Investment casting method for preventing deformation of thin-wall opening casting

Abstract

The invention relates to an investment casting method for preventing deformation of a thin-wall opening casting. The investment casting method for preventing the thin-wall opening casting from deforming comprises the steps that a mold is opened, mold compensation parameters are determined according to a three-dimensional model of the thin-wall opening casting and a three-dimensional model of a deformed wax piece, a wax piece mold is machined according to mold reference parameters and the mold compensation parameters, and the deformed wax piece is obtained by an original mold machined according to the mold reference parameters; wax injection is conducted, specifically, wax liquid is injected into the machined wax piece mold, and a wax mold is formed; grouping trees; making a shell; dewaxing is conducted; roasting is performed; smelting is conducted; casting is conducted; shell shaking is conducted, specifically, a shell shaking machine is used for shaking the outer side shell of the tree group casting to be broken and fall off; cutting and grinding; cleaning sand; classifying: classifying the thin-wall open castings into normal castings and abnormal castings; shaping is conducted, specifically, the abnormal casting is shaped through a shaping mold; and finally inspecting. According to the investment casting method for preventing the thin-wall opening casting from deforming, the appearance of a deformed wax mold can be greatly reduced, the casting shaping workload is reduced, and therefore the production efficiency of the thin-wall opening casting is improved.

Description

Technical Field

[0001] The invention relates to the technical field of investment casting, and in particular to an investment casting method for preventing deformation of thin-walled open castings. Background Art

[0002] Investment casting, also known as lost wax casting, is an ancient casting process that is widely used in modern industry. The basic principle is to use fusible materials (such as wax and plastic) to make a precise model, and then apply multiple layers of refractory coating on the surface of the model, which will form a shell after drying and hardening. Subsequently, the model is melted and flows out by heating, leaving an empty shell formed by the refractory material. Finally, the metal is melted and poured into the empty shell. After the metal cools, the refractory material is broken to obtain the final metal part.

[0003] In the related art, the investment casting process has many steps, and thin-walled open wax parts are very easy to deform during the investment casting process, causing the opening to become larger or smaller. The traditional processing technology requires all thin-walled open castings to be reshaped, and the thin-walled open castings are very easy to be damaged during the shaping process. The damaged castings need to be repaired through complicated processing processes, resulting in very low production efficiency of thin-walled open castings, which cannot meet production needs. Summary of the invention

[0004] Based on this, it is necessary to provide a method for preventing deformation of thin-walled open castings by investment casting, in order to address the problem that the traditional processing technology is very easy to damage the castings during shaping and cannot meet the customer's requirements.

[0005] An investment casting method for preventing deformation of thin-walled open castings, comprising: Opening the mold, determining the mold compensation parameters according to the three-dimensional model of the thin-walled open casting and the three-dimensional model of the deformed wax part, and processing the wax part mold according to the mold reference parameters and the mold compensation parameters, wherein the deformed wax part is obtained from the original mold processed according to the mold reference parameters; Wax injection, injecting wax liquid into the processed wax mold to form a wax model; Assemble trees, weld the wax pattern to the die head to form a tree group; Shell making, covering the surface of the tree group with refractory materials; Dewaxing, heating the refractory material to make the tree group melt and flow out to obtain the shell; Firing: heating the shell to high temperature to dry and solidify; Melting, melting steel into molten steel through casting equipment; Casting, pouring molten steel into the mold shell through the casting equipment to form a tree casting; Shell shaking: Use a shell shaking machine to break and remove the outer shell of the tree group casting; Grinding, cutting die heads in tree group castings, and grinding thin-walled open castings; Sand cleaning, clean the sticky sand remaining on the surface of thin-walled open castings; Classification: thin-walled open castings are divided into normal castings and abnormal castings according to their opening shapes; Shaping, using a shaping mold to shape the abnormal casting; Final inspection.

