JPWO2011013730A1 - Casting unit and casting method - Google Patents

Abstract

A non-extinguishable runner is connected to an extinguishable sprue mounted on the core, and the problems of the conventional casting unit that is complicated to finish after assembly and casting are solved. A molten metal inlet 16 into which the molten metal flows into the cavity 14 formed inside forms a plurality of cores 12 having an opening on the surface, and a molten metal inlet between each of the molten metal inlets 16 and the spout cup 18 into which the molten metal is poured. The vanishing model 20 having a fireproof coating agent applied to its peripheral surface is a casting unit embedded in the dry sand 24 except for the spout cup 18, and the plurality of cores 12, 12,. Are adjacent to each other so that they are integrated.

Description

  The present invention relates to a casting unit and a casting method.

As a casting method, a vanishing model casting method using a vanishing model made of a resin such as polystyrene foam is known.
In such a disappearance model casting method, a casting unit shown in FIG. 17 is used. In the casting unit shown in FIG. 17, a faucet cup 108 in which a vanishing model made of a resin such as styrene foam forming a product portion 102 and a runner 104 is installed in a metal flask 100 at the front end portion of the runner 104. Is embedded in the dry sand 106.
In the dry sand 106, a plurality of through holes 110a, 110a,... Having a diameter smaller than the particle size of the dry sand 106 are formed so as to collect and discharge the decomposition gas generated when the lost model comes into contact with the molten metal. A cylindrical body 110 is inserted into the dry sand 106.
In the disappearance model casting method using the casting unit shown in FIG. 17, when molten metal is poured into the spout cup 108, the resin such as polystyrene foam that forms the disappearance model is thermally decomposed and disappeared by the heat of the molten metal, and the molten metal is removed from the product portion. 102 and runner 104 are filled.
Note that the pyrolysis gas of the resin such as polystyrene foam is collected in the cylindrical body 110 through the gap between the dry sand 106 and discharged.
In the vanishing model casting method using the casting unit shown in FIG. 17, it is possible to handle a plurality of cast products in an integrated manner, and thus the processing after casting is simple. However, since the disappearance model is usually formed by molding resin particles such as polystyrene foam, a trace pattern of resin particles is formed on the surface thereof. For this reason, the trace pattern of a resin grain may be transcribe | transferred on the surface of the obtained casting product. Accordingly, the surface of the obtained cast product needs to be polished.
Moreover, when the product part 102 is enlarged, a part of disappearance model may remain or wrinkles may occur. Part of the remaining disappeared model and soot may be mixed into the cast product. Casting products that contain part of the disappearance model or flaws are defective.
In contrast to such a conventional disappearance model casting method, as shown in FIG. 18, the following Patent Document 1 discloses a core 202 having a cavity 202a formed in a metal flask 200, and a core. 202, a feeder 202b connected to the cavity 202a, a vanishing gate 206 made of resin connected to the core 202, and a non-erasable runner product portion 102 connected to the vanishing gate 206. A casting method using a casting unit embedded in the dry sand 208 has been proposed.
In the casting unit shown in FIG. 18, a spout cup 210 exposed from the dry sand 208 is attached to the tip of the non-disappearing runner 204, and a decompression wire mesh pipe 212 is inserted into the dry sand 208. Has been.
Further, a film 214 for reduced pressure sealing is applied to the surface of the dry sand 208.

JP-A-6-226422

When casting using the casting unit shown in FIG. 18, if the molten metal is poured into the spout cup 210 while sucking from the decompression wire mesh pipe 212 to reduce the pressure in the flask 200, the non-disappearing runner 204 is formed. The molten metal flowing down is filled in the cavity 202a in the core 202 by thermally decomposing the resin forming the vanishing gate portion 206.
Pyrolysis gas generated by thermally decomposing the resin that forms the vanishable gate portion 206 and the resin that forms the core 202 is discharged from the decompression wire mesh pipe 212 through the gaps in the dry sand 208.
