Integrated ceramic core for investment casting of regulating valve body

Abstract

The utility model discloses an integrated ceramic core for investment casting of a valve body of a regulating valve, which comprises a ceramic core body, a grouting port is arranged on the ceramic core body, a phenolic resin ceramic sand core is embedded on the ceramic core body, and the phenolic resin ceramic sand core corresponds to a narrow corner of an inner cavity of a wax mould. The ceramic core body is provided with the phenolic resin ceramic sand core, the phenolic resin ceramic sand core corresponds to the narrow corner of the inner cavity of the wax mold, and in addition, the cleaning hole is formed in the integrated ceramic core, so that internal slurry dipping and sand coating are facilitated, and floating sand and bridging problems are solved. By means of the design, the artillery fire rate can be reduced to 0-7% in the pouring process of the integrated ceramic core.

Description

Technical Field

[0001] The utility model particularly relates to an integral ceramic core for investment casting of a control valve body. Background Art

[0002] Most core-making in foundries adopts the perfusion method. That is, after the wax pattern is made into a mold shell, areas with insufficient internal cavity strength are filled and reinforced with slurry and sand, dried in a constant temperature and humidity workshop to remove moisture, and heated under high temperature and high pressure to make the wax liquid flow out to obtain a conventional core (i.e., the shell mold formed by slurry and sand). Metal solution is injected into the shell mold. After cooling, the shell mold is removed to obtain the casting. For casting some castings, such as the control valve body, the required shell mold structure is relatively complex. Then, the inner cavity of the wax pattern adapted to the shape of the shell mold has narrow corners. When using the direct perfusion method, the stability and rigidity are poor, and due to the narrow corner structure, "voids" are likely to appear during perfusion, even blocking the perfusion process (generally caused by the problems of "floating sand" or "bridging"). The ceramic core obtained after dewaxing is "strong on the outside and dry on the inside", so the ceramic core shows a gunfire phenomenon during pouring, forming defective products. Content of the Utility Model

[0003] The utility model aims to solve at least one of the technical problems existing in the prior art. For this reason, the utility model provides an integral ceramic core for investment casting of a control valve body.

[0004] To solve the above existing technical problems, the utility model adopts the following technical solutions:

[0005] An integral ceramic core for investment casting of a control valve body includes a ceramic core body. A grouting port is arranged on the ceramic core body. A phenolic resin ceramic sand core is embedded on the ceramic core body, and the phenolic resin ceramic sand core corresponds to the narrow corners of the inner cavity of the wax pattern.

[0006] Preferably, the number of the phenolic resin ceramic sand cores is 2.

[0007] Preferably, the phenolic resin ceramic sand core includes a sand core main body and connecting parts arranged on both sides of the sand core main body.

[0008] Preferably, a cleaning hole is arranged on the ceramic core body, and the cleaning hole is filled with surface layer slurry.

[0009] The beneficial effects of the utility model are:

[0010] The integrated ceramic core of the present application includes a ceramic core body, on which a grouting port is provided. A phenolic resin ceramic sand core is inlaid on the ceramic core body, and the phenolic resin ceramic sand core corresponds to the narrow corner of the inner cavity of the wax mold. In addition, a cleaning hole is provided on the integrated ceramic core to facilitate the cleaning of the internal slurry adhering and sanding, as well as the problems of floating sand and bridging. With this design, the defective rate of the integrated ceramic core can be reduced to 0-7% during casting. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The above and / or additional aspects and advantages of the present utility model will become apparent and be readily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0012] Figure 1 Schematic diagram of the wax mold structure for fabricating the integrated ceramic core of the present application Figure 1 ;

[0013] Figure 2 Schematic diagram of the wax mold structure for fabricating the integrated ceramic core of the present application Figure 2 ;

[0014] Figure 3 Schematic diagram of the wax mold structure for fabricating the integrated ceramic core of the present application Figure 3 ;

[0015] Figure 4 Schematic diagram of the structure of the integrated ceramic core of the present application Figure 1 ;

[0016] Figure 5 Schematic diagram of the structure of the integrated ceramic core of the present application Figure 2 . DETAILED DESCRIPTION OF THE EMBODIMENTS

[0017] The embodiments of the present utility model will be described in detail below. The embodiments are illustrated in the accompanying drawings, where the same or similar reference numerals denote the same or similar elements or elements with the same or similar functions throughout.

[0018] The orientation shown in the drawings should not be construed as limiting the specific protection scope of the present utility model. It is only for reference and understanding of the preferred embodiments. The positions of the product components shown in the drawings can be changed, the quantity can be increased, or the structure can be simplified.

[0019] The "connection" described in the specification and the "connection" relationship between the components shown in the drawings can be understood as fixedly connected, detachably connected, or integrally formed; it can be directly connected or connected through an intermediate medium. Those of ordinary skill in the art can understand the connection relationship according to the specific situation and can obtain different implementation manners such as screwing, riveting, welding, clamping, or embedding for substitution in a suitable manner.

[0020] The directional terms such as upper, lower, left, right, top, bottom, etc. described in the specification and the directions shown in the drawings. Each component can be in direct contact or contact through other features between them; for example, "above" can be directly above or obliquely above, or it only means higher than other objects; the same can be analogously understood for other directions.

[0021] The manufacturing materials of the components with solid shapes shown in the specification and the drawings can be metal materials, non-metal materials or other composite materials; the machining processes applicable to the components with solid shapes can be stamping, forging, casting, wire cutting, laser cutting, injection molding, numerical milling, 3D printing, machining, etc.; those of ordinary skill in the art can adaptively select or select in combination according to different processing conditions, costs, and precisions, but are not limited to the above materials and manufacturing processes.

