Method of manufacturing a cast steel spiral

Abstract

The application discloses a manufacturing method of cast steel spiral belt and belongs to the field of cast steel part processing. The method comprises the following steps: S1, manufacturing a mold plate mold; S2, molding and closing a box; S3, smelting and pouring molten steel; S4, cleaning a cast part; S5, annealing treatment; S6, drilling; S7, inspection and warehousing. The application can prepare high-precision cast steel spiral belt by improving a casting molding method, and solves corresponding problems generated when spiral belts are prepared by pressing molding and casting molding.

Description

Technical Field

[0001] This invention belongs to the field of cast steel parts processing, and more specifically, relates to a method for manufacturing cast steel threaded ribbons. Background Technology

[0002] Ribbon is a long, twisted, thin-walled cast steel component, such as... Figure 1 and Figure 2 The spiral ribbon shown is an important component of a ribbon mixer. Each mixer will install four ribbons of the same size but opposite directions: two left-handed and two right-handed. In actual manufacturing, the ribbon has strict requirements regarding dimensional parameters such as cross-section and the base circle of the inner and outer bare wires. Furthermore, each mounting hole must be perpendicular to the tangential plane at that hole's location; otherwise, it is difficult to install the mixing blades.

[0003] In the prior art, methods for manufacturing spiral ribbons include pressing steel strips into a spiral structure and obtaining spiral ribbons through casting, with pressing forming being the more common method.

[0004] For example, Chinese patent application number CN202010530235.7, published on September 15, 2020, discloses a steel strip processing equipment and its processing technology for steel strip reinforced spiral corrugated pipes. The equipment includes a frame and a cutting assembly mounted on the frame. The cutting assembly includes at least one blade slidably connected to the frame, a first motor for rotating the blade, and a first drive cylinder for sliding the first motor. The cutting direction of the blade is parallel to the surface of the steel strip, and the angle between the cutting direction of the blade and the conveying direction of the steel strip is greater than 0° and less than 90°. During operation, the ends of new and old steel strips are cut at the same angle, resulting in an angle between the formed cutting surface and the conveying direction of the steel strip greater than 0° and less than 90°. The cut surfaces of the two steel strips are then welded together.

[0005] For example, Chinese patent application number CN202010305629.2, published on July 10, 2020, discloses a rolling grass knife strip twisting and forming machine and method thereof, belonging to the field of rolling grass knife processing. This twisting and forming machine includes a side-bending device and a planar twisting device. The side-bending device is used to bend the side of the blade, while the planar twisting device mainly bends the plane of the blade. The two work together to produce rolling grass knife strips.

[0006] Both of the above methods involve pressing to produce threaded ribbons. However, pressing exerts significant pressure on the steel strip during the forming process, potentially causing deformation or surface damage. This method is unsuitable for producing threaded ribbons with high precision requirements. Therefore, casting is generally used to produce threaded ribbons with high precision. However, when using casting to manufacture threaded ribbons, the following issues often need to be considered: (1) The ribbon blank is obtained by casting. When designing and manufacturing the mold, three points must be considered: A. Ensure that the molding operation is convenient and minimize or avoid the use of sand-dig molding. Although sand-dig molding is a common molding method for curved parting castings, it is not only inefficient but also prone to defects such as excessive or insufficient material, sand loss, and local thickness defects in the casting. B. Due to the long length of the ribbon, if the ribbon body is made into a whole mold, it will not only be prone to damage, low strength, and easy deformation, affecting the accuracy of the casting, but also make the molding operation and mold making more difficult. If it is made in sections, it is necessary to ensure that the position of each section is stable and that it does not deform during the molding process, thereby ensuring that the mold size and casting size are qualified, which greatly increases the manufacturing difficulty. C. It is necessary to ensure that the mold structure is sturdy and that the mold is not easily damaged.

[0007] (2) A reasonable casting process must be designed to prevent defects such as cracks, cold shuts, incomplete filling, and deformation of the ribbon casting, which is a thin-walled steel casting, during the casting process.

[0008] (3) Reasonable measures must be taken during heat treatment to prevent the casting from deforming during the heat treatment process.

[0009] (4) If the mounting holes are directly cast using the core-casting method, the local strength of the casting will be reduced, which may lead to deformation during casting and heat treatment. Furthermore, since the orientation of each mounting hole relative to a selected parting plane is different, the difficulty in making the mold core and the core-casting operation during molding are both greater, which may easily cause the defect of core misalignment. Therefore, the mounting holes can be made by drilling, but the problem of marking and positioning the mounting holes needs to be solved. Summary of the Invention

[0010] 1. The problem to be solved To address the problem that existing technologies struggle to produce high-precision spiral ribbons, this invention provides a method for manufacturing cast steel spiral ribbons. By improving the casting process, high-precision cast steel spiral ribbons can be produced, solving the problems encountered when preparing spiral ribbons through pressing and casting.