[0006] The above-mentioned investment casting method for preventing deformation of thin-walled open castings includes the processes of mold opening, wax injection, tree formation, shell making, dewaxing, roasting, smelting, casting, shell vibration, cutting, grinding, sand cleaning, classification, shaping and final inspection. In the mold opening process, the wax mold is optimized by processing the wax mold according to the mold reference parameters and the mold compensation parameters. The optimized wax mold pre-compensates the deformation of the wax mold, so that the wax mold formed after the wax injection process can meet the production needs without shaping, thereby realizing automated wax injection; after tree formation, shell making, dewaxing, roasting, smelting, casting, shell vibration, cutting, grinding, sand cleaning, classification and other processes, the proportion of normal castings can reach 80%, and the proportion of abnormal castings is only 20%; compared with the prior art that requires shaping of all thin-walled open castings in the shaping process, this method only needs to shape 20% of abnormal castings in the shaping process, which greatly reduces the workload of the shaping process, thereby improving the production efficiency of thin-walled open castings.

[0007] In one embodiment, determining the mold compensation parameters according to the three-dimensional model of the thin-walled open casting and the three-dimensional model of the deformed wax part includes: Determine the parameters of the reference model according to the three-dimensional model of the thin-walled open casting, and determine the parameters of the deformation model according to the three-dimensional model of the deformed wax part; Establishing a deformation prediction function according to the reference model parameters and the deformation model parameters; The mold compensation parameters are determined according to the reference model parameters and the deformation prediction function.

[0008] In one embodiment, the shaping mold includes an upper shaping part and a lower shaping part, and shaping the abnormal casting using the shaping mold includes: placing the abnormal casting at a preset position of the lower shaping portion; Controlling the upper shaping part to move downward by a preset distance to perform shaping and obtain a normal casting; Controlling the upper shaping part to reset; The ejection mechanism is controlled to eject the normal casting that has been completed.

[0009] In one embodiment, the upper shaping part includes an upper pull plate, a male clamping plate and an upper mold, the upper pull plate is fixedly connected to the male clamping plate, and the male clamping plate is connected to the upper mold via a first buffer spring; The male clamping plate is fixedly mounted with an inclined wedge, and the thickness of the inclined wedge increases uniformly from bottom to top. The upper die is provided with a hollow groove matching the inclined wedge, and oppositely arranged support blocks are mounted on both sides of the hollow groove. The inclined wedge is aligned with the center of the hollow groove and inserted between the oppositely arranged support blocks. The controlling the upper shaping part to move downward by a preset distance to perform shaping and obtain a normal casting comprises: Controlling the upper shaping part to move downward; When the upper mold contacts the lower shaping part and cannot move downward further, the upper pull plate and the male clamping plate are controlled to move downward further, so that the inclined wedge moves downward further relative to the support block, thereby moving the relatively arranged support blocks away from each other to perform shaping and obtain a normal casting.

[0010] In one embodiment, one side of the support block abuts against the upper die through an abutment spring, and the other side abuts against the inclined wedge.

[0011] In one embodiment, a spring hole matching the abutment spring is provided on one side of the support block, bosses are formed on both sides of the spring hole, and the upper mold is also equipped with a pressure block matching the boss, and the pressure block is used to prevent the support block from vertical displacement.

[0012] In one of the embodiments, a clamping block is formed at the upper end of the inclined wedge, and a clamping groove matching the clamping block is provided at the upper end of the male clamping plate.

[0013] In one embodiment, the lower shaping portion includes a bottom plate, a support block fixedly connected to the bottom plate, and a lower mold installed on the upper side of the support block; A push plate is provided between the bottom plate and the lower mold, the bottom plate and the push plate are connected via a second buffer spring, a product seat is fixedly mounted on the upper side of the push plate, the lower mold is provided with a through groove matching the product seat, and an ejection through hole is provided at the center of the bottom plate; The control ejection mechanism ejects the normal casting after shaping, including: The ejection mechanism is controlled to push the push plate upward through the ejection through hole, and then the product seat is driven by the push plate to move upward through the through slot to eject the normal casting that has been shaped.

[0014] In one of the embodiments, the upper end of the product seat is provided with a limiting structure that cooperates with the shaping of the casting.

