Foundry mold and casting method for similar core blowing by replacement module

Abstract

This invention specifically relates to a casting mold and casting method for achieving similar core blowing through a replacement module, solving the problems of complex casting operations, low efficiency, and high cost for fuel pump cover-like parts used in aero-engine fuel accessory systems. The casting mold for achieving similar core blowing through a replacement module includes a fixed half-mold and a movable half-mold that mates with the fixed half-mold. The movable half-mold includes a riser module and a replacement module. The riser module is a cavity set on the mating surface of the movable half-mold. The replacement module is disposed within the cavity, and its outer wall is adapted to the inner wall of the cavity. The riser module is used to form a riser sleeve mold for the part to be cast when it mates with the fixed half-mold, and the replacement module is used to form an inner core mold for the part to be cast. The riser sleeve mold and the inner core mold form the core of the part to be cast, which is used to mate with a corresponding outer mold to cast different types of parts.

Description

TECHNICAL FIELD

[0001] The present application relates to a foundry mold and a foundry method for similar core blowing by replacing a module. BACKGROUND

[0002] A core box is a mold for core blowing to form the inside of a cast part. After core blowing, the core is polished and baked, and then assembled into a metal mold, and finally, a metal cast part is formed through a pouring process. A general core box design should include eight subsystem components, such as a sand shooting plate, an equipment connecting plate, a fixed mold, a fixed mold ejection system, a movable mold, a movable mold ejection system, an electric heating rod, and a thermocouple. In the conventional design, the fixed mold and the movable mold are each an integral whole. First, the core mold is installed on a core shooter, and the movable mold is moved to the parting surface of the fixed mold to perform mold closing by a hydraulic system of the core shooter. After the fixed mold and the movable mold are closed, the power of the electric heating rod is turned on to heat the fixed mold and the movable mold to a temperature of 200℃ to 300℃. Then, coated sand is blown into the core cavity through the core shooting plate, and the blowing pressure is controlled at 0.3MPa to 0.5MPa, and the blowing time is controlled at 3s to 10s. After blowing is completed, the core is hardened for 3min to 10min, and then the movable mold is opened to take out the core, and core blowing is completed.

[0003] In the fuel accessory system of an aero-engine, various types of oil pump cover parts are used, which are basically similar in structure and size, and only have local differences. The oil pump cover parts are usually manufactured by casting, and the cast parts of the oil pump cover parts are formed by a metal mold, and the internal structure of the oil pump cover parts is formed by a core, which has the problems of complex casting operation, low efficiency, and high cost. SUMMARY

[0004] The purpose of the present application is to solve the problems of complex casting operation, low efficiency, and high cost of the oil pump cover parts used in the fuel accessory system of an aero-engine, and to provide a foundry mold and a foundry method for similar core blowing by replacing a module, which can quickly blow three different types of cores to reduce the production cost of the mold.

[0005] To solve the above technical problems, the technical solution adopted by the present application is:

[0006] A foundry mold for similar core blowing by replacing a module, comprising a fixed mold and a movable mold that is matched and connected to the fixed mold, and the special feature is that:

[0007] The movable half mold comprises a riser module and a replacement module; the riser module is a concave cavity arranged on the joint surface of the movable half mold; the replacement module is arranged in the concave cavity, and the outer wall of the replacement module is matched with the inner wall of the concave cavity; one end of the replacement module is connected with the bottom of the concave cavity, and the other end is a joint surface matched with the fixed half mold;

[0008] The riser module is used to form a riser sleeve mold of the to-be-cast workpiece matched with the fixed half mold, and the replacement module is used to form an inner core mold of the to-be-cast workpiece.

[0009] The riser sleeve mold and the inner core mold form a core of the to-be-cast workpiece, which is used to cooperate with a corresponding outer mold to cast different types of to-be-cast workpieces.

[0010] Further, an error prevention protrusion and a positioning groove matched with the error prevention protrusion are further included.

[0011] The error prevention protrusion is arranged on the inner side wall of the riser module.

[0012] The positioning groove is arranged on the outer side wall of the replacement module corresponding to the error prevention protrusion, and the positioning groove is matched with the error prevention protrusion.

[0013] Further, the error prevention protrusion comprises a first protrusion, a second protrusion and a third protrusion arranged on the inner side wall of the riser module.

