Mold, casting method, method for manufacturing component of compressor, method for manufacturing compressor, method for manufacturing air conditioner, and original mold of mold

Abstract

A mold (10) comprises: a sand mold (11) having a cavity part (19) for trapping gas; and a core (17) having a core-securing core print part (18) for securing the core to the sand mold (11). The core-securing core print part (18) has a discharge surface (18a) that is adjacent to the cavity part (19) and discharges gas to the cavity part (19). An end section of the discharge surface (18a) contacts the sand mold (11) and is disposed in a closed space surrounded by the sand mold (11).

Description

Mold, casting method, method for producing compressor part, method for producing compressor, method for producing air conditioning apparatus, and original pattern of mold

[0001] The present disclosure relates to a mold, a casting method, a method for producing a compressor part, a method for producing a compressor, a method for producing an air conditioning apparatus, and an original pattern of a mold.

[0002] In casting of metal parts, a core is used to provide a cavity in the metal part. In metal parts produced by casting, gas defects may occur due to gas entrainment by molten metal, moisture gas generated by evaporation of moisture in the mold, or gas generated by volatilization of a binder used for binding core sand mixing into the interior of the metal part. Gas defects may degrade mechanical properties including strength and elongation of cast metal parts. When a metal part is used as a component of a compressor mounted in an air conditioning apparatus, it may lead to refrigerant leakage.

[0003] As an example of countermeasures against gas defects, Patent Document 1 discloses a continuous casting method in which, in vertical continuous casting where pouring into a mold is performed after a core is assembled to a main mold, a cavity extending to the tip side of a core supporting skirting board is formed when molding the main mold, a communication hole that communicates the cavity with the outside of the main mold is drilled, then pouring into the main mold is performed, and gas accumulated in the cavity is forcibly sucked and discharged from the communication hole.

[0004] Japanese Unexamined Patent Publication No. Hei 5-000356

[0005] In vertical continuous casting of a horizontally split mold with upper and lower molds, the horizontal direction of the core fixing baseboard is perpendicular to the mold removal direction. Therefore, it is difficult to form a gas discharge cavity in the horizontal direction of the core fixing baseboard, and it is necessary to provide a gas discharge cavity in the vertical upper part of the core fixing baseboard. However, if a cavity with the same cross-sectional area as the core fixing baseboard described in Patent Document 1 is provided in the upper part of the core fixing baseboard, the contact area between the core fixing baseboard and the sand decreases, and the load of sand on the upper part of the core fixing baseboard decreases. As a result, the fixing of the core weakens, causing the core to move during pouring, and product shape defects are more likely to occur. In addition, when providing the above-mentioned communication hole, it is necessary to either drill it after the sand mold is made as described in Patent Document 1, or to provide an elongated convex shape for creating the communication hole in the wooden mold. The former increases the number of man-hours, while the latter increases mold wear, mold removal difficulty, and mold storage space.

[0006] This disclosure was devised to solve the above-mentioned problems and aims to provide a mold, a casting method, a method for manufacturing compressor parts, a method for manufacturing a compressor, a method for manufacturing air conditioning equipment, and a mold prototype that suppresses product shape defects and gas defects.

[0007] To achieve the above objective, the mold according to this disclosure comprises a sand mold having a cavity for trapping gas, and a core having a core fixing base plate for fixing to the sand mold, wherein the core fixing base plate is adjacent to the cavity and has a discharge surface for releasing gas into the cavity, and the end of the discharge surface is in contact with the sand mold.

[0008] According to this disclosure, the core fixing base plate is adjacent to the cavity and has a discharge surface for releasing gas into the cavity, and the end of the discharge surface is in contact with the sand mold, thereby making it possible to suppress product shape defects and gas defects.