According to the casting unit shown in FIG. 18, it is possible to prevent the trace pattern of the resin particles from being transferred to the cast product. Further, the amount of disappearance model is small, and it is possible to prevent a part of the disappearance model from remaining or generation of wrinkles.
However, in the casting unit shown in FIG. 18, the non-disappearing runner 204 needs to be formed using a ceramic pipe faucet pipe, and the assembly and after-casting of the casting unit is complicated.
Further, when casting a cast product using a plurality of cores, it is necessary to provide a non-extinguishing branch pipe in the non-extinguishable runner 204, and the assembly of the casting unit and the subsequent cleaning after casting become more and more complicated. It becomes.
Accordingly, the present invention solves the problems of conventional casting units in which a non-disappearing runner is connected to an extinguishing gate attached to the core, and the assembly and casting are complicated, and the resin particles are added to the cast product. An object of the present invention is to provide a casting unit and a casting method capable of preventing the trace pattern from being transferred, a part of the disappearing model remaining, or the occurrence of wrinkles, and easy to clean after assembly and casting. And

The inventors of the present invention have studied to solve the above-mentioned problems. As a result, even if all the runners that connect each of a plurality of cores each having a cavity formed therein and a gate are formed by a vanishing model, FIG. Compared to the case where the runner 104 and the product part 102 are formed of a vanishable model as in the casting unit shown in FIG. For this reason, it has been found that the resin forming the disappearance model is sufficiently pyrolyzed by the molten metal poured into the spout cup, and the pyrolysis gas can be discharged to the outside through the gaps and cores of the dry sand.
Further, the present inventors have found that a plurality of cores can be integrated by joining cores adjacent to each other and handled as one object, and the present invention has been achieved.
That is, the present inventors, as means for solving the above-mentioned problems, are a plurality of cores having a molten metal inlet into which a molten metal flows into a cavity formed therein, and each of the molten metal inlets and the molten metal are poured. A casting unit that forms a runner between the gate and the peripheral surface and is coated with a fire-resistant coating agent, and is a casting unit that is embedded in dry sand except for the gate. It is possible to provide a casting unit in which cores adjacent to each other are joined so that the cores are integrated.
Further, as a means for solving the above-mentioned problem, after using this casting unit to pour molten metal into a pouring gate and casting, the dry sand is fluidized by vibration, and then the molten metal is formed in the runway formed by the disappearing model. It is possible to provide a casting method in which a cast product obtained by integrating a runner formed by filling and a product formed by filling each cavity of the core with molten metal is extracted from dry sand.
In the means for solving the problems provided by the present inventors, the following preferred embodiments can be raised.
A plurality of cores can be easily joined and integrated by joining the mutually adjacent cores with an adhesive or an uneven fitting.
As such a core, a core having a cavity formed therein can be easily formed by using a core composed of a pair of core molds. In particular, the core is preferably formed by a shell mold, a self-hardening mold or a combination of these.
Further, when the core is a shell mold, the cores adjacent to each other are bonded together by causing the resin contained in the shell sand to soften the softened layers and then curing them. Then, a plurality of cores can be joined very easily.
Furthermore, it can cast using a high temperature molten metal by apply | coating a fireproof coating type | mold to the inner wall face of the cavity formed in the core.
In addition, the core, runner, gate and dry sand are inserted into a metal flask, and the dry sand of the dry sand is collected so that the decomposition gas generated when the core and the disappearing model come into contact with the molten metal can be collected and discharged. The casting unit can be made compact by inserting a cylindrical body in which a plurality of through-holes having a diameter smaller than the particle diameter is formed into the dry sand.

Effect of the Invention According to the casting unit proposed by the present inventors, even if a runner that connects each of a plurality of cores each having a cavity formed therein and a gate is formed by a vanishing model, the gate cup is formed. The resin forming the disappearance model is sufficiently pyrolyzed by the poured molten metal, and the pyrolysis gas can be discharged to the outside through a gap or core of the dry sand. For this reason, it is possible to prevent a situation in which a part of the disappeared model remains or a part of the disappeared model is mixed with the cast product due to generation of soot.
