TWI695747B - Precision casting process capable of accelerating heat dissipation of concave part of shell mold - Google Patents

Abstract

This creation is a precision casting process, which includes the steps of sizing the sample mold, removing the sample mold, installing the shell mold, sand filling the box, casting, heat dissipation and demoulding of the shell mold; among them, the shell mold has recesses. In this creation, a heat dissipation hole is provided in the casing at the position corresponding to the concave portion of the shell mold in the shell mold installation step. Heat convection to dissipate heat, and solve the problem of shrinkage of the finished product caused by insufficient sand filling between the concave part of the shell mold and the box in the existing precision casting process, providing a cooling rate that can make the concave part of the shell mold and other parts of the shell mold Driven at the same time, the precision casting process that reduces the shrinkage of the finished product at the concave part of the shell mold and can accelerate the heat dissipation of the concave part of the shell mold is achieved.

Description

Precision casting process capable of accelerating heat dissipation of concave part of shell mold

This creation relates to casting, and in particular refers to a precision casting process that can reduce the chance of shrinkage of the casting in the concave part of the shell mold during casting and can accelerate the heat dissipation of the concave part of the shell mold.

Traditional casting methods use various heat-resistant materials such as metal, gypsum, ceramics, and sand to make molds. Castings made by traditional casting methods have limited precision and usually have rough surfaces; they are different from traditional casting methods. Casting method, precision casting can be used to make parts with thin walls, complex contours, and precise dimensions; existing precision casting processes include: injection wax parts, repair wax parts, wax group trees, wax tree dip, shell mold dewaxing , Shell mold sintering, shell mold casting, shell mold cooling, shell mold shock shell, casting cutting, grinding gate, and related post-processing.

The existing precision casting process needs to consider the shape and size of the castings produced when making shell molds and deciding the number of waxing layers of the wax tree, as well as the shell molds needed for shell mold dewaxing and shell mold casting steps The strength of the wax tree is generally about four to eight layers; however, as the size and weight of the casting increase, the thermal shock required by the shell mold and the pressure generated by the molten steel are also greater, when the molten steel conducts When the heat to the shell mold exceeds the limit value that the shell mold can withstand, the shell mold begins to soften and expands with the pressure generated by the molten steel to cause the expansion mold; in order to avoid the expansion mold of the shell mold when casting molten steel The problem is that after the shell mold is sintered and before the molten steel is cast, the shell mold will be placed into the box, and after the sand is filled between the shell mold and the box, the molten steel will be injected into the inside of the shell mold; however, such as As shown in FIGS. 7, 8 and 9, a shell mold 70 is provided with a recess 71; a set of boxes 90 is provided with a box bottom 91; when the shell mold 70 is placed in the set of boxes 90, the shell mold 70 The concave portion 71 faces the bottom 91 of the box 90 to form a space S. When sand is filled between the shell mold 70 and the box 90, it is not easy to be filled in the space S. After casting molten steel, the shell Where the mold 70 contacts the sand The heat can be dissipated by heat conduction. However, the concave portion 71 of the shell mold 70 surrounding the space S cannot be conducted through the sand to conduct heat dissipation, resulting in heat loss and heat collection in the space S. When steel When the liquid is cooled, the molten steel in the concave portion 71 will be cooled later than the molten steel in other parts of the shell mold 70, which may cause the problem of shrinkage holes H at the corners of the concave portion of the casting.

In order to solve the problem of shrinkage of the finished product caused by insufficient sand filling between the concave part of the shell mold and the box in the existing precision casting process, this creation proposes a precision casting process, which includes the steps of shell film installation and shell mold heat dissipation The heat dissipation holes are provided at the position of the casing corresponding to the concave part of the shell mold, and the heat convection type is used to provide heat dissipation for the concave part of the shell mold, which can drive the cooling rate of the concave part of the shell mold and other parts of the shell mold to be consistent, and reduce the finished product The purpose of creating an opportunity for shrinkage at the recess of the shell mold.

