KR100945896B1 - Mold manufacturing method for castings of impeller, mold using thereof and impeller manufactured thereby - Google Patents

Abstract

PURPOSE: A method of manufacturing a casting mold for an impeller and the impeller manufactured thereby are provided to improve a workability for manufacturing the mold by successively arranging a covering bottom core using a guide plate installed in a central bottom core. CONSTITUTION: A method of manufacturing a casting mold for an impeller comprises the following steps of: spreading a floor sand(111) in the inside of a lower bottom frame; preparing a wooden pattern matching a lower center side of an impeller to form a central bottom core with a cavity; forming the central bottom core on the floor sand inside the lower bottom frame using the wooden pattern; preparing a covering bottom core(122) in multiple pieces to arrange in the outside of the central bottom core; and completing the bottom core by arranging the covering bottom core around the outside of the central bottom core.

Description

Manufacturing method for castings of impeller, mold using same, and impeller manufactured by using same

The present invention relates to a mold for casting an impeller, and more particularly, a manufacturing method of a casting mold for manufacturing a casting of a large and complex part, such as a ship impeller, a mold manufactured by using the same and such a mold It relates to an impeller made from.

Generally, molds are divided into sand molds and metal molds according to the mold material. Here, the sand mold may be classified into a green mold and a dry sand mold according to the moisture state, and there are special molds.

Since the raw mold is melted in a state containing moisture at the time of making the mold, pores are likely to occur due to the generation of water vapor and poor air permeability, and the mold is damaged due to the low strength of the mold. Due to this, the material of the casting is likely to be nonuniform. The green mold is particularly unsuitable for casting materials with high injection temperatures and high shrinkage, such as cast steel.

On the other hand, the drying mold is a mold that is dried after the mold is manufactured, and has less water vapor generation, good air permeability, less porosity, and a large pressure casting mold due to the high strength of the mold. Suitable for Therefore, for large and complex castings, such as ship impellers, it can be said that the drying type is suitable for the death penalty.

1 is a perspective view showing an example of a casting for a large and complex impeller as described above.

Referring to the drawings, the impeller 1 includes a plurality of blades 2 having a spiral shape and having a cross-sectional thickness, and an annular rim 3 connecting the outer angles of the blades 2. Equipped. And the central hole is formed with a shaft hole (4) for coupling with the rotating shaft (not shown), the boss portion (5) for structural reinforcement is provided around the shaft hole (4).

The impeller 1 as described above may be divided into a lower portion 10 including the blade 2 and an upper portion 20 positioned above the impeller 1. This is because the casting mold of the impeller 1 generally includes a lower mold (not shown) having a cavity corresponding to the lower portion 10 including the blade 2, and an upper portion 20 of the impeller. This is because the upper mold (not shown) formed with a cavity corresponding to the upper mold.

Since the upper mold corresponds to the impeller upper portion 20 having a simple structure, the fabrication is simple and there are no technical difficulties, while the lower mold must correspond to a plurality of blades 2 having a complicated shape, thickness, and spiral angle. Therefore, a complicated core (not shown) is required.

Figure 2a is a perspective view showing a wooden mold used in the manufacture of a conventional lower mold for casting the impeller, Figure 2b is a perspective view showing the inside of the lower mold molded by the wooden mold of Figure 2a, Figure 2c 2A is a perspective view illustrating a process in which the lower core is disposed inside the lower mold formed by the wooden mold of FIG. 2A.

Conventionally, in order to make the lower mold, first prepare a die 30 as shown in Figure 2a. Using the die 30, the bottom sand 41 is molded into a shape corresponding to the die 30 in the lower frame 40, as shown in Figure 2b.

Then, as shown in FIG. 2C, the lower cores 50, which are provided in a plurality of pieces, are formed on the die 30 to form a cavity corresponding to the blades 2 and the bosses 5 of the impeller 1. It is placed on the top of the molded bottom sand 41.

However, as in the prior art, the process of disposing several pieces of the lower cores 50 is made according to the operator's experience. Therefore, the work productivity is highly dependent on the training of the worker performing the batch work, and a large difference occurs depending on the worker.

In addition, there is a high probability that product defects occur because it depends on the training of the operator, and in particular, there is a limit in that it is difficult to maintain the uniformity of product quality in the shape, thickness and spiral angle of the blade 2.

The present invention has been made to solve the above problems, it is possible to improve the work productivity irrespective of the experience or skill of the operator, and to provide a manufacturing method of the casting mold of the impeller that can ensure the uniformity of the product quality. The purpose is to.

