Casting device and casting method for vertical double layers of shaft castings

Abstract

The invention discloses a vertical double-layer casting device for shaft castings. The vertical double-layer casting device is composed of two identical iron molds (1) in a mold closing mode. A plurality of shaping grooves (2) are formed in the iron mold (1), a straight runner groove (3) is formed in the middle of the iron mold (1), and transverse runner grooves (4) communicated with the shaping grooves (2) are formed in the two sides of the straight runner groove (3); a film coating layer (5) is paved in the shaping groove (2), the straight runner groove (3) and the transverse runner groove (4); and a double-sided sand core (6) is arranged between the film coating layers (5) of the two iron molds (1), and the film coating layers (5) on the two sides and the double-sided sand core (6) form two casting mold cavities (7). Molten iron mold filling can be stable, the quality of shaft castings is greatly improved, the production efficiency is effectively improved, and the whole operation process is simple and convenient. In addition, the same iron mold is adopted for die assembly casting, so that the model investment is reduced, and the cost is reduced.

Description

Technical Field

[0001] The invention relates to the field of shaft casting, in particular to a vertical double-layer casting device and a casting method for shaft castings. Background Art

[0002] Iron mold sand-coated casting is a casting method that covers the inner cavity of a metal mold with a thin layer of sand to form a high-strength cavity. This process is easy to realize automated production and has the characteristics of energy saving, financial saving, high quality, and environmental protection. In traditional iron mold sand-coated casting production, castings are generally placed horizontally. For shaft castings, the molten iron filling distance is long, the molten iron filling is not stable, and casting defects such as oxidized slag are easily generated. In addition, a single-layer cavity is set in the traditional iron mold sand-coated casting process, resulting in a small number of molded shafts and low production efficiency. Traditional iron mold sand-coated casting production requires an upper iron mold, a lower iron mold, and a matching upper mold plate device and a lower mold plate device, which has a high investment cost. Summary of the invention

[0003] The purpose of the present invention is to provide a casting device and method for vertical double-layer shaft castings. The present invention can make the molten iron filling the mold stable, greatly improve the quality of shaft castings, and effectively improve the production efficiency. The overall operation process is simple and convenient. In addition, the present invention uses the same iron mold for mold casting, which reduces the model investment and reduces the cost.

[0004] The technical solution of the present invention is as follows: a vertical double-layer casting device for shaft castings, which is composed of two identical iron molds, wherein the iron mold has a plurality of molding grooves, the middle part of the iron mold has a straight runner groove, and both sides of the straight runner groove have transverse runner grooves connected to the molding grooves; the molding grooves, the straight runner grooves and the transverse runner grooves are paved with coating layers; a double-sided sand core is provided between the coating layers of the two iron molds, and the coating layers on both sides and the double-sided sand core form two casting cavities; a pouring gate, a straight runner, a transverse runner and a transverse runner cavity are provided between the coating layers, and the pouring gate, the straight runner, the transverse runner and the transverse runner cavity are connected in sequence, and the transverse runner cavity is connected to the casting cavity.

[0005] In the above-mentioned vertical double-layer casting device for shaft castings, the pouring port is in a trumpet shape with a large outside and a small inside.

[0006] In the aforementioned vertical double-layer casting device for shaft castings, the inner side of the iron mold corresponding to one end of the casting cavity is provided with an exhaust groove, and the exhaust layers on the two sides of the iron mold are combined to form the exhaust groove.

[0007] In the aforementioned vertical double-layer casting device for shaft castings, the depth of the exhaust sub-grooves ranges from 0.14 to 0.16 mm, and the depth of the exhaust grooves ranges from 0.28 to 0.32 mm.

[0008] In the aforementioned vertical double-layer casting device for shaft castings, positioning pins and positioning pin sleeves are respectively provided on the inner diagonals of the iron mold, and the iron molds on both sides are connected through the cooperation of the positioning pins and the positioning pin sleeves.

[0009] In the aforementioned vertical double-layer casting device for shaft castings, positioning holes are provided on the four inner corners of the iron mold, and the positioning pins and positioning pin sleeves are arranged diagonally in the positioning holes.

