JPH0350625B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a method for manufacturing a metal hollow cross-sectional section for a generator made of copper or copper alloy,
This invention relates to a method of producing a hollow section from a copper block by pressing through a mandrel or a mandrel, and shaping it to the final size by drawing.

In a known method (GB 1,099,850), a copper profile with a rectangular cross-section and at least two longitudinally extending channels is produced in a continuous casting process and then cast to final dimensions. Pultruded. Starting from this known method, there has long been a desire to make hollow cross-sections with non-continuous passages easier to handle.

In another prior invention, a pressed hollow profile is first corrected on the outside and optionally also on the inside, and one or more holes of this corrected profile are filled with the same metal as the profile. Insert a stopper consisting of
The profile section is then pultruded together with the plug to its final dimensions, with the plug and the inner wall of the hollow profile being connected to each other in a squeeze fit.

This "connected to each other in a press-fitting manner" refers to, for example, two metal parts that are joined together, and when this joined object is struck somewhere, it appears as if both metal parts were made of a single part. This refers to the state in which the parts are firmly fixed and connected to each other so as to produce a sound like this. (The same applies hereinafter in this specification).

Since it is important for the hollow cross-section sections mentioned above to have high dimensional accuracy, it is absolutely necessary to reduce the dimensions using a so-called mandrel. A mandrel is a mandrel that is held on a chain or mandrel in the area of the die. This prior method has the disadvantage that at least one half of the hollow profile has to be pulled out in the direction of the mandrel, and the mandrel rod is therefore subjected to pressure.

The invention provides a method which makes it possible to economically produce hollow cross-sections with one or more discontinuous cooling passages, i.e. hollow cross-sections with blind holes starting from both ends. This is the issue.

This problem is solved as follows. That is, according to the present invention, a plug of a limited length is arranged in a press-fit manner on one side of one or more holes of a hollow section, and two hollow sections prepared in the same manner are combined. , are connected to each other by resistance welding at the ends on the plug side, and the dimensions of the discontinuous hollow cross-section members thus configured are corrected by hollow drawing.

This problem can also be solved as follows. That is, inserting a plug made of the same metal as the cross-section into one or more holes of the corrected cross-section, and applying a layer of wax to the outer surface of the plug before inserting the plug; This can be achieved by drawing the profile together with the plug to its final dimensions and finally brazing each plug to the inner wall of the hollow profile by applying heat from the outside.

The main advantage of this method is that the stopper can be fixed in the hole, providing a hollow profile with a reliable seal. In the first method, the plug is connected to the hollow profile in a squeeze fit by pulling it out after it has been inserted. However, it is also possible to adapt the plug approximately to the diameter of the hole and push it into the hole.
When joining by resistance welding, it is important that the cross sections to be joined be the same. In a further concept of the invention, the hollow profiles are welded together with a solid copper part interposed therebetween. This solid copper part has the same cross-sectional dimensions as the hollow profile with the plug. After welding, the discontinuous hollow section produced in this way is annealed in order to recrystallize the weld seam. This annealing step is followed by hollow drawing to further correct the profile and provide the required strength. It is also important that the surfaces to be welded are parallel and in close contact. For this reason, the hollow cross-section to which the plug is connected in a press fit is cut smoothly in the region of the plug and, if necessary, further processed. The weld burrs produced by resistance welding are removed by cutting before hollow drawing, which is expediently carried out in the same step as the welding.

For brazing, it is advantageous to anneal the profile section before the product drawing process. This method is used when hardened or semi-hardened profiles are desired. Annealing to remove hardening that occurred during the previous processing step is performed during brazing. By subsequent drawing of the product, the cross-sectional profile is corrected to the desired dimensions.

Advantageously, each stopper is wrapped with a wax foil consisting of hard wax containing phosphorus. For a purpose,
In order to prevent the wax from escaping, there should be no wax oil in the end area of the stopper.

According to a further development of the invention, a plug is used which has a narrow cross section between the end regions of the plug. In this way, brazing occurs only in the central area of the plug. This embodiment can be advantageously used when the use of fluid substances cannot be avoided. The unsoldered end region of the stopper prevents flowing substances from flowing into the free channel cross section.

In contrast to the method described above, it is also possible to provide one or two holes in the hollow profile before welding. This hole opens into a narrow area of the stopper and brazing is effected by supplying hard or soft solder through the hole.

Brazing the stopper can be performed before or after the product drawing process. This can be carried out either by annealing or by supplying heat locally in the brazing area, for example by applying a flame.

The method according to the invention comprises at least two holes;
a solid portion between the ends of the cross-sectional profile;
A rectangular shape made of copper or a copper alloy with a low alloyed component,
It is particularly advantageous to use it for producing rectangular cross-section profiles. The profiles are used to cool the rotating parts of the generator.

The invention will now be explained in detail on the basis of illustrated embodiments.

The hollow profile 1 shown in FIG. 1 is made of oxygen-free copper and has two passages 2 and 3. The hollow profile 1 shown in FIG. The hollow profile 1 has a solid section 4 approximately in the middle, in the vicinity of which copper plugs 5 are provided in the channels 2 and 3.

