A method for manufacturing a sand mold for a high-pressure cylinder of a steam turbine

Abstract

The application relates to a manufacturing method of a turbine high-pressure cylinder casting mold and a manufacturing method of a turbine high-pressure cylinder casting sand mold, and belongs to the technical field of high-pressure cylinder casting. The method comprises standard mold design, segmentation, design of locking parts and lifting parts, layer segmentation, plate blanking, blank production, blank processing, main body assembly, subsequent processing and detection. Through the method, an outer mold for forming an outer contour of a high-pressure cylinder and a plurality of core boxes (namely, an inner mold) for forming an inner contour of the high-pressure cylinder in the prior art are integrated into one standard mold entity, so that the required tooling and process steps for manufacturing the turbine high-pressure cylinder casting mold are less, the cost is lower, the operation during production is simpler, the precision of the produced standard mold entity is higher, the production difficulty is lower, the weight of the produced turbine high-pressure cylinder casting mold is lighter, and the size is more accurate.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of high-pressure cylinder casting, in particular to a manufacturing method of a mold for casting a high-pressure cylinder of a steam turbine, and to a manufacturing method of a sand mold for casting a high-pressure cylinder of a steam turbine. BACKGROUND

[0002] The basic size of a high-pressure cylinder of a steam turbine is in the range of 4-6m in length and 2-3m in diameter, and the wall thickness is mostly between 100-300mm. High-alloy heat-resistant steel material is generally used, and a sand mold is made using a high-pressure cylinder standard mold through casting process technology, and then a cast steel blank is poured in the sand mold. Then, it is cleaned, polished, heat treated, and numerically controlled processed.

[0003] In the prior art, the mold for casting a high-pressure cylinder of a medium or large steam turbine is mainly a wooden mold. The wooden mold has the advantages of low cost, mature technology, easy processing, light weight, high strength, environmental protection, and easy recycling. In order to ensure strength and facilitate processing or manual molding, the mold for casting a high-pressure cylinder is basically designed as a plurality of independent mold structures of an outer mold and a core box to make a sand mold, and the sand mold is assembled to form a casting cavity profile. Based on this, the current manufacturing process of the mold for casting a high-pressure cylinder requires a plurality of independent toolings to respectively produce different parts of the mold. This structure not only leads to large sand mold assembly workload and poor precision, but also has complex and tedious manufacturing process, high labor cost and high process cost. Moreover, the precision of the mold for casting a high-pressure cylinder of a medium or large steam turbine formed by assembling a plurality of independent parts is low. SUMMARY

[0004] The present application provides a manufacturing method of a mold for casting a high-pressure cylinder of a steam turbine, and a manufacturing method of a sand mold for casting a high-pressure cylinder of a steam turbine, for reducing the manufacturing cost of the mold for casting a high-pressure cylinder of a steam turbine and improving the manufacturing precision of the mold for casting a high-pressure cylinder of a steam turbine.

[0005] The present application is implemented by the following technical scheme: a manufacturing method of a mold for casting a high-pressure cylinder of a steam turbine, comprising:

[0006] Standard mold design: a standard mold model corresponding to the high-pressure cylinder of the steam turbine is designed by using three-dimensional software, and the standard mold model is decomposed into a main body model, an inner cavity movable block model, and an external movable block model by using three-dimensional software;

[0007] Segmentation: the height direction is from the median surface of the standard mold model to the direction away from the median surface, and the main body model is segmented into a first segment model, a second segment model, and a third segment model with a height less than 550mm in sequence along the height direction by using three-dimensional software;

[0008] Designing locking and lifting parts: design the first locking structure model and the second locking structure model in the three-dimensional software, the first locking structure model is used to lock the first segment model and the second segment model, and the second locking structure model is used to lock the second segment model and the third segment model, then design the lifting structure model and the demolding structure model, the lifting structure model is used to connect with the lifting equipment during lifting, and the demolding structure model is used to connect with the lifting equipment during demolding;

[0009] Layered segmentation: the first segment model, the second segment model and the third segment model are segmented into a plurality of layered plate models arranged in sequence along the height direction by using three-dimensional software, and a processing allowance is provided on the basis of the layered plate model to obtain a plurality of blanking plate models;

[0010] Plate blanking: a plurality of blanking plate entities are produced by a blanking machine according to the blanking plate model, and internal cavity movable block entities, external movable block entities, first locking structure entities, second locking structure entities, lifting structure entities and demolding structure entities are produced by machining according to the designed internal cavity movable block model, external movable block model, first locking structure model, second locking structure model, lifting structure model and demolding structure model;

[0011] Production of blanks: a plurality of blanking plate entities are stacked and glued to form a first segment blank corresponding to the first segment model, a second segment blank corresponding to the second segment model, and a third segment blank corresponding to the third segment model;

[0012] Blank processing: the first segment blank, the second segment blank and the third segment blank are processed by a three-axis woodworking CNC machine to obtain a first segment entity, a second segment entity and a third segment entity, and then the internal cavity movable block entity and the external movable block entity are processed by the three-axis woodworking CNC machine;

[0013] Main assembly: the second segment entity is stacked on the first segment entity, then the first segment entity and the second segment entity are locked by the first locking structure entity, then the third segment entity is stacked on the second segment entity, and then the second segment entity and the third segment entity are locked by the second locking structure entity to obtain a main body entity, and the lifting structure entity is installed on the third segment entity to obtain a main body standard entity;

[0014] Subsequent processing and detection: first, the main body standard entity, the internal cavity movable block entity and the external movable block entity are surface treated, then the internal cavity movable block entity and the external movable block entity are installed on the main body standard entity to obtain a standard mold entity, then the standard mold entity is surface treated, and then three-dimensional detection is performed by using a three-dimensional detection instrument to judge the dimensional accuracy of the standard mold entity.

[0015] Further, in order to better realize the present application, in the standard mold design step:

[0016] The ratio of the standard mold number model to the high-pressure cylinder of the steam turbine is 1:1.

[0017] Further, in order to better realize the present application, the standard mold number model has a flange, and the specific segmentation mode of the segmentation step is:

[0018] A first segmentation surface is arranged at a position greater than or equal to one-half of the height of the flange, and a second segmentation surface is arranged at a position d above the first segmentation surface, wherein d≤550mm;

[0019] The part between the middle surface and the first segmentation surface constitutes a first segment number model, the part between the first segmentation surface and the second segmentation surface constitutes a second segment number model, and the part above the second segmentation surface constitutes a third segment number model.

