Manufacturing method of mold core assembly

Abstract

The manufacturing method comprises the following steps that a mold core is designed, specifically, the mold core assembly comprises a sand mold and a sand core, a transparent door structure is designed at one end of the sand core, and a cantilever structure is designed at the other end of the sand core; the transparent door structure is provided with a first hole, the sand mold is provided with a second hole, and the first hole is communicated with the second hole; mold core manufacturing: a sand mold and a sand core are manufactured respectively, and the first hole and the second hole are taken out together; mold core combination: the sand core is combined on the sand mold, and a cushion block is cushioned between the cantilever structure and the sand mold; and the core rod is inserted into the first hole and the second hole, the first hole and the second hole are filled with resin sand, and after the resin sand is solidified, the cushion block is removed. According to the manufacturing method of the mold core assembly, in the mold core combination step, the sand mold and the sand core are connected into a whole through the core rod and the resin sand, the fixing problem of the cantilever sand core in sand mold casting is effectively solved, the casting cost is low, the quality risk is small, and operation is easy.

Description

Technical Field

[0001] The invention relates to the technical field of casting, in particular to a method for manufacturing a core component with a cantilever structure. Background Art

[0002] A certain type of thin-walled casting has a hollow structure, in which the top and bottom surfaces of the hollow structure have no through-doors, and only one side of the side has a through-door, and the through-door is relatively small. During the sand casting process of such thin-walled castings, the non-through-door end of the sand core used to form the hollow structure is a cantilever structure, which is prone to displacement, deformation, and fracture during the core assembly and pouring process, resulting in casting defects or even scrapping of the casting. In the prior art, two methods are usually used to mitigate the casting defects caused by such cantilever sand cores.

[0003] One is to lengthen and enlarge the core head connected to the door, so that the center of gravity of the sand core is biased to one side of the core head after the core is placed, and the sand core is relatively stable. This method of lengthening and enlarging the core head increases the sand consumption of the sand core, increases the sand-iron ratio, and increases the amount of sand and binder used, resulting in an increase in casting costs; and in this way, the risk of sand core displacement is still relatively high due to the buoyancy of the molten metal during the pouring process.

[0004] The other method is to fix the core head by screw marking. This method is complicated to operate. The sand box needs to be propped up to operate the screw and its matching parts at the bottom, or the sand box needs to be turned over many times to connect and tighten the screw. The sand core is easily damaged due to over-tightening during the screw tightening process. In addition, during the pouring process, the molten metal in the cavity is easy to leak out from the screw hole. Summary of the invention

[0005] Based on this, it is necessary to provide a method for manufacturing a core assembly with a cantilever structure in order to solve the above technical problems.

[0006] In order to solve the above problems, the present invention adopts the following technical solutions:

[0007] The embodiment of the present invention discloses a method for manufacturing a core assembly, comprising the following steps:

[0008] Core design, the core assembly includes a sand mold and a sand core, one end of the sand core is designed with a through-door structure, and the other end is designed with a cantilever structure; the through-door structure is designed with a first hole, the sand mold is designed with a second hole, and the first hole and the second hole are designed to be connected;

[0009] Core making, making the sand mold and the sand core respectively, and taking out the first hole and the second hole together;

[0010] A core assembly, wherein the sand core is assembled to the sand mold, and a pad is inserted between the cantilever structure and the sand mold; a core rod is inserted into the first hole and the second hole, and resin sand is filled into the first hole and the second hole, and after the resin sand is cured, the pad is removed.

[0011] In one embodiment, a core head is provided at the end of the through-door structure, and the first hole crosses the through-door structure and the core head; the sand mold is provided with a positioning groove matching the core head, and the second hole is provided at the bottom of the positioning groove.

[0012] In one embodiment, a positioning structure for the core rod is disposed at the bottom of the second hole.

[0013] In one embodiment, a core-bone component is disposed in the sand core.

[0014] In one of the embodiments, the core bone assembly includes a core bone and a connecting ring fixed to the core bone, the core bone is arranged in the cantilever structure, and the connecting ring is arranged in the first hole and coaxial with the first hole; in the core assembly step, when the core rod is inserted into the first hole, it is simultaneously inserted into the connecting ring.

[0015] In one embodiment, the cushion block is designed to conform to the cantilever structure and the sand mold.

[0016] In one embodiment, there are multiple spacers.

[0017] In one embodiment, the size and material of the core rod are sufficient to support the torsional stress of the cantilever structure.

[0018] In one embodiment, the core rod is made of cast iron.