[0009] A bottom view of a compressor support part according to Embodiment 1 of this disclosure. A top view of a compressor support part according to Embodiment 1 of this disclosure. This is a cross-sectional view taken along III-III in Figure 1. A cross-sectional view of a mold according to Embodiment 1 of this disclosure. A top view showing the upper mold according to Embodiment 1 of this disclosure. A top view showing the lower mold according to Embodiment 1 of this disclosure. A top view showing the core fixing base plate and cavity according to Embodiment 1 of this disclosure. A side view showing the core fixing base plate and cavity according to Embodiment 1 of this disclosure. A flowchart showing the casting method according to Embodiment 1 of this disclosure. A partial top view showing the prototype according to Embodiment 1 of this disclosure. A partial side view showing the prototype according to Embodiment 1 of this disclosure. A top view showing the core fixing base plate and cavity according to Embodiment 2 of this disclosure. A side view showing the baseboard portion and hollow portion for fixing the core, according to Embodiment 3 of this disclosure. A top view showing the baseboard portion and hollow portion for fixing the core, according to Embodiment 3 of this disclosure. A side view showing the baseboard portion and hollow portion for fixing the core, according to Embodiment 4 of this disclosure. A cross-sectional view showing the mold, according to Embodiment 5 of this disclosure. A cross-sectional view showing the hollow member, according to Embodiment 5 of this disclosure. A cross-sectional view showing the hollow member, according to Embodiment 6 of this disclosure. A cross-sectional view showing the hollow member, according to Embodiment 6 of this disclosure. A cross-sectional view showing the hollow member, according to Embodiment 7 of this disclosure. A diagram showing the core and hollow member, according to Embodiment 8 of this disclosure.

[0010] (Embodiment 1) Hereinafter, a mold, casting method, manufacturing method for compressor parts, and prototype of the mold relating to an embodiment for implementing the present disclosure will be described with reference to the drawings.

[0011] Embodiment 1 describes a mold for manufacturing a compressor support component mounted on a scroll compressor used in air conditioning equipment by casting. This mold comprises an upper mold and a lower mold, and the split surface is horizontal. In this example, a horizontally split mold is described, but depending on the casting method, it may also be manufactured using a vertically split mold. Here, the case of casting a compressor support component is described, but it is possible to cast other compressor parts or parts of products other than compressors in the same manner.

[0012] First, the configuration of the compressor support component 100 will be described with reference to the drawings. As shown in Figures 1 to 3, the compressor support component 100 is cylindrical in shape with a stepped surface in the Z direction and has one or more air intakes, which are voids 110. As shown in Figure 3, the void 110 has an inner diameter that is larger than the inner diameter of the side wall 130, with the stepped intermediate surface 120 as the reference, and is composed of a void that penetrates in the Z direction. This void 110 overlaps with the stepped intermediate surface 120 in the same area, and a void remains on the stepped intermediate surface 120 as well. During manufacturing, the void 110 is formed using a core 17, which will be described later in Figure 4. Note that a Cartesian coordinate system is set up with the axial direction of the compressor support component 100 being the Z direction, the direction connecting the voids 110 being the X direction, and the direction perpendicular to the X and Z directions being the Y direction, and will be referenced as appropriate.

[0013] Next, the mold for casting the compressor support component 100 according to Embodiment 1 will be described in detail. As shown in Figure 4, the mold 10 comprises a sand mold 11 for casting the compressor support component 100 and a core 17 for forming the two void portions 110 of the compressor support component 100. The sand mold 11 also comprises an upper mold 11a and a lower mold 11b.

[0014] The sand mold 11 includes a sprue section 12 for introducing molten metal, a runner section 13 through which the introduced molten metal flows, a riser section 14 to prevent shrinkage defects in the product cavity section 16, a weir section 15 connecting the riser section 14 and the product cavity section 16, a product cavity section 16 having the shape of the compressor support part 100, and a cavity section 19 for trapping gas generated during casting. With this configuration, the compressor support part 100 is cast by sequentially flowing and filling the product cavity section 16 from the sprue section 12. The cavity section 19 is surrounded by an inner wall that does not come into contact with the outside of the mold 10. Since the density of ammonia gas or water vapor, which are the main components of the gas generated during casting, is lower than that of the atmosphere and tends to accumulate at the top, it is preferable to provide the cavity section 19 above the core fixing baseboard section 18, which will be described later. Furthermore, by providing a cavity 19 at the lower part of the core fixing baseboard section 18, it is possible to trap carbon dioxide, which has a higher specific gravity than the atmosphere.

