Pouring system for bowl-shaped castings

Abstract

The utility model provides a pouring system for bowl-shaped castings, which comprises a cavity, a sprue is arranged below the cavity, a first-layer cross gate and a second-layer cross gate are sequentially arranged between the sprue and the cavity from bottom to top, a first-layer cylindrical vertical gate is communicated between the first-layer cross gate and the second-layer cross gate, and a second-layer cylindrical vertical gate is communicated between the second-layer cross gate and the first-layer cylindrical vertical gate. A second-layer cylindrical flow gate communicated with the cavity is arranged on the second-layer cross gate in a communicating manner; by means of the double-layer cross gate structure, mold filling of molten metal is stable, gas entrapment and secondary oxidation are prevented, the bottom of the cavity is prevented from being directly connected with the straight gate, the temperature of the molten metal in all the pouring gates is more uniform, the temperature of the molten metal in all the pouring gates is more uniform, and the temperature of the molten metal in all the pouring gates is more uniform. Local overheating is avoided to a certain extent, the casting defects of shrinkage cavities, looseness, air holes, slag inclusion and the like in the prior art are overcome, and stable casting quality during batch production is guaranteed.

Description

Technical Field

[0001] The utility model relates to the field of sand casting, in particular to a pouring system for bowl-shaped castings. Background Art

[0002] Bowl-shaped structural castings are mainly used in products such as ships and torpedoes. They are characterized by relatively thick walls, processed surfaces, and most of the internal areas are not processed, or only partially processed. In the casting process of bowl-shaped castings, there are problems in the prior art: shrinkage cavities, looseness, pores caused by air entrainment, slag inclusions and other defects are easily generated, and pinholes and coarse grains are easily generated at the bottom hot spot when the alloy liquid pinhole test is qualified.

[0003] This patent is mainly aimed at the research of bowl-shaped castings with specifications of SR400~SR800mm. At present, the traditional casting process design is generally low-pressure or differential pressure sand casting, the bottom runner is a single layer (sometimes the bottom runner is designed as a heat storage stabilizer), and the periphery adopts a gap gate. This design has its limitations. If the bottom runner is designed as a single layer, due to the fast filling, it is easy to produce defects such as air entrainment and slag. If the runner is designed at the lowest point of the product, since the inner gate is directly connected to the straight runner, although the shrinkage compensation effect is good, it is easy to produce defects such as pinholes due to slow solidification. If the runner is not designed at the lowest point of the product, the slag formed during the filling process may not be discharged. If the bottom runner is designed as a heat storage stabilizer, it will also increase the tendency of bell holes. In addition, if only the gap runner is designed around the casting, and the riser is not designed on the top, defects such as pores may occur locally due to poor exhaust. Utility Model Content

[0004] The technical problem to be solved by the utility model is that the prior art bowl-shaped castings have casting defects such as shrinkage cavities, looseness, air holes, slag inclusions, etc. The utility model provides a pouring system for bowl-shaped castings to solve the above problems.

[0005] The technical solution adopted by the utility model to solve its technical problems is: a pouring system for a bowl-shaped casting, including a cavity, a straight runner is arranged below the cavity, a first layer of horizontal runner and a second layer of horizontal runner are arranged in sequence from bottom to top between the straight runner and the cavity, the straight runner is connected to the first layer of horizontal runner, a first layer of cylindrical vertical runner is connected between the first layer of horizontal runner and the second layer of horizontal runner, and a second layer of cylindrical inner gate connected to the cavity is connected on the second layer of horizontal runner; an annular riser is arranged above the cavity, and a conformal straight runner is connected between the second layer of horizontal runner and the annular riser.

[0006] Furthermore: the structure of the first layer of horizontal runner is a cross-shaped structure; the structure of the second layer of horizontal runner is a combined structure, whose outer circle is annular and the inner part is a cross-shaped structure; the number of the first layer of cylindrical vertical runners is four, which are arranged along the cross-shaped structure of the first layer of horizontal runner and the second layer of horizontal runner.

[0007] Furthermore: the cross-sectional area of ​​the first layer of horizontal runner = (0.8-1.0) × the cross-sectional area of ​​the straight runner; the cross-sectional area of ​​the first layer of cylindrical vertical runner = the cross-sectional area of ​​the first layer of horizontal runner; the cross-sectional area of ​​the first layer of horizontal runner = the cross-sectional area of ​​the second layer of horizontal runner; the diameter of the second layer of cylindrical ingates = the diameter of the conformal straight runner = (4-6) × the average wall thickness of the cavity.

[0008] Furthermore: the conformal sprue is connected to the cavity through a gap ingate; a necking riser is arranged between the annular riser and the conformal sprue.