This creation is a precision casting process that can accelerate the heat dissipation of the concave part of the shell mold. It includes: sample mold dipping slurry: the same mold is soaked in the slurry and covered with the slurry, and then the sand is dipped, and the slurry and sand coated on the sample mold are formed A shell mold, wherein the shell mold includes more than one concave portion provided on the outer surface of the shell mold; the sample mold is removed: heating the sample mold together with the shell mold to melt the sample mold, leaving the shell mold ; Shell mold installation: put the shell mold into a set of boxes, the set of boxes includes a box body and at least one heat dissipation hole and at least one flange are provided at a position corresponding to at least one concave portion of the shell mold, the at least one convex The rim is located inside the casing and surrounds the at least one heat dissipation hole respectively; the casing sand filling: filling sand between the shell mold and the casing; casting: pouring molten steel into the shell mold; the shell mold heat dissipation: the At least one concave portion dissipates heat through the corresponding heat dissipation hole to allow the molten steel to cool to form a casting; and demolding: removing the casting from the shell mold.

The aforementioned precision casting process capable of accelerating the heat dissipation of the concave part of the shell mold, wherein the box body includes a peripheral wall, a box bottom and a plurality of supporting feet, the heat dissipation holes are penetrated through the box bottom of the box body, and the plurality of supporting feet It is arranged on the bottom of the box.

In the aforementioned precision casting process capable of accelerating the heat dissipation of the concave portion of the shell mold, the set of boxes includes a box body including a peripheral wall and a box bottom, and the heat dissipation holes are penetrated through the peripheral wall of the box body.

The aforementioned precision casting process capable of accelerating the heat dissipation of the concave part of the shell mold includes the step of supporting the concave part of the shell mold, each concave part of the shell mold includes a peripheral wall, and in the step of supporting the concave part of the shell mold, a peripheral wall support Placed in one of the recesses of the shell mold, the peripheral wall support member includes two opposite ends, each end of the peripheral wall support member has a gradually expanding cross section, and both ends of the peripheral wall support member abut against the peripheral wall of the recessed portion; Each concave portion of the shell mold includes a bottom surface, and in the shell mold concave portion supporting step, a bottom support member is further accommodated in the concave portion accommodating the peripheral wall support member, and the bottom support member includes a flat surface , The plane of the bottom support abuts against the bottom surface of the recess.

The aforementioned precision casting process capable of accelerating the heat dissipation of the concave part of the shell mold, wherein each concave part of the shell mold includes a bottom surface, and in the step of supporting the concave part of the shell mold, it is tied to the concave part accommodating the peripheral wall support A bottom support member is further accommodated. The bottom support member includes a plane, and the plane of the bottom support member abuts against the bottom surface of the recess.

The aforementioned precision casting process capable of accelerating the heat dissipation of the concave part of the shell mold, wherein the step of supporting the concave part of the shell mold is performed before the step of removing the sample mold.

The aforementioned precision casting process that can accelerate the heat dissipation of the concave part of the shell mold, wherein the step of supporting the concave part of the shell mold is performed after the step of removing the sample mold.

The efficiency gains achieved by the technical means of this creation are:

1. This creation of a precision casting process that can accelerate the heat dissipation of the concave part of the shell mold, between the sample mold removal step and the casting step, a shell mold installation step is added, which is placed on the casing of the box corresponding to the position of the concave part of the shell mold Heat dissipation holes, so that the concave part of the shell mold can use the heat dissipation holes for heat convection to dissipate heat in the concave part of the shell mold. Probability.

2. This creative system supports the concave part of the shell mold with a peripheral wall support. The peripheral wall support can provide support for the peripheral wall of the concave part, so that the peripheral wall of the concave part will not expand when casting.

3. This creation uses the bottom support to support the concave part of the shell mold. The bottom support uses the set plane to provide support for the bottom surface of the concave part, so that the bottom surface of the concave part will not expand the mold during casting. It also helps to improve the quality of castings.

S1: Prototype dip

S2: Sample removal

S3: Shell mold installation

S4: sand filling

S5: casting

S6: Shell mold heat dissipation

10: Shell mold

11: Room

12: recess

121: Perimeter wall

122: underside

20: Peripheral wall support

21: end

30: bottom support

40: set of boxes

41: cabinet

411: Perimeter wall

412: bottom of the box

42: Cooling hole

43: flange

44: Support feet

70: Shell mold

71: recess

90: set of boxes

91: bottom of the box

H: Shrinkage

S: Space

FIG. 1 is a flowchart of the first preferred embodiment of the present creation.

