JP5510074B2 - Method and apparatus for removing water-soluble core - Google Patents

Description

  The present invention relates to a method of removing, for example, a core used for casting of an aluminum alloy, in particular, a water-soluble core after casting, and a removal device used for the method.

As a core used for casting an aluminum alloy, a water-soluble core that is dissolved in water after casting using a salt or the like has been developed. Conventionally, a technique of immersing and dissolving in water is known for removing this type of water-soluble core used for casting of aluminum alloy or the like (Patent Documents 1 and 2).
Similarly, a technique of immersing a water-soluble core in hot water or warm water to promote dissolution is also known (Patent Document 3 and Patent Document 4).

  In addition, this type of water-soluble core has been developed that uses high-pressure water (that discharges water, hot water, or a dedicated liquid at a high pressure) instead of being immersed in water, warm water, or a dedicated liquid. . The thing of patent document 5 is known as an example removed by high pressure water.

Japanese Patent Publication No.52-10803 JP 2005-297709 A JP 50-136225 A Japanese Patent Laid-Open No. 51-50218 JP 2008-36702 A

However, in the method of dissolving and removing the water-soluble core by immersing in water as described above, the core component (water-soluble component) is contained in the wastewater after dissolution, and the load on the wastewater treatment facility There were problems such as high.
Further, as disclosed in Patent Document 5, a method for removing a water-soluble core using high-pressure water is also effective, but the conditions for high-pressure water and the like are not particularly specified.

  In view of such circumstances, an object of the present invention is to provide a water-soluble core removal method and apparatus capable of effectively reducing wastewater treatment and environmental load.

The method for removing a water-soluble core according to the present invention is a method for removing a water-soluble core in a water-soluble core removal device that crushes and removes a water-soluble core from a cast product using a water jet. And the crushed pieces of the water-soluble core are separated from each other at the bottom of the cast product before being dropped onto the bottom of the water-soluble core removal device .
The water-soluble core removing method of the present invention further includes a step of immediately transferring the crushed pieces separated into solid and liquid to the outside of the water-soluble core removing device .

The water-soluble core removing device of the present invention is a water-soluble core removing device for crushing and removing a water-soluble core from a cast product using a water jet, and a water jet is disposed below the cast product. It is characterized by comprising separation and transfer means for carrying out solid-liquid separation between water and the crushed pieces of the water-soluble core and transferring the separated crushed pieces.
In the water-soluble core removal apparatus of the present invention, the separation and transfer means is constituted by a conveyor having a mesh structure.

  According to the present invention, when removing a water-soluble core from a cast product, the water-soluble core crushed by high-pressure water is immediately moved out of the drainage path without staying in the drainage path in the core removal device. Thus, the concentration or total dissolution amount of the core component contained in the wastewater can be greatly reduced, and the load on the wastewater treatment and the load on the environment such as the river can be effectively reduced.

It is a sectional side view which shows the example of the water-soluble core in the embodiment of this invention, and its casting. It is each sectional side view which shows the removal process of the water-soluble core of this invention in order. It is a figure which shows the structural example of the core removal apparatus which concerns on the water-soluble core of this invention. It is a figure which shows the modification of the core removal apparatus which concerns on the water-soluble core of this invention. It is a figure which shows another modification of the core removal apparatus which concerns on the water-soluble core of this invention.

Hereinafter, preferred embodiments of a water-soluble core removal method and apparatus according to the present invention will be described with reference to the drawings.
In the present invention, a cast product is cast using a water-soluble core, and the water-soluble core cast into the cast product is removed after the casting. In the step of removing the water-soluble core after casting, the water-soluble core is not completely dissolved from the cast product (aluminum alloy) but is dissolved or ground using high-pressure water.

  In the present invention, when removing the water-soluble core from the casting, the water-soluble core crushed by the high-pressure water is immediately moved out of the drainage path without being kept in the drainage path in the core removal device, This is to reduce the concentration or total dissolution amount of core components contained in the wastewater. The method and apparatus for removing the water-soluble core will be described below. The process of drying the removed core pulverized product and the reuse of the removed core pulverized product will be described. In addition, if it is a casting which uses a water-soluble core, it can utilize also in castings, such as an aluminum alloy, a zinc alloy, and a magnesium alloy.