[0020] Further, in order to better realize the present application, in the step of designing the locking member and the lifting member:

[0021] The first locking structure number model is designed to include a stud and a locking nut, a steel plate is arranged at one end of the stud, the stud is screwed with the locking nut after penetrating the second segment number model and the first segment number model in sequence, and the first segment number model and the second segment number model are clamped by the locking nut and the steel plate;

[0022] The second locking structure number model is designed to include a main profiled steel belt and a secondary profiled steel belt, the main profiled steel belt is fixed to the third segment number model and the second segment number model by wooden screws, and the main profiled steel belt is fixed to the steel plate on the stud and tightly binds the second segment number model and the third segment number model from the outside, and the secondary profiled steel belt is also fixed to the third segment number model and the second segment number model by wooden screws to tighten the second segment number model and the third segment number model;

[0023] The lifting structure number model is designed to include an end plate, a pressing plate, and a lifting rod with a lifting hole, the end plate is fixed at the bottom end of the lifting rod, the lifting rod penetrates the third segment number model from bottom to top and the lifting hole extends above the third segment number model, and then the pressing plate is fixed at the middle of the lifting rod and below the lifting hole, the pressing plate and the end plate clamp the third segment number model, the main profiled steel belt is fixed with the pressing plate, and the secondary profiled steel belt includes a connecting steel belt, which corresponds to the inside and outside of the main profiled steel belt, and the connecting steel belt is fixed with the end plate;

[0024] The demolding structure number model is designed to include a U-shaped rod and a connecting nut fixed at the opening of the U-shaped rod, when demolding is needed, the connecting nut is screwed with the stud and the locking nut is located between the connecting nut and the steel plate.

[0025] Further, in order to better realize the present application, in the step of segmenting by layers:

[0026] The first section of the numerical model is divided into a plurality of 25mm-thick layered board numerical models according to a horizontal equal-height layering method, the second section of the numerical model is also divided into a plurality of 25mm-thick layered board numerical models according to the horizontal equal-height layering method, and the third section of the numerical model is also divided into a plurality of 25mm-thick layered board numerical models according to the horizontal equal-height layering method.

[0027] The machining allowance for the blanking of the layered board numerical model is 15-20mm, and the generated blanking board numerical model has a frame structure.

[0028] Further, in the blanking step of the present application, the following is performed:

[0029] Before blanking, the blanking board numerical model is divided into a plurality of single board numerical models connected end to end by using three-dimensional software, and the blanking process specifically comprises the following steps: 1220 25mm standard boards are processed into single board entities corresponding to the single board numerical models;

[0030] The blanking board entity is obtained by connecting a plurality of single board entities end to end to form a frame-shaped blanking board entity, and a joint is formed between the single board entities.

[0031] Further, in the blanking step of the present application, the following is performed:

[0032] The joints of the blanking board entities stacked in the upper and lower layers are staggered.

[0033] Further, in the blanking step of the present application, the following is performed:

[0034] When the first section of the blank is processed into the first section entity, the outer contour of the first section entity is first processed by using a three-axis woodworking numerical control machine tool, and then the first section blank is flipped by 180° to process the inner contour of the first section entity, and the coordinate reference of the inner contour and the outer contour is coincident;

[0035] When the second section of the blank is processed into the second section entity, the outer contour of the second section entity is first processed by using a three-axis woodworking numerical control machine tool, and then the second section blank is flipped by 180° to process the inner contour of the second section entity, and the coordinate reference of the inner contour and the outer contour is coincident;

[0036] When the third section of the blank is processed into the third section entity, the outer contour of the third section entity is first processed by using a three-axis woodworking numerical control machine tool, and then the third section blank is flipped by 180° to process the inner contour of the third section entity, and the coordinate reference of the inner contour and the outer contour is coincident.

[0037] Further, in the blanking step of the present application, the following is performed:

[0038] The specific way of assembling the second section entity on the first section entity is as follows: firstly, the second section entity is stacked on the first section entity, then the size is checked, and the size is adjusted until the size is completely correct, then the second section entity is hoisted away after marking, the latex is brushed on the joint surface of the first section entity, then the second section entity is hoisted to the joint surface of the first section entity, the second section entity is bonded to the first section entity by using the latex, and then the first locking structure entity is used to lock the second section entity and the first section entity.

[0039] The specific way of assembling the third section entity on the second section entity is as follows: firstly, the third section entity is stacked on the second section entity, then the size is checked, and the size is adjusted until the size is completely correct, then the third section entity is hoisted away after marking, the latex is brushed on the joint surface of the second section entity, then the third section entity is hoisted to the joint surface of the second section entity, the third section entity is bonded to the second section entity by using the latex, and then the second locking structure entity is used to lock the third section entity and the second section entity.

[0040] Further, in order to better realize the present application, in the subsequent processing and detection steps:

[0041] The surface treatment of the main standard entity, the inner cavity movable block entity and the external movable block entity is as follows: firstly, a layer of putty is scraped on the outer surface of the main standard entity, the inner cavity movable block entity and the external movable block entity, and then the surface is polished.

[0042] Compared with the prior art, the present application has the following beneficial effects:

[0043] The manufacturing method of the mold for casting the high-pressure cylinder of the steam turbine and the manufacturing method of the sand mold for casting the high-pressure cylinder of the steam turbine provided by the present application integrate the outer mold for forming the outer contour of the high-pressure cylinder and the plurality of core boxes (i.e., the inner mold) for forming the inner contour of the high-pressure cylinder into one standard mold entity, so that the required tooling and process steps are less, the cost is lower, the operation during production is more convenient, the precision of the produced standard mold entity is higher, the large-size mold for casting the high-pressure cylinder of the steam turbine can be processed into three sections by using a three-axis woodworking numerical control machine tool, the three sections are assembled into a complete standard mold entity after processing, the production difficulty and cost are significantly reduced, the produced standard mold entity does not need a steel framework for support, the weight of the produced standard mold entity is lighter, the standard mold entity is convenient to carry and store, and the size is more accurate. BRIEF DESCRIPTION OF DRAWINGS

[0044] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description only constitute some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained from these drawings without creative labor.

