JP2022178742A - Broach for turbine disc groove processing, and turbine disc groove processing method using the broach - Google Patents

Abstract

To provide a broach for turbine disc groove processing which allows groove processing to be performed without causing damages to a part of a turbine disc even in groove processing of a turbine disc with ribs, and to provide a turbine disc groove processing method using the broach.SOLUTION: A broach 1 for turbine disc groove processing comprises a base part 3 which supports a plurality of cutting edges 2a, 2b, 2c, 2d arrayed in a longitudinal direction, and bottom parts of the cutting edges 2a, 2b, 2c, 2d. In the broach, on the cutting edges 2a, 2b, 2c, 2d, a prescribed inclination angle θ is formed relative to a width direction of the broach 1 for turbine disc groove processing.SELECTED DRAWING: Figure 2

Description

The present invention relates to a turbine disk used in jet engines, power generators, etc., especially a broach dedicated to grooving on the circumference of a turbine disk provided with ribs on the inside or outside, and a turbine disk groove using the broach. It relates to the processing method.

In general, a cutting tool called a broach is used to machine gears on the inner or outer peripheral side of various parts (see Patent Document 1). Above all, when performing groove machining of a special shape along the circumference of a turbine disk used in a jet engine or the like, cutting is performed using a broach that conforms to the shape (Patent Documents 2 and 3 reference). FIG. 5 is a partial cross-sectional view of the peripheral portion of the turbine disk 300, FIG. 6 is a schematic bottom view of the peripheral portion of the turbine disk 300 shown in FIG. is shown in FIG.

JP-A-10-118837 JP-A-2001-234704 Japanese Patent Application Publication No. 2016-508888

However, if ribs 301, 401, 402 are provided on the inner or (and) outer side of turbine discs 300, 400 as shown in FIGS. , 401 and 402 may be cut only on one side of the cutting edge forming the broach. Further, as shown in FIG. 6, cutting may be performed in a state in which the center C11 in the width direction of the broach and the center C12 of the turbine disk form a predetermined angle α (also referred to as a skew angle). FIGS. 8 to 10 show schematic diagrams of grooving steps (first to third steps) of a turbine disk 500 using a conventional turbine disk grooving broach.

As described above, the turbine disk 500 has ribs 501 on its periphery and has a skew angle. When grooving is performed in this state, grooving is completed at one end of the rib 501 using a conventional turbine disk grooving broach 70 (71 to 73) as shown in FIG.

In the subsequent grooving using the conventional turbine disk grooving broaches 70 (71 to 74), the end portion for which grooving has been completed first forms a rib 501 as shown in FIG. 9 without being constrained by the broach. Grooving progresses in the central part and the end on the opposite side. At the same time, part of the rib 501 is generated as a large lump B.

After that, when the grooving of the opposite end is completed, the conventional turbine disk grooving broach 70 (71 to 75) is used as shown in FIG. Therefore, there is a problem that part of the turbine disk 500 is damaged by the mass B that is part of the rib 501 .

Therefore, the present invention provides a turbine disk grooving broach and a grooving method using the broach, which can perform grooving without partly damaging the turbine disk even in grooving a turbine disk having ribs. The task is to provide

A turbine disk grooving broach according to the present invention is a turbine disk grooving broach for grooving an outer peripheral surface of a turbine disk having rib-like projections. It is formed from an array of cutting edges and a base supporting the bottom of the plurality of cutting edges. It is desirable that these cutting edges are provided with a predetermined inclination angle with respect to the width direction of the broach, and this inclination angle is in the range of 0.5° or more and 10° or less. Also, the widthwise dimension of these cutting edges can be 50% or less of the widthwise dimension of the base.

Regarding the invention of the turbine disk grooving method using the turbine disk grooving broach, the width direction central axis of the turbine disk grooving broach and the radial direction central axis of the turbine disk are displaced from each other (separation A grooving method for grooving the outer peripheral surface of the turbine disk in a state where the turbine disk is placed.

Further, in the turbine disk grooving method using the turbine disk grooving broach, a first grooving step of grooving the turbine disk using a broach having a cutting edge with an inclination angle of 0°; a second grooving step of grooving the turbine disk using a turbine disk grooving broach having an inclination angle of 0.5° or more and 10° or less after the first grooving step; It can also be used as a method.

Furthermore, after the above-described second grooving step, the turbine disk grooving broach may be performed again using a broach for turbine disk grooving in which the inclination angle of the cutting edge of the broach is 0°.

By providing each cutting edge forming the turbine disk grooving broach of the present invention with an inclination angle within a predetermined range with respect to the width direction of the broach, even when grooving a turbine disk having ribs, the rib portion can be Since the cutting work is evenly performed on the turbine disk, the grooving can be performed without damaging a part of the turbine disk.

1 is a front view of a turbine disk grooving broach 1 of the present invention; FIG. 1 is a right side view of a turbine disk grooving broach 1 according to the present invention; FIG. 1 is a schematic diagram of a grooving form (first machining form) of a turbine disk 100 using a turbine disk grooving broach 10 of the present invention; FIG. FIG. 2 is a schematic diagram of a grooving mode (second machining mode) of a turbine disk 200 using the turbine disk grooving broach 20 of the present invention. 3 is a schematic cross-sectional view of a peripheral end portion (first embodiment) of turbine disk 300. FIG. FIG. 6 is a schematic bottom view of the peripheral end portion of the turbine disk 300 shown in FIG. 5; 4 is a schematic cross-sectional view of a peripheral end portion (second embodiment) of turbine disk 400. FIG. FIG. 5 is a schematic diagram of a grooving step (first step) of a turbine disk 500 using a conventional turbine disk grooving broach 70 (71 to 73). FIG. 5 is a schematic diagram of a grooving step (second step) of a turbine disk 500 using a conventional turbine disk grooving broach 70 (71 to 74). FIG. 5 is a schematic diagram of a grooving step (third step) of a turbine disk 500 using a conventional turbine disk grooving broach 70 (71 to 75).

