Casting process method for bottom shell of crusher

Abstract

The invention relates to a casting process method for a bottom shell of a crusher, which is characterized in that a casting process is changed, a split assembled casting core is changed into an integral casting core, and a profile-followed iron framework is designed outside an integral casting core box, so that the strength of the integral casting core box is improved; feeding the wall thickness hot spot part of the shaft head of the bottom shell, and arranging a ceramic tube on the upper surface of a lower flange of the casting; the method has the beneficial effects that the operation process of casting molding and finishing procedures is simplified, the manufacturing period is shortened, the casting period is shortened, and the labor productivity is improved, so that the labor intensity of an operator is reduced, the production efficiency is improved, and the production cost is reduced. Micro casting defects such as internal shrinkage porosity of the bottom shell are reduced, size errors caused by lower core cracks are reduced, the sand falling problem is reduced, and the casting quality of the bottom shell is improved.

Description

Technical Field

[0001] The invention relates to the technical field of casting of spare parts for a mine crusher, and in particular to a casting process method for a bottom shell of a crusher. Background Art

[0002] The bottom shell of the crusher is one of the main cast steel spare parts used in mines for crushing ore equipment. It is responsible for crushing ore and materials. Its working environment is harsh and it is not easy to disassemble and repair, so it has high requirements for the quality of castings. Moreover, the entire surface of the casting needs to be inspected by fluorescent magnetic particle inspection, and some parts need to be inspected by UT inspection. Therefore, it has high requirements for the purity of the molten steel, scientific and reasonable process measures, surface roughness must reach Ra50, and wall thickness requires positive tolerance, which makes manufacturing very difficult.

[0003] Since the bottom shell has a large outline, with a maximum outline size of Φ4000mm*2045mm and a complex shape and structure, there are extremely strict requirements for its quality standards, service life, life stability, assembly accuracy, etc. In the production of bottom shell castings, the large-volume shell casting process is immature, the casting quality is unstable, the quality of large-volume castings cannot be guaranteed, and the casting cycle is long. There is even a delay of more than 8 months in the casting and finishing of a single bottom shell, which seriously restricts the production, installation and commissioning of complete sets of crusher equipment, making the manufacturing period of complete sets of crusher shell equipment long and the shell quality cannot be guaranteed. Summary of the invention

[0004] In order to overcome the shortcomings of the prior art, the present invention provides a casting process method for the bottom shell of a crusher. By changing the casting process, the split-assembly casting core is changed into an integral casting core, an iron skeleton is arranged outside the integral casting core box to improve the strength of the integral casting core, spherical segment-shaped hidden risers and side hidden risers are adopted to strengthen the shrinkage compensation of the hot node of the shaft head wall thickness and improve the casting efficiency, and a ceramic tube is arranged on the upper surface of the lower flange of the bottom shell to avoid gas and slag accumulation at the casting bottom and avoid casting defects such as insufficient pouring of the casting, thereby improving the casting quality and shortening the casting time of the casting.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] A casting process method for a bottom shell of a crusher, the casting process method comprising the following contents:

[0007] S1: Design an innovative casting process solution, improve the mold of the partially assembled casting core into a single integral casting core + live skin sample, and set a free-form iron frame on the outside of the integral casting core box;

[0008] S2: According to the structural characteristics of the casting, a blind riser is set on the U-shaped beam part. According to the shaft head structure, it is divided into two hot zone areas, and a blind riser and a side blind riser are set. The top of the blind riser is made into a spherical riser head. At the same time, an external cooling iron is used to rapidly cool the end area to improve the organizational density of the shaft head structure, and a gas elastic core is used in the blind riser and the side blind riser.

[0009] S3: A ceramic tube is set on the upper surface of the lower flange of the casting, and the top is tightly plugged with high-aluminum refractory fiber. The ceramic tube is resistant to high temperatures, collects slag, and assists in exhausting the casting;

[0010] S4: Use MAGMA software to conduct final simulation confirmation to ensure that there are no excessive internal defects in key parts;

[0011] S5: Use the cavity detector to check the debris in the cavity;

[0012] S6: The surface sand used for casting core is chromite sand with a thickness of 15-20mm, and the rest is ester-hardened water glass recycled sand; the casting fillet is cast with external cooling iron and chromite sand for local quenching. During pouring, the pouring temperature superheat is controlled according to the type of casting steel to achieve low cooling and fast pouring;

[0013] S7: After the casting is heat treated, the amount of grinding on the casting surface is reduced during the finishing process to retain the thickness of the dense layer on the casting surface.

[0014] Furthermore, in the step S6, the purity of the molten steel being poured is improved, and in addition to the electric furnace + LF furnace refining, vacuum treatment is added to reduce the gas and inclusions in the molten steel.

[0015] Furthermore, in step S6, the pouring temperature superheat is controlled at 40-50°C.

