Method for producing cast product, cast product production device, and mold

Abstract

A production method includes a preparation step of preparing a mold including a fixed mold and a movable mold, disposing a pipe in the mold such that an injection opening and a discharge opening are exposed outside from the mold, closing the mold, injecting an incompressible fluid into the injection opening to fill a third flow path of a main portion of the pipe with the incompressible fluid, filling a molding space formed by the movable mold and the fixed mold with a melted metal material, discharging the incompressible fluid in the third flow path from the discharge opening, and separating the movable mold from the fixed mold to open the mold and extracting a cast product having the incompressible fluid discharged from the third flow path.

Description

BACKGROUND OF THE INVENTION1. Field of the Invention

[0001] The present invention relates to methods for producing cast products, cast product production devices, and molds.2. Description of the Related Art

[0002] Conventionally, a method called “insert casting” is used for producing a cast product. For example, a cast product produced by the insert casting has a pipe, pre-produced separately from the cast product itself, incorporated thereto. In more detail, according to the insert casting, a pipe is preset in a mold for producing a cast product, and then a molten metal, produced by a metal material such as an aluminum alloy or the like being melted, is injected into the mold. As a result, a cast product having the pipe incorporated thereto is produced. An example of cast product having such a pipe incorporated thereto is a case of a driving motor or the like.

[0003] For example, Japanese Patent Application Publication No. 2020-124743 discloses a method for producing a cast product by which a smart core including a tubular pipe filled with a filling material is inserted into a mold having a cavity formed therein, a molten metal is injected into the cavity, and then the filling material is removed from the smart core.SUMMARY OF THE INVENTION

[0004] According to Japanese Patent Application Publication No. 2020-124743, the filling material in the tubular pipe is removed after the cast product having the smart core incorporated thereto is extracted from the mold. That is, after the cast product is taken out from the mold, the cast product needs to be set in a device for removing the filling material. This may undesirably extend the time to produce the cast product.

[0005] Example embodiments of the present invention provide methods for producing cast products and cast product production devices by each of which an incompressible fluid filling the pipe incorporated into the cast product is removed efficiently.

[0006] A method for producing a cast product according to an example embodiment of the present invention is a method for producing a cast product including a pipe including an injection opening into which an incompressible fluid is injectable, a discharge opening from which the incompressible fluid is dischargeable, and a flow path located between the injection opening and the discharge opening to allow the incompressible fluid to flow therethrough, and a metal material that is cast with the pipe disposed therein. The method includes preparing a mold including a fixed mold and a movable mold movable to approach, or to be separated from, the fixed mold, disposing the pipe in the mold such that the injection opening and the discharge opening are exposed outside from the mold, causing the movable mold to approach the fixed mold to close the mold, injecting the incompressible fluid into the injection opening to fill the flow path with the incompressible fluid, filling a molding space formed by the movable mold and the fixed mold with a melted metal material, discharging the incompressible fluid in the flow path from the discharge opening, and separating the movable mold from the fixed mold to open the mold and extracting the cast product having the incompressible fluid discharged from the flow path.

[0007] With the production method according to the present example embodiment of the present invention, the incompressible fluid is injected into the injection opening in a state where the pipe is disposed in the mold, and after the molding space is filled with the melted metal material, the incompressible fluid is discharged from the discharge opening in a state where the pipe is disposed in the mold. Thus, the incompressible fluid filling the flow path of the pipe is discharged from the discharge opening in a state where the cast product is present in the mold. Therefore, the cast product does not need to be set in a device for removing the incompressible fluid, and thus the time for producing the cast product may be shortened. In the case where the cast product is extracted from the mold in a state where the flow path of the pipe is filled with the incompressible fluid, there is an undesirable possibility that the incompressible fluid splatters outside through the injection opening or the discharge opening of the pipe. However, according to the above-described production method, the incompressible fluid has already been discharged when the cast product is extracted from the mold. Therefore, there is no possibility that the incompressible fluid splatters outside.

[0008] A cast product production device according to an example embodiment of the present invention includes a mold including a fixed mold and a movable mold movable to approach, or to be separated from, the fixed mold, the mold being configured such that in a state where a pipe including a first straight portion that includes an injection opening into which an incompressible fluid is injectable, a second straight portion that includes a discharge opening from the which incompressible fluid is dischargeable, and a main portion that is located between the first straight portion and the second straight portion and includes a flow path through which the incompressible fluid flows is in a molding space formed by the movable mold and the fixed mold, the injection opening and the discharge opening are exposed outside, and a fluid transporter attachable to the injection opening and the discharge opening of the pipe in the molding space, the fluid transporter injecting the incompressible fluid into the injection opening and discharging the incompressible fluid from the discharge opening.

[0009] With the cast product production device according to the present example embodiment of the present invention, the fluid transporter attached to the injection opening and the discharge opening of the pipe in the molding space injects the incompressible fluid into the injection opening and discharges the incompressible fluid from the discharge opening. Thus, the incompressible fluid may be discharged from the discharge opening of the pipe in a state where the pipe is disposed in the mold. Therefore, the cast product does not need to be set in a device for removing the incompressible fluid, and thus the time for producing the cast product may be shortened. In addition, the relative positions of the fluid transporter and the mold are not changed whether the incompressible fluid may be injected into the injection opening or discharged from the discharge opening. Therefore, the injection and the discharge of the incompressible fluid may be performed with high precision.

[0010] A mold according to an example embodiment of the present invention includes a fixed mold, and a movable mold movable to approach, or to be separated from, the fixed mold. The mold is configured such that a pipe is in a molding space formed by the movable mold and the fixed mold, the pipe including a first straight portion that includes an injection opening into which an incompressible fluid is injectable, a second straight portion that includes a discharge opening from which the incompressible fluid is dischargeable and is parallel to the first straight portion, and a main portion that is located between the first straight portion and the second straight portion and includes a flow path through which the incompressible fluid is capable of flowing. The fixed mold or the movable mold includes a first holding portion through which the first straight portion is inserted, the first holding portion holding the first straight portion, and a second holding portion through which the second straight portion is inserted, the second holding portion holding the second straight portion. In a state where the first straight portion of the pipe is held by the first holding portion and the second straight portion of the pipe is held by the second holding portion, the main portion is not in contact with the fixed mold or the movable mold.

[0011] With the mold according to present example embodiment of the present invention, the main body of the pipe is not in contact with the fixed mold or the movable mold in a state where the first straight portion of the pipe is held by the first holding portion and the second straight portion of the pipe is held by the second holding portion. Therefore, in a state where the molding space is filled with the melted metal material, the metal material is cast with the entirety of the main portion of the pipe disposed therein. That is, in the produced cast product, the main portion of the pipe is not exposed outside.

[0012] According to example embodiments of the present invention, methods for producing cast products and cast product production devices by each of which an incompressible fluid filling the pipe incorporated into the cast product may be removed efficiently are provided.

[0013] The above and other elements, features, steps, characteristics and advantages of the present invention will become more apparent from the following detailed description of the example embodiments with reference to the attached drawings.BRIEF DESCRIPTION OF THE DRAWINGS

[0014] FIG. 1 is a schematic view of a cast product production device according to an example embodiment of the present invention.

[0015] FIG. 2 is a perspective view schematically showing a pipe according to an example embodiment of the present invention.

[0016] FIG. 3 is a perspective view schematically showing a cast product according to an example embodiment of the present invention.

[0017] FIG. 4 is a perspective view of a fixed mold according to an example embodiment of the present invention.

[0018] FIG. 5 is a side view showing a state where the pipe is held by the fixed mold according to an example embodiment of the present invention.

[0019] FIG. 6 is a flowchart showing a method for producing the cast product according to an example embodiment of the present invention.

[0020] FIG. 7 is a cross-sectional view showing a state where a mold is closed according to an example embodiment of the present invention.

[0021] FIG. 8 is a side view showing a state where a fluid transporter is coupled with the pipe held by the fixed mold according to an example embodiment of the present invention.

