JPS6263198A - Production of turbine rotor blade - Google Patents

Abstract

PURPOSE:To reduce the number of machining processes by working a raw material in a shape having plural spiral lugs to become vanes on the outer periphery of a cylinder by extrusion molding and cutting out lugs on longitudinal ends of a sectionally split portion. CONSTITUTION:A raw material 23 is worked into a product 26 having plural spiral lugs 25 on the outer periphery of a cylinder 24 by hot extrusion molding. The product 26 is sectionally split on a plane perpendicular to the axis in a required size width, and lugs 25 on both longitudinal ends are cut out by machining to produce a rotor blade. Accordingly, most of the rotor blade including the vane section is molded by plastic working, and the number of machining processes can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a method of manufacturing a turbine rotor blade used in a turbo-molecular pump or the like.

<Prior Art> FIG. 4 shows a longitudinal cross-sectional view of an example of a turbo-molecular pump. As shown in FIG. 4, the turbo molecular pump 11 has an intake port 13 in the upper part of its casing 12 and an exhaust port 14 in the lower part, and by rotating a plurality of moving blades 16 attached to a rotor 15 at high speed, A rotor blade 16 is provided on the inner peripheral surface of the casing 12.
It performs the exhaust action in cooperation with stator vanes 17 installed alternately. A rotor shaft 18 that supports the rotor 15 has an upper bearing 2 in a stator cylinder 19 that is installed upright in the casing 12.
A motor 22 as a drive device is inserted between the rotor shaft 18 and the stator cylinder 19.

As shown in FIG. 5 (Jl) showing a front view thereof and FIG. 5(b) showing a half-cut plan view thereof, the moving blade 16 has a plurality of blades 16b radially arranged on the outer peripheral surface of a cylindrical boss 16a. It has a protruding shape, and each blade 16 is attached to a boss 16a in a twisted manner at a certain angle with respect to the axis.

Conventionally, the rotor blade 16 has been manufactured by cutting out a ring-shaped material by machining.

<Problems to be Solved by the Invention> However, when cutting the rotor blade 16 from a ring-shaped material by machining, there are many parts that become chips, which not only results in poor material yield but also requires a long machining time. However, there was a problem in that the manufacturing cost was high.

The present invention solves these problems in the production of conventional turbine rotor blades, and provides a manufacturing method that uses plastic working to improve material yield and reduce man-hours, thereby making it possible to manufacture turbine rotor blades at low cost. It is intended to.

Means for Solving the Problems> To achieve this object, the method for manufacturing a turbine rotor blade according to the present invention has a structure in which a plurality of spiral protrusions that become blades are formed on the outer periphery of a cylinder by extrusion molding a material. The turbine rotor blade is manufactured by processing the rotor blade into a shape having a shape, cutting it into rounds with a required size width, and cutting off the protrusion at the axial end of the sliced portion.

Function: Since the majority of the blades, including the blades, are formed by plastic working, the number of machining steps is greatly reduced. On the other hand, by cutting off the protrusions at the axial ends of the sections cut into rings to the required dimensions, The axial length of the vane is determined.

Embodiment One embodiment of the present invention will now be described with reference to the drawings. FIG. 1 is a cross-sectional view of the extrusion molding machine according to this embodiment, FIG. 2 is a right side view of the male mold thereof, and FIG. 3 is a perspective view of a sliced portion of the extruded material.

In this embodiment, a soft alloy material such as an aluminum alloy is used, and as shown in FIG. The shaped product 26 is subjected to hot extrusion molding. In FIG. 1, 27 is a male mold, 28 is a female mold, 29 is a container holding them, and 30
is a bushing ram that pushes out the material 23. As shown in FIG. 2, the male die 27 is provided with a plurality of circular extrusion holes 27a through which the material 23 is extruded, while the inner periphery of the female die 28 is provided with a cylindrical hole for the extruded product 26. In order to form a spiral protrusion 25 on the guide groove 24, a plurality of guide grooves 28a are provided which are twisted with respect to the axial direction thereof.

Next, the product 26 extruded in this way is
Cut into rounds on a plane perpendicular to the axis to the required width as shown in the figure.
Thereafter, the protrusions 25 at both axial ends of the sliced portion are removed by machining to produce a rotor blade 16 as shown in FIG. 5. Here, the cylinder 24 becomes the post 16a, and the remaining protrusion 25 becomes the blade 16b.

Although this embodiment shows an example in which a porthole die method is used as the extrusion method, it is also possible to use an extrusion method for a cylindrical material using a mandrel or the like. In this case, a die for processing the outer peripheral surface of the cylinder is provided with a guide groove for forming the spiral protrusion.

<Effects of the Invention> As specifically explained above with reference to one embodiment, according to the present invention, most of the rotor blade including the blade portion is formed by plastic working, which significantly reduces the number of machining steps. It is possible to improve the material yield and reduce the manufacturing cost.

[Brief explanation of drawings]

FIG. 1 is a sectional view of an extrusion molding machine according to an embodiment of the present invention, FIG. 2 is a right side view of the male mold thereof, and FIG. 3 is a cross-sectional view of the extruded material cut into rings 9. 4 is a longitudinal cross-sectional view of an example of a turbo-molecular pump, FIG. 5(a) is a front view of its rotor blade, and FIG. 5(b) is a half-cut plan view thereof. In the drawings, 16 is a moving blade, 16m is a boss, 16b is a blade, 23 is a material, 24 is a cylinder, and 25 is a protrusion.

Claims (1)

[Claims] The material is processed by extrusion molding into a shape having a plurality of spiral protrusions that serve as wings on the outer circumference of a cylinder, which is then sliced into rings with a required dimension width, and the protrusions on the axial ends of the sliced parts. A method for manufacturing a turbine rotor blade, comprising manufacturing the turbine rotor blade by cutting out the blade.