In the present invention, the water-soluble core is preferably pulverized so as not to be completely dissolved, and this is performed with high-pressure water, thereby promoting the pulverization.
In this embodiment, the water-soluble core is prepared by using a mixed salt of NaCl and KCl as a basic component and adding ceramic particles as a reinforcing component. Using this water-soluble core, aluminum die casting was performed, and the core was removed using high-pressure water. Details are shown below.

  First, the production of the water-soluble core in this embodiment will be described. As a water-soluble core, a 50:50 mixed salt of NaCl: KCl in mol% as a solute is heated and melted at 750 ° C. 20 vol% of ceramic particles are mixed with this and poured into a core manufacturing mold to form a core. In the present embodiment, for example, a cylinder head of a single cylinder engine, in particular, its intake and exhaust ports are cast using a water-soluble core.

  Next, aluminum die casting is performed using the water-soluble core produced as described above. In this case, the water-soluble core is held at a predetermined position in the cylinder head mold for high pressure die casting, and the molten material (ADC12 aluminum alloy) is subjected to predetermined conditions (injection casting pressure 58 MPa, injection speed 3.0 m / sec). ) Was cast into a cylinder head shape. FIG. 1 shows an example of a cylinder head 1 as a cast product cast using a water-soluble core 10 in this embodiment. For example, as in this example, the cylinder head 1 has an intake port 3 and an exhaust port 4 on both sides of the combustion chamber 2. As indicated by the oblique lines, the water-soluble cores 10 (10A, 10B) are disposed at the corresponding portions of the intake port 3 and the exhaust port 4.

  Aluminum die casting is performed using the water-soluble core 10 as described above, and the cylinder head 1 is cast as shown in FIG. The water-soluble core 10 is removed after casting. In this case, the water-soluble core 10 is taken out by pressure jetting using room temperature industrial water. The core removing device described later has a high-pressure water nozzle 201 as shown in FIGS. 2B and 2C, and the high-pressure water is directed from the high-pressure water nozzle 201 toward the cylinder head 1 (the water-soluble core 10). w (water jet) is injected.

  In the above case, the nozzle diameter of the high-pressure water nozzle 201 was fixed at 1.6 mm, the applied pressure was set to 5, 10, 20, 30, 40, and 50 MPa, and the pulverization rate of the water-soluble core 10 was determined for each. . The distance between the water-soluble core 10 and the high-pressure water nozzle 201 was L = 100 mm, and the high-pressure water injection time was 90 seconds. In addition, the grinding | pulverization rate of the water-soluble core 10 shows the ratio of the undissolved part contained in the waste_water | drain after core removal with respect to the core weight before melt | dissolution. Moreover, the state of the site | part which the high-pressure water directly contacted the aluminum casting was observed, and the damage state of the aluminum casting was judged. Table 1 shows the results of the core removal experiment.

From these experimental results, it was confirmed that the high-pressure water pressure is preferably 10 MPa or more and 40 MPa or less in order to pulverize and remove the water-soluble core 10 efficiently. If it is the pressure of this range, it is possible to grind | pulverize a core simultaneously with melt | dissolution by the effect of water pressure.
On the other hand, when the high-pressure water pressure is less than 10 MPa, the water-soluble core 10 can be removed, but the pulverization rate is deteriorated, and it has been confirmed that most of the water-soluble core 10 is dissolved as it is. Moreover, damage to the aluminum casting is observed at 45 MPa or more. Therefore, it was confirmed that 20 to 40 MPa was optimal for removing the water-soluble core 10.

  Next, a method for taking out the crushed core (undissolved part) will be described. The present invention includes a method of moving the pulverized core contained in the waste water after the high-pressure water injection to the outside of the core removing device without accumulating in the drain tank or touching the water. . In that case, it is desirable that the device for moving the pulverized material is provided in the core removing device or provided together. As the moving device, a mesh ground conveyor or the like is suitable, and in the case of a core containing a component that corrodes a metal such as salt, it is preferable to use a stainless steel or resin material.

