Casting method of volute steel casting

Abstract

The invention belongs to the technical field of casting, and mainly relates to a casting method of a volute steel casting with a narrow runner, which comprises the following steps: dividing a volute steel casting sand core into a main body sand core and an inner cavity sand core, and assembling the main body sand core and the inner cavity sand core to form a volute cavity; the inner cavity sand core is divided into a first sand core body and a second sand core body, the first sand core body is manufactured in a 3D printing mode, and the second sand core body is manually manufactured through chromium ore; the first sand core is divided into a first printing sand core and a second printing sand core; by adopting the casting method provided by the invention, the automation level and the production efficiency of steel casting production are improved.

Description

Technical Field

[0001] The invention belongs to the technical field of casting, and mainly relates to a casting method of a volute steel casting with a narrow flow channel. Background Art

[0002] As an indispensable component in industrial production, volute casting is a core component, especially in the field of liquid transportation. Since the volute is used under high temperature and high pressure, and has a complex structure, the wall thickness of some parts varies greatly, the flow channel is extremely narrow, and the finished casting is required to be leak-proof and polished as a whole, the casting is extremely difficult; during the casting process, the pouring temperature of this type of casting is too high, especially in the flow channel, where heat is easily concentrated, which is very easy to produce sand sticking defects, and the sand core in the flow channel is prone to breakage risks. How to overcome these problems in the casting process needs to be solved urgently. Summary of the invention

[0003] Based on the above problems, it is necessary to propose a casting method for a volute steel casting to produce a volute steel casting that meets the requirements.

[0004] A casting method for a volute steel casting, the casting method comprising the following steps: dividing the sand core of the volute steel casting into a main sand core and an inner cavity sand core, the main sand core and the inner cavity sand core are assembled to form a volute cavity; dividing the inner cavity sand core into a first sand core and a second sand core, the first sand core is made by 3D printing, and the second sand core is made by hand by chromium ore sand; dividing the first sand core into a printed sand core 1 and a printed sand core 2.

[0005] In one embodiment, the main sand core is made of 3D printed silica sand to improve the accuracy and strength of the sand core.

[0006] In one embodiment, the first sand core is made of silica sand to ensure the accuracy of its complex structure.

[0007] In one embodiment, the casting method further comprises making a core bone, and arranging the mold-free core bone inside the inner cavity sand core to enhance the structural stability of the inner cavity sand core.

[0008] In one embodiment, the warping angle of each core bar of the mold-free core bar is set to 5° to 10° to meet the deformation requirements during the casting process.

[0009] In one embodiment, the casting method further includes making a core box, and the core box is used to make the second sand core; dividing the core box into a main core box, a first movable block core box, a second movable block core box, a third movable block core box, and a fourth movable block core box; placing the core bone at a set position in the main core box, and assembling the first movable block core box, the second movable block core box, the third movable block core box, and the fourth movable block core box respectively, and filling sand in sections and compacting them to form the second sand core.

[0010] In one embodiment, a core assembly reserved hole is provided on the second sand core, and the core assembly reserved hole is used to place a connecting piece; the core assembly reserved hole is matched with the connecting piece to ensure a stable connection between the second sand core and the second printing sand core.

[0011] In one embodiment, a plurality of sand filling grooves are provided on the printing sand core, and sand is filled in the sand filling grooves to prevent core floating.

[0012] In one embodiment, the depth of the sand filling groove is 80 mm to 150 mm to ensure sufficient filling volume and strength.

[0013] In one embodiment, the draft angle of the sand filling groove is 3° to 8° to facilitate filling with resin sand.

[0014] In one embodiment, the sand filling groove is configured to be circular or square to meet different casting requirements.

[0015] In one embodiment, a core cap positioning point is provided at the topmost end surface of the printed sand core to prevent the inner cavity sand core from moving, thereby ensuring accurate positioning and stable connection of the sand core during the casting process.

[0016] In one embodiment, the casting method further includes a core assembly step, first placing the main sand core on the bottom plate, placing the printed sand core 1, and accurately positioning it with the main sand core; then placing the second sand core, and then assembling the printed sand core 2; subsequently placing the connecting piece, so that the second sand core and the printed sand core 2 are assembled as a whole, to prevent stress during the pouring process, resulting in floating core phenomenon. Finally, resin sand is filled in several of the sand filling grooves, and compacted, so that the second sand core and the printed sand core 1 become a whole, mainly using the draft angle and mutual inlaying to avoid the floating core phenomenon.

