JP2011240351A - Evaporative pattern and method for manufacturing casting - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technique for an evaporative pattern and a method for manufacturing a casting, which facilitates a sand fill work performed when embedding the evaporative pattern into a sand mold and also improves quality (casting quality) of a molten casting product.SOLUTION: The evaporative pattern 1 includes: an operation part 2 corresponding to a first part where a load from the outside is directly subjected to, in the casting product; and a framework 3 corresponding to a second part for holding the first part, in the casting product. The framework 3 includes multiple bar members 31, 31... and multiple couplers 32, 32... for coupling the multiple bar members 31, 31... with each other, and is configured to be a polygonal assembly constituted of the bar members 31, 31... The operation part 2 is coupled with the framework 3 via the couplers 32, 32... The operation part 2, the couplers 32, 32..., and the bar members 31, 31... are made up of a member that disappears after being burned by a molten metal 64 for casting the casting product.

Description

The present invention relates to a vanishing model and a technique of a manufacturing method of a casting cast using the vanishing model.
More specifically, the present invention relates to a technology for a disappearance model and a method for manufacturing a casting for improving the quality (casting quality) of a cast product while facilitating sand filling work when the disappeared model is embedded in a sand mold. .

Conventionally, it has a complicated shape, such as a press die, a welding equipment base, and a surface plate for precision measurement jigs, and requires high rigidity against external forces (loads) received during use. For the parts to be used, castings formed by casting are often used.
Moreover, in recent years, as a means for casting such castings, it is possible to shorten the molding time (time required for molding a sand mold) without requiring a core, or to cast a complex shape. On the other hand, a casting method by a full mold method (FM method: Full Mold method) has been attracting attention because it can be easily handled (see, for example, “Patent Document 1”).

The full mold method is a method of casting a casting while replacing a model embedded in a sand mold (hereinafter referred to as “disappearance model”) and a molten metal poured into the sand mold.
That is, in the full mold method, a casting model to be obtained in advance is formed as a vanishing model using an organic material such as polystyrene resin (so-called foamed polystyrene), and the sand mold is formed by embedding the vanishing model in the casting sand. To do.
Molten metal is poured into the molded sand mold without taking out the disappearance model. Then, the disappearance model is burned by the heat generated by the molten metal and disappears, and is replaced with the disappearance model and the molten metal is filled in the sand mold.
Thereafter, the molten metal is cooled together with the sand mold, and a casting corresponding to the shape of the disappearing model is cast.

Here, in the casting cast by such a full mold method, the structure of the disappearance model 100 formed when casting is described with reference to FIG. 4, taking a conventional press die as an example.
4A and 4B are schematic views showing the overall configuration of the vanishing model 100, where FIG. 4A is a plan view of the vanishing model 100, and FIG. 4B is a side view of the vanishing model 100 viewed from the arrow Y in the plan view. The figure is shown.
In addition, regarding the following description, the direction of the arrow A in FIG.
Moreover, in the side view of FIG.4 (b), the up-down direction on drawing is prescribed | regulated as the up-down direction of the vanishing model 100, and it demonstrates below.

The disappearance model 100 is made of polystyrene foam, and is accurately cut and imitated using a cutting machine or the like according to the shape of a press die (casting) to be cast.
Here, the conventional press die (casting) is constituted by a first part that directly receives a load from the outside during the pressing process, a second part provided to hold the first part, and the like. Is done.
Therefore, the disappearance model 100 is configured to include a functional unit 101 (a portion indicated by shading in FIG. 4) corresponding to the first part, a housing part 102 corresponding to the second part, and the like. Is done.

The functional unit 101 includes a plurality of press units 111, 111, etc., inserted portions 112, 112, contacted portions 113, 113, and the like.
The press portion 111 corresponds to a portion of a conventional press die (casting) that is pressed against a workpiece (a sheet-like member that is pressed by the press die).
In addition, the insertion portion 112 is inserted with a guide pin (not shown) for regulating the position of the press die (casting) in the horizontal direction during press working in a conventional press die (casting). Corresponds to the site.
Further, the contacted portion 113 is contacted with a contact stopper (not shown) for regulating the position of the press die in the vertical direction during press working in a conventional press die (casting). Corresponds to the site.

  Depending on the configuration of the press mold (casting) to be cast, these guide pins and contact stoppers may be provided in a press machine (not shown) for fixing and holding the press mold (casting). In the disappearance model of the press die (casting) having such a configuration, the functional unit 101 is configured only by a plurality of press units 111, 111.

The casing portion 102 has a rectangular box structure, and most of the lower surface portion is opened, and a plurality of flat plate portions 102a, 102a,.
Moreover, inside the housing part 102, a plurality of rectangular space parts 121, 121... Partitioned by these flat plate parts 102a, 102a... And the upper surface part 102b of the housing part 102 are housings. It is formed in a lattice shape in plan view over substantially the entire inside of the portion 102.

Note that the internal configuration of the housing 102 is not limited only by these space portions 121, 121,..., For example, a part of the side surface of the housing 102 includes an upper surface 102b and a flat plate 102a. And a space 122 having a U-shape in side view, which is partitioned by a lower plate piece (not shown).
In addition, depending on the configuration of the press mold (casting) to be cast, for example, by a plate portion 102c that is curved in a plan view, in order to secure a storage space for equipment mounted in the press mold (casting) , A part of these space portions 121, 121... May be formed, or although not shown, a space portion having a trapezoidal shape or a circular shape in plan view may be formed.

  The press portions 111, 111,... Are respectively disposed at predetermined positions in the central portion in plan view on the upper surface portion 102b of the housing portion 102, and the inserted portions 112, 112 and the contacted portions are provided at the four corners. The vanishing model 100 is configured by arranging 113 and 113 so as to face each other diagonally.

Using the disappearance model 100 having such a shape, a conventional press die (casting) is cast according to the shape of the disappearance model 100.
As a result, in a conventional press die (casting), the portions corresponding to the flat plate portions 102a, 102a,... Of these disappearance models 100 function as a kind of reinforcing material, and the press die (casting) is a casing portion. 102 has a configuration having high rigidity as a whole.

By the way, when casting castings, such as a press die, by the full mold method using the disappearance model which consists of such a shape, the following various problems were pointed out.
In other words, depending on the type of casting, there is a large casting such as a press die having a length of several meters. On the other hand, the foundry sand contains a solidified material for hardening the foundry sand in advance. Before solidifying, the operation of burying the disappearing model in the foundry sand must be completed.
In such a case, the worker maintains an unnatural posture consisting of a crawling or hungry state, completes the sand crushing work immediately, and then performs the work of burying the disappeared model in the foundry sand for a long time. Must continue.
Therefore, it is a physically demanding work for the operator, and it has been necessary to improve the work so that the disappearance model can be buried with an easy posture.

In addition, the vanishing model has a complicated shape similar to a cast cast such as a press mold, and in order to embed such a vanishing model in the foundry sand without a gap, the vanishing model is previously formed with a fingertip. It is necessary to press the foundry sand into the details (sanding work).
Here, depending on the shape of the disappearance model, the details may exist in a place that is out of the reach of the worker performing the sanding work, and a dedicated tool is used to press the foundry sand against such details. It is necessary to perform sanding work.
Therefore, depending on the shape of the vanishing model, the casting quality of the cast casting will depend on the maturity level of the skill and skill of the worker performing the sanding work and the arm strength, etc., and ensure a uniform casting quality It was difficult.