[0022] FIG. 9 is a cross-sectional view showing a state where the cast product is produced in the mold according to an example embodiment of the present invention.

[0023] FIG. 10 is a side view schematically showing a state where a movable mold is separated from the fixed mold to open the mold according to an example embodiment of the present invention.DETAILED DESCRIPTION OF THE EXAMPLE EMBODIMENTS

[0024] Hereinafter, example embodiments of cast product production devices according to the present invention will be described with reference to the drawings. Note that the example embodiments described herein are not intended to limit the present invention. Elements and portions having the same functions are denoted by the same reference signs, and description for the same elements and portions will not be repeated or will be simplified as appropriate.

[0025] FIG. 1 is a schematic view of a cast product production device 10 according to this example embodiment. The cast product production device 10 uses a diecast method, that is, a casting method performed at a high speed and a high pressure. Herein, the term “high pressure” refers to, for example, 20 MPa to 100 MPa. The cast product production device 10 produces a cast product 140 (see FIG. 3) including a pipe 100 (see FIG. 2) and a metal material 120, which is cast with the pipe 100 disposed therein. The cast product production device 10 includes a mold 20 and a fluid transporter 80.

[0026] The pipe 100 is formed of a metal material having a high thermal conductivity (e.g., an aluminum alloy). As shown in FIG. 2, the pipe 100 includes a first straight portion 102, a second straight portion 106 parallel to the first straight portion 102, and a main portion 110 located between the first straight portion 102 and the second straight portion 106. The first straight portion 102, the second straight portion 106 and the main portion 110 are formed integrally with each other. The first straight portion 102 includes an injection opening 103, into which an incompressible fluid is injectable, and a first flow path 104, which is in communication with the injection opening 103 and through which the incompressible fluid can flow. The second straight portion 106 includes a discharge opening 107, from which the incompressible fluid is dischargeable, and a second flow path 108, which is in communication with the discharge opening 107 and through which the incompressible fluid flows. The first straight portion 102 and the second straight portion 106 have the same length as each other from the main portion 110, but may have different lengths from each other from the main portion 110. The first straight portion 102 and the second straight portion 106 extend in the same direction as each other from the main portion 110. That is, the injection opening 103 and the discharge opening 107 are opened in the same direction as each other. The main portion 110 includes a third flow path 111, through which the incompressible fluid flows. The third flow path 111 is in communication with the first flow path 104 and the second flow path 108. That is, the third flow path 111 is in communication with the injection opening 103 and the discharge opening 107. The third flow path 111 is an example of flow path. The main portion 110 preferably has a spiral shape, for example. The main portion 110 is not limited to having a spiral shape.

[0027] As shown in FIG. 3, the cast product 140 includes the pipe 100 and the metal material 120, which is cast with the pipe 100 disposed therein. The pipe 100 and the metal material 120 are integral with each other. Among various portions of the pipe 100, a portion of the first straight portion 102, a portion of the second straight portion 106 and the entirety of the main portion 110 are covered with the metal material 120. A portion, of the first straight portion 102, that includes the injection opening 103, and a portion, of the second straight portion 106, that includes the discharge opening 107 are exposed outside from the metal material 120. The metal material 120 is formed of, for example, the same metal material as that of the pipe 100. The metal material 120 and the pipe 100 may be formed of different metal materials from each other. The cast product 140 is used as, for example, a case of a driving motor or the like.

[0028] As shown in FIG. 1, the mold 20 includes a fixed mold 30 and a movable mold 40 movable to approach, or to be separated from, the fixed mold 30. The fixed mold 30 includes a cavity 31 (see FIG. 7) formed therein, the cavity 31 being used to form a portion of the cast product 140. The fixed mold 30 has a recessed portion 30M recessed from an outer surface 30F (surface opposite to the movable mold 40) toward the cavity 31. The movable mold 40 includes a core 41 (see FIG. 7) formed therein, the core 41 being used to form another portion of the cast product 140. In a state where the movable mold 40 approaches the fixed mold 30 to close the mold 20, a molding space 50 (see FIG. 7) is formed by the movable mold 40 and the fixed mold 30. The pipe 100 is disposed in the molding space 50. The molding space 50 is defined by the cavity 31 and the core 41.

[0029] As shown in FIG. 4, the fixed mold 30 includes a first holding portion 32 holding the first straight portion 102 of the pipe 100 and a second holding portion 36 holding the second straight portion 106 of the pipe 100. The first holding portion 32 and the second holding portion 36 include through-holes formed in the fixed mold 30. The first holding portion 32 and the second holding portion 36 are in communication with the recessed portion 30M.

[0030] As shown in FIG. 5, the first straight portion 102 is inserted through the first holding portion 32. An inner diameter of the first holding portion 32 and an outer diameter of the first straight portion 102 are set such that in a state where the first straight portion 102 is inserted through the first holding portion 32, the first straight portion 102 is held by the first holding portion 32 and the first straight portion 102 is not loose with respect to the first holding portion 32. The inner diameter of the first holding portion 32 and the outer diameter of the first straight portion 102 are substantially the same as each other. A length of the first holding portion 32 in a longitudinal direction thereof is set such that in a state where the first straight portion 102 is held by the first holding portion 32, the first straight portion 102 is exposed outside from the mold 20 (in this example embodiment, the fixed mold 30). The length of the first holding portion 32 in the longitudinal direction thereof is shorter than a length of the first straight portion 102 in a longitudinal direction thereof. In a state where the first straight portion 102 is inserted through the first holding portion 32 (that is, in a state where the pipe 100 is disposed in the molding space 50), a portion of the first straight portion 102 is exposed outside from the mold 20 (in this example embodiment, the fixed mold 30). That is, the injection opening 103 is exposed outside from the fixed mold 30. The injection opening 103 is located in the recessed portion 30M of the fixed mold 30. The injection opening 103 may be located outer to the recessed portion 30M.

[0031] As shown in FIG. 5, the second straight portion 106 is inserted through the second holding portion 36. An inner diameter of the second holding portion 36 and an outer diameter of the second straight portion 106 are set such that in a state where the second straight portion 106 is inserted through the second holding portion 36, the second straight portion 106 is held by the second holding portion 36 and the second straight portion 106 is not loose with respect to the second holding portion 36. The inner diameter of the second holding portion 36 and the outer diameter of the second straight portion 106 are substantially the same as each other. A length of the second holding portion 36 in a longitudinal direction thereof is set such that in a state where the second straight portion 106 is held by the second holding portion 36, the second straight portion 106 is exposed outside from the mold 20 (in this example embodiment, the fixed mold 30). The length of the second holding portion 36 in the longitudinal direction thereof is shorter than a length of the second straight portion 106 in a longitudinal direction thereof. In a state where the second straight portion 106 is inserted through the second holding portion 36 (that is, in a state where the pipe 100 is disposed in the molding space 50), a portion of the second straight portion 106 is exposed outside from the mold 20 (in this example embodiment, the fixed mold 30). That is, the discharge opening 107 is exposed outside from the fixed mold 30. The discharge opening 107 is located in the recessed portion 30M of the fixed mold 30. The discharge opening 107 may be located outer to the recessed portion 30M. Neither the first straight portion 102 nor the second straight portion 106 needs to be exposed outside from the mold 20 (in this example embodiment, the fixed mold 30). In the case where the first straight portion 102 or the second straight portion 106 is not exposed outside from the mold 20, for example, the incompressible fluid may be injected into the injection opening 103 of the pipe 100 via the first holding portion 32 or the incompressible fluid may be discharged from the discharge opening 107 of the pipe 100 via the second holding portion 36.

