes a mold 108 having a cavity 108 filled with a coated sand 107 coated with a refractory aggregate with a binder, an injection path 114 and an exhaust path 115, and an injection path 114 of the mold 109. Is provided with a steam generator 110 for generating steam to be supplied to the cavity 108 from the inside. The mold 109 has a mold heating cavity 111 at a position surrounding the cavity 108. The mold heating cavity 111 is supplied with steam from the steam generator 110 via the steam supply path 112. The molding die 109 has a plurality of water vapor introduction passages 113 that communicate the mold heating hollow passage 111 and the cavity 108 and introduce water vapor supplied to the mold heating hollow passage 111 into the cavity 108. In this mold manufacturing apparatus, the coated sand 107 is filled into the cavity from the injection path 114. In addition, the water vapor is introduced from the injection passage 114 and is introduced from the left and right side surfaces of the water vapor introduction passage 113 through the mold heating cavity passage 111, and the water vapor introduced into the cavity 108 is disposed in the lower exhaust passage. 115 is exhausted.

International Publication No. 2006/054346 JP 2011-230180 A

  However, since the mold manufacturing apparatus of FIG. 10 has a plurality of water vapor discharge passages 104 for discharging water vapor to one water vapor supply means 103 for supplying water vapor, there are many water vapor discharge passages 104 in the mold structure. Thus, there is no problem as long as the mold structure is better evacuated from a plurality of locations. However, in the case of a mold structure, for example, a vertically long mold structure, the effect is not necessarily obtained even if there are many steam discharge passages 104. Rather, it is not preferable to supply water vapor to a mold structure where it is desirable to have more water vapor supply means 103. Further, since one supply flow channel from the upper surface of the mold 102 and one water vapor discharge passage 104 are provided on the lower surface and both side surfaces, for example, when a mold having a structure close to a flat plate is formed, a flat plate In other words, water vapor is discharged from a single point, and it cannot be said that water vapor is supplied and discharged uniformly. As described above, the mold manufacturing apparatus shown in FIG. 10 has a disadvantage in that it may be unoriented depending on the structure of the mold. For this reason, depending on the change of the cavity shape, there is a possibility that unevenness occurs in the manufactured mold.

  Also, in the mold manufacturing apparatus of FIG. 11, water vapor is supplied from the injection path 114 above the mold 109 to the cavity 108 and from the water vapor introduction path 113 to the cavity 108 via the mold heating cavity path 111. Because of the configuration of exhaust from the exhaust passage 115, it takes time to exhaust depending on the structure of the mold, too much water is supplied and the coated sand 107 gets wet more than necessary, and it takes time to dry. Depending on the structure of the mold, there is an inconvenience that the orientation is unsuitable, for example, the desired wetness cannot be obtained and unevenness occurs in curing. In addition, since the mold heating cavity 111 and the water vapor introduction passage 113 are provided in the mold 109, it is difficult to manufacture the mold 109, and it takes time and cost to manufacture the mold. When the mold has a complicated structure or an extremely biased structure, there is an inconvenience that it is very difficult to form the mold heating cavity path 111 and the water vapor introduction path 113. In addition, since the steam flow path is provided in the mold 109, the structure becomes complicated, and when the water vapor introduction path 113 is clogged, the mold 109 must be disassembled and the maintenance management becomes troublesome. Since the flow path is provided in 109, the strength of the mold 109 is lowered, which is inconvenient for long-term use. Further, when the cavity shape is changed, a water vapor channel must be formed in the mold 109 every time for each mold, and the cavity shape cannot be easily changed.

  The present invention has been made in view of these disadvantages, and the object of the present invention is to enable accurate gas supply to the cavity even when the shape of the cavity is changed according to the structure of the mold. An object of the present invention is to provide a mold manufacturing apparatus and a mold manufacturing method capable of easily changing a path and manufacturing a mold without unevenness.

The present invention has been made to solve the above-described problems, and the mold manufacturing apparatus of the present invention includes:
A mold having a cavity capable of being filled with coated sand;
A mold manufacturing apparatus comprising gas supply means for supplying gas to the cavity,
The mold has a top surface, a bottom surface, a first side surface, a second side surface, and a top surface, a bottom surface, a first side surface, and a second side surface, which communicate with the cavity.
At least any two of the upper surface communication path, the lower surface communication path, the first side surface communication path, and the second side surface communication path are connected to the gas supply means so that the communication state can be changed, and at least one type of communication path is provided. The passage has a function of exhausting the gas in the cavity.

  In the mold manufacturing apparatus, the gas supplied from the gas supply means is supplied to the cavity through the communication path in communication with the gas supply means, and the gas in the cavity is exhausted from at least one type of communication path. The Here, the mold manufacturing apparatus is connected to the gas supply means so that at least any two of the upper surface communication path, the lower surface communication path, the first side surface communication path, and the second side surface communication path can change the communication state. Thus, the communication path suitable for the structure of the mold, etc., among the at least any two types of communication paths can be communicated with the gas supply means, and gas can be supplied from the communication path to the cavity. A specific example will be described. For example, when the upper surface communication path and the first side surface communication path are connected to the gas supply means so that the communication state can be changed, the upper surface communication is related to the gas supply to the cavity. Only the passage is in communication with the gas supply means, only the first side communication path is in communication with the gas supply means, or both the upper surface communication path and the first side communication path are in communication with the gas supply means. The gas can be supplied to the cavity from the communication path corresponding to the mold structure or the like. For this reason, it becomes possible to supply a gas that matches the shape of the cavity, and it is possible to manufacture a mold without unevenness. In other words, the mold manufacturing apparatus can be used to change the cavity shape according to the structure of the mold, etc. Gas supply can be performed, and thereby a uniform mold can be produced.

  In the mold manufacturing apparatus, it is preferable that the gas supply means has an on-off valve for changing the communication state with the communication path. Thus, the open / close valve can easily and reliably change the communication path in communication with the gas supply means.

  In the mold manufacturing apparatus, at least one of the communication paths to which the gas supply means is connected can be in communication with the outside air in a non-communication state with the gas supply means, and with the gas supply means. It is preferable to be provided so as to be in a non-communication state with outside air in the communication state. As a result, the one kind of communication path functions as a gas injection path in a communication state with the gas supply means and in a non-communication state with the outside air, and also in a non-communication state with the gas supply means and in a communication state with the outside air. Functions as an exhaust passage. In other words, this communication path can be selectively used as an injection path or an exhaust path, so that there are more options for the gas flow path in the cavity, and a mold without unevenness can be manufactured more reliably.

  In the mold manufacturing apparatus, the first side surface and the second side surface are preferably opposed to each other. Thereby, the supply of gas to the cavity and the exhaust can be more effectively performed using the communication paths of the first side surface and the second side surface that oppose each other.

  In the mold manufacturing apparatus, the upper surface communication path, the first side surface communication path, and the second side surface communication path are connected so that the communication state with the gas supply means can be changed, and the lower surface communication path, the first side surface communication path, and the first side communication path The two side communication passages are provided so that the communication state with the outside air can be changed, and the first side communication passage and the second side communication passage can be in communication with the outside air in a non-communication state with the gas supply means. At the same time, it is preferably provided so as to be in a non-communication state with the outside air in a communication state with the gas supply means. The mold manufacturing apparatus adopting this configuration, for example, by placing the upper surface communication path, the first side surface communication path and the second side surface communication path in communication with the gas supply means, and the lower surface communication path in communication with outside air, Gas can be supplied from above and from the side of the cavity and exhausted from below. In the mold manufacturing apparatus adopting this configuration, for example, the upper surface communication path is in communication with the gas supply means, and the lower surface communication path, the first side surface communication path, and the second side surface communication path are in communication with outside air. Thus, gas can be supplied from above the cavity and exhausted from below and from the side.

  The mold manufacturing apparatus has a recess opening on the abutting surface side and a jacket communication path capable of supplying gas from the gas supply means to the recess, and the recess is the first side surface communication path or the second side communication path. It is preferable to further include a side jacket configured to be attachable to the mold so as to cover one external opening of the side surface communication path. As a result, it is necessary to change the shape of the cavity by changing the shape of the mold, and even when it is desired to form the first side surface communication path and / or the second side surface communication path at a position suitable for the shape of the cavity, A desired location and a desired number of communication paths can be formed within a range in which the opening of the recess can be covered. Accordingly, a communication path that matches the shape of the cavity is provided, and a mold without unevenness can be manufactured.

  A plurality of first series passages or second communication paths are formed on the first side surface or the second side surface of the mold, and the concave portion is formed so as to cover the plurality of first series passages or second communication passages. It is preferable. Thereby, supply of the gas to a cavity can be performed efficiently and in a short time from the side to the whole. In addition, since the isobaric gas is supplied from the concave portion of the jacket to the plurality of communication passages, it is possible to always supply a stable gas at the same pressure.

  It is preferable that the side jacket further has a discharge path capable of discharging the gas in the recess, and the discharge path is provided so as to be openable and closable. Thereby, when the recessed part of a side part jacket is a non-communication state with a gas supply means, the discharge of a gas can be discharged | emitted from a side surface by opening a discharge path.

  It is preferable to further include suction means for sucking gas from the discharge passage of the side jacket. Thereby, the stagnation of the blowing of gas is prevented, and the gas is easily distributed efficiently throughout the cavity.