[0019] The technical solution adopted by the present invention can achieve the following beneficial effects:

[0020] The manufacturing method of the core assembly disclosed in the present invention connects the sand mold and the sand core into one by inserting a core rod and resin sand behind the first hole and the second hole in the core assembly step, thereby effectively solving the problem of fixing the cantilever sand core in sand casting, with low casting cost, small quality risk and simple operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 A cross-sectional view of a core assembly disclosed in an embodiment of the present invention;

[0022] Figure 2 A top view of a core assembly disclosed in an embodiment of the present invention;

[0023] Description of reference numerals:

[0024] 100-sand core, 110-transparent door structure, 120-cantilever structure, 130-core head, 140-first hole;

[0025] 200-sand mold, 210-positioning groove, 220-second hole;

[0026] 300-mandrel;

[0027] 400- pad;

[0028] 500-In-hole resin sand. DETAILED DESCRIPTION

[0029] In order to facilitate the understanding of the present invention, the present invention will be described more fully below with reference to the relevant drawings. The preferred embodiments of the present invention are given in the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present invention more thoroughly understood.

[0030] It should be noted that when an element is referred to as being "disposed on" another element, it may be directly on the other element or there may be a centered element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a centered element at the same time. The terms "vertical", "horizontal", "left", "right", "top", "bottom", "bottom end", "top end" and similar expressions used herein are for illustrative purposes only and are not intended to be the only implementation method.

[0031] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0032] An embodiment of the present invention discloses a method for manufacturing a core assembly, including core design, core production and core assembly.

[0033] Core design, such as Figure 1 , Figure 2As shown, the core assembly includes a sand mold 200 and a sand core 100. The sand mold 200 is used to form the overall structure of the casting, that is, the outer structure of the casting; the sand core 100 is used to form the local structure of the casting, that is, the hollow inner cavity structure of the casting. The hollow inner cavity structure has a through door (opening of the inner cavity of the casting) on ​​only one side. Correspondingly, a through door structure 110 is designed at one end of the sand core 100, which is used to form the through door part of the casting during the casting process and to support and position the sand mold 200 and the sand core 100 during the core assembly process; the other end of the sand core 100 should be designed as a cantilever structure 120. During the core assembly process, the cantilever structure 120 is suspended in the mold cavity of the sand mold 200 and does not contact the sand mold 200.

[0034] The first hole 140 is designed at the through-door structure 110 of the sand core 100, and both ends of the first hole 140 are open; the second hole 220 is designed at the corresponding part of the through-door structure 110 of the sand mold 200, and the second hole 220 can be open at one end and coaxial and connected with the first hole 140. The purpose of designing the first hole 140 and the second hole 220 is to connect and fix auxiliary components between the post-placed sand core 100 and the sand mold 200 in the subsequent core assembly process.

[0035] In the embodiments disclosed in the present invention, the sand core 100 may also be designed with a core head 130 for positioning the core assembly between cores. Specifically, the outer end of the transparent door structure 110 of the sand core 100 may be designed with a core head 130, and the sand mold 200 is designed with a positioning groove 210 matching the core head 130, which is used for positioning and limiting the core in the subsequent core assembly process. The second hole 220 may be designed at the bottom of the positioning groove 210, and its opening is located at the bottom of the positioning groove 210. Correspondingly, the first hole 140 should pass through the transparent door structure 110, the core head 130 and be connected to the second hole 220.

[0036] Furthermore, the core head 130 is tip-shaped, that is, the cross-sectional area of ​​the core head 130 gradually increases along the direction toward the side of the door structure 110; correspondingly, the positioning groove 210 is a structure that gradually increases along its opening direction, so that during the core assembly process, the core head 130 can be positioned into the positioning groove 210 without hindrance.

[0037] The core making process may include a sand box molding step for making the sand mold 200 and a core box making step for making the sand core 100, as follows:

[0038] Sand box molding, using the mold of the casting and a matching sand box, resin sand molding is used to make a sand mold 200. Among them, the positioning groove 210 and the second hole 220 can be taken out together during the molding process.

[0039] Core box core making, using a core box, using resin sand to make a sand core 100. Among them, the core head 130 and the first hole 140 can be taken out together during the core making process. In addition, a core bone component (not shown in the figure) can also be inserted into the sand core 100 in this step to strengthen the sand core 100, especially the cantilever structure 120, to prevent it from deformation, fracture, etc. during the subsequent core assembly and casting process.

[0040] Furthermore, the core bone assembly may include a core bone and a connecting ring, and the connecting ring is fixed to one end of the core bone; during the core making process, the core bone assembly is placed in the core box in advance, filled with sand to make the core, and the core box is removed after the resin sand is cured, and the core bone assembly is implanted in the sand core 100. The core bone is implanted in the cantilever structure 120, which can be used to strengthen the cantilever structure 120; the connecting ring is implanted in the corresponding part of the transparent door structure 110, which is used for the connection between the core bone assembly and the core rod 300; the connecting ring and the first hole 140 should be coaxially arranged, and the inner ring of the connecting ring can be exposed in the first hole 140.