[0017] The casting method of the volute steel casting provided by the present invention has the following beneficial effects:

[0018] (1) The present invention adopts a coreless fixing method, and realizes stable fixing of the sand core during the casting process by optimizing the structural design of the sand core and the casting process. This method not only simplifies the casting process, but also improves the precision and quality of the casting, brings higher efficiency and more reliable performance to the production of volute steel castings, and overcomes the problem that positioning and supporting with the help of core heads may increase the complexity and cost of casting.

[0019] (2) The core box design in the present invention adopts a combination of a main core box and a movable core box. This method not only simplifies the production process of the core box and reduces costs, but also improves the flexibility and adaptability of the core box. By adjusting the position and combination of the movable core box, sand cores of various shapes and sizes can be easily produced to meet the diverse casting needs of volute steel castings. In addition, this core box design also facilitates the assembly and disassembly of the sand core, improving the automation level and production efficiency of casting production.

[0020] (3) The present invention adopts a method of combining 3D sand cores with manual core production. 3D sand core printing technology has the characteristics of high precision and complex structure; while manual cores are completed through traditional manual production methods, which have the advantages of flexibility and cost-effectiveness. The combination of the two can give full play to their respective advantages and achieve stable and reliable connections between sand cores. This connection method not only improves the precision and quality of castings, but also reduces production costs and cycles, bringing greater flexibility and competitiveness to the production of volute steel castings. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Attached Figure 1 It is an overall schematic diagram of the sand core assembly of the embodiment;

[0022] Attached Figure 2 Schematic diagram of the inner cavity sand core structure of the embodiment;

[0023] Attached Figure 3 This is a schematic diagram of the second sand core structure of the embodiment;

[0024] Attached Figure 4 Schematic diagram of the core box structure of the embodiment;

[0025] Attached Figure 5 This is a schematic diagram of the structure of a printed sand core in an embodiment;

[0026] Attached Figure 6 for Figure 5 AA section view;

[0027] 10-main body sand core; 20-inner cavity sand core; 21-first sand core; 22-second sand core; 211-printing sand core one; 212-printing sand core two; 2111-filling sand groove; 221-core assembly reserved hole; 30-core bone; 40-core box; 41-main body core box; 42-first movable core box; 43-second movable core box; 44-third movable core box; 45-fourth movable core box; 50-connecting piece. DETAILED DESCRIPTION

[0028] In order to facilitate the understanding of the present invention, the present invention will be described more fully below, and preferred embodiments of the present invention are provided. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present invention more thoroughly and comprehensively understood.

[0029] This embodiment mainly relates to a volute steel casting with an extremely narrow flow channel structure, and provides a casting method for the volute steel casting. Figures 1 to 6 As shown, the specific steps include:

[0030] Step 1: Sand core division design and production. The sand core division principle is determined according to the molding process, quality requirements and processing technology of the steel casting. It is necessary to design the inner cavity sand core 20 separately, and divide the steel casting sand core into the main sand core 10 and the inner cavity sand core 20. The main sand core 10 and the inner cavity sand core 20 are assembled to form a volute cavity. Among them, the main sand core 10 is made of 3D printed silica sand.

[0031] Step 2: The inner cavity sand core 20 is divided, designed and manufactured. The inner cavity sand core 20 is divided into a first sand core 21 and a second sand core 22. The first sand core 21 is made by 3D printing, and the second sand core 22 is made by hand using chrome ore sand; the first sand core 21 is divided into a printed sand core 1 211 and a printed sand core 212. The first sand core 21 is also made of silica sand.

[0032] Specifically, in order to prevent the core from drifting, a plurality of sand filling grooves 2111 are provided on the printed sand core 1 211, and sand is filled in the sand filling grooves 2111. The sand filling grooves 2111 are set to be circular or square, with a depth of 80 mm to 150 mm and a draft angle of 3° to 8°. At the same time, in order to ensure accurate positioning and stable connection of the sand core during the casting process, a core cap positioning point is set at the top end surface of the printed sand core 1 211.

