Point-to-point feeding gating system and method for heavy section casting with lifting lugs
By using a point-to-point feeding gating system with a single main runner and four ingates, the cross-sectional area ratio and transition fillets are optimized, solving the problems of complex gating systems and low process yield for castings with thick lifting lugs, and achieving efficient casting production.
Patent Information
- Application Number
- CN202610531923.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-04-21
- Publication Date
- 2026-06-30
AI Technical Summary
In the existing technology, the casting process of castings with thick lifting lugs has problems such as complex gating systems, low process yield, high production costs and low production efficiency. In particular, the need for multiple ingates at the lifting lug position of the casting results in a large amount of material used in the gating system and a large amount of cleaning work.
A point-to-point feeding gating system is adopted, including a single main gating channel and four ingates. The cross-sectional area ratio is optimized, and transition fillets and locally thickened sections are set at the connection between the ingates and the lifting lugs. Precise feeding of molten metal is achieved through a single feeding channel, simplifying the gating system structure.
Significantly improves process yield to over 85%, reduces runner material usage by 50%, simplifies casting cleaning process, reduces production costs, and improves production efficiency.
Smart Images
Figure CN122298925A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of lost-mold casting technology, and in particular to a point-to-point feeding gating system and method for casting thick parts of lifting lugs in lost-mold casting. Background Technology
[0002] Lost foam casting (also known as foam casting) is a casting method in which foam models similar in size and shape to the casting are bonded together to form a model cluster, coated with refractory paint and dried, buried in dry quartz sand and vibrated to form a shape, and then poured under negative pressure, causing the model to vaporize, the liquid metal to occupy the model position, and the casting to be formed after solidification and cooling.
[0003] In actual production, some castings have lifting lug structures, and the lifting lug areas are usually quite thick, forming localized hot spots in the casting. In existing processes, to ensure sufficient feeding in these thick areas and avoid shrinkage cavities and porosity defects, multiple ingates are typically placed near these areas to maintain continuous molten iron filling and feeding. However, this arrangement of multiple ingates results in a large amount of material used in the gating system and a complex runner structure, increasing production costs and leading to a significantly low yield; the yield of some castings is only around 70%. For thick structural parts, existing lost foam casting often uses multiple insulating risers for slag removal and feeding, resulting in low yield and significant cost waste. Furthermore, the multiple ingates also increase the workload of casting cleaning, reducing production efficiency.
[0004] Therefore, how to simplify the gating system structure and improve the process yield while ensuring the casting quality of the thick parts of the lifting lugs is a technical problem that urgently needs to be solved in this field. Summary of the Invention
[0005] In view of this, the purpose of this invention is to provide a point-to-point feeding and gating system and method for casting thick parts of lifting lugs in solid casting, which solves the problems in the background art.
[0006] To achieve the above objectives, this invention provides a point-to-point feeding gating system for casting thick sections of lifting lugs in solid casting, comprising a pouring cup, a sprue, and a runner. The pouring cup is connected to the sprue, and the sprue is connected to the runner. The runner is a main runner arranged along the length of the foam model of the casting. Four ingates are provided above the runner, directly connected to the thick sections of the lifting lugs at the four corners of the foam model, forming a single feeding channel from the runner to the thick sections of the lifting lugs. The ratio of the cross-sectional area of the runner to the cross-sectional area of the ingates is 1.5:1-2.5:1, and the ratio of the cross-sectional area of the ingates to the maximum cross-sectional area of the thick section of the lifting lugs is 1:3-1:5.
[0007] Preferably, a transition fillet is provided at the connection between the ingate and the thick part of the lifting lug, with a radius R of 5mm to 15mm, to eliminate stress concentration.
[0008] Preferably, a locally thickened section is provided at the connection between the ingate and the thick part of the lifting lug. The thickness of the locally thickened section is 1.2 to 1.5 times the average wall thickness of the thick part of the lifting lug, and the length is 10 mm to 20 mm, which is used to delay the solidification rate at the connection.
[0009] Preferably, a slag collection bag is provided at the connection between the horizontal runner and the ingate. The slag collection bag is an arc-shaped cavity that protrudes upward on the surface of the horizontal runner and is used to collect molten slag in the molten metal.