[0015] The core 17 is used to form the void 110 and has a core fixing base plate 18 provided for fixing the core 17 to the sand mold 11. Molten metal does not flow into the core 17, and the void is formed. The core fixing base plate 18 also has a discharge surface 18a that releases gas generated from the core 17 into the cavity 19.

[0016] As shown in Figures 5 and 6, three product cavities 16 are configured inside a single mold 10, and three compressor support parts 100 are manufactured in a single casting. Each product cavity 16 has two voids 110 to be formed, and each core fixing baseboard 18 has a cavity 19 above it. One core 17 is formed for each void 110. In this example, one core 17 is used for each void 110, but multiple voids 110 may be created using a single core 17, such as a crescent shape or an annular shape.

[0017] Next, the core 17 and the cavity 19 will be described. As shown in Figure 7, the cavity 19 is rectangular when viewed from the Z direction. The area of ​​the discharge surface 18a of the core fixing base plate 18 is larger than the cross-sectional area of ​​the cavity 19 in the XY section. As a result, when viewed from the Z direction, the end 18b of the discharge surface 18a protrudes from the cavity 19, and as shown in Figure 8, the end 18b of the discharge surface 18a contacts the sand mold 11. Specifically, by forming the discharge surface 18a to be longer in the X direction than the cavity 19, it is possible to increase the contact area between the end 18b of the discharge surface 18a of the core fixing base plate 18 and the sand mold 11. This firmly fixes the core 17 to the sand mold 11 and prevents product shape defects caused by the movement of the core 17. Furthermore, the cavity 19 does not communicate with the outside and is located in a closed space surrounded by the sand mold 11. It is composed of a columnar shape extending in the Z direction and is tapered for mold removal. The cavity 19 may also be composed without a taper. It is also preferable that the adjacent portion of the discharge surface 18a of the core fixing base plate 18 for fixing to the sand mold 11 and the cavity 19 adjacent to the discharge surface 18a are not similar in shape. This strengthens the fixing of the core 17. In this example, the cavity 19 is located vertically above the core fixing base plate 18. This allows the gas generated during casting to be easily trapped in the cavity 19 if it is light. Alternatively, the cavity 19 may be located vertically below the core 17 having the core fixing base plate 18. This allows the gas generated during casting to be easily trapped in the cavity 19 if it is heavy.

[0018] Next, a casting method for casting a casting using the mold 10 described above will be explained. Here, an example of manufacturing a compressor support part 100 will be described, but the same casting method can be used when casting other parts of the compressor or parts of products other than compressors.

[0019] As shown in Figure 9, the casting method comprises a mold manufacturing step (step S101) for manufacturing a mold 10, a casting step (step S102) for introducing molten metal into the mold 10, and a removal step (step S103) for removing the casting from the mold 10 into which the molten metal was introduced in the casting step (step S102). The method for manufacturing compressor parts is to manufacture compressor parts using this casting method. Compressor parts are compressor support parts 100 and parts used in the compressor other than the compressor support parts 100. The method for manufacturing a compressor is to manufacture a compressor using the cast parts manufactured by the method for manufacturing compressor parts. The method for manufacturing air conditioning equipment is to manufacture air conditioning equipment equipped with a compressor manufactured by the method for manufacturing a compressor.

[0020] In the mold manufacturing process (step S101), the mold 10 shown in Figure 4 is manufactured. The prototype for manufacturing the mold 10 includes a void for arranging the runner section 13, the riser section 14, the weir section 15, the product cavity section 16, and the core fixing base section 18, and a protrusion for forming a gas trapping cavity 19. In detail, as shown in Figures 10 and 11, the prototype 30 includes a first protrusion 31 that forms a void for arranging the core fixing base section 18, and a second protrusion 32 connected to the first protrusion 31 that forms the gas trapping cavity 19. Also, when viewed from the Z direction, which is the demolding direction, the end 33 of the first protrusion 31 protrudes beyond the second protrusion 32. By using this prototype 30, a mold 10 can be easily manufactured that includes a void for arranging the runner section 13, the rising molten metal section 14, the weir section 15, the product cavity section 16, and the core fixing baseboard section 18, as well as a hollow section 19. The second protrusion 32 that forms the hollow section 19 is configured to be smaller than the first protrusion 31 that forms the void for arranging the core fixing baseboard section 18. As a result, the hollow section 19 is configured to be shorter in the Y direction and longer in the X direction. That is, the contact area between the mold 10 and the core fixing baseboard section 18 is increased in the Y direction, and the contact area between the mold 10 and the core fixing baseboard section 18 is reduced in the X direction. The second protrusion 32 that forms the hollow section 19 is manufactured with a taper. However, if it is not necessary, it may be manufactured without a taper.

