Size control method for large complex thin-wall structural casting

Abstract

The invention provides a size control method for a large complex thin-wall structural casting, which comprises the following steps: S1, setting the shrinkage rate of a grinding tool, designing a precision investment casting mold, and S2, injecting a wax material into the precision investment casting mold to obtain a wax mold; s3, the wax mold is connected with an inner sprue and a pouring gate together, and a wax tree is obtained; s4, the wax tree is subjected to slurry dipping, sand spraying and drying layer by layer, and a mold shell is obtained; s5, dewaxing the mold shell to obtain a mold shell; s6, the mold shell is sintered, then high-temperature metal is poured into the mold shell, the mold shell is removed, a pouring gate and a pouring gate are cut, and a casting is obtained; and S7, the size of the casting is determined through a testing fixture, and the casting is obtained after the casting is qualified. According to the size control method for the large complex thin-wall structural casting, the size of the casting can be effectively detected, whether the size is qualified or not can be quickly determined, it is ensured that the result can be matched with a CMM detection result, the working efficiency is improved, and the production cycle and cost are reduced.

Description

Technical Field

[0001] The invention relates to the technical field of aviation precision casting, in particular to a method for controlling the size of a large complex thin-walled structure casting. Background Art

[0002] Investment castings have the characteristics of high dimensional accuracy, flexible and complex structural design, and are widely used in aircraft. Generally, the design margin of aviation precision castings is very small, and the dimensional accuracy requirements are very high. Castings require 100% CMM inspection or scanning to ensure that the product size is qualified. However, since complex castings will inevitably deform and shrink during the production process, the dimensional control of investment castings becomes more difficult. Often, a shaping process is required after casting to ensure the size. The dimensional control and guarantee of complex castings are very challenging, which restricts the mass production of such complex castings. After shaping, a reasonable and effective control method is required to ensure dimensional control. Otherwise, the shaping + CMM inspection solution will affect efficiency too much and increase the product manufacturing cycle and cost. Summary of the invention

[0003] The purpose of the present invention is to overcome and supplement the deficiencies in the prior art and to provide a method for controlling the dimensions of large, complex, thin-walled structure castings, so that the casting dimensions can be effectively detected, the dimensions can be quickly confirmed to be qualified, and the results can be ensured to be consistent with the CMM detection results, thereby improving work efficiency and reducing production cycles and costs.

[0004] The technical solution adopted by the present invention is: A method for controlling the size of a large complex thin-walled structure casting, comprising the following steps: Step S1. Setting the mold shrinkage rate, and designing an integrated investment casting mold according to the mold shrinkage rate; Step S2. Inject the wax material into the investment casting mold, hold the pressure for 50-80 seconds, and then open the mold to obtain a wax mold; Step S3. Connect the wax mold, the ingates and the runners together to obtain a wax tree; Step S4. Dipping the wax tree layer by layer with slurry, pouring sand and drying it to obtain a mold shell; Step S5. removing the wax from the mold shell to obtain a mold shell with a mold cavity; Step S6. Sintering the shell, then pouring the high-temperature metal into the shell, removing the shell after cooling, cutting the runner and gate, and obtaining the casting; Step S7. The casting is passed through a checking fixture to confirm the casting size, and the casting is obtained after it passes the inspection.

[0005] Preferably, the method for controlling the size of large complex thin-walled structural castings is as follows: in step S1, the investment casting mold includes a lower mold and an upper mold arranged above the lower mold, the lower mold includes a lower mold plate, a side plate assembly is arranged on the outer periphery of the lower mold plate, the lower mold, the upper mold and the side plate assembly are combined to form a mold cavity, a first movable block assembly is arranged on the side of the side plate assembly close to the cavity, a first groove and a second groove are arranged on the lower mold, a second movable block assembly is arranged in the first groove, and a third movable block assembly is arranged in the second groove.

[0006] Preferably, the method for controlling the size of a large complex thin-walled structural casting is described, wherein: the side panel assembly includes a first side panel and a second side panel, the first side panel is arranged on the left and right sides of the lower mold, and the second side panel is arranged on the upper and lower sides of the lower mold; the first movable block assembly includes a first movable block, a second movable block and a third movable block, the first movable block is arranged on both sides of the upper side of the lower mold, the second movable block is arranged on the inner side of the first side panel, and the third movable block is arranged on the inner side of the second side panel located on the lower side.

