JPS6212508Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to an electrode for electrolytic machining of a turbine wheel.

Generally, as shown in FIGS. 1 to 3, a turbine wheel is made up of a disk-shaped base 1 and a large number of twisted and tapered blades 2 protruding from the outer periphery at a predetermined pitch.

Incidentally, various methods have been conventionally considered for processing the blade 2, and one known method is to carve it out by electrolytic machining. As shown in FIG. 4, the method using electrolytic processing includes a base 3, a pair of processed parts 4 connected to the base 3,
5 and an electrolytic solution discharge port 7 formed between the pair of processed parts 4 and 5 of the base 3. By performing electrolytic processing while flowing the electrolyte from the discharge port 7, the electrolyte is applied to the tip surfaces 4a, 5a and outer surfaces 4b, 5b of the pair of processed parts 4, 5 as shown by arrows in FIG. The parts that flow along them and face them will be electrolytically processed. However, according to such an electrode, the pair of processed parts 4,
Since both ends of the blade 5 are open, most of the electrolyte flows out from these parts, making it impossible to obtain the desired flow between the processed parts 4 and 5 and the blade wheel material 8. This prevents good electrolytic processing. I can't do it.

Therefore, recently, the open ends of the pair of processed parts 4 and 5 are closed with side plates 9, 9, and the electrolyte is transferred to the processed parts 4 and 5.
It is considered to ensure that the liquid flows along the end surfaces 4a, 5a and the outer surfaces 4b, 5b of 5. According to such an electrode, the electrolytic solution certainly flows easily along the end surfaces 4a, 5a and the outer surfaces 4b, 5b of the processed parts 4, 5. However, since the electrodes are machined into curved blades, the processed parts 4 and 5 are curved according to the blades. The flow path for the electrolytic solution is longer at both end portions close to 9 than at other portions.
That is, the flow paths of the electrolytic solution flowing along the inner surfaces of the side plates 9, 9 at both end portions of the end surfaces 4a, 5a of the processed portions 4, 5 are longer than those in other portions. Therefore, the electrolyte flows more slowly in this part than in other parts, resulting in an uneven flow rate, which makes it difficult to process this part, resulting in inconsistent electrolytic machining. There were major practical problems, such as the inability to proceed with the process.
In particular, this tendency becomes more pronounced as the curvature of the wing to be carved increases.

This idea was developed based on the above-mentioned circumstances, and its purpose is to prevent the flow rate of the electrolyte from decreasing at both ends of the end face of the processed part when the open parts at both ends of the processed part are closed with side plates. An object of the present invention is to provide an electrode for electrolytic machining of a turbine blade wheel, which enables electrolytic machining to be performed with high accuracy and high efficiency.

An embodiment of this invention will be described below with reference to FIGS. 7 and 8. In the figure, 11 is an electrode body.
This electrode main body 11 has a pair of processed parts 13 on a base part 12 formed to have approximately the same dimensions as the thickness of the impeller material.
14 are provided in parallel, and an electrolyte discharge port 15 is bored in the base 12, located between the pair of processed parts 13 and 14. The processed parts 13 and 14 are curved in the same direction with a curvature corresponding to the blade to be machined. Furthermore, side plates 16 and 6 made of an insulating material are attached and fixed to both side surfaces of the electrode body 11 by screws 17 to close open portions between both ends of the pair of processed parts 13 and 14. Above side plate 1
Processed parts 13 and 14 are formed on the opposing inner surfaces of 6 and 16.
A total of four recesses 18 are formed at locations corresponding to both end surfaces 13a and 14a of the recesses 18. That is, the recessed portions 18... are curved processed portions 13, 1
Among the corners formed by the outer surfaces 13b, 14b and inner surfaces 13c, 14c of 4 with the side plates 16, 16, the corners on the acute angle side are carved so as to be partially open. To explain further, the recess 18 is opened so that one of the processed parts 13 is partially opened on the outer surface 13b side, and the other processed part 14 is partially opened on the inner surface 14c side.
...is formed.