[0021] The prototype 30 is made of a metal component including iron, aluminum, and copper so as to withstand the pressure during mold molding. The prototype 30 has protrusions that form the riser portion 14. Furthermore, when viewed from a direction perpendicular to the demolding direction, it is preferable that the second protrusion 32 that forms the cavity portion 19 is lower in height than the protrusion that forms the riser portion 14. This prevents an increase in the area of ​​the mold storage space. Depending on the number of shots, the prototype 30 may be made of wood or resin. In Embodiment 1, the case with two void portions 110 was given as an example, but the number of void portions 110 may be one, three, or more. In that case, the cavity portion 19 is formed and constructed on the upper part of each core fixing base plate portion 18. In addition, in Embodiment 1, the case with three compressor support parts 100 being manufactured at once was given as an example, but depending on the size, one, two, or four or more may be manufactured.

[0022] In the casting process (step S102), molten metal is introduced into the sprue 12 of the mold 10. The molten metal then passes through the runner 13, riser 14, and weir 15 before being introduced into the product cavity 16. Gas generated during casting is trapped in the cavity 19, thus suppressing gas defects. Afterward, the mold 10 and the molten metal are cooled.

[0023] In the removal process (step S103), the castings that have been cast into the product cavity 16 are removed from the mold 10. The sand adhering to the removed castings is removed, and the casting method is completed.

[0024] As described above, according to the first embodiment of the mold 10, the core fixing base plate 18 is adjacent to the cavity 19 and has a discharge surface 18a that releases gas into the cavity 19, and the end 18b of the discharge surface 18a is in contact with the sand mold 11, thereby making it possible to suppress product shape defects and gas defects. In detail, since ammonia gas or water vapor, which are the main components of the gas generated during casting, have a low specific gravity and tend to accumulate at the top, the cavity 19 is provided above the core fixing base plate 18, which will be described later, making it possible to trap the gas during casting. In addition, by increasing the contact area between the end 18b of the discharge surface 18a of the core fixing base plate 18 of the core 17 and the sand mold 11, it is possible to strengthen the fixing of the core 17. Furthermore, by providing a second protrusion 32 that forms the cavity 19 in the original model 30 for manufacturing the mold 10, it is possible to integrally mold the mold 10 during main mold molding. In addition, the prototype 30 is provided with a second protrusion 32 that forms a cavity 19, and the second protrusion 32 is configured to be lower in height than the protrusion that forms the riser 14, and by maximizing the cross-sectional area, it is possible to solve problems such as increased man-hours, mold wear, die-cutting performance, and mold storage space.

[0025] (Embodiment 2) In the above embodiment, the case in which the cavity 19 is rectangular has been described. However, in the case of a rectangle, when the cavity 19 is molded into the mold and then removed, the corners can cause resistance and snag, potentially damaging the mold 10. For this reason, the cavity 19 may have a columnar shape with an oval bottom, including an elliptical column, as shown in Figures 12 and 13. The oval shape includes circular, elliptical, oblong, or egg shapes. By doing so, it is possible to reduce resistance during removal and reduce damage to the mold during removal.

[0026] (Embodiment 3) Embodiments 1 and 2 described the case in which the cavity 19 has a columnar shape. However, in the case of a columnar shape, when the cavity 19 is molded into the mold and then removed, the corners at the top of the columnar shape may catch on the mold, potentially damaging the mold. The cavity 19 may have a conical shape, as shown in Figures 14 and 15. By making the cavity 19 conical, it is possible to reduce the resistance during removal and reduce damage to the mold during removal. In addition, the apex portion 20 of the conical shape may be rounded. This further reduces the resistance during removal. Note that, while maintaining the conical shape, the shape viewed from the Z direction may be oval, as in Embodiment 2.