[0014] The positioning groove comprises a first groove, a second groove and a third groove arranged on the outer side wall of the replacement module.

[0015] The first groove, the second groove and the third groove are respectively matched with the first protrusion, the second protrusion and the third protrusion in position.

[0016] Further, the first protrusion and the first groove are clearance matched.

[0017] The second protrusion and the second groove are clearance matched.

[0018] The third protrusion and the third groove are clearance matched.

[0019] Further, the first protrusion and the second protrusion are both R30 circular arc structures.

[0020] The third protrusion is a 30*8 cuboid structure.

[0021] Further, a positioning module arranged on the inner side wall of the riser module is further included, the positioning module is a semicircular groove communicated with the riser module, and is used to form a positioning column.

[0022] Further, a type number is arranged on the joint surface of the replacement module.

[0023] Further, the riser module and the replacement module are connected by three countersunk screws arranged along the circumference, and the countersunk screws are located between the joint surfaces of the movable half mold and the fixed half mold; the included angle between adjacent countersunk screws is 120°.

[0024] In addition, the application also provides a casting method for realizing similar core blowing by a replacement module, based on the casting mold for realizing similar core blowing by a replacement module, and the special features are as follows:

[0025] 1) connecting the riser module and the replacement module, and then connecting the movable half mold and the fixed half mold, and preheating;

[0026] 2) blowing the core and hardening;

[0027] 3) after taking out the core hardened in step 2), polishing and cleaning the core, and baking;

[0028] 4) after matching the core obtained in step 3) with the corresponding outer mold, preheating, and then casting and filling;

[0029] 5) taking out the core and the castings from the outer mold, cutting the riser of the castings, and then solid solution and aging treatment, finally blowing the core and cleaning the castings, and completing the casting.

[0030] Further, step 1) is specifically as follows:

[0031] The riser module and the replacement module are connected by the countersunk screws, and then the movable half mold and the fixed half mold are connected, and then the movable half mold and the fixed half mold are preheated by the heating rod, and the preheating temperature is 220±10℃;

[0032] Step 2) is specifically as follows:

[0033] The blowing pressure is set to 0.3-0.5MPa, the hardening time is set to 4-6min, and then the core blowing machine is used to blow the core and harden;

[0034] Step 3) is specifically as follows:

[0035] After taking out the core hardened in step 2), the core flash is polished and cleaned, when the core temperature is less than or equal to 100℃, the core is loaded into the resistance furnace, and then the temperature is raised to the baking temperature of 160±10℃, and the temperature is kept for 1h, and then the temperature is cooled for use;

[0036] Step 4) is specifically as follows:

[0037] After matching the core obtained in step 3) with its corresponding outer mold, preheating is started to a temperature of 300±10℃, and then aluminum alloy molten metal is poured and filled to obtain the core and the casting part; the temperature of the aluminum alloy molten metal is 710℃ and the filling time is 6s.

[0038] Compared with the prior art, the beneficial effects of the technical solution of the present invention are:

[0039] (1) The present invention realizes the casting mold for blowing similar cores by replacing the module. The moving half mold is set as the riser module and the replacement module. Different types of cores can be quickly produced by replacing the replacement module. Then, the cores are matched with the corresponding outer molds to produce different types of castings. The casting operation of oil pump cover parts used in the fuel accessory system of aero-engine is simplified.

[0040] (2) The present invention realizes the casting mold for blowing similar cores by replacing modules. In order to distinguish different replacement modules and prevent mistaking, model numbers are engraved on different replacement modules. The model numbers are located between the mating surfaces of the moving half mold and the fixed half mold. The model numbers on the replacement modules are set as raised structures. The model numbers on the blown riser sleeve are recessed and will not affect the fit between the core and the outer mold.

[0041] (3) This invention achieves similar core blowing casting mold by replacing modules. The riser module can replace the traditional asbestos cloth and heat insulation coating to keep the riser part of the casting insulated. During the pouring and solidification of the casting, a temperature gradient from top to bottom is formed, so that the feeding channel is unobstructed and the riser of the casting can play a good feeding role. It can also be used for positioning. Since there is no contact between the inner core of the casting formed by blowing and the outer mold, it is impossible to position it. Therefore, the riser of the casting and its inner core are blown into one piece. When the riser sleeve mold formed by the riser module is positioned on the outer mold, the positioning of the inner core of the casting is indirectly realized, which perfectly solves the core positioning problem.