In addition, if the density of the foundry sand pressed against the details of the disappearance model is not sufficiently increased, if molten metal is poured into the sand mold after the completion of the disappearance model embedding operation, a crack occurs in the foundry sand, Molten metal is ejected to the outside of the sand mold, or casting sand is caught in the casting, which causes a reduction in casting quality.
For this reason, when performing the sand filling operation, it is necessary to press the foundry sand against the details of the lost model with a considerably large pressing force to increase the density of the foundry sand.
However, since the disappearance model is made of foamed polystyrene, when the molding sand is pressed with a large pressing force, the shape of the disappearance model is deformed (or distorted), which is a factor causing deterioration in casting quality. It was.

Further, in FIG. 4, the press mold (casting) requires high rigidity. Strictly speaking, the press mold (casting) is placed on the functional part 101 of the disappearance model 100 and the periphery of the functional part 101. It suffices that only the corresponding portion has high rigidity, and there are portions that do not require such a high rigidity in other portions.
However, in the structure of the conventional press mold (casting), as described above, the portion corresponding to the flat plate portions 102a, 102a,... Of the disappearance model 100 functions as a kind of reinforcing material. The mold (casting) is configured to have high rigidity as a whole through a portion corresponding to the casing 102 of the disappearance model 100.
Thus, the press die (casting) is configured to excessively increase the rigidity, and is a large and heavy metal die as a whole.
On the other hand, in order to reduce the weight of the press die (casting), it is also conceivable to reduce the thickness (reducing the thickness of the portion) of the portion that does not require much rigidity.
However, if the specific part is thinned, the part corresponding to the part in the disappearance model 100 also needs to be thinned. In this case, distortion or the like is likely to occur in the thinned portion of the disappearance model 100, and the entire disappearance model 100 is easily deformed. As a result, the casting quality may be reduced.
For this reason, the disappearance model 100 for imitating the shape of the press die (casting) is also large-scale, difficult for the operator, and makes it difficult to embed the disappearance model in the foundry sand.

In addition, when the molten metal is poured into the sand mold after completion of the operation of burying the lost model in the sand mold, the lost model is burned and vaporized by the heat generated by the molten metal to generate gas.
Here, as described above, when the disappearance model having a large structure is used, the amount of gas generated from the disappearance model becomes large, and the molten metal molten metal flow is hindered by the resistance of the gas. It becomes a factor causing deterioration of casting quality. In particular, on the downstream side of the hot water flow, the generated gas is difficult to escape to the outside of the sand mold, and the cooling of the molten metal that has reached the downstream side is started early, so that impurities are mixed into the casting. In addition, it was easy to generate bubbles, and it was easy to cause deterioration of casting quality.

Further, in FIG. 4, since the press mold (casting) requires high rigidity, the casing portion 102 of the disappearance model 100 imitated according to the shape of the press mold (casting) has a sufficient thickness dimension. This is a large-scale structure having a dimension from the lower surface to the upper surface of the casing 102.
Therefore, as the thickness dimension of the entire disappearance model 100 (the dimension from the lower surface of the housing part 102 to the uppermost end part of the functional part 101. That is, the dimension Z shown in the side view of FIG. 4B) is about 500 mm to 600 mm. In many cases, the size is larger than that.
On the other hand, many processing equipment such as a cutting machine used for modeling the disappearance model 100 cannot model such an disappearance model having a thickness of about 500 mm to 600 mm or more at a time. .
From such a thing, in the modeling process of the disappearance model 100, first, a plurality of plate-shaped foamed polystyrenes are respectively modeled by processing equipment, and then these shaped foamed polystyrenes are sequentially laminated and adhered to each other, thereby disappearing. The model 100 was formed (modeled).
Therefore, when laminating these shaped polystyrene foams, it is difficult to accurately position each other polystyrene foam, which may cause deterioration in casting quality.
On the other hand, in order to avoid such a deterioration in casting quality, it is also possible to provide a large processing facility capable of forming the disappearing model 100 having a thickness of about 500 mm to 600 mm or more at a time. However, the equipment cost is enormous and it is not realistic.

Furthermore, a coating agent is applied to the surface portion of the disappearance model for the purpose of protecting the disappearance model from the heat generated by the molten metal or improving the casting surface of the casting to be cast. As described above, when the disappearance model becomes large, the amount of the coating agent applied increases accordingly.
As a result, the disappearance model is likely to be distorted due to the weight of the coating agent, which may lead to a deterioration in casting quality.

  As means for improving the various problems described above, techniques disclosed in “Patent Document 2” to “Patent Document 4” have been proposed.

  That is, in “Patent Document 2”, a molding core (disappearance model) used for forming a molded product (casting) such as a cast product having a hollow shape or an undercut shape, etc. A technique relating to a pressure-resistant collapsible core (disappearance model) for molding is disclosed, wherein the core is provided with a pressure-resistance formed from a collapsible material such as paper, fiber, or grain. .

  In “Patent Document 3”, a model (disappearance model) put in a sand mold is completely extinguished by combustion, and a cavity is formed in order to cast molten metal after the cavity is formed. A technique related to a mold forming method is disclosed, wherein the composition of the material constituting the model is a composite of wood powder or paper powder and a thermoplastic synthetic resin.

  Moreover, in "patent document 4", it is a disappearance model formed by combining a plurality of elements (plate-like foamed polystyrene), and among the elements combined with each other, on the mating surface of one element, Disclosed is a technique related to a vanishing model characterized in that a positioning pin formed of the same material as an element is erected and a positioning hole for fitting the projection is provided on a mating surface of the other element. ing.

JP 2000-71050 A JP 7-214240 A Japanese Patent Laid-Open No. 7-204779 JP 2007-152419 A

According to the techniques disclosed in the “Patent Document 2” to “Patent Document 4”, it is considered that a large amount of capital investment is not required and the casting quality can be improved.
That is, according to the technique disclosed in the above-mentioned “Patent Document 2”, the choice of materials used for the disappearance model is increased, and an appropriate material is selected that suppresses the amount of gas generated when pouring molten metal into the sand mold. By doing so, it seems that the casting quality can be improved without requiring a large capital investment.
However, as long as the structure of the casting is large, such as the press mold described above, the shape of the disappearance model becomes large. Therefore, such a disappearance model is difficult to handle for an operator, and the burying operation of the disappearance model in the foundry sand cannot be improved easily.
Moreover, even in the sanding work, there is no difference in the fact that it depends largely on the skill of the operator using special tools such as cans and tips. For this reason, the casting quality depends on the maturity level of the worker's skill with respect to the sanding work and the arm strength. Therefore, it is difficult to ensure uniform casting quality.

In addition, according to the technique disclosed in the above-mentioned “Patent Document 2”, pouring molten metal into the sand mold is started after the disappearance model in the sand mold is completely extinguished. It seems that the generated gas does not hinder the molten metal flow and can prevent the casting quality from deteriorating.
However, as in the technique disclosed in the “Patent Document 2”, as long as the structure of the casting is large, the shape of the disappearance model becomes large. Therefore, such a disappearance model is difficult to handle for an operator, and the burying operation of the disappearance model in the foundry sand cannot be improved easily.
Moreover, even in the sanding work, there is no difference in the fact that it depends largely on the skill of the operator using special tools such as cans and tips. For this reason, the casting quality depends on the maturity level of the worker's skill with respect to the sanding work and the arm strength. Therefore, it is difficult to ensure uniform casting quality.

