JPS631139B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is a method for manufacturing a cylindrical container such as a main body container of a rotary electric compressor, which is formed by drawing a steel plate and has a fitting part that fits with parts housed inside. Regarding.

Some cylindrical containers of this type have an electric element 2 and a compression element 3 directly fixed to a main body container 1 by shrink fitting or the like, as shown in the closed type rotary electric compressor shown in FIG.

Conventionally, the main body container 1 is formed into a cylindrical container by drawing a relatively thick plate, and the fitting portion of the cylindrical container between the electric element 2 and the compression element 3 is machined to achieve dimensional accuracy. It was formed using a construction method that achieved dimensional accuracy by expanding or correcting it with an expander.

However, mechanical cutting is disadvantageous in that it causes an increase in costs, and there are many unstable factors that cause variations in dimensional accuracy. In addition, the method using an expander requires an annealing process in advance for straightening.
However, this process has the disadvantage that the processing speed up to the reduction of the material structure is slow, and the amount of energy consumed in this process is enormous.
There is a sense of strangeness as there is an annealing process in the middle of the process.
It was also disadvantageous in terms of process control.

The method for manufacturing a cylindrical container according to the present invention has been made in view of the above points, and when drawing a steel plate, the part corresponding to the fitting part where parts to be accommodated at the same time fit is made into a polygonal cylinder. By pressing this polygonal cylindrical portion by ironing, a predetermined dimensional accuracy can be obtained without the need for conventional processes.

Embodiments of the method of the present invention will be described below with reference to FIGS. 1 to 7. In the figure, 1 is a cylindrical main body container of a hermetic rotary compressor, 2 is an electric element that is shrink-fitted and fixed to the main body container 1, and 3 is a main body container 1.
a compression element that is shrink-fitted and fixed to the electric element 2;
It is a component housed in the main body container 1 together with the main body container 1.

Main body container 1 of a hermetic rotary compressor having such a configuration
For example, if the height of the product is such that it cannot be formed by one drawing process, in order to sequentially process the steel plate 11 into the product shape as shown in FIG.
Continue redrawing →13→14.

That is, as shown in FIG.
Drawing tools 15, 16 each having a plurality of flat surfaces having an arc height H and a chord length S that correlate to the plate thickness.
Then, the drawing process is performed in a drawing process opposite to the first re-drawing process, and the front and back sides of the drawing work 17 in the previous stage, that is, the first re-drawing process, are reversed as shown in the drawing work 17', and the inner and outer surfaces of the plate material are While balancing the internal stress, a plurality of flat surfaces having an arc height H and a chord length S are formed on the drawing workpiece 17' to form a polygonal cylindrical portion 18 at the same time. Note that this string portion naturally has a gap larger than the predetermined clearance with the die.

Therefore, during the reverse drawing process, the tension in the axial direction is weakened and the flow of the material is suppressed, and the shrinkage deformation in the circumferential direction is concentrated in the chord part, causing the plate thickness to decrease along the set circumference. The stress and strain including this will maintain balance.

Then, the drawing work 17' formed in the reverse drawing process is transferred to a second re-drawing process, and the polygonal cylindrical part is pressed and a substantially cylindrical fitting part 19 is formed. .

During this second re-drawing process, plastic elongation is applied by tension, so the circumferential tensile stress is attenuated and the shape is frozen and stabilized after unloading.

In this way, in the previous stage of re-drawing, the stress distribution in the plate thickness plane due to reverse drawing is equalized, and the material flow in the axial direction is uniformly bundled and divided at the fitting part 19 with the above-mentioned compression element or electric element. Balance of stress distribution can be obtained. In addition, as shown in Figure 7 below, the sufficient tensile action of the re-drawing process and iron-drawing eliminates residual stress and drastically reduces deformation after drawing, improving the accuracy of the fitting part of the cylindrical container. can be ensured. In addition, the reciprocating motion of the tool in the ironing and drawing process smoothes the surface of the cylindrical container.
These banin specifications harden the surface layer, increasing the fatigue resistance of the material. Therefore, the mechanical properties of the surface layer and the repetition of elastic strain received from the machining of most of the material from the surface plane are restrained, and the effect of accurately transposing the mold precision is promoted.

As explained above, according to the method for manufacturing a cylindrical container according to the present invention, a steel plate is drawn and at the same time the fitting part with the parts to be accommodated is formed into a polygonal cylinder part, and this polygonal cylinder part is By pressing it into a substantially cylindrical shape by ironing, it is possible to process from beginning to end while ensuring the dimensional accuracy of the fitting part in a series of pre-tacts, which reduces costs and facilitates process control, which has great effects.

[Brief explanation of the drawing]

Figure 1 is a schematic vertical cross-sectional view of a sealed rotary electric compressor using a cylindrical container, Figure 2 is a side cross-sectional view showing the process development of deep drawing, and Figure 3 is reverse drawing in the first re-drawing process. Figure 4A is a cross-sectional view of the workpiece side showing reversal.
FIG. 4B is an enlarged view of the peripheral edge of the drawing tool in the re-drawing process, FIG. 5 is a front view of the drawing tool, and FIG. 6 is a first embodiment of the present invention. FIG. 7 is a sectional view of the workpiece after the second redrawing process. 1... Main body container, 2... Electric element, 3... Compression element, 15, 16... Drawing tool, 17, 17'...
...Drawing work, 18...Polygonal cylinder part, 19...
…Fitting portion.

Claims (1)

[Claims] 1. When producing a cylindrical container that is formed by drawing a steel plate and has a fitting part that fits with a part housed inside, the steel plate is drawn and at the same time the fitting part is formed into a polygonal cylindrical part. A method for manufacturing a cylindrical container, characterized in that the container is pressed by ironing into a substantially cylindrical shape.