[0011] 2. Technical Solution To solve the above problems, the present invention adopts the following technical solution.

[0012] A method for manufacturing cast steel threaded strips includes the following steps: S1: Making the template mold S2: Styling and Packaging Manufacture upper box sand mold, lower box sand mold and dam-type pouring cup sand mold. Set a necked heat-insulating riser in the upper box sand mold. After demolding, brush zircon powder coating on the cavity surface and then close the box. S3: Steel smelting and casting The raw materials are added to the medium-frequency induction furnace for melting. After all the raw materials have been melted, the content of each element in the molten steel is detected and adjusted to the set ratio. Then the molten steel is poured into the ladle and poured into the sand mold of the dam-type pouring cup. S4: Casting Cleaning After the casting cools, the sand is removed, the casting is taken out, the surface molding sand is removed, the riser is knocked off, and the root of the riser and the seam are ground. S5: Annealing treatment S6: Drilling Using a scribing template and a hard punch, a positioning hole is punched out on the threaded surface of the threaded ribbon. Then, the threaded ribbon is placed on a drilling machine to drill the mounting hole. S7: Inspect and put into storage to obtain the required castings.

[0013] As a further improvement to the technical solution, the mold plate includes an iron frame and a base plate mounted on the iron frame. A pad is provided on the base plate, and a threaded mounting surface is mounted on the pad. The threaded mounting surface is equipped with interconnected movable blocks one, two, three and four that match the shape of the threaded strip.

[0014] As a further improvement to the technical solution, a riser pad is provided on the movable block to accommodate a necked-down heat-insulating riser.

[0015] As a further improvement to the technical solution, step S2 specifically includes the following steps: S21: Prepare resin sand using 40 / 70 mesh silica sand, resin and resin curing agent, and mix them evenly at a mass ratio of 100:(1.0~1.6):(0.5~0.8); S22: Place the lower sand box on the assembled mold plate, put in the resin sand and tamp it down, then scrape the surface of the sand box flat; S23: After the molding sand hardens, turn the lower sand box over, remove the mold, remove the mold plate, and then remove loose block one, loose block two, loose block three and loose block four and place them in the original position of the lower sand box. Place a necking and heat-insulating riser at the riser pad on loose block one. S24: Place the upper sand box on the lower sand box, put in the resin sand and tamp it down, and remove the molding sand above the necking insulation riser to make it an open riser, and then scrape the surface of the sand box flat. S25: After the molding sand hardens, turn it over and lift the upper sand box to remove the mold, and remove loose blocks one, two, three and four. S26: Blow away the loose sand from the surface of the sand mold in the lower and upper sand boxes respectively, then brush alcohol-based zircon powder coating on the surface of the cavity and ignite it; S27: Close the lower sand box and the upper sand box together and lock them with the box clamps; S28: Use resin sand and refractory bricks to make a dam-type pouring cup sand mold. After completion, brush alcohol-based zircon powder coating on the surface of the mold cavity and ignite it. Then place it on the upper sand box and align its pouring gate with the center of the necking insulation riser. S29: Lift the end of the assembled sand box near the necking insulation riser and use shims to support it, tilting the sand box at an 8-10 degree angle, and wait for pouring.

[0016] As a further improvement to the technical solution, step S3 specifically includes the following steps: S31: Steel is smelted using a medium-frequency induction furnace. Raw materials are added to the induction furnace in sequence for melting. After all the raw materials have melted, the content of each element in the molten steel is detected and adjusted to the set ratio. Then the molten steel is poured into a ladle for casting. S32: When pouring, align the ladle with the sand mold of the dam-type pouring cup. The molten steel is first poured into the sand mold of the dam-type pouring cup, then flows into the necking and heat-insulating riser, and then into the cavity of the mold. S33: The pouring temperature is 1550~1580℃, the mass of molten steel poured in each box is 60kg, and the pouring time is 10~20 seconds; S34: Release the box clamp 1 hour after the pouring is completed, and the sand will fall off 24 hours later.

[0017] As a further improvement to the technical solution, step S5 includes: assembling multiple cast parts on an annealing fixture, separating the casting parts with steel objects, and sealing the casting parts and the annealing fixture with steel plates, placing them in a heating furnace, heating them to 820-840°C, holding them at that temperature for 2 hours, cooling them to 350°C with the heating furnace, and then air-cooling them after removing them from the heating furnace.

[0018] As a further improvement to the technical solution, the annealing fixture includes a base and a cylindrical pad mounted on the base, with baffle one and baffle two mounted on the cylindrical pad.

