A U-shaped variable cross-section pouring cup and gravity casting metal mold

Abstract

This invention discloses a U-shaped variable cross-section pouring cup and a gravity casting metal mold, comprising an inlet area, a first arc-shaped descending area, an arc-shaped ascending area, a second arc-shaped descending area, and a sprue connected in sequence. This pouring cup can improve the quality of castings.

Description

Technical Field

[0001] This invention belongs to the field of casting mold structure design technology, and relates to a U-shaped variable cross-section pouring cup and a gravity casting metal mold. Background Technology

[0002] The gating system is the channel through which molten metal flows into the mold cavity. It typically consists of units such as the pouring cup, sprue, sprue holder, runner, and ingate. The pouring cup's function is to receive the molten metal from the ladle and guide it into the sprue. The sprue's function is to guide the molten metal from the pouring cup into the runner, establishing a sufficient pressure head to allow the molten metal to overcome flow resistance under gravity and fill the mold cavity promptly. The sprue holder buffers the molten metal from the sprue, shortening the turbulence zone at the sprue-runner corner and improving the pressure distribution within the runner. The runner's function, besides guiding the molten metal into the ingate, is primarily for skimming slag. Traditional gravity mold casting uses a funnel-shaped pouring cup, such as... Figure 1 As shown. A drawback of traditional pouring cups is that the pouring process is highly susceptible to human error. The skill levels and operating habits of different pouring workers, and even different working conditions of the same pouring worker, can lead to instability in the aluminum molten metal flow field when pouring the same casting, resulting in fluctuations in casting quality. The housings used in aero-engine fuel accessories are mostly aluminum alloy parts, the vast majority of which are cast. The design places high demands on the internal quality of these parts, especially regarding gas and slag porosity defects. Aero-engine castings have strict requirements on the quantity and size of these casting defects; if they exceed the acceptable range, welding repair is not allowed, and the parts are scrapped. Therefore, producing high-quality castings with few or even no gas and slag porosity defects in their internal structure has become a pressing technical challenge. Summary of the Invention

[0003] The purpose of this invention is to overcome the shortcomings of the prior art and provide a U-shaped variable cross-section pouring cup and a gravity casting metal mold, which can improve the quality of castings.

[0004] To achieve the above objectives, the present invention discloses a U-shaped variable cross-section pouring cup, comprising an inlet area, a first arc-shaped descending area, an arc-shaped ascending area, a second arc-shaped descending area, and a sprue that are connected in sequence.

[0005] A further improvement of the U-shaped variable cross-section pouring cup of the present invention is as follows:

[0006] Furthermore, the inlet area includes a cylindrical gate and a transition area with an inverted frustum structure, wherein the lower end of the gate is connected to the upper end of the transition area, and the lower end of the transition area is connected to the first arc-shaped descending area.

[0007] Further, the diameter of the pouring inlet is greater than ΦM, the height of the pouring inlet is greater than or equal to 50mm, the diameter of the upper end surface of the transition zone is ΦM, and the diameter of the lower end surface of the transition zone is 2.2Φ 直 -2.5Φ 直 , the height of the transition zone is H M , and the slope of the side wall of the transition zone is 5°-8°.

[0008] Further, the first arc-shaped descending zone is a 1 / 4 annular pipe.

[0009] Further, the diameter of the first arc-shaped descending zone is 2Φ 直 -2.3Φ 直 .

[0010] Further, the axis of the arc-shaped ascending zone is consistent with y=10sin15x, 0

[0011] Further, the diameter of one end of the arc-shaped ascending zone connected with the first arc-shaped descending zone is 2Φ 直 -2.3Φ 直 , and the diameter of the other end of the arc-shaped ascending zone is 1.2Φ 直 -1.5Φ 直 .

[0012] Further, the diameter of the arc-shaped ascending zone gradually decreases along the flow direction of the filtrate.

