JP2003165012A - Cutting method of thin member - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thin member cutting method allowing cutting of a thin member with an extremely thin thickness, without repeating machining from rough machining to finishing or using a special fixture. <P>SOLUTION: A material 4 having a sufficient removal allowance for a desired thin member 1 is prepared, cutters 6 and 7 that do not interfere with curvature of a recess of the material are prepared, and the material is cut by the cutters. The cutter 6 is an end mill having a substantially flat bottom and cuts the material with the end mill tilted against the machining surface. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for cutting a thin member having a very small thickness such as a blade of a turbine or a compressor.

[0002]

2. Description of the Related Art When a very thin member (hereinafter referred to as a thin member) such as a blade of a turbine or a compressor is machined out, if the cutting allowance is large and the cutting resistance is large, the cutting resistance causes the thinning. The member itself deforms and escapes, causing so-called chattering vibrations and making machining impossible.

[0003]

Therefore, it has been considered impossible to cut such a thin member conventionally, and it is necessary to reduce the cutting allowance and repeat the processing from roughing to finishing. . Further, in this case, in the case of a thin-walled member having a complicated shape such as a thin blade of a turbine or a compressor, a plurality of mounting jigs 2 for supporting the thin-walled member 1 being processed are prepared as illustrated in FIG. It was necessary to use a ball end mill 3 or the like to alternately and repeatedly grind the front and back of a thin member (for example, thin blade) little by little. Therefore, machining such a thin member requires a large number of jigs,
There is a problem that the processing time is long and, as a result, the processing cost is high.

The present invention was devised to solve such problems. That is, an object of the present invention is to provide a thin-walled member having a very thin thickness that can be cut without repeating the processing from roughing to finishing and without using a special jig. It is to provide a cutting method.

[0005]

According to the present invention, a material having a sufficient margin for a desired thin member is prepared, and a cutter that does not interfere with the curvature of the recess of the material is prepared. There is provided a method for cutting a thin-walled member, which comprises cutting the material. According to the method of the present invention described above, the material can be cut, and the cutting can be performed with a large incision without the cutter interfering with the curvature of the recess of the material.

According to a first preferred embodiment of the present invention,
The cutter is an end mill having a substantially flat bottom surface, and the end mill is inclined with respect to a processing surface to cut the material. According to this method, the end mill can be machined with a slight inclination from the right angle to the blade surface, thereby completing the blade surface with good finish roughness even when machining with a large feed pitch.

According to a second preferred embodiment of the present invention, the cutter is a side cutter which rotates about an axis parallel to the longitudinal direction of the material, and the radius of the side cutter is set to the above range. The material is cut by setting the radius smaller than the minimum radius of the thin member. By this method, cutting can be performed with a large depth of cut without controlling the rotation axis of the tool. Therefore, it is possible to apply an NC processing apparatus having few numerical control axes.

Also, supporting at least one end of the material,
It is preferable to manufacture the thin member by cutting the material while turning around the material from the other end side. According to this method, an unmachined high-rigidity material having a large surplus (removal allowance) is supported at at least one end in the longitudinal direction, and the cutting force is applied from the other end to the rigid support side. Since they are facing each other, the cutting can be done with a large cut. In addition, since the finished shape can be processed in one time, and the cutting force does not work in the thickness direction of the thin member (direction perpendicular to the blade surface), there is little deformation of the material and chatter vibration does not occur, which is good. The machined surface roughness can be obtained, for example, the dimensional accuracy of the leading edge and the trailing edge of the blade surface can be ensured, and the round hand finishing is not necessary.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of the present invention will be described below with reference to the drawings. In addition, in each figure, the common part is denoted by the same reference numeral, and the duplicated description will be omitted.

FIG. 1 shows a first method of cutting a thin member according to the present invention.
It is a figure which shows embodiment and FIG. 2 is sectional drawing in the AA line of FIG. As shown in FIG. 1, in the method of the present invention, first, a material 4 having a shape with a sufficient margin for a desired thin member 1 (for example, a thin blade) and high rigidity is prepared. The rigidity of this material is set, at least at the stage of the material, so that the deformation due to the cutting resistance is sufficiently small even if the desired thin member 1 is cut out by one-time cutting.

In the first embodiment, the processing device has five
The axis NC controller is used. That is, an end mill 6 having a flat bottom is used as a tool, which is controlled in three axes x, y, and z, and the inclination θ of its rotation axis is numerically controlled. Further, at least one end (both ends in this example) of the material 4 in the longitudinal direction is supported by the fixture 11 (and the center support 12),
The rotary table 13 numerically controls the rotation angle α about the longitudinal axis y of the material 4.

The end mill 6 having a flat bottom is inclined at an angle of θ (3 to 5 °) with respect to the machined surface so that the bottom surface contacts the machined surface of the desired thin member 1 at one point. . That is, the radius of the end mill 6 is set smaller than the desired minimum radius of the thin member 1, and the bottom surface of the thin member 1 is numerically controlled so that the bottom surface does not interfere with the machined surface except at the machining point. Always 3-5 for the machined surface
Control so that the angle becomes °.

With the above-mentioned structure, in the method of the present invention, the rotation angle α, the inclination angle θ, and the position (x, y, z) of the tool are numerically controlled to obtain a desired value from the other end side in the longitudinal direction of the material 4. While turning the thin member 1 around the material, the material is cut to produce a thin member. It is preferable to machine a desired thin member to the finished shape by cutting once.

