Wax modeling method for multi-joint turbine guide vanes

Abstract

The present invention relates to a wax mold forming method for a multi-joint turbine guide vane, comprising the following steps: S1, splitting the multi-joint turbine guide vane into two sets of structures, one set is a blade group, and the other set is an edge plate group; S2, the two sets of structures are respectively pressed by corresponding molds, mold A presses the blade group, and mold B presses the edge plate group; S3, welding is performed by welding tooling; S3-1, the blades pressed by mold A are placed on the bottom plate in sequence; S3-2, the edge plate pressed by mold B is placed on the upper part of the bottom plate, and the outer positioning block of the welding tooling is against the edge plate located at the upper part of the workpiece; the inner positioning device of the welding tooling is against the edge plate located at the lower part of the workpiece; S3-3, tightening the second screw on the cover plate, and the cover plate presses the blade; S3-4, connecting each welding seam by an electric soldering iron. The present invention splits the multi-joint blade into a plurality of blades and edge plate structures for welding, and develops products with qualified size and high surface quality at low cost and high efficiency.

Description

Technical Field

[0001] The invention relates to a wax mold forming method for multiple turbine guide vanes, belonging to the field of investment casting. Background Art

[0002] With the development of science and technology, the blades required for turbine guide vanes have gradually changed from single-joint blades to multi-joint blades, and the difficulty of blade size has also gradually increased. Existing multi-joint blades are generally molded as a whole, which has the following disadvantages:

[0003] 1. The overall mold opening results in a relatively large mold, many live blocks, poor surface quality, high mold costs, and subsequent wax molds and castings require more time for surface smoothing;

[0004] 2. Due to the difference in thickness of each area of ​​the overall mold, it is difficult to accurately design the dimensional shrinkage rate, especially the throat size between the blades and the flow channel size between the edge plates.

[0005] 3. Subsequent size adjustments are also difficult, and it is likely that the mold will need to be reopened, which will take a long time to develop. Summary of the invention

[0006] The purpose of the present invention is to overcome the above-mentioned shortcomings and provide a wax mold forming method for multiple turbine guide vanes.

[0007] The object of the present invention is achieved in that:

[0008] A wax mold forming method for multiple turbine guide vanes is characterized by comprising the following steps:

[0009] S1. Split the multi-unit turbine guide vanes into two sets of structures, one set is a blade group, and the other set is a lip plate group;

[0010] S2. The two sets of structures are pressed using corresponding molds respectively, mold A presses the blade group, and mold B presses the edge plate group;

[0011] S3, use welding tooling for welding;

[0012] S3-1, placing the leaves pressed by mold A on the bottom plate one by one;

[0013] S3-2, the edge plate pressed by the mold B is placed on the upper part of the bottom plate, the outer positioning block of the welding fixture is against the edge plate located at the upper part of the workpiece; the inner positioning device of the welding fixture is against the edge plate located at the lower part of the workpiece;

[0014] S3-3, tighten the second screw on the cover plate, and the cover plate presses the blades;

[0015] S3-4. Connect each weld seam using an electric soldering iron.

[0016] Further, the welding fixture includes a second screw, an outer positioning block, an inner positioning device, a cover plate and a bottom plate;

[0017] The outer positioning block is fixedly arranged on the upper part of the bottom plate, and the outer positioning block presses the edge plate on the upper part of the workpiece;

[0018] The inner positioning device comprises a first screw, a first fixed block, a second fixed block, a third fixed block and a push plate. The first fixed block, the second fixed block and the third fixed block are arranged on the bottom plate. The first screw passes through the first fixed block and is fixedly connected with the push plate. Both sides of the push plate are slidably arranged on the second fixed block and the third fixed block respectively. Under the action of the first screw, the upper end of the push plate presses the edge plate at the lower part of the workpiece.

[0019] The two ends of the cover plate are fixedly connected to the bottom plate, the second screw rod is arranged on the cover plate, the second screw rod corresponds to the blades one by one, and the cover plate presses the blades.

[0020] Furthermore, after welding, the parts are inspected by 3D scanner.