  When the mold manufacturing apparatus has the side jacket, it is preferable that a pair of side jackets are mounted on the mold so as to face each other, and the pair of side jackets have the same shape. By mounting the pair of side jackets so as to face each other, the side jackets are mounted on both the first side surface and the second side surface of the mold, so that one of the first side surface or the second side surface is mounted. Compared with the case where only the side jacket is provided, a mold with no unevenness can be produced. Further, since the pair of side jackets have the same shape, the manufacturing cost of the side jacket can be reduced.

  The mold manufacturing apparatus has a recess opening on the abutting surface side and a jacket communication path capable of supplying gas from the gas supply means to the recess, and the molding die so as to cover the external opening of the upper surface communication path. It is preferable to further include an upper jacket configured to be attachable to the. As a result, it is necessary to change the shape of the cavity by changing the shape of the mold, and even when it is desired to form the upper surface communication path at a position suitable for the shape of the cavity, the opening of the recess can be covered. A desired location and a desired number of communication paths can be formed. Accordingly, a communication path that matches the shape of the cavity is provided, and a mold without unevenness can be manufactured.

  It is preferable that a plurality of upper communication passages are formed on the upper surface of the molding die, and the recesses are formed so as to cover the plurality of upper communication passages. Thereby, the supply of gas to the cavity can be performed efficiently and in a short time from the upper surface to the entire surface. In addition, since the isobaric gas is supplied from the concave portion of the jacket to the plurality of communication passages, it is possible to always supply a stable gas at the same pressure.

  The upper jacket is provided with a partition that divides a space formed by the recess into the jacket communication path side and the recess opening side, a through hole formed in the partition, and a protrusion projecting from the periphery of the through hole to the jacket communication path side. It is preferable to have a cylindrical body. As a result, even when gas is supplied to the upper jacket and moisture is generated in the recess of the upper jacket, the moisture can be prevented from entering the opening of the recess by the partition wall and the cylindrical body. It is possible to prevent moisture from entering the cavity.

  The gas supply means includes a branch portion branched upstream from a connection portion with the upper jacket, and an on-off valve that controls gas supply to the recess of the upper jacket downstream from the branch portion. It is preferable. As a result, the gas supply means and the concave portion of the upper jacket are connected by opening the on-off valve, and the gas supply means and the concave portion of the upper jacket are closed by closing the open / close valve. It is done.

  The upper jacket is preferably provided so that the gas in the recess can be discharged. Thereby, when the recessed part of an upper jacket is a non-communication state with a gas supply means, the gas from a cavity can be performed via the recessed part of an upper jacket.

  It is preferable that the mold manufacturing apparatus further includes suction means for sucking the gas in the concave portion of the upper jacket. Thereby, the stagnation of the blowing of gas is prevented, and the gas is easily distributed efficiently throughout the cavity.

  The mold manufacturing apparatus has a recess opening on the abutting surface side and a jacket communication path capable of supplying gas from the gas supply means to the recess, and the molding die so as to cover the external opening of the lower surface communication path. It is preferable to further include a lower jacket configured to be attachable to the. As a result, it is necessary to change the shape of the cavity by changing the shape of the mold, and even if it is desired to form the lower surface communication path at a position suitable for the shape of the cavity, the range in which the opening of the concave portion can be covered. A desired location and a desired number of communication paths can be formed. Accordingly, a communication path that matches the shape of the cavity is provided, and a mold without unevenness can be manufactured.

  It is preferable that a plurality of lower communication paths are formed on the lower surface of the molding die, and the recesses are formed so as to cover the plurality of lower communication paths. As a result, the gas can be supplied to the cavity efficiently and in a short time from the bottom surface. In addition, since the isobaric gas is supplied from the concave portion of the jacket to the plurality of communication passages, it is possible to always supply a stable gas at the same pressure.

  The gas supply means has a branching portion branched upstream from a connection portion with the lower jacket, and an on-off valve for controlling gas supply to the concave portion of the lower jacket downstream from the branching portion. It is preferable. As a result, the gas supply means and the recessed portion of the lower jacket can be communicated by opening the on-off valve, and the gas supply means and the recessed portion of the lower jacket can be disconnected from each other by closing the open / close valve. It is done.

  The lower jacket is preferably provided so that the gas in the recess can be discharged. Thereby, when the recessed part of a lower jacket is a non-communication state with a gas supply means, the gas from a cavity can be performed via the recessed part of a lower jacket.

  It is preferable that the mold manufacturing apparatus further includes suction means for sucking the gas in the concave portion of the lower jacket. Thereby, the stagnation of the blowing of gas is prevented, and the gas is easily distributed efficiently throughout the cavity.

  It is preferable that the gas supply means includes an air supply line, a water vapor supply line, a carbon dioxide supply line, and an on / off valve capable of switching and mixing these supply lines, and a heater is provided in the air supply line. . Thereby, the gas to supply can be selected by adjusting the on-off valve of each supply line, and multiple types of gas can be mixed. Furthermore, by providing a heater in the air supply line, the heated air can be supplied to the cavity, so that the heated air can be supplied when the coated sand is dried.

  It is preferable that a flow meter and a pressure reducing valve are provided in the air supply line, the water vapor supply line, and the carbon dioxide supply line. Thereby, while being able to adjust the flow volume, pressure, etc. of the gas supplied to a cavity, several types of gas can be mixed by a desired mixing ratio and can be supplied to a cavity.

  The mold manufacturing apparatus includes a storage tank in which the coated sand supply means supplies the coated sand to the cavity via a communication path, and a preheater that is disposed in the storage tank and preheats the coated sand. It is preferable. Thereby, the coated sand in the storage tank before being supplied to the cavity can be preheated, and moisture adhering to the surface of the coated sand can be removed.

  It is preferable that the gas supply unit includes a water vapor supply line, and the preheater uses water vapor diverted from the water vapor supply line as a heat source. Thereby, the water vapor supply means of the gas supply means for supplying to the cavity can be used as a heat source, and it is not necessary to prepare a separate heat source, and the cost of the mold manufacturing apparatus can be suppressed.

  As described above, when the preheater uses the steam separated from the steam supply line as the heat source, it is preferable to have a spiral hollow tube through which the steam flows. Thereby, the coated sand can be preheated evenly and efficiently by the spiral middle space.

  Preferably, the gas supply means includes an air supply line provided with a heater, and the preheater has an air ejection hole for ejecting air diverted from the air supply line after the heater. As a result, the coated sand can be preheated by blowing out heated air, and the coated sand can be prevented from becoming a dull state.

  Furthermore, a method for producing a mold according to the present invention includes a step of filling coated cavities of a mold of the mold production apparatus having the above-described configuration with a coated sand, a water vapor supplying step of supplying water vapor to the coated sand of the cavities by a gas supply means, And a drying step of drying the coated sand containing water vapor by the water vapor supply step.

  According to the mold manufacturing method, the same advantages as the mold manufacturing apparatus can be obtained. That is, by changing the communication path in communication with the gas supply means, it is possible to supply gas to the cavity easily and surely, thereby producing a mold without unevenness.

  In the water vapor supply step, it is preferable that water vapor is supplied from the upper surface communication path, the first side surface communication path, and the second side surface communication path, and the water vapor is discharged from the lower surface communication path. Thereby, the supply of water vapor to the cavity can be performed efficiently and in a short time.

  In the water vapor supply step, it is preferable that water vapor is supplied from the upper surface communication passage and water vapor is discharged from the first side surface communication passage, the second side surface communication passage, and the lower surface communication passage. Thereby, water vapor can be efficiently discharged from the cavity in a short time.

  As the water-soluble binder for covering the refractory aggregate forming the coated sand, it is preferable to use one or more of thermosetting resins, saccharides, proteins, synthetic polymers, salts and inorganic polymers. Thereby, solidification and hardening of the coated sand can be made effective.

  It is preferable to use an alkali phenol resin as a water-soluble binder that covers the fireproof aggregate forming the coated sand. As a result, the quality of the mold can be improved, and the working environment for mold production can be improved.

  As described above, the mold manufacturing apparatus and the mold manufacturing method according to the present invention provide a path so that gas can be accurately supplied to the cavity even when the shape of the cavity is changed according to the structure of the mold. A mold that can be easily changed and has no unevenness can be manufactured.

Schematic cross-sectional view showing a mold manufacturing apparatus according to the first embodiment of the present invention Schematic sectional view showing a reservoir and gas supply means of the mold manufacturing apparatus of FIG. Typical sectional drawing which shows the state before the filling process of the coated sand of the mold manufacturing apparatus of FIG. Schematic cross-sectional view showing the coated sand filling process of the mold manufacturing apparatus of FIG. Typical sectional drawing which shows the mold manufacturing apparatus which concerns on 2nd embodiment different from the mold manufacturing apparatus of FIG. Typical sectional drawing which shows the mold manufacturing apparatus which concerns on 3rd embodiment different from the mold manufacturing apparatus of FIG.1 and FIG.5. FIG. 1, FIG. 5 and FIG. 6 are schematic sectional views showing a mold manufacturing apparatus according to a fourth embodiment different from the mold manufacturing apparatus of FIG. The schematic diagram which shows the supply procedure of various gas of this invention The schematic diagram which shows the pattern of the supply and discharge | emission direction of the gas of this invention Schematic sectional view showing a conventional mold manufacturing apparatus Schematic sectional view showing a conventional mold manufacturing apparatus different from the mold manufacturing apparatus of FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

<First embodiment>
The mold manufacturing apparatus of the first embodiment shown in FIG. 1 includes a mold 3 having a cavity 8 that can be filled with a coated sand 7, a pair of side jackets 4 and 5 that are detachably attached to the mold 3; The apparatus further includes gas supply means that has the gas supply device 6 and supplies gas to the cavity 8, and coated sand supply means that has a storage tank 51 (see FIG. 2) that supplies the coated sand 7 to the cavity 8.

