JP7247856B2 - FOAMED SAND MANUFACTURING METHOD AND FOAMED SAND MANUFACTURING DEVICE - Google Patents

Description

TECHNICAL FIELD The present invention relates to a foam sand manufacturing method and a foam sand manufacturing apparatus.

A core is used to form a hollow inside the cast part. The core is manufactured by filling foamed sand, which is a raw material, into a mold and molding it.

Patent Document 1 discloses a method for producing foamed sand by kneading sand, water glass, water, and a surfactant to produce foamed sand.

JP 2017-87247 A

Sand, water glass, water, and surfactants are used as raw materials to produce foamed sand. As the sand, reclaimed sand produced by reusing cores can be used.

However, since water glass remains in the reclaimed sand, the water glass is eluted from the reclaimed sand during production. For this reason, even if a predetermined amount of raw material is put in the production of foamed sand, the amount of water glass eluted from the reclaimed sand becomes excessive, making it difficult to produce foamed sand properly. I had a problem that I couldn't.

SUMMARY OF THE INVENTION In view of the above problems, an object of the present invention is to provide a method for producing foamed sand and an apparatus for producing foamed sand, which can appropriately produce foamed sand even when reclaimed sand is used.

A method for producing foamed sand according to an aspect of the present invention comprises leaving kneaded foamed sand for a predetermined period of time, and then adding sand, water glass, water, and a surfactant to the foamed sand after the standing. a method for producing foamed sand by kneading the foamed sand by kneading the foamed sand with the foamed sand, wherein the amount of water glass added to the foamed sand after standing is determined based on the amount of the newly added sand. The amount is obtained by subtracting the amount of water glass eluted from the reclaimed sand contained in the foamed sand left for the predetermined period from the specified amount.

An apparatus for producing foamed sand according to an aspect of the present invention includes a storage unit capable of storing raw materials including sand, water glass, water, and a surfactant, a raw material charging unit for charging the raw materials into the storage unit, and A kneading unit for kneading the raw material stored in the storage unit, and an input amount calculation unit for calculating the amount of the raw material to be input from the raw material input unit to the storage unit. Then, after the foamed sand produced by kneading is left for a predetermined period in the storage part, sand, water glass, water, and surfactant are newly added from the raw material charging part to the foamed sand after the standing. , when producing foamed sand by kneading in the kneading unit, the input amount calculation unit calculates the amount of foamed sand left for the predetermined period from a specified amount determined based on the amount of newly added sand. The amount of water glass eluted from the reclaimed sand contained in the foamed sand is subtracted to calculate the amount of water glass put into the foamed sand after standing.

In the present invention described above, when new raw materials are added to the foamed sand after standing to manufacture the foamed sand, the amount of water glass added to the foamed sand after standing is adjusted to the amount of newly added sand. The amount is the amount obtained by subtracting the amount of water glass eluted from the reclaimed sand contained in the foamed sand left for a predetermined period from the specified amount determined based on the above. That is, in the present invention, the amount of newly added water glass is calculated in consideration of the amount of water glass eluted from the reclaimed sand, so the amount of water glass to be added should be an appropriate amount. can be done. Therefore, foamed sand can be produced appropriately.

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide a method for producing foamed sand and an apparatus for producing foamed sand, which are capable of appropriately producing foamed sand even when recycled sand is used.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure for demonstrating the foaming sand manufacturing apparatus concerning embodiment. It is a figure for demonstrating the manufacturing method of foamed sand concerning embodiment. It is a block diagram which shows the concrete structure of an input amount calculation part. It is a graph which shows the relationship between the standing time of foamed sand, and the amount of elution of water glass.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a diagram for explaining a foamed sand manufacturing apparatus according to this embodiment. As shown in FIG. 1 , the foamed sand manufacturing apparatus 1 includes a storage section 10 , an input amount calculation section 15 , a raw material input section 16 and a kneading section 17 .

In the foamed sand manufacturing apparatus 1 according to the present embodiment, a discharge port 11 for discharging the foamed sand 12 is formed at the bottom of the container 10 . That is, the foamed sand manufacturing apparatus 1 according to the present embodiment is configured to discharge the foamed sand 12 from the discharge port 11 and fill the mold 21 (see FIG. 2) with the foamed sand. Note that the configuration shown in FIG. 1 is an example, and the foamed sand manufacturing apparatus according to the present embodiment may be configured without the discharge port 11 at the bottom of the storage section 10 . In other words, the foamed sand manufacturing device and the foamed sand filling device may be provided separately.