Furthermore, according to the technique shown in the above-mentioned “Patent Document 3”, even if the configuration of the disappearance model is a plurality of plate-shaped foamed polystyrenes, each of which is laminated by laminating these shaped foamed polystyrenes. In doing so, it becomes possible to accurately position the foamed polystyrene, and it seems that the casting quality can be prevented from being lowered.
However, as in the technique disclosed in the “Patent Document 2”, as long as the structure of the casting is large, the shape of the disappearance model becomes large. Therefore, such a disappearance model is difficult to handle for an operator, and the burying operation of the disappearance model in the foundry sand cannot be improved easily.
Moreover, even in the sanding work, there is no difference in the fact that it depends largely on the skill of the operator using special tools such as cans and tips. For this reason, the casting quality depends on the maturity level of the worker's skill with respect to the sanding work and the arm strength. Therefore, it is difficult to ensure uniform casting quality.

  The present invention has been made in view of the above-described problems of the present situation, and in the disappearance model and the casting manufacturing method for casting using the disappearance model, sand when the disappearance model is embedded in a sand mold. It is an object of the present invention to provide a technique for a disappearance model and a method for manufacturing a casting for improving the quality (casting quality) of a cast casting while facilitating the filling operation.

  The problem to be solved by the present invention is as described above. Next, means for solving the problem will be described.

  That is, in claim 1, a vanishing model for casting a casting, wherein the vanishing model is a functional portion corresponding to a first portion that directly receives a load from the outside in the casting, and the casting model in the casting. A housing portion corresponding to a second portion for holding the first portion, and the housing portion includes a plurality of rod-shaped members and a plurality of connecting members that connect the rod-shaped members to each other. The rod-shaped member is formed as a polygonal aggregate, the functional unit is coupled to the housing unit via the coupling member, and the functional unit, the coupling member, and the rod-shaped member cast a casting. It is comprised with the member which burns and disappears with the molten metal which does.

  In Claim 2, it is an elimination | eradication model of Claim 1, Comprising: The said function part is modeled by a polystyrene foam.

  In Claim 3, it is a vanishing model of Claim 1 or Claim 2, Comprising: The said rod-shaped member is a hollow-shaped member.

  According to a fourth aspect of the present invention, there is provided a method for manufacturing a casting that is cast using the disappearance model, wherein the casting model is cast using the disappearance model, and the disappearance model directly receives a load from the outside in the casting. A functional part corresponding to the first part to be received and a housing part corresponding to the second part for holding the first part in the casting, and connecting the rod part to a plurality of rod-like members The members are connected to each other to form a polygonal aggregate formed by these rod-shaped members, the functional part is connected to the housing part via the connecting member, the functional part, the connecting member, and The rod-shaped member is composed of a member that burns and disappears by molten metal that casts a casting, the disappearance model is embedded in a sand mold, molten metal is poured into the sand mold, and the disappearance model is converted into the sand mold. Molten metal poured inside While substitution, is to cast castings.

  In Claim 5, it is a manufacturing method of the casting of Claim 4, Comprising: The said function part is modeled by a polystyrene foam.

  In Claim 6, it is a manufacturing method of the casting of Claim 4 or Claim 5, Comprising: The said rod-shaped member is a hollow-shaped member.

As effects of the present invention, the following effects can be obtained.
That is, according to the disappearance model in the present invention and the casting manufacturing method using the disappearance model, the quality of the cast casting can be improved while facilitating the sanding operation when the disappearance model is embedded in the sand mold ( It is possible to provide a technique for producing a disappearance model and a casting for improving the casting quality.

BRIEF DESCRIPTION OF THE DRAWINGS It is the schematic which showed the whole structure of the vanishing model formed when casting a press die by the full mold method based on one Example of this invention, (a) is a top view of this vanishing model, (B) is a side view of the disappearance model viewed from an arrow X in the plan view. It is the figure which showed the deformation | transformation amount of each press die at the time of adding a load, (a) showed the deformation | transformation amount of the site | part corresponded to the housing part of the press die cast by the vanishing model in a present Example. The perspective view and (b) are the perspective views which showed the deformation | transformation amount of the site | part corresponded to the housing part of the press die cast by the conventional vanishing model. The side view which showed the state of the disappearance model at the time of pouring work. In the conventional press metal mold | die, it is the schematic which showed the whole structure of the vanishing model formed when casting by a full mold method, (a) is a top view of this vanishing model, (b) is this plane The side view of this disappearance model seen from arrow Y in a figure. The side view which showed the state of the conventional vanishing model at the time of pouring work.

  Next, embodiments of the invention will be described.

[Disappearance model 1]
First, the overall configuration of the disappearance model 1 embodying the present invention will be described with reference to FIGS. 1 and 2.
Here, for the sake of convenience, the following description will be made assuming that the direction of the arrow A in FIG. Moreover, in the side view of FIG.1 (b), the up-down direction on drawing is prescribed | regulated as the up-down direction of the vanishing model 1, and is demonstrated.
In the following description, in the casting cast by the full mold method, the configuration of the vanishing model 1 formed when casting is described by taking a press die as an example. The manufacturing method is not limited to this.
That is, the manufacturing method of the disappearance model and casting in the present invention is received during use while having a complicated shape such as a press die, a frame for welding equipment, a surface plate for an accuracy measuring jig, and the like. It can be widely applied to parts that require high rigidity against external force (load).

The disappearance model 1 is mainly made of polystyrene foam and is imitated according to the shape of the casting to be cast.
Here, examples of the casting to be cast include castings that have a complicated shape and require high rigidity against an external force (load) received during use, such as a press die.

The press mold is provided in a known press machine (not shown), and is a mold for subjecting a sheet-like workpiece to press processing such as drawing, bending, or shearing.
That is, in the press machine, the press die is assembled to one of a bolster that is fixedly held and a slide that is movable above and below the bolster, and the other is a press die. A corresponding mold having a corresponding relationship with the mold is assembled separately.
Then, by disposing a sheet-like workpiece between the press die and the corresponding die and moving the slide downward, the workpiece is made of the press die and the corresponding die. It is clamped (pressed) by a mold and pressed.

The press mold is configured to include a first part that directly receives a load from the outside during press processing, a second part that is provided to hold the first part, and the like.
Therefore, the disappearance model 1 is configured to include a functional unit 2 (a portion indicated by shading in FIG. 1) corresponding to the first part, a housing part 3 corresponding to the second part, and the like. Is done.

First, the function unit 2 will be described.
The functional part 2 is formed of a foamed polystyrene which is a member that is burned and disappeared by a molten metal 64 (see FIG. 3) for casting a press die, and is provided in a plurality of press parts 21. It is comprised by the to-be-inserted part 22 * 22 and the to-be-contacted part 23 * 23.

The press unit 21 is a portion of the press die to be cast, which is in contact with the workpiece when the workpiece is pressed using the press die (hereinafter referred to as a press die). Such a portion is described as “transfer press part”).
That is, a shape conforming to the formation surface of the transfer press portion is formed on the side surface portion (the upper surface portion in FIG. 1B) on one side of the press portion 21.

  The forming surface is a portion for the press die to press the workpiece. For example, when the press die is used to draw the workpiece, the forming surface is the workpiece. It is shaped into a shape that matches the shape to be transferred.

The plurality of press portions 21, 21... Having such a shape are respectively disposed at predetermined positions while a portion corresponding to the formation surface is directed upward.
And these press parts 21 * 21 ... are fixed to the housing | casing part 3 mentioned later in the lower side part (lower surface part in FIG.1 (b)) facing the site | part corresponded to the said formation surface.