[0021] Furthermore, there are three external positioning blocks.

[0022] Furthermore, anti-skid feet are provided at the bottom of the base plate.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] 1. Compared with the traditional overall mold opening scheme, the blade is split into molds according to the structure, which reduces the size of the mold, reduces the complexity of the mold, and thus reduces the mold cost;

[0025] 2. Compared with the traditional overall mold opening scheme, after the blade is split into molds according to the structure, a large number of movable block structures are avoided, the parting area is small, the surface quality is high, and the workload of wax mold and casting surface smoothing is further reduced;

[0026] 3. After the mold is split, the mold repair can be carried out separately without interfering with each other, reducing the risk of mold repair;

[0027] 4. After splitting the mold, the wax mold structure of each block is single, the difficulty of shrinkage design is reduced, and the mold opening success rate is higher;

[0028] 5. Some dimensions can be adjusted by welding fixtures, such as position, torsion angle and other dimensions, thus avoiding the need to repair the main mold.

[0029] The invention discloses a wax mold forming method for a multi-joint turbine guide vane. By optimizing the wax mold forming scheme, that is, optimizing the wax mold mold and tooling design scheme, the multi-joint blades are split into multiple blades and edge plate structures for welding, so as to develop a product with qualified size and high surface quality at a relatively low cost and high efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is a schematic diagram of a seven-unit turbine guide blade according to the present invention.

[0031] Figure 2 It is a schematic diagram of a welding tool of the present invention.

[0032] In the figure:

[0033] First blade group 1, second blade group 2, third blade group 3, first edge plate 4, second edge plate 5, third edge plate 6, welding fixture 7, first screw 7.1, second screw 7.2, outer positioning block 7.3, inner positioning device 7.4, cover plate 7.5, bottom plate 7.6, first fixing block 7.7, second fixing block 7.8, third fixing block 7.9, push plate 7.10. DETAILED DESCRIPTION

[0034] The specific implementation of the present invention is further described below in conjunction with the accompanying drawings and embodiments. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and cannot be used to limit the protection scope of the present invention.

[0035] See also Figure 1 Taking a seven-unit turbine guide blade as an example, the maximum outline size is: 48mm*268mm*164mm, the casting material is high-temperature alloy K477, the minimum wall thickness is 2mm, the blade profile tolerance is only ±0.15mm, the blade position requirement is ±0.2mm, and the size requirements are relatively high.

[0036] Figure 1 The seven-unit turbine guide blades are divided into two sets of structures, one set is the first blade group 1, the second blade group 2 and the third blade group 3, and the other set is the first edge plate 4, the second edge plate 5 and the third edge plate 6.

[0037] The two sets of structures are pressed using corresponding molds respectively. Mold A presses the first blade group 1, the second blade group 2 and the third blade group 3, wherein the first blade group 1 includes one blade, the second blade group 2 includes five blades, and the third blade group 3 includes one blade; mold B presses the first edge plate 4, the second edge plate 5 and the third edge plate 6.

[0038] After the mold is pressed and formed, a special welding tool is used for welding. The specific steps are as follows:

[0039] 1. Place the seven leaves pressed by mold A on the bottom plate 7.6 in sequence;

[0040] 2. Place the first edge plate 4 and the second edge plate 5 pressed by the mold B on the upper part of the bottom plate 7.6, and the outer positioning block 7.3 abuts against the first edge plate 4 and the second edge plate 5; place the third edge plate 6 pressed by the mold B on the lower part of the bottom plate 7.6, and under the action of the first screw 7.1, the upper end of the push plate 7.10 presses the third edge plate 6, and at the same time, the outer positioning block 7.3 presses the first edge plate 4 and the second edge plate 5;

[0041] 3. Tighten the second screw 7.2 on the cover plate 7.5, and the cover plate 7.5 presses the blades;

[0042] 4. Use an electric soldering iron to connect each weld seam.

[0043] 5. After welding, use a 3D scanner to inspect to ensure that the wax model meets the model contour requirements.