[0010] In the aforementioned vertical double-layer casting device for shaft castings, the positioning pin includes a pin base fixed in a positioning hole, and the pin base has a cylindrical pin body; the positioning pin sleeve includes a sleeve body, and the sleeve body has an elliptical hole matching the cylindrical pin body.

[0011] The casting method of the vertical double-layer casting device for shaft castings mentioned above has the following specific steps:

[0012] Step 1: Cover the groove surface of the molding groove, the straight runner groove and the transverse runner groove of the iron mold with a coating layer, and put a double-sided sand core between the iron molds on both sides. The coating layer and the double-sided sand core form a double-layer casting cavity, and the casting channel is also formed at this time;

[0013] Step 2, pour molten iron toward the pouring gate, the molten iron flows into the upper and lower runners through the sprue, and then flows through each runner cavity and the inner gate from the runner to the left and right casting cavities. The molten iron fills the casting cavity from bottom to top, and the gas is discharged from the exhaust groove at the same time. Wait for the molten iron to cool down, and the shaft casting is formed.

[0014] In the aforementioned vertical double-layer casting method for shaft castings, in step 1, when the groove surfaces of the molding groove, the straight runner groove and the transverse runner groove of the iron mold are covered with a coating layer, the iron mold is placed on the mold plate bracket of the model device, and the model device is equipped with an electric heating pipe to heat the model. After the iron mold and the model are molded together, a gap of a sand-covered layer is formed between them; a cylinder is installed on the mold plate bracket to press a pressing plate on the side of the model and the iron mold, and the pressing plate presses the gap between the iron mold and the model to prevent sand from running out from the side when shooting sand. Use professional equipment to blow the coated sand from the sand shooting hole of the iron mold into the gap between the iron mold and the model, and the coated sand solidifies and sticks to the iron mold when heated.

[0015] In the aforementioned vertical double-layer casting method for shaft castings, in step 2, the casting cavity is double-layered, and there is sufficient molten iron when injecting molten iron from the pouring port, which will generate sufficient heat to raise the temperature of the iron mold to 200-230°C, facilitating the next sand covering molding and eliminating the iron mold heating step.

[0016] Compared with the prior art, the present invention has the following advantages:

[0017] 1. In the present invention, a coating layer is coated on the groove surface of the shaping groove, the straight runner groove and the transverse runner groove of the iron mold, and a double-sided sand core is placed between the iron molds on both sides. The coating layer and the double-sided sand core form a double-layer casting cavity, and the casting channel is also formed at this time; molten iron is poured toward the pouring port, and the molten iron flows into the upper and lower layers of the transverse runners respectively through the straight runner, and then flows into the double-layer casting cavity through the transverse runner through each transverse runner cavity and the inner gate, and the molten iron fills the casting cavity from bottom to top. Through this structural form, the molten iron can fill the mold smoothly, which greatly improves the quality of shaft castings, and by setting a double-layer casting cavity, double the number of shaft castings can be obtained, which effectively improves production efficiency, and the entire casting process is simple and convenient.

[0018] 2. There are exhaust grooves on the inner side of the iron mold corresponding to one end of the casting cavity, and the exhaust grooves on both sides of the iron mold are combined to form an exhaust groove; during the pouring process, the molten iron flows from bottom to top, and the gas is concentrated at the upper end of the casting cavity. The gas is discharged from the exhaust groove, reducing the occurrence of air holding phenomenon, so that the casting will not have defects such as insufficient pouring or pores.

[0019] 3. In order to prevent the two pieces of iron from having different temperatures and inconsistent sizes after thermal expansion, the locating pin and the locating pin sleeve can still fit tightly. Therefore, a cylindrical locating pin and an elliptical locating pin sleeve are used to match.

[0020] 4. The iron mold is simultaneously equipped with positioning pins and positioning pin sleeves, which are arranged at two diagonal corners respectively, so that two identical iron molds can fit together, thereby improving the accuracy of the matching of the two iron molds; since the two iron molds have the same structure, only one model device is needed for the two iron molds, thus saving the investment in the model device and facilitating the manufacturing and production management of the iron molds. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a structural schematic diagram of the present invention;

[0022] Figure 2 is a schematic diagram of the shaping groove;

[0023] Figure 3 is a schematic diagram of the casting cavity;

[0024] Figure 4 is a schematic diagram of a positioning pin sleeve;

[0025] Figure 5 is a schematic diagram of a positioning pin;

[0026] Figure 6 Schematic diagram of the cylinder.