[0010] Preferably, the inlet end of the ingate is provided with a flow-blocking section, the cross-sectional area of which is smaller than the cross-sectional area of the ingate body, and is used to adjust the flow rate of the molten metal entering the thick part of the lifting lug.
[0011] Preferably, the liquid outlet end of the ingate has a flat opening structure, and the ratio of the width to the thickness of the flat opening is 3:1 to 5:1.
[0012] Preferably, the end of the sprue is provided with an extension section, the length of which is 2 to 5 times the diameter of the sprue, for collecting cold metal and impurities at the front end of the molten metal.
[0013] A point-to-point feeding method for casting thick sections of lifting lugs using a lost-mold casting method includes the following steps: Step 1: Create a foam model of the casting and reserve the ingate connection position at the designated location of the thick part of the lifting lug; Step 2: Make a horizontal runner model using foam material. Connect four ingate models to the horizontal runner model at the positions corresponding to the thicker parts of the lifting lugs. Attach and fix the liquid outlet end of the ingate model to the ingate connection position of the thicker parts of the lifting lugs. Step 3: Combine the horizontal runner model, the ingate model, and the casting foam model into a model cluster, apply refractory coating to the model cluster, and dry it. Step 4: Place the dried model cluster in the sand box, fill it with dry quartz sand and vibrate it to shape it. Pour it under negative pressure. The molten metal enters the horizontal runner through the pouring cup and the sprue, and then directly enters the thick part of the lifting lug through the ingate to fill the mold and compensate for shrinkage. Step 5: After the casting has solidified and cooled, remove the sand, cut off the inner gate and sprue, and you will get the finished casting.
[0014] Preferably, in step three, when applying the refractory coating, a coating layer containing zircon powder is applied to the connection between the thick part of the lifting lug and the ingate. The coating layer is 0.5mm to 1.5mm thick to enhance the erosion resistance of this part.
[0015] Preferably, during the pouring process in step four, the pouring temperature is 1350℃ to 1380℃ and the negative pressure is 0.02MPa to 0.06MPa.
[0016] The beneficial effects of this invention are: 1. Significantly improve process yield: By adopting a simplified structure with a single main runner and four ingates, the redundant runners set up in the traditional scheme to meet the feeding of the lifting lugs are eliminated, the material consumption of the gating system is reduced by more than 50%, and the process yield can be increased to more than 85%.
[0017] 2. Effectively ensure the quality of lifting lug feeding: By optimizing the cross-sectional area ratio of the main gating system and the ingate, and setting transition fillets and local thickening sections at the connection between the ingate and the lifting lug, the molten metal is ensured to enter the thick part of the lifting lug at an appropriate speed and temperature, achieving precise point-to-point feeding and effectively avoiding shrinkage cavities and porosity defects.
[0018] 3. Simplified casting cleaning process: Only four ingates and a single main runner need to be removed, greatly reducing the amount of casting cleaning work and improving production efficiency.
[0019] 4. Reduced production costs: Reduced material usage in the gating system, reduced cleaning time, and increased process yield result in a significant decrease in overall production costs. Attached Figure Description
[0020] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only for this invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0021] Figure 1 This is an overall schematic diagram of the present invention; Figure 2 This is a schematic diagram of the ingate of the present invention; Figure 3 This is a schematic diagram of the casting system of the present invention during casting.
[0022] The diagram is marked as follows: 1-Pour cup, 2-Sprue, 3-Gateway, 4-Ingate, 5-Casting foam model, 6-Thick section of lifting lug, 7-Slag collection bag, 8-Extension section. Detailed Implementation
[0023] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments.
[0024] It should be noted that, unless otherwise defined, the technical or scientific terms used in this invention should have the ordinary meaning understood by one of ordinary skill in the art to which this invention pertains. The terms "first," "second," and similar terms used in this invention do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.
[0025] like Figures 1 to 3 As shown, a point-to-point feeding gating system for a solid-cast lifting lug thick section includes a pouring cup 1, a sprue 2, and a runner 3. The pouring cup 1 connects to the sprue 2, and the sprue 2 connects to the runner 3. The runner is a main gating system arranged along the length of the foam model 5 of the casting. Four ingates 4 are provided above the runner 3, directly connecting to the four corner lifting lug thick sections 6 of the foam model 5, forming a single feeding channel from the runner 3 to the lifting lug thick sections 6. By adopting a simplified structure with a single main gating system and four ingates, the redundant gating systems required for lifting lug feeding in traditional designs are eliminated. The material consumption of the gating system is reduced by more than 50%, and the process yield can be increased to over 85%.