[0013] Further, the second arc-shaped descending zone is a 1 / 4 circular annular structure with a radius of 4Φ 直 , and the diameter of the cross section of the second arc-shaped descending zone is 1.2Φ 直 -1.5Φ 直 .

[0014] The application discloses a gravity casting metal mold, which comprises a U-shaped variable cross-section pouring cup.

[0015] The application has the following beneficial effects:

[0016] In the specific operation of the U-shaped variable cross-section pouring cup and the gravity casting metal mold, the inlet zone, the first arc-shaped descending zone, the arc-shaped ascending zone, the second arc-shaped descending zone and the direct sprue are sequentially connected, the molten aluminum enters the pouring cup from a ladle, the flow field is stable when the molten aluminum flows into the direct sprue inlet from the pouring cup, the influence of artificial factors on the filling of the molten aluminum in the pouring system and the mold cavity during pouring is minimized, the gas entrainment and turbulence during the filling of the molten aluminum are avoided, the probability of the generation of invasive pores and oxidized slag defects is reduced, and the purpose of improving the quality of the castings is achieved. BRIEF DESCRIPTION OF DRAWINGS

[0017] The accompanying drawings, which form a part of this specification, are included to provide a further understanding of the application and are incorporated in and constitute a part of this specification. The embodiments of the application, and their

[0018] Figure 1 is a structural diagram of the prior art;

[0019] Figure 2a is a structural diagram of the gate cup in the present application;

[0020] Figure 2b is a plan view of the gate cup in the present application;

[0021] Figure 3 is a structural diagram of a conventional gate cup metal mold;

[0022] Figure 4 is a structural diagram of the gravity casting metal mold in the present application;

[0023] Figure 5 is a simulation diagram of the gate cup described in the present application. DETAILED DESCRIPTION

[0024] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are some but not all of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0025] In the description of the present application, it should be understood that the terms "comprising" and "including" indicate the presence of described features, integers, steps, operations, elements, and / or components, but do not exclude one or more other features, integers, steps, operations, elements, components, and / or sets thereof.

[0026] It should also be understood that the terms used in the specification of the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application. As used in the specification and the appended claims of the present application, unless otherwise clearly indicated by the context, the singular forms "a", "an" and "the" are intended to include the plural forms.

[0027] It should be further understood that the term "and / or" used in the specification and the appended claims of the present application means any combination of one or more of the associated listed items and all possible combinations thereof, and includes these combinations, for example, A and / or B can represent three cases of A alone, A and B together, and B alone. In addition, the character " / " in the present application generally represents an "or" relationship between the front and rear associated objects.

[0028] It should be understood that, although the terms first, second, third, etc. can be employed in describing the preset ranges, etc. in the embodiments of the present application, the preset ranges should not be limited to these terms. These terms are only used to distinguish the preset ranges from each other. For example, the first preset range can also be referred to as the second preset range, and similarly, the second preset range can also be referred to as the first preset range, without departing from the scope of the embodiments of the present application.

[0029] Depending on the context, the word "if" as used herein can be interpreted to mean "when" or "while" or "in response to determining" or "in response to detecting." Similarly, the phrase "if it is determined" or "if a stated condition or event occurs" can be interpreted to mean "when it is determined" or "in response to determining" or "when a stated condition or event occurs" or "in response to detecting a stated condition or event."

[0030] In order to make the purposes, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are some of the embodiments of the present application, rather than all the embodiments of the present application. The components of the embodiments of the present application described and shown in the drawings herein can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the claimed present application, but only represents selected embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art without creative efforts based on the embodiments in the present application belong to the scope of protection of the present application.

[0031] Various structural schematic diagrams according to the disclosed embodiments of the present application are shown in the drawings. These diagrams are not drawn to scale, in which some details are exaggerated for the purpose of clarity and some details can be omitted. The shapes of various regions, layers and their relative sizes and positional relationships shown in the diagrams are only exemplary, and in actuality, there can be deviations due to manufacturing tolerances or technical limitations, and regions / layers with different shapes, sizes and relative positions can be additionally designed by those skilled in the art according to actual needs.