Further, the plurality of cores can be integrated as a single object by joining the cores adjacent to each other, and can be handled as a single object, and the plurality of cores can be easily handled when the casting unit is assembled. .
Further, after casting, a cast product is formed in which a cast product formed by filling the core cavity with molten metal and a runner formed by filling the molten metal in the runner are integrated. For this reason, a cast can be easily pulled out from dry sand.

It is sectional drawing explaining an example of the casting unit which concerns on this invention. It is a front view about the cores 12 and 12 used with the casting unit shown in FIG. It is sectional drawing explaining the casting method using the casting unit shown in FIG. It is sectional drawing explaining the casting 30 pulled out from the dry sand 24 after casting using the casting unit shown in FIG. It is a front view explaining the alignment state when six cores 12 shown in FIG. 1 are used. It is a front view explaining the other example of the core 12 employable by this invention. It is explanatory drawing explaining an alignment state when six cores 12 shown in FIG. 6 are used. It is explanatory drawing explaining the apparatus which joins cores when a core is made into a shell mold. FIG. 3 is an explanatory view showing a first step of a method for forming a shell mold for joining cores together. It is explanatory drawing which shows the 2nd process of the continuation of FIG. It is explanatory drawing which shows the 3rd process following FIG. It is explanatory drawing which shows the 4th process of a continuation of FIG. It is explanatory drawing which shows the 5th process of the continuation of FIG. It is explanatory drawing which shows the 6th process of the continuation of FIG. It is explanatory drawing which shows the 7th process following FIG. FIG. 16 is an explanatory diagram showing an eighth step that follows FIG. 15. It is sectional drawing of the conventional casting unit used in a vanishing model casting method. It is sectional drawing of the conventional casting unit which used the core and the vanishing model together.

An example of a casting unit according to the present invention is shown in FIG. In the casting unit shown in FIG. 1, two cores 12 and 12 are inserted into a metal flask 10. 2, each of the cores 12 and 12 is formed by connecting a pair of core molds 12a and 12b, and a cavity 14 is formed therein. The weir 16 as a molten metal inlet into which the molten metal flows into the cavity 14 of the core 12 is formed along the parting line of the core molds 12a and 12b at the position of the inclined surface on the upper surface side of the core 12. Yes. The weir 16 may be formed at any location other than the parting line depending on the shape of the core 12.
By applying a fireproof coating agent to the inner wall surface of the cavity 14, casting using a high temperature molten metal such as stainless steel can be performed.
As the pair of core molds 12a and 12b, a shell mold, a self-hardening mold, or a combination of these can be used.
Further, the cores 12 and 12 shown in FIGS. 1 and 2 are integrated by joining a part of their outer peripheral surfaces with an adhesive, so that the cores 12 and 12 can be handled as one object.
A runner is formed by the disappearance model 20 between the weir 16 formed in each of the cores 12 and 12 and the ceramic sprue cup 18. The disappearance model 20 is formed of a resin such as expanded polystyrene. The inverted triangular portion 20a that contacts the weirs 16 and 16 of the cores 12 and 12 of the vanishing model 20 has a thicker portion thicker than the other portions of the vanishing model 20 and forms a feeder part. Part. Further, in the case where the inverted triangular portion 20a of the runner is located on the parting line of the core 12, and the cores 12 and 12 are integrated, the core 12 , 12 of the runners abutting against the weirs 16, 16 can be formed with a mold integral with the cores 12, 12 instead of the vanishing model.
The gate cup 18 may be a shell type or a self-hardening type.