[0026] The ratio of the cross-sectional area of the runner 3 to that of the ingate 4 is 2:1, and the ratio of the cross-sectional area of the ingate 4 to the maximum cross-sectional area of the thickened portion 6 of the lifting lug is 1:4. A transition fillet with a radius R of 10mm is provided at the connection between the ingate 4 and the thickened portion 6 of the lifting lug to eliminate stress concentration. A locally thickened section is provided at the connection between the ingate 4 and the thickened portion 6 of the lifting lug, with a thickness of 1.2 to 1.5 times the average wall thickness of the thickened portion of the lifting lug and a length of 10mm to 20mm, to slow down the solidification rate at this connection. A slag collection bag 7 is provided at the connection between the runner 3 and the ingate 4. This slag collection bag 7 is an upwardly protruding arc-shaped cavity on the surface of the runner 3, used to collect molten slag from the molten metal. By optimizing the cross-sectional area ratio of the main gating system and the ingate, and by setting transition fillets and locally thickened sections at the connection between the ingate and the lifting lug, the molten metal is ensured to directly enter the thick part of the lifting lug at a suitable speed and temperature, achieving precise point-to-point feeding and effectively avoiding shrinkage cavities and porosity defects.
[0027] The inlet end of the ingate 4 is provided with a flow-blocking section, the cross-sectional area of which is smaller than the cross-sectional area of the main body of the ingate 4, to regulate the flow rate of molten metal entering the thick part of the lifting lug. The outlet end of the ingate 4 has a flat opening structure, with a width-to-thickness ratio of 4:1, thus ensuring the stability of the pouring flow rate.
[0028] The end of the horizontal sprue 3 is provided with an extension section 8, the length of which is 2 to 5 times the diameter of the horizontal sprue 3, for collecting cold metal and impurities at the front end of the molten metal.
[0029] A point-to-point feeding method for casting thick sections of lifting lugs using a lost-mold casting method includes the following steps: Step 1: Make a foam model of the casting and reserve the connection position of the inner gate 4 at the designated position of the thick part of the lifting lug; Step 2: Make a horizontal runner 3 model using foam material. Connect four ingate models to the horizontal runner 3 model at the positions corresponding to the thick parts of the lifting lugs. Bond and fix the liquid outlet end of the ingate model to the ingate connection position of the thick parts of the lifting lugs. Step 3: Combine the horizontal runner 3 model, the ingate 4 model, and the casting foam model into a model cluster. Apply refractory coating to the model cluster and dry it. Apply a coating layer containing zircon powder to the thick part of the lifting lug and the connection between the ingate and the thick part of the lifting lug. The coating layer should be 0.5mm to 1.5mm thick to enhance the erosion resistance of this part. Step 4: Place the dried model cluster in the sand box, fill it with dry quartz sand and vibrate it to shape it. Pour it under negative pressure. The molten metal enters the horizontal runner 3 through the pouring cup and the sprue, and then directly enters the thick part of the lifting lug through the ingate 4 for filling and shrinkage compensation. The pouring temperature is 1350℃ to 1380℃ and the negative pressure is 0.02MPa to 0.06MPa. Step 5: After the casting has solidified and cooled, remove the sand, cut off the inner gate and sprue, and you will get the finished casting.
[0030] This process only requires the removal of four ingates and a single main runner, which greatly reduces the amount of casting cleaning work, improves production efficiency, reduces the material used in the runner, reduces cleaning time, increases the process yield, and significantly reduces the overall production cost.
[0031] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of the invention is limited to these examples; within the framework of the invention, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and many other variations of different aspects of the invention as described above exist, which are not provided in detail for the sake of brevity. Any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the invention should be included within the scope of protection of the invention.