In addition, there is another object to provide an impeller casting mold produced by such a mold manufacturing method and an impeller manufactured by such a mold.

Method for producing a casting mold of the impeller according to an aspect of the present invention, to complete by combining the lower and the upper mold with a cavity (cavity) corresponding to the lower side and the upper side, respectively, wherein the manufacturing of the lower mold Laying a bottom sand in the undercarriage and forming a central lower core having a cavity corresponding to the lower central side of the impeller to be cast; Preparing an outer lower core having a plurality of pieces to form a cavity corresponding to a lower outer side of the impeller, so as to be arranged outside the central lower core; And arranging an outer lower core provided with a plurality of pieces on the outside of the central lower core to complete the lower core.

According to another aspect of the present invention, there is provided a casting mold of the impeller manufactured by the manufacturing method of the casting mold of the impeller.

According to another aspect of the present invention, there is provided an impeller manufactured by a casting mold of the impeller.

The forming of the central lower core may include preparing a wooden die having a corresponding shape to form the central lower core, and forming the central lower core in the bottom sand in the lower mold using the wooden die. It may include.

In addition, a guide surface for guiding the assembly position of the outer lower core is formed at the junction portion of the central lower core to be in contact with the outer lower core, and in the step of completing the lower core, the outer lower portion provided with a plurality of pieces. The lower core may be completed by sequentially arranging the guide surfaces of the central lower core based on the assembly position.

According to the method for manufacturing a casting mold for an impeller according to the present invention, a mold using the same, and an impeller manufactured using the same, an outer shell is formed by using a guide surface of a central lower core provided at a joint after forming a central lower core by a wooden mold. Since the lower cores can be arranged sequentially, the workability for the production of the mold can be improved, thereby improving productivity, as well as obtaining a casting of the impeller with a uniform and stable quality.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Figure 3 is a flow chart showing a manufacturing method of the lower mold in the production of the casting mold of the impeller according to an embodiment of the present invention, Figure 4 is a perspective view showing the wooden mold shown in Figure 3, Figure 5 by the wooden mold shown in Figure 4 6 is a perspective view illustrating a molded center lower core, and FIG. 6 is a perspective view illustrating a process of disposing an outer bottom core outside the center lower core illustrated in FIG. 5.

In order to manufacture the casting mold of the impeller according to an embodiment of the present invention, the lower and upper molds are formed by combining the lower and upper molds respectively corresponding to the lower side and the upper side of the impeller 1 (see FIG. 1). Here, the mold according to the embodiment of the present invention may be used for casting of various materials, for example, cast steel, cast iron, aluminum, stainless steel material may be used, but this is an example, for all types of sand casting. It should be seen that the material is available.

As shown in FIG. 1, the impeller 1 may be divided into a lower portion 10 including a blade 2 and a boss portion 5 and an upper portion 20 positioned above the impeller 1. This is because the casting mold of the impeller 1 generally includes a lower mold 100 having a cavity corresponding to a lower portion 10 including a blade 2 and an upper portion 20 of the impeller. It is because it consists of an upper mold (not shown) in which the corresponding cavity was formed. In addition, the lower portion 10 of the impeller may be divided into a central side 11 corresponding to the shaft hole 4 and the boss portion 5 and an outer side side 12 corresponding to the blade 2.

On the other hand, since the upper mold corresponds to the impeller upper portion 20 of a simple structure, the production of the mold is simple and there are no technical difficulties, while the lower mold 100 has a plurality of complex shapes, thicknesses and spiral angles. In order to cope with the blade 2 and the like, a lower core 120 or the like having a complicated shape is required. Therefore, hereinafter, the description of the manufacturing method of the upper mold which does not have a large difference from the conventional publicly known technologies will be omitted, and the description will be made mainly on the manufacturing method of the lower mold 100 in which the technical features of the present invention are concentrated.

 In order to manufacture the lower mold 100, first, as shown in Figures 3 to 5 to cover the bottom sand 111, such as molding sand in the lower body (110). In addition, a central lower core 121 having a cavity corresponding to the lower side 10 and the center side 11 of the impeller 1 to be cast is formed (S10).

In order to form the central lower core 121 (S10), first, as illustrated in FIG. 4, a die 130 having a shape corresponding to the central lower core 121 is prepared (S11). Then, the central lower core 121 is formed on the bottom sand 111 in the lower frame 110 by using the die 130 (S12).