[0045] Figure 1 is a flow chart of the manufacturing method of the mold for casting the high-pressure cylinder of the steam turbine provided by the embodiments of the present application;

[0046] Figure 2 is a structural schematic diagram of the standard mold number model designed in the embodiments of the present application;

[0047] Figure 3 is a structural schematic diagram of the standard mold number model shown in Figure 2 after being disassembled and activated;

[0048] Figure 4 is a structural schematic diagram of the segmented and divided main body number model in the embodiments of the present application (without the locking through holes and the conformal grooves);

[0049] Figure 5 is a top view structural schematic diagram of the segmented and divided main body number model in the embodiments of the present application;

[0050] Figure 6 is a bottom view structural schematic diagram of the segmented and divided main body number model in the embodiments of the present application;

[0051] Figure 7 is an assembly structural schematic diagram of the first segment number model and the second segment number model in the embodiments of the present application;

[0052] Figure 8 is an installation structural schematic diagram of the first locking structure number model, the second locking structure number model and the hoisting structure number model on the main body number model in the embodiments of the present application;

[0053] Figure 9 is a structural schematic diagram of the first locking structure number model in the embodiments of the present application;

[0054] Figure 10 is a structural schematic diagram of the second locking structure number model in the embodiments of the present application;

[0055] Figure 11 is a structural schematic diagram of the hoisting structure number model in the embodiments of the present application;

[0056] Figure 12 is a structural schematic diagram of the demolding structure number model in the embodiments of the present application;

[0057] Figure 13is a structure schematic diagram of a layered board numerical model in the embodiment of the present application;

[0058] Figure 14 is a structure schematic diagram of a first section numerical model after layered segmentation in the embodiment of the present application;

[0059] Figure 15 is a structure schematic diagram when a single board numerical model is spliced in the embodiment of the present application;

[0060] Figure 16 is a structure schematic diagram when a three-axis woodworking numerical control machine tool processes the outer contour of a second section blank in the embodiment of the present application;

[0061] Figure 17 is a structure schematic diagram when a three-axis woodworking numerical control machine tool processes the inner contour of a second section blank in the embodiment of the present application.

[0062] In the figure:

[0063] 1-standard numerical model, 2-main numerical model, 3-inner cavity movable block numerical model, 4-external movable block numerical model, 5-first section numerical model, 6-second section numerical model, 7-third section numerical model, 8-female pin numerical model, 9-male pin numerical model, 10-locking through hole, 101-upper counterbore, 102-lower counterbore, 11-first locking structure numerical model, 111-stud, 112-locking nut, 113-steel plate, 12-second locking structure numerical model, 121-main profiled steel belt, 122-vice profiled steel belt, 13-profiled groove, 14-hoisting structure numerical model, 141-hoisting rod, 142-end plate, 143-pressing plate, 15-demolding structure numerical model, 151-U-shaped rod, 152-connecting nut, 16-layered board numerical model, 17-blank board numerical model, 18-single board numerical model, 19-middle split surface, 20-three-axis woodworking numerical control machine tool. DETAILED DESCRIPTION

[0064] To make the objectives, technical solutions, and advantages of the present application clearer, the technical solutions of the present application will be described in detail below. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of the present application.

[0065] Embodiment 1

[0066] The embodiment provides a manufacturing method of a turbine high-pressure cylinder casting mold, which is used for producing a standard mold (which can also be understood as a standard model) corresponding to a turbine high-pressure cylinder accurately, and by means of the standard mold, an accurate sand mold for casting the turbine high-pressure cylinder can be obtained, and a turbine high-pressure cylinder with accurate size can be obtained by casting in the sand mold. Figures 1 to 17As shown, the method for manufacturing the mold for casting the high-pressure cylinder of the steam turbine comprises the following steps:

[0067] Step 1: standard mold design. Specifically, a standard mold model 1 corresponding to the high-pressure cylinder of the steam turbine is designed by using three-dimensional software in a 1:1 ratio, as shown in Figure 2 As shown, it should be noted that the standard mold model 1 does not include a lifting unit. Then, the standard mold model 1 is decomposed into a main body model 2, an inner cavity movable block model 3, and an external movable block model 4 by using three-dimensional software, as shown in Figure 3 As shown, it should be noted that the decomposition process is actually to facilitate demolding and machining by the three-axis woodworking CNC machine 20, that is, the parts on the standard mold model 1 that hinder demolding and machining by the three-axis woodworking CNC machine 20 are decomposed and taken out to obtain the inner cavity movable block model 3 and the external movable block model 4. It is worth noting that decomposition and taking out are common means in mold design, so they will not be described in detail here.

[0068] Step 2: segmentation. Specifically, as shown in Figure 4 As shown, the height direction is defined as the direction away from the median surface 19 of the standard mold model 1, and the main body model 2 is segmented into a first segment model 5, a second segment model 6, and a third segment model 7 each having a height less than 550 mm along the height direction by using three-dimensional software. It is worth noting that the maximum safe machining height of the existing three-axis woodworking CNC machine 20 in the vertical direction is 550 mm, while the size of the steam turbine high-pressure cylinder in the height direction is greater than 550 mm. Therefore, the three-axis woodworking CNC machine 20 cannot be used to realize full CNC machining and forming of the inner and outer contours of the standard mold at one time. Therefore, the method provided in this embodiment ingeniously segments the standard mold model 1 into three segments (i.e., the first segment model 5, the second segment model 6, and the third segment model 7) along the height direction, and the height of each segment is less than 550 mm. In this way, the outer contour or the inner contour of each segment can be machined by the three-axis woodworking CNC machine 20 at one time.

[0069] In this step, the specific segmentation method is as follows: a first segmentation surface is set at a position greater than or equal to one-half of the flange height from the median surface 19, and a second segmentation surface is set at a position d away from the first segmentation surface, where d≤550 mm. The part between the median surface 19 and the first segmentation surface constitutes the first segment model 5, the part between the first segmentation surface and the second segmentation surface constitutes the second segment model 6, and the part above the second segmentation surface constitutes the third segment model 7. It is worth noting that the standard mold model 1 and the steam turbine high-pressure cylinder are designed in a 1:1 ratio, and the steam turbine high-pressure cylinder has a flange. Therefore, the standard mold model 1 also has a flange.

[0070] The height of the first segment digital model 5, the second segment digital model 6 and the third segment digital model 7 obtained after decomposition is less than or equal to 550 mm, therefore, the first segment entity, the second segment entity and the third segment entity produced based on the first segment digital model 5, the second segment digital model 6 and the third segment digital model 7 can be machined for the outer contour and the inner contour by the three-axis woodworking numerical control machine tool 20.