[0032] As shown in FIG. 5, in a state where the first straight portion 102 of the pipe 100 is held by the first holding portion 32 and the second straight portion 106 of the pipe 100 is held by the second holding portion 36, the pipe 100 is held by the fixed mold 30. That is, the pipe 100 is held by the fixed mold 30 only via the first holding portion 32 and the second holding portion 36. In a state where the first straight portion 102 of the pipe 100 is held by the first holding portion 32 and the second straight portion 106 of the pipe 100 is held by the second holding portion 36, the main portion 110 of the pipe 100 is not in contact with the fixed mold 30 or the movable mold 40 (see FIG. 7). In other words, there is a gap provided between the entirety of the main portion 110 of the pipe 100 and the fixed mold 30 and between the entirety of the main portion 110 of the pipe 100 and the movable mold 40. That is, the pipe 100 is held by the fixed mold 30 in a state where the main portion 110 is floating in the air. In this example embodiment, the first holding portion 32 and the second holding portion 36 are provided in the fixed mold 30. Alternatively, the first holding portion 32 and the second holding portion 36 may be provided in the movable mold 40.

[0033] As shown in FIG. 1, the fixed mold 30 includes a first pressing portion 38 to press the first straight portion 102 of the pipe 100 sideways and a second pressing portion 39 to press the second straight portion 106 of the pipe 100 sideways. The first pressing portion 38 and the second pressing portion 39 are, for example, rod-shaped structures. The first pressing portion 38 is accommodated in a first accommodation hole 32H formed in the fixed mold 30 and is movable in the first accommodation hole 32H. The first accommodation hole 32H extends in a direction crossing (e.g., crossing perpendicularly to) the first holding portion 32. The second pressing portion 39 is accommodated in a second accommodation hole 36H formed in the fixed mold 30 and is movable in the second accommodation hole 36H. The second accommodation hole 36H extends in a direction crossing (e. g., crossing perpendicularly to) the second holding portion 36. The first pressing portion 38 and the second pressing portion 39 respectively press the first straight portion 102 and the second straight portion 106 sideways after the pipe 100 is filled with the incompressible fluid. The first pressing portion 38 and the second pressing portion 39 may respectively press the first straight portion 102 and the second straight portion 106 sideways before the pipe 100 is filled with the incompressible fluid. The movement of first pressing portion 38 and the second pressing portion 39 is controlled by, for example, a solenoid or the like (not shown). The first pressing portion 38 presses the first straight portion 102 sideways to secure the first straight portion 102 at a predetermined position. The second pressing portion 39 presses the second straight portion 106 sideways to secure the second straight portion 106 at a predetermined position. In this example embodiment, the first pressing portion 38 and the second pressing portion 39 are provided in the fixed mold 30. In the case where the first holding portion 32 and the second holding portion 36 are provided in the movable mold 40, the first pressing portion 38 and the second pressing portion 39 may be provided in the movable mold 40. It is sufficient that at least one of the first pressing portion 38 and the second pressing portion 39 is provided.

[0034] As shown in FIG. 7, the mold 20 includes a slide portion 35. The slide portion 35 is a portion of the fixed mold 30. The slide portion 35 is inserted into a spiral portion of the main portion 110 of the pipe 100 disposed in the molding space 50. The slide portion 35 has a cylindrical shape. The slide portion 35 is not in contact with the main portion 110. The slide portion 35 is movable with respect to the pipe 100.

[0035] As shown in FIG. 1, the fluid transporter 80 is separate from the mold 20. The fluid transporter 80 injects the incompressible fluid into the injection opening 103 of the pipe 100. The fluid transporter 80 discharges the incompressible fluid from the discharge opening 107 of the pipe 100 to recover the incompressible fluid. The incompressible fluid may be any type of fluid that, by filling the pipe 100, prevents the pipe 100 from being deformed even if a load is applied to the pipe 100. The incompressible fluid is, for example, oil (e.g., hydraulic oil). The fluid transporter 80 is attached to the injection opening 103 and the discharge opening 107 of the pipe 100 disposed in the molding space 50 (see FIG. 7) of the mold 20. The fluid transporter 80 includes a transportation portion 82 feeding the incompressible fluid and a recovery portion 84 recovering the incompressible fluid. The transportation portion 82 and the recovery portion 84 are each, for example, a pressure-resistant and heat-resistant hose. The transportation portion 82 is attached to the first straight portion 102 of the pipe 100. The transportation portion 82 is in communication with the injection opening 103 of the first straight portion 102. The recovery portion 84 is attached to the second straight portion 106 of the pipe 100. The recovery portion 84 is in communication with the discharge opening 107 of the second straight portion 106. There is no specific limitation on the method for attaching the transportation portion 82 to the first straight portion 102 or the method for attaching the recovery portion 84 to the second straight portion 106. The transportation portion 82 and the recovery portion 84 may be attachable / detachable by, for example, a coupler (one-touch joint) or the like.

[0036] Now, a non-limiting example of a method for producing the cast product 140 according to this example embodiment will be described. FIG. 6 is a flowchart showing a method for producing the cast product 140 (hereinafter, the method will be referred to simply as the “production method”). As shown in FIG. 6, the production method includes a preparation step (step S10), a disposing step (step S20), a clamping step (step S30), a first filling step (step S40), a second filling step (step S50), a discharge step (step S60), and an extraction step (step S70). In this example embodiment, as shown in FIG. 1, the cast product 140 (see FIG. 3) is produced by use of the cast product production device 10 including the mold 20 and the fluid transporter 80. In FIG. 7 through FIG. 10, a direction in which the movable mold 40 moves with respect to the fixed mold 30 is represented as “P”. A direction in which the movable mold 40 approaches the fixed mold 30 is represented as “P1”, and a direction in which the movable mold 40 separates from the fixed mold 30 is represented as “P2”.

[0037] First, in the preparation step (step S10), as shown in FIG. 1, the mold 20 including the fixed mold 30 and the movable mold 40 movable to approach, or to be separated from, the fixed mold 30 is prepared.

[0038] Next, in the disposing step (step S20), the pipe 100 is disposed in the mold 20. In more detail, as shown in FIG. 5, the first straight portion 102 of the pipe 100 is inserted through, and thus held by, the first holding portion 32 of the fixed mold 30, and the second straight portion 106 of the pipe 100 is inserted through, and thus held by, the second holding portion 36 of the fixed mold 30. As a result, the injection opening 103 of the first straight portion 102 and the discharge opening 107 of the second straight portion 106 are exposed outside from the mold 20 (in this example embodiment, the fixed mold 30) (see FIG. 1).

[0039] Next, in the clamping step (step S30), as shown in FIG. 7, the movable mold 40 approaches the fixed mold 30 to close the mold 20. That is, the movable mold 40 is moved in a direction of arrow P1 in FIG. 7 to close the fixed mold 30. As a result, the molding space 50, in which the cast product 140 is to be molded, is defined by the cavity 31 of the fixed mold 30 and the core 41 of the movable mold 40. Before the movable mold 40 approaches the fixed mold 30, the slide portion 35 of the mold 20 (see also FIG. 1) is moved to be disposed inner to the main portion 110 of the pipe 100. In a state where the mold 20 is closed, the main portion 110 of the pipe 100 is not in contact with the fixed mold 30 or the movable mold 40. Only the first straight portion 102 and the second straight portion 106 of the pipe 100 are in contact with the mold 20 (in this example embodiment, the fixed mold 30).

[0040] Next, in the first filling step (step S40), the incompressible fluid (e.g., oil) is injected into the injection opening 103 of the first straight portion 102 to fill the third flow path 111 of the main portion 110. In more detail, as shown in FIG. 8, the transportation portion 82 of the fluid transporter 80 is attached to the first straight portion 102 of the pipe 100 by a one-touch joint or the like, and the recovery portion 84 of the fluid transporter 80 is attached to the second straight portion 106 of the pipe 100 by a one-touch joint or the like. The first flow path 104, the second flow path 108 and the third flow path 111 of the pipe 100 are filled with the incompressible fluid via the injection opening 103 from the fluid transporter 80. After the filling of the pipe 100 with the incompressible fluid is finished, the fluid transporter 80 may be detached from the pipe 100 or may be kept attached thereto. After the filling of the pipe 100 with the incompressible fluid is finished, the first pressing portion 38 presses the first straight portion 102 of the pipe 100 sideways and the second pressing portion 39 presses the second straight portion 106 of the pipe 100 sideways, and as a result, the first straight portion 102 and the second straight portion 106 are secured at the predetermined positions. In this example embodiment, the first filling step (step S40) is performed after the clamping step (step S30). Alternatively, the clamping step (step S30) may be performed after the first filling step (step S40).