[0042] (4) The present invention realizes a similar core blowing casting method by replacing modules. In actual production, the cost of manufacturing a mold for a part to be cast is about 160,000 yuan. However, the moving half mold of the present invention can realize the replacement of three replacement modules at one time, that is, one moving half mold can produce three different types of cores, saving an economic benefit of 16*2=320,000 yuan, which greatly reduces the cost.

[0043] (5) The present invention realizes a similar core blowing casting method by replacing the module, which can be applied to the production of other castings with similar core structures, and has strong versatility. Attached Figure Description

[0044] Figure 1This is a schematic diagram of the structure of a casting mold embodiment of the present invention that achieves similar core blowing by replacing modules.

[0045] Figure 2 This is a schematic diagram of the structure of the moving half mold inner core in an embodiment of the present invention that achieves similar core blowing by replacing modules.

[0046] Figure 3 This is a schematic diagram of the mating surface between the moving half-mold and the fixed half-mold core in an embodiment of the casting mold for achieving similar core blowing by replacing modules according to the present invention.

[0047] Figure 4 This is a perspective view of the first replacement module in an embodiment of the present invention for casting molds that achieve similar core blowing by replacement modules.

[0048] Figure 5 This is a schematic diagram of the structure of the first replacement module in an embodiment of the present invention for achieving similar core blowing through a replacement module in a casting mold.

[0049] Figure 6 This is a schematic diagram of the structure of the second replacement module in an embodiment of the present invention for achieving similar core blowing through a replacement module in a casting mold.

[0050] Figure 7 This is a schematic diagram of the third replacement module in an embodiment of the present invention for achieving similar core blowing through a replacement module in a casting mold.

[0051] Figure 8 This is a schematic diagram of the structure of the first type of core in the embodiment of the casting mold for blowing similar cores by replacing modules according to the present invention.

[0052] Figure 9 This is a schematic diagram of the structure of the second type of core in the embodiment of the casting mold for blowing similar cores by replacing modules according to the present invention.

[0053] Figure 10 This is a schematic diagram of the third type of core in an embodiment of the casting mold for blowing similar cores by replacing modules according to the present invention.

[0054] Figure 11 This is a schematic diagram of the external mold structure that mates with the first type of core in an embodiment of the casting mold for blowing similar cores by replacing modules according to the present invention.

[0055] Figure 12 This is a schematic diagram of the external mold structure that mates with the second type of core in an embodiment of the casting mold for blowing similar cores by replacing modules according to the present invention.

[0056] Figure 13This is a schematic diagram of the external mold structure that mates with a third type of core in an embodiment of the casting mold for blowing similar cores by replacing modules according to the present invention.

[0057] Figure 14 This is a schematic diagram (with riser) of the first type of aluminum alloy casting produced in an embodiment of the present invention that achieves similar core blowing by replacing modules.

[0058] Figure 15 This is a schematic diagram (with riser) of the second type of aluminum alloy casting produced in an embodiment of the present invention that achieves similar core blowing by replacing modules.

[0059] Figure 16 This is a schematic diagram (with riser) of the third type of aluminum alloy casting produced in an embodiment of the present invention that achieves similar core blowing by replacing modules.

[0060] The attached figures are labeled as follows:

[0061] 1-Moving half mold, 2-Fixed half mold, 3-Riser module, 4-Replacement module, 5-Riser sleeve mold, 6-Inner core mold, 7-Outer mold, 8-Model number, 9-Anti-error protrusion, 91-First protrusion, 92-Second protrusion, 93-Third protrusion, 10-Positioning groove, 101-First groove, 102-Second groove, 103-Third groove, 11-Core shooting plate, 12-Moving half mold ejection system, 13-Thermocouple, 14-Fixed half mold spring return system, 15-Guide post, 16-Return rod. Detailed Implementation

[0062] like Figures 1 to 3 As shown, a casting mold for achieving similar core blowing by replacing modules includes a fixed half mold 2 and a movable half mold 1 that mates with the fixed half mold 2, an error prevention module, and a positioning module;

