6 Cangzhou 350 Jia Jia turbine generator stator punching the stamping Tang Qunhua Shanghai Electric Factory Co., Ltd. Technical Development Center. This paper describes the stamping process of stator punchings for 350MW turbo-generators, the structural features of the body blanking film, and the manufacturing quality control plan.
1 Introduction Quzhou 35, turbogenerator is a product jointly produced by American Westinghouse and Shanghai Electric Turbine Generator Co., Ltd., and our company is responsible for the manufacture of stator and base parts.
The difference is that the 300MW 600MW turbine generator, the stator adopts an axial ventilation structure, the structure of the corresponding stator sector is also a great change, each stator fan-shaped piece is distributed with a lot of axial ventilation holes, the size of punching tablets This is particularly large, which brings a lot of difficulties to the structural design and manufacturing of the sector-shaped blanking die. In order to reduce the difference between materials, Westinghouse requires that the blanking center of the stator segment must be on the centerline of the roll blank. However, the existing equipment of our company cannot perform the pipeline operation for stamping the stator segment. Can use manual operation. Taking into account the safety, higher requirements are placed on the die structure design and the punching process.
Compared with the previous 300MW 600MW, the production process of 350 turbo-generator stator segments is required to be evaluated according to the Westinghouse process specification from the raw material storage identification to the process document preparation production process control packaging shipment. In order to ensure new process measures for the 350MW stator segment.
2 The major process difficulties in the Westinghouse process specification.
2.1 When punching, the direction of the teeth of the punching sheet must be perpendicular to the material's dairy direction. The punching center of the punching sheet should be on the centerline of the material and the bushing should be used.
2.2 The punching piece is only allowed to have one-sided burrs, and it is not allowed to have defects such as bending deformation. The die unloading device is not allowed to damage the punching pieces.
2.3 The scratches of the punching sheet shall not exceed the edge of the punching sheet. 3 The burr-free burr allows a small amount of random burrs after the hair removal. The burr height is less than 0.013. The burr position of each punching sheet cannot be in the same position.
2.4 The lacquer sheet should be rust-proof, but no rust inhibitor should be used.
3 Determination of process plan The material of the 350MW turbo-generator stator segment is made in China, evaluated as 3290, 0.5, 1 thick cold-rolled silicon steel sheet, and the full circle is composed of seven semi-stator segments, each with stator segments. With 36 axial vents and 2 screw holes, and with different dimensions and positions on the stepped punching sheet, the following process flow 2 and solution were determined according to the Westinghouse process specification requirements.
3.1 Shearing Because of the advanced stamping equipment of Westinghouse, the workbench is inclined, and the trapezoidal billet will move smoothly to the die edge, so the size of the trapezoidal trim can be as long as the requirements on the product sample. Our company's stamping equipment is relatively low. When the punching stamping, the trapezoidal cutting material can only be manually sent into the die mouth, and the blank has a wide mouth with 1000 claws. So it is necessary to do the punching center on the center line of the roll blank. The teeth are perpendicular to the billet rolling direction. The process flow must be taken into consideration. The operator can completely operate the blanks during the blanking. Determined as the size of the crop and the width of the plan billet 3.1.1 shearing 10001677 parallelogram shape. If å› 3! And sequentially stacked 3.1.2 points cut into 8 trapezoidal, 315, the film will be stacked in turn staggered; 3.1.3 will be 8 trapezoidal cut in turn to the shadow of the big head. 30, and in turn stacked.
Rolling direction å›3 shape cutting é’3.2 Falling material falling All the shape of the punching hole and the screw hole, when the blanking material is trapezoidal material large side and side positioning.
3.3. Cutter-cutting In order to prevent magnetic leakage at the end, the punching pieces at both ends of the core are step-like punching and slot punching, step-like punching and cutting of the inner circle of each file.
3.4 Punching slits, due to the symmetry of the slit groove position on the centerline of the punching sheet, the secondary punch cannot be punched completely, and half punching is needed. After the punch is half finished, the positioning and punching are the other half. The 3.5 punched yoke washer is used to compensate. The difference between the same material, in the yoke of the stator sector piece needs to pad a predetermined number of yoke gasket, when the punching system with the body on the 2415.88 vent hole positioning, punching by the CNC32 automatic punching machine.
3.6 Dehairing Because the company's existing belt-stripping equipment has a width of 1000mm, and the stator segment has a chord length exceeding 1000, it cannot be depilated by conventional methods. Therefore, after testing, the punching sheet is tilted at an angle, and the yoke is fed into the hair. Machine hair removal.
3.7 Varnishing Paints are baked according to the special requirements of Westinghouse's hedge plate coatings.
4 The selection of the punching equipment mainly refers to the selection of punching equipment when the punching of the body punch is doubled, and the punching force is calculated from the perimeter thickness and shearing strength of the root punching sheet.