[0041] Next, in the second filling step S50, the molding space 50 formed by the movable mold 40 and the fixed mold 30 is filled with a melted metal material. The metal material is, for example, an aluminum alloy. The melted metal material (molten metal) is injected into an injection opening (not shown) provided in the fixed mold 30 to fill the molding space 50. The melted metal material (molten metal) is cooled and thus coagulated in the mold 20. In this specification, the term “cooling” refers to cooling performed to coagulate the molten metal.

[0042] Next, in the discharge step (step S60), the incompressible fluid filling the third flow path 111 of the main portion 110 is discharged from the discharge opening 107 of the second straight portion 106 of the cast product 140. In more detail, as shown in FIG. 9, the fluid transporter 80 is driven to discharge the incompressible fluid from the discharge opening 107 of the second straight portion 106 of the pipe 100 toward the fluid transporter 80. The incompressible fluid discharged from the discharge opening 107 is recovered into the fluid transporter 80. After the incompressible fluid is discharged from the pipe 100, the fluid transporter 80 is detached from the pipe 100. The discharge step (step S60) is performed in a state where the cast product 140 is disposed in the mold 20. The discharge step (step S60) may be performed after the molten metal in the mold 20 is completely coagulated or in the middle of the molten metal being coagulated. That is, the discharge of the incompressible fluid may be started after a curing time (time required for the cooling performed to coagulate the molten metal) elapses or before the curing time elapses.

[0043] Next, in the extraction step (step S70), as shown in FIG. 10, the movable mold 40 is separated from the fixed mold 30 to open the mold 20. That is, the movable mold 40 is moved in a direction of arrow P2 in FIG. 10 to be separated from the fixed mold 30. At this point, the cast product 140 produced by molding is fixed to the movable mold 40. A core pin (not shown) is pressed onto the cast product 140 fixed to the movable mold 40 to extract the cast product 140, having the incompressible fluid already discharged from the third flow path 111 of the main portion 110 of the pipe 100, from the movable mold 40. In this manner, the cast product 140 including the pipe 100 and the metal material 120, which is cast with the pipe 100 disposed therein, is produced by molding.

[0044] As described above, according to the production method in this example embodiment, the incompressible fluid is injected into the injection opening 103 in a state where the pipe 100 is disposed in the mold 20, and after the molding space 50 is filled with the melted metal material, the incompressible fluid is discharged from the discharge opening 107 in a state where the pipe 100 is disposed in the mold 20. Thus, the incompressible fluid filling the third flow path 111 of the main portion 110 of the pipe 100 is discharged from the discharge opening 107 in a state where the cast product 140 is present in the mold 20. Therefore, the cast product 140 does not need to be set in a device for removing the incompressible fluid, and thus the time for producing the cast product 140 may be shortened. In the case where the cast product 140 is extracted from the mold 20 in a state where the third flow path 111 of the main portion 110 of the pipe 100 is filled with the incompressible fluid, there is an undesirable possibility that the incompressible fluid splatters outside through the injection opening 103 or the discharge opening 107 of the pipe 100. However, according to the above-described production method, the incompressible fluid has already been discharged when the cast product 140 is extracted from the mold 20. Therefore, there is no possibility that the incompressible fluid splatters outside.

[0045] According to the cast product production device 10 in this example embodiment, the fluid transporter 80 attached to the injection opening 103 and the discharge opening 107 of the pipe 100 disposed in the molding space 50 injects the incompressible fluid into the injection opening 103 and discharges the incompressible fluid from the discharge opening 107. Thus, the incompressible fluid may be discharged from the discharge opening 107 of the pipe 100 in a state where the pipe 100 is disposed in the mold 20. Therefore, the cast product 140 does not need to be set in a device for removing the incompressible fluid, and thus the time for producing the cast product 140 may be shortened. In addition, the relative positions of the fluid transporter 80 and the mold 20 is not changed whether the incompressible fluid may be injected into the injection opening 103 or discharged from the discharge opening 107. Therefore, the injection and the discharge of the incompressible fluid may be performed with high precision.

[0046] According to the mold 20 in this example embodiment, the main body 110 of the pipe 100 is not in contact with the fixed mold 30 or the movable mold 40 in a state where the first straight portion 102 of the pipe 100 is held by the first holding portion 32 and the second straight portion 106 of the pipe 100 is held by the second holding portion 36. Therefore, in a state where the molding space 50 is filled with the melted metal material, the metal material is cast with the entirety of the main portion 110 of the pipe 100 disposed therein. That is, in the produced cast product 140, the main portion 110 of the pipe 100 is not exposed outside.

[0047] According to the mold 20 in this example embodiment, the lengths of the first holding portion 32 and the second holding portion 36 are set such that in a state where the first straight portion 102 of the pipe 100 is held by the first holding portion 32 and the second straight portion 106 of the pipe 100 is held by the second holding portion 36, the first straight portion 102 and the second straight portion 106 are exposed outside. According to this example embodiment, the fluid transporter 80 may be easily attached to the first straight portion 102 and the second straight portion 106 exposed outside from the mold 20.

[0048] According to the mold 20 in this example embodiment, the fixed mold 30 including the first holding portion 32 and the second holding portion 36 includes the first pressing portion 38 pressing the first straight portion 102 sideways and the second pressing portion 39 pressing the second straight portion 106 sideways. According to this example embodiment, the first straight portion 102 and / or the second straight portion 106 of the pipe 100 may be secured to the predetermined position.

[0049] While example embodiments of the present invention have been described above, it is to be understood that variations and modifications will be apparent to those skilled in the art without departing from the scope and spirit of the present invention. The scope of the present invention, therefore, is to be determined solely by the following claims.

Examples

Embodiment Construction

[0024]Hereinafter, example embodiments of cast product production devices according to the present invention will be described with reference to the drawings. Note that the example embodiments described herein are not intended to limit the present invention. Elements and portions having the same functions are denoted by the same reference signs, and description for the same elements and portions will not be repeated or will be simplified as appropriate.

[0025]FIG. 1 is a schematic view of a cast product production device 10 according to this example embodiment. The cast product production device 10 uses a diecast method, that is, a casting method performed at a high speed and a high pressure. Herein, the term “high pressure” refers to, for example, 20 MPa to 100 MPa. The cast product production device 10 produces a cast product 140 (see FIG. 3) including a pipe 100 (see FIG. 2) and a metal material 120, which is cast with the pipe 100 disposed therein. The cast product production dev...

BACKGROUND OF THE INVENTION1. Field of the Invention

[0001] The present invention relates to methods for producing cast products, cast product production devices, and molds.2. Description of the Related Art

[0002] Conventionally, a method called “insert casting” is used for producing a cast product. For example, a cast product produced by the insert casting has a pipe, pre-produced separately from the cast product itself, incorporated thereto. In more detail, according to the insert casting, a pipe is preset in a mold for producing a cast product, and then a molten metal, produced by a metal material such as an aluminum alloy or the like being melted, is injected into the mold. As a result, a cast product having the pipe incorporated thereto is produced. An example of cast product having such a pipe incorporated thereto is a case of a driving motor or the like.

[0003] For example, Japanese Patent Application Publication No. 2020-124743 discloses a method for producing a cast product by which a smart core including a tubular pipe filled with a filling material is inserted into a mold having a cavity formed therein, a molten metal is injected into the cavity, and then the filling material is removed from the smart core.SUMMARY OF THE INVENTION

[0004] According to Japanese Patent Application Publication No. 2020-124743, the filling material in the tubular pipe is removed after the cast product having the smart core incorporated thereto is extracted from the mold. That is, after the cast product is taken out from the mold, the cast product needs to be set in a device for removing the filling material. This may undesirably extend the time to produce the cast product.