(Mold 3)
The mold 3 is composed of a fixed mold 1 attached to the fixed side and a movable mold 2 attached to the movable side in mold opening, and is a side-open mold. The molding die 3 has an upper surface communication path 9 and a lower surface communication path 10 that communicate with the cavity 8 and open to the upper surface and the lower surface. The fixed mold 1 and the movable mold 2 are closed in a pressurized state so that gas such as water vapor does not leak when the mold is closed.

  The mold 3 has a first side surface and a second side surface that face each other, and the mold 3 opens on the first side surface and the second side surface and communicates with the cavity 8. The second side communication passage 12 is provided. Further, a mesh 13 such as a wire mesh is disposed in the opening on the cavity 8 side of the lower surface communication path 10, the first side surface communication path 11, and the second side surface communication path 12, and the coated sand 7 filled in the cavity 8. Is in a state where it is difficult to enter the lower surface communication path 10, the first side surface communication path 11, and the second side surface communication path 12, and to allow ventilation. Although FIG. 1 shows a configuration in which four first series passages 11 and four second side surface communication paths 12 are provided, the locations and the number of formations of the first series passages 11 and the second communication paths 12 are illustrated. Is not particularly limited, and the formation location and number of the upper surface communication passage 9 and the lower surface communication passage 10 are not particularly limited, and if the communication passage is formed according to the shape of the mold to be manufactured. It ’s enough.

  The lower surface communication path 10 is provided so that the state of communication with the outside air can be changed. Specifically, the lower surface communication path 10 is provided with an opening / closing valve 16. The passage 10 is provided to open and close.

(Jacket)
The mold manufacturing apparatus includes a first side jacket 4 and a second side jacket 5 that are mounted on the first side surface and the second side surface. The first side jacket 4 has a substantially rectangular box shape as a whole, and has a recess 17 that opens on the mounting surface side of the mold 3. The first side jacket 4 is mounted on the mold 3 so that the external openings of the plurality of first side surface communication paths 11 are covered by the recesses 17. The first side jacket 4 has an abutting surface that is in close contact with the side wall of the molding die 3 (side surface of the fixed die 1) at the outer edge of the concave portion 17. It communicates only with the side surface communication path 11, a jacket communication path 23, which will be described later, and the discharge path 27. Here, the first side jacket 4 has, for example, a silicon seal ring disposed on the contact surface. In addition, the shape of the 1st side part jacket 4 is not limited, For example, a covered cylindrical shape etc. are employable.

  Further, the first side jacket 4 has a jacket communication passage 23 that supplies gas from the gas supply means to the recess 17. The jacket communication path 23 is formed on a wall surface (side wall of the first side jacket 4) facing the opening of the recess 17. This jacket communication path 23 is provided at one place in the center of the recess 17 in side view. Furthermore, the opening area of the jacket communication path 23 on the recess 17 side is smaller than the opening area on the mounting surface side of the recess 17. Here, the ratio of the opening area on the mounting surface side of the recess 17 to the opening area on the recess 17 side of the jacket communication path 23 is preferably 3 to 1000 times, more preferably 5 to 500 times, and more preferably 10 times. More preferably, it is 200 times or less. If the ratio of the opening areas is less than the lower limit value, the opening on the mounting surface side of the recess 17 becomes too small, and the area covered by the recess 17 (formation area of the first side surface communication path 11) may become too small. There is. On the other hand, if the ratio of the opening areas exceeds the upper limit, the concave portion 17 becomes too large, and the first side jacket 4 may become large and difficult to handle. In addition, the formation location etc. of the jacket communication path 23 are not limited, It is also possible to provide several jacket communication paths 23, and it is also possible to provide other than the center part of the side wall of the 1st side jacket 4. In addition, it can be formed on the upper surface of the recess 17.

  The said 1st side part jacket 4 has the discharge path 27 which can discharge | emit the gas of the recessed part 17, and this discharge path 27 is provided so that opening and closing is possible. The discharge path 27 has a discharge port 26 opened in the recess 17, and a pipe 58 is connected to the opposite side (downstream side) of the discharge path 27 of the discharge path 27, and an open / close valve 28 is attached to the pipe 58. ing. That is, the discharge path 27 is provided so as to be opened and closed by the opening / closing valve 28.

  The jacket communication passage 23 is provided so as to be opened and closed by an on-off valve 25 described later. Then, by opening / closing the on-off valves 25, 28, it is possible to select whether the first side surface communication path 11 is used as a gas supply path or a discharge path. By closing 28, the first side surface communication path 11 functions as a gas supply path, and by closing the on-off valve 25 and opening the on-off valve 28, the first side surface communication path 11 functions as an exhaust path.

  The second side jacket 5 is attached to the second side surface of the mold 3 so as to cover the opening on the outer side of the second side surface communication path 12. The second side jacket 5 is provided in the same shape as the first side jacket 4 in the left-right symmetry, and is mounted on the mold 3 so as to face the first side jacket 4. The second side jacket 5 has the concave portion 19, the space portion 20, the jacket communication path 31, and the discharge path 35, but since the configuration is the same as that of the first side jacket 4, a detailed description will be given. Omitted. Further, the discharge path 35 of the second side jacket portion 5 is also provided so as to be opened and closed by an on-off valve 36 attached to a pipe 59 to which the discharge path 35 is connected.

(Gas supply means)
The gas supply means includes the gas supply device 6 and also includes on-off valves 25 and 33 for changing the communication state between the gas supply device 6 and the recesses 17 and 19 of the side jackets 4 and 5. Specifically, the gas supply means includes pipes 24 and 32 connected to the gas supply device 6, and the on-off valves 25 and 33 connect the pipes 24 and 32 and the jacket communication passages 23 and 31 together with a flow path. Is arranged to open and close. The on-off valves 25 and 33 are attached to the side jackets 4 and 5, specifically, attached to the inlets 22 and 30 (side openings) of the jacket communication passages 23 and 31.

  Further, the gas supply means includes an on-off valve 15 for changing the communication state between the gas supply device 6 and the upper surface communication passage 9. Specifically, the gas supply means includes a pipe 14 connected to the gas supply device 6, and the on-off valve 15 is arranged to connect the pipe 14 and the upper surface communication path 9 and to open and close the flow path. Yes.

  The gas supply device 6 is a device for supplying a gas such as water vapor to the concave portions 17 and 19 of the side jackets 4 and 5. As shown in FIG. 2, the gas supply device 6 includes a water vapor supply line 39 for supplying water vapor to the pipes 24 and 32 connected to the jacket communication passages 23 and 31 of the side jackets 4 and 5. An air supply line 37 that supplies air to 24 and 32 and a carbon dioxide supply line 38 that supplies carbon dioxide to the pipes 24 and 32 are provided.

  The air supply line 37, the carbon dioxide supply line 38, and the water vapor supply line 39 have opening / closing valves 47, 48, 49, flow meters 40, 43, 45, and pressure reducing valves 41, 44, 46, respectively. Further, the air supply line 37 has a heater 42.

  The gas supply means includes a mixing unit 50 having a space where each gas can be mixed, and the gas supplied to the pipes 24 and 32 can be switched or the amount of gas can be adjusted by the on-off valves 47, 48, and 49. In addition, gas can be mixed by the mixing unit 50. The flow meters 40, 43, 45 and the pressure reducing valves 41, 44, 46 are formed so that gas is supplied at a predetermined constant pressure. Further, the heater 42 can heat the air, thereby supplying heated air.

  Further, the air supply line 37 and the water vapor supply line 39 are branched and connected to piping (described later) connected to the storage tank 51.

(Coated sand supply means)
The coated sand supply means includes a storage tank 51 as shown in FIGS. 2 to 4, and the storage tank 51 is formed in a cylindrical shape and the lower part is a mortar shape. A discharge port 52 provided (not shown) is formed.

  As shown in FIG. 2, the coated sand supply means is provided in a storage tank 51 and has a preheater for preheating the coated sand (not shown in FIGS. 3 and 4). The preheater includes a heat exchanger 55 and a flow gas branch pipe 54. The heat exchanger 55 uses the steam branched from the steam supply line 39 as a heat source, and has a spiral hollow tube through which the steam flows. Specifically, the hollow tube is disposed in a spiral shape so as to surround the axis of the storage tank 51. In addition, the hollow tube of the heat exchanger 55 may be formed in a plurality of middle spaces in tandem, in parallel, or concentrically in order to structurally improve heat exchange capability. Further, as a spiral shape, it may be provided in a conical shape, a cylindrical shape, and a drum shape, may be provided in a plane spiral shape, or may be formed in an elliptical shape or a rectangular shape.

  The hollow tube of the heat exchanger 55 is not particularly limited as long as it has a good thermal conductivity. For example, a metal, ceramic, fiber reinforced plastic, or plastic can be used. More preferred.

  One end of the heat exchanger 55 is connected to a pipe connected to the steam supply line 39, and the other end is led out of the storage tank 51. The supplied water vapor is discharged to the outside.