[0071] In order to ensure accurate assembly and convenient operation in the later stage, as shown in Figure 7 , positioning references are designed between the first segment digital model 5 and the second segment digital model 6 and between the second segment digital model 6 and the third segment digital model 7. Specifically, the positioning references include male pin digital models 9 and female pin digital models 8 which cooperate with each other, wherein the female pin digital models 8 are designed on the first segment digital model 5 and the second segment digital model 6, and the male pin digital models 9 are designed on the second segment digital model 6 and the third segment digital model 7. When the first segment digital model 5 and the second segment digital model 6 are assembled, the male pin digital model 9 on the second segment digital model 6 is inserted into the female pin digital model 8 on the first segment digital model 5, so as to realize the positioning of the second segment digital model 6 on the first segment digital model 5; when the second segment digital model 6 and the third segment digital model 7 are assembled, the male pin digital model 9 on the third segment digital model 7 is inserted into the female pin digital model 8 on the second segment, so as to realize the positioning of the third segment digital model 7 on the second segment digital model 6. In addition, three sets of male pin digital models 9 and female pin digital models 8 which cooperate with each other are designed between the first segment digital model 5 and the second segment digital model 6, and three sets of male pin digital models 9 and female pin digital models 8 which cooperate with each other are also designed between the second segment digital model 6 and the third segment digital model 7, and the three sets of male pin digital models 9 and female pin digital models 8 of each layer are distributed on the three vertices of the same triangle. The above description is that the male pin is on the top and the female pin is on the bottom, of course, the female pin can be arranged on the top and the male pin can be arranged on the bottom, in this case, the male pin digital models 9 are arranged on the first segment digital model 5 and the second segment digital model 6, and the female pin digital models 8 are arranged on the second segment digital model 6 and the third segment digital model 7, when assembled, the second segment digital model 6 is stacked on the first segment digital model 5, the female pin digital model 8 on the second segment digital model 6 is sleeved on the male pin digital model 9 of the first segment digital model 5, the third segment digital model 7 is stacked on the second segment digital model 6, and the female pin digital model 8 on the third segment digital model 7 is sleeved on the male pin digital model 9 of the second segment digital model 6.

[0072] Step 3: design locking members and lifting members. Specifically, as shown in Figure 5 , Figure 6 , Figure 8 , the first locking structure digital model 11 and the second locking structure digital model 12 are designed in the three-dimensional software, the first locking structure digital model 11 is used to lock the first segment digital model 5 and the second segment digital model 6, and the second locking structure digital model 12 is used to lock the second segment digital model 6 and the third segment digital model 7, then the lifting structure digital model 14 and the demolding structure digital model 15 are designed, the lifting structure digital model 14 is used to connect with the lifting equipment during lifting, and the demolding structure digital model 15 is used to connect with the lifting equipment during demolding.

[0073] AsFigure 9 As shown, the first locking structure number module 11 is designed to include a stud 111 and a locking nut 112, and a steel plate 113 is arranged at one end of the stud 111, and the outer diameter of the steel plate 113 is greater than the diameter of the stud 111. The stud 111 is sequentially threaded through the second section number module 6 and the first section number module 5 and then screwed with the locking nut 112. In fact, the first section number module 5 and the second section number module 6 are both designed with locking through holes 10, and the first section number module 5 and the second section number module 6 are positioned by the positioning datum therebetween, and then the locking through hole 10 on the first section number module 5 coincides with the locking through hole 10 on the second section number module 6, and a sunken hole 102 is arranged on the bottom surface of the first section number module 5 (i.e. the aforementioned middle surface 19) and located at the bottom end of the locking through hole 10 thereof, and a sunken hole 101 is arranged on the top surface of the second section number module 6 and located at the top end of the locking through hole 10 thereof, and when the first locking structure number module 11 is assembled, the stud 111 is sequentially threaded through the locking through hole 10 on the second section number module 6 and the locking through hole 10 on the first section number module 5 from top to bottom, and the bottom end of the stud 111 is arranged in the sunken hole 102, and then the locking nut 112 is screwed at the bottom of the stud 111 and arranged in the sunken hole 102, and the steel plate 113 on the stud 111 is arranged in the sunken hole 101, and finally the first section number module 5 and the second section number module 6 are clamped by the locking nut 112 and the steel plate 113.

[0074] It is worth noting that the stud 111, the steel plate 113 and the locking nut 112 are all number modules. The number of the first locking structure number module 11 designed between the first section number module 5 and the second section number module 6 is four groups, and the four groups of first locking structure number modules 11 are respectively distributed at the four corners of the main body number module 2, that is, the four first locking structure number modules 11 are respectively distributed at the four vertices of the same rectangle. The thickness of the steel plate 113 is 20 mm, the depth of the sunken hole 101 is 30 mm, the steel plate 113 is completely immersed in the sunken hole 101, the depth of the sunken hole 102 is 130 mm, and the locking nut 112 is also provided with a gasket, and the gasket, the locking nut 112 and the bottom end of the stud 111 are all completely arranged in the sunken hole 102. In fact, the steel plate 113 and the stud 111 are fixed by welding.

[0075] As shown in the drawings, Figure 10 As shown, the second locking structure number module 12 is designed to include a main profiled steel belt 121 and a secondary profiled steel belt 122. It should be noted that since the outer contour and the inner contour of the second section number module 6 and the third section number module 7 are both with curvature, therefore, the main profiled steel belt 121 and the secondary profiled steel belt 122 are both designed with profiled design in order to completely fit the outer contour and the inner contour of the second section number module 6 and the third section number module 7.

[0076] The main conformal steel belt 121 is fixed with the third section number module 7 and the second section number module 6 by wooden screws, and the main conformal steel belt 121 is welded with the steel plate 113 on the stud 111 and is fixed from the outside to tighten the second section number module 6 and the third section number module 7. It is worth noting that the number of the main conformal steel belt 121 is two, and the number of the above-mentioned first locking structure number module 11 is four. The main conformal steel belt 121 is fixed with the steel plate 113 on the stud 111, so as to better tighten the third section number module 7 to the second section number module 6. In fact, the main conformal steel belt 121 is welded with the steel plate 113 on the stud 111.

[0077] The auxiliary conformal steel belt 122 is also fixed with the third section number module 7 and the second section number module 6 by wooden screws, so as to tighten the second section number module 6 and the third section number module 7. The number of the auxiliary conformal steel belt 122 is multiple, which is distributed at different positions between the second section number module 6 and the third section number module 7. Part of the auxiliary conformal steel belt 122 is a connecting steel belt, which corresponds to the inside and outside of the main conformal steel belt 121. Specifically, the main conformal steel belt 121 is located outside the contour of the main body number module 2, while the connecting steel belt is located inside the contour of the main body number module 2 and corresponds to the inside and outside of the main conformal steel belt 121. The rest of the auxiliary conformal steel belt 122 is also in pairs, and the two auxiliary conformal steel belts 122 in each pair correspond to the inside and outside.