  When the workpiece is pressed using the cast press mold, the transfer press portion of the press mold is pressed against the workpiece through the formation surface with high pressure, and the transfer press The part is directly subjected to a high-pressure compression load by the workpiece.

  The inserted portion 22 is a portion into which a guide pin or the like (not shown) that restricts the position of the press die in the horizontal direction is inserted when the workpiece is pressed using a cast press die. (Hereinafter, such a portion in the press mold is referred to as a “transfer insertion portion”).

  Here, the corresponding mold having the corresponding relationship with the press mold described above is provided with a round bar-shaped guide pin or the like extending toward the press mold, and the corresponding mold is in relation to the press mold. By being relatively close to and away from each other, the guide pins follow the corresponding die and are close to and away from the press die.

  On the other hand, the transfer insertion portion of the press die is perforated with a through hole having an inner diameter that is approximately the same as the outer diameter of the guide pin, and the transfer insertion portion is coaxial with the guide pin. It is arrange | positioned at a press metal mold | die so that it may be located in.

When the corresponding mold is moved to the vicinity of the press mold, the guide pin is inserted into the through hole of the transfer insertion portion.
At this time, when the position of the press mold in the horizontal direction is shifted with respect to the corresponding mold, the press mold is restored to the normal position while the guide pin is inserted into the through hole. The inner peripheral surface of the through-hole is pressed.

A plurality (two in the present embodiment) of inserted portions 22 and 22 of the disappearance model 1 are formed in accordance with the shape of the transfer inserted portion of the press die.
The inserted portions 22 and 22 are punched in accordance with the through holes of the transfer inserted portion, and the plurality of press portions 21 are viewed in a plan view with the axial center direction of the through holes 22a and 22a directed vertically. -It arrange | positions facing each other on both sides of 21 ....

As described above, when a workpiece is pressed using a cast press die, the guide pin is positioned when the position of the press die in the horizontal direction is deviated from the corresponding die. The inner peripheral surface of the through hole in the transfer insert portion of the press mold is pressed with high pressure by the outer peripheral surface.
Therefore, the transfer insertion portion of the press die is directly subjected to a high-pressure compression load by the guide pin.

  The contacted portion 23 abuts a contact stopper (not shown) that regulates the position of the press die in the vertical direction when the workpiece is pressed using a cast press die. (Hereinafter, such a portion in the press mold is referred to as a “transfer contact portion”).

  Here, the corresponding mold corresponding to the above-described press mold is provided with a contact stopper or the like protruding toward the press mold, and the corresponding mold is relative to the press mold. By approaching and separating from each other, the contact stopper follows the corresponding mold and is separated from and pressed by the press mold.

  Then, when the corresponding mold moves to the vicinity of the press mold, and the corresponding mold and the press mold are clamped, the protruding end surface of the contact stopper is the upper end surface of the transfer contact portion. The relative positions of the corresponding mold and the press mold in the vertical direction are restricted.

A plurality (two in this embodiment) of the contacted portions 23 and 23 of the disappearance model 1 are formed in accordance with the shape of the transfer contacted portion of the press die.
The abutted portions 23 and 23 are disposed to face each other with the above-described press portions 21.

  Note that when the workpiece is pressed using the cast press die, the upper surface portion of the transfer contact portion is pressed with a high pressure by the protruding end surface of the contact stopper, so that the transfer The contacted portion directly receives a high-pressure compressive load by the contact stopper.

As described above, the functional part 2 of the disappearance model 1 in this embodiment includes a plurality of press parts 21, 21..., Or inserted parts 22, 22 and contacted parts 23, 23 provided in pairs. Although configured, the present invention is not limited to this.
In other words, depending on the configuration of the press mold to be cast, there is no transfer insertion part or transfer contact part (that is, the transfer insertion part or transfer contact part is not a press mold or a corresponding mold. (It may be provided on a bolster or a slide that is fixedly held).
In the disappearance model imitated in order to cast such a press die, a functional part is constituted only by a plurality of press parts.

Next, the housing part 3 will be described.
The casing 3 is composed of a plurality of rod-shaped members 31, 31... And a plurality of connecting members 32, 32.

The rod-shaped member 31 is a member that forms the framework of the casing 3, and is configured by a hollow member that is burned and disappeared by the molten metal 64 that casts the press mold.
Here, the material of the rod-shaped member 31 is not particularly limited as long as it is a material combusted by the molten metal 64, such as foamed polystyrene, wood, or bamboo. For example, in the sand mold to form a runner or a weir during casting. It can be constituted by a commercially available paper pipe to be embedded.
That is, by constructing the bar-shaped member 31 with such a commercially available paper pipe, the versatility of the casing 3 is increased, the manufacturing cost of the disappearance model 1 as a whole can be reduced, and the inside of the sand mold at the time of casting is reduced. The molten metal flowing state is also improved, and the casting quality can be improved.

Further, the rod-shaped member 31 is not only formed to extend in a columnar shape, but may be formed to extend in a conical shape, for example, and the cross-sectional shape of the rod-shaped member 31 is a polygon such as a triangle or a quadrangle. Alternatively, it can be configured by any shape such as an elliptical shape, but can be configured by a cylindrical shape as shown in this embodiment.
That is, by forming the rod-shaped member 31 with a cylindrical member having a circular cross-sectional view, the casting sand 63 to be thrown in from above the mold 62 at the time of burying the disappearance model 1 described later (see FIG. 3), On the way, it falls without being stacked on the rod-shaped member 31, reliably passes through the housing 3, and reaches the bottom in the mold 62.
Therefore, the foundry sand 63 is uniformly filled in the mold 62 without being unevenly distributed, so that the quality of the sand mold 60 can be improved and the casting quality can be improved.

The connecting member 32 is a member for connecting a plurality of rod-shaped members 31, 31..., And is burned by a molten metal 64 that casts a press die, like the rod-shaped members 31, 31. Consists of disappearing members.
Here, the material of the connecting member 31 is not particularly limited as long as it is a material combusted by the molten metal 64 such as a paper material. For example, the connecting member 31 may be made of foamed polystyrene to reduce the weight of the disappearance model 1 as a whole. .

The shape of the connecting member 32 is not particularly limited, such as a polyhedron or a sphere, but a plurality of holes having an inner diameter dimension substantially the same as the outer diameter dimension of the rod-shaped member 31 are formed on the outer peripheral surface thereof.
In addition, about the inside of the connection member 32, it is good also as a solid structure in order to achieve rigidity, and it is good also as a hollow structure in order to achieve weight reduction.

  And connecting member 32 is arranged between rod-like members 31 and 31 which adjoin mutually, and these rod-like members 31 and 31 are inserted in the hole of connecting member 32, respectively, and these rod-like members are inserted. The members 31 and 31 are connected.

  A plurality of rod-shaped members 31, 31... And connecting members 32, 32,... Having such a shape are used to form a polygonal frame (triangular in this embodiment) as a minimum unit. And the frame part 3 is comprised by combining several such frame structures of the minimum unit.

That is, twelve rod-shaped members 31a, 31a,... Arranged along the sides of the rectangular parallelepiped, and eight connecting members 32a, 32a,. In the assembled frame structure (hereinafter referred to as “cuboid structure”), six side members 31b, 31b,.
That is, the rectangular parallelepiped structure is a tetrahedral structure constituted by four connecting members 32a, 32a,..., Three rod members 31a, 31a, 31a, and three rod members 31b, 31b, 31b. It is constituted by combining a plurality. Further, the tetrahedral structure is a triangular smallest unit first composed of three connecting members 32a, 32a and 32a, two rod-shaped members 31a and 31a, and one rod-shaped member 31b. It is configured by combining a plurality of frame structures Z1, Z1,.