An embodiment of a turbine disk grooving broach according to the present invention will be described below with reference to the drawings. A front view of a turbine disk grooving broach 1 according to a first embodiment of the present invention is shown in FIG. 1, and a right side view of the turbine disk grooving broach 1 is shown in FIG.

As shown in FIG. 1, a turbine disk grooving broach 1 of the present invention has a plurality of cutting edges 2a, 2b, 2c, and 2d arranged in the longitudinal direction (moving direction of the turbine disk grooving broach during cutting). ing. Base portions 3 for supporting the bottoms of these cutting edges 2a, 2b, 2c and 2d are formed on the pedestal portions of the plurality of cutting edges 2a, 2b, 2c and 2d.

2, each cutting edge 2a, 2b, 2c, 2d is inclined at a predetermined angle .theta. with respect to the width direction of the turbine disk grooving broach 1 (hereinafter referred to as an inclination angle). The angle of inclination θ is set in the range of 0.5° or more and 10° or less. The widthwise dimension h of these cutting edges 2a, 2b, 2c, and 2d may be 50% or less of the widthwise dimension H of the base portion 3.

Next, an invention of a turbine disk grooving method using the above-described turbine disk grooving broach will be described with reference to the drawings. FIG. 3 shows a schematic diagram of a grooving mode (first machining mode) of a turbine disk 100 using the turbine disk grooving broach 10 (11 to 13) of the present invention. The grooving of the present invention is formed from first and second grooving steps. In the first grooving step, as shown in FIG. 3, turbine disk grooving broaches 51 and 52 having cutting edges with an inclination angle of 0° are used to form grooves in a turbine disk 100 having ribs 101 on the outer peripheral surface. process.

Thereafter, the turbine disk grooving is performed using the turbine disk grooving broach 10 (11, 12, 13) having an inclination angle of the cutting edge in the range of 0.5° or more and 10° or less (second grooving step ). After the second grooving step, the turbine disk grooving broach 53 having a cutting edge with an inclination angle of 0° can be used to perform grooving of the turbine disk again.

By using this grooving method, the width direction central axis C1 of the turbine disk grooving broach shown in FIG. 3 and the radial direction central axis C2 of the turbine disk are shifted from each other (the skew angle α Grooving can also be performed in the state of having

Next, FIG. 4 shows a schematic diagram of a grooving mode (second machining mode) of the turbine disk 200 using the turbine disk grooving broach 20 (21 to 25) of the present invention. In the grooving method of the present invention, as shown in FIG. 4, the grooving method of the present invention first uses turbine disk grooving broaches 61 and 62 having cutting edges with an inclination angle of 0° to form grooves in the turbine disk 200, as in the first machining mode. Machining is performed (first grooving step). In this grooving, it is assumed that the center C3 in the width direction of the turbine disk grooving broach and the center axis C3 in the radial direction of the turbine disk coincide with each other.

After that, grooving of the turbine disk 200 is performed using the turbine disk grooving broach 20 (21 to 25) having a cutting edge with an inclination angle of 0.5° or more and 10° or less (second grooving step). . After the second grooving step, grooving of the turbine disk 200 is performed again using the turbine disk grooving broaches 63 and 64 having cutting edges with an inclination angle of 0°.

As shown in FIG. 4, in the grooving method of the present invention, grooves can be machined in the same width direction by combining a plurality of turbine disk grooving broaches 22 and 23 having cutting edges of different sizes in the width direction. can also be done.

1, 11 to 13, 21 to 25 Turbine disk grooving broach 2 (2a, 2b, 2c, 2d) Cutting edge 3 Base C1, C11 Central axis of turbine disk grooving broach C2, C12 Radial direction of turbine disk Center axis h Width dimension of cutting edge H Width dimension of base θ Inclination angle of cutting edge α

Claims (6)

A turbine disk grooving broach for grooving an outer peripheral surface of a turbine disk having rib-shaped projections, the broach for grooving a turbine disk comprising a plurality of cutting edges arranged in a longitudinal direction; A broach for grooving a turbine disk, comprising: a base supporting a bottom of a cutting edge, wherein the cutting edge is inclined at a predetermined angle with respect to the width direction of the broach. 2. A broach for machining a turbine disk groove according to claim 1, wherein said inclination angle is in the range of 0.5[deg.] or more and 10[deg.] or less. 3. A broach for machining a turbine disk groove according to claim 1, wherein the widthwise dimension of said cutting edge is 50% or less of the widthwise dimension of said base. 4. A turbine disk grooving method using the turbine disk grooving broach according to any one of claims 1 to 3, wherein a center axis in the width direction of the turbine disk grooving broach and the turbine disk A turbine disk grooving method, characterized in that grooving is performed on the outer peripheral surface of the turbine disk in a state in which the radial center axis of the turbine disk and the center axis of the turbine disk are shifted from each other. A turbine disk grooving method using the turbine disk grooving broach according to claim 1, wherein the turbine disk grooving broach having an inclination angle of 0° is used to perform grooving of the turbine disk. and, after the first grooving step, grooving the turbine disk using the turbine disk grooving broach having the inclination angle in the range of 0.5° or more and 10° or less. and a second grooving step. 6. The turbine disk groove according to claim 5, wherein after the second grooving step, the turbine disk grooving broach having the inclination angle of 0° is used to perform grooving of the turbine disk again. processing method.

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