[0078] It is worth noting that the above-mentioned main conformal steel belt 121, auxiliary conformal steel belt 122 and wooden screw are also number modules. Moreover, part of the auxiliary conformal steel belt 122 is also fixed with the first section number module 5 by wooden screws, that is, the auxiliary conformal steel belt 122 not only connects the second section number module 6 and the third section number module 7, but also connects the first section number module 5. In addition, in order to avoid the main conformal steel belt 121 and the auxiliary conformal steel belt 122 protruding from the outer contour and the inner contour of the main body number module 2, in this embodiment, the conformal grooves 13 are arranged at the outer contour and the inner contour of the second section number module 6, the third section number module 7 and part of the first section number module 5, and the main conformal steel belt 121 and the auxiliary conformal steel belt 122 are respectively embedded in different conformal grooves 13, so that the main conformal steel belt 121 and the auxiliary conformal steel belt 122 will not protrude from the outer contour and the inner contour of the main body number module 2.

[0079] As Figure 11As shown, the hoisting structure number module 14 is designed to include an end plate 142, a pressing plate 143, and a hoisting rod 141 with a hoisting hole. The end plate 142 is fixed at the bottom end of the hoisting rod 141, the hoisting rod 141 penetrates the third section number module 7 from bottom to top and the hoisting hole extends above the third section number module 7 (specifically, the top of the third section number module 7 is provided with a through hole matched with the hoisting rod 141, and the hoisting rod 141 is connected in the through hole), and then the pressing plate 143 is fixed at the middle of the hoisting rod 141 and below the hoisting hole. The pressing plate 143 and the end plate 142 clamp the third section number module 7, so as to fix the hoisting structure number module 14 on the main body number module 2. The main profiled steel belt 121 is fixed with the pressing plate 143, and the connecting steel belt is fixed with the end plate 142. The number of the main profiled steel belt 121 is two, and the number of the hoisting structure number module 14 is also two. The two hoisting structure number modules 14 are evenly distributed on the top of the main body number module 2. When hoisting, the hook or steel wire rope of the hoisting equipment is connected to the hoisting hole for hoisting.

[0080] It should be noted that the end plate 142, the pressing plate 143, and the hoisting rod 141 are all number modules. By the above arrangement, the first locking structure number module 11, the second locking structure number module 12, and the hoisting structure number module 14 in the embodiment are fixedly integrated on the main body number module 2. In fact, the end plate 142 is welded and fixed at the bottom end of the hoisting rod 141, the pressing plate 143 is provided with a through hole, and after the hoisting rod 141 penetrates the third section number module 7, the pressing plate 143 is sleeved on the hoisting rod 141 and welded and fixed; the main profiled steel belt 121 is fixed with the pressing plate 143 by welding, and the connecting steel belt is fixed with the end plate 142 by welding.

[0081] As shown in the figure, Figure 12 The demolding structure number module 15 is designed to include a U-shaped rod 151 and a connecting nut 152 fixed at the opening of the U-shaped rod 151. When demolding is needed, the connecting nut 152 is screwed with the stud 111 and the locking nut 112 is located between the connecting nut 152 and the steel plate 113. Since the number of the stud 111 is four, the number of the demolding structure number module 15 in the embodiment is also four, and the four demolding structure number modules 15 are screwed on the four studs 111 respectively. Of course, when demolding is not needed, the demolding structure number module is not needed, and only when demolding is needed, the demolding structure number module 15 is connected. After the demolding structure number module 15 is connected, the connecting nut 152 is embedded in the sinking hole 102, and part of the U-shaped rod 151 is placed outside the sinking hole 102, so as to connect the hook or steel wire rope of the hoisting equipment when demolding.

[0082] It is worth noting that the U-shaped rod 151 and the connecting nut 152 are all number modules.

[0083] Step 4: Layered cutting. Specifically, the first section numerical model 5, the second section numerical model 6 and the third section numerical model 7 are all divided into a plurality of layered plate numerical models 16 arranged in sequence along the height direction by using three-dimensional software, and a machining allowance is provided on the basis of the layered plate numerical model 16 to obtain a plurality of blanking plate numerical models 17.

[0084] In this step, the first section numerical model 5 is divided into a plurality of layered plate numerical models 16 with a thickness of 25 mm according to the horizontal equal-height layering method, the second section numerical model 6 is also divided into a plurality of layered plate numerical models 16 with a thickness of 25 mm according to the horizontal equal-height layering method, and the third section numerical model 7 is also divided into a plurality of layered plate numerical models 16 with a thickness of 25 mm according to the horizontal equal-height layering method. It is worth noting that the layered plate numerical model 16 is actually formed by extracting the maximum contour line of each layer of plate by three-dimensional software and then stretching the function. Moreover, in this step, the machining allowance provided when obtaining the blanking plate numerical model 17 from the layered plate numerical model 16 is 15-20 mm, and the generated blanking plate numerical model 17 has a frame structure.

[0085] Step 5: Plate blanking. Specifically, a plurality of blanking plate entities are produced by a blanking machine according to the blanking plate numerical model 17, so that the size of the blanking plate entity obtained in this way is accurate.

[0086] Moreover, the inner cavity movable block entity, the outer movable block entity, the first locking structure entity (i.e., the stud 111, the steel plate 113 and the locking nut 112), the second locking structure entity (i.e., the main profiled steel belt 121 and the auxiliary profiled steel belt 122), the hoisting structure entity (i.e., the end plate 142, the hoisting rod 141 and the pressing plate 143) and the demolding structure entity (i.e., the U-shaped rod 151 and the connecting nut 152) are produced by machining according to the designed inner cavity movable block numerical model 3, the outer movable block numerical model 4, the first locking structure numerical model 11, the second locking structure numerical model 12, the hoisting structure numerical model 14 and the demolding structure numerical model 15. In addition, the male pin entity corresponding to the male pin numerical model 9 and the female pin entity corresponding to the female pin numerical model 8 are obtained by purchase.