[0007] Preferably, the size control method of the large complex thin-walled structural casting is as follows: the second movable block assembly includes a fourth movable block, a fifth movable block, a sixth movable block and a seventh movable block, the fifth movable block is arranged in the middle of the first groove, the sixth movable block is arranged around the fifth movable block, the seventh movable block is arranged in the gap between two adjacent sixth movable blocks, the fourth movable block is arranged on the top of the third movable block assembly, the third movable block assembly includes an eighth movable block, a ninth movable block, a tenth movable block and an eleventh movable block, the eighth movable block is arranged in the middle of the second groove, the ninth movable block and the tenth movable block are respectively arranged in the second grooves on both sides of the eighth movable block, and the eleventh movable block is arranged in the gap of the second groove between the ninth movable block and the tenth movable block.

[0008] Preferably, the size control method of the large complex thin-walled structure casting is as follows: in step S3, the wax tree includes a side runner, a main runner is arranged at the bottom of the side runner, the side runner and the main runner are connected, a pouring cup is arranged in the middle of the bottom of the main runner, a plurality of inner gates are arranged around the top of the side runner, and the other end of the inner gate is connected to the wax mold.

[0009] Preferably, in the method for controlling the size of a large complex thin-walled structure casting, step S4 is specifically as follows: S41. The wax material is immersed in the surface slurry, and the slurry is dried to obtain a wax material; S42. The wax material is immersed in the backing slurry, and the slurry is dried to obtain a wax material II; S43. Repeat step S2 seven times to obtain a mold shell.

[0010] Preferably, in the method for controlling the size of large complex thin-walled structural castings, the surface layer slurry in step S41 comprises silica sol and zircon powder, the weight ratio of the silica sol and zircon powder is (2 - 2.5):(10-10.5), and the viscosity of the surface layer slurry is 35-45 S; in step S42, the back layer slurry comprises silica sol and mullite powder in a mass ratio of 1:(1.4-1.5), and the viscosity of the back layer slurry is 15-25S.

[0011] Preferably, in the method for controlling the size of large complex thin-walled structure castings, the temperature for removing the wax in step S5 is 170-180°C and the pressure is 0.8-1Mpa; the sintering temperature in step S6 is 1100-1200°C and the sintering time is 3-3.5h.

[0012] Preferably, the size control method of the large complex thin-walled structure casting is as follows: in step S7, the inspection tool includes a base plate, a first baffle is arranged on one side of the base plate, a inspection tool is symmetrically arranged on one side of the first baffle, a handle is symmetrically arranged on the other side of the first baffle, a support plate is arranged on the other side of the base plate, a first pressure clamp is arranged on the support plate, a first slide groove is arranged on the base plate between the first baffle plate and the support plate, a first movable block and a second movable block are slidably arranged on the first slide groove, a spring is arranged between the first movable block and the second movable block, an inlay is connected in the middle of the spring, a Y-shaped pressure block is arranged on the base plate, a support block is arranged on the side of the base plate close to the inlay, a second pressure clamp is arranged on the support block, and the ends of the second pressure clamp away from the support block are respectively connected to the inlay and the Y-shaped pressure block, a limiting block is arranged in the middle of the Y-shaped pressure block, second baffles are arranged on the outer sides of the first movable block and the second movable block, a positioning pin is arranged on the second baffle, a second slide groove is arranged on the side of the base plate close to the support plate, and a screw is slidably arranged on the first slide groove.

[0013] Preferably, in the method for controlling the size of large complex thin-walled structural castings, support pins are arranged between the two ends of the Y-shape of the Y-shaped pressing block and the bottom plate, and a positioning piece is arranged on a side of the first baffle plate close to the Y-shaped pressing block.

[0014] Advantages of the present invention: The dimension control method of large complex thin-walled structure castings of the present invention can effectively detect the casting dimensions, quickly confirm whether the dimensions are qualified, ensure that the results are consistent with the CMM detection results, improve work efficiency, and reduce production cycle and cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of the structure of the investment casting mold of the present invention.

[0016] Figure 2It is a schematic diagram of the structure of the side plate assembly arranged on the periphery of the lower template of the present invention.

[0017] Figure 3 The present invention is a schematic structural diagram of a first movable block assembly disposed on a side of the side plate assembly close to the cavity.

[0018] Figure 4 It is a schematic structural diagram of a second movable block assembly provided on the lower mold of the present invention.

[0019] Figure 5 It is a structural schematic diagram of a third movable block assembly provided on the lower mold of the present invention.

[0020] Figure 6 It is a structural schematic diagram of a wax tree of the present invention.

[0021] Figure 7 It is a three-dimensional diagram of the inspection tool of the present invention.

[0022] Figure 8 It is a cross-sectional view of the inspection tool of the present invention.

[0023] Fig. 9 It is a top view of the inspection tool of the present invention.

[0024] Fig.10 It is a schematic structural diagram of the casting of the present invention.