  The flowing gas branch pipe 54 has an air ejection hole 53 for ejecting air diverted from the air supply line 37 after the heater 42. The flow gas branch pipe 54 is connected to the air supply line 37 and is connected to the straight pipe portion 56 disposed at the axial position of the storage tank 51, and has a different diameter formed in a ring shape at the lower end portion of the straight pipe portion 56. The two annular pipe portions 57, a branch pipe branched from the straight pipe portion 56, and a connecting pipe connecting the straight pipe portion 56 and the two annular pipe portions 57 are provided. The straight pipe portion 56, the annular pipe portion 57, the branch pipe and the connection pipe are formed by hollow pipes, and are connected to the connection pipe from the branch pipe branched from the straight pipe portion 56, and the air supply line 37. More heated air is supplied. Further, the straight pipe portion 56, the annular pipe portion 57, the branch pipe and the connecting pipe are not particularly limited, but may be any one having good thermal conductivity, for example, using metal, ceramic, fiber reinforced plastic, or plastic. It can be made of copper having a high thermal conductivity.

  A plurality of air ejection holes 53 are formed in the annular tube portion 57. The air ejection holes 53 are preferably formed on the lower side of the annular tube portion, and more preferably formed obliquely below or directly below. As a result, clogging due to the inflow of the coated sand 7 into the pipe or a short path of heated air is less likely to occur. Further, the air ejection holes 53 are provided in the annular tube portion 57 at equal intervals. Although it does not specifically limit as a hole diameter of the air ejection hole 53, It is preferable that they are 0.3 mm or more and 6 mm or less.

  The shape of the flow gas branch pipe 54 is not particularly limited as long as the air ejection hole 53 can be ejected from the lower portion of the storage tank 51.

(Coated sand)
The coated sand 7 that fills the cavity 8, a refractory aggregate, and a water-soluble binder that covers the refractory aggregate are formed.

  As the refractory aggregate, various refractory aggregates conventionally used for molds can be used. Specifically, silica sand, chromite sand, zircon sand, olivine sand, alumina sand, synthetic mullite sand and the like can be used. Further, these refractory aggregates may be fresh sand, reclaimed sand or recovered sand that has been used once or a plurality of times for molding as a casting sand, or a mixed sand thereof. As a particle size of the said refractory aggregate, the particle size of 40 or more and 80 or less is preferable in AFS index, More preferably, the particle size of 50 or more and 70 or less is more preferable.

  The water-soluble binder is also called a binder, and as the water-soluble binder, thermosetting resins, saccharides, proteins, synthetic polymers, salts, and inorganic polymers can be used. These may be used alone or in combination of two or more.

  As the thermosetting resin used as the water-soluble binder, a phenol resin such as a resol type, a novolac type or a benzylic ether type, a furan resin, an isocyanate compound, an amine polyol resin, a polyether polyol resin, or the like can be used. As the curing agent added to these resins, isocyanate compounds, organic esters, hexamethylenetetramine and the like can be used, and tertiary amines, pyridine derivatives, organic sulfonic acids and the like can be used as the curing catalyst.

  Moreover, among the said thermosetting resins, a phenol resin is preferable. This phenol resin can be prepared by reacting phenols and formaldehyde in the presence of a reaction catalyst.

  The phenols are phenols or phenol derivatives. For example, in addition to phenol, trifunctional compounds such as m-cresol, resorcinol and 3,5-xylenol, tetrafunctional compounds such as bisphenol A and dihydroxydiphenylmethane, o-cresol, p-cresol, p-ter- Bifunctional o- or p-substituted phenols such as butylphenol, p-phenylphenol, p-cumylphenol, p-nonylphenol, 2,4 or 2,6-xylenol can be used, and chlorine or A halogenated phenol substituted with bromine can also be used. These may be used alone or in combination.

  Formaldehydes may be used in the form of formaldehyde, paraformaldehyde, acetaldehyde, benzaldehyde, trioxane, tetraoxane, or a part of formaldehyde may be replaced with furfural or furfuryl alcohol. Among these, formaldehydes are optimally used in the form of an aqueous solution, and formalin is mentioned as a suitable one.

  The blending ratio of the above phenols and formaldehydes is preferably such that the molar ratio of phenols to formaldehyde is in the range of 1: 0.6 to 1: 3.5, and 1: 1.5 to 1: 2. A range of 5 is more preferable.

  As a reaction catalyst used for a thermosetting resin, for example, when preparing a novolac type phenol resin, an inorganic acid such as hydrochloric acid, sulfuric acid or phosphoric acid, or an oxalic acid, paratoluenesulfonic acid, benzenesulfonic acid, xylenesulfonic acid, etc. It is preferable to use an organic acid, further zinc acetate or the like. Moreover, when preparing a resol type phenol resin, an oxide or hydroxide of alkali metal and / or alkaline earth metal can be used, and dimethylamine, triethylamine, butylamine, dibutylamine, tributylamine, diethylenetriamine, Use of aliphatic primary, secondary, and tertiary amines such as dicyandiamide, aliphatic amines having an aromatic ring such as N, N-dimethylbenzylamine, aniline, 1,5-naphthalenediamine, etc. It is preferable to use divalent metal naphthenic acid, divalent metal hydroxide, and the like such as aromatic amine, ammonia, hexamethylenetetramine and the like.

  Moreover, when diluting and using a phenol resin, you may use alcohols, ketones, ester, polyhydric alcohol, etc. as a solvent for dilution.

  As an example of the phenol resin, a water-soluble alkali phenol resin (resole resin) can be suitably used. The water-soluble alkaline phenol resin means that in the presence of a large amount of an alkaline substance, for example, in a ratio that the number of moles of the alkaline substance relative to the phenol is about 0.01 to 2.0 times mole, It is an alkaline phenol resin (resole resin) obtained by making it react. Examples of the alkaline substance include alkali metal hydroxides such as sodium hydroxide, potassium hydroxide, and lithium hydroxide, and these are used alone or in combination of two or more.

  As the saccharide used as the water-soluble binder, monosaccharides, oligosaccharides, polysaccharides, and the like can be used. From various monosaccharides, oligosaccharides, polysaccharides, one kind can be selected and used alone or in combination. May be used in combination.

  As monosaccharides, glucose (glucose), fructose (fructose), galactose, and the like can be used. As oligosaccharides, disaccharides such as maltose (malt sugar), sucrose (sucrose), lactose (lactose), and cellobiose are used. be able to.

  As the polysaccharide, starch sugar, dextrin, xanthan gum, curdlan, pullulan, cycloamylose, chitin, cellulose, starch and the like can be used. As the starch, raw starch and processed starch can be used. Specifically, potato starch, corn starch, high amylose, sweet potato starch, tapioca starch, sago starch, rice starch, amaranthus starch can be used as raw starch, roasted dextrin, enzyme-modified dextrin, Acid-treated starch, oxidized starch, and dialdehyde-modified starch can be used. In addition, carboxymethyl starch, hydroxyalkyl starch, cationic starch, methylolated starch, etc. can be used as etherified starch. Higher fatty acid esterified starch can be used. Furthermore, cross-linked starch, kraft starch, wet heat-treated starch and the like can also be used.

  In addition to the above, gum arabic, tragacanth gum, xanthan gum, guar gum, locust bean gum, gellan gum, alginic acid, carrageenan, semi-synthetic polymer methylcellulose, ethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, methylhydroxypropylcellulose, ethylhydroxyethylcellulose, carboxy Gummy gums such as methylcellulose and cationized cellulose may be used.

  Carboxylic acid may be used as a curing agent for saccharides, particularly polysaccharides. The carboxylic acid is not particularly limited, and oxalic acid, maleic acid, succinic acid, citric acid, butanetetradicarboxylic acid, methyl vinyl ether-maleic anhydride copolymer, and the like can be used.

  As the protein used as the water-soluble binder, gelatin, glue or the like can be used.

  Synthetic polymers used as water-soluble binders include polyethylene oxide, poly-α-hydroxyacrylic acid, acrylic acid copolymer, acrylic ester copolymer, methacrylate ester, nonionic polyacrylamide, anionic poly Acrylamide, cationic polyacrylamide, polyaminoalkyl methacrylate, acrylamide / acrylic acid copolymer, polyvinyl sulfonic acid, polystyrene sulfonic acid, sulfonated maleic acid, polyvinyl alcohol, polyvinyl pyrrolidone, polyethylene glycol, polyvinyl methyl ether, polyether modified silicone, Alternatively, these modified products can be used. These may be used alone or in combination.

  Salts used as water-soluble binders include metal chlorides such as lithium, sodium, potassium, magnesium, calcium, zinc, iron, titanium, aluminum, bromides, carbonates, sulfates, borates, phosphates, Inorganic salts such as silicates can be used.

  As the inorganic polymer used as the water-soluble binder, water glass, colloidal silica, alkyl silicate, bentonite, cement and the like can be used.

  The amount of the refractory aggregate and the water-soluble binder is preferably 0.3 to 5 parts by mass in terms of solid content with respect to 100 parts by mass of the refractory aggregate. More preferably, it is blended at a ratio of 5 parts by mass or more and 3 parts by mass or less.

  In addition, the coated sand 7 has a room temperature fluidity by kneading or mixing a refractory aggregate and a water-soluble binder, coating the surface of the refractory aggregate with a water-soluble binder, and then evaporating the water of the water-soluble binder. A dry powdery water-soluble binder-coated refractory aggregate having Such water transpiration of the water-soluble binder needs to be carried out quickly before the water-soluble binder is cured. Generally, the water content is blown off within 5 minutes, preferably within 2 minutes, to dry powder. Water-soluble binder-coated refractory aggregate.

