Sand mold structure for improving defects of nodular cast iron casting

Abstract

The utility model discloses a sand mold structure for improving defects of a nodular cast iron casting, which belongs to the technical field of casting and comprises a sand mold with a cavity. The shell has an air inlet and an air outlet; the sand core is arranged in the cavity and provided with a core head, and the end face of the core head abuts against the surface of the cavity and is provided with a first communicating port and a second communicating port; the first air channel, the third air channel and the fourth air channel are all located in the sand mold, and the air inlet communicates with the air outlet through the first air channel. The second air channel is located in the sand core and enables the first communication opening and the second communication opening to be communicated. The third air channel communicates the air inlet with the first communicating port; the fourth air channel communicates the air outlet with the second communication port; the gas inlet, the first gas channel and the gas outlet are sequentially communicated to form the cooling gas channel surrounding the cavity, the gas inlet, the third gas channel, the second gas channel, the fourth gas channel and the gas outlet are sequentially communicated to form the cooling gas channel extending into the sand core, gas is introduced into the cooling gas channel, and the solidification and cooling process of a casting can be accelerated.

Description

Technical Field

[0001] The utility model relates to the technical field of casting devices, in particular to a sand mold structure for improving defects of ductile iron castings. Background Art

[0002] The conventional sand mold structure usually consists of an upper sand mold, a lower sand mold, and a sand core; the lower sand mold is located at the bottom and placed in the assembly site; the sand core is located inside the lower sand mold, and the sand core is hoisted into the lower sand mold during assembly to complete the lower core; the upper sand mold is located above the lower sand mold, and a mold cavity is formed after assembly.

[0003] In the casting production process of this type of sand mold structure, the casting needs to solidify and form in the sand mold. The heat of the casting can only be dissipated through the heat exchange between the casting and the sand mold, and the heat dissipation rate is slow, especially the sand core located in the inner cavity of the casting. The sand core is wrapped by the casting except the core head. The sand core will receive heat from the casting around it, and the heat of the sand core can only be slowly released outward through the core head; this will cause the casting in the sand mold to cool down slowly, and the casting will be in a high temperature state for a long time. When the material of the casting is ductile iron, long-term high temperature may cause the internal structure of the casting to be coarse, which will reduce the performance of the casting and affect the service life of the casting.

[0004] Therefore, developing and designing a sand mold structure that can greatly accelerate the solidification and cooling process of the casting, avoid coarse casting structure, and improve the performance and service life of ductile iron castings is an urgent problem to be solved at this stage. Utility Model Content

[0005] In order to solve the problems existing in the prior art, the utility model provides a sand mold structure for improving the defects of ductile iron castings, wherein the air inlet, the first air duct and the air outlet are connected in sequence to form a cooling air duct arranged around the outside of the mold cavity, and the air inlet, the third air duct, the second air duct, the fourth air duct and the air outlet are connected in sequence to form a cooling air duct extending into the interior of the sand core. During the solidification and cooling process of the ductile iron casting, gas is introduced into the two cooling air ducts, and the gas exchanges heat with the sand mold and the sand core, which can greatly accelerate the solidification and cooling process of the ductile iron casting, avoid coarse casting structure, and improve the performance and service life of the ductile iron casting.

[0006] In order to achieve the above purpose, the technical solution adopted by the utility model is as follows:

[0007] The utility model provides a sand mold structure for improving defects of ductile iron castings, comprising:

[0008] A sand mold, wherein the sand mold has a mold cavity; and an air inlet and an air outlet are provided on an outer wall of the sand mold;

[0009] A sand core, the sand core is arranged in the mold cavity, the sand core has a core head, the core head abuts against the mold cavity surface; the lower end surface of the core head has a first communication port and a second communication port;

[0010] A first air channel, wherein the first air channel is located inside the sand mold and surrounds the mold cavity, and two ends of the first air channel are respectively connected to the air inlet and the air outlet;

[0011] a second air passage, the second air passage being located inside the sand core, and connecting the first communication port with the second communication port;

[0012] a third air channel, wherein the third air channel is located inside the sand mold, one end of the third air channel is connected to the air inlet, and the other end of the third air channel is connected to the first communication port;

[0013] A fourth air channel, wherein the fourth air channel is located inside the sand mold, one end of the fourth air channel is connected to the air outlet, and the other end of the fourth air channel is connected to the second connecting port.

[0014] As a preferred technical solution, the sand mold includes a lower sand mold and an upper sand mold arranged on the lower sand mold, and the mold cavity is formed when the upper sand mold and the lower sand mold are combined.

[0015] As a preferred technical solution, the air inlet, the air outlet, the first air channel, the third air channel and the fourth air channel are all located on the lower sand mold;

[0016] And / or, the air inlet and the air outlet are arranged opposite to each other, and the cavity is located between the air inlet and the air outlet;

[0017] And / or, the air inlet is connected to an air source via a pipeline.