[0087] In this step, before blanking, the blanking plate numerical model 17 also needs to be divided into a plurality of single plate numerical models 18 connected end to end by using three-dimensional software. The blanking process specifically comprises using a blanking machine to process a plurality of standard plates with a size of 2440 1220 25 mm into single plate entities corresponding to the single plate numerical model 18. The way to obtain the blanking plate entity is to splice a plurality of single plate entities end to end into a frame-shaped blanking plate entity, and a joint is formed between the single plate entities. In this way, the utilization rate of the plate can be improved, and the cost can be further reduced.

[0088] Step 6: production of blanks. Specifically, a plurality of blank plate entities are stacked on top of each other and glued to form a first section blank corresponding to the first section numerical model 5, a second section blank corresponding to the second section numerical model 6, and a third section blank corresponding to the third section numerical model 7. In this step, when stacking the blank plate entities, the seams of the upper and lower layers of blank plate entities need to be staggered, which can reduce the probability of breakage of the first section blank, the second section blank, and the third section blank during production.

[0089] Step 7: blank processing. Specifically, the first section blank, the second section blank, and the third section blank are processed using the three-axis woodworking CNC machine 20 to obtain the first section entity, the second section entity, and the third section entity. The specific implementation of this step is as follows:

[0090] When the first section blank is processed into the first section entity, the outer contour of the first section entity is first processed using the three-axis woodworking CNC machine 20, and then the first section blank is flipped 180° and the inner contour of the first section entity is processed. The coordinate reference of the inner contour and the outer contour is coincident during processing. In this way, the precision consistency of the outer contour and the inner contour of the final first section entity can be ensured.

[0091] When the second section blank is processed into the second section entity, the outer contour of the second section entity is first processed using the three-axis woodworking CNC machine 20, and then the second section blank is flipped 180° and the inner contour of the second section entity is processed. The coordinate reference of the inner contour and the outer contour is coincident during processing. In this way, the precision consistency of the outer contour and the inner contour of the final second section entity can be ensured.

[0092] When the third section blank is processed into the third section entity, the outer contour of the third section entity is first processed using the three-axis woodworking CNC machine 20, and then the third section blank is flipped 180° and the inner contour of the third section entity is processed. The coordinate reference of the inner contour and the outer contour is coincident during processing. In this way, the precision consistency of the outer contour and the inner contour of the final third section entity can be ensured.

[0093] Then the inner cavity movable block entity and the outer movable block entity are processed using the three-axis woodworking CNC machine 20, so that the precision of the inner cavity movable block entity and the outer movable block entity is also guaranteed.

[0094] In this step, after the first section entity, the second section entity, and the third section entity are processed, the female pin entity is assembled on the first section entity, the female pin entity and the male pin entity are assembled on the second section entity, and the male pin entity is assembled on the third section entity.

[0095] Step 8: Assembling the main body. Specifically, the second section is stacked on the first section, and then the first section and the second section are locked by the first locking structure, and then the third section is stacked on the second section, and then the second section and the third section are locked by the second locking structure, to obtain the main body, and then the lifting structure is installed on the third section to obtain the main body standard.

[0096] In this step, the second section is assembled on the first section in the following way: first, the second section is stacked on the first section, and when stacking, the male pin on the second section is inserted into the female pin on the first section, and then the size is checked, and if the size is not correct, it is adjusted until the size is completely correct, and then a mark is made, the second section is lifted, and then the first section is coated with glue, and then the second section is lifted to the joint surface of the first section, and then the second section is bonded to the first section by glue, and then the first section and the second section are locked by the first locking structure. The specific operation of locking the first section and the second section by the first locking structure is as follows: the stud 111 is passed through the second section and the first section from top to bottom, so that the steel plate 113 on the stud 111 sinks into the upper sink hole 101 on the top surface of the second section, and then a gasket is sleeved on the lower part of the stud 111, and then the locking nut 112 is screwed, and the gasket and the locking nut 112 are located in the lower sink hole 102 on the middle surface 19 of the first section, and the bottom end of the stud 111 is also located in the lower sink hole 102.

[0097] The specific way of assembling the third section on the second section is as follows: first, the third section is stacked on the second section, and when stacking, the male pin on the third section is inserted into the female pin on the second section, and then the size is checked, and if the size is not correct, it is adjusted until the size is completely correct, and then a mark is made, the third section is lifted, and then the second section is coated with glue, and then the third section is lifted to the joint surface of the second section, and then the third section is bonded to the second section by glue, and then the second section and the third section are locked by the second locking structure. The specific operation of locking the second section and the third section by the second locking structure is as follows: the main profiled steel belt 121 and the auxiliary profiled steel belt 122 are fixed in the corresponding profiled groove 13 by wood screws, and the main profiled steel belt 121 is welded and fixed with the steel plate 113 on the stud 111. In addition, the lifting structure needs to be pre-installed on the third section of the main body, and the connecting steel belt in the main profiled steel belt 121 and the auxiliary profiled steel belt 122 is pre-welded and fixed with the pressing plate 143 and the end plate 142 of the lifting structure, respectively.

[0098] Step 9: Post-processing and detection. Specifically, surface treatment is first performed on the main standard entity, the inner cavity block entity and the outer block entity, and then the inner cavity block entity and the outer block entity are both installed on the main standard entity to obtain a standard mold entity, and then surface treatment is performed on the standard mold entity, and then three-dimensional detection is performed using a three-dimensional detection instrument to obtain a detection report to determine the dimensional accuracy of the standard mold entity. It should be noted that the three-dimensional detection instrument described above is a prior art, and therefore will not be described in detail here.

[0099] In this step, the surface treatment of the main standard entity, the inner cavity block entity and the outer block entity is performed by first applying a layer of putty on the outer surface of the main standard entity, the inner cavity block entity and the outer block entity, and then polishing the surface. By applying a layer of putty on the surface of the main standard entity, the upper sink hole 101, the profiled groove 13, the profiled steel belt and the surface processing defects can be completely covered and repaired, while the surface strength is increased. By polishing the surface, the surface of the main standard entity can be made smoother and more even.

[0100] At this point, a standard mold entity with the shape and size of the steam turbine high-pressure cylinder 1:1 is produced. The manufacturing method of the steam turbine high-pressure cylinder casting mold provided in this embodiment integrates the outer mold for forming the outer contour of the high-pressure cylinder and the plurality of core boxes (i.e., the inner mold) for forming the inner contour of the high-pressure cylinder into one standard mold entity, which requires fewer tooling and process steps during production, is lower in cost, and is easier to operate during production. The standard mold entity produced has higher precision. Moreover, by designing the standard mold entity in segments and manufacturing and assembling it in layers, a large-size steam turbine high-pressure cylinder casting mold can be machined into three segments using a three-axis woodworking CNC machine tool 20, and after machining, the three segments are assembled into a complete standard mold entity, significantly reducing the production difficulty and cost. Furthermore, the standard mold entity produced does not require a steel framework for support, so the standard mold entity produced is lighter in weight, making it easier to handle and store.