Further, a vanishing model 22 that forms a spout feeder is connected to a hole that is opened on each upper surface of the cores 12 and communicates with the cavity 14. Although a hole is formed along the parting line of the core 12 shown in FIGS. 1 and 2, the hole may be formed at any location other than the parting line depending on the shape of the core 12. It is to be noted that this is a case where the hole that communicates with the cavity 14 formed on the upper surface of the core 12 is opened on the parting line of the core 12, and the plurality of cores 12, 12 are integrated. In this case, the squeeze feeder part connected to the hole can be formed not by the disappearance model but by a mold integrated with the cores 12 and 12.
A fireproof coating agent that is not melted or thermally decomposed by the molten metal poured into the spout cup 18 is applied to the outer peripheral surfaces of these disappearance models 20 and 22. Therefore, when the disappearance models 20 and 22 are thermally decomposed and disappeared by the molten metal poured into the spout cup 18, the fire-resistant coating agent forms the outer peripheral surface of the runner and the spout feeder.
Note that the inverted triangular portion 20a of the disappearance model 20 and the portions including the weirs 16 and 16 of the cores 12 and 12 are connected by an adhesive.
In the casting unit shown in FIG. 1, the cores 12 and 12, the disappearance model 20 that forms the runner, and the disappearance models 22 and 22 that form the spout feeder are the spout cups that are attached to the tip of the disappearance model 20. It is embedded in the dry sand 24 except for 18.
A cylindrical body 26 in which a plurality of through holes 26 a, 26 a... Having a smaller diameter than the dry sand 24 is formed is inserted into the dry sand 24. This is because the cores 12 and 12 and the disappearance models 20 and 22 collect and discharge the decomposition gas generated when they contact the molten metal.
By the way, when the cores 12 and 12, the disappearance model 20 and the disappearance models 22 and 22 are embedded in the dry sand 24, the cores 12 and 12, the disappearance model 20 and the disappearance models 22 and 22 are placed in the flask 10. After filling the predetermined amount of dry sand 24 or while filling the predetermined amount of dry sand 24, by applying vibration to the flask 10, the gaps between the cores 12, 12 and the disappearance models 20, 22, 22 are also provided. The dry sand 24 can be sufficiently filled.
When the molten metal is poured into the spout cup 18 of the casting unit shown in FIG. 1, the disappearance model 20 disappears by pyrolysis as shown in FIG. 3, but the heat resistant coating applied to the outer peripheral surface of the disappearance model 20. The runner 32 is formed without the molten metal permeating into the dry sand 24 by the mold. In the vicinity of the cores 12, 12 of the runway 32, a hot water feed portion 32 a having a thicker portion thicker than the runway 32 is formed by an inverted triangular portion 20 a.
The molten metal in the runner 32 enters and fills the cavity 14 in the core 12 from the weirs 16 of the cores 12 and 12. Further, the molten metal in the cavity 14 comes into contact with the disappearing model 22 attached to the hole of the cavity 14, disappears the disappearing model 22, and forms a spout feeder 34.
When the molten metal is filled, the resin components forming the disappearance models 20 and 22 and the cores 12 and 12 are thermally decomposed by the heat of the molten metal, and a pyrolysis gas is generated. This pyrolysis gas passes through the gap formed between the particles of the dry sand 24 and is collected in the cylindrical body 26 via the through holes 26a, 26a,. Discharged outside.
In addition, by providing an ignition source such as an electric spark in the vicinity of the outlet of the cylindrical body 26, the pyrolysis gas discharged from the cylindrical body 26 can be burned.
When each of the cavities 14 of the cores 12 and 12 is sufficiently filled with molten metal, pouring of the molten metal into the spout cup 18 is stopped, and the molten metal filled in the cavity 14 is cooled.
When the molten metal filled in the cavity 14 is cooled, a gap may be formed in the cavity 14 due to contraction accompanying the progress of the cooling of the molten metal. The gap is filled with the molten metal supplied from the hot metal portion 32 a or the squeezed hot water portion 34 where the molten molten metal is stored.
When cooling of the molten metal filled in the cavities 14 and the like is completed, as shown in FIG. 3, the cast product P formed in each cavity 14 of the cores 12 and 12 and the molten metal are filled in the runner 32. A cast product in which the runner 36 is integrated can be obtained.