[0016] Furthermore, the live skin modeling in step S1 is a wedge-shaped protruding wood structure made in sections according to the external structural characteristics of the bottom shell body and matched with the concave structure of the middle wood entity.

[0017] Furthermore, the key parts in step S4 include the inner and outer annular structures at the center of the bottom shell and the shaft head.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] 1. The bottom shell of the crusher is cast by integral casting core molding, which reduces micro casting defects such as internal shrinkage of the bottom shell, reduces the dimensional error caused by the splitting of the lower core, reduces the sand falling problem, improves the casting quality of the bottom shell, extends the service life of the casting, and improves the overall casting level of the export frame casting.

[0020] 2. The combination of spherical riser and blind riser is adopted, and the external chiller is used to strengthen the shrinkage compensation of the hot section of the shaft head wall thickness, improve the organizational density of the shaft head structure, improve the casting efficiency, and improve the casting quality.

[0021] 3. It simplifies the operation process of casting molding and finishing process, shortens the production period of castings and the manufacturing cycle of the whole set of equipment, improves labor productivity, and thus reduces the labor intensity of operators.

[0022] 4. A ceramic tube is set at the lower flange of the bottom shell casting, which has good high temperature resistance, reduces impurities entering the high-temperature molten steel, and improves the cleanliness of the poured high-temperature molten steel. The ceramic tube has good air permeability, which is beneficial to the exhaust of the casting during the casting process, avoids gas and slag accumulation at the bottom of the casting, and causes casting defects such as insufficient pouring, making the large flat surface at the bottom of the casting smoother, improving the quality of the casting and reducing casting defects. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the process of a crusher bottom shell casting (including riser) described in the present invention.

[0024] Figure 2 It is a schematic diagram of a semi-section of the process of the crusher bottom shell casting (including riser + external chiller) described in the present invention.

[0025] Figure 3 It is a schematic diagram of the arrangement of the ceramic tubes described in the present invention.

[0026] Figure 4 This is a diagram of a crusher bottom casing casting according to the present invention.

[0027] Figure 5 It is a schematic diagram of the conventional casting process of the bottom shell of the crusher described in the present invention.

[0028] In the figure: 1. integral casting core; 2. blind riser; 3. side blind riser; 4. lower flange; 5. external chiller; 6. ceramic tube; 7. casting. DETAILED DESCRIPTION

[0029] The specific embodiments of the present invention are further described below:

[0030] In the description of the present invention, it is necessary to understand that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "lateral, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the drawings. They are only for the convenience of describing the present invention and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the device or element referred to must have a specific direction or be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the scope of protection of the present invention: the directional words "inside and outside" refer to the inside and outside relative to the contours of each component itself.

[0031] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used herein to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below their position devices or structures". Thus, the exemplary term "above" may include both "above" and "below". The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly. If not otherwise stated, the above words have no special meaning and therefore cannot be understood as limiting the scope of protection of the present invention.

[0032] like Figure 1-Figure 5 As shown, a casting process method for the bottom shell of a crusher, the casting process method includes the following contents:

[0033] S1: Design an innovative casting process solution, improve the mold of the partially assembled casting core into a single integral casting core 1 + live skin solid sample, set a mold-free iron frame on the outside of the integral casting core box to improve the strength of the integral casting core, thereby reducing the equal division of the sand core, reducing the dimensional error and sand loss caused by the split seam of the lower core, thereby ensuring the cleanliness of the cavity and improving the intrinsic quality of the casting;

[0034] S2: According to the structural characteristics of the casting, two blind risers 2 are respectively provided in the two U-shaped beam parts, and the top of the blind riser 2 is made into a spherical riser head; in addition to the blind riser 2 of the U-shaped beam part, according to the shaft head structure, the shaft head is divided into two hot zone areas, and a blind riser 2 and a side blind riser 3 are respectively provided. At the same time, an external cooling iron is used to rapidly cool the end area to improve the organizational density of the shaft head structure, and an air elastic core is used in the blind riser 2 and the side blind riser 3 to improve the shrinkage compensation efficiency of the blind riser 2 and the side blind riser 3, focusing on ensuring the shrinkage compensation of the hot zone of the shaft head wall thickness, and at the same time, an external cooling iron 5 is used to rapidly cool the end area of ​​the casting, thereby improving the organizational density of the shaft head structure, and further improving the shrinkage compensation effect of the riser and the casting process yield;

[0035] S3: A ceramic tube is arranged on the upper surface of the lower flange 4. A total of 16 Φ3x200 ceramic tubes 6 are arranged on the upper surface of the lower flange 4 of the casting 7. Four ceramic tubes 6 are arranged on each side of the square flange. The ceramic tube 6 is placed on the flange sample during molding. The top is tightly plugged with high-aluminum refractory fiber to prevent sand from falling into the ceramic tube 6. The ceramic tube 6 is resistant to high temperatures and plays a role in assisting casting exhaust. After the high-temperature molten steel is poured in, it encounters the bottom ceramic tube 6. The high-temperature resistance of the ceramic tube 6 is not easily eroded and corroded by the high-temperature molten steel, ensuring the cleanliness of the molten steel. In addition, the ceramic tube 6 is placed at the lower flange 4 of the pouring system for good exhaust effect, avoiding gas and slag accumulation at the bottom of the casting, avoiding insufficient pouring, and making the large plane at the bottom of the casting 7 smoother.