[0027] (Embodiment 4) As shown in Figure 16, the mold 10 according to Embodiment 4 is provided with a gas vent hole 21 that communicates with the outside at the upper part of the upper mold 11a, in addition to the features of Embodiment 1, at the top of the core fixing baseboard 18. This provides a further reduction in gas defects. The sand mold 11 has a sprue section 12 and a runner section 13 as inflow paths for molten metal, and a riser section 14 to prevent shrinkage defects in the product cavity section 16. The riser section 14 and the product cavity section 16 are connected by a weir section 15, and the compressor support part 100 is manufactured by sequentially flowing and filling the product cavity section 16 from the sprue section 12. The core 17 is used to form the two void sections 110 of the compressor support part 100, and molten metal does not flow into the core 17, so the void sections are formed. The core fixing baseboard 18 is provided to fix the core 17 to the sand mold 11. A cavity 19 is formed in the upper part of the core fixing baseboard 18 in the Z direction. In addition, a gas vent hole 21 is provided above the cavity 19 at the upper end of the upper mold 11a, connecting the cavity 19 to the outside. The shape of the cavity 19 may be rectangular, oval, or conical.

[0028] (Embodiment 5) In Embodiment 5, as shown in Figure 17, the mold 10 may have a hollow member 22 for trapping gas placed above the core fixing baseboard 18 in Embodiment 1. This strengthens the fixing of the core 17 while reducing gas defects. This makes it possible to suppress product shape defects and gas defects. The sand mold 11 has a sprue section 12 and a runner section 13 as inflow paths for molten metal, and a riser section 14 to prevent shrinkage defects in the product cavity section 16. It is composed of a weir section 15 connecting the riser section 14 and the product cavity section 16, and the compressor support part 100 is manufactured by sequentially flowing and filling the product cavity section 16 from the sprue section 12. The core 17 is used to form the two intake ports of the compressor support part 100, and a core fixing baseboard 18 is provided for fixing it to the mold 10. A hollow member 22 having a contact area equivalent to that of the core fixing baseboard portion 18 is provided on the upper part of the core fixing baseboard portion 18. The core fixing baseboard portion 18 is adjacent to the hollow member 22 and has a discharge surface 18a for releasing gas into the hollow member 22. The prototype for manufacturing the mold 10 according to Embodiment 5 is the same as that of Embodiment 1. The mold 10 according to Embodiment 5 can be manufactured by fitting the hollow member 22 into the cavity portion 19 which was formed in the mold for manufacturing the mold according to Embodiment 1.

[0029] As the hollow member 22, a member having a porous cavity as shown in Figure 18 is used. The member having a porous cavity is composed of a fixed material portion 23 and a porous portion 24 that serves as a gas venting cavity. The hollow member 22 may also contain a gas adsorption component. In addition to a rectangular and columnar member as in Embodiment 1, the shape of the porous member may also be one with an oval bottom or a conical shape in the Z direction. As shown in Embodiment 4, a gas venting hole may be provided at the top of the hollow member 22, connecting the hollow member 22 to the outside at the top end of the mold.

[0030] (Embodiment 6) In Embodiment 5, the case in which the hollow member 22 is a member having a porous cavity was described. However, in members having a porous cavity, the cavity portion is independent, so the gas defect reduction effect may not be sufficient. Therefore, in order to further enhance the gas defect reduction effect, the porous cavity may be made into a pipe-shaped cavity, as shown in Figure 19. In this case, the hollow member 22A comprises a material portion 23 and a hollow pipe portion 25. This makes it possible to suppress gas defects even more strongly. The structure of the pipe portion 25 is not limited to a cylindrical cavity, but may also be a rectangular or oval-shaped cavity. Also, as shown in Figure 20, the hollow member 22B may have a honeycomb structure comprising a hollow polygonal prism 26. By doing so, it is possible to maximize the cavity volume while maintaining strength, and to achieve an even stronger gas defect suppression effect. In addition, the material portion 23 of the hollow members 22, 22A, and 22B may contain an adsorbent component that adsorbs gas. Furthermore, the shape of the hollow members 22, 22A, and 22B may be not limited to rectangular and columnar members, but may also be those with an oval-shaped base or a conical shape in the Z direction. As shown in Embodiment 4, gas vents may be provided at the top of the hollow members 22, 22A, and 22B, connecting the hollow members 22, 22A, and 22B to the outside at the top end of the mold.