[0018] As a preferred technical solution, part of the first air channel is arranged in a spiral shape around the cavity.

[0019] As a preferred technical solution, a core seat matching the core head is provided at the bottom of the cavity, and the core head is embedded in the core seat.

[0020] As a preferred technical solution, an oil rope is laid between the end surface of the core head and the cavity surface.

[0021] As a preferred technical solution, the oil rope divides the abutment surface between the end surface of the core head and the cavity surface into a plurality of mutually isolated areas, and the first connecting port and the second connecting port are respectively located in different areas.

[0022] As a preferred technical solution, at least a portion of the second air channel is spiral and is disposed close to the outer surface of the sand core.

[0023] As a preferred technical solution, the second airway includes a main airway and multiple sub-airways, one end of the main airway is connected to the first connecting port, one end of the multiple sub-airways are connected to the other end of the main airway and are radially distributed, and the other end of the multiple sub-airways are connected to the second connecting port.

[0024] As a preferred technical solution, the main air channel extends to an end of the sand core away from the core head;

[0025] And / or, the second communication port corresponds one-to-one with the sub-airway.

[0026] The beneficial effects of the utility model are as follows:

[0027] The utility model discloses an air inlet, a first air duct and an air outlet which are connected in sequence to form a cooling air duct which is arranged around the outside of the cavity; the air inlet, a third air duct, a second air duct, a fourth air duct and the air outlet are connected in sequence to form a cooling air duct which extends into the interior of the sand core; during the solidification and cooling process of the ductile iron casting, gas is introduced into the two cooling air ducts, and the gas exchanges heat with the sand mold and the sand core, which can greatly accelerate the solidification and cooling process of the ductile iron casting, avoid coarse casting structure, reduce the use of cold iron in the casting process and the grinding work of the subsequent casting, save a lot of working hours, reduce the casting cost, and improve the performance and service life of the ductile iron casting. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a schematic diagram of the overall structure of a first embodiment of a sand mold structure for improving defects of ductile iron castings according to the utility model;

[0029] Figure 2 It is a schematic diagram of the overall structure of a second embodiment of a sand mold structure for improving defects of ductile iron castings according to the utility model;

[0030] Figure 3 for Figure 2 A top view of the second airway along direction A.

[0031] In the figure: 1-sand mold, 11-mold cavity, 12-air inlet, 13-air outlet, 14-lower sand mold, 15-upper sand mold, 16-core seat, 2-sand core, 21-core head, 22-first connecting port, 23-second connecting port, 3-first air channel, 4-second air channel, 41-main air channel, 42-sub-air channel, 5-third air channel, 6-fourth air channel. DETAILED DESCRIPTION

[0032] In order to facilitate understanding by those skilled in the art, the present invention is further described below in conjunction with the accompanying drawings.

[0033] Embodiment 1

[0034] Please refer to Figure 1 , which is an embodiment of a sand mold structure for improving defects of ductile iron castings provided by the utility model, comprising a sand mold 1, wherein the sand mold 1 has a mold cavity 11, a sand core 2 is arranged in the mold cavity 11, the sand core 2 has a core head 21, the core head 21 is against the surface of the mold cavity 11, and the sand core 2 and the mold cavity 11 surface together form the shape of the ductile iron casting; an air inlet 12 and an air outlet 13 are arranged on the outer wall surface of the sand mold 1; a first air duct 3 is located inside the sand mold 1 and is arranged around the mold cavity 11, and the two ends of the first air duct 3 are respectively connected to the air inlet 12 and the air outlet 13 to form a cooling air duct arranged outside the mold cavity 11; a first connecting port 22 and a second connecting port 23 are arranged on the lower end surface of the core head 21, and a second air duct 4 is located inside the sand core 2, and the second air duct 4 connects the first connecting port 2 2 is connected with the second connecting port 23, one end of the third air channel 5 located inside the sand mold 1 is connected with the air inlet 12, and the other end is connected with the first connecting port 22; one end of the fourth air channel 6 located inside the sand mold 1 is connected with the air outlet 13, and the other end is connected with the second connecting port 23, the air inlet 12, the third air channel 5, the second air channel 4, the fourth air channel 6 and the air outlet 13 are connected in sequence to form a cooling air channel extending into the sand core 2; during the solidification and cooling process of the ductile iron casting, gas is introduced into the two cooling air channels, and the gas exchanges heat with the sand mold 1 and the sand core 2, which can greatly accelerate the solidification and cooling process of the ductile iron casting. At the same time, the cooling air channel can also accelerate the discharge of the high-temperature gas inside the sand mold 1, and further realize the rapid cooling of the ductile iron casting.