[0025] Fig.11 It is a bottom view of the casting of the present invention.

[0026] Fig.12 This is a schematic diagram of the structure in which the casting is placed on a gauge for inspection. DETAILED DESCRIPTION

[0027] The present invention will be further described below in conjunction with specific drawings and embodiments.

[0028] Example 1 A method for controlling the size of a large complex thin-walled structure casting, comprising the following steps: Step S1. Setting the mold shrinkage rate, and designing an integrated investment casting mold according to the mold shrinkage rate; like Figure 1-Figure 6 In step S1, the investment casting mold includes a lower mold 1 and an upper mold 2 arranged above the lower mold 1, the lower mold 1 includes a lower mold plate 11, and a side plate assembly is arranged on the outer periphery of the lower mold plate 11. The lower mold 1, the upper mold 2 and the side plate assembly are combined to form a mold cavity, and a first movable block assembly is arranged on a side of the side plate assembly close to the cavity. A first groove and a second groove are arranged on the lower mold 1, a second movable block assembly is arranged in the first groove, and a third movable block assembly is arranged in the second groove.

[0029] The side panel assembly includes a first side panel 3 and a second side panel 4, wherein the first side panel 3 is arranged on the left and right sides of the lower mold 1, and the second side panel 4 is arranged on the upper and lower sides of the lower mold 1; the first movable block assembly includes a first movable block 5, a second movable block 6 and a third movable block 7, wherein the first movable block 5 is arranged on both sides of the upper side of the lower mold 1, the second movable block 6 is arranged on the inner side of the first side panel 3, and the third movable block 7 is arranged on the inner side of the second side panel 4 located on the lower side.

[0030] The second movable block assembly includes a fourth movable block 8, a fifth movable block 9, a sixth movable block 10 and a seventh movable block 12. The fifth movable block 9 is arranged in the middle of the first groove, the sixth movable block 10 is arranged around the fifth movable block 9, and the seventh movable block 12 is arranged in the gap between two adjacent sixth movable blocks 10. The fourth movable block 8 is arranged on the top of the third movable block assembly. The third movable block assembly includes an eighth movable block 13, a ninth movable block 14, a tenth movable block 15 and an eleventh movable block 16. The eighth movable block 13 is arranged in the middle of the second groove, the ninth movable block 14 and the tenth movable block 15 are respectively arranged in the second grooves on both sides of the eighth movable block 13, and the eleventh movable block 16 is arranged in the gap of the second groove between the ninth movable block 14 and the tenth movable block 15.

[0031] Step S2. Inject the wax material into the investment casting mold, hold the pressure for 50 seconds, and then open the mold to obtain a wax mold; Step S3. Connect the wax mold, the inner gate and the runner together to obtain a wax tree; Figure 6 The wax tree includes a side runner 17, a main runner 18 is arranged at the bottom of the side runner 17, the side runner 17 is connected to the main runner 18, a pouring cup 19 is arranged in the middle of the bottom of the main runner 18, a plurality of inner gates 20 are arranged around the top of the side runner 17, and the other end of the inner gate 20 is connected to the wax mold 21; The specific production method of step S3 is as follows: after the size of the above-mentioned wax model is stable, first, a specific inner gate 20 is adhered to the melted wax liquid and connected to the set position of the wax model. After the wax model and the inner gate are spliced ​​and adhered, the side runner is adhered with wax liquid to splice the main runner. Finally, the spliced ​​wax model and the inner gate and the side runner and the main runner are coated with wax liquid to adhere them. After cooling and fixing, a special wax tree is obtained.

[0032] Step S4. Dipping the wax tree layer by layer with slurry, pouring sand and drying it to obtain a mold shell; Step S4 is specifically as follows: S41. The wax material is immersed in the surface slurry, and the slurry is dried to obtain a wax material; In step S41, the surface layer slurry includes silica sol and zircon powder, the weight ratio of the silica sol and zircon powder is 2:10, and the viscosity of the surface layer slurry is 35S; in step S42, the back layer slurry includes silica sol and mullite powder, the weight ratio is 1:1.4, and the viscosity of the back layer slurry is 15S; S42. The wax material is immersed in the backing slurry, and the slurry is dried to obtain a wax material II; S43. Repeat step S2 seven times to obtain a mold shell; Step S5. Dewaxing the mold shell at a temperature of 170°C and a pressure of 0.8 MPa to obtain a mold shell with a mold cavity; Step S6. Sintering the shell at a sintering temperature of 1100°C for 3.5 hours, then pouring the high-temperature metal into the shell, removing the shell after cooling, cutting the runner and gate, and obtaining a casting; Step S7. The casting is passed through a checking fixture to confirm the casting size, and the casting is obtained after it passes the inspection.