[0019] As a further improvement to the technical solution, step S5 specifically includes the following steps: S51: First, place the first threaded casting on the annealing fixture, so that its inner spiral side fits against the cylindrical surface of the cylindrical pad, and then press it against the baffle. S52: Place the second threaded ribbon casting on the annealing fixture, so that its inner spiral side is in contact with the cylindrical surface of the cylindrical pad, and then bring it close to the first threaded ribbon casting. Use a T-shaped round steel to separate the two castings and make the T-shaped round steel close to the threaded ribbon casting. S53: Repeat the previous step until the set number of a set of ribbon castings are loaded; S54: Steel plates are used to tightly seal the space between the first threaded ribbon casting and the first baffle, and between the last threaded ribbon casting and the second baffle. S55: Place the assembled annealing fixture into the heating furnace, heat it to 820-840℃, hold it at that temperature for 2 hours, then cool it to 350℃ with the heating furnace, and remove it from the heating furnace for air cooling.

[0020] As a further improvement to the technical solution, the scribing template includes a screw-face base plate, a first reference surface, a second reference surface, and a second positioning hole; the surface of the screw-face base plate is one-quarter of the screw surface of the screw ribbon casting; the second positioning hole is a cylindrical through hole, which is set on the screw-face base plate and corresponds to the position of the mounting hole set on the screw ribbon casting.

[0021] As a further improvement to the technical solution, step S6 specifically includes the following steps: S61: First, use the scribing template to check whether the surface of the screw base plate is in contact with the screw surface of the screw ribbon, and whether the screw ribbon can be divided into four equal parts using reference surface one and reference surface two. If so, proceed to the next step. S62: Place the scribing template on the threaded ribbon casting, so that the surface of its threaded base plate is in contact with the surface of the threaded ribbon casting, and the plane of the first reference surface is in the same plane as the radial end face of the threaded ribbon. S63: Draw a straight line at the intersection of the reference plane two and the threaded surface of the threaded casting, insert a hard punch into the second positioning hole and tap it to create a positioning hole recess; S64: Align the first reference plane with the first line. Draw the second line at the intersection of the second reference plane and the threaded surface of the threaded casting. Then, use a hard punch to insert into the two second positioning holes and tap them to create two positioning hole recesses. S65: Align the reference plane one with the line two, use the reference plane two to draw the line three on the screw surface, then insert a hard punch into the second positioning hole and tap it to create a positioning hole recess. S66: Align the first reference surface with the three straight lines, and check whether the second reference surface is on the same plane as the radial end face of the threaded ribbon. If so, insert a hard punch into the second positioning hole and tap it to create a positioning hole recess. S67: Place the threaded cable on the drilling machine, place the positioning hole to be drilled in the center of the drilling machine table, use a steel plate to support it so that the positioning hole is in a horizontal position, and then drill the mounting hole of the threaded cable in the center of the positioning hole. S68: Repeat the previous step until all mounting holes are machined.

[0022] 3. Beneficial effects Compared with existing technologies, the present invention provides a method for manufacturing cast steel threaded ribbons. By improving the casting process and combining a unique structural design of devices such as mold plates, sand molds, annealing fixtures, and scribing templates, it is possible to produce high-precision cast steel threaded ribbons and solve the corresponding problems that arise when preparing threaded ribbons through pressing and casting. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the main structure of a cast steel ribbon, illustrating a manufacturing method for cast steel ribbons. Figure 2 A top view schematic diagram of a method for manufacturing cast steel threaded ribbon; Figure 3 A schematic diagram of the main structure of a mold for manufacturing a cast steel threaded strip; Figure 4 A bottom view schematic diagram of the mold structure for a method of manufacturing cast steel threaded strips; Figure 5 This is a right-side view of the mold structure for a method of manufacturing cast steel threaded strips. Figure 6 A schematic diagram of the isometric side view of a mold for manufacturing a cast steel threaded strip; Figure 7 A schematic diagram of the main structure of a dam-type pouring cup sand mold for a method of manufacturing cast steel ribbon; Figure 8 A top view schematic diagram of the sand mold structure of the dam-type pouring cup for a method of manufacturing cast steel ribbon; Figure 9 This is a schematic diagram of the main structure of an annealing fixture for a method of manufacturing cast steel threaded ribbon; Figure 10 A top view schematic diagram of an annealing fixture for a method of manufacturing cast steel threaded ribbon; Figure 11 A schematic diagram of the left side of an annealing fixture for a method of manufacturing cast steel ribbon; Figure 12 A schematic diagram of the main structure of a T-shaped round steel bar for a method of manufacturing cast steel ribbon; Figure 13 A schematic diagram of the main structure of a scribing template for a method of manufacturing cast steel threaded ribbon; Figure 14 A schematic diagram of the left-hand structure of a scribing template for a method of manufacturing cast steel threaded ribbon; Figure 15 This is a top view schematic diagram of a scribing template for a method of manufacturing cast steel threaded ribbon.

