JPS60116805A - Manufacture of partition plate by casting - Google Patents

Abstract

PURPOSE:To manufacture the partition plate having the high accuracy by simple and low cost process by a method wherein a nozzle block is cast by joining plural nozzle plates with both an inner and outer side shrouds, then the cast block is assembled to be annular shape, finally, the both shrouds are cast to form the inner and outer rings. CONSTITUTION:At the manufacturing of a turbine partition plate, initially, a nozzle block 9 is manufactured, that is, plural nozzle plates 1 are disposed in raw in annular shape and with required setting angle. An inner and outer shrouds 8, 7 having plate shape are arranged respectively at the inner and outer peripheries of the nozzle block. A casting part 4 are protruded at the opposite location to the nozzle plate 1 on each inner and outer side of the both shrouds 8, 7. Subsequently, the required number of the block 9 are disposed in array for assembling in annular shape manner. Finally, a molten material is cast at the both shrouds 8, 7 parts including the casting parts 4, thus, the inner ring 6 and the outer ring 5 are formed. Thereby, the turbine partition plate having high accuracy can be manufactured by simple and low cost process.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a turbine partition plate, particularly a geothermal turbine partition plate, by using a fishing method.

The conventional method for manufacturing turbine partition plates by casting is the first method.
As shown in Figures a and lb, a plurality of nozzle plates 1 are manufactured one by one by each pressurizing method such as machining, forging, or casting, and the required number of nozzle plates 1 are arranged in an annular shape to maintain a necessary angle of entry. After arranging them in parallel, molten iron or steel is poured into the outer and inner circumferential sides to form the outer ring 2 and inner ring 3, respectively, and then machining and hand finishing are performed at the necessary locations to form the required partition plate. However, since finishing allowances by casting are kept in advance on the steam passage wall parts (a) and (b) of the outer ring and inner ring, it is difficult to finish the parts. The unavoidable disadvantage is that a considerable amount of finishing time and construction costs are required.

This invention was made in view of the current situation, and involves pre-precision casting of a required number of nozzle blocks, each consisting of a plurality of nozzle plates connected by inner and outer shrouds, and then molding the blocks into an annular shape. It is an object of the present invention to provide a method for manufacturing a partition plate by casting, which eliminates the drawbacks of the conventional method by casting the inner and outer shrouds to form inner and outer rings, respectively, after assembly.

Next, an embodiment of the present invention will be described with reference to the drawings.
In Figures 2.3a and 3b, first, the nozzle block 9 shown in Figure 2 is prepared in advance.
Multiple sheets (Figure 2 shows the case of five sheets)
The nozzle plates 1 are arranged in an annular shape with a required mounting angle, and a plate-shaped inner shroud 8 and an outer shroud 7 are disposed on the inner and outer peripheries of the nozzle plates 1, respectively, and are connected to each other. A casting part 4 is provided protrudingly at a position corresponding to the nozzle plate, respectively, and is precision cast using a method such as lost wax. Next, after assembling the required number of blocks in parallel to form an annular shape, the casting part is enclosed in the inner and outer shrouds 8.7, and molten iron or steel is poured into the inner ring 6 and the outer shroud 8.7. After forming the outer rings 5, the parts of both the wheels other than the nozzle plate are completed (Figs. 38 and 3b).

Therefore, according to the present invention, since the nozzle plate 1 is used as the nozzle block 9 and manufactured by precision casting, the manufacturing cost can be significantly reduced, and no machining costs are required. Because the casting work is carried out by assembling them side by side, construction up to the casting work is extremely easy.In addition, since the walls of the steam passage are precision cast by the shroud of the blocks, hand finishing is easy. This eliminates the need for additional machining, resulting in a significant reduction in cost.Furthermore, the nozzle plate 1 can be manufactured with high precision when each nozzle block 9 is manufactured, which eliminates the need for assembling and casting the nozzle plate one by one as in the conventional technology. In comparison, the accuracy is extremely high, and the nozzle performance is greatly improved, so the industrial value of this invention is extremely high.

[Brief explanation of drawings]

Fig. 1a is a vertical cross-sectional side view showing the main parts of a partition plate produced by a conventional method of manufacturing partition plates by casting, Fig. 1b is a cross-sectional view taken along line A-A in the previous figure, and Fig. 2 is a cross-sectional view of the embodiment of the present invention. FIG. 3a is a perspective view of the nozzle block according to the example, FIG. 3a is a longitudinal sectional side view showing the main part of the partition plate according to the embodiment of the present invention, and FIG. 3b is a sectional view taken along line BB in the previous figure. 1. Nozzle plate, 2. Outer ring, 3. Inner ring, 4. Casting part, 5. Outer ring, 6. Inner ring, 7. Outer runout, 8. Inner shroud, 9. Nozzle block. Figure 1a Figure 2 Figure 3 σ Figure 3b

Claims (1)

[Claims] A required number of nozzle blocks, each consisting of a plurality of nozzle plates connected by inner and outer shrouds, are precision cast in advance, and after the blocks are assembled into an annular shape, the inner and outer shrouds are cast and the inner and outer shrouds are connected, respectively. A method of manufacturing partition plates by casting, the characteristic of which is to form an outer ring.