A lost foam casting process for suspension bearing

Abstract

The application discloses a kind of suspension support lost foam casting processes, comprising: S1, analysis casting part state under shrinkage hole distribution condition;S2, according to shrinkage hole distribution, set up subsidies and riser, all pin shaft hole side is provided with riser, and all pin shaft hole downside is increased subsidy;S3, hollow resin sand ball is set in neutral position;S4, according to the principle of lost foam mold carbon increase, selects horizontal filling mode, establishes pouring system model.The application is by all pin shaft hole side setting riser, and all pin shaft hole downside is increased subsidy, solve the shrinkage hole problem caused by hot section dispersion;By setting hollow resin sand ball in neutral position, solve the crack problem that joint rib is easy to produce;By using horizontal filling mode, cooperate riser, solve the problem that material carbon content increases, exceeds standard control range.

Description

Technical Field

[0001] This invention relates to the field of casting technology for suspension support frame structures, specifically to a lost foam casting process for suspension supports. Background Technology

[0002] Suspension support castings are thin-walled cast steel parts of the frame type (such as...) Figure 1 As shown in the figure, in the prior art, when the suspension support casting adopts the lost foam casting process, shrinkage cavities are easily generated due to heat dispersion, cracks are easily generated due to large wall thickness deviation and many joint ribs, and carbon increase defects are also easily generated (the white mold material is STMMA, which is a copolymer resin. When heated, it decomposes to form carbon black and gas. The carbon black dissolves in the molten steel, which will lead to an increase in the carbon content of the molten steel, and ultimately an increase in the carbides in the matrix structure). This results in uneven hardness of the casting, increased local brittleness, and reduced plasticity, making it prone to fracture under impact load or alternating load. Summary of the Invention

[0003] This invention provides a lost foam casting process for suspension bearings, which can ensure that the casting is free of shrinkage defects and cracks, and that the carbon content is controlled within the standard range.

[0004] To achieve the above objectives, the present invention employs the following technical solution:

[0005] A lost foam casting process for suspension bearings includes:

[0006] S1. Analyze the distribution of shrinkage cavities in the casting parts under their current state.

[0007] S2. According to the distribution of shrinkage cavities, reasonable subsidies and risers are set to avoid shrinkage defects: risers are set on the sides of all pin holes to play the role of feeding and overflow, and subsidies are added on the bottom side of all pin holes.

[0008] S3. Hollow coated sand balls are placed in the gap position to improve the collapsibility of the sand mold: Coated sand is used to make two hemispheres, and then the two hemispheres are bonded together as a whole with an adhesive. When embedding the mold, the sand ball is placed in the middle of the position where the casting shrinks. After the casting is poured, the temperature of the molten steel acts on the resin sand ball through the molding sand. Under its heat, the resin sand ball collapses. The hollow part of the resin sand ball can reduce the compactness of the sand mold and provide collapsibility space, thereby avoiding cracks caused by obstruction when the casting shrinks.

[0009] S4. Based on the principle of carbon enrichment in lost foam casting, select the filling method to eliminate carbon enrichment defects in cast steel parts: adopt a horizontal filling method to avoid carbon concentration, and cooperate with overflow risers to discharge molten steel with high carbon content into the overflow risers to eliminate the possibility of carbon enrichment in the casting body.

[0010] As a preferred option for the above scheme, the riser height is 180mm.

[0011] As a preferred option, the subsidy width is 50mm.

[0012] As a preferred embodiment of the above scheme, the resin sand ball wall thickness is 15mm.

[0013] As a preferred embodiment of the above scheme, the resin sand ball sizes include Φ80 and Φ60.

[0014] As a preferred option, the molten steel is first horizontally directionally filled and then filled upwards, discharging the carbon-containing and impurity-containing molten steel into the overflow riser.

[0015] Due to the above structure, the beneficial effects of the present invention are as follows:

[0016] 1. By setting risers on the sides of all pin holes and adding pads on the underside of all pin holes, the problem of shrinkage caused by thermal dispersion was solved;

[0017] 2. By setting hollow resin sand balls in the gaps, the problem of cracks easily occurring at the joints of the ribs was solved;

[0018] 3. By adopting a horizontal filling method in conjunction with risers, the problem of increased carbon content in the material exceeding the standard control range was solved. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below.