[0033] like Figure 7-Figure 9 The inspection tool comprises a bottom plate 22, a first baffle 23 is arranged on one side of the bottom plate 22, a inspection tool 24 is symmetrically arranged on one side of the first baffle 23, a handle 25 is symmetrically arranged on the other side of the first baffle 23, a support plate 26 is arranged on the other side of the bottom plate 22, a first pressing clamp 27 is arranged on the support plate 26, a first slide groove 39 is arranged on the bottom plate 22 between the first baffle 23 and the support plate 26, a first movable block 28 and a second movable block 29 are slidably arranged on the first slide groove 39, a spring 30 is arranged between the first movable block 28 and the second movable block 29, an insert 31 is connected in the middle of the spring 30, a Y-shaped pressing block 32 is arranged on the bottom plate 22, and the bottom plate 22 is close to the insert 3 A support block 33 is provided on one side of the bottom plate 22, a second pressure clamp 34 is provided on the support block 32, and the ends of the second pressure clamp 34 away from the support block 33 are respectively connected to the insert 31 and the Y-shaped pressure block 32, a limit block 35 is provided in the middle of the Y-shaped pressure block 32, second baffles 36 are provided on the outer sides of the first movable block 28 and the second movable block 29, and a positioning pin 37 is provided on the second baffle 36, a second slide groove 40 is provided on the side of the bottom plate 22 close to the support plate 26, and a screw 38 is slidably provided on the first slide groove; support pins 41 are provided between the Y-shaped ends of the Y-shaped pressure block 32 and the bottom plate 22, and a positioning piece 42 is provided on a side of the first baffle 23 close to the Y-shaped pressure block 32.

[0034] Fig.10 The structural diagram of the casting is shown in Figure 2. Fig.11 is a bottom view of the casting of the present invention, Fig.12 This is a schematic diagram of the structure in which the casting is placed on a gauge for inspection.

[0035] The operation method of the inspection tool is as follows: first, the casting 43 is placed on the support plate 26, and then the casting 43 is placed against the positioning piece 42, the positioning pin 37 is synchronously closed to clamp the casting 43, and then the casting is pressed by the first pressing clamp 27, and then the Y-shaped pressing block 32 is placed on the casting 43 and pressed by the second pressing clamp 34. After the fixing of the casting 43 is completed, the inspection tool 24 of the go / no-go gauge measuring tool is used to measure and record the casting 43, and quickly verify whether the size of the feature of the casting 43 relative to the reference is correct, and the operation is very convenient.

[0036] Example 2 A method for controlling the size of a large complex thin-walled structure casting, comprising the following steps: Step S1. Setting the mold shrinkage rate, and designing an integrated investment casting mold according to the mold shrinkage rate; like Figure 1-Figure 6 In step S1, the investment casting mold includes a lower mold 1 and an upper mold 2 arranged above the lower mold 1, the lower mold 1 includes a lower mold plate 11, and a side plate assembly is arranged on the outer periphery of the lower mold plate 11. The lower mold 1, the upper mold 2 and the side plate assembly are combined to form a mold cavity, and a first movable block assembly is arranged on a side of the side plate assembly close to the cavity. A first groove and a second groove are arranged on the lower mold 1, a second movable block assembly is arranged in the first groove, and a third movable block assembly is arranged in the second groove.

[0037] The side panel assembly includes a first side panel 3 and a second side panel 4, wherein the first side panel 3 is arranged on the left and right sides of the lower mold 1, and the second side panel 4 is arranged on the upper and lower sides of the lower mold 1; the first movable block assembly includes a first movable block 5, a second movable block 6 and a third movable block 7, wherein the first movable block 5 is arranged on both sides of the upper side of the lower mold 1, the second movable block 6 is arranged on the inner side of the first side panel 3, and the third movable block 7 is arranged on the inner side of the second side panel 4 located on the lower side.

[0038] The second movable block assembly includes a fourth movable block 8, a fifth movable block 9, a sixth movable block 10 and a seventh movable block 12. The fifth movable block 9 is arranged in the middle of the first groove, the sixth movable block 10 is arranged around the fifth movable block 9, and the seventh movable block 12 is arranged in the gap between two adjacent sixth movable blocks 10. The fourth movable block 8 is arranged on the top of the third movable block assembly. The third movable block assembly includes an eighth movable block 13, a ninth movable block 14, a tenth movable block 15 and an eleventh movable block 16. The eighth movable block 13 is arranged in the middle of the second groove, the ninth movable block 14 and the tenth movable block 15 are respectively arranged in the second grooves on both sides of the eighth movable block 13, and the eleventh movable block 16 is arranged in the gap of the second groove between the ninth movable block 14 and the tenth movable block 15.