[0044] See also Figure 2 The welding fixture 7 comprises a second screw 7.2, an outer positioning block 7.3, an inner positioning device 7.4, a cover plate 7.5 and a bottom plate 7.6.

[0045] The outer positioning block 7.3 is fixedly arranged on the upper part of the bottom plate 7.6, and the outer positioning block 7.3 presses the first edge plate 4 and the second edge plate 5 to prevent them from moving on the X and Y axes.

[0046] The inner positioning device 7.4 comprises a first screw rod 7.1, a first fixed block 7.7, a second fixed block 7.8, a third fixed block 7.9 and a push plate 7.10. The first fixed block 7.7, the second fixed block 7.8 and the third fixed block 7.9 are arranged on the bottom plate 7.6. The first screw rod 7.1 passes through the first fixed block 7.7 and is fixedly connected with the push plate 7.10. Both sides of the push plate 7.10 are slidably arranged on the second fixed block 7.8 and the third fixed block 7.9 respectively. Under the action of the first screw rod 7.1, the upper end of the push plate 7.10 presses the third edge plate 6 to prevent it from moving on the X and Y axes.

[0047] Both ends of the cover plate 7.5 are fixedly connected to the bottom plate 7.6. The second screw rod 7.2 is arranged on the cover plate 7.5. The second screw rod 7.2 corresponds to the blades one by one. Under the action of the second screw rod 7.2, the cover plate 7.5 presses the blades to prevent them from moving in the Z-axis direction.

[0048] The bottom of the bottom plate 7.6 is provided with anti-skid feet (not shown) to ensure stability during the welding process.

[0049] The present invention separates a multi-jointed blade into a plurality of blades and edge plate structures for welding, and develops a product with qualified size and high surface quality at low cost and high efficiency.

[0050] In the above embodiments, the present invention is only exemplarily described, but those skilled in the art may make various modifications to the present invention without departing from the spirit and scope of the present invention after reading this patent application.

Claims

1. A wax mold forming method for multiple turbine guide vanes, characterized in that: The following steps are involved: S1. Split the multi-unit turbine guide vanes into two sets of structures, one set is a blade group, and the other set is a lip plate group; S2. The two sets of structures are pressed using corresponding molds respectively, mold A presses the blade group, and mold B presses the edge plate group; S3, use welding tooling for welding; S3-1, placing the leaves pressed by mold A on the bottom plate one by one; S3-2, the edge plate pressed by the mold B is placed on the upper part of the bottom plate, the outer positioning block of the welding fixture is against the edge plate located at the upper part of the workpiece; the inner positioning device of the welding fixture is against the edge plate located at the lower part of the workpiece; S3-3, tighten the second screw on the cover plate, and the cover plate presses the blades; S3-4. Connect each weld seam using an electric soldering iron.

2. A wax mold forming method for multiple turbine guide vanes according to claim 1, characterized in that: The welding fixture includes a second screw, an outer positioning block, an inner positioning device, a cover plate and a bottom plate; The outer positioning block is fixedly arranged on the upper part of the bottom plate, and the outer positioning block presses the edge plate on the upper part of the workpiece; The inner positioning device comprises a first screw, a first fixed block, a second fixed block, a third fixed block and a push plate. The first fixed block, the second fixed block and the third fixed block are arranged on the bottom plate. The first screw passes through the first fixed block and is fixedly connected with the push plate. Both sides of the push plate are slidably arranged on the second fixed block and the third fixed block respectively. Under the action of the first screw, the upper end of the push plate presses the edge plate at the lower part of the workpiece. The two ends of the cover plate are fixedly connected to the bottom plate, the second screw rod is arranged on the cover plate, the second screw rod corresponds to the blades one by one, and the cover plate presses the blades.

3. The wax mold forming method of multiple turbine guide vanes according to claim 1, characterized in that: After welding, it is inspected by 3D scanner.

4. A wax mold forming method for multiple turbine guide vanes according to claim 2, characterized in that: There are three external positioning blocks.

5. The wax mold forming method of multiple turbine guide vanes according to claim 2, characterized in that: The bottom of the base plate is provided with anti-skid feet.

Images