[0020] Figure 1 This is a structural schematic diagram of a suspension support casting;

[0021] Figure 2 This is a schematic diagram of the riser and subsidy distribution structure of the present invention;

[0022] Figure 3 This is a schematic diagram of the overall structure of the present invention;

[0023] Figure 4 This is a cross-sectional structural diagram of the resin sand ball of the present invention;

[0024] Figure 5 CAE filling contour diagram when molten steel is filled to 15%;

[0025] Figure 6 CAE filling contour map when molten steel is filled to 25%;

[0026] Figure 7 CAE filling contour map when molten steel is 70% filled;

[0027] Figure 8 CAE filling contour diagram when molten steel is filled to 85%. Detailed Implementation

[0028] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0029] This embodiment provides a lost foam casting process for suspension bearings, including:

[0030] S1. Analyze the distribution of shrinkage cavities in the casting parts under their current state.

[0031] S2. Based on the distribution of shrinkage cavities, appropriately set up subsidies and risers (e.g. Figure 2 (As shown), to avoid shrinkage defects: riser 1 is provided on the side of all pin holes, with a riser height of 180mm. Riser 1 serves as both a shrinkage compensation and overflow function; a padding 2 is added on the lower side of all pin holes, with a padding width of 50mm.

[0032] S3. Set hollow resin sand balls 3 (e.g., in the gap position) Figure 3 As shown), to improve the collapsibility of the sand mold: the resin sand ball has a wall thickness of 15mm and is made into two hemispheres using coated sand (as shown). Figure 4 (As shown), the two hemispheres are then bonded together with an adhesive. During the embedding process, the resin sand ball is placed in the middle of the shrinkage area of ​​the casting. The resin sand balls come in two sizes: Φ80 and Φ60. After the casting is poured, the temperature of the molten steel acts on the resin sand ball through the molding sand. Under its thermal action, the resin sand ball collapses. The hollow part of the resin sand ball can reduce the compactness of the sand mold and provide clearance, thereby preventing cracks from forming in frame structure castings such as suspension supports due to obstructed solidification and cooling shrinkage.

[0033] S4. Based on the principle of carbon enrichment in lost foam casting, select the filling method to eliminate carbon enrichment defects in cast steel parts: adopt a horizontal filling method to avoid carbon concentration; the molten steel is first horizontally directionally filled and then filled upwards (e.g., ...). Figures 5 to 8 As shown), in conjunction with the overflow riser, molten steel with a high carbon content (containing carbon and impurities) is discharged into the overflow riser to eliminate the possibility of carbon increase in the casting body.

[0034] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A lost foam casting process for suspension bearings, characterized in that, include: S1. Analyze the distribution of shrinkage cavities in the casting parts under their current state. S2. According to the distribution of shrinkage cavities, reasonable subsidies and risers are set to avoid shrinkage defects: risers are set on the sides of all pin holes to play the role of feeding and overflow, and subsidies are added on the bottom side of all pin holes. S3. Hollow coated sand balls are placed in the gap position to improve the collapsibility of the sand mold: Coated sand is used to make two hemispheres, and then the two hemispheres are bonded together as a whole with an adhesive. When embedding the mold, the sand ball is placed in the middle of the position where the casting shrinks. After the casting is poured, the temperature of the molten steel is applied to the resin sand ball through the molding sand. Under its heat, the resin sand ball collapses. The hollow part of the resin sand ball can reduce the compactness of the sand mold and provide collapsibility space, thereby avoiding cracks caused by obstruction when the frame structure casting cools and shrinks. S4. Based on the principle of carbon enrichment in lost foam casting, select the filling method to eliminate carbon enrichment defects in cast steel parts: adopt a horizontal filling method to avoid carbon concentration, and cooperate with overflow risers to discharge molten steel with high carbon content into the overflow risers to eliminate the possibility of carbon enrichment in the casting body. The molten steel is first horizontally and directionally filled, and then filled upwards to discharge the carbon-containing and impurity-containing molten steel into the overflow riser.

2. The lost foam casting process for suspension bearings according to claim 1, characterized in that, The riser height is 180mm.

3. The lost foam casting process for suspension bearings according to claim 1, characterized in that, The subsidy width is 50mm.

4. The lost foam casting process for suspension bearings according to claim 1, characterized in that, The resin sand ball has a wall thickness of 15mm.

5. The lost foam casting process for suspension bearings according to claim 1, characterized in that, Resin sand balls are available in sizes including Φ80 and Φ60.

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