[0027] Explanation of the marks in the accompanying drawings: 1-iron mold, 2-molding groove, 3-sprue groove, 4-lateral runner groove, 5-coating layer, 6-double-sided sand core, 7-casting cavity, 8-pouring gate, 9-sprue, 10-lateral runner, 11-lateral runner cavity, 12-exhaust groove, 13-exhaust groove, 14-locating pin, 15-locating pin sleeve, 16-locating hole, 17-int gate, 18-model, 19-electric heating tube, 20-mold plate bracket, 21-cylinder, 22-pressure plate, 23-sand shooting hole, 141-pin base, 142-cylindrical pin body, 151-sleeve body, 152-elliptical hole. DETAILED DESCRIPTION

[0028] The present invention will be further described below in conjunction with the accompanying drawings and embodiments, but they are not intended to limit the present invention.

[0029] Embodiment: A vertical double-layer casting device for shaft castings, comprising two identical iron molds 1, as shown in the attached Figure 1 As shown, the iron mold 1 has a plurality of shaping grooves 2, as shown in the attached Figure 2 As shown, the middle part of the iron mold 1 has a straight runner groove 3, and both sides of the straight runner groove 3 have transverse runner grooves 4 connected to the shaping groove 2; the shaping groove 2, the straight runner groove 3 and the transverse runner groove 4 are paved with a coating layer 5, and the coating layer is mainly composed of coated sand, and the coated sand can be coated on the groove wall by heating; there is a double-sided sand core 6 between the coating layers 5 of the two iron molds 1, and the coating layers 5 on both sides and the double-sided sand core 6 form two casting cavities 7, as shown in the attached Figure 3 As shown; a pouring gate 8, a sprue 9, a runner 10 and a runner cavity 11 are arranged between the coating layers 5, the pouring gate 8, the sprue 9, the runner 10 and the runner cavity 11 are connected in sequence, the runner cavity 11 is connected to the casting cavity 7, the inner side of the iron mold is covered with a coating layer, and the coating layers on both sides are pieced together to form a complete pouring channel, the coating layer is in full contact with the iron mold, and the heat absorption effect of the iron mold is fully utilized to improve the quality of the casting. The pouring gate 8 is a trumpet shape with a large outside and a small inside, which is convenient for pouring molten iron. The molten iron will enter the runner on the lower side along the sprue, flow into the runner cavity, and then enter the inner gate 17 connected to the end of the casting cavity, and the molten iron will fill the casting cavity from bottom to top.

[0030] The inner side of the iron mold 1 corresponds to one end of the casting cavity 7 and has a venting groove 12. The venting grooves 12 on the two sides of the iron mold 1 are combined to form a venting groove 13. The depth of the venting groove 12 is between 0.14 and 0.16 mm, and the depth of the venting groove 13 is between 0.28 and 0.32 mm. During the pouring process, the molten iron flows from bottom to top, and the gas is concentrated at the upper end of the casting cavity. The gas is discharged from the venting groove, which reduces the occurrence of air holding phenomenon and prevents the casting from having defects such as insufficient pouring or pores. The depth of the venting groove is generally selected to be 0.15 mm, and the depth of the venting groove is generally selected to be 0.3 mm.

[0031] The iron mold 1 is provided with positioning pins 14 and positioning pin sleeves 15 on the inner diagonals, and the iron molds 1 on both sides are connected by the cooperation of the positioning pins 14 and the positioning pin sleeves 15. The two iron molds are provided with positioning pins and positioning pin sleeves on the inner diagonals. When the two iron molds are matched, the positioning pins on one side are embedded in the positioning pin sleeves on the other side. The iron mold 1 has positioning holes 16 on the four inner corners, and the positioning pins 14 and positioning pin sleeves 15 are arranged diagonally in the positioning holes 16. By inserting the positioning pins and positioning pin sleeves into the positioning holes, the positioning pins and positioning pin sleeves can be installed more stably, which facilitates the stable cooperation of the positioning pins and positioning pin sleeves.