The cast product can be extracted from the dry sand 24 after the dry sand 24 is fluidized by vibration.
The casting 30 shown in FIG. 4 extracted from the dry sand 24 has a hot water portion 36a (a portion formed by the hot water portion 32a) formed at the front end portion of the runner 36 extended from the pouring cup 18. Cast products P and P formed in the sub-elements 12 and 12 are connected via casting weirs 38 and 38 formed by the weirs 16 and 16.
The cast product 30 can be removed from the runner 36 by tapping the cores 12 and 12, and at the same time, the cores 12 and 12 are also broken and the cast products P and P are taken out. Can do.
On the outer peripheral surface of the cast products P, P taken out from the cores 12, 12, skein feeder parts 40 a, 40 a formed by the skein feeder part 34 are formed so as to protrude. Such spout feeder parts 40a, 40a can be easily removed by simple excision / breaking or the like.
As described above, since the cores 12 and 12 are integrated by the adhesive, the cores 12 and 12 can be handled as one object, and the assembly and cleaning of the casting unit shown in FIG. 1 is easy. It is.
Further, the obtained cast products P and P had a smooth surface, and part of the remaining disappearance models 20 and 22 and soot were not mixed.
Even when the cores 12, 12 are not broken when the cores 12, 12 are removed from the runner 36, the members forming the cores 12, 12 come into contact with the molten metal and the organic matter such as the adhesive is heated. Since the strength is reduced by being decomposed, the cores 12 and 12 can be easily broken, and the cast products P and P can be taken out.
1 to 4 use two cores 12 and 12, FIG. 5 shows an example using six cores 12, 12,... In FIG. 5, the cores 12, 12... Are arranged so that the weirs 16 face each other, and are joined and integrated with the adjacent cores 12 by an adhesive. Therefore, the six cores 12, 12,... Can be handled as one object.
In addition, an inverted triangular portion 20a formed at the end of the core 12 side of the vanishing model 20 forming the runner is a portion that serves as a feeder, and the aligned cores 12, 12,. Of these, the cores 12 and 12 arranged at the center are connected to the weirs 16.
Further, disappearance models 20b and 20b extend in the direction of the cores 12, 12... Arranged in the left-right direction from the portion 20a disposed in the cores 12 and 12 in the central part. An inverted triangular portion 20a is formed at a predetermined location of the disappearance models 20b, 20b so as to be connected to the respective weirs 16 of the cores 12, 12,.
By using the cores 12, 12... And the disappearance models 20, 20 a, 20 b shown in FIG. 5, the six cores 12, 12 in which the cast product P is formed at the tip of the runner 36 after casting. .. Can be obtained.
Moreover, although the mutually adjacent cores 12 and 12 are connected by the adhesive agent, the core 12 shown in FIG. 6 can be used for the plurality of cores 12 shown in FIGS. . The core 12 shown in FIG. 6 is formed by a pair of core molds 12a and 12b. A concave portion 50 and a convex portion 52 are formed on the outer peripheral surface of the core 12.
When using the plurality of cores 12, 12,... Shown in FIG. 6, the concave portion 50 formed on the outer peripheral surface of the core 12 and the convex portion 52 of the adjacent core 12 are concavo-convexly fitted. A plurality of cores 12, 12,... Can be handled as one object.
Note that an adhesive may be used in combination when the concave portion 50 formed on the outer peripheral surface of the core 12 and the convex portion 52 of the adjacent core 12 are concavo-convexly fitted.
Further, as a method of connecting the adjacent cores 12 with respect to the plurality of cores 12, 12... Shown in FIGS.
When a pair of shell molds are used as the core 12, the cores 12 are joined together by bringing the softened layers of the shell mold including the softened layer in a state where the resin contained in the shell sand is softened together. It can be carried out.
A mold formed by a shell mold method using shell sand is generally referred to as a shell mold. As the shell sand, dry sand mixed with phenol resin, hexamine or the like is used. Shell sand is dried and granulated at room temperature, but softens when heated to exceed the melting point of the resin. When the shell sand in the softened state is further heated, it hardens.