FIG. 2 is an implementation schematic diagram of the first preferred embodiment of the present creation.

FIG. 3 is an implementation schematic diagram of the first preferred embodiment of the present creation.

FIG. 4 is an implementation schematic diagram of the first preferred embodiment of the present creation.

FIG. 5 is an implementation schematic diagram of the second preferred embodiment of the present creation.

FIG. 6 is an implementation schematic diagram of the third preferred embodiment of the present creation.

Fig. 7 is an operation schematic diagram of the existing precision casting process.

Figure 8 is a schematic diagram of the operation of the existing precision casting process.

9 is a schematic diagram of the operation of the existing precision casting process.

In order to understand the technical features and practical effects of the present invention in detail, and can be implemented according to the content of creation, the preferred embodiments shown in the drawings are further described in detail below.

As shown in FIGS. 1 to 4, the first preferred embodiment of the precision casting process that can accelerate the heat dissipation of the concave part of the shell mold is to inject the sample mold after the injection of the sample mold, the repair of the sample mold, and the sample module tree. S1, sample removal S2, shell mold installation S3, box filling sand S4, casting S5 and shell mold heat dissipation S6, and demoulding steps.

Injection model: the model is made by pouring wax, plastic, mercury or foamed material. After the poured wax, plastic or mercury cools and solidifies to form the model, the model is taken out.

Refurbish the sample mold: remove the burrs of the sample mold or flatten the surface of the sample mold.

Sample mold dipping slurry S1: After washing the sample mold surface lightly, immerse the sample mold in the slurry including the binder and the refractory material to allow the slurry to adhere to the surface of the sample mold, and then carry out sand dipping, the slurry and the sand are dried to form a shell mold ; In the step of dip the slurry S1 of the sample, soak the sample repeatedly in the slurry and sand several times, in addition to uniformly attaching the slurry and sand to the surface of the sample, and also allowing the shell mold to have sufficient thickness.

Sample mold removal S2: heating the sample mold together with the shell mold to melt the sample mold and flow out, and leaving the shell mold.

As shown in FIG. 2, a shell mold 10 includes an outer surface, a chamber 11 and a recess 12. The chamber 11 is disposed inside the shell mold 10. The chamber 11 is used during the casting S5 step. To hold molten steel; the concave portion 12 is concavely provided on the outer surface of the shell mold 10, and the concave portion 12 includes a peripheral wall 121 and a bottom surface 122; in application, the outline of the shell mold 10 will be different according to different designs and even include There are a large number of the recesses 12, and the number and contour of the recesses 12 are not specifically limited in this creation; a set of boxes 40 includes a box 41.

Shell mold installation S3: In the shell mold installation step S3, a heat dissipation hole 42 is provided in the box 40 corresponding to the position of the recess 12 of the shell mold 10, and when the shell mold 10 is placed in the box 40, the The recess 12 is aligned with the heat dissipation hole 42 and communicates with the heat dissipation hole 42.

As shown in FIG. 2, the box 40 includes the heat dissipation hole 42, a flange 43 and a plurality of support legs 44; wherein the heat dissipation hole 42 is penetrated through the box 41; the flange 43 is located on the box 41 Inside and around the heat dissipation hole 42; the plurality of supporting feet 44 are arranged at the bottom of the box 41; in the first preferred implementation of this creation For example, the box 41 includes a peripheral wall 411 and a box bottom 412, the heat dissipation holes 42 are penetrated through the box bottom 412 of the box 41; the position and number of the heat dissipation holes 42 can correspond to the shell mold 10 The position and number of the recesses 12 are provided, and the position of the heat dissipation holes 42 can also be provided on the peripheral wall 411 of the box 41 corresponding to the position of the recess 12 of the shell mold 10.

Box sand filling S4: After the shell mold 10 is placed in the box body 41 of the box 40, as shown in FIG. 3, sand is filled between the shell mold 10 and the box body 41 of the box 40 to The filled sand supports the other parts of the shell mold 10.