[0031] (Embodiment 7) Embodiments 5 and 6 described the cases where the cavity of the hollow member 22 is porous, the cavity of the hollow member 22A is pipe-shaped, or the structure of the hollow member 22B is honeycomb. However, in the porous, pipe-shaped, and honeycomb structures, as shown in Figures 18 to 20, the volume of the cavity is reduced due to the presence of a contact surface 27 with the mold 10, and walls 28 that divide the pores and pipes extending in the Z direction of the hollow members 22A and 22B, so the gas defect reduction effect may not be fully realized. Therefore, as shown in Figure 21, in order to eliminate the contact surface 27 and walls 28, the hollow member 22C has a truss structure with beams 29, which maximizes the cavity volume while maintaining the fixing force of the core 17, thereby maximizing the gas defect reduction effect and the shape defect suppression effect. The thickness and number of framework members of the truss structure may be changed depending on the sand mold size. Furthermore, the shape of the truss-like member may not be limited to rectangular and columnar members as in Embodiment 1, but may also be an oval-shaped member or a conical member in the Z direction. In addition, the beam 29 of the hollow member 22C may contain an adsorbent component that adsorbs gas. As shown in Embodiment 4, a gas vent hole may be provided at the top of the hollow member 22C, connecting the hollow member 22C to the outside at the upper end of the mold.

[0032] (Embodiment 8) In Embodiment 5, a method for manufacturing a compressor support part 100 was described using a mold configured to cast a hollow member 22 on a core fixing baseboard 18. However, in Embodiment 5, since the core 17 and the hollow member 22 are separate, a thin gap is created between them, which reduces the fixing effect. In addition, since the mold is constructed by fitting two hollow members 22 into the gap and then fitting one core 17, there is a problem of increased man-hours. To further increase the fixing force of the core 17 while reducing the gas defect effect, it is preferable to use a mold 10 that uses a core 17 in which the hollow member 22 is fixed to the core fixing baseboard 18. Furthermore, while Embodiment 8 uses the porous hollow member 22 shown in Embodiment 5 as an example, a hollow member 22A having a hollow pipe section 25 as shown in Embodiment 6, a hollow member 22B having a hollow polygonal column 26, or a hollow member 22C having a truss structure with a beam 29 as shown in Embodiment 7 may also be used. In addition, as shown in Embodiments 6 and 7, any of the hollow members 22, 22A, 22B, or 22C may be rectangular and columnar in shape, or may have an oval bottom or a conical shape in the Z direction. Moreover, as shown in Embodiment 4, a gas vent hole connecting to the outside of the mold 10 may be provided at the top of the hollow member.

[0033] In Embodiment 8, as shown in Figure 22, a core 17 is used in which a hollow member 22 for trapping gas is fixed to a core fixing baseboard 18. This hollow member 22 has the same configuration as the hollow member 22 used in Embodiment 5. By manufacturing the mold 10 using a core 17 in which the hollow member 22 is fixed to the core fixing baseboard 18, it is possible to manufacture a mold 10 with a gas defect reduction effect and strengthened fixing force of the core 17 more easily than in Embodiment 5. This makes it possible to suppress product shape defects and gas defects. In addition, hollow members 22A, 22B, and 22C may be used instead of the hollow member 22. Furthermore, the shape of the porous member may be not only rectangular and columnar, but also one with an oval bottom or a cone shape in the Z direction. In addition, as shown in Embodiment 4, a gas vent hole connecting to the outside of the mold 10 may be provided at the top of the hollow member 22.