[0039] Investment casting mold assembly method: S11. Figure 5First, put the lower template 11 in place, and place two ninth movable blocks 14, two tenth movable blocks 15, and four eleventh movable blocks 16 respectively in the first groove positions of the lower template 11, and then place the eighth movable block 13 in the center position, and limit the third movable block assembly; S12. Fix the movable block above the lower template 11 in the same manner, such as Figure 4 First, place four seventh movable blocks 12 and four sixth movable blocks 10 in the second groove of the movable block of the lower template 11, then place the fifth movable block 9 in the center, limit the third movable block assembly, and then place the fourth movable block 8 on the eighth movable block 13, the ninth movable block 14, the tenth movable block 15 and the eleventh movable block 16 to complete the assembly of the inner cavity movable block; S13. After the inner cavity pieces are assembled, the outer ring pieces are assembled. Figure 3 , respectively splice two first movable blocks 5, two second movable blocks 6 and one third movable block 7 at the periphery of the inner cavity movable block according to the position in the figure, so that the inner movable block and the outer movable block can form an integral cavity movable block; S14. After the cavity is spliced, the next step is to splice the outer side panels, place the first side panel 3 and the second side panel 4 in the outer groove of the lower template 11, limit the cavity block, and finally cover the upper cover plate 2 to complete the assembly of the investment casting mold; Step S2. Inject the wax material into the investment casting mold, hold the pressure for 60 seconds, and then open the mold to obtain a wax mold; Step S3. Connect the wax mold, the inner gate and the runner together to obtain a wax tree; Figure 6 The wax tree includes a side runner 17, a main runner 18 is arranged at the bottom of the side runner 17, the side runner 17 is connected to the main runner 18, a pouring cup 19 is arranged in the middle of the bottom of the main runner 18, a plurality of inner gates 20 are arranged around the top of the side runner 17, and the other end of the inner gate 20 is connected to the wax mold 21; Step S4. Dipping the wax tree layer by layer with slurry, pouring sand and drying it to obtain a mold shell; Step S4 is specifically as follows: S41. The wax material is immersed in the surface slurry, and the slurry is dried to obtain a wax material; In step S41, the surface layer slurry includes silica sol and zircon powder, the weight ratio of the silica sol and zircon powder is 2.2:10, and the viscosity of the surface layer slurry is 40S; in step S42, the back layer slurry includes silica sol and mullite powder, the weight ratio is 1:1.45, and the viscosity of the back layer slurry is 20S; S42. The wax material is immersed in the backing slurry, and the slurry is dried to obtain a wax material II; S43. Repeat step S2 seven times to obtain a mold shell; Step S5. Dewaxing the mold shell at a temperature of 175°C and a pressure of 0.9 MPa to obtain a mold shell with a mold cavity; Step S6. Sinter the shell at a sintering temperature of 1150°C for 3 hours, then pour the high-temperature metal into the shell, remove the shell after cooling, cut the runner and gate, and obtain the casting; Step S7. The casting is passed through a checking fixture to confirm the casting size, and the casting is obtained after it passes the inspection.

[0040] like Figure 7-Figure 9 The inspection tool comprises a bottom plate 22, a first baffle 23 is arranged on one side of the bottom plate 22, a inspection tool 24 is symmetrically arranged on one side of the first baffle 23, a handle 25 is symmetrically arranged on the other side of the first baffle 23, a support plate 26 is arranged on the other side of the bottom plate 22, a first pressing clamp 27 is arranged on the support plate 26, a first slide groove 39 is arranged on the bottom plate 22 between the first baffle 23 and the support plate 26, a first movable block 28 and a second movable block 29 are slidably arranged on the first slide groove 39, a spring 30 is arranged between the first movable block 28 and the second movable block 29, an insert 31 is connected in the middle of the spring 30, a Y-shaped pressing block 32 is arranged on the bottom plate 22, and the bottom plate 22 is close to the insert 3 A support block 33 is provided on one side of the bottom plate 22, a second pressure clamp 34 is provided on the support block 32, and the ends of the second pressure clamp 34 away from the support block 33 are respectively connected to the insert 31 and the Y-shaped pressure block 32, a limit block 35 is provided in the middle of the Y-shaped pressure block 32, second baffles 36 are provided on the outer sides of the first movable block 28 and the second movable block 29, and a positioning pin 37 is provided on the second baffle 36, a second slide groove 40 is provided on the side of the bottom plate 22 close to the support plate 26, and a screw 38 is slidably provided on the first slide groove; support pins 41 are provided between the Y-shaped ends of the Y-shaped pressure block 32 and the bottom plate 22, and a positioning piece 42 is provided on a side of the first baffle 23 close to the Y-shaped pressure block 32.

