Casting mold with built-in blind risers

Abstract

The utility model provides a casting mold with built-in blind risers. The casting mold with the built-in blind riser comprises a molding box, a sand core is arranged in the molding box, a cavity of a casting is formed between the sand core and the inner space of the molding box, the blind riser is arranged above the cavity, the side portion of the blind riser is provided with an integrated inner pouring gate, the liquid outlet end of the inner pouring gate is located at the top of the cavity, the size of the inner pouring gate is gradually reduced from the liquid inlet end to the liquid outlet end, and the inner pouring gate is in a prismatic table shape. The casting process of the built-in blind riser is adopted, and the blind riser and the ingate are integrated, so that the feeding effect is more direct and effective; and a similar horn-shaped flow gate is adopted, and a tooth shape is avoided, so that the liquidity of molten iron is improved, and sand cleaning is more convenient and labor-saving.

Description

Technical Field

[0001] The utility model relates to the technical field of casting moulds, in particular to a casting mould with a built-in hidden riser. Background Art

[0002] Traditionally, when preparing large-volume vacuum pump rotor castings, the process scheme of open riser is adopted, but it cannot achieve a good iron shrinkage compensation effect, and the product is prone to casting defects such as shrinkage and shrinkage. In addition, since the vacuum pump rotor casting has a tooth shape, if the gate is located at the tooth shape during the casting process, it affects the fluidity of the molten iron, increases the difficulty of subsequent sand cleaning, and the existence of the tooth shape also makes it difficult to remove the mold. Utility Model Content

[0003] Based on this, it is necessary to provide a casting mold with a built-in blind riser to address the problem that the existing process for preparing large-volume vacuum pump rotor castings is prone to casting defects such as shrinkage and shrinkage holes.

[0004] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0005] A casting mold with a built-in blind riser comprises a mold box, a sand core is built in the mold box, a mold cavity of a casting is formed between the sand core and the internal space of the mold box, a blind riser is provided above the mold cavity, an integrated ingates are provided on the side of the blind riser, a liquid outlet end of the ingates is located at the top of the mold cavity, and the size of the ingates gradually decreases from the liquid inlet end to the liquid outlet end, forming a prism shape.

[0006] Furthermore, the sand core includes an inner core and an outer core; the outer core is located at the outer periphery of the inner core, and the gap between the inner core and the outer core and the mold box together form the mold cavity of the casting; the outer core is composed of two sub-cores, which are spliced ​​into one with concave and convex fit.

[0007] Furthermore, one of the sub-core end faces of the outer core is symmetrically provided with protrusions, the width of the protrusions gradually decreases along the radial direction, and the end face of the other sub-core is correspondingly provided with a groove adapted to the protrusion. When the two sub-core end faces are fitted together, the protrusions are all located in the grooves.

[0008] Furthermore, one of the sub-core end faces of the outer core is provided with a protrusion in an offset manner, and the width of the protrusion gradually decreases along the radial direction. A corresponding groove matching the protrusion is provided on the end face of the other sub-core. When the two sub-core end faces are fitted together, all the protrusions are located in the groove.

[0009] Furthermore, the mold box is provided with a horizontal runner and a vertical runner; the blind riser is located in the horizontal runner, one end of the horizontal runner is connected to the vertical runner, and the vertical runner is arranged longitudinally and the top end is flush with the top of the mold box.

[0010] Furthermore, a filter sheet is provided at the connection point between the runner and the sprue.

[0011] Furthermore, the top of the inner core has a flat-mouthed air outlet, which is narrow at the bottom and wide at the top.

[0012] Furthermore, the height of the liquid inlet end of the ingrowth is smaller than the width, and the height of the liquid inlet end is consistent with the width of the liquid outlet end.

[0013] Furthermore, the inner core is in the shape of a vacuum pump rotor, the outer core is in the shape of a sleeve, and the liquid outlet end of the inner pouring channel is located at the top of the toothed portion of the inner core.

[0014] Compared with the prior art, the beneficial effects of the utility model include:

[0015] 1. The utility model adopts a casting process with a built-in blind riser. The blind riser is integrated with the ingates, and the shrinkage compensation effect is more direct and effective. It also adopts a trumpet-shaped ingates and avoids the tooth shape, which increases the fluidity of the molten iron and makes sand cleaning more convenient and labor-saving.