[0024] Explanation of the labels in the schematic diagram: 101, Loose Block 1; 102, Loose Block 2; 103, Loose Block 3; 104, Loose Block 4; 105, Iron Frame; 106, Base Plate; 107, Pad Plate; 108, First Positioning Pin; 109, Shim; 110, Threaded Mounting Surface; 111, Stop Block 1; 112, Stop Block 2; 113, Stop Block 3; 114, Loose Block Positioning Pin; 115, First Positioning Hole; 116, Riser Gasket; 401, Base; 402, Cylindrical Gasket; 403, Baffle 1; 404, Baffle 2; 405, Reinforcing Rib; 406, Lifting Lug; 601, Threaded Base Plate; 602, Reference Surface 1; 603, Reference Surface 2; 604, Second Positioning Hole; 605, Outer Stop Block; 606, Inner Stop Block. Detailed Implementation

[0025] Exemplary embodiments of the present invention are described in detail below. While these exemplary embodiments have been described in sufficient detail to enable those skilled in the art to practice the invention, it should be understood that other embodiments may be implemented and various changes may be made to the invention without departing from its spirit and scope. The more detailed description of embodiments of the invention below is not intended to limit the scope of the claimed invention, but is merely illustrative and does not limit the description of the features and characteristics of the invention, in order to suggest the best mode for carrying out the invention and to enable those skilled in the art to practice it. Therefore, the scope of the invention is defined only by the appended claims.

[0026] Example 1 A method for manufacturing cast steel threaded ribbon, used to manufacture such as Figure 1 and Figure 2 The cast steel threaded strip shown in the diagram should be noted that, as Figure 1 and Figure 2 The manufacturing method of this embodiment applies to cast steel ribbons with similar structures but different dimensional parameters and materials.

[0027] In this embodiment, the spiral material is ZG270-500, the part weighs 39kg, the cross-section is a 150mm×20mm rectangle, the outer spiral length is 1819mm, its spiral base circle radius is R613mm, the inner spiral length is 1557mm, its spiral base circle radius is R463mm, and the spiral surface is provided with eight mounting holes, which are φ22mm through holes. Each hole is perpendicular to the tangent plane at the hole position and is used to install four wear-resistant stirring blades.

[0028] The manufacturing method of this embodiment includes the following steps: S1: Mold Manufacturing Based on the ribbon drawing and casting process, fabricate the mold plate. Specifically, such as... Figures 3 to 6As shown, the mold plate includes an iron frame 105 and a base plate 106 mounted on the iron frame 105. A pad 107 is provided on the base plate 106, and a threaded mounting surface 110 is mounted on the pad 107. The threaded mounting surface 110 is fitted with interconnected movable blocks 101, 102, 103, and 104, which match the shape of the threaded band. Specifically, each of the movable blocks 101, 102, 103, and 104 has two first positioning holes 115, which are matched and connected to the movable block positioning pins 114 on the threaded mounting surface 110. In addition, the threaded mounting surface 110 is also provided with a stop block 111, a stop block 112, and a stop block 113. The mold plate is provided with a first positioning pin 108 and a shim 109 for convenient subsequent casting. A riser gasket 116 is also provided on the movable block 101 for placing the necking and insulating riser 3.

[0029] In this embodiment, the iron frame 105 of the mold plate is welded from six 80mm×80mm square steel bars, and a base plate 106 is set on the iron frame 105. The plane of the base plate 106 is the parting surface of the mold, and various components such as the mold pad 107, the first locating pin 108, and the shim 109 are set on the parting surface. The result of this parting surface setting is that the draft angles of the two radial end faces of the threaded ribbon relative to the parting surface are opposite, a part of the outer threaded side has a draft angle opposite to that of another part relative to the parting surface, and a part of the inner threaded side has a draft angle opposite to that of another part relative to the parting surface. This facilitates the setting of various components such as the threaded mounting surface 110, the movable block, and the stop block. In addition, the overall height of the mold is smaller, which helps to reduce the height of the sand box and save molding sand consumption.

[0030] Furthermore, in this embodiment, the radial end face two, a portion of the outer spiral side surface, and a portion of the inner spiral side surface of the spiral ribbon have a positive draft angle relative to the plane of the base plate 106, allowing for smooth demolding during the lower sand mold making process. The radial end face one, another portion of the outer spiral side surface, and another portion of the inner spiral side surface have a negative draft angle relative to the plane of the base plate 106. However, due to the isolation effect of the stop blocks 111, 112, and 113, they can also be smoothly demolded during the lower sand mold making process. When making the upper sand mold, the movable blocks 101, 102, 103, and 104 are placed in the original positions of the lower sand mold. The radial end face one, another portion of the outer spiral side surface, and another portion of the inner spiral side surface, which originally had a negative draft angle relative to the plane of the base plate 106, now have a positive draft angle relative to the plane of the upper sand mold, allowing for smooth demolding. Because the mold can be easily removed when manufacturing the lower and upper sand molds, the sand digging molding is effectively avoided, making the molding operation more convenient.