[0005] Example embodiments of the present invention provide methods for producing cast products and cast product production devices by each of which an incompressible fluid filling the pipe incorporated into the cast product is removed efficiently.

[0006] A method for producing a cast product according to an example embodiment of the present invention is a method for producing a cast product including a pipe including an injection opening into which an incompressible fluid is injectable, a discharge opening from which the incompressible fluid is dischargeable, and a flow path located between the injection opening and the discharge opening to allow the incompressible fluid to flow therethrough, and a metal material that is cast with the pipe disposed therein. The method includes preparing a mold including a fixed mold and a movable mold movable to approach, or to be separated from, the fixed mold, disposing the pipe in the mold such that the injection opening and the discharge opening are exposed outside from the mold, causing the movable mold to approach the fixed mold to close the mold, injecting the incompressible fluid into the injection opening to fill the flow path with the incompressible fluid, filling a molding space formed by the movable mold and the fixed mold with a melted metal material, discharging the incompressible fluid in the flow path from the discharge opening, and separating the movable mold from the fixed mold to open the mold and extracting the cast product having the incompressible fluid discharged from the flow path.

[0007] With the production method according to the present example embodiment of the present invention, the incompressible fluid is injected into the injection opening in a state where the pipe is disposed in the mold, and after the molding space is filled with the melted metal material, the incompressible fluid is discharged from the discharge opening in a state where the pipe is disposed in the mold. Thus, the incompressible fluid filling the flow path of the pipe is discharged from the discharge opening in a state where the cast product is present in the mold. Therefore, the cast product does not need to be set in a device for removing the incompressible fluid, and thus the time for producing the cast product may be shortened. In the case where the cast product is extracted from the mold in a state where the flow path of the pipe is filled with the incompressible fluid, there is an undesirable possibility that the incompressible fluid splatters outside through the injection opening or the discharge opening of the pipe. However, according to the above-described production method, the incompressible fluid has already been discharged when the cast product is extracted from the mold. Therefore, there is no possibility that the incompressible fluid splatters outside.

[0008] A cast product production device according to an example embodiment of the present invention includes a mold including a fixed mold and a movable mold movable to approach, or to be separated from, the fixed mold, the mold being configured such that in a state where a pipe including a first straight portion that includes an injection opening into which an incompressible fluid is injectable, a second straight portion that includes a discharge opening from the which incompressible fluid is dischargeable, and a main portion that is located between the first straight portion and the second straight portion and includes a flow path through which the incompressible fluid flows is in a molding space formed by the movable mold and the fixed mold, the injection opening and the discharge opening are exposed outside, and a fluid transporter attachable to the injection opening and the discharge opening of the pipe in the molding space, the fluid transporter injecting the incompressible fluid into the injection opening and discharging the incompressible fluid from the discharge opening.

[0009] With the cast product production device according to the present example embodiment of the present invention, the fluid transporter attached to the injection opening and the discharge opening of the pipe in the molding space injects the incompressible fluid into the injection opening and discharges the incompressible fluid from the discharge opening. Thus, the incompressible fluid may be discharged from the discharge opening of the pipe in a state where the pipe is disposed in the mold. Therefore, the cast product does not need to be set in a device for removing the incompressible fluid, and thus the time for producing the cast product may be shortened. In addition, the relative positions of the fluid transporter and the mold are not changed whether the incompressible fluid may be injected into the injection opening or discharged from the discharge opening. Therefore, the injection and the discharge of the incompressible fluid may be performed with high precision.

[0010] A mold according to an example embodiment of the present invention includes a fixed mold, and a movable mold movable to approach, or to be separated from, the fixed mold. The mold is configured such that a pipe is in a molding space formed by the movable mold and the fixed mold, the pipe including a first straight portion that includes an injection opening into which an incompressible fluid is injectable, a second straight portion that includes a discharge opening from which the incompressible fluid is dischargeable and is parallel to the first straight portion, and a main portion that is located between the first straight portion and the second straight portion and includes a flow path through which the incompressible fluid is capable of flowing. The fixed mold or the movable mold includes a first holding portion through which the first straight portion is inserted, the first holding portion holding the first straight portion, and a second holding portion through which the second straight portion is inserted, the second holding portion holding the second straight portion. In a state where the first straight portion of the pipe is held by the first holding portion and the second straight portion of the pipe is held by the second holding portion, the main portion is not in contact with the fixed mold or the movable mold.

[0011] With the mold according to present example embodiment of the present invention, the main body of the pipe is not in contact with the fixed mold or the movable mold in a state where the first straight portion of the pipe is held by the first holding portion and the second straight portion of the pipe is held by the second holding portion. Therefore, in a state where the molding space is filled with the melted metal material, the metal material is cast with the entirety of the main portion of the pipe disposed therein. That is, in the produced cast product, the main portion of the pipe is not exposed outside.

[0012] According to example embodiments of the present invention, methods for producing cast products and cast product production devices by each of which an incompressible fluid filling the pipe incorporated into the cast product may be removed efficiently are provided.

[0013] The above and other elements, features, steps, characteristics and advantages of the present invention will become more apparent from the following detailed description of the example embodiments with reference to the attached drawings.BRIEF DESCRIPTION OF THE DRAWINGS

[0014] FIG. 1 is a schematic view of a cast product production device according to an example embodiment of the present invention.

[0015] FIG. 2 is a perspective view schematically showing a pipe according to an example embodiment of the present invention.

[0016] FIG. 3 is a perspective view schematically showing a cast product according to an example embodiment of the present invention.

[0017] FIG. 4 is a perspective view of a fixed mold according to an example embodiment of the present invention.

[0018] FIG. 5 is a side view showing a state where the pipe is held by the fixed mold according to an example embodiment of the present invention.

[0019] FIG. 6 is a flowchart showing a method for producing the cast product according to an example embodiment of the present invention.

[0020] FIG. 7 is a cross-sectional view showing a state where a mold is closed according to an example embodiment of the present invention.

[0021] FIG. 8 is a side view showing a state where a fluid transporter is coupled with the pipe held by the fixed mold according to an example embodiment of the present invention.

[0022] FIG. 9 is a cross-sectional view showing a state where the cast product is produced in the mold according to an example embodiment of the present invention.

[0023] FIG. 10 is a side view schematically showing a state where a movable mold is separated from the fixed mold to open the mold according to an example embodiment of the present invention.DETAILED DESCRIPTION OF THE EXAMPLE EMBODIMENTS

[0024] Hereinafter, example embodiments of cast product production devices according to the present invention will be described with reference to the drawings. Note that the example embodiments described herein are not intended to limit the present invention. Elements and portions having the same functions are denoted by the same reference signs, and description for the same elements and portions will not be repeated or will be simplified as appropriate.

[0025] FIG. 1 is a schematic view of a cast product production device 10 according to this example embodiment. The cast product production device 10 uses a diecast method, that is, a casting method performed at a high speed and a high pressure. Herein, the term “high pressure” refers to, for example, 20 MPa to 100 MPa. The cast product production device 10 produces a cast product 140 (see FIG. 3) including a pipe 100 (see FIG. 2) and a metal material 120, which is cast with the pipe 100 disposed therein. The cast product production device 10 includes a mold 20 and a fluid transporter 80.