And the center part of the frame part 3 is formed by combining multiple rectangular parallelepiped structures which consist of such a structure.
In other words, the central part of the housing part 3 is formed by combining a plurality of triangular-shaped minimum unit first framework structures Z1, Z1,.

On the other hand, a plurality of connecting members 32b, 32b,... Are provided on the outer peripheral portion of the housing portion 3, and the connecting members 32b and 32b that are close to each other in the vertical direction in a side view are disposed in the upright direction. It is connected by a bar member 31c.
Further, the connecting members 32c, 32c,... Positioned in the vicinity of the connecting members 32b, 32b,... Extend in the horizontal direction and the rod-shaped members 31d, 31d,. It is connected by rod-like members 31e, 31e,.

  As a result, in the outer peripheral part of the housing part 3, the triangular frame structure Z2 as a minimum unit composed of the three rod-shaped members 31c, 31d, 31d and the three connecting members 32b, 32b, 32c, and three A triangular frame structure Z3 is formed as a minimum unit composed of the rod-shaped members 31a, 31d, 31e and the three connecting members 32b, 32c, 31c, and a plurality of these frame structures Z2,. Thus, the outer peripheral portion of the housing portion 3 is configured.

As described above, the housing portion 3 includes a plurality (three in the present embodiment) of the rod-shaped members 31a, 31a, and 31b (the rod-shaped members 31c, 31d, and 31d, or the rod-shaped members 31a, 31d, and 31e) and the rod-shaped members. A plurality of connecting members 32a, 32a, and 32a (connecting members) for connecting 31a, 31a, and 31b (bar-shaped members 31c, 31d, and 31d, or bar-shaped members 31a, 31d, and 31e) into a polygonal shape (triangular shape in this embodiment) 32b, 32b, and 32c, or the connecting members 32b, 32c, and 32c), and a triangular frame structure is configured as a minimum unit.
That is, the housing 3 is configured by combining a plurality of triangular frame structures Z1,..., Z2,... Z3, which are minimum units, and these rod-shaped members 31a, 31a, 31b (bar-shaped members 31c, 31d,. 31d, or a rod-shaped member 31a, 31d, 31e) is formed as an aggregate of polygonal shapes (triangular in this embodiment) as a rectangular solid as a whole.

Further, in the skeleton on the upper surface side of the housing portion 3, a plurality of press portions 21, 21... Are disposed at predetermined positions in the central portion in plan view, and these press portions 21, 21,. The lower surface is fixed to the upper surface of the connecting members 32a, 32a... (Or the connecting members 32c, 32c...) With an adhesive.
In other words, the press parts 21, 21... Are connected to the rod-shaped members 31 a, 31 a, etc. of the housing part 3 via the connection members 32 a, 32 a, (or the connection members 32 c, 32 c). And is held by the housing 3.

  Further, in plan view, the inserted portions 22 and 22 and the abutted portions 23 and 23 are respectively arranged diagonally at the four corners of the housing portion 3.

A plurality of rod-shaped members 31f, 31f... Disposed along the outer peripheral portion of the housing portion 3 are inserted into the inserted portions 22 and 22 and the abutted portions 23 and 23, and the rod-shaped members are inserted. The inserted portions 22 and 22 and the abutted portions 23 and 23 are connected to the plurality of connecting members 32b, 32b,.・ Concatenated with
That is, the inserted portions 22 and 22 and the contacted portions 23 and 23 are connected to the housing portion 3 via the plurality of rod-shaped members 31f, 31f, and are held by the housing portion 3.

It is possible to freely change the number, the number, the shape, or the like of the plurality of rod-shaped members 31, 31... And the connecting members 32, 32.
Therefore, the framework of the housing part 3 is used in the size and arrangement position of the press parts 21, 21..., The inserted parts 22, 22, the abutted parts 23, 23, or the press mold to be cast. It can be freely configured depending on places where high rigidity is required with respect to external force (load) that is sometimes received.
Therefore, the disappearance model 1 has a complicated shape and can cope with a wide range of castings such as press dies that require high rigidity with respect to external force (load) received during use. It can be done.

Here, the press molds 50 and 150 are taken as examples of castings casted by the vanishing model 1 in the present embodiment and the conventional vanishing model 100 (see FIG. 4), and each of the press molds 50 and 150 is taken as an example. A comparison of the rigidity of the portions corresponding to the housing portions 3 and 102 (hereinafter referred to as “transfer housing portion 51” and “transfer housing portion 151”, respectively) will be described with reference to FIG.
Note that the configuration of each of the transfer casing portions 51 and 151 is described with a configuration slightly different from the configuration of the casing portions 3 and 102 in order to simplify the description.

  First, as shown in the upper diagram of FIG. 2B, the transfer casing portion 151 of the press die 150 cast by the conventional disappearance model 100 is formed by flat plate portions 102a, 102a,. .. And a transfer upper surface portion 153, which are parts corresponding to the upper surface portion 102b.

  That is, the skeleton of the transfer casing portion 151 has a transfer upper surface portion 153 disposed in the horizontal direction and a lower surface of the transfer upper surface portion 153 in a direction perpendicular to the transfer upper surface portion 153 (with respect to the transfer upper surface portion 153. (A direction orthogonal to each other) and a plurality of transfer plane portions 152, 152,. Composed.

  When a load in the vertical direction (load P in FIG. 2B) is applied to the entire transfer casing portion 151 having such a configuration, a transfer plane disposed along the vertical direction of the transfer casing portion 151. A compressive load acts on the parts 152, 152. At this time, since these transfer plane portions 152, 152... Are connected to each other by the transfer upper surface portion 153, the compressive load is dispersed and weakened to the plurality of transfer plane portions 152, 152. It is done.

As a result, as shown in the lower diagram of FIG. 2B, the state before the load P is applied (the transfer casing 151A in FIG. 2B) and the state after the load P is applied (FIG. 2). When compared with the transfer housing portion 151B) in (b), the transfer upper surface portion 153 is slightly bent downward, but the transfer plane portions 152, 152. It can be seen that the amount of deformation of the entire transfer casing 151 when the load P is applied is a slight amount.
Therefore, it can be seen that in the press mold 150 cast by the conventional vanishing model 100, the transfer casing 151 has high rigidity.

The slight buckling that occurs in each transfer plane portion 152 forms a slight bend at the lower end of the transfer plane portion 152.
As a result, the distance between the adjacent transfer plane portions 152 and 152 (dimension B1 in FIG. 2B) is slightly deformed at the lower end portion of the transfer casing portion 151B.

  On the other hand, as shown in the upper diagram of FIG. 2 (a), the transfer casing portion 51 of the press die 50 cast by the disappearance model 1 of the present embodiment is a rod-shaped member 31 of the disappearance model 1. And a plurality of transfer rod-shaped portions 52, 52,... And transfer connection portions 53, 53,.

  That is, the skeleton of the transfer casing portion 51 includes a triangular frame structure as a minimum unit by the three transfer rod-like portions 52, 52, 52 and the three transfer connecting portions 53, 53, 53. A tetrahedron structure formed by combining a plurality of minimum unit frame structures is further combined to form a rectangular parallelepiped structure, and a plurality of the rectangular parallelepiped structures are combined on a horizontal plane.