[0041] The core assembly, i.e., core assembly, is to combine the sand core 100 with the sand mold 200. In this embodiment, the core assembly process can not only combine the sand core 100 and the sand mold 200 together, but also bond the two together. The specific steps of the core assembly can be as follows:

[0042] First, the core head 130 can be used to position and assemble the sand core 100 to the corresponding part of the sand mold 200. At this time, since the cantilever structure 120 is suspended in the air, a pad 400 can be placed at each of the two corners of the cantilever structure 120 to support the cantilever structure 120. The upper surface of the pad 400 can be designed to conform to the corner of the cantilever structure 120, and the lower surface of the pad 400 can be designed to conform to the local sand mold 200 in contact with it, and the thickness of the pad 400 can match the designed spacing between the cantilever structure 120 and the sand mold 200.

[0043] It should be noted that the present embodiment does not impose any specific restrictions on the number of cushion blocks 400 and their cushioning positions, and they can be adaptively changed according to the core structure.

[0044] In addition, after the sand core 100 is assembled to the corresponding part of the sand mold 200, the first hole 140 and the second hole 220 are connected and aligned. The best state is that the first hole 140 and the second hole 220 are coaxially arranged and the cross-section of the connecting openings of the two is the same. The mandrel 300 is inserted from the opening end of the first hole 140 away from the second hole 220 to the bottom of the second hole 220. The length of the mandrel 300 is greater than the depth of the second hole 220 and less than the sum of the depths of the first hole 140 and the second hole 220. Of course, since the connecting ring of the core bone component is coaxially arranged with the first hole 140, the mandrel 300 is also inserted into the connecting ring synchronously, so that the mandrel 300 is connected to the sand core 100 of the core bone component.

[0045] Then, the premixed resin sand is filled into the second hole 220 and the first hole 140 from the opening end of the first hole 140 away from the second hole 220, and the sand is filled and compacted. After the resin sand 500 in the hole is solidified, the sand core 100 and the sand mold 200 can be bonded together, and the core rod 300 and / or the core bone component are used to strengthen and connect the two. After the spacer 400 is removed, the matching position and size between the cores will not change.

[0046] In this embodiment, the core head 130 does not need to be made too large. Through the integral connection between the core components and the reinforcement of the core rod 300 and the core bone, the cantilever sand core can be fixed relative to the sand mold 200, effectively improving the quality of the casting.

[0047] Furthermore, in order to improve the use strength of the mandrel 300 and its compatibility with the core assembly, the size and material of the mandrel 300 should be designed to be sufficient to support the torque stress caused by the cantilever structure 120 of the sand core 100. The mandrel 300 is preferably made of cast iron.

[0048] In the embodiment disclosed in the present invention, a positioning structure may be provided at the bottom of the second hole 220, and the positioning structure matches the end of the core rod 300. When the core rod 300 is inserted into the first hole 140 and the second hole 220, the positioning and limiting are performed by the positioning structure and the connecting ring.

[0049] The above-mentioned embodiments only express several 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. It should be pointed out that, for ordinary technicians in this field, 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 method for manufacturing a core assembly, characterized in that: The following steps are involved: Core design, the core assembly includes a sand mold and a sand core, one end of the sand core is designed with a through-door structure, and the other end is designed with a cantilever structure; the through-door structure is designed with a first hole, the sand mold is designed with a second hole, and the first hole and the second hole are designed to be connected; Core making, making the sand mold and the sand core respectively, and taking out the first hole and the second hole together; A core assembly, wherein the sand core is assembled to the sand mold, and a pad is inserted between the cantilever structure and the sand mold; a core rod is inserted into the first hole and the second hole, and resin sand is filled into the first hole and the second hole, and after the resin sand is cured, the pad is removed.

2. The method for manufacturing a core assembly according to claim 1, characterized in that: A core head is arranged at the end of the through-door structure, and the first hole passes through the through-door structure and the core head; the sand mold is provided with a positioning groove matching the core head, and the second hole is arranged at the bottom of the positioning groove.

3. The method for manufacturing a core assembly according to claim 2, characterized in that: A positioning structure for the core rod is arranged at the bottom of the second hole.

4. The method for manufacturing a core assembly according to claim 1, characterized in that: A core bone component is arranged in the sand core.

5. The method for manufacturing a core assembly according to claim 4, characterized in that: The core bone assembly comprises a core bone and a connecting ring fixed to the core bone, the core bone is arranged in the cantilever structure, and the connecting ring is arranged in the first hole and is coaxial with the first hole; In the core assembly step, when the core rod is inserted into the first hole, it is simultaneously inserted into the connecting ring.

6. The method for manufacturing a core assembly according to claim 1, characterized in that: The cushion block is designed in accordance with the cantilever structure and the sand mold.

7. The method for manufacturing a core assembly according to claim 1, characterized in that: There are multiple cushion blocks.

8. The method for manufacturing a core assembly according to any one of claims 1 to 7, characterized in that: The size and material of the core rod are sufficient to support the torsional stress of the cantilever structure.

9. The method for manufacturing a core assembly according to claim 8, characterized in that: The core rod is made of cast iron.

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