[0032] Embodiment one

[0033] The U-shaped variable cross-section gate cup described in the present application comprises an inlet zone, a first arc-shaped descending zone, an arc-shaped ascending zone, a second arc-shaped descending zone and a straight sprue in sequence;

[0034] The inlet zone comprises a cylindrical inlet and a transition zone with a rounded platform structure, wherein the lower end of the inlet communicates with the upper end of the transition zone, the lower end of the transition zone communicates with the first arc-shaped descending zone, the diameter of the inlet is greater than ΦM, the height of the inlet is greater than or equal to 50 mm, the upper end surface of the transition zone has a diameter of ΦM, and the lower end surface of the transition zone has a diameter of 2.2Φ 直 -2.5Φ 直 The height of the transition zone is H M The slope of the side wall of the transition zone is 5°-8°, so that the transition zone can establish sufficient pressure head to enable the molten aluminum to overcome the flow resistance under the action of gravity and timely fill the high point of the joint between the arc-shaped ascending zone and the second arc-shaped descending zone, thereby preventing the occurrence of air entrainment. The purpose of designing the variable cross-section at the pouring line is to facilitate observation by the pouring operator. During the pouring process, after the molten aluminum reaches the pouring line, the molten aluminum surface must be above the pouring line until the end of pouring.

[0035] The first arc-shaped descending zone is a 1 / 4 annular pipe, the diameter of the first arc-shaped descending zone is 2Φ 直 -2.3Φ 直 The center line profile of the first arc-shaped descending zone is a 1 / 4 circle with a radius of 4Φ 直 located in the third quadrant. The first arc-shaped descending zone is used to store the molten aluminum from the inlet zone. The first arc-shaped descending zone and the arc-shaped ascending zone form a U-shaped pipe. After reaching a suitable liquid level, the molten aluminum will flow into the second arc-shaped descending zone. The advantage of the U-shaped pipe is that there is no air entrainment as long as the molten aluminum is in a full state.

[0036] The arc-shaped ascending zone has an axis that conforms to y=10sin15x (0 直 -2.3Φ 直 The diameter of the other end of the arc-shaped ascending zone is 1.2Φ 直 -1.5Φ 直 The diameter of the arc-shaped ascending zone gradually decreases along the flow direction of the filtrate, i.e., a variable cross-section structure is adopted. The purpose of designing the variable cross-section is: 1) the molten aluminum is in a pressurized flow state, making it easy to fill the pouring system; 2) it can prevent the generation of horizontal vortexes that induce vertical vortexes, thereby preventing the introduction of air bubbles into the sprue; and 3) it reduces the pouring state of the pouring operator.

[0037] In operation, the arc-shaped ascending zone and the first arc-shaped descending zone together function as a "storage tank". When the molten aluminum is stored to a certain amount, it flows into the straight sprue through the second arc-shaped descending zone. The arc-shaped ascending zone and the first arc-shaped descending zone have a certain buffering effect on the molten aluminum during filling, which slows down the flow speed of the molten aluminum and reduces the adverse effects of splashing and turbulence of the molten aluminum.

[0038] Second arc-shaped descending zone: the arc-shaped ascending zone is connected with the sprue through the second arc-shaped descending zone, which plays an intermediate transition role. The purpose of the second arc-shaped descending zone is to introduce the molten aluminum in the arc-shaped ascending zone into the sprue. The splashing phenomenon is avoided during the filling process of the molten aluminum, and then the gas entrainment and the resulting oxidation slag defects are avoided. Therefore, the second arc-shaped descending zone is a 1 / 4 circular ring structure with a radius of 4Φ 直 / 4 of the diameter of the arc-shaped ascending zone, and is located in the first quadrant. The common tangent at the connection between the second arc-shaped descending zone and the arc-shaped ascending zone is a horizontal line. This design can ensure the smooth flow of the molten aluminum and avoid gas entrainment. The diameter is designed to be 1.2Φ 直 -1.5Φ 直 The purpose is to enable the molten aluminum to quickly fill the sprue.