  As one means for rapidly evaporating the water content of the water-soluble binder, there is a method of kneading or mixing a preheated refractory aggregate and a water-soluble binder. By kneading or mixing the preheated refractory aggregate and the water-soluble binder, the water content of the water-soluble binder rapidly evaporates with the heat of the heated refractory aggregate. Thus, the dry coated sand 7 having room temperature fluidity can be suitably obtained. The preheating temperature of the refractory aggregate is appropriately selected according to the water content of the water-soluble binder, the blending amount thereof, etc., but is heated to a temperature of 100 ° C. or higher and 140 ° C. or lower. Is preferred. If the preheating temperature is too low, water cannot be effectively evaporated, and if the preheating temperature is too high, the water-soluble binder may be cured.

  The coated sand 7 formed as described above preferably has a moisture content of 0.5% by mass or less, and more preferably 0.3% by mass or less. As a result, the powder becomes a dry powder and becomes coated sand 7 having excellent properties with room temperature fluidity.

(Mold manufacturing method)
Next, a mold manufacturing method using the mold manufacturing apparatus according to the first embodiment will be described with reference to FIGS. 1, 3, and 4.

  The mold manufacturing method using the mold manufacturing apparatus includes a filling step of filling the coated sand 7 into the cavity 8 of the mold 3, a water vapor supplying step of supplying water vapor to the coated sand 7 of the cavity 8 by gas supply means, and water vapor It has a drying step of drying the wet 9 coated sand 7 containing water vapor in the supplying step. In addition, the mold manufacturing method includes a selection step for selecting a supply / exhaust path in the cavity 8.

  The filling process will be described. First, before the coated sand 7 built in the storage tank 51 is filled into the cavity 8, the coated sand 7 is preheated by a preheater. The temperature at which the coated sand 7 is preheated by the preheater is preferably 30 ° C. or higher, more preferably 60 ° C. or higher and 80 ° C. or lower. When the preheating temperature is equal to or higher than the above temperature, moisture can be efficiently removed. When the preheating temperature is equal to or lower than the above temperature, strength reduction due to deterioration of the coated sand can be prevented.

  Next, as shown in FIG. 4, the lower discharge port 52 of the storage tank 51 in which the coated sand 7 is stored is connected to the upper surface communication path 9 of the mold 3. When a plurality of upper surface communication paths 9 are formed, an upper connection port connected to the discharge port 52 of the storage tank 51 and a plurality of lower connection ports connected to the upper surface communication path 9 corresponding to the plurality of upper surface communication paths 9. It is also possible to use a blow head (not shown) having

  Then, the coated sand 7 is filled into the cavity 8 of the mold 3. At this time, the inside of the storage tank 51 is sealed and air is blown into the storage tank 51 or air is blown in the vicinity of the discharge port 52 to pressurize the inside of the storage tank 51, and the coated sand 7 is blown into the cavity 8 by air pressure. It may be filled with. Since the openings of the lower surface communication path 10, the first side surface communication path 11, and the second side surface communication path 12 are closed by the net 13, the coated sand 7 is difficult to leak from each opening.

  Next, a selection process, a water vapor supply process, and a drying process will be described. This selection process is a process of selecting from which communication path the gas supplied in the water vapor supply process and the drying process is supplied and discharged. The water vapor supply step is a step of supplying water vapor to the coated sand 7 of the cavity 8 through the communication path. The drying step is a step of drying, solidifying and curing the coated sand 7 by supplying carbon dioxide and heated air to the coated sand 7 wetted with water vapor. Note that the selection step can be performed before the filling step described above.

  The supply and exhaust paths of the gas in the cavity 8 in the water vapor supply process and the drying process are determined by the selection of the supply and discharge communication paths in the selection process. The air supply / exhaust path is set by opening and closing the on-off valves 15, 16, 25, 28, 33, 36 connected to the upper surface communication path 9, the lower surface communication path 10 and the side jackets 4, 5.

  The gas supply and exhaust patterns that can be performed by the mold manufacturing apparatus of the first embodiment will be described with reference to FIG. The upper surface communication path 9 is supplied with gas when the on-off valve 15 is opened, and is neither supplied nor exhausted when closed. When the opening / closing valve 16 is opened, the gas is exhausted from the lower surface communication path 10, and neither supply nor exhaust is performed when it is closed. Water vapor is supplied to the first side surface communication path 11 by opening the on-off valve 25 and closing the on-off valve 28, and exhausting is performed by closing the on-off valve 25 and opening the on-off valve 28. Further, supply and exhaust are not performed by closing the on-off valves 25 and 28. Gas is supplied to the second side surface communication path 12 by opening the opening / closing valve 33 and closing the opening / closing valve 36, and exhausting is performed by closing the opening / closing valve 33 and opening the opening / closing valve 36. Further, supply and exhaust are not performed by closing the on-off valves 33 and 35.

  There are 21 patterns for supplying and exhausting gas, which are shown in FIGS. 9 (a) to 9 (u). In FIG. 9A, gas is supplied from the upper surface communication path 9, the first side surface communication path 11, and the second side surface communication path 12, and exhausted from the lower surface communication path 10. In FIG. 9B, gas is supplied from the upper surface communication path 9, and exhaust is performed from the lower surface communication path 10, the first side surface communication path 11, and the second side surface communication path 12. In FIG. 9C, gas is supplied from the upper surface communication path 9 and the second side surface communication path 12, and exhaust is performed from the lower surface communication path 10 and the first side surface communication path 11. In FIG. 9D, gas is supplied from the upper surface communication path 9 and the first side surface communication path 11, and exhaust is performed from the lower surface communication path 10 and the second side surface communication path 12. In FIG. 9 (e), gas is supplied from the first side surface communication path 11 and the second side surface communication path 12 and exhausted from the lower surface communication path 10. In FIG. 9 (f), gas is supplied from the second side surface communication path 12, and exhaust is performed from the lower surface communication path 10 and the first side surface communication path 11. In FIG. 9G, gas is supplied from the first side surface communication passage 11 and exhaust is performed from the lower surface communication passage 10 and the second side surface communication passage 12. In FIG. 9 (h), gas is supplied from the upper surface communication path 9, and exhaust is performed from the lower surface communication path 10 and the first side surface communication path 11. In FIG. 9 (i), gas is supplied from the upper surface communication path 9 and exhausted from the lower surface communication path 10 and the second side surface communication path 12. In FIG. 9 (j), gas is supplied from the upper surface communication path 9 and the first side surface communication path 11 and exhausted from the lower surface communication path 10. In FIG. 9 (k), gas is supplied from the upper surface communication path 9 and the second side surface communication path 12 and exhausted from the lower surface communication path 10. In FIG. 9 (l), gas is supplied from the upper surface communication path 9 and exhaust is performed from the first side surface communication path 11 and the second side surface communication path 12. In FIG. 9 (m), gas is supplied from the upper surface communication path 9 and the second side surface communication path 12 and exhausted from the first side surface communication path 11. In FIG. 9 (n), gas is supplied from the upper surface communication path 9 and the first side surface communication path 11 and exhausted from the second side surface communication path 12. In FIG. 9 (o), gas is supplied from the upper surface communication path 9 and exhausted from the lower surface communication path 10. In FIG. 9 (p), gas is supplied from the second side surface communication path 12 and exhausted from the first side surface communication path 11. In FIG. 9 (q), water vapor is supplied from the first side surface communication passage 11 and exhausted from the second side surface communication passage 12. In FIG. 9 (r), gas is supplied from the upper surface communication path 9 and exhausted from the first side surface communication path 11. In FIG. 9 (s), gas is supplied from the upper surface communication path 9 and exhausted from the second side surface communication path 12. In FIG. 9 (t), gas is supplied from the first side surface communication path 11 and exhausted from the lower surface communication path 10. In FIG. 9 (u), gas is supplied from the second side surface communication path 12 and exhausted from the lower surface communication path 10. Note that FIG. 9A and FIG. 9B are preferably used for the supply and exhaust of water vapor.

  In the case of FIG. 9A, gas is supplied from the upper surface communication path 9, the first side surface communication path 11, and the second side surface communication path 12, and the gas is discharged from the lower surface communication path 10. Specifically, only the on-off valves 28 and 36 on the discharge side of the side jackets 4 and 5 are closed, and the other on-off valves 15, 16, 25 and 33 are opened. When the gas is supplied from the gas supply means, the gas is supplied from the upper surface communication path 9 to the cavity 8 and is also supplied to the spaces 18 and 20 via the jacket communication paths 23 and 31 of the side jackets 4 and 5. The gas in the space portions 18 and 20 is supplied to the cavity 8 via the first side surface communication path 11 and the second side surface communication path 12. The gas supplied to the cavity 8 is exhausted from the lower surface communication path 10. For this reason, when producing a comparatively long and compact mold, water vapor can be supplied efficiently and uniformly, and molding can be performed in a short time.

  In the case of FIG. 9B, the gas is supplied from the upper surface communication path 9, and the gas is discharged from the first side surface communication path 11, the second side surface communication path 12, and the lower surface communication path 10. Specifically, only the on-off valves 25 and 33 on the supply side of the side jackets 4 and 5 are closed, and the other on-off valves 15, 16, 28 and 36 are opened. The gas supplied to the cavity 8 is exhausted from the lower surface communication passage 10 and exhausted to the space portions 18 and 20 of the side jackets 4 and 5 through the first side surface communication passage 11 and the second side surface communication passage 12. Then, the gas in the space portions 18 and 20 is exhausted through the discharge paths 27 and 35. For this reason, in the case of producing a comparatively long and compact mold, it is possible to supply and exhaust water vapor efficiently and uniformly and to perform molding in a short time.