In order to mold such a shell mold joined together, vibration is applied to the shell sand, two molds heated from above the vibrating shell sand are pushed in, and the two molds are shelled. A shell mold including a hardened layer formed by curing on the molding surface of each mold after a predetermined time has passed after being pushed into the sand, and a softened layer in which the resin contained in the shell sand is softened around the hardened layer Each mold can be raised from the shell sand and the softened layers can be brought into close contact with each other.
The shell mold making method described above will be described in more detail below.
As shown in FIG. 8, the shell sand 85 constituting the shell mold is stored in the shell sand container 21. The shell sand container 21 is provided with a vibration applying device 88 that applies vibration to the shell sand 85 in the shell sand container 21. As the vibration applying device 88, a vibration motor or the like is used.
By vibrating the shell sand 85 with the vibration applying device 88, the friction between the particles of the shell sand 85 can be reduced and fluidized, and the two molds 82 and 84 can be easily moved from above into the shell sand 85. Can be pushed into.
The molds 82 and 84 to be pushed into the shell sand are disposed above the shell sand container 21 so that the molding surfaces 51 and 54 are positioned facing downward. Concave portions 19 that are recessed toward the molding surface side are formed on the back surfaces (opposite surface of the molding surface: upper surface) of the molds 82 and 84.
The upper portions (back side) of the molds 82 and 84 are continuous with the recesses 19 of the molds 82 and 84, and a chamber 86 that is closed from the external space is formed. A heater 80 as an example of a heating device is disposed in the chamber 86. The heater 80 can employ an electric heater or the like, and can heat the air in the chamber 86.
The chamber 86 is configured such that the periphery thereof is covered with a frame 27 that stands in the vertical direction above the molds 82 and 84 and surrounds the periphery of the chamber 86, and a ceiling plate 53 that covers the upper end surface of the frame 27. The chamber 86 has a bottom surface covered with molds 82 and 84, a side surface covered with the frame 27, and an upper surface covered with the ceiling plate 53. The frame 27 and the ceiling plate 53 constitute a chamber component.
The molds 82 and 84 are fixed to the flange 13 protruding inward of the frame 27 by bolts or the like. As the material of the molds 82 and 84, aluminum having high thermal conductivity can be used. Moreover, since aluminum is lighter than other metals, the weight can be further reduced by forming the recess 19 and the handling becomes easy.
Inside the chamber 86, an extrusion pin 78 for removing the molded shell molds A and B (see FIG. 15) from the molds 82 and 84 is arranged. Since the push pin 78 is disposed in the chamber 86, it is heated in the same manner as the molds 82 and 84.
An upper end portion of the push pin 78 passes through the ceiling plate 53. An upper end portion of the push pin 78 penetrating the ceiling plate 53 is fixed to the push plate 56. A lower end portion of the push pin 78 is disposed so as to protrude from a through hole formed in the flange 13 of the frame 27. Under normal conditions, the lower end portion of the push pin 78 is located on the same plane as the lower surface of the flange 13.
The extrusion plate 56 is provided above the ceiling plate 53 so as to be always urged upward with respect to the ceiling plate 53 by urging means 59 such as a spring.
An extrusion cylinder 58 for operating the extrusion pin 78 is provided above the extrusion plate 56. The cylinder 58 for extrusion is attached to the cylinder fixing | fixed part 60 fixed to the ceiling board 53 above the extrusion plate 56, and the rod 58a is being fixed to the extrusion plate 56. FIG.
When the pushing cylinder 58 is operated, the rod 58a pushes down the pushing plate 56 against the urging force of the urging means 59. Then, the push pin 78 fixed to the push plate 56 descends, and its tip protrudes from the through hole. The extrusion pin 78 protruding from the through hole presses the molded shell molds A and B (see FIG. 15) and removes them from the molds 82 and 84.