In order to manufacture such a cooling cross-sectional section 1,
Firstly by pressing and then by cold drawing through a mandrel or mandrel, a hollow profile 1a with channels 2 and 3 is produced. A copper plug 5 is inserted into one end of the channels 2 and 3 and is connected in a press fit with the hollow profile 1 in a subsequent cold drawing. But also,
It is also possible to form copper plugs dimensionally exactly corresponding to the channels 2 and 3 and push them into them. The end of the hollow profile provided with the plug 5 is then cut smoothly and optionally ground to remove any burrs. The ends of the hollow profile shaped in this way are clamped in the welding tools 6 and 7 of a resistance welding machine and welded to a solid copper block 4 of the same cross-sectional size. During the welding process,
A current of several kiloamperes flows between the welding tools 6 and 7, and this current flows between the hollow section and the solid copper block 4.
heating the interface with the material to melting temperature. In this case, the welding tools 6 and 7 are pressed lightly. After welding is completed, welding tools 6 and 7 are removed and welding burrs are removed. The discontinuous cross-sectional profile formed in this way is then subjected to a recrystallization annealing. In this way weld line seams are removed. Hollow drawing is performed in the final processing step. In this case, the external dimensions of the hollow profile are reduced by at least 10%. This final cold working gives the hollow profile 1 the necessary strength.

In the embodiment according to FIGS. 1 and 2, a solid part 4 is interposed between the two hollow profiles 1a, 1a with channels 2 and 3; 4, directly hollow profile 1
It is also possible to weld the end faces of a and 1a to each other.

In the method shown in FIGS. 3 and 4, a hollow profile with two or more cooling channels is first drawn to product size. A plug is inserted into this passageway and is wrapped with wax foil. To prevent the wax oil from slipping when inserting the plug, the wax foil is pressed against the plug at points. The profile thus treated is drawn, with the inner wall of the channel coming into contact with the stopper.
Thereafter, the profile is softened and annealed, and the plug is soldered to the channel wall. The cross-sectional profile is then corrected, ie with a die and with a mandrel or mandrel placed in the channel.

The plug 5 is arranged in the channel 2 of the profile 1. A narrow area 16 is provided between the ends 14 and 15 of the stopper 5, which area 16 is shown in a knurled shape in FIG. Before inserting the stopper, narrow the area 16
It is stratified with wax and fluid material. The special shape of the stopper 5 prevents the wax and the fluid from coming into contact with the walls of the channel 2. In this configuration, the profile section is first drawn and then soldered. By pulling out both ends 14 of the stopper 5
and 15 seal the brazing area. At the same time, the brazing area is compressed. As mentioned above, brazing is
It is carried out together with softening annealing or with flame.

Brazing is carried out by a method not shown in the cross-section 1.
It is also possible to make one or two holes in the hole. This hole opens into a narrow area 16 into which the wax and the fluid substance are introduced through the hole.

When using such a cooling profile for cooling the rotating parts of a generator, the area in which the solid part 4 or plug 5 (FIGS. 3 and 4) is brazed improves the rotational movement. Useful for achieving mass balance.

[Brief explanation of drawings]

1 is a perspective view of a hollow cross-section profile according to the invention, FIG. 2 is a longitudinal sectional view of the profile shown in FIG. 1, and FIG. 3 shows a plug in the channel (hole) of the profile. Fig. 4 shows the state in which the stopper is brazed. Reference numbers in the drawings: 1... Sectional section, 2, 3... Passage (hole), 4... Block, 5... Plug, 6, 7...
...Welding tool, 14, 15... Both ends of the stopper, 16... Thin area of the stopper.

Claims (1)

[Claims] 1. A method for manufacturing a metal hollow cross-sectional profile for a generator made of copper or copper alloy, in which the hollow cross-sectional profile is produced by pressing from a copper block through a mandrel or a mandrel, and the final dimensions are determined by drawing. In the manufacturing method, a plug of a predetermined length is compressed and fitted on one side of one or more holes of a hollow cross-sectional shape, and two hollow cross-sectional shapes prepared in the same manner are A manufacturing method characterized in that the end faces of the end portions provided with plugs are joined to each other by resistance welding, and the dimensions of the thus processed hollow cross-sectional shape having discontinuous holes are corrected by hollow drawing. 2. A manufacturing method according to claim 1, characterized in that, after the plug has been inserted, the plug is connected to the hollow cross-section profile in a squeeze fit by pulling out. 3. A manufacturing method according to claim 1 or 2, characterized in that the hollow cross-section sections are welded together with a solid copper section interposed therebetween. 4. Manufacturing method according to one of claims 1 to 3, characterized in that the discontinuous hollow cross-section profile is annealed after welding for recrystallization of the weld seam. . 5. Manufacture according to one of claims 1 to 4, characterized in that the end of the profile provided with one or more plugs is cut smoothly before welding. Method. 6. A method for manufacturing a metal hollow cross-sectional profile for a generator made of copper or copper alloy, which involves manufacturing a hollow cross-sectional profile from a block through a core metal or mandrel by pressing, and shaping the profile to the final size by drawing. In the manufacturing method, a plug made of the same metal as that of the corrected cross-sectional shape is inserted into one or more holes of the corrected cross-sectional shape, and a wax layer is provided on the outer surface of the plug before the plug is inserted. the profile is drawn to its final dimensions together with the plug, and the plug is finally soldered to the inner wall of the hollow profile by supplying heat from the outside. 7. The manufacturing method according to claim 6, characterized in that annealing is performed simultaneously with brazing. 8. A manufacturing method according to claim 6 or 7, characterized in that each stopper is wrapped with a wax foil consisting of a hard wax containing, in particular, phosphorus. 9. Process according to one of claims 6 to 8, characterized in that a stopper is used which has a narrow cross-sectional shape between its end portions. 10 One or two on the hollow section before brazing
one hole is provided, which opens into a narrow cross-sectional area,
10. The manufacturing method according to claim 9, wherein the brazing is carried out by supplying hard or soft solder through the holes.