[0016] 2. The utility model adopts a double split core structure design at the tooth shape to avoid difficult demoulding. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The disclosure of the present invention is described with reference to the accompanying drawings. It should be understood that the drawings are only for illustrative purposes and are not intended to limit the scope of protection of the present invention. In the drawings, the same reference numerals are used to refer to the same components. Among them:

[0018] Figure 1 A top view of a casting mold with a built-in hidden riser introduced in the utility model is obtained;

[0019] Figure 2 Based on Figure 1 A three-dimensional image of a dark riser;

[0020] Figure 3 Based on Figure 1 Schematic diagram of the double split core of the outer core.

[0021] Explanations in the figure: 1. Mold box; 2. Sand core; 21. Inner core; 22. Outer core; 3. Blind riser; 4. Inner runner; 5. Horizontal runner; 6. Vertical runner; 7. Air outlet. DETAILED DESCRIPTION

[0022] It is easy to understand that according to the technical solution of the utility model, without changing the essential spirit of the utility model, a person skilled in the art can propose a variety of interchangeable structural modes and implementation modes. Therefore, the following specific implementation modes and drawings are only exemplary descriptions of the technical solution of the utility model, and should not be regarded as the entirety of the utility model or as a limitation or restriction to the technical solution of the utility model.

[0023] Example 1

[0024] See also Figure 1 This embodiment introduces a casting mold with a built-in blind riser, which is mainly composed of a mold box 1, a sand core 2, a blind riser 3, an inner runner 4, a horizontal runner 5, a straight runner 6, etc. The sand core 2 is located in the mold box 1, and the sand core 2 includes an outer core 22 and an inner core 21. Since this embodiment takes the preparation of a large-air-exhaust vacuum pump rotor casting as an example, the cavity gap between the inner core 21 and the outer core 22 constitutes the cavity of the large-air-exhaust vacuum pump rotor, that is, the cavity of the casting. Since the sand core 2 is located in the mold box 1, except for the cavity of the casting, the remaining gaps between the sand core 2 and the mold box 1 can be filled with resin sand or the like.

[0025] Due to the external shape of the rotor of the vacuum pump with large air extraction capacity, the inner core 21 is axial at both ends and has a tooth shape in the middle. The outer core 22 is cylindrical and is placed on the outer periphery of the inner core 21. In order to reduce the difficulty of demoulding, the outer core 22 is composed of two sub-cores, that is, the two sub-cores are spliced ​​together to form the outer core 22. The two sub-cores have the same shape and are semi-circular. Figure 3 As shown, in order to facilitate the splicing of two split cores, one of the split cores is symmetrically provided with a protrusion on its end face, and the protrusion gradually decreases in radial width, and the other split core is correspondingly provided with a groove adapted to the protrusion. When the two split core end faces are fitted, the protrusions are all located in the groove, and the two split cores are spliced ​​into a complete inner core 21. In order to facilitate the discharge of air inside the casting cavity, the top of the inner core 21 has a flat-mouthed air outlet 7, which is narrow at the bottom and wide at the top, so as to facilitate the upward discharge of air.

[0026] like Figure 2 As shown, the top of the inner core 21 with the toothed portion overlaps the liquid outlet end of the ingrow 4, the ingrow 4 is connected with the blind riser 3 as a whole, the blind riser 3 is located on the cross runner 5 and connected, one end of the cross runner 5 is connected with the straight runner 6, the straight runner 6 is arranged longitudinally and the top is flush with the top of the mold box 1, so the casting process is that the molten iron is injected into the straight runner 6, then enters the blind riser 3 along the cross runner 5, and finally enters the mold cavity through the ingrow 4. In order to facilitate the ingrow 4 to guide the molten iron into the mold cavity, the port size of the ingrow 4 gradually decreases from the liquid inlet end to the liquid outlet end, and the overall shape is a prism. That is, the size of one end of the ingrow 4 connected to the blind riser 3 is larger than the size of the other end. In addition, the height of the liquid inlet end of the ingrow 4 can be limited to be less than the width, and the height of the liquid inlet end is consistent with the width of the liquid outlet end, so that the size of the ingrow is within a suitable range. In order to reduce the entry of impurities into the mold cavity, a filter is provided at the connection between the cross runner 5 and the straight runner 6.