[0039] It should be noted that when the molten aluminum flows from the pouring basin into the sprue cup and then flows into the inlet of the sprue, the flow field is stable when the molten aluminum enters the inlet of the sprue from the end of the sprue cup. The influence of human factors on the filling of the molten aluminum in the pouring system and the mold cavity during the pouring process is minimized. The gas entrainment and turbulence during the filling process of the molten aluminum are avoided, and the probability of the generation of invasive pores and oxidation slag defects is reduced. Finally, the purpose of improving the quality of the casting is achieved.

[0040] Example two

[0041] The sprue cup of the gravity pouring metal mold is connected to the mold through a countersunk screw, as shown in Figure 3 a. The inner cavity shape is shown in Figure 3 b. During production preparation, the traditional sprue cup is removed from the mold, and then the new sprue cup is installed through the countersunk screw. The installation position of the new sprue cup on the mold is determined by the coincidence of the center of the end of the new sprue cup and the center of the upper end of the sprue. The outer shape of the mold and the inner cavity diagram of the mold after replacing the new sprue cup are shown in Figure 4 a and Figure 4 b.

[0042] After installation, the old coating on the mold cavity and the parting surface is removed by a dry ice cleaning machine. The mold is preheated to 200-300℃, and then ZnO coating is sprayed on the mold pouring system and the mold cavity part. The spraying is uniform and 2-3 times. The prepared mold is installed on the two-opening gravity pouring machine. The aluminum liquid is poured into the upper end of the new sprue cup through the pouring basin, and then flows into the entire cavity. Finally, the mold is opened after the casting solidifies, and the casting is taken out, completing the entire pouring process.

[0043] Since the actual filling process of molten aluminum in the pouring cup and runner cannot be directly observed, it can only be visualized and analyzed in casting simulation software. The filling simulation results from Anycasting software show that, after using this invention, air is continuously trapped in the runner from the initial filling of the molten aluminum until it reaches the pouring cup. Figure 5 As shown in a, b, and c, when the molten aluminum just fills the casting cavity, the new type of pouring cup and the entire gating system are already rapidly filled with molten aluminum, and this state of fullness is maintained until the end of the entire filling process. Figure 5 As shown in e, f, and g, this demonstrates the rational design of the present invention, enabling molten aluminum to quickly fill the entire gating system, preventing the generation of intrusive gases, and thus significantly reducing the probability of porosity in the casting and improving the casting yield. Furthermore, the speed simulation results show that after the filtrate fills the new gating cup, the filling speed of the filtrate at the end of the gating cup is very low (shown in green). This avoids turbulence in the filtrate at this point, thereby reducing the occurrence of air entrapment.

[0044] In summary, this invention not only enables molten aluminum to quickly fill the entire flow channel, but also slows down the filling speed of the molten aluminum, ultimately significantly reducing the probability of porosity defects in the casting.

[0045] It should be noted that the quality of castings produced using traditional pouring cups fluctuates greatly, with an annual scrap rate of approximately 50% due to internal slag porosity defects. After using this invention, the quality of castings produced has been significantly improved, with the scrap rate due to internal slag porosity reduced to only about 10%. The resulting cost savings from improved quality amount to over two hundred thousand yuan annually. Furthermore, this design concept can be extended to other castings, significantly improving the pass rate of similar castings.