[0031] It is worth mentioning that the movable blocks 101, 102, 103, and 104 are placed on the threaded mounting surface 110. The bottom is positioned by the movable block positioning pin 114 and the first positioning hole 115, while the sides are fixed by the stop blocks 111, 112, and 113. The stable position of each movable block ensures that it does not deform during the molding process, thus guaranteeing the correct dimensions of the mold and the casting. The mold plate uses a steel frame 105 welded from six square steel bars as its base, and then a base plate 106, a pad plate 107, a first positioning pin 108, and a shim 109 are installed. The threaded mounting surface 110, movable blocks, and stop blocks are set on the pad plate 107, making the mold structure robust, the components less prone to damage, and able to withstand multiple molding operations, resulting in a long mold life.

[0032] S2: Styling and Packaging S21: Prepare resin sand using 40 / 70 mesh silica sand, resin and resin curing agent, and mix them evenly at a mass ratio of 100:(1.0~1.6):(0.5~0.8).

[0033] S22: Place the lower sand box on the assembled mold plate, put in the resin sand and tamp it down, then scrape the surface of the sand box flat.

[0034] S23: After the molding sand hardens, turn the lower sand box over, remove the mold, remove the mold plate, and then remove loose blocks 101, 102, 103 and 104 and place them in the original position of the lower sand box. Place a necking and heat-insulating riser at the riser gasket 116 on loose block 101.

[0035] S24: Place the upper sand box on the lower sand box, put in the resin sand and tamp it down, and remove the molding sand above the necking insulation riser to make it an open riser, and then scrape the surface of the sand box flat.

[0036] S25: After the molding sand hardens, turn it over and lift the upper sand box to remove the mold, and remove loose blocks 101, 102, 103 and 104.

[0037] S26: Blow away the loose sand from the surface of the sand mold in the lower and upper sand boxes respectively, and then brush the surface of the cavity with alcohol-based zircon powder coating and ignite it.

[0038] S27: Close the lower and upper sand boxes together and lock them with the box clamps.

[0039] S28: A dam-type pouring cup sand mold is made using resin sand and refractory bricks. After completion, an alcohol-based zircon powder coating is applied to the cavity surface and ignited. It is then placed on the upper sand box, with its pouring gate aligned with the center of the necking insulation riser. The structure of the dam-type pouring cup sand mold is as follows: Figure 7 and Figure 8As shown, it includes a pouring cup and a pouring gate located on both sides, with a dam on the side of the pouring gate and refractory bricks installed on top of the dam.

[0040] S29: Lift the end of the assembled sand box near the necking insulation riser and use shims to support it, tilting the sand box at an 8-10 degree angle, and wait for pouring.

[0041] S3: Steel smelting and casting S31: Steel is smelted using a medium-frequency induction furnace. Raw materials are added to the induction furnace in sequence for melting. After all the raw materials have melted, the content of each element in the molten steel is detected and adjusted to the set ratio. Then the molten steel is poured into a ladle for casting.

[0042] S32: When pouring, align the ladle with the dam-type pouring cup sand mold. The molten steel is first poured into the dam-type pouring cup sand mold, then flows into the necking and heat-insulating riser, and then into the mold cavity.

[0043] S33: The pouring temperature is 1550~1580℃, the mass of molten steel poured in each box is 60kg, and the pouring time is 10~20 seconds.

[0044] S34: Release the box clamp 1 hour after the pouring is completed, and the sand will fall off 24 hours later.

[0045] In this step, the molten steel comprises the following components by mass percentage: C≤0.40%, Si≤0.60%, Mn≤0.90%, P≤0.035%, S≤0.035%, with the remainder being iron and unavoidable impurities.

[0046] The gating system design in this embodiment does not use a conventional cast steel gating system because: First, the ribbon is a long, twisted, thin-walled part with a wall thickness of 20mm, and cracks are easily generated at the root of the gating gate; Second, the gating gates can interact with each other, as well as with the gating gate and the riser, causing partial shrinkage of the casting to be hindered, resulting in casting deformation.