[0035] For details, please refer to Figure 1 The bottom of the cavity 11 is provided with a core seat 16 matching the core head 21. The core head 21 is embedded in the core seat 16 when the core is lowered, which can effectively position the core head 21 and ensure that the end face of the core head 21 is in close contact with the surface of the cavity 11.

[0036] Furthermore, an oil rope should be laid between the end face of the core head 21 and the surface of the cavity 11. The oil rope can prevent high-temperature molten iron from entering the cooling air channel, causing the molten iron to leak out and cause fire, thereby avoiding safety problems; further, the oil rope separates the abutting surface between the end face of the core head 21 and the surface of the cavity 11 into a plurality of mutually isolated areas, and the first connecting port 22 and the second connecting port 23 are respectively located in different areas. The oil rope isolates the first connecting port 22 and the second connecting port 23 to ensure that the gas in the third air channel 5 must enter the second air channel 4 and then be discharged from the fourth air channel 6, thereby avoiding the third air channel 5 from being directly connected to the fourth air channel 6; specifically, the plurality of areas separated by the oil rope are preferably fan-shaped, matching the end face shape of the core head 21.

[0037] In this embodiment, please refer to Figure 1 The sand mold 1 includes a lower sand mold 14 and an upper sand mold 15 arranged on the lower sand mold 14. The upper sand mold 15 forms a mold cavity 11 when the lower sand mold 14 is combined; the air inlet 12, the air outlet 13, the first air duct 3, the third air duct 5 and the fourth air duct 6 are all located on the lower sand mold 14. Since the air ducts need to be placed during the molding process, they are all arranged on the lower sand mold 14 to facilitate production and use; in other embodiments, the air inlet 12 and the air outlet 13 can also be arranged on the upper sand mold 15, and the first air duct 3 can also be arranged in the upper sand mold 15 and the lower sand mold 14 at the same time, so as to ensure that the first air duct 3 can be arranged around the mold cavity 11 to effectively realize heat exchange and cooling.

[0038] For further information, please refer to Figure 1 The air inlet 12 and the air outlet 13 are preferably arranged relative to each other, and the cavity 11 is located between the air inlet 12 and the air outlet 13. The gas enters from the air inlet 12 and is discharged from the air outlet 13 after heat exchange. In other embodiments, the air inlet 12 and the air outlet 13 may also be located on the same side, based on the fact that the cooling air ducts in the sand mold 1 and the sand core 2 can effectively achieve heat exchange and cooling.

[0039] It should be noted that the air inlet 12 should be connected to an air source through a pipeline, and the air source can continuously deliver gas to the air inlet 12; specifically, the air source can be an air blower or an air pump.

[0040] In this embodiment, please refer to Figure 1 The air inlet 12 is located at the lower end of the lower sand mold 14, the first air channel 3 first extends vertically upward to the upper end of the sand mold 1 and then spirally surrounds the cavity 11 downward. The spiral part of the first air channel 3 should be arranged close to the cavity 11 to form an external spiral heat exchange structure, which can effectively improve the heat exchange and cooling effect; in other embodiments, the first air channel 3 can also be of other shapes and be arranged close to the cavity 11, so as to be able to effectively exchange heat with the sand mold 1.

[0041] Based on the above examples, please refer to Figure 1 The second air channel 4 first extends vertically upward to the upper end of the sand core 2 and then extends spirally downward. The spiral portion of the second air channel 4 should be arranged close to the outer peripheral surface of the sand core 2 to form an inner spiral heat exchange structure, which can effectively improve the heat exchange and cooling effect.

[0042] Please refer to Figure 1 , the specific working mode of the utility model is as follows:

[0043] After pouring is completed, under the premise of ensuring that there is no safety risk, the air inlet 12 is connected to the air source through a pipeline, and the gas enters the sand mold 1 and the sand core 2 respectively along the two cooling air passages. The gas is discharged from the sand mold 1 from the air outlet 13 after heat exchange with the sand mold 1 or the sand core 2. By continuously blowing air into the cooling air passage, the cooling inside the sand mold 1 can be greatly accelerated, and the heat exchange efficiency between the ductile iron casting and the sand mold 1 and the sand core 2 can be improved, so that the ductile iron casting can be cooled quickly, and the purpose of refining the casting structure and improving the casting performance can be achieved.

[0044] Embodiment 2

[0045] Please refer to Figure 2 and Figure 3 The main difference between this embodiment and the first embodiment is that the second air channel 4 includes a main air channel 41 and multiple sub-air channels 42, one end of the main air channel 41 is connected to the first connecting port 22, one end of the multiple sub-air channels 42 are connected to the other end of the main air channel 41 and are radially distributed, and the other ends of the multiple sub-air channels 42 are connected to the second connecting port 23, which can also effectively exchange heat with the sand core 2.

[0046] In this embodiment, please refer to Figure 2 and Figure 3 The main air channel 41 extends from bottom to top to the upper end of the sand core 2, and multiple sub-air channels 42 extend radially downward from the upper end of the sand core 2 and are arranged close to the cavity 11, which can effectively improve the heat exchange and cooling effect.