[0026] The pipe 100 is formed of a metal material having a high thermal conductivity (e.g., an aluminum alloy). As shown in FIG. 2, the pipe 100 includes a first straight portion 102, a second straight portion 106 parallel to the first straight portion 102, and a main portion 110 located between the first straight portion 102 and the second straight portion 106. The first straight portion 102, the second straight portion 106 and the main portion 110 are formed integrally with each other. The first straight portion 102 includes an injection opening 103, into which an incompressible fluid is injectable, and a first flow path 104, which is in communication with the injection opening 103 and through which the incompressible fluid can flow. The second straight portion 106 includes a discharge opening 107, from which the incompressible fluid is dischargeable, and a second flow path 108, which is in communication with the discharge opening 107 and through which the incompressible fluid flows. The first straight portion 102 and the second straight portion 106 have the same length as each other from the main portion 110, but may have different lengths from each other from the main portion 110. The first straight portion 102 and the second straight portion 106 extend in the same direction as each other from the main portion 110. That is, the injection opening 103 and the discharge opening 107 are opened in the same direction as each other. The main portion 110 includes a third flow path 111, through which the incompressible fluid flows. The third flow path 111 is in communication with the first flow path 104 and the second flow path 108. That is, the third flow path 111 is in communication with the injection opening 103 and the discharge opening 107. The third flow path 111 is an example of flow path. The main portion 110 preferably has a spiral shape, for example. The main portion 110 is not limited to having a spiral shape.

[0027] As shown in FIG. 3, the cast product 140 includes the pipe 100 and the metal material 120, which is cast with the pipe 100 disposed therein. The pipe 100 and the metal material 120 are integral with each other. Among various portions of the pipe 100, a portion of the first straight portion 102, a portion of the second straight portion 106 and the entirety of the main portion 110 are covered with the metal material 120. A portion, of the first straight portion 102, that includes the injection opening 103, and a portion, of the second straight portion 106, that includes the discharge opening 107 are exposed outside from the metal material 120. The metal material 120 is formed of, for example, the same metal material as that of the pipe 100. The metal material 120 and the pipe 100 may be formed of different metal materials from each other. The cast product 140 is used as, for example, a case of a driving motor or the like.

[0028] As shown in FIG. 1, the mold 20 includes a fixed mold 30 and a movable mold 40 movable to approach, or to be separated from, the fixed mold 30. The fixed mold 30 includes a cavity 31 (see FIG. 7) formed therein, the cavity 31 being used to form a portion of the cast product 140. The fixed mold 30 has a recessed portion 30M recessed from an outer surface 30F (surface opposite to the movable mold 40) toward the cavity 31. The movable mold 40 includes a core 41 (see FIG. 7) formed therein, the core 41 being used to form another portion of the cast product 140. In a state where the movable mold 40 approaches the fixed mold 30 to close the mold 20, a molding space 50 (see FIG. 7) is formed by the movable mold 40 and the fixed mold 30. The pipe 100 is disposed in the molding space 50. The molding space 50 is defined by the cavity 31 and the core 41.

[0029] As shown in FIG. 4, the fixed mold 30 includes a first holding portion 32 holding the first straight portion 102 of the pipe 100 and a second holding portion 36 holding the second straight portion 106 of the pipe 100. The first holding portion 32 and the second holding portion 36 include through-holes formed in the fixed mold 30. The first holding portion 32 and the second holding portion 36 are in communication with the recessed portion 30M.

[0030] As shown in FIG. 5, the first straight portion 102 is inserted through the first holding portion 32. An inner diameter of the first holding portion 32 and an outer diameter of the first straight portion 102 are set such that in a state where the first straight portion 102 is inserted through the first holding portion 32, the first straight portion 102 is held by the first holding portion 32 and the first straight portion 102 is not loose with respect to the first holding portion 32. The inner diameter of the first holding portion 32 and the outer diameter of the first straight portion 102 are substantially the same as each other. A length of the first holding portion 32 in a longitudinal direction thereof is set such that in a state where the first straight portion 102 is held by the first holding portion 32, the first straight portion 102 is exposed outside from the mold 20 (in this example embodiment, the fixed mold 30). The length of the first holding portion 32 in the longitudinal direction thereof is shorter than a length of the first straight portion 102 in a longitudinal direction thereof. In a state where the first straight portion 102 is inserted through the first holding portion 32 (that is, in a state where the pipe 100 is disposed in the molding space 50), a portion of the first straight portion 102 is exposed outside from the mold 20 (in this example embodiment, the fixed mold 30). That is, the injection opening 103 is exposed outside from the fixed mold 30. The injection opening 103 is located in the recessed portion 30M of the fixed mold 30. The injection opening 103 may be located outer to the recessed portion 30M.

[0031] As shown in FIG. 5, the second straight portion 106 is inserted through the second holding portion 36. An inner diameter of the second holding portion 36 and an outer diameter of the second straight portion 106 are set such that in a state where the second straight portion 106 is inserted through the second holding portion 36, the second straight portion 106 is held by the second holding portion 36 and the second straight portion 106 is not loose with respect to the second holding portion 36. The inner diameter of the second holding portion 36 and the outer diameter of the second straight portion 106 are substantially the same as each other. A length of the second holding portion 36 in a longitudinal direction thereof is set such that in a state where the second straight portion 106 is held by the second holding portion 36, the second straight portion 106 is exposed outside from the mold 20 (in this example embodiment, the fixed mold 30). The length of the second holding portion 36 in the longitudinal direction thereof is shorter than a length of the second straight portion 106 in a longitudinal direction thereof. In a state where the second straight portion 106 is inserted through the second holding portion 36 (that is, in a state where the pipe 100 is disposed in the molding space 50), a portion of the second straight portion 106 is exposed outside from the mold 20 (in this example embodiment, the fixed mold 30). That is, the discharge opening 107 is exposed outside from the fixed mold 30. The discharge opening 107 is located in the recessed portion 30M of the fixed mold 30. The discharge opening 107 may be located outer to the recessed portion 30M. Neither the first straight portion 102 nor the second straight portion 106 needs to be exposed outside from the mold 20 (in this example embodiment, the fixed mold 30). In the case where the first straight portion 102 or the second straight portion 106 is not exposed outside from the mold 20, for example, the incompressible fluid may be injected into the injection opening 103 of the pipe 100 via the first holding portion 32 or the incompressible fluid may be discharged from the discharge opening 107 of the pipe 100 via the second holding portion 36.

[0032] As shown in FIG. 5, in a state where the first straight portion 102 of the pipe 100 is held by the first holding portion 32 and the second straight portion 106 of the pipe 100 is held by the second holding portion 36, the pipe 100 is held by the fixed mold 30. That is, the pipe 100 is held by the fixed mold 30 only via the first holding portion 32 and the second holding portion 36. In a state where the first straight portion 102 of the pipe 100 is held by the first holding portion 32 and the second straight portion 106 of the pipe 100 is held by the second holding portion 36, the main portion 110 of the pipe 100 is not in contact with the fixed mold 30 or the movable mold 40 (see FIG. 7). In other words, there is a gap provided between the entirety of the main portion 110 of the pipe 100 and the fixed mold 30 and between the entirety of the main portion 110 of the pipe 100 and the movable mold 40. That is, the pipe 100 is held by the fixed mold 30 in a state where the main portion 110 is floating in the air. In this example embodiment, the first holding portion 32 and the second holding portion 36 are provided in the fixed mold 30. Alternatively, the first holding portion 32 and the second holding portion 36 may be provided in the movable mold 40.

[0033] As shown in FIG. 1, the fixed mold 30 includes a first pressing portion 38 to press the first straight portion 102 of the pipe 100 sideways and a second pressing portion 39 to press the second straight portion 106 of the pipe 100 sideways. The first pressing portion 38 and the second pressing portion 39 are, for example, rod-shaped structures. The first pressing portion 38 is accommodated in a first accommodation hole 32H formed in the fixed mold 30 and is movable in the first accommodation hole 32H. The first accommodation hole 32H extends in a direction crossing (e.g., crossing perpendicularly to) the first holding portion 32. The second pressing portion 39 is accommodated in a second accommodation hole 36H formed in the fixed mold 30 and is movable in the second accommodation hole 36H. The second accommodation hole 36H extends in a direction crossing (e. g., crossing perpendicularly to) the second holding portion 36. The first pressing portion 38 and the second pressing portion 39 respectively press the first straight portion 102 and the second straight portion 106 sideways after the pipe 100 is filled with the incompressible fluid. The first pressing portion 38 and the second pressing portion 39 may respectively press the first straight portion 102 and the second straight portion 106 sideways before the pipe 100 is filled with the incompressible fluid. The movement of first pressing portion 38 and the second pressing portion 39 is controlled by, for example, a solenoid or the like (not shown). The first pressing portion 38 presses the first straight portion 102 sideways to secure the first straight portion 102 at a predetermined position. The second pressing portion 39 presses the second straight portion 106 sideways to secure the second straight portion 106 at a predetermined position. In this example embodiment, the first pressing portion 38 and the second pressing portion 39 are provided in the fixed mold 30. In the case where the first holding portion 32 and the second holding portion 36 are provided in the movable mold 40, the first pressing portion 38 and the second pressing portion 39 may be provided in the movable mold 40. It is sufficient that at least one of the first pressing portion 38 and the second pressing portion 39 is provided.