The storage part 10 shown in FIG. 1 is configured to be able to store the raw material of the foamed sand 12 . The housing part 10 is, for example, a structure having a cavity inside, and can be configured using a metal material such as stainless steel. In addition, in the present embodiment, the storage part 10 also functions as a cylinder when filling the mold 21 with foamed sand 12 . That is, as shown in the filling step of FIG. Cavity 22 is filled with foam sand 24 .

Raw materials of foamed sand 12 include sand, water glass, water, and surfactants.

The sand includes recycled sand. Reclaimed sand is produced (reclaimed) from foundry cores containing water glass. As the reclaimed sand (sand), natural sand such as silica sand or zircon sand, or artificial sand containing mullite, corundum, or the like as a main component can be used.

Water glass (Na ₂ O.nSiO ₂ .mH ₂ O) is a mixture containing silicon dioxide (SiO ₂ ), sodium oxide (Na ₂ O) and water (H ₂ O). The ratio (molar ratio) of these materials constituting the water glass is not particularly limited as long as the foamed sand 12 can be formed.

An anionic surfactant, for example, can be used as the surfactant. For example, it is preferable to use a sulfate-based anionic surfactant. These surfactants are merely examples, and the type of surfactant is not particularly limited as long as the foamed sand 12 can be formed.

The input amount calculation unit 15 shown in FIG. 1 calculates the amount of raw material to be input into the storage unit 10 . The input amount calculation unit 15 can be configured using a calculation means. For example, the input amount calculator 15 may be included in a controller (not shown) that controls the foamed sand manufacturing apparatus 1 . The details of the input amount calculation unit 15 will be described later.

The raw material charging unit 16 charges raw materials for the foamed sand 12 into the storage unit 10 . Specifically, the raw material charging unit 16 charges raw materials 50 corresponding to the charging amounts of sand (recycled sand), water glass, water, and surfactant calculated by the charging amount calculation unit 15 into the storage unit 10. do. For example, the raw material input section 16 may include means for weighing each raw material 50 .

The kneading section 17 kneads the raw materials stored in the storage section 10 . The kneading unit 17 includes a stirrer 18 and a shaft 19, and the stirrer 18 rotates as the shaft 19 rotates. As a result, the stirrer 18 rotates in the container 10 to knead the raw material. The kneading section 17 is controlled using a control section (not shown). Although FIG. 1 shows the case where the stirrer 18 of the kneading section 17 is formed of a mesh-like structure, the shape of the kneading section 17 may be any other shape in the present embodiment.

Next, a method for manufacturing foamed sand according to the present embodiment will be described. FIG. 2 is a diagram for explaining the method of manufacturing foamed sand according to the present embodiment, and is a diagram for explaining the entire core manufacturing process. In the manufacturing process shown in FIG. 2, a filling process (S1), a raw material input process (S2), and a kneading process (S3) are shown. The production of foamed sand and the production of the core can be repeatedly carried out.

First, sand, water glass, water, and a surfactant, which are raw materials for the foamed sand 12, are put into the container 10, and these raw materials are kneaded using the kneading unit 17 to manufacture the foamed sand 12 in advance.

After that, as shown in the filling step (S1) in FIG. are connected to each other. Then, the piston 13 is arranged inside the housing portion 10, and the piston driving device 14 is used to move the piston 13 downward. As a result, the foamed sand 12 inside the container 10 is discharged from the outlet 11 at the bottom of the container 10 , and the cavity 22 of the mold 21 is filled with the foamed sand 24 . The foam sand filled in the cavity 22 of the mold 21 is indicated by 24 .

The mold 21 filled with foamed sand 24 is then subjected to a heating process and the like to manufacture a core. As for the core manufacturing process, since a general manufacturing process can be used, detailed description thereof is omitted.

Next, the housing portion 10 is separated from the mold 21 . Then, as shown in the raw material charging step (S2) in FIG. 2, new raw materials 50 (that is, sand, water glass, water, and surfactant) are added to the foamed sand 12 remaining in the container 10. . The amounts of these raw materials 50 to be put into the container 10 are calculated by the put-in amount calculator 15 . The raw material charging unit 16 charges the amount of the raw material 50 calculated by the charging amount calculating unit 15 into the storage unit 10 . For example, in the storage unit 10, the same amount of foamed sand 12 as the foamed sand 24 filled in the mold 21 (the total amount of foamed sand when the mold 21 is filled with foamed sand multiple times) is manufactured. The amount of raw material 50 required to do so is newly introduced.