[0101] Example 2:

[0102] This embodiment is a specific use method of the standard mold entity obtained in Example 1, which uses the above-mentioned standard mold entity to obtain a sand mold for casting a steam turbine high-pressure cylinder. Specifically:

[0103] First, the main standard entity and the outer block entity are hung on the sand box bottom plate, and the sand box is placed around them, and the main standard entity and the outer block entity are completely covered with resin sand, and after the sand mold is completely solidified, the lower box sand mold is formed, obtaining the lower box sand mold.

[0104] Then the lower box sand mold and the main body standard entity and the external loose block entity are turned over 180°, the middle split surface 19 and the inner cavity profile of the main body standard entity are completely upward, all the inner cavity loose block entity and the riser mold are assembled to the main body standard entity, the split surface is sleeved with the special sand box, and then the resin sand is filled to completely cover all the main body standard entity, the inner cavity loose block entity, the external loose block entity and the riser mold, and after the sand mold is solidified, the upper box sand mold is formed, and the upper box sand mold is obtained.

[0105] According to the prior art of the sand mold design, the closing positioning reference is arranged between the upper box sand mold and the lower box sand mold. When the upper box sand mold and the lower box sand mold are closed together, the mold cavity consistent with the profile of the steam turbine high-pressure cylinder is formed between the upper box sand mold and the lower box sand mold, and the qualified steam turbine high-pressure cylinder can be obtained after casting in the mold cavity. When the upper box sand mold is solidified, the demolding can be performed. The demolding sequence is that the upper box sand mold is hoisted upward by the crane to a certain safety height above the split surface of the upper and lower sand boxes, and then is hoisted to the special placing site to be placed flat, then the demolding structure entity is mounted on the threaded column 111, the hook or steel wire of the hoisting equipment is hung on the U-shaped rod 151 of the demolding structure entity, and the steam turbine high-pressure cylinder main mold is taken out from the lower box sand mold by using the hoisting equipment. It is easy to understand that the standard mold entity in the embodiment is actually the mold for casting the steam turbine high-pressure cylinder.

[0106] The above is only a specific embodiment of the present application, but the protection scope of the present application is not limited to this. Any person skilled in the art can easily think of changes or replacements within the technical range disclosed in the present application, which should be covered in the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A method of manufacturing a sand mold for casting a high-pressure cylinder of a steam turbine, characterized by, The utility model relates to a kind of standard mold design, including: standard mold design: utilize three-dimensional software design to obtain the standard mold number model (1) corresponding with steam turbine high-pressure cylinder, and utilize three-dimensional software to obtain main body number model (2), internal cavity movable block number model (3) and external movable block number model (4) by the standard mold number model (1) decomposition; Segmentation: from the middle surface (19) of standard mold number model (1) to the direction of away from middle surface (19) as height direction, utilize three-dimensional software to sequentially segment main body number model (2) into first segment number model (5), second segment number model (6) and third segment number model (7) with height less than 550mm along height direction; Design locking piece and lifting piece: design first locking structure number model (11) and second locking structure number model (12) in three-dimensional software, first locking structure number model (11) is used to lock first segment number model (5) and second segment number model (6), second locking structure number model (12) is used to lock second segment number model (6) and third segment number model (7), then design hoisting structure number model (14) and demoulding structure number model (15), hoisting structure number model (14) is used to connect with hoisting equipment when hoisting, demoulding structure number model (15) is used to connect with lifting equipment when demoulding; Layer segmentation: utilize three-dimensional software to segment first segment number model (5), second segment number model (6) and third segment number model (7) into a plurality of layering plate number models (16) arranged in sequence along height direction, and lay out processing allowance on the basis of layering plate number model (16), obtain a plurality of blanking plate number models (17); Plate blanking: produce a plurality of blanking plate entities according to blanking plate number model (17) by blanking machine, and produce internal cavity movable block entity, external movable block entity, first locking structure entity, second locking structure entity, hoisting structure entity and demoulding structure entity according to the design of internal cavity movable block number model (3), external movable block number model (4), first locking structure number model (11), second locking structure number model (12), hoisting structure number model (14) and demoulding structure number model (15) by machining mode; Production blank: stack and glue a plurality of blanking plate entities to form first segment blank corresponding to first segment number model (5), second segment blank corresponding to second segment number model (6) and third segment blank corresponding to third segment number model (7); Blank processing: utilize three-axis woodworking numerical control machine tool (20) to process first segment blank, second segment blank and third segment blank respectively, obtain first segment entity, second segment entity and third segment entity, then utilize three-axis woodworking numerical control machine tool (20) to process internal cavity movable block entity and external movable block entity; Main body assembly: stack second segment entity on first segment entity, then lock first segment entity and second segment entity using first locking structure entity, then stack third segment entity on second segment entity, then lock second segment entity and third segment entity using second locking structure entity, obtain main body entity, install hoisting structure entity on third segment entity, obtain main body standard entity. ​ Subsequent processing and detection: first, the main body of the standard entity, the inner cavity of the entity and the external entity are surface treated, and then the inner cavity of the entity and the external entity are installed on the main body of the standard entity to obtain a standard mold entity, and then the standard mold entity is surface treated, and then three-dimensional detection is performed by using a three-dimensional detection instrument to judge the size accuracy of the standard mold entity; First, the main body of the standard entity and the external entity are hung on the sand box bottom plate, and the sand box is placed around, and the main body of the standard entity and the external entity are completely covered by filling the resin sand around the main body of the standard entity and the external entity, and the lower box sand mold is formed after the sand mold is completely solidified, and the lower box sand mold is obtained; Then, the lower box sand mold and the main body of the standard entity and the external entity are turned over 180°, the middle surface (19) of the main body of the standard entity and the inner cavity profile are completely upward, all the inner cavity of the entity and the riser mold are assembled on the main body of the standard entity, the parting surface is sleeved with a special sand box, and all the main body of the standard entity, the inner cavity of the entity, the external entity and the riser mold are completely covered by filling the resin sand, and the upper box sand mold is formed after the sand mold is solidified, and the upper box sand mold is obtained.