Claims
1. A point-to-point feeding gating system for a heavy section casting with a lifting lug in a expendable pattern casting, comprising a sprue cup (1), a straight gate (2) and a cross gate (3), the sprue cup (1) is connected to the straight gate (2), the straight gate (2) is connected to the cross gate (3), characterized in that, The horizontal runner (3) is a main runner, which is arranged along the length of the foam model of the casting. Four ingates (4) are set above the horizontal runner (3) and are directly connected to the thick parts (6) of the lifting lugs at the four corners of the foam model of the casting, forming a single feeding channel from the horizontal runner (3) to the thick parts (6) of the lifting lugs. The ratio of the cross-sectional area of the horizontal runner (3) to the cross-sectional area of the ingate (4) is 1.5:1-2.5:1, and the ratio of the cross-sectional area of the ingate (4) to the maximum cross-sectional area of the thick parts (6) of the lifting lugs is 1:3-1:
5.
2. The point-to-point feeding gating system for the thick portion of the casting with lifting lugs in the real casting according to claim 1, characterized in that, The connection between the ingate (4) and the thick part of the lifting lug (6) is provided with a transition fillet with a radius R of 5mm to 15mm to eliminate stress concentration.
3. The point-to-point feeding gating system for the thick portion of the casting with a lifting lug as described in claim 2, characterized in that, A locally thickened section is provided at the connection between the ingate (4) and the thickened part of the lug (6). The thickness of the locally thickened section is 1.2 to 1.5 times the average wall thickness of the thickened part of the lug, and the length is 10 mm to 20 mm, which is used to delay the solidification speed at the connection.
4. The point-to-point feeding gating system for the thick portion of the casting with a lifting lug as described in claim 2, characterized in that, A slag collection bag (7) is provided at the connection between the horizontal runner (3) and the inlet (4). The slag collection bag (7) is an arc-shaped cavity that is raised upward on the surface of the horizontal runner (3) and is used to collect molten slag in the molten metal.
5. The point-to-point feeding gating system for the thick portion of the casting with a lifting lug as described in claim 3, characterized in that, The inlet end of the ingate (4) is provided with a flow-blocking section. The cross-sectional area of the flow-blocking section is smaller than the cross-sectional area of the main body of the ingate (4), which is used to adjust the flow rate of the molten metal entering the thick part of the lifting lug.
6. The point-to-point feeding gating system for the thick portion of the casting with a lifting lug as described in claim 5, characterized in that, The liquid outlet of the ingate (4) is a flat opening structure, and the ratio of the width to the thickness of the flat opening is 3:1 to 5:
1.
7. The point-to-point feeding gating system for the thick portion of the casting with a lifting lug as described in claim 1, characterized in that, The end of the horizontal runner (3) is provided with an extension section (8), the length of which is 2 to 5 times the diameter of the horizontal runner (3), for collecting cold metal and impurities at the front end of the molten metal.
8. A point-to-point feeding and pouring method for casting thick sections of lifting lugs using a solid casting process, characterized in that, Includes the following steps: Step 1: Make a foam model of the casting and reserve an inner gate (4) connection position at the set position of the thick part of the lifting lug; Step 2: Use foam material to make a horizontal runner (3) model. Connect four ingate models to the position corresponding to the thick part of the lifting lug on the horizontal runner (3) model. Bond and fix the liquid outlet end of the ingate model to the ingate connection position of the thick part of the lifting lug. Step 3: Combine the horizontal runner (3) model, the ingate (4) model, and the casting foam model into a model cluster, apply refractory coating to the model cluster and dry it; Step 4: Place the dried model cluster in the sand box, fill it with dry quartz sand and vibrate it to shape it. Pour it under negative pressure. The molten metal enters the horizontal runner (3) through the pouring cup (1) and the straight runner (2), and then directly enters the thick part of the hanging lug through the ingate (4) to fill and compensate for shrinkage. Step 5: After the casting has solidified and cooled, remove the sand, cut off the inner gate and sprue, and you will get the finished casting.
9. The point-to-point feeding and pouring method for casting thick sections of lifting lugs according to claim 1, characterized in that, When applying the refractory coating in step three, a coating layer containing zircon powder is applied to the connection between the thick part of the lifting lug and the ingate. The coating layer is 0.5mm to 1.5mm thick to enhance the erosion resistance of this part.
10. The point-to-point feeding and pouring method for casting thick sections of lifting lugs according to claim 1, characterized in that, During the pouring process in step four, the pouring temperature is 1350℃ to 1380℃, and the negative pressure is 0.02MPa to 0.06MPa.