[0036] S4: Use MAGMA software for final simulation confirmation to ensure that there are no excessive internal defects in key parts. Use computer-aided means to simulate the pouring situation and predict the pouring quality of key parts in advance. If there are excessive internal defects, the casting process can be improved before pouring to deal with them in time and improve the pouring quality;

[0037] S5: Use the cavity detector to check whether there is sand or other debris in the cavity that affects the casting quality, so as to improve the casting quality;

[0038] S6: The surface sand used for casting core is chromite sand with a thickness of 15-20mm, and the rest is recycled sand with a thickness of more than 200mm; the casting fillet uses external cooling iron 5 and local chromite sand for local quenching to prevent casting defects such as shrinkage and shrinkage holes. During pouring, the pouring temperature superheat is controlled according to the type of casting steel to achieve low cooling and fast pouring, and the riser is supplemented strictly according to the pouring process to improve the shrinkage supplement efficiency of the riser;

[0039] S7: During the subsequent cleaning and polishing process of the casting, the amount of surface polishing is reduced, the thickness of the dense layer on the surface of the casting is retained, and the mechanical properties and service life of the casting are improved.

[0040] Furthermore, in the step S6, the purity of the molten steel being poured is improved, and in addition to the electric furnace + LF furnace refining, vacuum treatment is added to reduce the gas and inclusions in the molten steel.

[0041] Furthermore, in step S6, the pouring temperature superheat is controlled at 40-50°C.

[0042] Furthermore, the live skin sample modeling in step S1 is a wedge-shaped protruding wood structure produced in sections according to the external structural characteristics of the bottom shell, which is matched with the solid concave structure of the middle wood mold, which is convenient for demoulding and on-site operation, and ensures that the sand mold is not damaged.

[0043] Furthermore, the key parts in step S4 include the inner and outer annular structures at the center of the bottom shell and the shaft head.

[0044] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical solutions and concepts of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A casting process for a crusher bottom shell, characterized in that: The casting process comprises the following contents: S1: Design an innovative casting process solution, improve the mold of the partially assembled casting core into a single integral casting core + live skin sample, and set a free-form iron frame on the outside of the integral casting core box; S2: According to the structural characteristics of the casting, a blind riser is set on the U-shaped beam part. According to the shaft head structure, it is divided into two hot zone areas, and a blind riser and a side blind riser are set. The top of the blind riser is made into a spherical riser head. At the same time, an external cooling iron is used to rapidly cool the end area to improve the organizational density of the shaft head structure, and a gas elastic core is used in the blind riser and the side blind riser. S3: A ceramic tube is set on the upper surface of the lower flange of the casting, and the top is tightly plugged with high-aluminum refractory fiber. The ceramic tube is resistant to high temperatures, collects slag, and assists in exhausting the casting; S4: Use MAGMA software to conduct final simulation confirmation to ensure that there are no excessive internal defects in key parts; S5: Use the cavity detector to check the debris in the cavity; S6: The surface sand used for casting core is chromite sand with a thickness of 15-20mm, and the rest is ester-hardened water glass recycled sand; the casting fillet is cast with external cooling iron and chromite sand for local quenching. During pouring, the pouring temperature superheat is controlled according to the type of casting steel to achieve low cooling and fast pouring; S7: After the casting is heat treated, the amount of grinding on the casting surface is reduced during the finishing process to retain the thickness of the dense layer on the casting surface.

2. The casting process of the bottom shell of a crusher according to claim 1 is characterized in that: In the step S6, the purity of the molten steel being poured is improved, and in addition to the electric furnace + LF furnace refining, vacuum treatment is added to reduce the gas and inclusions in the molten steel.

3. The casting process of the bottom shell of a crusher according to claim 1 is characterized in that: In step S6, the pouring temperature superheat is controlled at 40-50°C.

4. The casting process of the bottom shell of a crusher according to claim 1 is characterized in that: The live skin modeling in step S1 is a wedge-shaped protruding wood structure made in sections according to the external structural characteristics of the bottom shell body and matched with the concave structure of the middle wood entity.

5. The casting process of the bottom shell of a crusher according to claim 1 is characterized in that: The key parts in step S4 include the inner and outer annular structures at the center of the bottom shell and the shaft head.

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