[0041] The operation method of the inspection tool is as follows: first, the casting 43 is placed on the support plate 26, and then the casting 43 is placed against the positioning piece 42, the positioning pin 37 is synchronously closed to clamp the casting 43, and then the casting is pressed by the first pressing clamp 27, and then the Y-shaped pressing block 32 is placed on the casting 43 and pressed by the second pressing clamp 34. After the fixing of the casting 43 is completed, the inspection tool 24 of the go / no-go gauge measuring tool is used to measure and record the casting 43, and quickly verify whether the size of the feature of the casting 43 relative to the reference is correct, and the operation is very convenient.

[0042] Example 3 A method for controlling the size of a large complex thin-walled structure casting, comprising the following steps: Step S1. Setting the mold shrinkage rate, and designing an integrated investment casting mold according to the mold shrinkage rate; like Figure 1-Figure 6 In step S1, the investment casting mold includes a lower mold 1 and an upper mold 2 arranged above the lower mold 1, the lower mold 1 includes a lower mold plate 11, and a side plate assembly is arranged on the outer periphery of the lower mold plate 11. The lower mold 1, the upper mold 2 and the side plate assembly are combined to form a mold cavity, and a first movable block assembly is arranged on a side of the side plate assembly close to the cavity. A first groove and a second groove are arranged on the lower mold 1, a second movable block assembly is arranged in the first groove, and a third movable block assembly is arranged in the second groove.

[0043] The side panel assembly includes a first side panel 3 and a second side panel 4, wherein the first side panel 3 is arranged on the left and right sides of the lower mold 1, and the second side panel 4 is arranged on the upper and lower sides of the lower mold 1; the first movable block assembly includes a first movable block 5, a second movable block 6 and a third movable block 7, wherein the first movable block 5 is arranged on both sides of the upper side of the lower mold 1, the second movable block 6 is arranged on the inner side of the first side panel 3, and the third movable block 7 is arranged on the inner side of the second side panel 4 located on the lower side.

[0044] The second movable block assembly includes a fourth movable block 8, a fifth movable block 9, a sixth movable block 10 and a seventh movable block 12. The fifth movable block 9 is arranged in the middle of the first groove, the sixth movable block 10 is arranged around the fifth movable block 9, and the seventh movable block 12 is arranged in the gap between two adjacent sixth movable blocks 10. The fourth movable block 8 is arranged on the top of the third movable block assembly. The third movable block assembly includes an eighth movable block 13, a ninth movable block 14, a tenth movable block 15 and an eleventh movable block 16. The eighth movable block 13 is arranged in the middle of the second groove, the ninth movable block 14 and the tenth movable block 15 are respectively arranged in the second grooves on both sides of the eighth movable block 13, and the eleventh movable block 16 is arranged in the gap of the second groove between the ninth movable block 14 and the tenth movable block 15.

[0045] Step S2. Inject the wax material into the investment casting mold, hold the pressure for 80 seconds, and then open the mold to obtain a wax mold; Step S3. Connect the wax mold, the inner gate and the runner together to obtain a wax tree; Figure 6 The wax tree includes a side runner 17, a main runner 18 is arranged at the bottom of the side runner 17, the side runner 17 is connected to the main runner 18, a pouring cup 19 is arranged in the middle of the bottom of the main runner 18, a plurality of inner gates 20 are arranged around the top of the side runner 17, and the other end of the inner gate 20 is connected to the wax mold 21.

[0046] Step S4. Dipping the wax tree layer by layer with slurry, pouring sand and drying it to obtain a mold shell; Step S4 is specifically as follows: S41. The wax material is immersed in the surface slurry, and the slurry is dried to obtain a wax material; In step S41, the surface layer slurry includes silica sol and zircon powder, the weight ratio of the silica sol and zircon powder is 2.5:10.5, and the viscosity of the surface layer slurry is 45S; in step S42, the back layer slurry includes silica sol and mullite powder, the weight ratio is 1:1.5, and the viscosity of the back layer slurry is 25S; S42. The wax material is immersed in the backing slurry, and the slurry is dried to obtain a wax material II; S43. Repeat step S2 seven times to obtain a mold shell; Step S5. Dewaxing the mold shell at a temperature of 180°C and a pressure of 1 MPa to obtain a mold shell with a mold cavity; Step S6. Sintering the shell at a sintering temperature of 1200°C for 3 hours, then pouring the high-temperature metal into the shell, removing the shell after cooling, cutting the runner and gate, and obtaining a casting; Step S7. The casting is passed through a checking fixture to confirm the casting size, and the casting is obtained after it passes the inspection.