[0032] The positioning pin 14 includes a pin base 141 fixed in the positioning hole 16. Figure 5 As shown, the pin base 141 has a cylindrical pin body 142; the positioning pin sleeve 15 includes a sleeve body 151, as shown in the attached Figure 4 As shown, the sleeve 151 has an elliptical hole 152 matched with the cylindrical pin body 142. In order to prevent the two iron molds from having different temperatures and inconsistent sizes after thermal expansion, so that the positioning pin and the positioning pin sleeve can still fit tightly, a cylindrical positioning pin and an elliptical positioning pin sleeve are used to match, and the elliptical hole of the positioning pin sleeve can leave a certain space for the cylindrical pin body, and the length direction of the elliptical hole coincides with the central diagonal of the iron mold, and the positioning pin is located on the other diagonal of the iron mold.

[0033] The casting method of the vertical double-layer casting device for shaft castings has the following specific steps:

[0034] Step 1: Place the iron mold on the mold plate support 20 of the model device. The model device is equipped with an electric heating pipe 19 to heat the model 18. After the iron mold 1 and the model 18 are molded together, a gap covered with a sand layer is formed between them; a cylinder 21 is installed on the mold plate support 20, as shown in the attached Figure 6As shown, the pressing plate 22 is used to press the side of the model and the iron mold. The pressing plate 22 presses the gap between the iron mold and the model to prevent sand from running out from the side when shooting sand; the coated sand is blown into the gap between the iron mold and the model from the sand shooting hole 23 of the iron mold by professional equipment. The coated sand solidifies and adheres to the iron mold when heated. After the coating layer is coated on the groove surface of the shaping groove, the straight runner groove and the horizontal runner groove of the iron mold, a double-sided sand core is placed between the iron molds on both sides. The coating layer and the double-sided sand core form a double-layer casting cavity, and the casting channel is also formed at this time;

[0035] Step 2, pour molten iron toward the pouring port, the molten iron flows into the upper and lower runners respectively through the sprue, and then flows through each runner cavity and the inner gate from the runner to the double-layer casting cavity, the molten iron fills the casting cavity from bottom to top, and the gas is discharged from the exhaust groove at the same time, waiting for the molten iron to cool, and the shaft casting is formed. The casting cavity is double-layered, and there is enough molten iron when injecting molten iron from the pouring port, which will generate enough heat to raise the temperature of the iron mold to 200-230°C, which is convenient for the next sand-covered molding, and the iron mold heating step is omitted.

[0036] Compared with the prior art, the present invention improves the process method for shaft castings on the basis of the iron mold sand coating process method, realizes the mechanized and efficient production of shaft castings, and improves the production efficiency and reduces the production scrap rate. At present, the two iron molds in the iron mold sand coating casting process are different, and two different iron molds need to be manufactured. In the present invention, two identical iron molds can be combined together, and only one model device is needed to match them, thus saving mold investment.

[0037] The working principle of the present invention is as follows: a coating layer is coated on the groove surfaces of the shaping groove, the straight runner groove and the transverse runner groove of the iron mold, a double-sided sand core is placed between the iron molds on both sides, the coating layer and the double-sided sand core form a double-layer casting cavity, and the casting channel is also formed at this time; molten iron is poured toward the pouring port, the molten iron flows into the upper and lower layers of the transverse runners respectively through the straight runner, and then flows to the double-layer casting cavity through the transverse runner through each transverse runner cavity and the inner gate, the molten iron fills the casting cavity from bottom to top, and this structural form enables the molten iron to fill the mold smoothly, greatly improving the quality of shaft castings, and by setting a double-layer casting cavity, double the number of shaft castings can be obtained, effectively improving production efficiency, and the entire casting process is simple and convenient.