When a load in the vertical direction (load P in FIG. 2A) is applied to the entire transfer casing portion 51 having such a configuration, a transfer rod shape disposed along the vertical direction of the transfer casing portion 51. A compressive load acts on the portions 52a, 52a, etc., but the transfer rod-shaped portions 52b, 52b,... Arranged along the horizontal direction of the transfer casing 51, and the transfer arranged on both upper and lower side surfaces. The rod-shaped portions 52c, 52c,... Are not directly affected by the load P.
In addition, the load P that is dispersed and weakened is applied to the transfer rod-like portions 52d, 52d,. Acts as a compressive load.

  For this reason, each tetrahedron structure constituting the skeleton of the transfer casing 51 includes the transfer rod-like portions 52b, 52b,..., The transfer rod-like portions 52c, 52c,. By 52d, 52d, etc., the shape before the load P is applied will be kept strong so as to maintain the shape.

As a result, as shown in the lower diagram of FIG. 2A, the state before the load P is applied (the transfer housing portion 51A in FIG. 2A) and the state after the load P is applied (FIG. 2). Comparing with the transfer housing part 51B) in (a), it can be seen that the deformation amount of the transfer housing part 51 as a whole when the load P is applied is a slight amount.
In addition, it can be seen that the distance between the adjacent transfer connecting portions 53 and 53 (dimension B2 in FIG. 2A) is not substantially deformed at the lower end portion of the transfer casing portion 51B.
Therefore, also in the press die 50 cast by the disappearance model 1 of the present embodiment, it can be seen that the transfer casing portion 51 has higher rigidity than the press die 150 described above.

As described above, in the disappearance model 1 in the present embodiment, for the functional part 2 corresponding to the first part that directly receives a load from the outside in a casting such as a press die, a cutting machine or the like is used. The material made of Styrofoam is precisely cut and shaped.
Further, in the disappearance model 1 in the present embodiment, the casing portion 3 corresponding to the second portion for holding the first portion in the press die (casting) has a plurality of rod shapes made of, for example, a paper pipe or the like. It is supposed that it is configured as an aggregate (skeleton structure) of a minimum unit frame composed of members 31, 31... And a plurality of connecting members 32, 32.

  By having such a configuration, the vanishing model 1 has a higher rigidity than the vanishing model 100 (see FIG. 4) having the casing portion 102 having a rectangular box structure as in the prior art. It is possible to reduce the overall weight while maintaining it, and it is easy for the operator to handle, and the work of embedding the lost model 1 in the foundry sand can be improved.

Moreover, by having such a structure, the structure of the housing | casing part 3 of the vanishing model 1 is simplified, and the amount of the mold agent applied to the vanishing model 1 can also be reduced.
As a result, in the disappearance model 1, there is no fear that casting quality deteriorates due to distortion occurring in part of the disappearance model 100 due to the weight of the coating agent as in the conventional disappearance model 100.

  Moreover, by having such a structure, the vanishing model 1 can significantly reduce the material portion of the expanded polystyrene compared to the conventional vanishing model 100, and at the time of casting the molten metal 64 (see FIG. 3). The amount of gas generated in the sand mold 60, which will be described later, is also greatly reduced, and the casting quality can be improved.

Furthermore, by having such a configuration, each constituent element occupying the entire disappearance model 1 (more specifically, the press portion 21, the inserted portion 22, the abutted portion 23, and the casing constituting the functional portion 2) The size of the rod-shaped member 31 and the connecting member 32) constituting the portion 3 is reduced, and the amount of contraction when the molten metal 64 poured is cooled is also reduced.
Therefore, it is not necessary to form the vanishing model 1 in large size in anticipation of the contraction amount, and it is easy for the operator to handle, and the sanding operation of the vanishing model 1 described later can be improved easily.

  Moreover, at the time of manufacture of the vanishing model 1 in the present embodiment, the press parts 21, 21..., The inserted parts 22, 22 and the abutted parts 23, 23 constituting the functional part 2 are individually modeled. In addition, the press portions 21, 21..., The inserted portions 22 and 22, and the abutted portions 23 and 23 are each composed of small parts.

  Therefore, these press parts 21, 21..., Inserted parts 22, 22 and abutted parts 23, 23 can be formed integrally by conventional processing equipment without providing large processing equipment. Can do.

Therefore, there is no need to laminate and bond these shaped foamed polystyrenes in order after shaping each of a plurality of plate-like foamed polystyrenes like a conventional disappearance model, and the amount of adhesive used can be reduced. Is.
In addition, as in the conventional disappearance model 100 (see FIG. 4), when stacking a plurality of these foamed polystyrenes, misalignment of the foamed polystyrene does not occur, and casting quality is deteriorated. There is nothing wrong.

[Casting method of casting using vanishing model 1]
Next, taking a press die as an example of a casting cast using the vanishing model 1, a method for casting the press die will be described with reference to FIGS.
In the following description, for the sake of convenience, the direction of the arrow A in FIGS.
3 and 5, the vertical direction on the drawing is defined as the vertical direction of the sand molds 60 and 160 used in the casting method, which will be described below.

As shown in FIG. 3, in the casting method of the press die (casting) using the disappearance model 1, first, the disappearance model 1 preliminarily shaped according to the shape of the press die (casting) to be cast, A paper pipe 61 for forming a runner and a weir is fixed.
The paper pipe 61 is composed of, for example, two first paper pipes 61a and 61a and second paper pipes 61b and 61b having large and small outer diameters.

  The first paper pipe 61a has a larger outer diameter than the second paper pipe 61b, and is disposed in the disappearance model 1 as a part that forms a runner when pouring the molten metal 64 into the sand mold 60. .

  More specifically, the first paper pipes 61a and 61a are connected to each other in a direction perpendicular to each other, and one of the first paper pipes 61a is provided on the side where the press portions 21 and 21. In FIG. 1, the other first paper pipe 61a is positioned in the vicinity of the disappearance model 1 so as to be positioned in the vicinity of the disappearance model 1 (on the lower side of the disappearance model 1 in FIG. 1). It is arrange | positioned so that it may extend.

The second paper pipe 61b has a smaller outer diameter than the first paper pipe 61a, and is disposed in the disappearance model 1 as a portion that forms a weir when the molten metal 64 is poured into the sand mold 60.
More specifically, the second paper pipes 61 b and 61 b are disposed between the one first paper pipe 61 a described above and the disappearance model 1.

  In each second paper pipe 61b, one end is connected to one of the first paper pipes 61a described above, and the other end is connected to any one connecting member 32d at the four corners of the disappearance model 1.

  The paper pipes 61 and 61 having such a structure are provided at two locations with respect to the integral vanishing model 1, and all the connecting members 32d, 32d, 32d, and 32d at the four corners of the vanishing model 1 are connected to the second paper pipe 61b. -It communicates with the first paper pipes 61a, 61a via 61b, 61b, 61b.

  On the other hand, as shown in FIG. 5, also in the manufacturing method of the press die using the conventional disappearance model 100, first, the runner is added to the disappearance model 100 preliminarily shaped according to the shape of the press die to be cast. The paper pipe 161 for forming the dam and the weir is fixed, but the configuration of the paper pipe 161 is different from the paper pipe 61 fixed to the disappearance model 1.