In the electrode configured in this way, electrolytic processing is performed while supplying electrolyte from the discharge port 15 formed in the base 12 with both side surfaces of the impeller material in the thickness direction sandwiched between the pair of side plates 16, 16. Do this. Then, the electrolytic solution flows between the inner surfaces 13c and 14c of the pair of processed parts 13 and 14, passes through the end surfaces 13a and 14a, and flows along the outer surfaces 13b and 14b, so that the electrolyte flows between the inner surfaces 13c and 14c of the pair of processed parts 13 and 14, and along the outer surfaces 13b and 14b.
The portion facing 14b will be electrolytically processed. That is, since the open portions at both ends of the pair of processed portions 13 and 14 are closed by the side plates 16 and 16, the electrolyte does not flow out from these portions and flows along the end surfaces 13a and 14a and the outer surfaces 13b and 14b. Further, when the electrolyte flows through the end surfaces 13a and 14a of the processed parts 13 and 14, this end surface 13
Since the flow path is longer and the resistance is greater at both end portions of a and 14a than at other portions, there is a risk that the flow rate of the electrolyte solution in these portions may decrease. However, recesses 18 are formed on the inner surfaces of the side plates 16, 16 corresponding to both end surfaces 13a, 14a of the processed parts 13, 14. Therefore, the cross-sectional area of the flow path at both end portions of the end surfaces 13a, 14a of the processed portions 13, 14 is expanded by these recesses 18, and the flow path resistance is reduced, so that the same amount of water is applied to both end portions and other portions. The electrolytic solution flows and uniform electrolytic processing is performed. Moreover, the recessed portions 18... are the processed portions 13, 1
Among the corners where the inner and outer surfaces of 4 form with the side plates 16, 16,
Since it is formed so that a part is open on the acute angle side where the flow path resistance is large, this also allows the processed portions 13, 1
The flow path resistance of the electrolytic solution at both end portions of the end face of No. 4 is greatly reduced, and the electrolytic solution easily flows into these portions.

In addition, in the above embodiment, an electrode in which a pair of processed portions were formed was used, but the engaging electrode in this invention is not limited to the number of processed portions, and may have two or more processed portions. It is fine as long as it is something.

In addition, although the pair of processed parts of the electrode are arranged at a spacing that sandwiches one blade, the pair of processed parts described above may be spaced so that two or more blades are sandwiched between them. Since the angle formed by the outer surface of the blade with respect to the feeding direction of the electrode becomes larger, it is possible to process a blade with a larger twist than in the above embodiment.

As described above, this invention uses a side plate to close the open ends at both ends of the plurality of processed parts arranged in parallel on the electrode body, and the side plate has a portion corresponding to both ends of the tip of the processed part. Since the concave portion is formed, the flow path resistance of the electrolyte at both ends of the tip of the processed portion is reduced by the concave portion, and the electrolyte flows uniformly over the entire tip. Therefore, since the electrolytic processing in the processing section becomes uniform, processing accuracy and processing efficiency can be improved.

[Brief explanation of the drawing]

Figures 1 to 3 show the turbine blade wheel; Figure 1 is a plan view, Figure 2 is a sectional view, Figure 3 is a front view of the blade seen from the direction of the arrow in Figure 1, and Figure 4 is a front view of the blade as seen from the direction of the arrow in Figure 1. The figure is an explanatory diagram showing the machining state using conventional electrodes.
The figure is a perspective view showing an improved type of the conventional electrode, FIG. 6 is an explanatory diagram showing the flow state of the electrolyte at the tip surface of the electrode, and FIGS. 7 and 8 show an embodiment of this invention. Figure 7 is a plan view, Figure 8 is Figure 7-
It is a sectional view along a line. 11... Electrode body, 12... Base, 13, 14
... Processing section, 15 ... Discharge port, 16 ... Side plate, 1
8... Concavity.

Claims (1)

[Scope of utility model registration request] An electrode body having a base and a plurality of curved processed parts that are arranged in parallel at a distance from each other on the base and whose widthwise ends are thicker than other parts, and an electrolytic solution between the opposing processed parts formed on the base. a pair of side plates attached to both end faces in the width direction of the processed part so as to close the gap between these end faces; and a pair of side plates formed at positions corresponding to the tips of the processed part of the side plates. An electrode for electrolytic machining of a turbine impeller, characterized by comprising a concave portion.