Manufacturing tool for sand casting anti-gravity test bar
By designing a tooling system for sand casting anti-gravity test bars and combining 3D printing and anti-gravity casting processes, the problem of unstable quality during the casting process of test bars was solved, achieving high-precision and high-quality production of test bars, which is applicable to a variety of casting processes and materials.
Patent Information
- Application Number
- CN202422880383.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-25
- Publication Date
- 2025-11-25
- Estimated Expiration
- 2034-11-25
AI Technical Summary
In the existing technology, the quality of test bars manufactured by sand molds is unstable during casting, which leads to potential quality problems and affects the performance of the castings.
A tooling for fabricating anti-gravity test bars using sand casting was designed. The tooling uses a sand mold assembly, including a base, a test bar forming mold, and a stretching clamp. Combining 3D printing technology and anti-gravity casting process, it ensures that the alloy liquid fills the mold smoothly and is fully fed during solidification. The alloy liquid is effectively filled and vented through venting holes and a semi-filled groove.
It improves the molding stability and quality reliability of test bars, ensures the dimensional accuracy and internal density of castings, realizes process stability and digital control, and is applicable to a variety of casting processes and materials.
Smart Images
Figure CN223588277U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model belongs to sand casting technical field, and concretely relates to a kind of production tooling of sand casting countergravity test bar. BACKGROUND
[0002] Test bar is used for testing and evaluating casting quality in casting process, and the establishment and use of its size standard have important influence on the determination of casting quality.The length, diameter and machining precision of test bar have specific standard requirements, for example, GB / T15240 stipulates that the diameter of test bar is 4mm, 6mm and 8mm, while GB / T1804 stipulates that the diameter of test bar is 10mm, 12mm, 16mm, 20mm and 25mm.The machining precision of test bar is also very important, the maximum tolerance should be not greater than 0.02 times of the diameter of test bar, and the roughness Ra should be not greater than 0.8μm, to ensure the accuracy of test results, thereby affecting the quality and performance of casting.
[0003] At present, with the wide application of computer digital simulation technology, combined with the rapid development of 3DP (3D printing) sand mold manufacturing process technology, not only the internal quality of casting is improved, but also the dimensional accuracy of casting is improved, and the casting production cycle is effectively shortened, so the market demand has been greatly increased.In order to maintain the stability of process and the reliability of quality, the production process generally adopts countergravity casting process method, which mainly includes low pressure casting, differential pressure casting and pressure regulating casting.Countergravity process realizes digital control, and after the casting engineering alloy liquid passes through the liquid lifting pipe, it enters the mold cavity through the fiber filter, and since the bottom of the liquid lifting pipe is below the alloy liquid surface and has a certain distance from the bottom of the crucible, the high alloy quality is ensured, combined with the stable filling of countergravity casting, and the popularization of 3D printing technology, so that casting with high dimensional accuracy, good internal quality and smooth surface can be produced.
[0004] However, the test bar manufactured by the existing sand mold has unstable quality in pouring, which brings potential quality risks to the use of product, so it is of great significance to ensure the qualified rate of test bar.
[0005] Therefore, a production tooling of sand casting countergravity test bar is urgently needed. UTILITY MODEL CONTENTS
[0006] In view of the above defects in the prior art, the utility model provides a production tooling of sand casting countergravity test bar, which comprises a sand mold assembly, the test bar comprises an effective section in the middle and two stretching clamps arranged at the left and right ends of the effective section, and the sand mold assembly comprises a base and a plurality of test bar forming molds, two first rectangular through grooves are arranged at the left and right ends of the base, and the bottoms of the two first rectangular through grooves are connected in communication through connecting grooves.