[0027] This embodiment adopts a casting process with a built-in blind riser. The blind riser is integrated with the ingates, and the shrinkage compensation effect is more direct and effective. A trumpet-shaped ingates is adopted, and the tooth shape is avoided, which increases the fluidity of the molten iron and makes sand cleaning more convenient and labor-saving. A double-split core structure design is adopted at the tooth shape to avoid the difficult demoulding.

[0028] Example 2

[0029] This embodiment introduces a casting mold with a built-in blind riser, which is basically the same as the casting mold with a built-in blind riser described in Example 1. The difference is that one of the split core end faces of the outer core 22 of this embodiment is provided with a protrusion in a staggered manner, and the protrusion gradually decreases in radial width, and the end face of the other split core is provided with a groove adapted to the protrusion, and when the two split core end faces are fitted, the protrusions are all located in the grooves. Although the staggered setting increases the difficulty of splicing, it can reduce the number of protrusions and grooves.

[0030] This embodiment has the same beneficial effects as Embodiment 1.

[0031] The technical scope of the present invention is not limited to the contents described above. Those skilled in the art can make various deformations and modifications to the above embodiments without departing from the technical concept of the present invention, and these deformations and modifications should all fall within the protection scope of the present invention.

Claims

1. A casting mold with a built-in blind riser (3), characterized in that: The mold box (1) comprises a mold box (1) having a sand core (2) therein, a mold cavity of a casting formed between the sand core (2) and the internal space of the mold box (1), a blind riser (3) being provided above the mold cavity, an integral ingates (4) being provided on the side of the blind riser (3), a liquid outlet end of the ingates (4) being located at the top of the mold cavity, and a size of the ingates (4) gradually decreasing from the liquid inlet end to the liquid outlet end, forming a prism shape; The sand core (2) comprises an inner core (21) and an outer core (22); the outer core (22) is located on the outer periphery of the inner core (21); the gap between the inner core (21) and the outer core (22) together with the mold box (1) form a mold cavity of the casting; the outer core (22) is composed of two sub-cores, which are spliced ​​into one body with concave and convex fittings; the top of the inner core (21) has a flat-mouthed air outlet (7), and the air outlet (7) is narrow at the bottom and wide at the top.

2. The casting mold with built-in blind riser (3) according to claim 1, characterized in that: One of the split core end faces of the outer core (22) is symmetrically provided with a protrusion, the width of the protrusion gradually decreases along the radial direction, and the end face of the other split core is correspondingly provided with a groove adapted to the protrusion, and when the two split core end faces are fitted together, the protrusion is completely located in the groove.

3. The casting mold with built-in blind riser (3) according to claim 1, characterized in that: One of the split core end faces of the outer core (22) is provided with a protrusion in an offset manner, the protrusion gradually reducing in width along the radial direction, and the other split core end face is provided with a corresponding groove adapted to the protrusion, and when the two split core end faces are fitted together, the protrusion is completely located in the groove.

4. The casting mold with built-in blind riser (3) according to claim 1, characterized in that: The mold box (1) has a runner (5) and a sprue (6); the blind riser (3) is located in the runner (5) and is connected to the runner; one end of the runner (5) is connected to the sprue (6); the sprue (6) is arranged longitudinally and the top end is flush with the top of the mold box (1).

5. The casting mold with built-in blind riser (3) according to claim 4, characterized in that: A filter sheet is provided at the connection point between the horizontal runner (5) and the straight runner (6).

6. The casting mold with built-in blind riser (3) according to claim 1, characterized in that: The height of the liquid inlet end of the ingrowth (4) is smaller than its width, and the height of the liquid inlet end is consistent with the width of the liquid outlet end.

7. The casting mold with built-in blind riser (3) according to claim 1, characterized in that: The inner core (21) is in the shape of a vacuum pump rotor, the outer core (22) is in the shape of a sleeve, and the liquid outlet end of the inner pouring channel (4) is located at the top of the toothed portion of the inner core (21).

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