[0047] The riser design in this embodiment uses a single necking insulating riser because: First, the ribbon wall thickness is 20mm, it is a plate-shaped part, and the shrinkage of the casting body is small, so the feeding effect of the riser is limited to feeding the early liquid shrinkage after pouring; Second, the necking insulating riser is provided with an easy-cut groove at the end where it connects to the riser gasket 116, so that the riser can be knocked off directly after pouring without damaging the casting itself, which can save the cost of riser removal; Third, if a multi-riser design is used, the risers can interact with each other, causing the shrinkage of some parts of the casting to be hindered, resulting in casting deformation.

[0048] The pouring cup design in this embodiment adopts a dam-type pouring cup sand mold, which serves two purposes: First, molten steel is poured into the pouring cup first, and then enters the mold cavity after passing through the dam-type sand mold, which can effectively play a role in slag blocking and reduce slag inclusion defects in the casting; Second, the flow rate of molten steel is greatly reduced by pouring it into the pouring cup first, and then entering the mold cavity after passing through the dam, which effectively reduces the impact of molten steel on the mold cavity.

[0049] S4: Casting Cleaning After the casting cools, the sand is removed, the casting is taken out, the surface molding sand is removed, the riser is knocked off, and the root of the riser and the seam are ground. S5: Annealing treatment S51: First, place the first threaded casting on the annealing fixture, ensuring its inner spiral side aligns with the cylindrical surface of the cylindrical pad 402, and then press it firmly against the baffle 403. In this step, if... Figure 9 and Figure 11 As shown, the annealing fixture 4 includes a base 401 and a cylindrical pad 402 mounted on the base 401. The cylindrical pad 402 is equipped with a first baffle 403 and a second baffle 404. The cylindrical pad 402 has a semi-cylindrical structure, and its surface matches the inner helical side of the ribbon casting. The cylindrical diameter of the cylindrical pad 402 is equal to the diameter of the inner helix base circle of the ribbon casting. The first baffle 403 and the second baffle 404 are used to limit the position of the ribbon casting placed on the cylindrical pad 402. Furthermore, a reinforcing rib 405 connects the cylindrical pad 402 and the baffle to improve the connection strength. The cylindrical pad 402 is also provided with lifting lugs 406 for lifting the annealing fixture 4.

[0050] S52: Place the second threaded ribbon casting on the annealing fixture, ensuring its inner spiral side aligns with the cylindrical surface of the cylindrical pad 402. Then, bring it close to the first threaded ribbon casting, separating the two castings with a clamping device such as... Figure 12 The T-shaped round steel bars are spaced apart and brought into close contact with the threaded ribbon casting.

[0051] S53: Repeat the previous step until the set number of set ribbon castings are loaded. In this embodiment, a set of ribbon castings consists of 8 pieces.

[0052] S54: Steel plates are used to tightly seal the space between the first threaded ribbon casting and baffle 403, and between the last threaded ribbon casting and baffle 404.

[0053] S55: Place the assembled annealing fixture into the heating furnace, heat it to 820-840℃, hold it at that temperature for 2 hours, then cool it to 350℃ with the heating furnace, and remove it from the heating furnace for air cooling.

[0054] S6: Drilling Using a scribing template and a hard punch, locating holes are punched into the threaded surface of the threaded ribbon. Then, the threaded ribbon is placed on a drilling machine to drill mounting holes. For example... Figures 13 to 15 As shown, the scribing template includes a threaded base plate 601, a first reference surface 602, a second reference surface 603, and a second positioning hole 604. The surface of the threaded base plate 601 is one-quarter of the threaded surface of the threaded ribbon casting. The second positioning hole 604 is a cylindrical through hole, which is provided on the threaded base plate 601 and corresponds to the position of the mounting hole set on the threaded ribbon casting. In this embodiment, there are two second positioning holes 604. In addition, the two sides of the threaded base plate 601 are respectively equipped with an outer stop block 605 and an inner stop block 606 to limit the movement of the threaded ribbon casting.

[0055] Specifically, the steps include the following: S61: First, use a scribing template to check whether the surface of the screw base plate 601 is in contact with the screw surface of the screw ribbon, and whether the screw ribbon can be divided into four equal parts using reference surface 1 602 and reference surface 2 603. If so, proceed to the next step.

[0056] S62: Place the scribing template on the ribbon casting, so that the surface of the ribbon base plate 601 is in contact with the surface of the ribbon casting, and the plane of the reference surface 602 is in the same plane as the radial end face of the ribbon.

[0057] S63: Draw a straight line at the intersection of the reference plane 603 and the threaded surface of the threaded casting, insert a hard punch into the second positioning hole 604 and tap it to create a positioning hole recess.

[0058] S64: Align the first reference surface 602 with the first line. Draw the second line at the intersection of the second reference surface 603 and the threaded surface of the threaded casting. Then, use a hard punch to insert into the two second positioning holes 604 and tap them to create two positioning hole recesses.