[0038] The above embodiments only express the implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. In this embodiment, the words "up", "down", "left", "right", "front" and "rear" only represent their relative positions and do not represent their absolute positions. It should be pointed out that, for those of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A vertical double-layer casting device for shaft castings, Features: The invention is composed of two identical iron molds (1) which are molded together; the iron mold (1) has a plurality of shaping grooves (2); the middle part of the iron mold (1) has a straight runner groove (3); both sides of the straight runner groove (3) have transverse runner grooves (4) connected to the shaping grooves (2); the shaping grooves (2), the straight runner grooves (3) and the transverse runner grooves (4) are paved with a coating layer (5); a coating layer (5) is provided between the coating layers (5) of the two iron molds (1); A double-sided sand core (6), the coating layers (5) on both sides and the double-sided sand core (6) form two casting cavities (7); a pouring gate (8), a sprue (9), a cross runner (10) and a cross runner cavity (11) are arranged between the coating layers (5); the pouring gate (8), the sprue (9), the cross runner (10) and the cross runner cavity (11) are connected in sequence, and the cross runner cavity (11) is connected to the casting cavity (7).

2. The vertical double-layer casting device for shaft castings according to claim 1, Features: The pouring port (8) is in a trumpet shape that is larger on the outside and smaller on the inside.

3. The vertical double-layer casting device for shaft castings according to claim 1, Features: The inner side of the iron mold (1) has an exhaust groove (12) at one end corresponding to the casting cavity (7), and the exhaust grooves (12) on the iron molds (1) at both sides are combined to form an exhaust groove (13).

4. The vertical double-layer casting device for shaft castings according to claim 3, Features: The depth of the exhaust sub-groove (12) ranges from 0.14 to 0.16 mm, and the depth of the exhaust groove (13) ranges from 0.28 to 0.32 mm.

5. The vertical double-layer casting device for shaft castings according to claim 1, Features: Positioning pins (14) and positioning pin sleeves (15) are respectively arranged at the inner diagonals of the iron mold (1), and the iron molds (1) on both sides are connected through the cooperation of the positioning pins (14) and the positioning pin sleeves (15).

6. The vertical double-layer casting device for shaft castings according to claim 5, Features: The four inner corners of the iron mold (1) are provided with positioning holes (16), and the positioning pins (14) and positioning pin sleeves (15) are arranged diagonally in the positioning holes (16).

7. The vertical double-layer casting device for shaft castings according to claim 6, Features: The positioning pin (14) comprises a pin base (141) fixed in the positioning hole (16), and the pin base (141) has a cylindrical pin body (142); the positioning pin sleeve (15) comprises a sleeve body (151), and the sleeve body (151) has an elliptical hole (152) matching the cylindrical pin body (142).

8. A casting method for a vertical double-layer casting device for shaft castings according to any one of claims 1 to 7, Features: The specific steps are as follows: Step 1: Cover the groove surface of the molding groove, the straight runner groove and the transverse runner groove of the iron mold with a coating layer, and put a double-sided sand core between the iron molds on both sides. The coating layer and the double-sided sand core form a double-layer casting cavity, and the casting channel is also formed at this time; Step 2, pour molten iron toward the pouring gate, the molten iron flows into the upper and lower runners through the sprue, and then flows through each runner cavity and the inner gate from the runner to the double-layer casting cavity. The molten iron fills the casting cavity from bottom to top, and the gas is discharged from the exhaust groove at the same time. Wait for the molten iron to cool down, and the shaft casting is formed.

9. The vertical double-layer casting method for shaft castings according to claim 8, Features: In step 1, when the groove surfaces of the molding groove, the straight runner groove and the transverse runner groove of the iron mold are covered with a coating layer, the iron mold is placed on the mold plate bracket of the model device. The model device is equipped with an electric heating pipe to heat the model. After the iron mold and the model are molded together, a gap of a sand-covered layer is formed between them; a cylinder is installed on the mold plate bracket to press a pressing plate on the side of the model and the iron mold. The pressing plate presses the gap between the iron mold and the model to prevent sand from running out from the side when shooting sand. Use professional equipment to blow the coated sand from the sand shooting hole of the iron mold into the gap between the iron mold and the model. The coated sand solidifies and sticks to the iron mold when heated.

10. The vertical double-layer casting method for shaft castings according to claim 8, Features: In step 2, the casting cavity is double-layered, and there is enough molten iron when it is injected from the pouring port, which will generate enough heat to raise the temperature of the iron mold to 200-230°C, which is convenient for the next sand covering molding and eliminates the iron mold heating step.

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