That is, the configuration of the first paper pipes 161a and 161a arranged in the disappearance model 100 as a part that forms a runner is the same as the first paper pipes 61a and 61a of the paper pipe 61 described above.
However, the configuration of the second paper pipes 161b, 161b,... Arranged in the disappearance model 100 as a portion forming the weir is that a plurality of the second paper pipes 61b, 61b of the paper pipe 61 described above are provided. And different.

  The plurality of second paper pipes 161b, 161b,... Are connected to one first paper pipe 161a at one end, and the press part constituting the functional unit 101 of the disappearance model 100 at the other end. 111, 111..., The inserted portion 112, and the contacted portion 113.

In this way, the configuration of the paper pipe 61 fixed to the disappearance model 1 in this embodiment is different from that of the paper pipe 161 fixed to the conventional disappearance model 100 for the following reason.
That is, in the conventional disappearance model 100, since the entire shape is formed using only polystyrene foam, the amount of gas generated when pouring molten metal 164 becomes large. Therefore, in the disappearance model 100, the molten metal 164 is provided with a plurality of second paper pipes 161b, 161b... So that the molten metal 164 is not hindered by the gas and the casting quality is not deteriorated. Multiple roads to the disappearance model 100 were secured.

  On the other hand, in the disappearance model 1 in the present embodiment, only the press part 21, the inserted part 22, the abutted part 23, and the connecting member 32 that constitute the housing part 3 that form the functional part 2 are formed of foamed polystyrene. However, the rod-like member 31 occupying most of the housing part 3 is constituted by a paper pipe.

Therefore, the amount of polystyrene foam used for the disappearance model 1 is greatly reduced, and the amount of gas generated when pouring the molten metal 64 is significantly reduced as compared with the conventional disappearance model 100.
Therefore, in the disappearance model 1, it is not necessary to provide a plurality of second paper pipes 61 b, 61 b... So that the hot metal flow of the molten metal 64 is not hindered by the gas. It is sufficient to provide the second paper pipes 61b, 61b, 61b, and 61b on the connecting members 32d, 32d, 32d, and 32d.
In other words, with such a configuration, the molten metal 64 that has reached the connecting members 32 d, 32 d, 32 d, and 32 d then passes through the rod-shaped member 31 to the entire disappearance model 1.

As described above, in the disappearance model 1, it is possible to reduce the number of second paper pipes 61b and 61b disposed in the disappearance model 1 as a portion that forms a weir, as compared with the conventional disappearance model 100. The configuration of the pipe 61 is relatively simple.
As a result, the cost of the sand mold 60 as a whole can be reduced, and the paper pipe 61 is easy to handle for the operator, and the work of fixing the paper pipe 61 to the disappearance model 1 can be improved. It can be done.

When the paper pipe 61 is fixed to the disappearing model 1, the modeling work of the sand mold 60 is started.
The modeling work of the sand mold 60 is performed by embedding the disappearance model 1 in the foundry sand 63 in a mold 62 having a box structure with an upper surface opened.

  More specifically, the disappearance model 1 is disposed in a mold 62 in which a small amount of foundry sand 63 is previously placed, with the side where the press portions 21, 21. Further, the casting sand 63 is put into the mold 62 from above and filled, whereby the disappearance model 1 is embedded in the casting sand 63 and the sand mold 60 is formed.

  On the other hand, as shown in FIG. 5, also in the conventional method for manufacturing a press mold using the disappearance model 100, when the paper pipe 161 is fixed to the disappearance model 100, the modeling work of the sand mold 160 is started.

  Here, the modeling work of the sand mold 160 is performed in two stages: sand filling work from the back side (the lower surface side in FIG. 4) of the disappearance model 100 and sand filling work from the front surface side (upper surface side in FIG. 4). .

  That is, first, in the mold 162, the disappearance model 100 is disposed with the plurality of press portions 111, 111,... Facing upward, and the surfaces of these press portions 111, 111,. Sanding work is performed on details.

  After that, the disappearance model 100 is disposed again in the mold 162 with its up and down direction reversed (that is, the disappearance model 100 is disposed in the mold 162 so that the press portion 111 faces downward). The sanding operation is performed on the plurality of space portions 121, 121,.

  Such sanding work is performed by pressing the foundry sand 163 against the press part 111 and the space part 121 with a fingertip while the worker maintains an unnatural posture consisting of a heel and a stomach.

  Depending on the shape of the press part 111 and the space part 121, the quality of the sanding work depends on the maturity level and skill of the operator who performs the sanding work, such as cans and tips. It was.

  As described above, in the conventional disappearance model 100, the through-holes 102d, 102d, and 102d are partially formed for the purpose of passing the wiring or reducing the weight due to the configuration of the press die (casting) to be cast. .. (see FIG. 4) may be formed, but most of the housing 102 is constituted by a box structure composed of an upper surface 102b and a plurality of flat plates 102a, 102a, etc. In order to attach the foundry sand 163 to the details around the disappearance model 100, sanding work in two stages from both the front and back sides was necessary.

On the other hand, in the disappearance model 1 in the present embodiment, the housing portion 3 is configured by a skeleton structure including a plurality of rod-shaped members 31, 31... And connecting members 32, 32.
Therefore, the foundry sand 63 thrown in from above the mold 62 passes through the casing portion 3 and easily reaches the bottom of the mold 62, and then the foundry sand 63 filled in the mold 62 is obtained. Will be hardened without gaps by its own weight.

  Therefore, in the modeling work of the sand mold 60 using the disappearance model 1 in this embodiment, compared to the modeling work of the sand mold 160 using the conventional disappearance model 100, the back side of the disappearance model 100 (the lower side in FIG. 1). Therefore, the modeling work can be easily improved.

  Further, in the sand filling work of the disappearing model 1, the operator presses the foundry sand 163 with the fingertip while maintaining an unnatural posture consisting of a crawling or a hungry state like the sand sanding work of the conventional disappearing model 100. No such work is required, and it is only necessary to throw in the foundry sand 63 from above the mold 62 in which the vanishing model 1 is installed.

Therefore, in the modeling work of the sand mold 60 using the disappearing model 1 in the present embodiment, the operator can perform the sanding work of the disappearing model 1 by a natural standing posture, and the modeling work is improved to be easy. can do.
In addition, uniform casting quality can be ensured without being influenced by the maturity level of the skill and skill of the operator who performs the sanding work.
Furthermore, uniform casting quality can be ensured without deforming the detailed shape of the vanishing model 1 or causing bending by the pressing force of the fingertip of the operator.

The vanishing model 1 is arranged in the mold 62 with the side on which the press portions 21, 21... Are arranged facing downward for the following reason.
That is, when the molten metal 64 is poured into the sand mold 60, the molten metal 64 in the sand mold 60 is easily hindered by the resistance of the gas generated from the disappearance model 1, and the downstream side of the molten metal flow (see FIG. 3 may cause a reduction in casting quality.
Therefore, the vanishing model 1 is provided with press portions 21, 21... That require high casting quality on the upstream side of the molten metal flow (upper side in the sand mold 60 in FIG. 3). In this case, such a decrease in casting quality is avoided as much as possible with respect to 21, 21.

When the foundry sand 63 is filled into the mold 62, the upper surface of the mold 62 is closed by the lid member 65. At this time, the upper end portion of the other first paper pipe 61 a described above penetrates the lid member 65 and communicates with the spout 66 provided on the upper surface portion of the lid member 65.
Thereafter, the molten metal 64 is poured into the spout 66 and pouring of the molten metal 64 into the sand mold 60 is started.