[0007] The several test bar forming molds are arranged on the base from top to bottom, each test bar forming mold comprises upper and lower molds which are opposite to each other, the left and right ends of the upper and lower molds are provided with two second rectangular through grooves which are opposite to the first rectangular through grooves in the up-down direction, the bottom surface of the upper mold and the top surface of the lower mold are respectively provided with several parallel half filling grooves which are located between the two second rectangular through grooves and are communicated with the corresponding second rectangular through grooves at the left and right ends, so that the alloy liquid can be effectively filled, and the alloy liquid can be fully fed during the solidification process; the half filling groove of the upper mold is symmetrical to the half filling groove of the lower mold in the up-down direction, and the two half filling grooves can be combined into a complete filling groove, the filling groove comprises an effective segment groove cavity in the middle and two stretching chuck groove cavities arranged on the left and right sides of the effective segment groove cavity in the axial direction, the effective segment groove cavity is matched with the shape of the effective segment of the test bar, and the stretching chuck groove cavity is matched with the shape of the stretching chuck of the test bar.
[0008] Optionally, the bottom of the upper mold and the top of the lower mold are provided with step-shaped contact surfaces which match with each other.
[0009] Specifically, the bottom of the upper mold is concave, and the top of the lower mold is convex, so that the matching degree between the upper mold and the lower mold is improved, and the sealing performance of the test bar forming mold is improved.
[0010] Optionally, the total length of the filling groove is 178mm, the diameter of the effective segment groove cavity is 12mm, and the diameter of the stretching chuck groove cavity is 18mm.
[0011] Optionally, after the sand mold mold assembly is assembled, the included angle between the center axis of the filling groove and the horizontal plane is not less than 10°.
[0012] Specifically, the slag in the alloy liquid during the pouring process is conveniently discharged, air is conveniently discharged, and the process is stable.
[0013] Optionally, a plurality of exhaust holes are formed in the upper mold, and the positions of the plurality of exhaust holes correspond to the positions of the several half filling grooves, and the diameter of the exhaust hole is 6-10mm.
[0014] Specifically, the exhaust and slag discharge of the alloy liquid during the pouring process are facilitated, and the cooling effect is also achieved, the extremely cold effect of the test bar is achieved, and the mechanical properties are improved.
[0015] The utility model also includes other components which can make the production tool of the sand mold casting anti-gravity test bar normally used, and are all conventional technical means in the field. In addition, the devices or components not limited in the utility model all adopt conventional technical means in the field.
[0016] The working principle of the utility model discloses, sand mould mould assembly can adopt 3D printing technology to make, also can utilize process model to make, the raw material of sand mould mould assembly adopts 100 / 140 mesh yellow sand, and is made by the mixing solidification of 1% furan resin and 0.3% curing agent of yellow sand ratio.In the pouring, first, sand mould mould assembly is assembled, then the sprue cup is installed to the connecting slot mouth at the bottom of pedestal bottom, then the box is assembled, and the top is locked and reinforced, alloy liquid is poured into sand mould mould assembly from the sprue cup at the bottom through the anti-gravity pouring process, and alloy liquid is filled into the filling groove of each layer through the first rectangular through slot and the second rectangular through slot;After cooling, remove sand mould mould assembly, cut the test bar, and the remaining alloy solidification body can be remelted and recast.
[0017] The utility model discloses the beneficial effect is:
[0018] 1. The process stability of this tool manufacturing process is reliable, and the quality of the test bar produced is reliable.
[0019] 2. The alloy liquid is filled by adopting the anti-gravity pouring process, and the filling is stable, which is beneficial to reduce the inclusion into the cavity of the tool;At the same time, the filling pressure is throughout the whole process of crystallization and solidification, which is the main power of shrinkage cavity and shrinkage porosity, and the organization compactness is improved.
[0020] 3. The tool realizes digital control in the whole pouring process, guarantees the consistency of process parameters, and realizes the stability and reliability of product quality.
[0021] 4. The raw materials of the tool are yellow sand, furan resin and curing agent, which are convenient to make and assemble, simple, reliable and stable to operate, can be stacked, and the production efficiency is improved;At the same time, the raw material cost is low, easy to obtain, simple to make and convenient to operate.
[0022] 5. The tool can be made by process model or 3DP, so the sand mold interchangeability is good, and the positioning is accurate.