[0063] First, the moving half mold 1 includes a riser module 3 and a replacement module 4; the riser module 3 is a cavity provided on the mating surface of the moving half mold 1; the replacement module 4 is disposed in the cavity, and the outer wall of the replacement module 4 is adapted to the inner wall of the cavity; one end of the replacement module 4 is connected to the bottom of the cavity, and the other end is a mating surface that mates with the fixed half mold 2; the riser module 3 is used to mate with the fixed half mold 2 to form a riser sleeve mold 5 for the casting to be made, and the replacement module 4 is used to form an inner core mold 6 for the casting to be made; the riser sleeve mold 5 and the inner core mold 6 form the core of the casting to be made, and the core is used to mate with the corresponding outer mold 7 to cast different types of castings.

[0064] Secondly, since the core of the casting is asymmetrical, a fault-prevention structure is required. In this embodiment, the fault-prevention module includes fault-prevention protrusions 9 and positioning grooves 10 that match the fault-prevention protrusions 9. The fault-prevention protrusions 9 include a first protrusion 91, a second protrusion 92, and a third protrusion 93 located on the inner wall of the riser module 3. The positioning grooves 10 include a first groove 101, a second groove 102, and a third groove 103 located on the outer wall of the replacement module 4. The first groove 101, the second groove 102, and the third groove 103 correspond to and match the positions of the first protrusion 91, the second protrusion 92, and the third protrusion 93, respectively. The first protrusion 91 and the second protrusion 92 are both arc structures with an radius of 30 (R30); the third protrusion 93 is a cuboid structure with a radius of 30*8 (30*8).

[0065] The replacement module 4 is designed with a recessed shape at the corresponding position, allowing for a clearance fit between the two at room temperature. Specifically, the first protrusion 91 and the first groove 101 are clearance fitted, the second protrusion 92 and the second groove 102 are clearance fitted, and the third protrusion 93 and the third groove 103 are clearance fitted, making the fit between the replacement module 4 and the riser module 3 more accurate. Furthermore, the installation position is unique when replacing any one of the replacement modules 4; during core blowing, there will be no deviation in the positional dimensions of the riser module 3 and the inner core of the casting, or even misinstallation.

[0066] The inner core cavity of the moving half mold 1 is designed as a riser module 3 and a replacement module 4; the riser module 3 and the replacement module 4 are connected by three countersunk screws evenly distributed along the circumference; the three countersunk screws are each at a 120° angle; the specification of each countersunk screw is M8*30. In order to prevent the coated sand from being blown into the countersunk screw holes, when setting the position of the countersunk screw holes on the moving half mold 1, the countersunk screw holes are designed between the mating surfaces of the moving half mold 1 and the fixed half mold 2, and should not be exposed in the cavity of the core to avoid the defect of the core being too full.

[0067] like Figure 2 As shown, the inner core cavity of the moving half mold 1 is provided with three positions for blown cores. In other embodiments, one or two positions may also be provided. The purpose is to enable the replacement module 4 to be quickly replaced, thereby producing cores of different models. The cores then cooperate with the corresponding outer mold 7 to produce castings of different models.

[0068] like Figure 4 , Figure 5 , Figure 6 , Figure 7As shown, various cores with similar shapes and structures and minor dimensional differences can be blown by replacing different replacement modules 4. When the fixed half mold 2 has three positions for blown cores, the three types of replacement modules 4 can be quickly replaced, enabling the production of three different types of cores at once. To distinguish the different replacement modules 4 and prevent misuse, model numbers 8 are engraved on the mating surfaces of the different replacement modules 4, located between the mating surfaces of the moving half mold 1 and the fixed half mold 2. The model number 8 on the replacement module 4 is a raised structure, so that the model number 8 on the blown riser sleeve is recessed, thus not affecting the fit between the riser sleeve and the outer mold 7.

[0069] like Figure 8 , Figure 9 , Figure 10 As shown, the core is formed by a riser sleeve mold 5 and an inner core mold 6; the riser module 3 is used to cooperate with the fixed half mold 2 to form the riser sleeve mold 5 of the part to be cast, and the replacement module 4 is used to form the inner core mold 6 of the part to be cast; by replacing different inner core molds 6, different types of cores can be blown. In this embodiment, three different types of cores can be blown by replacing different inner core molds 6. The riser sleeves of the parts to be cast cast by these three types of cores are exactly the same in size and shape, the only difference is that they are used to form the inner core of the part to be cast.