The calculation formula is ±1.3 children 1L blanking perimeter, 1 blanking material thickness, 0 blanking material shear strength 宕, 2 according to the calculation data P should be considered when the pressing pressure is sufficient, but also need to consider the work The size of the countertops is sufficient. Comprehensive analysis of our company's existing production equipment, the selection of the new 3150KN gantry press is the most suitable. The working surface of this press is 16000,2000. It is estimated that there are enough molds to be installed, and this punch has a manipulator. When punching, it is considered to take the manipulator to remove the workpiece, which can facilitate the stamping operation.
5. The selection of the structural design solution mainly refers to the die structure of the body stator segmented double blanking die. Due to the large size of the punching die, the convex and concave die adopts the conventional large-segmented block structure, and the dimensional accuracy of the product is required to be high. There are many punching pieces, so the structure of the die adopts a ball-type guide pillar guide structure in a flip-up manner, but its structure is different from the conventional one, in which the guide pillar adopts a detachable structure, that is, the guide pillar is used when installing the mold, and the adjustment is required. After the school is qualified, the guide pillars near the left side of the operator are removed, which is convenient and safe to operate. The other key is that the unloading device and the waste discharging method of the mold are completely different. Because the Westinghouse Company requires that the die unloading device can not damage the punch. Sheet, so the unloading device of the mold adopts a small guide post structure, which improves the guiding performance of the top bar in the unloading device, and makes the punching sheet stuck in the die after punching as flat as possible when the punching sheet is pushed down from the top bar. Under the premise of the overall structure, there is still a question of waste. Because the size of the waste hole in the punching equipment is only 4450, and the distribution size of the ventilation holes on the punching sheet is much larger than this diameter, in order to solve this problem, in the premise that the stamping equipment cannot be improved, some methods are to be welded on the lower mold base of the mold. The reinforcing ribs allow the material to fall on the work surface between the reinforcing ribs, and then manually discharge the waste material. This fills the gaps in the equipment. Under the premise of using the existing equipment, it can not only ensure the normal operation of the equipment, but also ensure product quality.
6 Formulation of Manufacturing Quality Control Plan Due to the special nature of the product, in addition to the preparation of process cards and corresponding process codes, a set of manufacturing quality control plans must be prepared in accordance with Westinghouse's process specification requirements. This plan must not only meet the production habits of our company, but also be approved by Westinghouse. As a guiding document in production, it describes in detail all the contents of the manufacturing process and the process. The main points are as follows 6.1 Process technology preparation requirements All gauges and instruments used in the inspection of products are in good condition. The operator must hold the relevant employment certificate and the quality assurance book etc.
6.2 Starting from the beginning of rolling the billets, the production shop is required to record on the logistics card the number of the project number, the number of large volumes, the number of small volumes, and the weight of materials. Each small volume of trapezoidal scissors is stacked on a shelf. Make every slice has its source, every 6 cut! 1 check, and record the size of the trapezoidal scissors is correct, if there is any mistake should be promptly corrected. Every process from the end of trimming to the end of painting shall be done with care and care to avoid bending and deformation of the stampings.
6.3 After punching, each type of stamping shall be firstly inspected. The first inspection shall be used as a sample. During the production inspection, the staff shall take the sample as the standard for inspection and inspection. Any unqualified position shall be immediately shut down to find the cause until the qualified party. Can continue to produce.
6.4 When the punching process is used for punching, the mold structure and equipment can completely pass through the garbage to prevent clogging of the waste and shorten the service life of the mold.
6.5 After step-like punching, after every 50,1 inspections, the size of the screw holes is smaller than that of the two punching sheets.
20mm positioning pin positioning, if more than 0.
76! Above must be removed or reworked.
6.6 When punching all punching sheets, attention must be paid to the direction of the burrs to maintain the directionality of the burrs. When the shavings are tilted at the time of hair removal and when the test is performed, after the hair removal gap is adjusted according to the thickness of the punching sheet, the edge scratches cannot exceed 3, and the hair removal The punching surface must not be damaged during the process, otherwise it must be removed. No burrs after hair removal.
6.7 Punch film painting must be carried out in order of each punching film, can not be confused. After finishing the painting to prevent rusting of the punching sheets, they must be stacked one on top of the other on a shelf covered with special paper. After cooling, the punching sheets should be timely caught in a plastic bag, and the rust-proof powder should be placed in each plastic bag. Each of the punching sheets must be promptly remedied if it is damaged during lifting.
7 Conclusion The stamping of the 350MW turbo-generator stator punching plate, under the strong support of the company's leaders and the vigorous cooperation of the production workshop, overcome various difficulties and solve the quality requirements of various technically difficult products, and also completed the task ahead of time. Westinghouse expert highly praised. To this end, Westinghouse intends to continue the stamping of the stator segments of the 900MW turbo-generator with our company, which has enabled us to open up a broader market.
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