In the above-described embodiment, the heating in the chamber 86 is performed by the heater 80, and therefore the heated air outflow from the chamber 86 between the ceiling plate 53 and the flange 13 where the extrusion pin 78 passes is prevented. You don't have to consider too much.
However, when superheated steam or heated air is blown into the chamber 86, the pressure in the chamber 86 increases, so that the superheated steam or heated air is passed through the ceiling plate 53 or the flange 13 where the extrusion pin 78 penetrates. It is necessary to seal so that it does not erupt from between. In such a case, it is preferable that the extrusion pin 78 is not exposed in the chamber 86 by integrally covering the periphery of the extrusion pin 78 with a member constituting the frame 27 or the molds 82 and 84.
Each chamber component, including the molds 82 and 84, is attached to the articulated robot arm 70 so that it can freely rotate in the vertical plane, move in the horizontal direction, and move in the vertical direction. It is attached.
The tip of the robot arm 70 is provided with a rotating means 71 such as a motor, and the rotating shaft of the rotating means 71 is connected to the chamber component. By rotation of the rotation means 71, the chamber constituent parts can face the bottom surfaces of the shell molds formed around the molds 82 and 84 to face each other.
Further, on the rear end side of the rotation means 71 of the robot arm 70, a rotation means 72 having a rotation axis formed in a direction orthogonal to the rotation axis of the rotation means 71 is provided. Further, on the rear end side of the rotation means 72, a rotation means 74 having a rotation axis facing in the same direction as the rotation means 71 at the front end is provided.
By rotation of the rotation means 72, each chamber component can move the molds 82 and 84 between the back side and the near side in FIG. For this reason, the bottom surfaces of the shell molds can be joined with a slight shift.
Further, by the turning operation of the turning means 74 and the turning means 71 at the distal end, each chamber component can move the molds 82 and 84 in the vertical direction and the horizontal direction.
Although the rear end portion of the robot arm 70 is omitted, the robot arm 70 is attached to a rotating means (not shown) whose rotating shaft is oriented in a predetermined direction. The molds 82 and 84 can be moved up and down by the turning operation.
In addition, as each rotation means 71, 72, 74, the rotation mechanism by a motor, a cylinder, etc. are mentioned.
The process of joining the shell mold in the present embodiment will be described with reference to FIGS. Here, configurations other than the molds 82 and 84 and the shell sand container 21 are omitted.
First, at the time of FIG. 9, the air in the chamber 86 is heated by the heater 80 in the chamber 86 on the back surface of the molds 82 and 84. The temperature in the chamber 86 is set to about 250 to 300 ° C.
The vibration applying device 88 is driven to apply vibration to the shell sand 85 in the shell sand container 21 until the molds 82 and 84 are lowered into the shell sand container 21.
As shown in FIG. 10, when the mold temperature is heated to about 250 ° C. to 300 ° C., the robot arm 70 lowers the molds 82 and 84. Then, when the upper end surface of the molding surfaces of the molds 82 and 84 is buried in the shell sand 85, the vertical movement operation is stopped. At this time, the vibration applying operation of the vibration applying device 88 is stopped together with the stop of the vertical movement operation.
At this time, the heating device 30 continues heating so that the inside of the chamber 86 becomes a constant temperature based on the temperature detected by a temperature sensor (not shown) that detects the temperatures of the molds 82 and 84.
As shown in FIG. 11, the shell sand existing around the molding surfaces of the molds 82 and 84 is heated, and the shell sand is cured in accordance with the shape of the molding surfaces of the molds 82 and 84. At this time, only the vicinity of the molds 82 and 84 is cured as the cured layers Aa and Ba, and the surroundings are formed as the softened layers Ab and Bb in a state where the resin is dissolved and not cured. When a predetermined time set in advance elapses, the robot arm 70 raises the molds 82 and 84.