[0070] The riser module 3 has two functions. The first function is to replace the traditional asbestos cloth and thermal insulation coating to insulate the riser part of the casting. During the pouring and solidification process of the casting, a temperature gradient from top to bottom is formed, which makes the feeding channel unobstructed and allows the riser of the casting to play a good feeding role. The second function is positioning. Since there is no contact between the inner core of the casting formed by blowing and the outer mold 7, it is impossible to position it. Therefore, the riser sleeve of the casting and its inner core are blown into one piece. The riser sleeve mold 5 formed by the riser module 3 is positioned on the outer mold 7, which indirectly realizes the positioning of the inner core of the casting and perfectly solves the positioning problem of the core.

[0071] like Figure 11 , Figure 12 , Figure 13As shown, to accurately position the inner core mold 6, the mating surface between the core and the outer mold 7 cannot be designed as a rotating structure. Instead, a Φ100 semi-cylindrical shape, i.e., a positioning module, needs to be added to the inner wall of the riser module 3 along the outer edge of the rotating structure. The positioning module is a semi-circular groove connected to the riser module 3, forming a positioning post. The distance between the positioning module and the center of the core is 170mm, and the connecting part is connected with a chamfered R10 transition. At the corresponding position on the outer mold 7, the semi-cylindrical shape is removed. When installing the core, the riser module 3 is fitted onto the outer mold 7 according to its corresponding shape and position. This design ensures accurate positioning of the core and the outer mold 7, thereby guaranteeing the positional and dimensional accuracy of the inner core and the outer mold 7.

[0072] In addition, the present invention also provides a casting method for achieving similar core blowing by replacing module 4, based on the casting mold for achieving similar core blowing by replacing module 4 described above, including the following steps:

[0073] 1) Install the core onto the core-shooting plate 11 and flip the moving half mold 1 to a horizontal position; take out the replacement module 4 of the model to be produced; align the replacement module 4 with the installation position and use countersunk screws to install the replacement module 4 into the riser module 3 on the moving half mold 1. After connection, the moving half mold 1 is connected to the fixed half mold 2 through the moving half mold ejection system, guide post 15 and reset rod 16. Then use heating rods to preheat the moving half mold 1 and the fixed half mold 2. Monitor the preheating temperature through thermocouple 13 until the preheating temperature is 220±10℃.

[0074] 2) Set the blowing pressure to 0.4 MPa and the hardening time to 5 min, then use the core shooter 11 to start blowing the core and wait for the core shell to harden;

[0075] 3) Take out the core after it has been hardened in step 2). After the core temperature drops, grind and clean the seams of the core. When the core temperature is less than or equal to 100℃, put the core into the resistance heating furnace and then heat it to the baking temperature of 160±10℃. Hold it for 1 hour. After the holding time is over, let it cool with the resistance heating furnace for later use.

[0076] 4) Lift the outer mold 7 corresponding to the core obtained in step 3), fit it properly, and install it on the casting machine. Start preheating to a temperature of 300±10℃, and then cast and fill the mold to obtain the core and the casting part. In this embodiment, aluminum alloy molten metal is preferably used for casting and filling, wherein the temperature of the aluminum alloy molten metal is 710℃ and the filling time is 6s.

[0077] 5) Remove the core and the part to be cast obtained in step 4) from the outer mold 7, cut the riser of the part to be cast, and perform solution treatment and aging treatment. Finally, blow out the core and clean the part to be cast to obtain the desired result. Figure 14 ,Figure 15 , Figure 16 The aluminum alloy casting shown is ejected from the fixed half mold 2 by the fixed half mold spring reset system, thus completing the casting process.

[0078] Using the method of the present invention, different types of cores can be blown according to different replacement modules 4; by removing the cores and installing them on the corresponding type of mold, different types of castings can be produced.