[0023] 6. The tool can be applied to low-pressure casting, differential pressure casting, pressure-adjusting casting and other processes.
[0024] 7. The tool can be used for making test bars of different materials such as aluminum-silicon alloy, aluminum-copper alloy and magnesium alloy, and has wide application range. DRAWINGS
[0025] The utility model will be further described below in combination with the drawings and examples.
[0026] Figure 1 It is the whole structure schematic diagram of the utility model.
[0027] Figure 2 It is Figure 1 The explosion map.
[0028] Figure 3 It is the explosion map of the test bar forming die of the utility model.
[0029] Figure 4 It is the bottom structure schematic view of the base of the utility model.
[0030] Figure 5 It is the structure schematic view of the process model for making the sand mold die assembly in the embodiment.
[0031] In the figure: 1. base, 2. test bar forming die, 3. first rectangular through slot, 4. connecting slot, 5. upper die, 6. lower die, 7. second rectangular through slot, 8. half filling slot, 9. effective section slot cavity, 10. stretching chuck slot cavity, 11. exhaust hole. DETAILED DESCRIPTION
[0032] The utility model is clearly described below in combination with the drawings and specific embodiments in the embodiment of the utility model, and the description herein is only used to explain the utility model, but not as the limitation of the utility model. Based on the embodiment in the utility model, all other embodiments obtained by the person skilled in the art without creative labor, any modification, equivalent replacement, improvement, etc. should be included in the protection scope of the utility model.
[0033] EMBODIMENT
[0034] As Figures 1-4 shown, the utility model embodiment provides a kind of production tool of sand mold casting countergravity test bar, including sand mold die assembly, the test bar includes the effective section of middle part and the two stretching chucks of two ends of effective section left and right, sand mold die assembly includes base 1 and two test bar forming dies 2, and the left and right ends of base 1 are provided with two first rectangular through slots 3 that pass through up and down, and the bottom of two first rectangular through slots 3 is connected by connecting slot 4.
[0035] Two test bar forming molds 2 are arranged on the base 1 in an up-down manner, each test bar forming mold 2 comprises an upper mold 5 and a lower mold 6 arranged oppositely in an up-down manner, the left and right ends of the upper mold 5 and the lower mold 6 are provided with two second rectangular through grooves 7 arranged oppositely in an up-down manner, and the second rectangular through grooves 7 are arranged oppositely in an up-down manner with the first rectangular through grooves 3, six parallel half filling grooves 8 are arranged on the bottom surface of the upper mold 5 and the top surface of the lower mold 6 respectively, the half filling grooves 8 are located between the two second rectangular through grooves 7, and the left and right ends of the half filling grooves 8 are communicated with the corresponding side second rectangular through grooves 7 respectively, so that the alloy liquid can be effectively filled, and the alloy liquid can be fully fed during the solidification process; the half filling grooves 8 of the upper mold 5 are symmetrical with the half filling grooves 8 of the lower mold 6 in an up-down manner, the two half filling grooves 8 can be combined into a complete filling groove, the filling groove comprises an effective segment groove cavity 9 in the middle and two stretching chuck groove cavities 10 arranged on the left and right sides of the effective segment groove cavity 9 in an axial direction, the effective segment groove cavity 9 is matched with the shape of the effective segment of the test bar, and the stretching chuck groove cavities 10 are matched with the shape of the stretching chuck of the test bar, the total length of the filling groove is 178mm, the diameter of the effective segment groove cavity 9 is 12mm, and the diameter of the stretching chuck groove cavity 10 is 18mm.
[0036] In addition, the bottom of the upper mold 5 and the top of the lower mold 6 are provided with mutually matching stepped contact surfaces, the bottom of the upper mold 5 is concave, and the top of the lower mold 6 is convex, so that the matching degree between the upper mold 5 and the lower mold 6 is improved, and the sealing performance of the test bar forming mold 2 is improved. A plurality of exhaust holes 11 are formed in the upper mold 5, and the positions of the plurality of exhaust holes 11 correspond to the positions of the six half filling grooves 8 respectively, the diameter of the exhaust hole 11 is 8mm, so that the exhaust and deslagging of the alloy liquid during the pouring process are facilitated, and the cooling effect is also achieved, the extremely cold effect of the test bar is realized, and the mechanical properties are improved.