[0034] As shown in FIG. 7, the mold 20 includes a slide portion 35. The slide portion 35 is a portion of the fixed mold 30. The slide portion 35 is inserted into a spiral portion of the main portion 110 of the pipe 100 disposed in the molding space 50. The slide portion 35 has a cylindrical shape. The slide portion 35 is not in contact with the main portion 110. The slide portion 35 is movable with respect to the pipe 100.

[0035] As shown in FIG. 1, the fluid transporter 80 is separate from the mold 20. The fluid transporter 80 injects the incompressible fluid into the injection opening 103 of the pipe 100. The fluid transporter 80 discharges the incompressible fluid from the discharge opening 107 of the pipe 100 to recover the incompressible fluid. The incompressible fluid may be any type of fluid that, by filling the pipe 100, prevents the pipe 100 from being deformed even if a load is applied to the pipe 100. The incompressible fluid is, for example, oil (e.g., hydraulic oil). The fluid transporter 80 is attached to the injection opening 103 and the discharge opening 107 of the pipe 100 disposed in the molding space 50 (see FIG. 7) of the mold 20. The fluid transporter 80 includes a transportation portion 82 feeding the incompressible fluid and a recovery portion 84 recovering the incompressible fluid. The transportation portion 82 and the recovery portion 84 are each, for example, a pressure-resistant and heat-resistant hose. The transportation portion 82 is attached to the first straight portion 102 of the pipe 100. The transportation portion 82 is in communication with the injection opening 103 of the first straight portion 102. The recovery portion 84 is attached to the second straight portion 106 of the pipe 100. The recovery portion 84 is in communication with the discharge opening 107 of the second straight portion 106. There is no specific limitation on the method for attaching the transportation portion 82 to the first straight portion 102 or the method for attaching the recovery portion 84 to the second straight portion 106. The transportation portion 82 and the recovery portion 84 may be attachable / detachable by, for example, a coupler (one-touch joint) or the like.

[0036] Now, a non-limiting example of a method for producing the cast product 140 according to this example embodiment will be described. FIG. 6 is a flowchart showing a method for producing the cast product 140 (hereinafter, the method will be referred to simply as the “production method”). As shown in FIG. 6, the production method includes a preparation step (step S10), a disposing step (step S20), a clamping step (step S30), a first filling step (step S40), a second filling step (step S50), a discharge step (step S60), and an extraction step (step S70). In this example embodiment, as shown in FIG. 1, the cast product 140 (see FIG. 3) is produced by use of the cast product production device 10 including the mold 20 and the fluid transporter 80. In FIG. 7 through FIG. 10, a direction in which the movable mold 40 moves with respect to the fixed mold 30 is represented as “P”. A direction in which the movable mold 40 approaches the fixed mold 30 is represented as “P1”, and a direction in which the movable mold 40 separates from the fixed mold 30 is represented as “P2”.

[0037] First, in the preparation step (step S10), as shown in FIG. 1, the mold 20 including the fixed mold 30 and the movable mold 40 movable to approach, or to be separated from, the fixed mold 30 is prepared.

[0038] Next, in the disposing step (step S20), the pipe 100 is disposed in the mold 20. In more detail, as shown in FIG. 5, the first straight portion 102 of the pipe 100 is inserted through, and thus held by, the first holding portion 32 of the fixed mold 30, and the second straight portion 106 of the pipe 100 is inserted through, and thus held by, the second holding portion 36 of the fixed mold 30. As a result, the injection opening 103 of the first straight portion 102 and the discharge opening 107 of the second straight portion 106 are exposed outside from the mold 20 (in this example embodiment, the fixed mold 30) (see FIG. 1).

[0039] Next, in the clamping step (step S30), as shown in FIG. 7, the movable mold 40 approaches the fixed mold 30 to close the mold 20. That is, the movable mold 40 is moved in a direction of arrow P1 in FIG. 7 to close the fixed mold 30. As a result, the molding space 50, in which the cast product 140 is to be molded, is defined by the cavity 31 of the fixed mold 30 and the core 41 of the movable mold 40. Before the movable mold 40 approaches the fixed mold 30, the slide portion 35 of the mold 20 (see also FIG. 1) is moved to be disposed inner to the main portion 110 of the pipe 100. In a state where the mold 20 is closed, the main portion 110 of the pipe 100 is not in contact with the fixed mold 30 or the movable mold 40. Only the first straight portion 102 and the second straight portion 106 of the pipe 100 are in contact with the mold 20 (in this example embodiment, the fixed mold 30).

[0040] Next, in the first filling step (step S40), the incompressible fluid (e.g., oil) is injected into the injection opening 103 of the first straight portion 102 to fill the third flow path 111 of the main portion 110. In more detail, as shown in FIG. 8, the transportation portion 82 of the fluid transporter 80 is attached to the first straight portion 102 of the pipe 100 by a one-touch joint or the like, and the recovery portion 84 of the fluid transporter 80 is attached to the second straight portion 106 of the pipe 100 by a one-touch joint or the like. The first flow path 104, the second flow path 108 and the third flow path 111 of the pipe 100 are filled with the incompressible fluid via the injection opening 103 from the fluid transporter 80. After the filling of the pipe 100 with the incompressible fluid is finished, the fluid transporter 80 may be detached from the pipe 100 or may be kept attached thereto. After the filling of the pipe 100 with the incompressible fluid is finished, the first pressing portion 38 presses the first straight portion 102 of the pipe 100 sideways and the second pressing portion 39 presses the second straight portion 106 of the pipe 100 sideways, and as a result, the first straight portion 102 and the second straight portion 106 are secured at the predetermined positions. In this example embodiment, the first filling step (step S40) is performed after the clamping step (step S30). Alternatively, the clamping step (step S30) may be performed after the first filling step (step S40).

[0041] Next, in the second filling step S50, the molding space 50 formed by the movable mold 40 and the fixed mold 30 is filled with a melted metal material. The metal material is, for example, an aluminum alloy. The melted metal material (molten metal) is injected into an injection opening (not shown) provided in the fixed mold 30 to fill the molding space 50. The melted metal material (molten metal) is cooled and thus coagulated in the mold 20. In this specification, the term “cooling” refers to cooling performed to coagulate the molten metal.

[0042] Next, in the discharge step (step S60), the incompressible fluid filling the third flow path 111 of the main portion 110 is discharged from the discharge opening 107 of the second straight portion 106 of the cast product 140. In more detail, as shown in FIG. 9, the fluid transporter 80 is driven to discharge the incompressible fluid from the discharge opening 107 of the second straight portion 106 of the pipe 100 toward the fluid transporter 80. The incompressible fluid discharged from the discharge opening 107 is recovered into the fluid transporter 80. After the incompressible fluid is discharged from the pipe 100, the fluid transporter 80 is detached from the pipe 100. The discharge step (step S60) is performed in a state where the cast product 140 is disposed in the mold 20. The discharge step (step S60) may be performed after the molten metal in the mold 20 is completely coagulated or in the middle of the molten metal being coagulated. That is, the discharge of the incompressible fluid may be started after a curing time (time required for the cooling performed to coagulate the molten metal) elapses or before the curing time elapses.