After that, as shown in the kneading step (S3) in FIG. Then, the foamed sand 12 is produced by rotating the kneading unit 17 (stirring element 18) to knead the raw materials.

After that, in the filling step ( S<b>1 ), the housing part 10 is placed on the mold 21 again, and the foaming sand 24 is filled into the cavity 22 of the mold 21 . By repeating such steps (S1 to S3), it is possible to repeatedly perform the production of foamed sand, which is the raw material of the core, and the production of the core.

Here, when the series of steps (S1 to S3) shown in FIG. 2 are to be stopped for a long time, the facility is stopped immediately before the raw material charging step (S2). However, since recycled sand is used as a raw material for the remaining foamed sand 12, and water glass remains in the recycled sand, if the facility is stopped immediately before the raw material input step (S2), , water glass may be eluted from the reclaimed sand contained in the remaining foamed sand 12 . That is, although water glass remains in the reclaimed sand, among the remaining water glass, the water glass eluted from the reclaimed sand newly functions as water glass.

Therefore, even if the operation of the facility is restarted and a predetermined amount of raw material is added in the raw material charging step (S2), the amount of water glass eluted from the reclaimed sand becomes excessive, resulting in an excessive amount of water glass. There was a problem that foamed sand could not be manufactured.

Specifically, when the amount of water glass is excessive, the pH value of the foaming sand increases, which reduces the foaming ability of the surfactant. When the foaming ability of the surfactant is reduced in this way, the porosity in the foamed sand is reduced, and as a result, the kinematic viscosity of the foamed sand to be produced deviates from the predetermined target value, and the mold for the foamed sand is affected. However, there is a problem that the filling property of is deteriorated.

In order to solve such a problem, in the present embodiment, after the kneaded foamed sand is left in the container 10 for a predetermined period of time, the operation of the equipment is restarted, and the material is added in the material input step (S2). When doing so, do the following: That is, the amount of water glass to be added to the foamed sand after standing is changed from the specified amount determined based on the amount of sand to be newly added to the amount of foamed sand left for a predetermined period (remaining foamed sand). The amount is obtained by subtracting the amount of water glass eluted from the recycled sand contained in the sand.

That is, the input amount calculation unit 15 calculates the amount of water glass contained in the foamed sand left for a predetermined period (residual foamed sand) from the specified amount (b) of water glass determined based on the amount of newly input sand. By subtracting the amount (a) of water glass eluted from the reclaimed sand, the amount (ba) of water glass put into the foamed sand after standing is calculated.

Therefore, the amount of water glass introduced when the operation of the facility is resumed (that is, the amount of water glass introduced in the raw material introduction step (S2)) can be set to an appropriate amount. can be manufactured to

Moreover, since it is possible to prevent the amount of water glass from becoming excessive, it is possible to prevent the kinematic viscosity of the produced foamed sand from deviating from the predetermined target value. Therefore, it is possible to improve the fillability of the foamed sand into the mold.

For example, the amount of water glass eluted from reclaimed sand may be calculated using data (graph) obtained experimentally in advance. Specifically, as shown in FIG. 4, the amount of elution of water glass with respect to the standing time of foamed sand is experimentally obtained in advance. Here, "amount of water glass eluted" may be "amount of water glass eluted from foamed sand per unit volume", or "eluted amount of water glass eluted from foamed sand per unit weight". It may be "amount".

Also, the time (predetermined period) during which the foamed sand is left is measured. Also, the amount of reclaimed sand contained in the foamed sand that has been left is obtained in advance. Then, the amount of water glass eluted from the recycled sand is calculated by using the data (graph) shown in FIG. 4, the standing time of the foamed sand, and the amount of recycled sand contained in the left foamed sand. can be done.

The amount of water glass eluted from the reclaimed sand may be calculated by the input amount calculator 15 . FIG. 3 is a block diagram showing a specific configuration of the input amount calculator 15. As shown in FIG. As shown in FIG. 3, the input amount calculation unit 15 includes a sand input amount calculation unit 31, a water glass input amount calculation unit 32, a water input amount calculation unit 33, a surfactant input amount calculation unit 34, and a standing time calculation unit 35. , and a water glass elution amount calculator 36 .