[0009] Furthermore: chillers are provided at the bottom and the outer side walls of the cavity.

[0010] The beneficial effect of the utility model is that the pouring system of the bowl-shaped casting of the utility model creatively adds a double-layer cross runner structure, so that the filling of the molten metal is stable, and air entrainment and secondary oxidation are prevented. The bottom of the cavity avoids direct connection with the straight runner, so that the temperature of the molten metal in each runner is more uniform, and local overheating is avoided to a certain extent. At the same time, eight cold irons are arranged around the gate in the bottom cavity, which effectively suppresses the tendency of pinholes and coarse grains due to overheating; at the same time, an annular riser is arranged on the top, which enhances the shrinkage compensation effect of the riser, reduces the number of follow-type straight runners, and makes the exhaust of the cavity smoother, overcomes the casting defects such as shrinkage holes, looseness, air holes, slag inclusions, etc. in the prior art, and ensures stable casting quality during mass production. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The utility model is further described below in conjunction with the accompanying drawings and embodiments.

[0012] Figure 1 It is a structural schematic diagram of the utility model;

[0013] Figure 2 It is the CC section view.

[0014] In the figure, 1 is the cavity, 2 is the straight runner, 3 is the first layer of the horizontal runner, 4 is the second layer of the horizontal runner, 5 is the first layer of the cylindrical vertical runner, 6 is the second layer of the cylindrical gate, 7 is the annular riser, 8 is the conformal straight runner, 9 is the gap gate, 10 is the necking riser, and 11 is the chiller. DETAILED DESCRIPTION

[0015] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention. On the contrary, the embodiments of the present invention include all changes, modifications and equivalents that fall within the spirit and connotation of the appended claims.

[0016] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0017] In addition, the terms "first", "second", etc. are used for descriptive purposes only and are not to be understood as indicating or implying relative importance. In the description of the present utility model, it should be noted that, unless otherwise clearly specified and limited, the terms "connected" and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances. In addition, in the description of the present utility model, unless otherwise specified, "multiple" means two or more.

[0018] Any process or method description in the flowchart or otherwise described herein may be understood to represent a module, fragment or portion of code that includes one or more executable instructions for implementing the steps of a specific logical function or process, and the scope of the preferred embodiments of the present invention includes alternative implementations in which functions may not be performed in the order shown or discussed, including performing functions in a substantially simultaneous manner or in the reverse order depending on the functions involved, which should be understood by technicians in the technical field to which the embodiments of the present invention belong.

[0019] like Figure 1 to Figure 2As shown, the utility model provides a pouring system for bowl-shaped castings, including a cavity 1, a sprue 2 is arranged below the cavity 1, a first-layer runner 3 and a second-layer runner 4 are arranged from bottom to top between the sprue 2 and the cavity 1, the sprue 2 is connected to the first-layer runner 3, a first-layer cylindrical vertical runner 5 is arranged between the first-layer runner 3 and the second-layer runner 4, a second-layer cylindrical endogate 6 connected to the cavity 1 is arranged on the second-layer runner 4; an annular riser 7 is arranged above the cavity 1, and a conformal sprue 8 is arranged between the second-layer runner 4 and the annular riser 7.

[0020] The structure of the first-layer runner 3 is a cross-shaped structure; the structure of the second-layer runner 4 is a combined structure, with an annular outer ring and a cross-shaped structure inside; the number of the first-layer cylindrical vertical runners 5 is four, which are arranged along the cross-shaped structure of the first-layer runner 3 and the second-layer runner 4.

[0021] The cross-sectional area of ​​the first layer of horizontal runner 3 = 0.8-1.0 × the cross-sectional area of ​​the straight runner 2; the cross-sectional area of ​​the first layer of cylindrical vertical runner 5 = the cross-sectional area of ​​the first layer of horizontal runner 3; the cross-sectional area of ​​the first layer of horizontal runner 3 = the cross-sectional area of ​​the second layer of horizontal runner 4; the diameter of the second layer of cylindrical endogate 6 = the diameter of the conformal straight runner 8 = 4-6 × the average wall thickness of the cavity 1.

[0022] The technical solution disclosed in the present application can be applied to SR400~SR800mm bowl-shaped castings. In order to overcome the defects of existing bowl-shaped castings during the casting process, such as shrinkage cavities, looseness, pores caused by air entanglement, slag inclusions, and pinholes and coarse grains that are prone to occur at the bottom hot node, the technical solution of the present application is to adopt a double-layer cross runner structure between the straight runner 2 and the cavity 1. After passing through the straight runner 2, the molten metal first enters the first layer of the cross runner 3 for buffering, and the rising speed of the molten metal level is slowed down, which completely avoids the possibility of air entanglement and secondary oxidation.