  Here, in general, in an apparatus for removing a water-soluble core using high-pressure water or the like, a filter such as a metal mesh or non-woven fabric is provided in the drainage channel at the top or inside of the drainage tank or in front of the drainage tank, and the core is crushed. And solids spill prevention measures are used. However, in this case, since the pulverized core is always in contact with water (drainage), it is considered that dissolution of the pulverized product of the water-soluble core removed from the casting proceeds easily. Therefore, in the present invention, the pulverized water-soluble core contained in the waste water after the high-pressure water injection is not stored in the drain tank or the drain passage or is not exposed to the water. Moved to immediately. Thereby, it is possible to prevent further pulverization of the water-soluble core removed from the cast product, and to reduce the water-soluble core component contained in the waste water (reduction of the total dissolution amount). . As a result, it is possible to reduce the wastewater treatment load and the environmental load on the river that is the discharge destination.

  FIG. 3 shows a configuration example of the core removing device 200 according to the present invention. In the core removing device 200, device constituent members are housed in a casing 202 having a basically sealed structure. In this example, the cylinder head 1 which is a workpiece is held at a predetermined position in the housing 200, and a high-pressure water nozzle 201 is disposed corresponding to the water-soluble core 10 to be removed. As described above, the high-pressure water w is jetted from the high-pressure water nozzle 201 toward the water-soluble core 10. Below the cylinder head 1 is disposed a chute 203 that is preferably inclined as shown in the figure. In this case, the crushed material 10a of the water-soluble core 10 detached from the cylinder head 1 and water and solution (water jet water) injected as high-pressure water w (water jet) fall on the chute 203, and these The crushed material 10a and the water jet water naturally move to the discharge port 204 along the chute 203, and are further dropped or thrown from the discharge port 204 to a transfer device described later.

  In this example, a belt conveyor system is adopted as a transfer device for the pulverized material 10a of the water-soluble core 10 removed from the cast product. In FIG. 3, a conveyor 206 constituting the transfer device 205 is laid below the discharge port 204. One or a plurality of conveyors 206 (206A, 206B) may be used as in the illustrated example, and the crushed material 10a is transferred as indicated by an arrow, and finally the end of the conveyor 206 is outside the core removing device 200. It is set as the structure extended to. A collection unit or collection container 207 is disposed below the end of the conveyor 206 (206B), and the crushed material 10a is dropped from the conveyor 206 into the collection container 207.

  On the other hand, a drainage storage unit 208 (pool) is provided at the bottom of the core removing device 200, and the solution w ′ containing the core component is temporarily stored in the drainage storage unit 208. As shown in the figure, the solution w ′ in the drainage reservoir 208 is discharged from the drain 210 to the drainage tank 211 via the strainer 209 at the bottom, and sent to a predetermined department (such as a processing facility).

  In this transfer device 205, a belt conveyor is used as means for separating the “solution containing the core component” and the “undissolved pulverized product” discharged when dissolved and pulverized with high-pressure water. In order to perform separation efficiently, the belt conveyor is preferably a mesh, and in the case of a core containing a component that corrodes a metal such as salt, it is preferable to use a belt made of a stainless material or a resin material. . Of the “solution containing the core component” and the “undissolved pulverized product” dropped on the transfer device 205, the solution passes through the conveyor 206 and falls as it is, and the pulverized product is transferred on the conveyor 206.

  Here, as a method of immediately separating the “solution containing the core component” and the “undissolved pulverized product” discharged when dissolved and pulverized with high-pressure water, in addition to the above-described belt conveyor method, For example, the same effect can be obtained by using a rotating drum type, centrifugal separation, or the like. FIG. 4 shows another configuration example of the transfer device 205. In this example, the transfer device 205 is constituted by a rotating drum 212. In this case, the rotary drum 212 is made of a mesh base material, and the “solution containing the core component” and the “undissolved pulverized product” dropped from the discharge port 204 are put into the rotary drum 212. The rotating drum 212 filters and discharges the separated solution while rotating, and transfers the pulverized material 10 a to the collection container 207.