Casting S5: As shown in FIGS. 3 and 4, molten steel is injected into the chamber 11 of the shell mold 10.

Shell mold heat dissipation S6: the concave portion 12 dissipates heat through the corresponding heat dissipation holes 42 and the molten steel is cooled in the chamber 11 of the shell mold 10 to form a casting; the second preferred embodiment of this creation is shown in FIG. The second preferred embodiment is substantially the same as the first preferred embodiment, and also includes sample mold dip S1, sample mold removal S2, shell mold installation S3, box sand filling S4, casting S5, shell mold heat dissipation S6, and Steps such as demoulding; the difference between the second preferred embodiment and the first preferred embodiment is that in the second preferred embodiment, the heat dissipation holes 42 of the box 40 correspond to the positions of the recesses 12 of the shell mold 10 In addition, it penetrates the peripheral wall 411 of the box 41.

The third preferred embodiment of this creation is substantially the same as the first and second preferred embodiments, and also includes sample mold dip S1, sample mold removal S2, shell mold installation S3, box sand filling S4, and casting S5 , Shell mold heat dissipation S6, and demoulding steps; the difference between the third preferred embodiment and the first and second preferred embodiments is that in the third preferred embodiment, it is based on the sample removal step S2 and Between the step S3 of installing the shell mold, the step of supporting the concave part of the shell mold is further arranged, as shown in FIG. 6, in the step of supporting the concave part of the shell mold, the peripheral wall support 20 and a bottom support 30 are accommodated and fixed to the In the concave portion 12 of the shell mold 10, the peripheral wall support 20 includes two opposite ends 21, each end of the peripheral wall support 20 has a gradually expanding cross section, and both ends 21 of the peripheral wall support 20 abut against the concave portion 12 Peripheral wall 121; the bottom support 30 supports the bottom surface 122 of the concave portion 12 with the set plane; the peripheral wall support 20 and the bottom support 30 can be fire-resistant Made of 1100°C refractory material, but not limited to this; in application, the number of the peripheral wall support 20 and the bottom support 30 can be set corresponding to the number of recesses 12, and this creation is for the peripheral wall support The structure and shape of the 20 and the bottom support 30 are not particularly limited, as long as the peripheral wall support 20 can resist the peripheral wall 121 of the recess 12 and the bottom support 30 can resist the bottom surface 122 of the recess 12 from the recess It is only necessary to provide a supporting effect for the concave portion 12 within 12.

The precision casting process of this creation can accelerate the heat dissipation of the concave portion of the shell mold. The heat dissipation holes 42 are provided on the peripheral wall or bottom of the casing 41 of the box 40 corresponding to the position of the concave portion 12 of the shell mold 10. The concave portion 12 can use the sleeve The heat dissipation holes 42 provided in the box 40 are used for heat convection and heat dissipation, which helps to make the temperature drop rate of the concave portion 12 of the shell mold 10 and each part of the shell mold 10 consistent. The shrinkage holes of the casting are usually generated by molten steel The slowest cooling place can reduce the chance of shrinkage of the casting by making the temperature of each part of the shell mold 10 decrease uniformly.

In addition, in this work, the peripheral wall support 20 supports the peripheral wall 121 of the recess 12. The peripheral wall support 20 can provide support to the peripheral wall 121 of the recess 12 of the shell mold 10 during the casting step S5 to avoid casting. The shell mold deforms due to the expansion of the mold; moreover, this creation supports the bottom surface 122 of the concave portion 12 with the bottom support 30, which can also prevent the casting from being deformed due to the expansion of the shell mold.

In the third preferred embodiment of the present invention, after the sample model is removed from the S2 step, the step of supporting the concave part of the shell mold is followed; in application, the peripheral wall can be supported before the sample model is removed from the S2 step. The piece 20 and the bottom support 30 are placed in the recess 12 to perform the shell mold recess support step, as long as the shell mold recess support step added in this creation can provide the recess 12 of the shell mold 10 when performing the casting S5 step The peripheral wall 121 and the bottom surface 122 are fully supported, and the expansion of the shell mold 10 can be avoided, which is the subject of protection for this creation.