[0059] S65: Align the reference surface 602 with the straight line 2, use the reference surface 603 to draw the straight line 3 on the screw surface, then insert a hard punch into the second positioning hole 604 and tap it to create a positioning hole recess.

[0060] S66: Align the first reference surface 602 with the straight three-line scribe line, and check whether the second reference surface 603 is on the same plane as the radial end face of the second threaded ribbon. If so, insert a hard punch into the second positioning hole 604 and tap it to create a positioning hole recess.

[0061] S67: Place the threaded cable on the drilling machine, place the positioning hole to be drilled in the center of the drilling machine table, use a steel plate to support it so that the positioning hole is in a horizontal position, and then drill the mounting hole of the threaded cable in the center of the positioning hole.

[0062] S68: Repeat the previous step until all mounting holes are machined.

[0063] S7: Inspect and put into storage to obtain the required castings.

[0064] In summary, the method for manufacturing cast steel threaded ribbon in this embodiment, by improving the casting process and combining the unique structural design of devices such as mold plates, sand molds, annealing fixtures, and scribing templates, can produce high-precision cast steel threaded ribbons and solve the corresponding problems that arise when preparing threaded ribbons by pressing and casting.

[0065] The examples described herein are merely preferred embodiments of the invention and are not intended to limit the concept and scope of the invention. Any modifications and improvements made by those skilled in the art to the technical solutions of the invention without departing from the design concept of the invention should fall within the protection scope of the invention.

Claims

1. A method for manufacturing cast steel threaded ribbon, characterized in that: Includes the following steps: S1: Making the template mold S2: Styling and Packaging Manufacture upper box sand mold, lower box sand mold and dam-type pouring cup sand mold. Set a necked heat-insulating riser in the upper box sand mold. After demolding, brush zircon powder coating on the cavity surface and then close the box. S3: Steel smelting and casting The raw materials are added to the medium-frequency induction furnace for melting. After all the raw materials have been melted, the content of each element in the molten steel is detected and adjusted to the set ratio. Then the molten steel is poured into the ladle and poured into the sand mold of the dam-type pouring cup. S4: Casting Cleaning After the casting cools, the sand is removed, the casting is taken out, the surface molding sand is removed, the riser is knocked off, and the root of the riser and the seam are ground. S5: Annealing treatment S6: Drilling Using a scribing template and a hard punch, a positioning hole is punched out on the threaded surface of the threaded ribbon. Then, the threaded ribbon is placed on a drilling machine to drill the mounting hole. S7: Inspection and warehousing to obtain the required castings; The mold plate includes an iron frame (105) and a base plate (106) mounted on the iron frame (105). A pad (107) is provided on the base plate (106). A threaded mounting surface (110) is mounted on the pad (107). The threaded mounting surface (110) is equipped with interconnected movable blocks one (101), movable block two (102), movable block three (103) and movable block four (104) that match the shape of the threaded strip. A riser pad (116) is provided on the movable block (101) for placing a necked heat-insulating riser; The spiral mounting surface (110) is also provided with a first stop (111), a second stop (112), and a third stop (113). Due to the isolation effect of the first stop (111), the second stop (112), and the third stop (113), the mold can be successfully removed when making the lower box sand mold. Step S2 specifically includes the following steps: S21: Prepare resin sand using 40 / 70 mesh silica sand, resin and resin curing agent, and mix them evenly at a mass ratio of 100:(1.0~1.6):(0.5~0.8); S22: Place the lower sand box on the assembled mold plate, put in the resin sand and tamp it down, then scrape the surface of the sand box flat; S23: After the molding sand hardens, turn the lower sand box over, remove the mold, remove the mold plate, and then remove the first (101), the second (102), the third (103) and the fourth (104) loose blocks and place them in the original position of the lower sand box. Place a necking and heat-insulating riser at the riser gasket (116) on the first (101). S24: Place the upper sand box on the lower sand box, put in the resin sand and tamp it down, and remove the molding sand above the necking insulation riser to make it an open riser, and then scrape the surface of the sand box flat. S25: After the molding sand hardens, turn it over and lift the upper sand box to remove the mold, and take out the loose blocks one (101), two (102), three (103) and four (104); S26: Blow away the loose sand from the surface of the sand mold in the lower and upper sand boxes respectively, then brush alcohol-based zircon powder coating on the surface of the cavity and ignite it; S27: Close the lower sand box and the upper sand box together and lock them with the box clamps; S28: Use resin sand and refractory bricks to make a dam-type pouring cup sand mold. After completion, brush alcohol-based zircon powder coating on the surface of the mold cavity and ignite it. Then place it on the upper sand box and align its pouring gate with the center of the necking insulation riser. S29: Lift the end of the assembled sand box near the necking insulation riser and use shims to support it, tilting the sand box at an 8-10 degree angle, and wait for pouring.