[0047] like Figure 7-Figure 9 The inspection tool comprises a bottom plate 22, a first baffle 23 is arranged on one side of the bottom plate 22, a inspection tool 24 is symmetrically arranged on one side of the first baffle 23, a handle 25 is symmetrically arranged on the other side of the first baffle 23, a support plate 26 is arranged on the other side of the bottom plate 22, a first pressing clamp 27 is arranged on the support plate 26, a first slide groove 39 is arranged on the bottom plate 22 between the first baffle 23 and the support plate 26, a first movable block 28 and a second movable block 29 are slidably arranged on the first slide groove 39, a spring 30 is arranged between the first movable block 28 and the second movable block 29, an insert 31 is connected in the middle of the spring 30, a Y-shaped pressing block 32 is arranged on the bottom plate 22, and the bottom plate 22 is close to the insert 3 A support block 33 is provided on one side of the bottom plate 22, a second pressure clamp 34 is provided on the support block 32, and the ends of the second pressure clamp 34 away from the support block 33 are respectively connected to the insert 31 and the Y-shaped pressure block 32, a limit block 35 is provided in the middle of the Y-shaped pressure block 32, second baffles 36 are provided on the outer sides of the first movable block 28 and the second movable block 29, and a positioning pin 37 is provided on the second baffle 36, a second slide groove 40 is provided on the side of the bottom plate 22 close to the support plate 26, and a screw 38 is slidably provided on the first slide groove; support pins 41 are provided between the Y-shaped ends of the Y-shaped pressure block 32 and the bottom plate 22, and a positioning piece 42 is provided on a side of the first baffle 23 close to the Y-shaped pressure block 32.

[0048] The operation method of the inspection tool is as follows: first, the casting 43 is placed on the support plate 26, and then the casting 43 is placed against the positioning piece 42, the positioning pin 37 is synchronously closed to clamp the casting 43, and then the casting 43 is pressed by the first pressing clamp 27, and then the Y-shaped pressing block 32 is placed on the casting 43 and pressed by the second pressing clamp 34. After the fixing of the casting 43 is completed, the inspection tool 24 of the go / no-go gauge measuring tool is used to measure and record the casting 43, and quickly verify whether the size of the feature of the casting 43 relative to the reference is correct, and the operation is very convenient.

[0049] Finally, it should be noted that the above specific implementation methods are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to examples, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the spirit and scope of the technical solution of the present invention, which should be included in the scope of the claims of the present invention.

Claims

1. A method for controlling the size of a large complex thin-walled structure casting, characterized in that: The following steps are involved: Step S1. Setting the mold shrinkage rate, and designing an integrated investment casting mold according to the mold shrinkage rate; Step S2. Inject the wax material into the investment casting mold, hold the pressure for 50-80 seconds, and then open the mold to obtain a wax mold; Step S3. Connect the wax mold, the ingates and the runners together to obtain a wax tree; Step S4. Dipping the wax tree layer by layer with slurry, pouring sand and drying it to obtain a mold shell; Step S5. removing the wax from the mold shell to obtain a mold shell with a mold cavity; Step S6. Sintering the shell, then pouring the high-temperature metal into the shell, removing the shell after cooling, cutting the runner and gate, and obtaining the casting; Step S7. The casting is passed through a checking fixture to confirm the casting size, and the casting is obtained after it passes the inspection.

2. The method for controlling the size of a large complex thin-walled structure casting according to claim 1, characterized in that: In step S1, the investment casting mold comprises a lower mold (1) and an upper mold (2) arranged above the lower mold (1), the lower mold (1) comprises a lower mold plate (11), a side plate assembly is arranged on the outer periphery of the lower mold plate (11), the lower mold (1), the upper mold (2) and the side plate assembly are combined to form a mold cavity, a first movable block assembly is arranged on a side of the side plate assembly close to the cavity, a first groove and a second groove are arranged on the lower mold (1), a second movable block assembly is arranged in the first groove, and a third movable block assembly is arranged in the second groove.

3. The method for controlling the size of a large complex thin-walled structure casting according to claim 2, characterized in that: The side plate assembly comprises a first side plate (3) and a second side plate (4), wherein the first side plate (3) is arranged on the left and right sides of the lower mold (1), and the second side plate (4) is arranged on the upper and lower sides of the lower mold (1); the first movable block assembly comprises a first movable block (5), a second movable block (6) and a third movable block (7), wherein the first movable block (5) is arranged on both sides of the upper side of the lower mold (1), the second movable block (6) is arranged on the inner side of the first side plate (3), and the third movable block (7) is arranged on the inner side of the second side plate (4) located at the lower side.