Finally, the author can arrange the shell mold sintering step before the sample mold removal step S2 or after the sample mold removal step S2 to remove the moisture and other substances remaining in the shell mold 10 and improve the shell mold 10 Strength; preferably, the shell mold 10 can be provided with the peripheral wall support 20 and the bottom support 30 After the concave portion 12 is supported, and before the box sand filling step is performed, the shell mold 10 is sintered to avoid incomplete sintering of the shell mold.

S1 model slurries S2 model removal S3 shell model installation S4 model shell S4 model box sand filling S5 model casting

Claims (9)

A precision casting process capable of accelerating the heat dissipation of the concave part of the shell mold, which includes: sample mold dipping slurry: the same mold is soaked in the slurry and covered with the slurry, and then the sand is dipped, and the slurry and the sand coated on the sample mold form a shell Mold, wherein the shell mold includes more than one concave portion provided on the outer surface of the shell mold; the sample mold is removed: the sample mold is heated together with the shell mold to melt the sample mold, leaving the shell mold; the shell Mold installation: The shell mold is placed into a set of boxes, which includes a box body and at least one heat dissipation hole and at least one flange are provided at a position corresponding to at least one recess of the shell mold, the at least one flange is located at The box body surrounds the at least one heat dissipation hole; the box sand filling: filling sand between the shell mold and the box; casting: pouring molten steel into the shell mold; shell mold heat dissipation: the at least one concave part passes through The corresponding heat dissipation holes dissipate heat to allow the molten steel to cool to form a casting; and demolding: the casting is removed from the shell mold. The precision casting process capable of accelerating the heat dissipation of the concave part of the shell mold as described in claim 1, wherein the box body includes a peripheral wall, a box bottom and a plurality of supporting feet, and the heat dissipation holes are provided in the box bottom of the box body , The plural supporting feet are arranged on the bottom of the box. The precision casting process capable of accelerating the heat dissipation of the concave part of the shell mold as described in claim 1, wherein the sleeve box includes a box body including a peripheral wall and a box bottom, and the heat dissipation holes are penetrated through the The peripheral wall of the box. The precision casting process capable of accelerating the heat dissipation of the concave part of the shell mold as described in claim 2 or 3 includes a step of supporting the concave part of the shell mold, each concave part of the shell mold includes a peripheral wall, and in the step of supporting the concave part of the shell mold , A peripheral wall support is accommodated in one of the recesses of the shell mold, the peripheral wall support includes two opposite ends, each end of the peripheral wall support has a gradually expanding cross section, and both ends of the peripheral wall support Leaning against the peripheral wall of the concave portion; each concave portion of the shell mold includes a bottom surface, and in the step of supporting the concave portion of the shell mold, a bottom support member is further accommodated in the concave portion accommodating the circumferential wall support member The bottom support member includes a flat surface, and the flat surface of the bottom support member abuts against the bottom surface of the recess. The precision casting process capable of accelerating the heat dissipation of the concave part of the shell mold according to claim 4, wherein the step of supporting the concave part of the shell mold is performed before the step of removing the sample mold. The precision casting process capable of accelerating the heat dissipation of the concave part of the shell mold as described in claim 4, wherein the step of supporting the concave part of the shell mold is performed after the step of removing the sample mold. According to claim 2 or 3, the precision casting process capable of accelerating the heat dissipation of the concave part of the shell mold includes a step of supporting the concave part of the shell mold, each concave part of the shell mold includes a bottom surface, and in the step of supporting the concave part of the shell mold, A bottom support is accommodated in one of the recesses of the shell mold. The bottom support includes a flat surface, and the flat surface of the bottom support abuts against the bottom surface of the recess. The precision casting process capable of accelerating the heat dissipation of the concave part of the shell mold according to claim 7, wherein the step of supporting the concave part of the shell mold is performed before the step of removing the sample mold. The precision casting process capable of accelerating the heat dissipation of the concave part of the shell mold as described in claim 7, wherein the step of supporting the concave part of the shell mold is performed after the step of removing the sample mold.

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