[0047] For further information, please refer to Figure 2 and Figure 3 , the second connecting port 23 is set to be multiple, and the second connecting port 23 corresponds to the sub-gas channel 42 one by one. Correspondingly, one end of the fourth gas channel 6 should also be provided with multiple connecting ports that correspond to and are connected to the second connecting port 23 one by one, to ensure that the gas in the sub-gas channel 42 can be discharged along the fourth gas channel 6; in other embodiments, the second connecting port 23 can also be set to one, in this case, multiple sub-gas channels 42 are connected to the second connecting port 23; or, the first connecting port 22 can also be set to be multiple, in this case, the main gas channel 41 is set to be multiple and respectively connected to the first connecting port 22; so as to effectively realize the heat exchange with the sand core 2.

[0048] The above description is only the preferred embodiment of the utility model, and is not intended to limit the utility model. For those skilled in the art, the utility model can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the utility model shall be included in the protection scope of the utility model.

Claims

1. A sand mold structure for improving defects of ductile iron castings, characterized in that: include: A sand mold (1), wherein the sand mold (1) has a mold cavity (11); and an air inlet (12) and an air outlet (13) are provided on an outer wall surface of the sand mold (1); A sand core (2), the sand core (2) being arranged in the mold cavity (11), the sand core (2) having a core head (21), the core head (21) being against the surface of the mold cavity (11); a first communication opening (22) and a second communication opening (23) being provided on the lower end surface of the core head (21); A first air channel (3), the first air channel (3) being located inside the sand mold (1) and surrounding the mold cavity (11), and the two ends of the first air channel (3) being respectively connected to the air inlet (12) and the air outlet (13); a second air passage (4), the second air passage (4) being located inside the sand core (2), the second air passage (4) connecting the first communication port (22) and the second communication port (23); a third air channel (5), the third air channel (5) being located inside the sand mold (1), one end of the third air channel (5) being connected to the air inlet (12), and the other end of the third air channel (5) being connected to the first communication port (22); A fourth air channel (6), wherein the fourth air channel (6) is located inside the sand mold (1), one end of the fourth air channel (6) is connected to the air outlet (13), and the other end of the fourth air channel (6) is connected to the second connecting port (23).

2. A sand mold structure for improving defects of ductile iron castings according to claim 1, characterized in that: The sand mold (1) comprises a lower sand mold (14) and an upper sand mold (15) arranged on the lower sand mold (14); when the upper sand mold (15) and the lower sand mold (14) are combined, the mold cavity (11) is formed.

3. A sand mold structure for improving defects of ductile iron castings according to claim 2, characterized in that: The air inlet (12), the air outlet (13), the first air channel (3), the third air channel (5) and the fourth air channel (6) are all located on the lower sand mold (14); And / or, the air inlet (12) and the air outlet (13) are arranged opposite to each other, and the cavity (11) is located between the air inlet (12) and the air outlet (13); And / or, the air inlet (12) is connected to an air source via a pipeline.

4. A sand mold structure for improving defects of ductile iron castings according to claim 2, characterized in that: Part of the first air channel (3) is arranged in a spiral shape around the cavity (11).

5. A sand mold structure for improving defects of ductile iron castings according to claim 2, characterized in that: A core seat (16) matching the core head (21) is provided at the bottom of the mold cavity (11), and the core head (21) is embedded in the core seat (16).

6. A sand mold structure for improving defects of ductile iron castings according to claim 1, characterized in that: An oil rope is laid between the end surface of the core head (21) and the surface of the cavity (11).

7. A sand mold structure for improving defects of ductile iron castings according to claim 6, characterized in that: The oil rope divides the contact surface between the end surface of the core head (21) and the surface of the cavity (11) into a plurality of mutually isolated areas, and the first communication port (22) and the second communication port (23) are respectively located in different areas.

8. A sand mold structure for improving defects of ductile iron castings according to claim 1 or 7, characterized in that: At least part of the second air channel (4) is spiral-shaped and is arranged close to the outer surface of the sand core (2).

9. A sand mold structure for improving defects of ductile iron castings according to claim 1 or 7, characterized in that: The second air channel (4) comprises a main air channel (41) and a plurality of sub-air channels (42), one end of the main air channel (41) is connected to the first connecting port (22), one end of the plurality of sub-air channels (42) are connected to the other end of the main air channel (41) and are radially distributed, and the other ends of the plurality of sub-air channels (42) are connected to the second connecting port (23).

10. A sand mold structure for improving defects of ductile iron castings according to claim 9, characterized in that: The main air channel (41) extends to an end of the sand core (2) away from the core head (21); And / or, the second communication port (23) corresponds one-to-one with the sub-airway (42).

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