2. The method of manufacturing a sand mold for a steam turbine high-pressure cylinder according to claim 1, characterized by, In the standard mold design step: The designed standard mold number model (1) is proportional to the high-pressure cylinder of the steam turbine at a ratio of 1:

1.

3. The method of manufacturing a sand mold for a steam turbine high-pressure cylinder according to Claim 1, characterized by, The standard mold number model (1) has a flange, and the specific segmentation method of the segmented segmentation step is: A first segmentation surface is arranged at one-half of the height of the flange or more, and a second segmentation surface is arranged at a position d above the first segmentation surface, wherein d≤550mm; The part between the middle surface (19) and the first segmentation surface constitutes a first segment number model (5), the part between the first segmentation surface and the second segmentation surface constitutes a second segment number model (6), and the part above the second segmentation surface constitutes a third segment number model (7).

4. The method of manufacturing a sand mold for a steam turbine high-pressure cylinder according to Claim 1, characterized by, In the design of locking member and lifting member step: The first locking structure number model (11) is designed to include a stud (111) and a locking nut (112), a steel plate (113) is arranged at one end of the stud (111), the stud (111) is sequentially threaded through the second segment number model (6) and the first segment number model (5) and is screwed with the locking nut (112), and the locking nut (112) and the steel plate (113) are used to clamp the first segment number model (5) and the second segment number model (6) from the outside; The second locking structure number model (12) is designed to include a main profiled steel belt (121) and a secondary profiled steel belt (122), the main profiled steel belt (121) is fixed to the third segment number model (7) and the second segment number model (6) by wooden screws, and the main profiled steel belt (121) is fixed to the steel plate (113) on the stud (111) and tightly binds the second segment number model (6) and the third segment number model (7) from the outside, and the secondary profiled steel belt (122) is also fixed to the third segment number model (7) and the second segment number model (6) by wooden screws to tension the second segment number model (6) and the third segment number model (7). The hoisting structure numerical model (14) is designed to include an end plate (142), a pressing plate (143), and a hoisting rod (141) with a hoisting hole. The end plate (142) is fixed at the bottom end of the hoisting rod (141), the hoisting rod (141) penetrates the third section numerical model (7) from bottom to top, and the hoisting hole extends above the third section numerical model (7). Then the pressing plate (143) is fixed at the middle of the hoisting rod (141) and below the hoisting hole. The pressing plate (143) and the end plate (142) clamp the third section numerical model (7). The main conformable steel belt (121) is fixed with the pressing plate (143), and the secondary conformable steel belt (122) includes a connecting steel belt corresponding to the inside and outside of the main conformable steel belt (121), and the connecting steel belt is fixed with the end plate (142); The demolding structure numerical model (15) is designed to include a U-shaped rod (151) and a connecting nut (152) fixed at the opening of the U-shaped rod (151). When demolding is needed, the connecting nut (152) is screwed with the threaded stud (111), and the locking nut (112) is located between the connecting nut (152) and the steel plate (113).

5. The method of manufacturing a sand mold for a steam turbine high-pressure cylinder according to Claim 1, characterized by, In the layering and segmentation step: The first section numerical model (5) is segmented into multiple 25mm-thick layered plate numerical models (16) according to the horizontal equal-height layering method. The second section numerical model (6) is also segmented into multiple 25mm-thick layered plate numerical models (16) according to the horizontal equal-height layering method. The third section numerical model (7) is also segmented into multiple 25mm-thick layered plate numerical models (16) according to the horizontal equal-height layering method. When obtaining the blank plate numerical model (17) from the layered plate numerical model (16), the processing allowance is 15-20mm, and the generated blank plate numerical model (17) is in a frame-shaped structure.

6. The method of manufacturing a sand mold for a steam turbine high-pressure cylinder according to Claim 1, characterized by, In the plate blanking step: Before cutting, the cutting plate numerical model (17) is divided into a plurality of single plate numerical models (18) connected end to end by using three-dimensional software. The cutting process specifically includes using a cutting machine to process a plurality of standard plates with a size of 2440 1220 25 mm into single plate entities corresponding to the single plate numerical models (18). The method of obtaining the blank plate entity is to splice several single plate entities end to end into a frame-shaped blank plate entity, forming a joint between the single plate entities.

7. The method of manufacturing a sand mold for a steam turbine high-pressure cylinder according to claim 6, characterized by, In the production blank step: The joints of the upper and lower stacked blank plate entities are staggered.

8. The method of manufacturing a sand mold for a steam turbine high-pressure cylinder according to Claim 1, characterized by, In the blank processing step: When the first section blank is processed into a first section entity, first use the three-axis woodworking numerical control machine tool (20) to process the outer contour of the first section entity, then flip the first section blank by 180° and process the inner contour of the first section entity. The coordinate reference of the inner contour and the outer contour is coincident during processing; When the second section blank is processed into a second section entity, first use the three-axis woodworking numerical control machine tool (20) to process the outer contour of the second section entity, then flip the second section blank by 180° and process the inner contour of the second section entity. The coordinate reference of the inner contour and the outer contour is coincident during processing; When the third section blank is processed into a third section entity, first use the three-axis woodworking numerical control machine tool (20) to process the outer contour of the third section entity, then flip the third section blank by 180° and process the inner contour of the third section entity. The coordinate reference of the inner contour and the outer contour is coincident during processing.

9. The method of manufacturing a sand mold for a steam turbine high-pressure cylinder according to Claim 1, characterized by, In the main body assembly step: The specific way of assembling the second section entity on the first section entity is to stack the second section entity on the first section entity, then check the size, adjust the size if it is not correct, until the size is correct, then mark the second section entity, lift the second section entity, brush the latex on the joint surface of the first section entity, then lift the second section entity to the joint surface of the first section entity, bond the second section entity on the first section entity by the latex, and then lock the second section entity and the first section entity by the first locking structure entity; The specific way of assembling the third section entity on the second section entity is to stack the third section entity on the second section entity, then check the size, adjust the size if it is not correct, until the size is correct, then mark the third section entity, lift the third section entity, brush the latex on the joint surface of the second section entity, then lift the third section entity to the joint surface of the second section entity, bond the third section entity on the second section entity by the latex, and then lock the third section entity and the second section entity by the second locking structure entity.

10. The method of manufacturing a sand mold for a steam turbine high-pressure cylinder according to claim 9, characterized by, In the subsequent processing and detection steps: The surface treatment of the main standard entity, the inner cavity movable block entity and the external movable block entity is to scrape a layer of putty on the outer surface of the main standard entity, the inner cavity movable block entity and the external movable block entity, and then polish the surface.

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