Then, as shown in FIG. 12, when the molds 82 and 84 are raised, the shell mold A having the hardened layers Aa and Ba and the softened layers Ab and Bb formed in the shape of the molding surface of the molds 82 and 84, B rises with the molds 82 and 84. In addition, although granular shell sand may adhere to the outer surface of the softening layers Ab and Bb that are rising, they fall into the shell sand container 21 during or after the rising. In order to drop the shell sand, a vibration applying device (not shown) may be provided in the chamber component. When the vibration applying device vibrates the chamber component, the molds 82 and 84 vibrate, and unnecessary shell sand attached to the softened layers Ab and Bb can be easily dropped.
As shown by the arrows in FIG. 12, the rotating means 71 of the robot arm 70 or other rotating means of the robot arm is also interlocked so that the shell molds A and B arranged in the molds 82 and 84 are mutually connected. Rotate to face the bottom of
Thus, as shown in FIG. 13, the bottom surfaces of the shell molds A and B are positioned so as to face each other. At this time, the softened layers Ab and Bb still exist in each of the shell molds A and B.
As shown in the direction of the arrow in FIG. 13, after the bottom surfaces of the shell molds A and B face each other, the robot arm 70 causes the chamber components to approach each other.
Then, as shown in FIG. 14, the softened layers Ab and Bb of the shell molds A and B are brought into close contact with each other so that the softened layers Ab and Bb can be heated by the molds 82 and 84 without using an adhesive or the like. And the two shell molds A and B can be bonded satisfactorily.
In FIG. 15, the shell molds A and B whose bottom surfaces are joined by the contact / separation moving means are fired. In each of the shell molds A and B, the softened layers Ab and Bb are gradually cured by heat from the respective molds 82 and 84. However, the softened layers Ab and Bb bonded to each other can be heated and fired from the outside by the firing device 35 to promote curing.
Then, as shown in FIG. 16, the shell molds A and B in which the above-described extrusion pins 78 are formed are pushed out and removed from the raised molds 82 and 84, and the bottom surfaces of the shell molds A and B are bonded to each other. The molding of the shell mold U is completed.
As described above, according to the method in which the softened layers of the resin are in close contact with each other in the manufacturing process of the shell mold, there is no need for labor as compared to the case of using an adhesive or the case of forming an uneven fitting, and a plurality of simple The shell mold can be joined.

Claims (8)

On the peripheral surface, forming a runway between a plurality of cores whose melt inlets flow into the cavity formed therein and whose melt inlets open on the surface, and each of the melt inlets and a spout into which the melt is poured. The disappearance model coated with a fire-resistant coating agent is a casting unit embedded in dry sand except for the gate,
A casting unit characterized in that adjacent cores are joined so that the plurality of cores are integrated.   The casting unit according to claim 1, wherein cores adjacent to each other are joined together by an adhesive or an uneven fitting.   The casting unit according to claim 1 or 2, wherein the core is a core composed of a pair of core molds.   The casting unit according to any one of claims 1 to 3, wherein the core is a shell mold, a self-hardening mold, or a mold in which these are combined. When the core is a shell mold,
The casting unit according to claim 4, wherein the cores adjacent to each other are bonded together by allowing the softened layers in a state where the resin contained in the shell sand is softened to adhere to each other and then curing.   The casting unit according to any one of claims 1 to 5, wherein a fireproof coating agent is applied to an inner wall surface of a cavity formed in the core.   The diameter of the dry sand is such that a core, a runner, a sprue, and dry sand are inserted into a metal flask, and the core and the disappeared model can collect and discharge the decomposition gas generated in contact with the molten metal. The casting unit according to any one of claims 1 to 6, wherein a cylindrical body in which a plurality of through holes having a smaller diameter is formed is inserted into the dry sand. Using the casting unit according to any one of claims 1 to 7, after pouring the molten metal into the gate and casting, the dry sand is fluidized by vibration,
Next, a cast product obtained by integrating the runner formed by filling the molten metal into the runner formed by the disappearance model and the product formed by filling each cavity of the core is extracted from the dry sand. A casting method characterized by the above.

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