[0022] An integrated ceramic core for investment casting of a control valve body, comprising a ceramic core body 4. A grouting port 6 is arranged on the ceramic core body 4. A phenolic resin ceramic sand core 2 is embedded on the ceramic core body 4, and the phenolic resin ceramic sand core 2 corresponds to the narrow corner of the inner cavity 5 of the wax mold 1.

[0023] Further, the number of the phenolic resin ceramic sand cores 2 is two.

[0024] Further, the phenolic resin ceramic sand core 2 includes a sand core main body 21 and connecting parts 22 arranged on both sides of the sand core main body 21.

[0025] Further, a cleaning hole 7 is arranged on the ceramic core body 4, and a surface layer slurry 8 is filled in the cleaning hole 7.

[0026] The working principle of the present utility model is:

[0027] As Example 1, taking the integrated ceramic core in Figures 4 - 5 as an example, Figures 1 - 3 the wax mold 1 used in this application, as Figures 2 - 3As shown in the figure, a phenolic resin ceramic sand core 2 is inlaid at the narrow corner of the inner cavity 5 of the wax mold 1; two facing layers are applied to the wax mold 1, and then it is placed in a constant temperature and humidity drying room for 6-10 hours. Then, two layers of 30 / 60# sand and two layers of 16 / 30# sand are applied, and it is placed in a constant temperature and humidity drying room for 8-12 hours. After removing the wax mold 1, a prefabricated core mold is obtained. In the above technical solution, during the production of the prefabricated core mold, a drilling hole 10 can be drilled on the wax mold 1 with a drill bit. After dewaxing, a cleaning hole 7 corresponding to the drilling hole 10 will appear on the surface of the corresponding prefabricated core mold. This cleaning hole 7 facilitates the application of slurry and sand to the inside of the prefabricated core mold and the cleaning of floating sand. The prefabricated core mold is baked to remove residual wax and moisture. After cooling, the cleaning hole 7 is taped with adhesive tape, and the ceramic sand core material with the patent number 202410496228.8 is poured into the prefabricated core mold. After pouring, it is placed in a constant temperature and humidity drying room for 72 hours. Then, the position of the cleaning hole 7 is polished and repaired with a facing slurry 8 and 800-mesh sandpaper, and finally an integrally formed ceramic core with a qualified surface is obtained.

[0028] It can be seen from Figure 4 that the integrally formed ceramic core formed is inlaid with a phenolic resin ceramic sand core 2. The corresponding position of the phenolic resin ceramic sand core 2 is the narrow corner of the inner cavity 5 of the wax mold 1. The narrow corner is the position where the problems of "floating sand" or "bridging" are likely to occur in this technical field, generally the narrowest position in the inner cavity 5. And the integrally formed ceramic core of the present application has a phenolic resin ceramic sand core 2. The phenolic resin ceramic sand core 2 has high strength, a relatively large gas evolution amount and a long gas evolution time. However, due to its small size, the gas evolution problem can be solved by short-time baking. Taking the casting of a regulating valve body as an example, the metal solution is injected into the slurry injection port 6 of the integrally formed ceramic core. The shape of the integrally formed ceramic core corresponds to that of the regulating valve body. After cooling, the integrally formed ceramic core is removed to obtain the regulating valve body.

[0029] Regarding the structure of the phenolic resin ceramic sand core 2, reference can be made to Figure 5 , which includes a sand core main body 21 and connecting parts 22 arranged on both sides of the sand core main body 21.

[0030] Next, the integrally formed ceramic core designed in the present application and the conventional core making are used for test comparison. The regulating valve body is cast and made by using the integrally formed ceramic core and the conventional core making respectively, and the shelling rate is counted.

[0031] Product Number of production pieces Qualified products Fire ratio Conventional core making 15 5 67％ Conventional core making 10 3 70％ Conventional core making 8 2 75％ Integrated ceramic core of the present application 16 16 0 Integrated ceramic core of the present application 22 22 0 Integrated ceramic core of the present application 14 13 7％

[0032] It can be seen from the above experimental data that when using the integrally formed ceramic core of the present application to cast the regulating valve body, the shelling ratio during pouring is 0-7%, while the shelling ratio of the regulating valve body cast by the conventional core making is as high as 67-75%. That is to say, the integrally formed ceramic core of the present application reduces the shelling rate during pouring, thereby reducing the product rejection rate.

[0033] Although the present utility model has been described in detail with reference to the above embodiments, it will be apparent to those skilled in the art from this disclosure that various changes or modifications can be made to the present utility model without departing from the principle and spirit scope defined by the claims. Therefore, the detailed description of the embodiments of this disclosure is only for explanation and not for limiting the present utility model, but the scope of protection is defined by the content of the claims.

Claims

1. An integral ceramic core for investment casting of a regulating valve body, characterized in that, It includes a ceramic core body (4), a grouting port (6) is arranged on the ceramic core body (4), a phenolic resin ceramic sand core (2) is embedded on the ceramic core body (4), and the phenolic resin ceramic sand core (2) corresponds to the narrow corner of the inner cavity (5) of the wax mold (1).

2. The integrated ceramic core for investment casting of a regulating valve body according to claim 1, wherein, The number of the phenolic resin ceramic sand cores (2) is two.

3. An integrated ceramic core for investment casting of a regulating valve body according to claim 1, characterized in that, The phenolic resin ceramic sand core (2) includes a sand core main body (21) and connecting parts (22) arranged on both sides of the sand core main body (21).

4. An integrated ceramic core for investment casting of a regulating valve body according to claim 1, characterized in that, A cleaning hole (7) is arranged on the ceramic core body (4), and a surface layer slurry (8) is filled in the cleaning hole (7).

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