FIG. 3 is a diagram showing the relationship between the tool and the machined surface in FIG. 1. FIG. 3A is a diagram showing the relationship between the end mill 6 and the machined surface of the thin member 1, and FIG. Is.
As described above, by numerically controlling the inclination angle θ so that the bottom surface of the end mill 6 always forms an angle of 3 to 5 ° with respect to the processing surface of the thin member 1, the processing pitch P is relatively large (for example, 1 (2 mm), the caps, which is the uncut portion of the tool, can be reduced as shown in the figure. As a result,
A machined surface with good finish roughness can be obtained even when machined with a relatively large feed pitch. For example, the tool r on the bottom shoulder of the end mill 6 is about 0.5 to 1.0 mm, and the processing pitch P is 1 m.
When m, the average roughness Ra of the machined surface was about 0.8 μm or less, and a smooth surface requiring almost no manual finishing was obtained.

4A and 4B are views showing a second embodiment of the method for cutting a thin member according to the present invention. FIG. 4A is a side view and FIG. 4B is a sectional view taken along line BB. In this example, a 4-axis NC control device is used as the processing device. That is, a side cutter 7 that rotates about an axis parallel to the longitudinal direction of the material is used as a tool, and this is controlled in three axes x, y, and z (the inclination of the rotation axis is not controlled). The material 4 is supported by at least one end in the longitudinal direction, and the rotation angle α is numerically controlled about the longitudinal axis y of the material 4. Further, the side cutter 7 sets the radius of the side cutter smaller than the minimum radius of the desired thin member 1 in order to avoid interference with the desired thin member 1. Other methods are the same as those in the first embodiment shown in FIG.

According to the above-described method for cutting a thin member of the present invention, the unmachined high-rigidity material 4 having a large remaining amount (removal allowance) is supported at at least one end in the longitudinal direction,
Since the cutting force is directed from the other end to the rigid support side, the cutting can be performed with a large cut. In addition, since the finished shape can be processed in one time, and the cutting force is not directed in the thickness direction of the thin member 1 (direction perpendicular to the blade surface), deformation of the material is small and chatter vibration does not occur.
Good machined surface roughness can be obtained, for example, the dimensional accuracy of the leading edge and the trailing edge of the blade surface can be ensured, and hand finishing by rounding is unnecessary.

Further, by using the end mill 6 and processing, for example, a slight inclination from the right angle to the blade surface, it is possible to complete the blade surface with good finish roughness even when processing with a large feed pitch.

Further, by using the side cutter 7, it is possible to perform cutting with a large cut without controlling the rotary axis of the tool. Therefore, it is possible to apply an NC processing apparatus having few numerical control axes.

It should be noted that the present invention is not limited to the above-mentioned embodiments, and can be variously modified without departing from the gist of the present invention.

[0020]

As described above, the present invention has the following features. 1. A thin member (for example, a thin blade) is shaved once and processed without intermediate finishing, thereby eliminating the occurrence of chattering. At this time, while turning around the blade, processing is performed from the tip to the root. 2. In order not to generate chatter, the blade is tilted slightly so that it does not interfere with the curvature of the depression on the ventral side and receives cutting resistance in the direction of the base of the material. 3. Even if the pitch is increased, the cusp left uncut from the cutter is eliminated, reducing hand finishing. 4. It is possible to improve the degree of finishing by reducing the radius of the cutter, reducing the cutting resistance that causes the rattle perpendicular to the processing surface (for example, the blade surface) of the thin-walled member, and reducing the cusp.

Therefore, the method for cutting a thin member of the present invention is
It has an excellent effect that a thin member having an extremely thin thickness can be cut without repeating the processing from roughing to finishing and without using a special jig.

[Brief description of drawings]

FIG. 1 is a diagram showing a first embodiment of a thin member cutting method of the invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a relationship diagram between a tool and a machining surface in FIG.

FIG. 4 is a diagram showing a second embodiment of a thin member cutting method of the invention.

FIG. 5 is a schematic diagram showing a conventional method for cutting a thin member.

[Explanation of symbols]

1 thin member, 2 mounting jig, 3 ball end mill, 4 material, 6 end mill, 7 side cutter,
8 cusp, 11 mounting tool, 12 center support tool, 1
3 turntable

Continued front page    (72) Inventor Kiyoshi Fujikake             Stone, 3-5-1, Mukodai-cho, Nishi-Tokyo, Tokyo             Kawashima Harima Heavy Industries Ltd. Tanashi factory (72) Inventor Shozo Nakano             3934 Inatomi, Tatsuno-cho, Kamiina-gun, Nagano Ishikawajima             General-purpose machinery Co., Ltd.

Claims (4)

[Claims] 1. A material having a sufficient allowance for a desired thin member is prepared, a cutter that does not interfere with the curvature of the recess of the material is prepared, and the material is cut by the cutter. Method for cutting thin-walled member. 2. The method for cutting a thin member according to claim 1, wherein the cutter is an end mill having a substantially flat bottom surface, and the end mill is inclined with respect to a processing surface to cut the material. . 3. The cutter is a side cutter which rotates about an axis parallel to the longitudinal direction of the material, and the radius of the side cutter is set to be smaller than the minimum radius of the thin-walled member. The method for cutting a thin member according to claim 1, wherein the cutting is performed. 4. The thin member is manufactured by supporting at least one end of the material and cutting the material while rotating around the material from the other end side to produce a thin member. A method for cutting a thin member according to.