Claims

1. A casting mold for similar core blowing by replacing the mold module, comprising a fixed mold half (2) and a movable mold half (1) which is matched with the fixed mold half (2), characterized in that: the movable mold half (1) comprises a riser module (3) and a replacement module (4); the riser module (3) is a concave cavity provided on the joint surface of the movable mold half (1); the replacement module (4) is arranged in the concave cavity, and the outer wall of the replacement module (4) is matched with the inner wall of the concave cavity; one end of the replacement module (4) is connected with the bottom of the concave cavity, and the other end is a joint surface matched with the fixed mold half (2); a positioning module is arranged on the inner side wall of the riser module (3), and the positioning module is a semicircular groove which is communicated with the riser module (3) and is used for forming a positioning column; the riser module (3) is used for forming a riser sleeve mold (5) of a to-be-cast part with the fixed mold half (2), and the replacement module (4) is used for forming an inner core mold (6) of the to-be-cast part; the riser sleeve mold (5) and the inner core mold (6) form a core of the to-be-cast part, and the core is used for being matched with a corresponding outer mold (7) to cast different types of to-be-cast parts; further comprising an error prevention protrusion (9) and a positioning groove (10) matched with the error prevention protrusion (9); the error prevention protrusion (9) is arranged on the inner side wall of the riser module (3); the positioning groove (10) is arranged on the outer side wall of the replacement module (4) corresponding to the error prevention protrusion (9), and the positioning groove (10) is matched with the error prevention protrusion (9); the error prevention protrusion (9) comprises a first protrusion (91), a second protrusion (92) and a third protrusion (93) arranged on the inner side wall of the riser module (3); the positioning groove (10) comprises a first groove (101), a second groove (102) and a third groove (103) arranged on the outer side wall of the replacement module (4); the first groove (101), the second groove (102) and the third groove (103) are respectively matched with the first protrusion (91), the second protrusion (92) and the third protrusion (93) in position; the first protrusion (91) and the first groove (101) are clearance matched; the second protrusion (92) and the second groove (102) are clearance matched; the third protrusion (93) and the third groove (103) are clearance matched; the first protrusion (91) and the second protrusion (92) are both circular arc structures; and the third protrusion (93) is a cuboid structure.

2. The casting mold for similar core blowing by replacing the mold module according to claim 1, characterized in that: a type number (8) is arranged on the joint surface of the replacement module (4).

3. The casting mold for similar core blowing by replacing the mold module according to claim 1 or 2, characterized in that: the riser module (3) and the replacement module (4) are connected through three countersunk head screws arranged along the circumference, and the countersunk head screws are located between the joint surfaces of the movable mold half (1) and the fixed mold half (2); the included angle between adjacent countersunk head screws is 120°. comprising the following steps:

4. A casting method by replacing a mold for similar core blowing based on the casting mold by replacing a mold for similar core blowing according to any one of claims 1 to 3, characterized in that, ​ 1) connecting the riser module (3) and the replacement module (4), after connecting, the movable half mold (1) and the fixed half mold (2) are docked and preheated; 2) blowing the core and hardening; 3) after taking out the core hardened in step 2), polishing, cleaning and baking are performed; 4) after the core obtained in step 3) is matched with its corresponding outer mold (7), preheating is started, and after preheating, casting and filling are performed; 5) the core obtained in step 4) and the castings are taken out from the outer mold (7), the riser of the castings is cut, and solid solution and aging treatment are performed, finally the core is blown out and the castings are cleaned, and the casting is completed.

5. The casting method for blowing similar cores by replacement module according to claim 4, wherein: Step 1) is specifically: The riser module (3) and the replacement module (4) are connected by means of countersunk head screws, after connecting, the movable half mold (1) and the fixed half mold (2) are docked, and then the movable half mold (1) and the fixed half mold (2) are preheated by using a heating rod, the preheating temperature is 220±10℃; Step 2) is specifically: The blowing pressure is set to 0.3-0.5MPa, the hardening time is set to 4-6min, then the core blowing machine is used to start blowing the core and hardening; Step 3) is specifically: After taking out the core hardened in step 2), the core is polished and cleaned, when the core temperature is less than or equal to 100℃, the core is loaded into an electric resistance furnace, then the temperature is raised to a baking temperature of 160±10℃, and the temperature is maintained for 1h, after maintaining the temperature, it is cooled and used; Step 4) is specifically: After the core obtained in step 3) is matched with its corresponding outer mold (7), preheating to a temperature of 300±10℃ is started, then aluminum alloy liquid metal is poured and filled to obtain the core and the castings; the temperature of the aluminum alloy liquid metal is 710℃, and the filling time is 6s.

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