[0037] In addition, after the sand mold mold assembly is assembled, the included angle between the center axis of the filling groove and the horizontal plane is not less than 10°, so that the deslagging of the alloy liquid during the pouring process is facilitated, and the exhaust is also facilitated, and the stability of the process is realized.
[0038] The working principle of the utility model is that the sand mold mold assembly can be manufactured by using a process model, the process model is as follows Figure 5As shown, the two layers on the process model are matched with the shape of the test bar, and the bottom is an H-shaped structure matched with the two first rectangular through grooves 3 and the connecting notch 4 of the base 1; the raw material of the sand mold assembly is 100 / 140 mesh yellow sand, which is made by mixing and curing 1% furan resin and 0.3% curing agent in the yellow sand. When pouring, first assemble the sand mold assembly, then install the sprue cup at the connecting notch 4 at the bottom of the base 1, then box, and tighten and reinforce the top, pour the alloy liquid into the sand mold assembly from the bottom sprue cup through the anti-gravity pouring process, and the alloy liquid fills into the filling groove of each layer through the first rectangular through groove 3 and the second rectangular through groove 7; after cooling, remove the sand mold assembly, cut off the test bar, and the remaining alloy solidification body can be remelted and reused.
[0039] The above has described the embodiments of the present application, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes are obvious to those skilled in the art without departing from the scope and spirit of the described embodiments.
Claims
1. A sand casting countergravity test bar making tooling comprising a sand mold assembly, the test bar comprising a central useful section and two tensile collets disposed at either end of the useful section, characterized by: The sand mold assembly comprises a base and a plurality of test bar forming molds, two first rectangular through grooves are arranged at the left and right ends of the base in a penetrating manner from top to bottom, and the bottoms of the two first rectangular through grooves are connected in communication through a connecting groove; The plurality of test bar forming molds are arranged on the base in sequence from top to bottom, each test bar forming mold comprises an upper mold and a lower mold arranged oppositely, two second rectangular through grooves are arranged at the left and right ends of the upper mold and the lower mold in a penetrating manner from top to bottom, a plurality of parallel semi-filling grooves are arranged on the bottom surface of the upper mold and the top surface of the lower mold respectively, the semi-filling grooves are located between the two second rectangular through grooves and are in communication with the second rectangular through grooves on the corresponding sides respectively, the semi-filling grooves of the upper mold and the semi-filling grooves of the lower mold are symmetrical in the vertical direction, the two semi-filling grooves can be combined into a complete filling groove, the filling groove comprises an effective segment groove cavity in the middle and two stretch chuck groove cavities arranged on the left and right sides of the effective segment groove cavity in the axial direction, the effective segment groove cavity is matched with the shape of the effective segment of the test bar, and the stretch chuck groove cavities are matched with the shape of the stretch chucks of the test bar.
2. The sand casting countergravity test bar production tooling of claim 1, wherein: The bottom of the upper mold and the top of the lower mold are provided with step-shaped contact surfaces that match with each other.
3. The sand casting countergravity test bar production tooling of claim 2, wherein: The total length of the filling groove is 178 mm, the diameter of the effective segment groove cavity is 12 mm, and the diameter of the stretch chuck groove cavity is 18 mm.
4. The sand casting countergravity test bar production tooling of claim 3, wherein: The included angle between the central axis of the filling groove and the horizontal plane is not less than 10°.
5. The sand casting countergravity test bar production tooling of claim 4, wherein: A plurality of exhaust holes are arranged on the upper mold, and the positions of the plurality of exhaust holes correspond to the positions of the plurality of semi-filling grooves respectively, and the diameter of the exhaust hole is 6-10 mm.