  The procedure for supplying water vapor, carbon dioxide and heated air described above is to supply each gas in turn as shown in FIG. On the other hand, the gas may be supplied as a mixed gas. For example, as shown in FIG. 8B, water vapor and carbon dioxide are supplied in the first stage, and carbon dioxide and heated air are supplied in the second stage. It is also possible to supply only heated air in the third stage. Further, as shown in FIG. 8C, water vapor, carbon dioxide and heated air are supplied in the first stage, carbon dioxide and heated air are supplied in the second stage, and heated air is supplied in the third stage. Alternatively, as shown in FIG. 8D, water vapor and carbon dioxide may be supplied in the first stage, carbon dioxide may be supplied in the second stage, and heated air may be supplied in the third stage. Alternatively, as shown in FIG. 8 (e), water vapor may be supplied in the first stage, carbon dioxide and heated air may be supplied in the second stage, and heated air may be supplied in the third stage. As shown in f), water vapor may be supplied in the first stage, carbon dioxide may be supplied in the second stage, heated air may be supplied after a certain time, and heated air may be supplied in the third stage. As shown in (b) to (f) of FIG. 8, by mixing and supplying the respective gases, the action of the respective gases proceeds simultaneously, and the gas supply time can be shortened. As described above, the order of the gases supplied from the gas supply means may be any combination as long as the steam is supplied first, the supply of water vapor is stopped in the middle, and the supply of heated air is finally supplied. Good. Therefore, the water vapor supply step and the drying step may be performed in parallel. Note that, depending on the water-soluble binder used, the coated sand 6 is solidified or cured from the steam supply step to the drying step, or in the drying step.

  In addition, although the coated sand 7 is neutralized by supplying carbon dioxide, and solidification and hardening of the coated sand 6 are promoted, a water-soluble binder that does not require a neutralizing reaction by supplying carbon dioxide is used. In the case of the coated sand 7, the supply of carbon dioxide may be omitted. Moreover, when drying, solidification, and hardening of the coated sand 7 is performed by a method other than heated air, the supply of heated air may be omitted.

  The supply of water vapor by the gas supply means is preferably performed at a pressure of 0.03 Mpa or more and 0.5 Mpa or less, and more preferably 0.05 Mpa or more and 0.15 Mpa or less. The temperature of the supplied water vapor is preferably 80 ° C. or higher and 120 ° C. or lower, and more preferably 95 ° C. or higher and 105 ° C. or lower. In this case, the water supply time in the first stage is preferably 3 seconds or longer and 30 seconds or shorter, and more preferably 5 seconds or longer and 15 seconds or shorter.

  The supply of carbon dioxide by the gas supply means is preferably supplied at a pressure of 0.03 Mpa or more and 0.5 Mpa or less, and more preferably 0.1 Mpa or more and 0.3 Mpa or less. Moreover, the temperature of the carbon dioxide supplied is preferably from room temperature to 60 ° C., more preferably from 40 ° C. to 60 ° C. Thereby, the temperature change in the cavity 8 can be suppressed. The supply amount of carbon dioxide per hour is preferably 100 liters / second or less, and more preferably 5 liters / second or more and 30 liters / second or less. The carbon dioxide supply time at this time is preferably 5 seconds or more and 60 seconds or less.

  Supply of heated air by the gas supply means is preferably performed at a pressure of 0.03 Mpa or more and 0.5 Mpa or less, and more preferably 0.05 Mpa or more and 0.25 Mpa or less. Further, the temperature of the supplied heated air is preferably 60 ° C. or higher and 200 ° C. or lower, and more preferably 120 ° C. or higher and 160 ° C. or lower. Thereby, the coated sand 7 in the cavity 8 can be effectively dried. The supply amount of heated air per hour is preferably 30 liters / second or more and 400 liters / second or less. The supply time of the heated air at this time is preferably 15 seconds or more and 180 seconds or less. These gas conditions are not particularly limited because they vary depending on the size of the mold.

(advantage)
In the mold manufacturing apparatus, the gas supplied from the gas supply means as described above is supplied to the cavity 8 through the communication path in communication with the gas supply means, and at least one kind of gas in the cavity 8 is provided. It is exhausted from the communication path. And since the said upper surface communication path 9, the 1st side surface communication path 11, and the 2nd side surface communication path 12 are connected to the gas supply means so that the communication state can be changed, the said mold manufacturing apparatus is connected with these three types of communication paths. Of these, a communication path suitable for the structure of the mold or the like is communicated with the gas supply means, and gas can be supplied to the cavity 8 from this communication path. For this reason, it becomes possible to supply a gas that matches the shape of the cavity, and it is possible to manufacture a mold without unevenness. In other words, the mold manufacturing apparatus changes the shape of the cavity 8 according to the structure of the mold, etc., and by changing the communication path in communication with the gas supply means, it is possible to easily and surely obtain an accurate cavity. Thus, a mold without unevenness can be produced.

  Further, the mold manufacturing apparatus is provided so as to be able to exhaust the gas in the cavity 8 through at least two kinds of communication passages. Specifically, the lower surface communication passage 10, the first side surface communication passage 11, and the second side surface communication are provided. Since the passage 12 is connected to the outside air so that the communication state can be changed, a communication passage suitable for the mold structure or the like is communicated with the outside air among the three kinds of communication passages, and the gas is cavityd through the communication passage. 8 can be exhausted. For this reason, it becomes possible to exhaust the gas in conformity with the shape of the cavity 8, and a mold without unevenness can be manufactured. In other words, the mold manufacturing apparatus changes the shape of the cavity 8 according to the structure of the mold, and the gas to the cavity can be easily and reliably changed by changing the communication path in communication with the outside air. Supply can be performed, and thereby a mold without unevenness can be produced.

  In the mold manufacturing apparatus, the gas supplied from the gas supply means is supplied to the space portions 18 and 20 formed by the concave portions 17 and 19 of the side jackets 4 and 5 through the jacket communication passage 23. The gas supplied to the spaces 18 and 20 can be supplied to the cavity 8 via the plurality of first side surface communication passages 11 or the second side surface communication passages 12. Further, by opening / closing the on-off valves 25, 28, 33, and 36, the cavity 8 can be exhausted to the space portions 18 and 20 through the plurality of first side surface communication passages 11 or the second side surface communication passages 12, and the space portions 18, 20 Twenty gases can be exhausted through the exhaust passages 27 and 35. For this reason, when the shape of the cavity 8 is changed by changing the shape of the mold, the first side surface communication passage 11 and the second side surface communication passage 12 can be formed in the region covered with the recesses 17 and 19. The first side surface communication path 11 and the second side surface communication path 12 can be easily disposed at a position suitable for the shape. Therefore, a mold without unevenness can be manufactured by the first side surface communication path 11 and the second side surface communication path 12 arranged at a desired position.

  Furthermore, since the gas supply means includes a water vapor supply line 39, a carbon dioxide supply line 38, an air supply line 37, and a switching valve that can switch and mix these supply lines, the gas in each supply line is switched. Or a plurality of gases can be selected and mixed. Further, since the flow meters 40, 43, 45 and the pressure reducing valves 41, 44, 46 are provided in each supply line, gas can be supplied to the cavity 8 of the mold 3 at a constant pressure.

  Moreover, the mold manufacturing apparatus which is 1st embodiment has the preheater in the storage tank 51, Therefore The water | moisture content adhering to the surface of the coated sand 7 can be removed, without almost deteriorating the coated sand. And the fluidity of the coated sand can be further enhanced. Moreover, the dew condensation water produced when water vapor | steam is supplied can be decreased. Then, the coated sand 7 around the heat exchanger 55 is subjected to heat exchange evenly and efficiently by the heat exchanger 55, so that preheating to a desired temperature can be smoothly performed, and the heat exchanger formed in a spiral shape. 55 and the flow gas branch pipe 54 can effectively promote downward movement due to the weight of the coated sand 7 and prevent the coated sand 7 from adhering to the heat exchanger 55 and the like. The coated sand 7 can be smoothly discharged from 51 to the cavity 8 of the mold 3. The heated air blown out by the flow gas branch pipe 54 and the coated sand 7 are heat-exchanged, and further, heat-exchanged with the coated sand 7 in contact with the coated sand 7 flowing by the blown-up heated air, whereby the coated sand 7 7 can be preheated to the desired temperature. Furthermore, since the coated sand 7 is preheated in a fluidized state by blowing out heated air, there is little possibility that the coated sand 7 will be in a dull state or a preheating bias will occur.

  Moreover, as a water-soluble binder which coat | covers the fireproof aggregate which forms the coated sand 7, it coats by using 1 or 2 or more out of a thermosetting resin, saccharides, protein, a synthetic polymer, salts, or an inorganic polymer. Sand 7 can be effectively solidified and cured, and by using an alkaline phenolic resin, the quality of the mold to be produced can be improved with fewer defects, and the mold manufacturing work environment has less odor odor during molding. Can be improved.

<Second embodiment>
Next, the mold manufacturing apparatus of the second embodiment will be described with reference to FIG.

  The mold manufacturing apparatus shown in FIG. 5 includes an upper jacket 61, a lower jacket 70, a first side jacket 4, and a second side jacket 5 on the upper surface side, lower surface side, first side surface side, and second side surface side of the mold 3. have. Since the 1st side part jacket 4 and the 2nd side part jacket 5 are the structures similar to 1st embodiment, the description is abbreviate | omitted.