[0015] In one of the embodiments, the upper end of the through groove is provided with a chamfered structure matching the product seat. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1A schematic flow chart of an investment casting method for preventing deformation of thin-walled open castings according to the present invention; Figure 2 It is a schematic structural diagram of a processed wax mold in the investment casting method for preventing deformation of thin-walled open castings of the present invention; Figure 3 It is a structural schematic diagram of a shaping mold in a closed state in an investment casting method for preventing deformation of a thin-walled open casting according to the present invention; Figure 4 It is a schematic structural diagram of a shaping mold in an open state in an investment casting method for preventing deformation of a thin-walled open casting according to the present invention; Figure 5 for Figure 4 Schematic diagram of the structure of the Zhonggong splint; Figure 6 for Figure 4 Schematic diagram of the structure of the middle wedge; Figure 7 for Figure 4 Schematic diagram of the structure of the middle support block; Figure 8 for Figure 4 Schematic diagram of the structure of the middle and lower molds; Fig. 9 for Figure 4 The structural diagram of the product seat; Fig.10 for Figure 4 Schematic diagram of the partial structure of the middle and upper plastic surgery part; Fig.11 for Figure 4 Schematic diagram of the structure of the middle and upper mold; Fig.12 for Figure 4 Schematic diagram of the structure of the midsole plate; Fig.13 for Figure 4 Structural schematic diagram of the middle and lower plastic part; Among them, 10 is an upper shaping part, 20 is a lower shaping part, 30 is a thin-walled open casting, 31 is an opening, 11 is an upper pull plate, 12 is a male clamping plate, 121 is a card slot, 13 is an upper mold, 131 is a hollow groove, 14 is a first buffer spring, 15 is an inclined wedge, 151 is a card block, 16 is a support block, 161 is a spring hole, 162 is a boss, 17 is an abutment spring, 18 is a pressure block, 21 is a bottom plate, 211 is an ejection through hole, 22 is a support block, 23 is a lower mold, 231 is a through slot, 24 is a push plate, 25 is a second buffer spring, 26 is a product seat, and 261 is a limiting structure. DETAILED DESCRIPTION

[0017] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present invention, so the present invention is not limited by the specific embodiments disclosed below.

[0018] It should be noted that when an element is referred to as being "fixed to" another element, it may be directly on the other element or there may also be a central 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 central element at the same time. In contrast, when an element is referred to as being "directly on" another element, there is no intermediate element. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only."

[0019] 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.

[0020] The invention discloses an investment casting method for preventing deformation of thin-walled open castings.

[0021] like Figure 1 As shown, the investment casting method for preventing deformation of thin-walled open castings includes: Opening the mold, determining the mold compensation parameters according to the three-dimensional model of the thin-walled open casting and the three-dimensional model of the deformed wax part, and processing the wax part mold according to the mold reference parameters and the mold compensation parameters, wherein the deformed wax part is obtained from the original mold processed according to the mold reference parameters; Wax injection, injecting wax liquid into the processed wax mold to form a wax model; Assemble trees, weld the wax pattern to the die head to form a tree group; Shell making, covering the surface of the tree group with refractory materials; Dewaxing, heating the refractory material to melt the tree group and get the shell; Firing: heating the shell to high temperature to dry and solidify; Melting, melting steel into molten steel through casting equipment; Casting, pouring molten steel into the mold shell through the casting equipment to form a tree casting; Shell shaking: Use a shell shaking machine to break and remove the outer shell of the tree group casting; Grinding, cutting die heads in tree group castings, and grinding thin-walled open castings; Sand cleaning, clean the sticky sand remaining on the surface of thin-walled open castings; Classification: thin-walled open castings are divided into normal castings and abnormal castings according to their opening shapes; Shaping, using a shaping mold to shape the abnormal casting; Final inspection.