  In the above case, the moving device 205 for the pulverized product 10a of the water-soluble core 10 is desirably provided in the core removing device 200 or in the core removing device 200. Such an arrangement makes it possible to improve work efficiency and simplify the layout, thereby realizing cost reduction.

  Further, a method for drying the undissolved core taken out, its apparatus configuration, and reuse will be described. Regarding the treatment of the undissolved core pulverized product taken out of the core removal device, it can be discarded or reused. It is desirable to dry in advance for disposal or reuse. In the present invention, by adding a drying device in the vicinity of the core removing device, a series of steps from removing the core to collecting undissolved material and drying can be performed by a consistent system.

  FIG. 5 shows a system configuration example including a drying device. When discarding the undissolved core pulverized product, it is difficult to dispose of the crushed material in the state of containing moisture, so it is necessary to dry it. Further, even in the case of reuse, it is necessary to dry it because it will hinder reuse in a state containing moisture. That is, if the core pulverized product recovered in the step of taking out the water-soluble core can be dried on the spot, there is no need to newly dry it in the subsequent step.

  As shown in FIG. 5, a drying device 213 is attached in the vicinity of the extended portion of the transfer device 205 so that the process from the core removal to recovery and drying is performed by a consistent system. The drying device 213 may include, for example, a tunnel-type drying furnace 214 and a heater unit 215 disposed in the drying furnace 214, and the pulverized material 10a transferred by the transfer device 205 can be dried in a short time. Such systemization makes it possible to improve work efficiency and simplify the layout, thereby reducing costs.

In FIG. 5, the example of the tunnel-type drying furnace 214 having the heater unit 215 as the drying device 213 has been described. However, the same effect can be obtained by, for example, hot air drying.
Note that the drying device 213 can be installed inside the core removing device 200 as long as conditions or problems such as waterproofness and installation space are satisfied.

As mentioned above, although this invention was demonstrated with various embodiment, this invention is not limited only to these embodiment, A change etc. are possible within the scope of the present invention.
For example, although an example of a cylinder head has been described as an application target of the present invention, the present invention can be effectively applied to this type of casting in substantially the same manner as in the above-described embodiment.
Further, as a means for separating the “solution containing the core component” and the “undissolved pulverized product” introduced from the discharge port 204 and transferring the pulverized product, other than the above case, for example, in the form of a slide By laying a transfer path made of an inclined mesh material and appropriately vibrating the transfer path, a separation transfer means can be configured.

DESCRIPTION OF SYMBOLS 1 Cylinder head, 2 Combustion chamber, 3 Intake port, 4 Exhaust port, 10 Water-soluble core, 10a Ground material, 200 Core removal apparatus, 201 High pressure water nozzle, 202 Case, 203 Chute, 204 Outlet, 205 Transfer Apparatus, 206 Conveyor, 207 Collection container, 208 Drainage storage unit, 209 Strainer, 210 Drain, 211 Drain tank, 212 Rotating drum, 213 Drying device, 214 Drying furnace, 215 Heater unit.

Claims (4)

A method for removing a water-soluble core in a water-soluble core removal device that crushes and removes a water-soluble core from a casting using a water jet,
Before the water jet water and the crushed pieces of the water-soluble core are dropped to the bottom of the water-soluble core removal device, they have a step of solid-liquid separation below the casting. To remove the water-soluble core. Method for removing the water soluble core of claim 1, further comprising the step of transferring to the device outside of immediately the water soluble core removal device solid-liquid separated fragments. A water-soluble core removing device for crushing and removing a water-soluble core from a casting using a water jet,
The water-soluble medium is provided with separation and transport means for separating the water jet water and the crushed pieces of the water-soluble core from each other in a solid-liquid manner and transferring the separated crushed pieces below the cast product. Child removal device.   4. The water-soluble core removing device according to claim 3, wherein the separating and transferring means is constituted by a conveyor having a mesh structure.

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