  The upper jacket 61 is formed so as to cover the external opening of the upper surface communication path 64. The upper jacket 61 has a recess 62 formed on the attachment surface of the mold and a jacket communication path 67 for supplying gas to a space 63 formed by the recess. In addition, the arrangement | positioning location and the number of arrangement | positioning of the upper surface communication path 64 may be formed according to the shape of the shaping | molding die 3 and the cavity 8, and should just be connected to the space part 63 and the cavity 8. FIG. The jacket communication path 67 and the upper surface communication path 64 of the upper jacket 61 communicate with each other via the space 63, and the inlet 66 of the jacket communication path 67 can be opened and closed via an opening / closing valve 69. 68.

  The lower jacket 70 is formed to cover the external opening of the lower surface communication path 73 of the mold. The lower jacket 70 has a recess 71 formed on the attachment surface of the mold, and a jacket communication path 76 for discharging gas from a space 72 formed by the recess 71. In addition, the arrangement | positioning location and number of arrangement | positioning of the lower surface communication path 73 may be formed according to the shape of the shaping | molding die 3 and the cavity 8, and should just be connected to the space part 72 and the cavity 8. FIG. The jacket communication path 76 and the lower surface communication path 73 of the lower jacket 70 communicate with each other via a space 72, and the discharge path 75 of the jacket communication path 76 is connected to a pipe 78 through an on-off valve 77 so as to be opened and closed. Yes. The pipe 78 is branched and connected to the discharge paths 27 and 35 of the first side jacket 4 and the second side jacket 5, and is formed so that the gases discharged from the respective discharge paths merge. . Further, a suction machine 79 is disposed on the downstream side of the joining portion of the pipe 78, and sucks and discharges the gas discharged to the molding die. Note that the suction device 79 may be disposed in a pipe connected to each discharge path.

  In the mold manufacturing apparatus of the second embodiment, the gas is supplied from the gas supply means through the jacket communication passage 67 to the space 63 of the upper jacket 61, and the gas supplied to the cavity is the space of the lower jacket 70. 72 is discharged to the pipe 78 through the discharge path 75. About the 1st side surface communication path 11 and the 2nd side surface communication path 12, either supply or discharge | emission of gas can be selected.

  Further, the upper jacket 61 is detachable and can be attached to the molding die 3 when supplying gas, and may be attached to the distal end portion of the pipe 68 from the gas supply means. It may be provided so that it can be automatically switched to the installation of 51. In addition, a seal ring made of silicon is disposed at a position where the upper jacket 61 and the lower jacket 70 are in contact with the mold 3 to seal the space portions 63 and 72.

  In the mold manufacturing apparatus of the second embodiment, after the coated sand 7 is filled in the mold 3 and the storage tank 51 is removed, the upper jacket 61 disposed in the pipe 68 from the gas supply means is attached to the mold 3. Attached to the upper surface side, the jacket communication path 67 and the upper surface communication path 64 are communicated with the space 63. Thereafter, the on-off valve 69 is opened, and gas is supplied from the gas supply means into the mold 3. The supplied gas is sent into the space 63 through the jacket communication path 67 and blown into the cavity 8 from the space 63 through the communication path 64. The gas blown into the cavity 8 collects in the space portion 72 of the lower jacket, and then is discharged from the discharge path 75 through the jacket communication path 76. The discharged gas is sucked by the suction machine 79 and discharged to the outside.

  By using the mold manufacturing apparatus according to the second embodiment, gas is blown from the upper surface communication path 64 through the space 63 formed by the recess 62 of the upper jacket 61, so that the exterior of the plurality of upper surface communication paths 64 It is not necessary to provide a flow path that communicates with each of the side openings, and even if the mold 3 is replaced and the shape of the communication path of another mold is different, the communication path is made to communicate with the space 63 and the same. An upper jacket 61 can be used. In addition, since the exhausted gas is collected in the space portion 72 and then exhausted through the jacket communication path 76, a flow path that communicates with each of the external openings of the plurality of lower surface communication paths 73 is provided. Even if the mold 3 is replaced and the shape of the communication path of another mold is different, the same lower jacket 70 can be used if the communication path is communicated with the space portion 72. Further, since the gas is sucked by the suction device 79 and discharged to the outside, the stagnation of the gas blowing in the cavity 8 can be prevented, the gas can be efficiently distributed throughout the cavity 8, and the ventilation in the cavity 8 can be prevented. It can be ventilated even in bad places. In particular, since the cavity 8 of the mold 3 for a mold having a complicated shape also has a complicated structure, the ventilation of the cavity 8 having such a structure can be performed without any delay. As a result, molding defects of the mold are unlikely to occur, and a mold having a complicated structure can be formed without modifying the mold.

<Third embodiment>
Next, the mold manufacturing apparatus of 3rd embodiment is demonstrated using FIG.

  The mold manufacturing apparatus shown in FIG. 6 includes an upper jacket having two space portions 85 and 89. The jacket includes an upper body 82 in which a jacket communication passage 93 is formed, and a lower body 83 in which a partition wall 84, a through hole 91, and a cylindrical body 90, which will be described later, are formed. It is formed by integrally joining.

  The upper jacket shown in FIG. 6 has a recess formed so as to cover the external opening of the communication path 86 of the mold 3. The upper jacket has a partition that divides a space formed by the recess into an upper space 89 on the jacket communication path 93 side and a lower space 85 on the opening side of the recess, and a plurality of through holes formed in the partition 91 and a cylindrical body 90 projecting from the periphery of these through holes 91 toward the jacket communication path 93 side. The upper space part 89 and the lower space part 85 defined by the partition walls are communicated with each other through a through hole 91, and the lower space part 85 and the cavity 8 in the mold 3 are connected via a plurality of communication paths 86. It is connected. Further, the upper jacket has a drain hole 92 communicating with the upper space portion 89, and the drain hole 92 is formed at a position lower than the upper end of the cylindrical body 90. Further, the drain hole 92 is connected to the pipe via an on-off valve. The drain hole 92 is formed above the partition wall 84 of the jacket lower body 83.

  The jacket communication passage 93 communicates with the gas supply means, and the gas supplied from the gas supply means (gas supply device 6) is supplied to the upper space portion 89 via the jacket communication passage 93, and passes through the through hole 91. To the lower space. Thereafter, the gas supplied to the lower space is supplied to the cavity 8 in the mold 3 through the communication path 86.

  By using the mold manufacturing apparatus of the third embodiment, the water vapor supplied from the jacket communication passage 93 is supplied to the upper space part 89 and then sent to the lower space part through the through hole 91. The water vapor fed into the lower space is supplied to the cavity 8 in the mold 3 through each communication path 86. At this time, excess water droplets of the water vapor supplied into the upper space portion 89 are stored at the bottom of the upper space portion 89, and the stored water is discharged from the drain hole 92 to the outside. Thereby, it is possible to prevent water droplets from entering the cavity 8, and it is possible to prevent solidification and curing unevenness due to variations in the wet state of the coated sand 7.

<Fourth embodiment>
Next, the mold manufacturing apparatus of 4th embodiment is demonstrated using FIG.

  The mold manufacturing apparatus shown in FIG. 7 is different from the mold manufacturing apparatus of the first embodiment shown in FIG. 1 in the shape of the cavity of the mold 95 and the shape of the communication path, but the first side jacket and the second side. The same jacket can be used, and the gas can be supplied to the cavity 8 in the mold without providing a gas supply passage corresponding to the mold.

<Other embodiments>
Note that the present invention is not limited to the configuration of the above-described embodiment, and can be appropriately modified within the intended scope of the present invention.

  In the mold manufacturing apparatus, the mold 3 may be configured to be opened vertically and vertically. Further, the first side jacket 4 and the second side jacket 5 may be disposed on orthogonal surfaces that do not face each other depending on the configuration of the mold 3. The jacket communication passages 23 and 31 are not limited to the shape in which the inflow ports 22 and 30 and the outflow ports 21 and 29 are linearly connected, and the communication passages are formed in the first side jacket 4 or the second side jacket 5. It may be configured to have a plurality of outlets that branch off and serve as openings of the branched communication paths. Moreover, the shape which piping protruded from the outflow ports 21 and 29 in the space part may be sufficient, and the structure where this piping branched in the space part may be sufficient.

  The jacket communication passages 67 and 76 of the upper jacket 61 and the lower jacket 70 can be used not only as a flow path for supplying gas from the gas supply means but also as a flow path for discharging to the outside.

  Moreover, in order to make it easy to mix each gas, the mixing part 50 of a gas supply means may each attach a ventilation hole diagonally, and the blade | wing for mixing and a static mixer may be arrange | positioned inside the mixing part 50. . Furthermore, as a heat source of the preheater of the storage tank 51, a heater using a heater may be used. Moreover, it is preferable to preheat the mixing part 31 and the jacket 4, and it is connected to the mixing part 31 and the jacket 4 from the steam supply line 20 or the air supply line 18 after the heater 23 as a heat source for this preheating. Piping may be provided.

  Further, the upper surface communication path 9 may be an exhaust flow path and the lower surface communication path may be a supply flow path, or a jacket may be provided so that the supply flow path or the exhaust flow path can be selected. In this case, more patterns can be appropriately selected from the water vapor supply and exhaust patterns shown in FIG.