2. The method for manufacturing a cast steel threaded strip according to claim 1, characterized in that: Step S3 specifically includes the following steps: S31: Steel is smelted using a medium-frequency induction furnace. Raw materials are added to the induction furnace in sequence for melting. After all the raw materials have melted, the content of each element in the molten steel is detected and adjusted to the set ratio. Then the molten steel is poured into a ladle for casting. S32: When pouring, align the ladle with the sand mold of the dam-type pouring cup. The molten steel is first poured into the sand mold of the dam-type pouring cup, then flows into the necking and heat-insulating riser, and then into the cavity of the mold. S33: The pouring temperature is 1550~1580℃, the mass of molten steel poured in each box is 60kg, and the pouring time is 10~20 seconds; S34: Release the box clamp 1 hour after the pouring is completed, and the sand will fall off 24 hours later.

3. The method for manufacturing a cast steel threaded strip according to claim 1, characterized in that: Step S5 includes: assembling multiple cast castings on an annealing fixture, separating the castings with steel objects, and sealing the castings and annealing fixture with steel plates, placing them in a heating furnace, heating to 820-840°C, holding at that temperature for 2 hours, cooling to 350°C with the heating furnace, and then air-cooling them after removing them from the heating furnace.

4. The method for manufacturing a cast steel threaded strip according to claim 3, characterized in that: The annealing fixture includes a base (401) and a cylindrical pad (402) mounted on the base (401). The cylindrical pad (402) is equipped with a first baffle (403) and a second baffle (404).

5. The method for manufacturing a cast steel threaded strip according to claim 4, characterized in that: Step S5 specifically includes the following steps: S51: First, place the first threaded casting on the annealing fixture so that its inner spiral side fits against the cylindrical surface of the cylindrical pad (402), and then press it against the baffle (403). S52: Place the second threaded ribbon casting on the annealing fixture, so that its inner spiral side is in contact with the cylindrical surface of the cylindrical pad (402), and then bring it close to the first threaded ribbon casting. Use a T-shaped round steel to separate the two castings and make the T-shaped round steel close to the threaded ribbon casting. S53: Repeat the previous step until the set number of a set of ribbon castings are loaded; S54: Steel plates are used to seal the first threaded casting between the first threaded casting and the first baffle (403), and between the last threaded casting and the second baffle (404); S55: Place the assembled annealing fixture into the heating furnace, heat it to 820-840℃, hold it at that temperature for 2 hours, then cool it to 350℃ with the heating furnace, and remove it from the heating furnace for air cooling.

6. The method for manufacturing a cast steel threaded strip according to claim 1, characterized in that: The scribing template includes a screw-face base plate (601), a first reference surface (602), a second reference surface (603), and a second positioning hole (604); the surface of the screw-face base plate (601) is a quarter of the screw surface of the screw ribbon casting; the second positioning hole (604) is a cylindrical through hole, which is set on the screw-face base plate (601) and corresponds to the position of the mounting hole set on the screw ribbon casting.

7. The method for manufacturing a cast steel threaded strip according to claim 6, characterized in that: Step S6 specifically includes the following steps: S61: First, use the scribing template to check whether the surface of its screw base plate (601) is in contact with the screw surface of the screw ribbon, and whether the screw ribbon can be divided into four equal parts using reference surface one (602) and reference surface two (603). If so, proceed to the next step. S62: Place the scribing template (6) on the ribbon casting so that the surface of its spiral base plate (601) is in contact with the surface of the ribbon casting, so that the plane of the reference surface (602) is in the same plane as the radial end face of the ribbon. S63: Draw a straight line at the intersection of the reference plane two (603) and the threaded surface of the threaded casting, insert a hard punch into the second positioning hole (604) and tap it to create a positioning hole recess; S64: Align the first reference surface (602) with the first line, draw the second line at the intersection of the second reference surface (603) and the threaded surface of the threaded casting, and then insert the hard punch into the two second positioning holes (604) one after another and knock them to make two positioning hole recesses. S65: Align the reference surface one (602) with the straight line two, use the reference surface two (603) to draw the straight line three on the screw surface, then insert a hard punch into the second positioning hole (604) and tap it to make a positioning hole recess; S66: Align the first reference surface (602) with the straight three-line scribe line, check whether the second reference surface (603) is in the same plane as the radial end face of the threaded ribbon. If so, insert a hard punch into the second positioning hole (604) and tap it to create a positioning hole recess. S67: Place the threaded cable on the drilling machine, place the positioning hole to be drilled in the center of the drilling machine table, use a steel plate to support it so that the positioning hole is in a horizontal position, and then drill the mounting hole of the threaded cable in the center of the positioning hole. S68: Repeat the previous step until all mounting holes are machined.

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