[0043] Next, in the extraction step (step S70), as shown in FIG. 10, the movable mold 40 is separated from the fixed mold 30 to open the mold 20. That is, the movable mold 40 is moved in a direction of arrow P2 in FIG. 10 to be separated from the fixed mold 30. At this point, the cast product 140 produced by molding is fixed to the movable mold 40. A core pin (not shown) is pressed onto the cast product 140 fixed to the movable mold 40 to extract the cast product 140, having the incompressible fluid already discharged from the third flow path 111 of the main portion 110 of the pipe 100, from the movable mold 40. In this manner, the cast product 140 including the pipe 100 and the metal material 120, which is cast with the pipe 100 disposed therein, is produced by molding.

[0044] As described above, according to the production method in this example embodiment, the incompressible fluid is injected into the injection opening 103 in a state where the pipe 100 is disposed in the mold 20, and after the molding space 50 is filled with the melted metal material, the incompressible fluid is discharged from the discharge opening 107 in a state where the pipe 100 is disposed in the mold 20. Thus, the incompressible fluid filling the third flow path 111 of the main portion 110 of the pipe 100 is discharged from the discharge opening 107 in a state where the cast product 140 is present in the mold 20. Therefore, the cast product 140 does not need to be set in a device for removing the incompressible fluid, and thus the time for producing the cast product 140 may be shortened. In the case where the cast product 140 is extracted from the mold 20 in a state where the third flow path 111 of the main portion 110 of the pipe 100 is filled with the incompressible fluid, there is an undesirable possibility that the incompressible fluid splatters outside through the injection opening 103 or the discharge opening 107 of the pipe 100. However, according to the above-described production method, the incompressible fluid has already been discharged when the cast product 140 is extracted from the mold 20. Therefore, there is no possibility that the incompressible fluid splatters outside.

[0045] According to the cast product production device 10 in this example embodiment, the fluid transporter 80 attached to the injection opening 103 and the discharge opening 107 of the pipe 100 disposed in the molding space 50 injects the incompressible fluid into the injection opening 103 and discharges the incompressible fluid from the discharge opening 107. Thus, the incompressible fluid may be discharged from the discharge opening 107 of the pipe 100 in a state where the pipe 100 is disposed in the mold 20. Therefore, the cast product 140 does not need to be set in a device for removing the incompressible fluid, and thus the time for producing the cast product 140 may be shortened. In addition, the relative positions of the fluid transporter 80 and the mold 20 is not changed whether the incompressible fluid may be injected into the injection opening 103 or discharged from the discharge opening 107. Therefore, the injection and the discharge of the incompressible fluid may be performed with high precision.

[0046] According to the mold 20 in this example embodiment, the main body 110 of the pipe 100 is not in contact with the fixed mold 30 or the movable mold 40 in a state where the first straight portion 102 of the pipe 100 is held by the first holding portion 32 and the second straight portion 106 of the pipe 100 is held by the second holding portion 36. Therefore, in a state where the molding space 50 is filled with the melted metal material, the metal material is cast with the entirety of the main portion 110 of the pipe 100 disposed therein. That is, in the produced cast product 140, the main portion 110 of the pipe 100 is not exposed outside.

[0047] According to the mold 20 in this example embodiment, the lengths of the first holding portion 32 and the second holding portion 36 are set such that in a state where the first straight portion 102 of the pipe 100 is held by the first holding portion 32 and the second straight portion 106 of the pipe 100 is held by the second holding portion 36, the first straight portion 102 and the second straight portion 106 are exposed outside. According to this example embodiment, the fluid transporter 80 may be easily attached to the first straight portion 102 and the second straight portion 106 exposed outside from the mold 20.

[0048] According to the mold 20 in this example embodiment, the fixed mold 30 including the first holding portion 32 and the second holding portion 36 includes the first pressing portion 38 pressing the first straight portion 102 sideways and the second pressing portion 39 pressing the second straight portion 106 sideways. According to this example embodiment, the first straight portion 102 and / or the second straight portion 106 of the pipe 100 may be secured to the predetermined position.

[0049] While example embodiments of the present invention have been described above, it is to be understood that variations and modifications will be apparent to those skilled in the art without departing from the scope and spirit of the present invention. The scope of the present invention, therefore, is to be determined solely by the following claims.

Examples

Embodiment Construction

[0024]Hereinafter, example embodiments of cast product production devices according to the present invention will be described with reference to the drawings. Note that the example embodiments described herein are not intended to limit the present invention. Elements and portions having the same functions are denoted by the same reference signs, and description for the same elements and portions will not be repeated or will be simplified as appropriate.

[0025]FIG. 1 is a schematic view of a cast product production device 10 according to this example embodiment. The cast product production device 10 uses a diecast method, that is, a casting method performed at a high speed and a high pressure. Herein, the term “high pressure” refers to, for example, 20 MPa to 100 MPa. The cast product production device 10 produces a cast product 140 (see FIG. 3) including a pipe 100 (see FIG. 2) and a metal material 120, which is cast with the pipe 100 disposed therein. The cast product production dev...

Claims

1-5 (canceled)6. A method for producing a cast product that includes a pipe including an injection opening into which an incompressible fluid is injected, a discharge opening from which the incompressible fluid is discharged, and a flow path located between the injection opening and the discharge opening to allow the incompressible fluid to flow therethrough, and a metal material that is cast with the pipe disposed therein, the method comprising:preparing a mold including a fixed mold and a movable mold movable to approach, or to be separated from, the fixed mold;disposing the pipe in the mold;causing the movable mold to approach the fixed mold to close the mold;injecting the incompressible fluid into the injection opening to fill the flow path with the incompressible fluid;filling a molding space formed by the movable mold and the fixed mold with a melted metal material;discharging the incompressible fluid in the flow path from the discharge opening; andseparating the movable mold from the fixed mold to open the mold and extracting the cast product having the incompressible fluid discharged from the flow path.

7. A cast product production device comprising:a mold including a fixed mold and a movable mold movable to approach, or to be separated from, the fixed mold, the mold being configured such that a pipe including a first straight portion that includes an injection opening into which an incompressible fluid is injectable, a second straight portion that includes a discharge opening from which the incompressible fluid is dischargeable, and a main portion that is located between the first straight portion and the second straight portion and includes a flow path through which the incompressible fluid is capable of flowing is in a molding space formed by the movable mold and the fixed mold; anda fluid transporter attachable to the injection opening and the discharge opening of the pipe in the molding space to inject the incompressible fluid into the injection opening and discharge the incompressible fluid from the discharge opening.

8. A mold comprising:a fixed mold; anda movable mold movable to approach, or to be separated from, the fixed mold;the mold being configured such that a pipe is in a molding space defined by the movable mold and the fixed mold, the pipe including a first straight portion that includes an injection opening into which an incompressible fluid is injectable, a second straight portion that includes a discharge opening from which the incompressible fluid is dischargeable and is parallel to the first straight portion, and a main portion that is located between the first straight portion and the second straight portion and includes a flow path through which the incompressible fluid is capable of flowing;the mold further comprising:a first holding portion through which the first straight portion is insertable, the first holding portion holding the first straight portion; anda second holding portion through which the second straight portion is insertable, the second holding portion holding the second straight portion.

9. The mold according to claim 8, wherein the first holding portion and the second holding portion are provided in the fixed mold or the movable mold.

10. The mold according to claim 8, wherein, in a state where the first straight portion of the pipe is held by the first holding portion and the second straight portion of the pipe is held by the second holding portion, a gap is provided between the main portion of the pipe and the fixed mold and between the main portion of the pipe and the movable mold.

11. The mold according to claim 8, wherein the first holding portion and the second holding portion have lengths such that, in a state where the first straight portion of the pipe is held by the first holding portion and the second straight portion of the pipe is held by the second holding portion, the first straight portion and the second straight portion are exposed outside from the mold.

12. The mold according to claim 8, wherein the fixed mold or the movable mold including the first holding portion and the second holding portion includes at least one of a first pressing portion pressing the first straight portion sideways and a second pressing portion pressing the second straight portion sideways.

Images