[0033] Step 3: Making the core bone 30. In order to prevent the flow channel of the volute casting from collapsing and to better support the flow channel structure, a mold-free core bone 30 is set inside the inner sand core 20. According to the specific shape and direction of the flow channel, the contour of the core bone 30 is customized to make it fit closely with the flow channel to achieve effective support.

[0034] Specifically, in order to further enhance the support stability of the core bone 30, a precise angle warping design of 5° to 10° is implemented for each core bone 30 within the tilt range of 0° to 30°. This can disperse stress concentration points, improve the ability of the core bone 30 to resist deformation, and maintain the integrity of the structure even when subjected to a large load. At the same time, the angle warping also helps to increase the contact area between the core bone 30 and the surrounding structure, thereby improving the overall connection strength.

[0035] Step 4: Use the core box 40 to make the second sand core 22. The core box 40 is used to make the second sand core 22; divide the core box 40 into a main core box 41, a first movable core box 42, a second movable core box 43, a third movable core box 44, and a fourth movable core box 45; place the core bone 30 at a set position in the main core box 41, assemble the first movable core box 42, the second movable core box 43, the third movable core box 44, and the fourth movable core box 45 respectively, and fill the sand in sections at the same time, pay attention to filling the sand from the narrowest part, to form the second sand core 22.

[0036] Specifically, a core assembly reserved hole 221 is provided on the second sand core 22 , and the core assembly reserved hole 221 is used to place the connecting piece 50 ; the core assembly reserved hole 221 is matched with the connecting piece 50 to ensure a stable connection between the second sand core 22 and the second printing sand core 212 .

[0037] Step 5: Core assembly. First, place the main sand core 10 on the bottom plate, and then place the printed sand core 1 211, accurately positioning it with the main sand core 10; then place the second sand core 22, and then assemble the printed sand core 2 212; then place the connector 50, so that the second sand core 22 and the printed sand core 2 212 are assembled as a whole to prevent stress during the pouring process and cause core floating. Finally, fill the resin sand in several sand filling grooves 2111 and tighten it, so that the second sand core 22 and the printed sand core 1 211 become a whole, mainly using the draft angle and mutual inlaying to avoid the floating core phenomenon.

[0038] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0039] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A casting method for a spiral casing steel casting, characterized in that: The casting method comprises the following steps: dividing the sand core of the volute steel casting into a main sand core and an inner cavity sand core, wherein the main sand core and the inner cavity sand core are assembled to form a volute cavity; dividing the inner cavity sand core into a first sand core and a second sand core, wherein the first sand core is made by 3D printing, and the second sand core is made by hand by using chromium ore sand; and dividing the first sand core into a printed sand core one and a printed sand core two.

2. The casting method of the spiral casing steel casting according to claim 1, characterized in that: The main sand core is made of 3D printed silica sand.

3. The casting method of spiral casing steel casting according to claim 1, characterized in that: The first sand core is made of silica sand.

4. The casting method of spiral casing steel casting according to claim 1, characterized in that: The casting method also includes making a core bone, and arranging the mold-free core bone inside the inner cavity sand core.

5. The casting method of spiral casing steel casting according to claim 4, characterized in that: The warping angle of each core bar of the mold-free core bar is set to 5° to 10°.

6. The casting method of spiral casing steel casting according to claim 5, characterized in that: The casting method also includes core box making, the core box is used to make the second sand core; dividing the core box into a main core box, a first movable block core box, a second movable block core box, a third movable block core box, and a fourth movable block core box; placing the core bone at a set position in the main core box, assembling the first movable block core box, the second movable block core box, the third movable block core box, and the fourth movable block core box respectively, and filling sand in sections and compacting them at the same time to form the second sand core.

7. The casting method of spiral casing steel casting according to claim 6, characterized in that: The second sand core is provided with a core assembly reserved hole, the core assembly reserved hole is used to place a connecting piece, and the core assembly reserved hole is matched with the connecting piece.

8. The casting method of spiral casing steel casting according to claim 1, characterized in that: A plurality of sand filling grooves are arranged on the printing sand core.

9. The casting method of spiral casing steel casting according to claim 1, characterized in that: The depth of the sand filling groove is 80 mm to 150 mm.

10. The casting method of spiral casing steel casting according to claim 1, characterized in that: The draft angle of the sand filling groove is 3° to 8°.

Images