  In the mold manufacturing method, in the water vapor supply step, water vapor can be supplied from the upper surface communication path 9, the first side surface communication path 11, and the second side surface communication path 12, and the water vapor can be discharged from the lower surface communication path 10. . Further, water vapor can be supplied from the upper surface communication passage 9 and discharged from the first side surface communication passage 11, the second side surface communication passage 12 and the lower surface communication passage 10. The supply and exhaust of water vapor can be selected efficiently and in a short time depending on the shape of the cavity and the like.

  As described above, the mold manufacturing apparatus of the present invention is suitably used for manufacturing various molds such as molds used for manufacturing automobile parts.

DESCRIPTION OF SYMBOLS 1 Fixed type | mold 2 Movable type | mold 3 Mold | die 4 1st side part jacket 5 2nd side part jacket 6 Gas supply apparatus 7 Coated sand 8 Cavity 9 Upper surface communication path 10 Lower surface communication path 11 First side surface communication path 12 Second side surface communication path 13 Net 14 Pipe 15 Open / close valve 16 Open / close valve 17 Recess 18 Space 19 Recess 20 Space 21 Outlet 22 Inlet 23 Jacket communication passage 24 Pipe 25 Open / close valve 26 Discharge port 27 Discharge path 28 Open / close valve 29 Outlet 30 Inlet 31 Jacket communication passage 32 Piping 33 On-off valve 34 Opening 35 Exhaust path 36 On-off valve 37 Air supply line 38 Carbon dioxide supply line 39 Water vapor supply line 40 Flow meter 41 Pressure reducing valve 42 Heater 43 Flow meter 44 Pressure reducing valve 45 Flow meter 46 Pressure reducing valve 47 On-off valve 48 On-off valve 49 On-off valve 50 Mixing part 51 Reservoir 52 Discharge port 53 Air outlet hole 54 Flow Gas branch pipe 55 Heat exchanger 56 Straight pipe part 57 Annular pipe part 58 Pipe 59 Pipe 61 Upper jacket 62 Recess 63 Space part 64 Upper surface communication path 66 Inlet 67 Jacket communication path 68 Pipe 69 On-off valve 70 Lower jacket 71 Recess 72 Space Part 73 Lower surface communication path 75 Discharge path 76 Jacket communication path 77 On-off valve 78 Pipe 79 Suction machine 82 Upper body 83 Lower body 84 Partition 85 Lower space part 86 Communication path 89 Upper space part 90 Cylindrical body 91 Through hole 92 Drain hole 93 Jacket communication passage 95 Mold

Claims (32)

A mold having a cavity capable of being filled with coated sand;
A mold manufacturing apparatus comprising gas supply means for supplying gas to the cavity,
The mold has a top surface, a bottom surface, a first side surface, a second side surface, and a top surface, a bottom surface, a first side surface, and a second side surface, which communicate with the cavity.
At least any two of the upper surface communication path, the lower surface communication path, the first side surface communication path, and the second side surface communication path are connected to the gas supply means so that the communication state can be changed, and at least one type of communication path is provided. The mold manufacturing apparatus, wherein the passage has a function of exhausting the gas in the cavity.   The mold manufacturing apparatus according to claim 1, wherein the gas supply unit includes an on-off valve for changing a communication state with the communication path.   At least one of the communication passages to which the gas supply means is connected can be in communication with the outside air in a non-communication state with the gas supply means, and with the outside air in a communication state with the gas supply means. The mold manufacturing apparatus according to claim 1, wherein the mold manufacturing apparatus is provided so as to be in a non-communication state.   The mold manufacturing apparatus according to claim 1, wherein the first side surface and the second side surface are opposed to each other. The upper surface communication path, the first side surface communication path, and the second side surface communication path are connected so that the communication state with the gas supply means can be changed,
The lower surface communication path, the first side surface communication path and the second side surface communication path are provided so that the communication state with the outside air can be changed,
The first side surface communication path and the second side surface communication path can be in communication with the outside air in a non-communication state with the gas supply means, and are in a non-communication state with outside air in the communication state with the gas supply means. The mold manufacturing apparatus according to any one of claims 1 to 4, wherein the mold manufacturing apparatus is provided so as to be able to perform.   The recess has an opening on the abutting surface side and a jacket communication path capable of supplying gas from the gas supply means to the recess, and the recess has one external opening of the first side surface communication path or the second side surface communication path. The mold manufacturing apparatus according to any one of claims 1 to 5, further comprising a side jacket configured to be attachable to the mold so as to cover. A plurality of first side surface communication paths or second side surface communication paths are formed on the first side surface or the second side surface of the mold,
The mold manufacturing apparatus according to claim 6, wherein the recess is formed so as to cover the plurality of first side surface communication paths or second side surface communication paths. The side jacket further has a discharge path capable of discharging the gas in the recess,
The mold manufacturing apparatus according to claim 6 or 7, wherein the discharge path is provided so as to be openable and closable.   The mold manufacturing apparatus according to claim 8, further comprising suction means for sucking gas from the discharge path.   The mold manufacturing apparatus according to any one of claims 6 to 9, wherein the pair of side jackets are mounted on the mold so as to face each other, and the pair of side jackets have the same shape.   The recess has an opening on the contact surface side and a jacket communication path capable of supplying gas from the gas supply means to the recess, and the recess is configured to be attachable to the mold so as to cover the external opening of the upper surface communication path. The mold manufacturing apparatus according to any one of claims 1 to 10, further comprising an upper jacket. A plurality of upper communication passages are formed on the upper surface of the mold,
The mold manufacturing apparatus according to claim 11, wherein the recess is formed so as to cover the plurality of upper communication paths.   The upper jacket protrudes from the periphery of the through hole to the jacket communication path side, partitioning the space formed by the recess into the jacket communication path side and the recess opening side, the through hole formed in the partition wall The mold manufacturing apparatus of Claim 11 or Claim 12 which has a cylindrical body made.   The gas supply means includes a branch portion branched upstream from a connection portion with the upper jacket, and an on-off valve that controls gas supply to the recess of the upper jacket downstream from the branch portion. The mold manufacturing apparatus according to claim 11, claim 12 or claim 13.   The mold manufacturing apparatus according to any one of claims 11 to 14, wherein the upper jacket is provided so that the gas in the recess can be discharged.   The mold manufacturing apparatus according to claim 15, further comprising suction means for sucking the gas in the recess.   The recess has an opening on the contact surface side and a jacket communication path capable of supplying gas from the gas supply means to the recess, and the recess is configured to be attachable to the mold so as to cover the external opening of the lower surface communication path. The mold manufacturing apparatus according to any one of claims 1 to 16, further comprising a lower jacket. A plurality of lower communication passages are formed on the lower surface of the mold,
The mold manufacturing apparatus according to claim 17, wherein the recess is formed to cover the plurality of upper communication paths.   The gas supply means has a branching portion branched upstream from a connection portion with the lower jacket, and an on-off valve for controlling gas supply to the concave portion of the lower jacket downstream from the branching portion. The mold manufacturing apparatus according to claim 17 or 18.   20. The mold manufacturing apparatus according to claim 17, 18 or 19, wherein the lower jacket is provided so that the gas in the recess can be discharged.   The mold manufacturing apparatus according to claim 20, further comprising suction means for sucking the gas in the recess. The gas supply means includes an air supply line, a water vapor supply line, a carbon dioxide supply line, and an opening / closing valve capable of switching and mixing these supply lines,
The mold manufacturing apparatus according to any one of claims 1 to 21, wherein a heater is provided in the air supply line.   The mold manufacturing apparatus according to claim 22, wherein a flow meter and a pressure reducing valve are provided in the air supply line, the water vapor supply line, and the carbon dioxide supply line.   2. The coated sand supply means includes a storage tank for supplying the coated sand to the cavity via a communication path, and a preheater disposed in the storage tank for preheating the coated sand. The mold manufacturing apparatus according to any one of claims 21 to 21. The gas supply means includes a water vapor supply line,
25. The mold manufacturing apparatus according to claim 24, wherein the preheater uses steam diverted from the steam supply line as a heat source.   The mold manufacturing apparatus according to claim 25, wherein the preheater has a spiral hollow tube through which the water vapor flows. The gas supply means includes an air supply line provided with a heater,
25. The mold manufacturing apparatus according to claim 24, wherein the preheater has an air ejection hole for ejecting air diverted from the air supply line after the heater. A step of filling the coated mold cavity of the mold manufacturing apparatus according to any one of claims 1 to 27 with coated sand,
A water vapor supply step of supplying water vapor to the coated sand of the cavity by a gas supply means;
A mold manufacturing method comprising: a drying step of drying the coated sand containing water vapor by the water vapor supply step.   29. The mold manufacturing method according to claim 28, wherein, in the water vapor supply step, water vapor is supplied from the upper surface communication passage, the first side surface communication passage, and the second side surface communication passage, and the water vapor is discharged from the lower surface communication passage.   29. The method for producing a mold according to claim 28, wherein in the first water vapor supply step, water vapor is supplied from the upper surface communication passage, and water vapor is discharged from the first side surface communication passage, the second side surface communication passage, and the lower surface communication passage.   The water-soluble binder for covering the refractory aggregate forming the coated sand is one or more of thermosetting resins, saccharides, proteins, synthetic polymers, salts, or inorganic polymers. A method for producing a mold according to claim 29 or claim 30.   The method for producing a mold according to claim 28, 29, or 30, wherein an alkali phenol resin is used as a water-soluble binder for covering the refractory aggregate forming the coated sand.

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