[0023] When the molten metal level rises, it enters the second layer of runner 4 again to fill the mold smoothly, which can make the molten metal fill the mold smoothly, prevent air entrainment and secondary oxidation, and the bottom of the cavity 1 avoids direct connection with the sprue 2, so that the temperature of the molten metal in each runner is more uniform, and local overheating is avoided to a certain extent. At the same time, an annular riser 7 is set at the top of the cavity 1 to enhance the shrinkage compensation effect of the riser, so that the number of conformal sprues 8 can be reduced, and the exhaust of the cavity 1 is smoother.

[0024] The conformal sprue 8 is connected to the cavity 1 through the gap gate 9; a necking riser 10 is provided between the annular riser 7 and the conformal sprue 8. The cross section of the gap gate 9 is a trapezoidal structure, the width of the upper end is K=1.2~1.5δ, δ is the wall thickness of the cavity 1, the width of the cylinder centerline of the conformal sprue 8 at the lower end is D, and the height is H=0.5D+30mm.

[0025] Chills 11 are provided at the bottom and the outer side walls of the cavity 1. The thickness of the conformal chill 11 is 1.0 to 1.5 times the wall thickness of the quenching part, and the material thereof is cast aluminum, which is the same as the product material. The contact surface of the chill 11 with the cavity 1 is engraved with 1x1mm slag stripes, and the intervals of the slag stripes are 10x10mm to 20x20mm, and they are prismatic. The chill 11 mainly plays a quenching role, and effectively suppresses the tendency of pinholes and coarse grains to be easily generated due to overheating.

[0026] The cold iron 11 is respectively placed near the second-layer cylindrical ingates 6 and near the side wall of the cavity 1, and has different functions. The cold iron 11 near the second-layer cylindrical ingates 6 is mainly used to ensure that the product does not have defects such as looseness and shrinkage holes, while the cold iron 11 near the side wall of the cavity 1 is mainly used to ensure that the product does not have defects such as pinholes and coarse grains.

[0027] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the utility model. In this specification, the schematic representation of the terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0028] Based on the above ideal embodiments of the utility model, the relevant staff can make various changes and modifications without deviating from the technical concept of the utility model through the above description. The technical scope of the utility model is not limited to the content of the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. A pouring system for a bowl-shaped casting, comprising a mold cavity (1), a sprue (2) being arranged below the mold cavity (1), characterized in that: A first layer of runner (3) and a second layer of runner (4) are arranged in sequence from bottom to top between the sprue (2) and the cavity (1); the sprue (2) is connected to the first layer of runner (3); a first layer of cylindrical vertical runner (5) is arranged in communication between the first layer of runner (3) and the second layer of runner (4); a second layer of cylindrical endogate (6) connected to the cavity (1) is arranged on the second layer of runner (4); an annular riser (7) is arranged above the cavity (1); a conformal sprue (8) is arranged in communication between the second layer of runner (4) and the annular riser (7).

2. A pouring system for a bowl-shaped casting according to claim 1, characterized in that: The structure of the first-layer horizontal runner (3) is a cross-shaped structure; the structure of the second-layer horizontal runner (4) is a combined structure, with an outer ring of the structure being a ring and an inner cross-shaped structure; the number of the first-layer cylindrical vertical runners (5) is four, and they are arranged along the cross-shaped structure of the first-layer horizontal runner (3) and the second-layer horizontal runner (4).

3. A pouring system for a bowl-shaped casting according to claim 1, characterized in that: The cross-sectional area of ​​the first-layer horizontal runner (3) = (0.8-1.0) × the cross-sectional area of ​​the sprue (2); the cross-sectional area of ​​the first-layer cylindrical vertical runner (5) = the cross-sectional area of ​​the first-layer horizontal runner (3); the cross-sectional area of ​​the first-layer horizontal runner (3) = the cross-sectional area of ​​the second-layer horizontal runner (4); the diameter of the second-layer cylindrical ingate (6) = the diameter of the conformal sprue (8) = (4-6) × the average wall thickness of the cavity (1).

4. A pouring system for a bowl-shaped casting according to claim 1, characterized in that: The conformal sprue (8) is connected to the mold cavity (1) via a gap ingate (9); a necking riser (10) is provided between the annular riser (7) and the conformal sprue (8).

5. A pouring system for a bowl-shaped casting according to claim 1, characterized in that: Chilled iron (11) is provided on the bottom and the outer side wall of the cavity (1).

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