JPH04112733U - Small hole electrical discharge machine - Google Patents

Abstract

(57) [Summary] (with amendments) [Purpose] Regarding electric discharge machines applied to machining small holes such as cooling air holes in long torsional rotor blades such as gas turbine rotor blades.
The aim is to improve the yield of precision casting during rotor blade manufacturing, reduce manufacturing costs, and improve the quality, lifespan, and reliability of rotor blades by improving hole accuracy. [Structure] A long torsion rotor blade 1 is attached vertically to a work table 3 and a back plate 4 on a rotary table 2. The rotary table 2 is equipped with a rotary servo motor 5, the rocking table 6 at the bottom of the rotary table is driven by a rocking servo motor 7, and the table 8
are driven by an X-axis servo motor 9 and a Y-axis servo motor 10, and the headstock 14 is driven by a Z-axis servo motor 13, respectively. A main shaft 16, to which an electrode rod 15 having a discharge head at its tip is attached, moves up and down together with the headstock 14. Each servo motor is automatically controlled by the NC device 17 to perform highly accurate processing.

Description

[Detailed explanation of the idea]

0001

[Industrial application field]

This invention is a small-hole electric discharge that is applied to the processing of small holes such as cooling air holes in gas turbine rotor blades. Regarding processing machines.

0002

[Conventional technology]

As the gas turbine rotor blades became longer, the blade profile became more twisted in the radial direction. Twisted wings are used. The blade has many cooling holes drilled in the length direction. The holes are curved on the bottom side of the wing and straight on the top side. For this reason, conventional manufacturing focuses exclusively on precision. It relies on secret casting.

0003

[Problem that the idea aims to solve]

However, in conventional precision casting of this type, a large number of holes are required to create hollow parts that serve as cooling holes. It requires a thin and long core and a baseboard to support the core, and its low precision reduces yield. The cooling of the rotor blades was extremely poor, and the cooling of the rotor blades during use was uneven.

0004 The purpose of this invention is to provide a new small-hole electrical discharge machine that solves the above-mentioned problems. It is said that

[0005]

[Means to solve the problem]

To achieve the above purpose, it is applied to the processing of cooling holes in long torsional rotor blades of gas turbines. The small-hole electrical discharge machine of this invention rotates a rotary table equipped with moving blades. a rotary servo motor that rotates the rotary table, and a swing servo that swings the rotary table. The motor, the rotary servo motor and the swing servo motor are attached to the table. X-axis and Y-axis servo motors that move the bull in two-dimensional directions, front and back, left and right on a horizontal plane , moves the main shaft, to which an electrode rod with a discharge head is attached at the tip, vertically. a Z-axis servo motor, the rotary servo motor, and a swing servo motor; Controls each servo motor: X-axis servo motor, Y-axis servo motor, and Z-axis servo motor. It is characterized by being constructed by an NC device that controls the system.

[0006]

[Effect]

The small hole electric discharge machine of the present invention described above has a discharge head, which is a tool for electric discharge machining, in a vertical direction. At the same time, a rotor blade, which is a workpiece made of precision casting, was attached. The table can be moved two-dimensionally on a horizontal plane, forward and backward, left and right, as well as rotated and swung. This allows the straight cooling holes on the top side of the blade to be placed at different angles to the blade root rather than parallel to the blade. The curved cooling holes on the bottom side of long, large torsion blades are drilled with high accuracy. Can be opened without any communication.

[0007] Each servo motor for these operations is automatically controlled by a 5-axis NC device. It is configured so that it can be done.

[0008]

【Example】

An embodiment of the present invention will be described below with reference to the drawings. Figure 1 shows the cooling hole electrical discharge machining of a gas turbine long torsional rotor blade, which is an embodiment of the present invention. FIG. In the figure, the rotary blade 1, which is a torsion blade that is largely twisted, is rotary. The rotary table 2 is attached vertically to the work table 3 and back plate 4 on the table 2. is rotationally driven by a rotary servo motor 5. Also, the swing of the lower part of the rotary table The table 6 is driven to swing by a swing servo motor 7.

[0009] The table 8 to which the rotary servo motor 5 and the swing servo motor 7 are attached is The X-axis servo motor 9 drives in the X-axis direction, and the Y-axis servo motor 10 drives in the Y-axis direction. These are placed on a pedestal 11.

0010 Next, a Z-axis servo motor 13 is attached to the top of the column 12, and a ball screw The headstock 14 is driven up and down via the The attached spindle 16 moves up and down together with the headstock 14.

[0011] Note that the rotary servo motor 5, the swing servo motor 7, the X-axis servo motor 9, The Y-axis servo motor 10 and the Z-axis servo motor 13 are automatically controlled by the NC device 17. It will be done.

0012 The apparatus according to the first embodiment of the present invention described above is used to form cooling holes in gas turbine rotor blades. Regarding actual measurement results of specific machining accuracy when electrical discharge machining is performed, the diameter is approx. The processing accuracy of a 2mm cooling hole is ±0.1mm in position accuracy and ±0.1mm in hole dimension. it was under.

[0013]

[Effect of the idea]

According to the small hole electric discharge machine of the present invention, a long large torsional rotor blade with cooling holes for a gas turbine can be manufactured. At the time, the yield of precision casting improved by about 20%, and the cost was reduced even when hole processing costs were included. In addition, the quality, lifespan, and reliability of the rotor blade improve as the hole accuracy improves.

[Brief explanation of drawings]

FIG. 1 is a perspective view of a small-hole electrical discharge machine that is an embodiment of the present invention.

[Explanation of symbols] 1 Long torsional rotor blades of gas turbines 2 Rotary table 3 Work table 4 Back plate 5 Rotary servo motor 6 Rocking table 7 Swing servo motor 8 table 9 X-axis servo motor 10 Y-axis servo motor 12 Column 13 Z-axis servo motor 14 Headstock 15 Electrode rod 16 Main shaft 17 NC device

Claims (1)

[Scope of utility model registration request] 1. A rotary servo motor that rotates a rotary table to which moving blades are attached, a swing servo motor that swings the rotary table, and a table to which the rotary servo motor and swing servo motor are attached are moved back and forth on a horizontal plane.・X-axis and Y-axis servo motors that move in two-dimensional directions left and right, and Z-axis that moves the main shaft, to which an electrode rod with a discharge head at the tip is attached, in the vertical direction.
axis servo motor, and the rotary servo motor, swing servo motor, X-axis servo motor, Y-axis servo motor,
A small-hole electrical discharge machine for machining cooling holes in a long torsional rotor blade of a gas turbine, which is configured by an NC device that controls each servo motor of a Z-axis servo motor.