[0022] The above-mentioned investment casting method for preventing deformation of thin-walled open castings includes the processes of mold opening, wax injection, tree formation, shell making, dewaxing, roasting, smelting, casting, shell vibration, cutting, grinding, sand cleaning, classification, shaping and final inspection. In the mold opening process, the wax mold is optimized by processing the wax mold according to the mold reference parameters and the mold compensation parameters. The optimized wax mold pre-compensates the deformation of the wax mold, so that the wax mold formed after the wax injection process can meet the production needs without shaping, thereby realizing automated wax injection; after tree formation, shell making, dewaxing, roasting, smelting, casting, shell vibration, cutting, grinding, sand cleaning, classification and other processes, the proportion of normal castings can reach 80%, and the proportion of abnormal castings is only 20%; compared with the prior art that requires shaping of all thin-walled open castings in the shaping process, this method only needs to shape 20% of abnormal castings in the shaping process, which greatly reduces the workload of the shaping process, thereby improving the production efficiency of thin-walled open castings.

[0023] Among them, determining the mold compensation parameters according to the three-dimensional model of the thin-walled open casting and the three-dimensional model of the deformed wax part includes: determining the reference model parameters according to the three-dimensional model of the thin-walled open casting, and determining the deformation model parameters according to the three-dimensional model of the deformed wax part; establishing a deformation prediction function according to the reference model parameters and the deformation model parameters; and determining the mold compensation parameters according to the reference model parameters and the deformation prediction function. Furthermore, multiple sets of reference model parameters and deformation model parameters can be first obtained, and the reference model parameters and deformation model parameters can be input into the artificial intelligence model for training to obtain the deformation prediction function, and the mold compensation parameters can be further determined according to the deformation prediction function and the reference model parameters, thereby improving the efficiency of determining the mold compensation parameters.

[0024] like Figures 2 to 13 As shown, the shaping mold includes an upper shaping part 10 and a lower shaping part 20. When the shaping mold is used to shape the abnormal casting, the abnormal casting is first placed at a preset position of the lower shaping part 20; then the upper shaping part 10 is controlled to move downward a preset distance to shape and obtain a normal casting; then the upper shaping part 10 is controlled to reset; finally, the ejection mechanism is controlled to eject the normal casting after shaping. Through the above steps, the shaping efficiency of abnormal castings can be greatly improved.

[0025] Furthermore, the upper shaping part 10 includes an upper pull plate 11, a male clamping plate 12 and an upper mold 13. The upper pull plate 11 is fixedly connected to the male clamping plate 12, and the male clamping plate 12 is connected to the upper mold 13 through a first buffer spring 14; the male clamping plate 12 is fixedly installed with an inclined wedge 15 and the inclined wedge 15 is vertically installed, and the upper mold 13 is provided with a hollow groove 131 that matches the inclined wedge 15, and oppositely arranged support blocks 16 are installed on both sides of the hollow groove 131, and the inclined wedge 15 is aligned with the center of the hollow groove 131 and inserted between the oppositely arranged support blocks 16.

[0026] When controlling the upper shaping part 10 to move downward a preset distance to perform shaping and obtain a normal casting, first control the upper shaping part 10 to move downward, and at this time the upper pull plate 11, the male clamping plate 12 and the upper mold 13 all move downward synchronously; when the upper mold 13 contacts the lower shaping part 20 and cannot continue to move downward, control the upper pull plate 11 and the male clamping plate 12 to continue to move downward, so that the inclined wedge 15 continues to move downward relative to the support block 16. Since the thickness of the inclined wedge 15 increases uniformly from bottom to top, during the downward movement of the inclined wedge 15 relative to the support block 16, the relatively arranged support blocks 16 can be moved away from each other. At this time, the lower ends of the support blocks 16 enter the openings 31 of the thin-walled open casting 30, and the relatively arranged support blocks 16 move away from each other so that the lower ends of the support blocks 16 can open the openings 31 of the thin-walled open casting 30, thereby performing shaping and obtaining a normal casting.

[0027] Furthermore, one side of the support block 16 abuts against the upper die 13 through the abutment spring 17, and the other side abuts against the wedge 15. When the wedge 15 moves downward relative to the support block 16, a horizontal thrust is generated on the support block 16, so that the abutment spring 17 is compressed. The abutment spring 17 can buffer the horizontal movement of the support block 16.