4. The method for controlling the size of a large complex thin-walled structure casting according to claim 2, characterized in that: The second movable block assembly comprises a fourth movable block (8), a fifth movable block (9), a sixth movable block (10) and a seventh movable block (12); the fifth movable block (9) is arranged in the middle of the first groove; the sixth movable blocks (10) are arranged around the fifth movable block (9); the seventh movable block (12) is arranged in the gap between two adjacent sixth movable blocks (10); the fourth movable block (8) is arranged on the top of the third movable block assembly; the third movable block assembly comprises an eighth movable block (13), a ninth movable block (14), a tenth movable block (15) and an eleventh movable block (16); the eighth movable block (13) is arranged in the middle of the second groove; the ninth movable block (14) and the tenth movable block (15) are arranged in the second grooves on both sides of the eighth movable block (13) respectively; and the eleventh movable block (16) is arranged in the gap of the second groove between the ninth movable block (14) and the tenth movable block (15).

5. The method for controlling the size of a large complex thin-walled structure casting according to claim 1, characterized in that: In step S3, the wax tree comprises a side runner (17), a main runner (18) is arranged at the bottom of the side runner (17), the side runner (17) and the main runner (18) are connected, a pouring cup (19) is arranged in the middle of the bottom of the main runner (18), a plurality of inner gates (20) are arranged around the top of the side runner (17), and the other end of the inner gate (20) is connected to the wax mold (21).

6. The method for controlling the size of a large complex thin-walled structure casting according to claim 1, characterized in that: Step S4 is specifically as follows: S41. The wax material is immersed in the surface slurry, and the slurry is dried to obtain a wax material; S42. The wax material is immersed in the backing slurry, and the slurry is dried to obtain a wax material II; S43. Repeat step S2 seven times to obtain a mold shell.

7. The method for controlling the size of a large complex thin-walled structure casting according to claim 6, characterized in that: In step S41, the surface layer slurry includes silica sol and zircon powder, the weight ratio of the silica sol and the zircon powder is (2 - 2.5): (10-10.5), and the viscosity of the surface layer slurry is 35-45 S; in step S42, the back layer slurry includes silica sol and mullite powder, the mass ratio is 1: (1.4 -1.5), and the viscosity of the back layer slurry is 15-25S.

8. The method for controlling the size of a large complex thin-walled structure casting according to claim 1, characterized in that: In step S5, the temperature for removing the wax material is 170-180° C. and the pressure is 0.8-1 MPa; in step S6, the sintering temperature is 1100-1200° C. and the sintering time is 3-3.5 h.

9. The method for controlling the size of a large complex thin-walled structure casting according to claim 1, characterized in that: In step S7, the inspection tool comprises a base plate (22), a first baffle plate (23) is arranged on one side of the base plate (22), a inspection tool (24) is symmetrically arranged on one side of the first baffle plate (23), a handle (25) is symmetrically arranged on the other side of the first baffle plate (23), a support plate (26) is arranged on the other side of the base plate (22), a first pressing clamp (27) is arranged on the support plate (26), a first slide groove (39) is arranged on the base plate (22) between the first baffle plate (23) and the support plate (26), a first movable block (28) and a second movable block (29) are slidably arranged on the first slide groove (39), a spring (30) is arranged between the first movable block (28) and the second movable block (29), and the spring (30) is connected to the insert (39) in the middle 1), a Y-shaped pressure block (32) is arranged on the bottom plate (22), a support block (33) is arranged on a side of the bottom plate (22) close to the insert (31), a second pressure clamp (34) is arranged on the support block (32), the end of the second pressure clamp (34) away from the support block (33) is respectively connected to the insert (31) and the Y-shaped pressure block (32), a limit block (35) is arranged in the middle of the Y-shaped pressure block (32), second baffles (36) are arranged on the outer sides of the first movable block (28) and the second movable block (29), a positioning pin (37) is arranged on the second baffle (36), a second slide groove (40) is arranged on a side of the bottom plate (22) close to the support plate (26), and a setting screw (38) is slidably arranged on the first slide groove.

10. The method for controlling the size of a large complex thin-walled structure casting according to claim 9, characterized in that: Support pins (41) are arranged between the two ends of the Y-shaped portion of the Y-shaped pressing block (32) and the bottom plate (22), and a positioning piece (42) is arranged on a side surface of the first baffle plate (23) close to the Y-shaped pressing block (32).

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