The central lower core 121 corresponds to the boss portion 5 of the impeller 1 and a portion connecting the boss portion 5 and the blade 2 to each other. Here, a guide surface 123 as a reference for assembly may be formed on the joint surface of the central lower core 121 to be in contact with the outer lower core 122 to be described later to guide the assembly position of the outer lower core 122.

After forming the central lower core 121 (S10), the outer lower core 122 forming a cavity corresponding to the outer side 12 of the lower 10 of the impeller 10 is prepared (S20). Here, the outer lower core 122 is provided in a plurality of pieces to be arranged on the outside of the central lower core 121, respectively.

Next, the lower core 120 is completed by placing the outer lower core 122 provided with a plurality of pieces on the outside of the central lower core 121 (S30). At this time, the outer lower core 122 having a plurality of pieces are arranged in sequence so that the bonding portion is located on the guide surface 123 of the central lower core 121 which is a reference of the assembly position, thereby easily placing the lower core 120. I can complete it.

Finally, the subsequent joining process of the upper and lower cores, the joining process of the upper and lower molds, the process of injecting and casting the molten metal, etc. are well known techniques, and detailed descriptions thereof will be omitted here.

As described above, according to the manufacturing method of the impeller casting mold according to the embodiment of the present invention, when the outer lower core 122 is disposed, it is sequentially along the guide surface 123 of the central lower core 121 as a reference for assembly. Since the workability for the production of the mold, in particular, the work productivity of the lower core 120 may be improved.

In addition, according to the impeller casting mold manufactured by the above manufacturing method of the mold, the casting of which the quality uniformity of the product is ensured because the variation of the shape, spiral angle and thickness of the impeller blade 2 can be kept constant and uniform. Can be secured.

Although the present invention has been described with reference to the embodiments shown in the drawings, this is merely exemplary, and it will be understood by those skilled in the art that various modifications and equivalent other embodiments are possible. Therefore, the true technical protection scope of the present invention will be defined by the technical spirit of the appended claims.

1 is a perspective view showing an example of a casting for an impeller;

Figure 2a is a perspective view showing a wooden mold used in the manufacture of a conventional lower mold for casting the impeller,

Figure 2b is a perspective view showing the inside of the lower mold formed by the die shown in Figure 2a,

FIG. 2C is a perspective view illustrating a process in which the lower core is disposed inside the lower mold formed by the wooden mold illustrated in FIG. 2A;

3 is a flow chart showing a manufacturing method of the lower mold in the manufacture of the casting mold of the impeller according to an embodiment of the present invention,

4 is a perspective view showing a wooden die shown in FIG.

5 is a perspective view showing a central lower core molded by the die shown in FIG. 4;

FIG. 6 is a perspective view illustrating a process of disposing an outer lower core outside the central lower core illustrated in FIG. 5.

<Brief description of symbols for the main parts of the drawings>

10 impeller 100 lower mold

110: lower frame 120: lower core

121: center lower core 122: outer lower core

123: guide surface 130: wooden

Claims (5)

Regarding the manufacturing method of the casting mold of the impeller completed by combining the lower and upper molds formed with cavities corresponding to the lower side and the upper side of the impeller 1, the manufacture of the lower mold 100, In order to form the center lower core 121 in which the bottom sand 111 is laid in the lower body 110 and the cavity corresponding to the lower side 10 center side 11 of the impeller 1 to be cast is formed. Preparing a die 130 having a shape (S11), and forming the central lower core 121 in the bottom sand 111 in the lower frame body 110 using the die 130 (S12) Central lower core molding step (S10) comprising a; By forming a cavity corresponding to the outer side 12 of the lower portion 10 of the impeller 10, the outer lower core 122 is provided in a number of pieces to be arranged on the outside of the central lower core 121, respectively. Preparing a step (S20); And Method of manufacturing a casting mold of the impeller comprising the step (S30) to complete the lower core 120 by placing the outer lower core 122 provided in a plurality of pieces on the outside of the central lower core (121). delete The method according to claim 1, At the junction of the central lower core 121 to be in contact with the outer lower core 122, a guide surface 123 is formed to guide the assembly position of the outer lower core 122. In the step of completing the lower core 120 (S30), the outer surface lower core 122 is provided in a plurality of pieces in order to sequentially arrange the guide surface 123 of the central lower core 121 based on the assembly position Method of manufacturing a casting mold of the impeller by completing the lower core 120 by. The casting mold of the impeller manufactured by the manufacturing method of Claim 1 or 3. An impeller manufactured by the casting mold according to claim 4.

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