[0034] This disclosure allows for various embodiments and modifications without departing from the broad spirit and scope of this disclosure. Furthermore, the embodiments described above are for illustrative purposes only and do not limit the scope of this disclosure. In other words, the scope of this disclosure is indicated by the claims, not by the embodiments. Various modifications made within the scope of the claims and the equivalent significance of the disclosure are considered to be within the scope of this disclosure.

[0035] This application is based on Japanese Patent Application No. 2025-039627, filed on 12 March 2025. The entire specification, claims, and drawings of Japanese Patent Application No. 2025-039627 are incorporated herein by reference.

[0036] 10...Mold, 11...Sand mold, 11a...Upper mold, 11b...Lower mold, 12...Spring section, 13...Runner section, 14...Rising section, 15...Weir section, 16...Product cavity section, 17...Core, 18...Core fixing baseboard section, 18a...Discharge surface, 18b...End section, 19...Cavity section, 20...Apex section, 21...Vent hole, 22, 22A, 22B, 22C...Hollow member, 23...Material section, 24...Porous section, 25...Pipe section, 26...Polygonal prism, 27...Contact surface, 28...Wall section, 29...Beam, 30...Prototype, 31...First protrusion, 32...Second protrusion, 33...End section, 100...Compressor support part, 110...Gap section, 120...Intermediate surface, 130...Side wall

Claims

1. A mold comprising: a sand mold having a cavity for trapping gas; and a core having a core fixing base section for fixing the core to the sand mold, wherein the core fixing base section is adjacent to the cavity and has a discharge surface for releasing the gas into the cavity, and the end of the discharge surface is in contact with the sand mold and is positioned in a closed space surrounded by the sand mold.

2. The mold according to claim 1, wherein the adjacent portion of the core fixing base plate for fixing to the sand mold and the adjacent portion of the cavity adjacent to the core are not similar in shape.

3. A mold comprising: a sand mold having a hollow member for trapping gas; and a core having a core fixing baseboard for fixing the core to the sand mold, wherein the core fixing baseboard is adjacent to the hollow member and has a discharge surface for releasing the gas into the hollow member.

4. The mold according to claim 1, wherein the cavity has a columnar shape with a rectangular or oval bottom, or a conical shape.

5. The mold according to claim 1, wherein the cavity is located vertically above the baseboard portion for fixing the core.

6. The mold according to claim 1, wherein the core having the baseboard portion for fixing the core has the cavity portion located vertically below the core.

7. The mold according to claim 1, wherein the sand mold is provided with a gas vent hole that connects the cavity to the outside.

8. The mold according to claim 3, wherein the sand mold is provided with a gas vent hole that connects the hollow member to the outside.

9. The mold according to claim 3, wherein the hollow member is fixed to the baseboard portion for fixing the core.

10. The mold according to claim 3, wherein the hollow member has a porous cavity or a pipe-shaped cavity.

11. The mold according to claim 3, wherein the hollow member has a honeycomb structure comprising hollow polygonal columns or a truss structure comprising beams.

12. A casting method comprising: a casting step of introducing molten metal into a mold according to claim 1 or 3; and a removal step of removing a casting from the mold into which the molten metal was introduced in the casting step.

13. A method for manufacturing compressor parts, comprising manufacturing compressor parts by the casting method described in claim 12.

14. A method for manufacturing a compressor, comprising manufacturing a compressor using cast parts manufactured by the method for manufacturing compressor parts described in claim 13.

15. A method for manufacturing air conditioning equipment, comprising manufacturing air conditioning equipment equipped with a compressor manufactured by the method for manufacturing a compressor described in claim 14.

16. A mold prototype comprising: a first protrusion that forms a gap for arranging a baseboard for fixing the core; and a second protrusion connected to the first protrusion that forms a cavity for trapping gas, wherein, when viewed from the demolding direction, the end of the first protrusion protrudes beyond the second protrusion.

17. The mold prototype according to claim 16, further comprising a protrusion for forming a riser portion, wherein, when viewed from a direction perpendicular to the demolding direction, the second protrusion is lower in height than the protrusion for forming the riser portion.

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