[0046] Example 3

[0047] The gravity casting metal mold of this invention includes a U-shaped variable cross-section gating cup, wherein the U-shaped variable cross-section gating cup includes an inlet area, a first arc-shaped descending area, an arc-shaped ascending area, a second arc-shaped descending area, and a sprue that are connected in sequence; the inlet area includes a cylindrical gate and a transition area with an inverted frustum structure, wherein the lower end of the gate is connected to the upper end of the transition area, and the lower end of the transition area is connected to the first arc-shaped descending area; the diameter of the gate is greater than ΦM, the height of the gate is greater than or equal to 50mm, the diameter of the upper end face of the transition area is ΦM, and the diameter of the lower end face of the transition area is 2.2Φ 直 -2.5Φ 直 The height of the transition region is H. M The slope of the sidewall of the transition zone is 5°-8°; the first arc-shaped descending zone is a 1 / 4 annular pipe; the diameter of the first arc-shaped descending zone is 2Φ. 直 -2.3Φ 直; the axis of the arc-shaped rising region is consistent with y=10sin15x, 0 直 -2.3Φ 直 , the diameter of the other end of the arc-shaped rising region is 1.2Φ 直 -1.5Φ 直 ; the diameter of the arc-shaped rising region gradually decreases along the flow direction of the filtrate; the second arc-shaped descending region is a 1 / 4 circular ring structure with a radius of 4Φ 直 , and the diameter of the cross section of the second arc-shaped descending region is 1.2Φ 直 -1.5Φ 直 .

[0048] Other embodiments of the application will be apparent to those skilled in the art from consideration of the specification and practice of the application disclosed herein. It is intended that the specification and examples be considered as exemplary only, with the true scope and spirit of the application being indicated by the following claims.

[0049] It is to be understood that the application is not limited to the specific structures described herein and illustrated in the accompanying drawings, and that since the general principles of the application have been used to facilitate a complete understanding of the application, various modifications can be made to the application without departing from the scope of the claims. The scope of the application is to be limited only by the claims.

[0050] The above description is only the preferred embodiment of the present application, not any limitation to the present application, any simple modification, change and equivalent structure change according to the technical essence of the present application to the above embodiment, still belongs to the protection scope of the technical scheme of the present application.

Claims

1. A U-shaped cross-section gate cup characterized in that, The inlet zone, the first arc-shaped descending zone, the arc-shaped ascending zone, the second arc-shaped descending zone and the sprue gate are connected in sequence. The inlet zone comprises a cylindrical pouring inlet and a transition zone with a rounded table structure, wherein the lower end of the pouring inlet is connected with the upper end of the transition zone, and the lower end of the transition zone is connected with the first arc-shaped descending zone. The first arc-shaped descending zone is a 1 / 4 annular pipeline. The diameter of the arc-shaped ascending zone gradually decreases along the flow direction of the filtrate.

2. The U-shaped variable cross-section gate cup according to claim 1, characterized in that The diameter of the pouring gate is greater than ΦM, the height of the pouring gate is greater than or equal to 50 mm, the diameter of the upper end surface of the transition zone is ΦM, and the diameter of the lower end surface of the transition zone is 2.2Φ 直 -2.5Φ 直 The height of the transition zone is H M The slope of the side wall of the transition zone is 5°-8°.

3. The U-shaped cross-section gate cup according to claim 2, characterized in that the diameter of the first arc-shaped descending region is 2Φ 直 -2.3Φ 直 .

4. The U-shaped variable cross-section gate cup of claim 1, wherein, The axis of the arc-shaped ascending zone is consistent with y=10sin15x, 0 5. The U-shaped cross-section gate cup according to claim 4, characterized in that The diameter of the end of the arc-shaped ascending region connected with the first arc-shaped descending region is 2Φ 直 -2.3Φ 直 The diameter of the other end of the arc-shaped ascending region is 1.2Φ 直 -1.5Φ 直 .

6. The U-shaped variable cross-section gate cup of claim 2, wherein, The second arc-shaped descending area is a 1 / 4 circular ring structure with a radius of 4Φ 直 , and the diameter of the cross section of the second arc-shaped descending area is 1.2Φ 直 -1.5Φ 直 .

7. A gravity casting metal mold characterized by comprising: The U-shaped variable cross-section gate cup of any one of claims 1-6.

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