[0028] Furthermore, a spring hole 161 is provided on one side of the support block 16 to match the abutment spring 17, and bosses 162 are formed on both sides of the spring hole 161. The upper die 13 is also equipped with a pressing block 18 to match the bosses 162, and the pressing block 18 is used to prevent the support block 16 from vertical displacement. The spring hole 161 makes the connection between the support block 16 and the abutment spring 17 more secure. The pressing block 18 is fixedly mounted on the upper die 13 and is arranged above the bosses 162.

[0029] Furthermore, a block 151 is formed at the upper end of the angled wedge 15, and a slot 121 is provided at the upper end of the male clamping plate 12 to match the block 151. Through the cooperation between the block 151 and the slot 121, the angled wedge 15 is fixedly connected to the male clamping plate 12, so that the angled wedge 15 can always move synchronously with the upper pull plate 11 and the male clamping plate 12.

[0030] Among them, the lower shaping part 20 includes a bottom plate 21, a support block 22 fixedly connected to the bottom plate 21, and a lower mold 23 installed on the upper side of the support block 22; a push plate 24 is provided between the bottom plate 21 and the lower mold 23, the bottom plate 21 and the push plate 24 are connected by a second buffer spring 25, a product seat 26 is fixedly installed on the upper side of the push plate 24, the lower mold 23 is provided with a through groove 231 matching the product seat 26, and an ejection through hole 211 is provided in the center of the bottom plate 21.

[0031] When the upper shaping part 10 is controlled to move downward a preset distance to perform shaping and obtain a normal casting, the support block 16 exerts a downward force on the thin-walled open casting 30, and this force is applied to the push plate 24 through the product seat 26, so that the second buffer spring 25 is compressed; in the process of controlling the upper shaping part 10 to reset, the support block 16 no longer exerts a downward force on the thin-walled open casting 30, so that the second buffer spring 25 is reset.

[0032] When the ejection mechanism is controlled to eject the normal casting that has been shaped, the ejection mechanism is first controlled to push the push plate 24 upward through the ejection through hole 211, and then the product seat 26 is driven to move upward through the through slot 231 by the push plate 24 to eject the normal casting that has been shaped. Through the mutual cooperation of the ejection mechanism, the ejection through hole 211, the push plate 24, the product seat 26, and the through slot 231, the normal casting that has been shaped can be easily taken away, and it is also convenient to place the abnormal casting on the product seat 26 to repeat the shaping process. In the process of controlling the ejection mechanism to eject the normal casting that has been shaped, the push plate 24 is subjected to the upward force of the ejection mechanism, and the bottom plate 21 is fixed. At this time, the second buffer spring 25 is stretched by force. After the ejection mechanism is reset, the second buffer spring 25 is reset.

[0033] Furthermore, a limiting structure 261 for cooperating with the casting shaping is provided at the upper end of the product seat 26. The limiting structure 261 can limit the thin-walled open casting on the product seat 26 to prevent the thin-walled open casting from being displaced during the shaping process, thereby improving the shaping quality.

[0034] Furthermore, the upper end of the through groove 231 is provided with a chamfer structure that matches the product seat 26. Through the chamfer structure, during the operation of the shaping mold, the rigid collision between the product seat 26 and the upper end of the through groove 231 can be reduced, thereby reducing the wear of the product seat 26 and the lower mold 23.

[0035] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0036] 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. An investment casting method for preventing deformation of thin-walled open castings, characterized in that: include: Opening the mold, determining the mold compensation parameters according to the three-dimensional model of the thin-walled open casting and the three-dimensional model of the deformed wax part, and processing the wax part mold according to the mold reference parameters and the mold compensation parameters, wherein the deformed wax part is obtained from the original mold processed according to the mold reference parameters; Wax injection, injecting wax liquid into the processed wax mold to form a wax model; Assemble trees, weld the wax pattern to the die head to form a tree group; Shell making, covering the surface of the tree group with refractory materials; Dewaxing, heating the refractory material to melt the tree group and get the shell; Firing: heating the shell to high temperature to dry and solidify; Melting, melting steel into molten steel through casting equipment; Casting, pouring molten steel into the mold shell through the casting equipment to form a tree casting; Shell shaking: Use a shell shaking machine to break and remove the outer shell of the tree group casting; Grinding, cutting die heads in tree group castings, and grinding thin-walled open castings; Sand cleaning, clean the sticky sand remaining on the surface of thin-walled open castings; Classification: thin-walled open castings are divided into normal castings and abnormal castings according to their opening shapes; Shaping, using a shaping mold to shape the abnormal casting; Final inspection.