The sand input amount calculator 31 calculates the amount of sand to be newly input in the raw material input step (S2) shown in FIG. For example, the sand input amount calculation unit 31 calculates the same amount of foaming sand 24 that was filled in the mold 21 in the previous process (the total amount of foaming sand when the mold 21 is filled with foaming sand multiple times). The amount of sand required to produce foamed sand 12 is calculated.

The left time calculation unit 35 calculates the time during which the foamed sand 12 remaining in the storage unit 10 has been left. For example, the standing time calculation unit 35 can calculate (measure) the standing time of the foamed sand 12 using a timer.

The water glass elution amount calculator 36 calculates the amount of water glass eluted from the recycled sand contained in the foamed sand left for a predetermined period. For example, the water glass elution amount calculator 36 stores data (see FIG. 4) regarding the amount of water glass elution with respect to the amount of time the foamed sand is allowed to stand, which is obtained experimentally in advance. Then, the water glass elution amount calculation unit 36 calculates the data on the amount of water glass elution with respect to the standing time of the foamed sand, the standing time of the foamed sand 12 calculated by the standing time calculating unit 35, and the The amount (a) of water glass eluted from the reclaimed sand can be calculated by using the amount of reclaimed sand to be dissolved and the amount of reclaimed sand.

The water glass input amount calculation unit 32 calculates a specified amount (b) of water glass based on the amount of newly input sand calculated by the sand input amount calculation unit 31 . Then, the water glass input amount calculation unit 32 subtracts the water glass elution amount (a) calculated by the water glass elution amount calculation unit 36 from the calculated specified amount (b) of water glass, and obtains the water glass input amount. (ba) is calculated.

The water input amount calculation unit 33 calculates the input amount of water based on the amount of newly input sand calculated by the sand input amount calculation unit 31 . The surfactant input amount calculator 34 calculates the input amount of surfactant based on the amount of newly input sand calculated by the sand input amount calculator 31 .

Sand input amount calculated by sand input amount calculation unit 31, water glass input amount calculated by water glass input amount calculation unit 32, water input amount calculated by water input amount calculation unit 33, and surfactant input amount Each piece of information on the surfactant input amount calculated by the calculation unit 34 is supplied to the raw material input unit 16 . The raw material charging unit 16 charges sand (recycled sand), water glass, water, and surfactant in amounts corresponding to the respective charging amounts into the storage unit 10 .

The configuration of the input amount calculation unit 15 shown in FIG. 3 is an example, and in the present embodiment, the configuration of the input amount calculation unit 15 may be a configuration other than this.

As described above, the present invention has been described in accordance with the above embodiments, but the present invention is not limited only to the configurations of the above embodiments, and is applicable within the scope of the invention of the claims of the present application. Needless to say, it includes various modifications, modifications, and combinations that can be made by a trader.

1 foamed sand manufacturing apparatus 10 container 11 discharge port 12 foamed sand 13 piston 14 piston driving device 15 input amount calculation unit 16 raw material input unit 17 kneading unit 18 stirrer 19 shaft 21 mold 22 cavity 23 input port 24 foamed sand 31 Sand input amount calculation unit 32 Water glass input amount calculation unit 33 Water input amount calculation unit 34 Surfactant input amount calculation unit 35 Leaving time calculation unit 36 Water glass elution amount calculation unit 50 Raw materials

Claims (2)

Manufacture of foamed sand by leaving kneaded foamed sand for a predetermined period and then adding sand, water glass, water, and a surfactant to the left foamed sand and kneading the foamed sand. a method,
The amount of water glass added to the foamed sand after standing is eluted from the recycled sand contained in the foamed sand left for the predetermined period from the specified amount determined based on the amount of the newly added sand. is characterized by being the amount less the amount of water glass used,
A method for producing foamed sand. a container capable of containing raw materials including sand, water glass, water, and a surfactant;
a raw material input unit for inputting the raw material into the storage unit;
a kneading unit that kneads the raw material accommodated in the accommodating unit;
an input amount calculation unit that calculates the amount of raw material to be input from the raw material input unit to the storage unit,
After the foamed sand produced by kneading is left in the container for a predetermined period of time, sand, water glass, water, and a surfactant are newly added from the raw material charging part to the foamed sand after the standing, and the When the foamed sand is manufactured by kneading in the kneading unit, the input amount calculation unit determines the amount of sand contained in the foamed sand left for the predetermined period from the specified amount determined based on the amount of the newly added sand. The amount of water glass eluted from the reclaimed sand is subtracted to calculate the amount of water glass added to the foamed sand after standing.
Foam sand production equipment.

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