JPS6133965B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a turbine wheel in a supercharger for an engine.

Conventionally, this type of method involves forming a turbine wheel a by casting a titanium alloy or other heat-resistant alloy as shown in the first figure, and then forming the turbine wheel a into an operating shaft b.
A center hole c is attached to the outer end of the wheel a to be attached by friction welding or other means to the end of the wheel a, and then machined.
However, in this case, the wheel a not only does not have a hollow part inside as shown in the figure, but also has a thick wall extending longitudinally at the outer end in preparation for machining the center hole c. The part d is integrated, and such a part has a relatively large weight as a whole, and it overhangs the intermediate bearing e that supports the operating shaft b, thus hindering its operation. According to this method, a relatively large load is likely to be applied to the bearing e, which is disadvantageous.

The object of the present invention is to provide a method for obtaining a wheel free of such disadvantages, in which the turbine wheel is formed by casting titanium alloy or other heat-resistant alloy and then attached to the end of the operating shaft. In the case of a type in which the wheel is joined by friction welding or other means, and then a center hole is machined in the outer end of the wheel in preparation for grinding or other machining, the outer end of the wheel is thinned in advance in preparation for machining the center hole. It is formed into a hollow body having a thick part and a hollow part extending in the length direction inside the thick part, and after the machining, the thick part is removed and the hollow part is opened.

An example of an embodiment of the present invention will be explained with reference to attached drawings.

Figures 2 and 3 show one example.
indicates a turbine wheel, and the wheel 1 is made by casting titanium alloy or other heat-resistant alloy, and after bonding it to the end of the operating shaft 2 by friction welding, a center hole 3 is formed at the outer end. The wheel 1 is prepared for grinding and other machining operations, and this point is not particularly different from conventional wheels. However, according to the present invention, the center hole 3 of the wheel 1 is machined in advance as shown in the third figure. In preparation for this, a hollow body is formed having a thick wall portion 1a at the outer end and a hollow portion 1b extending in the length direction inside the thick wall portion 1a, and this is connected to the actuating shaft 2, and the center hole 3 is formed at the outer end of the hollow body. After processing and performing machining on this, the thick portion 1a is then removed by cutting or other means to open the hollow portion 1a to the outside. This state is as shown in the second figure, in which reference numeral 4 indicates a compressor wheel at the other end of the operating shaft 2, and reference numeral 5 indicates a bearing at an intermediate portion thereof. The entire supercharger that uses this is as shown in FIG. The inside of the passage 7 and the wheel 4 are inserted into the inside of the intake passage 8, respectively.

In this way, according to the present invention, the turbine wheel is made into a hollow body having a thick walled portion at the outer end in advance, and after machining is performed by machining the center hole of the thick walled portion, the thick walled portion is removed. The internal hollow part is opened, so there is no problem with machining, and the wheel is extremely lightweight as a product, which does not put a large load on the bearing, allowing smooth and reliable operation. It has the effect of making it.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram of a conventional example, Figs. 2 and 3 are explanatory diagrams of an example of the method of the present invention, and Fig. 4 is a cutaway side view of an example of a supercharger using the product. be. 1... Turbine wheel, 2... Operating shaft, 3...
...Center hole, 1a... Thick part, 1b... Hollow part.

Claims (1)

[Claims] 1. After forming a turbine wheel by casting a titanium alloy or other heat-resistant alloy, it is attached to the end of the operating shaft by friction welding or other means, and then a center hole is machined in the outer end of the wheel, and the wheel is ground, etc. In a type prepared for machining, the wheel is formed in advance into a hollow body having a thick part at the outer end and a hollow part extending in the length direction inside the thick part in preparation for the machining of the center hole. A method of manufacturing a turbine wheel, which comprises removing the thick part and opening the hollow part after machining.