2. The method according to claim 1, characterized in that Determining the mold compensation parameters according to the three-dimensional model of the thin-walled open casting and the three-dimensional model of the deformed wax part includes: Determine the parameters of the reference model according to the three-dimensional model of the thin-walled open casting, and determine the parameters of the deformation model according to the three-dimensional model of the deformed wax part; Establishing a deformation prediction function according to the reference model parameters and the deformation model parameters; The mold compensation parameters are determined according to the reference model parameters and the deformation prediction function.

3. The method according to claim 1 or 2, characterized in that: The shaping mold comprises an upper shaping part and a lower shaping part, and shaping the abnormal casting by using the shaping mold comprises: placing the abnormal casting at a preset position of the lower shaping portion; Controlling the upper shaping part to move downward by a preset distance to perform shaping and obtain a normal casting; Controlling the upper shaping part to reset; The ejection mechanism is controlled to eject the normal castings that have been shaped.

4. The method according to claim 3, characterized in that The upper shaping part comprises an upper pull plate, a male clamping plate and an upper die, the upper pull plate is fixedly connected to the male clamping plate, and the male clamping plate is connected to the upper die via a first buffer spring; The male clamping plate is fixedly mounted with an inclined wedge, and the thickness of the inclined wedge increases uniformly from bottom to top. The upper die is provided with a hollow groove matching the inclined wedge, and oppositely arranged support blocks are mounted on both sides of the hollow groove. The inclined wedge is aligned with the center of the hollow groove and inserted between the oppositely arranged support blocks. The controlling the upper shaping part to move downward by a preset distance to perform shaping and obtain a normal casting comprises: Controlling the upper shaping part to move downward; When the upper mold contacts the lower shaping part and cannot move downward further, the upper pull plate and the male clamping plate are controlled to move downward further, so that the inclined wedge moves downward further relative to the support block, thereby moving the relatively arranged support blocks away from each other to perform shaping and obtain a normal casting.

5. The method according to claim 4, characterized in that One side of the support block abuts against the upper die through an abutment spring, and the other side abuts against the inclined wedge.

6. The method according to claim 5, characterized in that A spring hole matching the abutment spring is provided on one side of the support block, bosses are formed on both sides of the spring hole, and a pressure block matching the bosses is also installed on the upper mold, and the pressure block is used to prevent the support block from being displaced in the vertical direction.

7. The method according to claim 6, characterized in that A clamping block is formed at the upper end of the inclined wedge, and a clamping groove matching the clamping block is provided at the upper end of the male clamping plate.

8. The method according to claim 3, characterized in that The lower shaping part includes a bottom plate, a support block fixedly connected to the bottom plate, and a lower mold installed on the upper side of the support block; A push plate is provided between the bottom plate and the lower mold, the bottom plate and the push plate are connected via a second buffer spring, a product seat is fixedly mounted on the upper side of the push plate, the lower mold is provided with a through groove matching the product seat, and an ejection through hole is provided at the center of the bottom plate; The control ejection mechanism ejects the normal casting after shaping, including: The ejection mechanism is controlled to push the push plate upward through the ejection through hole, and then the product seat is driven by the push plate to move upward through the through slot to eject the normal casting that has been shaped.

9. The method according to claim 8, characterized in that The upper end of the product seat is provided with a limiting structure that cooperates with the shaping of the casting.

10. The method according to claim 9, characterized in that The upper end of the through groove is provided with a chamfered structure matching the product seat.

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