The molten metal 64 poured into the spout 66 passes through the first paper pipe 61a and the second paper pipe 61b in this order to reach the disappearance model 1.
The molten metal 64 that has reached the vanishing model 1 first burns the connecting members 32b, 32b, 32b, and 32b at the four corners of the vanishing model 1. As a result, the connecting members 32b, 32b, 32b, and 32b disappear, and the portions where the connecting members 32b, 32b, 32b, and 32b existed are filled with the molten metal 64.
Thereafter, the molten metal 64 reaches the entire disappearance model 1 through the insides of the plurality of rod-shaped members 31. When the molten metal 64 is filled into the disappearance model 1 through the plurality of rod-shaped members 31, 31..., The rod-shaped members 31, 31.
In this way, the molten metal 64 is filled in the sand mold 60 in place of the disappearance model 1 (the functional part 2 and the housing part 3).
In this embodiment, the rod-shaped members 31, 31... Are constituted by hollow pipes. However, the rod-shaped members 31, 31. Therefore, it can be configured by a solid bar-like member.

  Thereafter, the molten metal 64 is cooled together with the sand mold 60, and a press mold (casting) conforming to the shape of the disappearance model 1 is cast.

  As described above, the vanishing model 1 in the present embodiment is a vanishing model 1 for casting a casting such as a press mold, for example, and the vanishing model 1 directly receives a load from the outside in the casting. A functional part 2 corresponding to one part, and a casing part 3 corresponding to a second part for holding the first part in the casting. The casing part 3 includes a plurality of rod-shaped members 31. ... And a plurality of connecting members 32, 32... That connect these rod-shaped members 31, 31..., And a polygonal shape formed by these rod-shaped members 31. The functional unit 2 is coupled to the housing unit 3 through the coupling members 32, 32, and the functional unit 2, the coupling members 32, 32, and rods. The members 31, 31. Is set to be configured by members to disappear is burned by molten metal 64.

  The mold manufacturing method according to the present embodiment is a casting manufacturing method such as a press mold that is cast using the disappearance model 1, and the disappearance model 1 applies a load from the outside to the casting. A functional part 2 corresponding to the first part directly received, and a casing part 3 corresponding to the second part for holding the first part in the casting, the casing part 3 comprising a plurality of parts The rod-shaped members 31, 31 ... are connected to each other by connecting members 32, 32 ... to form a polygonal aggregate formed by these rod-shaped members. .. Are connected to the housing 3 via 32..., And the functional part 2, the connecting members 32, 32... And the rod-shaped members 31, 31. Is formed of a member that disappears, 1 is embedded in a sand mold 60, a molten metal 64 is poured into the sand mold 60, and the casting is cast while replacing the vanishing model 1 with the molten metal 64 poured into the sand mold 60. It is said.

  By having such a configuration, according to the disappearance model 1 in this embodiment and the manufacturing method of the casting cast using the disappearance model 1, the sand filling operation when the disappearance model 1 is embedded in the sand mold 60. It is possible to provide the technology of the disappearance model 1 and the casting manufacturing method for improving the quality (casting quality) of the cast casting while facilitating the process.

  That is, in the disappearance model 1 in the present embodiment, for example, the casing portion 3 corresponding to the second portion for holding the first portion in the press die as an example of such a casting has a plurality of rod shapes. It is supposed to be configured as an aggregate (skeleton structure) of the minimum unit frame constituted by the members 31, 31... And the connecting members 32, 32.

  Therefore, the foundry sand 63 thrown in from above the mold 62 passes through the casing portion 3 and easily reaches the bottom of the mold 62, and then the foundry sand 63 filled in the mold 62 is obtained. Will be hardened without gaps by its own weight.

  Therefore, in the modeling work of the sand mold 60 using the disappearance model 1 in this embodiment, compared to the modeling work of the sand mold 160 using the conventional disappearance model 100, the back side of the disappearance model 100 (the lower side in FIG. 1). Therefore, it is possible to improve the sanding work easily.

Further, in the sand filling work of the disappearing model 1, the operator presses the foundry sand 163 with the fingertip while maintaining an unnatural posture consisting of a crawling or a hungry state like the sand sanding work of the conventional disappearing model 100. No such work is required, and it is only necessary to throw in the foundry sand 63 from above the mold 62 in which the vanishing model 1 is installed.
Therefore, uniform casting quality can be ensured without being influenced by the maturity level of the skill and skill of the operator who performs the sanding work.

  Moreover, in the manufacturing method of the disappearance model 1 and the casting in the present embodiment, the functional part 2 is formed by foamed polystyrene.

  By having such a configuration, the vanishing model 1 can greatly reduce the material portion of the expanded polystyrene compared to the conventional vanishing model 100, and the gas generated in the sand mold 60 when the molten metal 64 is cast. The amount of steel can be greatly reduced, and the casting quality can be improved.

  Moreover, in the vanishing model 1 and the casting manufacturing method in the present embodiment, the rod-shaped member 31 is a hollow member.

By having such a configuration, the molten metal 64 poured into the mold 60 passes through the rod-shaped member 31 and reliably reaches the entire disappearance model 1. In particular, if the rod-shaped member 31 is formed of a cylindrical member, the casting sand 63 thrown in from the upper side of the mold 62 falls without being stacked on the rod-shaped member 31 on the way, and reliably passes through the casing 3 to form the mold frame. It reaches the bottom of 62.
Therefore, the foundry sand 63 is uniformly filled in the mold 62 without being unevenly distributed, so that the quality of the sand mold 60 can be improved and the casting quality can be improved.

DESCRIPTION OF SYMBOLS 1 Disappearance model 2 Functional part 3 Housing part 31 Rod-shaped member 32 Connecting member 60 Sand mold 64 Molten metal

Claims (6)

A vanishing model for casting a casting,
The disappearance model is
A functional portion corresponding to a first portion that directly receives a load from the outside in the casting,
A housing portion corresponding to a second portion for holding the first portion in the casting,
With
The housing part is
A plurality of rod-shaped members;
A plurality of connecting members for connecting these rod-shaped members to each other;
And having
It is configured as a polygonal aggregate formed by these rod-shaped members,
The functional unit is
Connected to the housing through the connecting member,
The functional unit, the connecting member, and the rod-shaped member are
Consists of a member that burns and disappears by the molten metal that casts the casting,
The disappearance model characterized by that. The functional part is shaped by foamed polystyrene,
The disappearance model according to claim 1 characterized by things. The rod-shaped member is a hollow member,
The disappearance model according to claim 1 or 2, characterized by the above-mentioned. A method for manufacturing a casting that uses an disappearance model,
The disappearance model is
A functional portion corresponding to a first portion that directly receives a load from the outside in the casting,
A housing portion corresponding to a second portion for holding the first portion in the casting,
With
The housing part,
A plurality of rod-shaped members are connected to each other by a connecting member,
Configured as a polygonal aggregate formed by these rod-shaped members,
The functional unit is
Connected to the housing part via the connecting member,
The functional unit, the connecting member, and the rod-shaped member are
Consists of a member that burns and disappears by the molten metal that casts the casting,
Embedding the disappearance model in a sand mold, pouring molten metal into the sand mold, and casting the casting while replacing the disappearance model with the molten metal poured into the sand mold,
The manufacturing method of the casting characterized by the above-mentioned. The functional part is shaped by foamed polystyrene,
The method for producing a casting according to claim 4, wherein: The rod-shaped member is a hollow member,
The method for producing a casting according to claim 4 or 5, wherein:

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