JPH0710417B2 - Blade material processing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of use] The present invention relates to a method for processing a blade material having a predetermined finishing allowance (for example, a blade material for a generator) from a material. In particular, the present invention relates to a blade material processing method suitable for highly accurately processing a material having an asymmetric cross-sectional shape of a blade.

[Prior Art] First, an example of a blade to which the present invention is applied will be described with reference to the drawings.

FIG. 6 is a perspective view showing an example of a blade to which the present invention is applied.

This blade has a blade length L, a blade width W, and a blade height H, and is composed of a blade portion 1 having an asymmetric cross-sectional shape in which the front end side is thicker than the rear end side in the rotational direction, and a tab tail portion 2. Has become. The wing portion 1 has a concave belly portion 1d and a convex back portion 1c, and also has a flat tip portion 1a and a root portion 1b connected to the tab tail portion 2. Tab tail part 2
Has a mounting portion 2a with a rotor body (not shown), and this mounting portion 2a is to be machine-finished.

A conventional method of processing a blade will be described.

Blades for generators are usually machined from square wood. In addition, a method has also been practiced in which a total die is used for die forging into a shape that leaves a predetermined finishing allowance, and then this is finished by machining. In particular, a press machine maker (Hasenclever) in West Germany has commercialized precision hot die forging using a screw press.
It has become possible to significantly reduce the number of mechanical finishing steps after this forging.

However, when cutting out from the above-mentioned square wood, the yield of the material is extremely poor, and a lot of resources are wasted. In addition, the die forging by the total die not only requires an excessive capital investment, but also has a short die life and an expensive die cost.

In order to solve the above-mentioned problems, a material having a predetermined finishing allowance is plastically worked from the material by free forging, and a blade having a predetermined dimension is machined from the material to be machined. Has been developed (Japanese Patent Application No. 59-120844).
Issue). The outline of this processing method will be described with reference to FIG.

FIG. 7 is a perspective view for explaining a conventional blade forging material forming method by free forging.

In this processing method, between the upper mold 7 for forming the abdomen and the lower mold 8 for forming the back part, the blade-processed portion 9a of the raw material 9 is sequentially pressure-molded from its root to its tip side. Is.

As for other processing methods of the blade material, the shape of the blade part is discussed as discussed in p. 453-456 of the Proc. With the upper and lower tools having the above, a blank is machined from a blank having a circular or rectangular cross section.

[Problems to be Solved by the Invention] In the above-mentioned conventional technique, when the material is cut out from a square bar, the yield of the material is extremely poor, and the die forging by the total die not only requires an excessive capital investment, The mold cost is expensive, and the method described in Japanese Patent Application No. 59-120844 is used.
Also, as in the method described in the collection of papers on spring working for plastic processing in 1985, when the material is processed by the upper and lower molds that have the shape of the blade, the shape of the blade processing part of the material is round. In the case of the shape, the strain during pressurization becomes non-uniform, which is not preferable from the viewpoint of the quality of the processed product. When the pressure position becomes unstable and the blade portion having an asymmetrical cross-sectional shape is processed, a rotational force is generated in the blade processing portion to cause twisting, which causes a problem that high-precision processing cannot be performed.

The present invention has been made to solve the above-mentioned problems of the prior art, and in the case of processing a raw material having a wing portion whose cross-sectional shape is asymmetric from a square raw material by free forging, in the initial stage of processing. An object of the present invention is to provide a blade material processing method that suppresses the rotation and twisting deformation of a material and that can be processed with high accuracy at low equipment cost and mold cost.

[Means for Solving the Problems] In order to achieve the above object, the configuration of the blade material processing method according to the present invention has a blade processing portion having a rectangular cross-sectional shape and a tab teal processing portion. In the blade material processing method of forming a wing portion having an abdomen and a back portion with a predetermined finishing allowance from the wing processing portion of a rectangular material, the pressing width in the longitudinal direction is the length of the wing portion. And a flat punch having a flat pressing surface whose width in the width direction is longer than the width in the width direction of the blade processing portion, and a back portion whose width direction shape is substantially the same as the back portion of the blade portion. Using the lower mold for molding,
With the rectangular material positioned so that the surface to be pressed of the blade processing portion is parallel to the pressing surface of the flat punch, the rectangular material is subjected to free forging to apply the rectangular material in the longitudinal direction of the flat punch. While moving by a smaller amount than the pressure width, the blade processing portion is locally locally pressurized to be preformed, and then the pressing width in the longitudinal direction is sufficiently shorter than the length of the blade portion and the width direction shape is An upper mold for forming an abdomen having a pressing surface having substantially the same shape as the abdomen of the wing, and a lower mold capable of molding the back of the wing facing the lower mold or the upper mold are used. By free-forging, by moving the preformed rectangular raw material by an amount smaller than the pressing width in the longitudinal direction of the upper die, locally pressurizing the blade pressurizing portion locally for finish forming. , Which is designed to mold the wings That.

More details are as follows.

In the sequential press forming of the blades, the rectangular material is first installed so as to be orthogonal to the pressing direction, and in preforming which is the initial step of pressing, the flat surface parallel to the surface to be pressed of the rectangular material is used. A flat punch having a surface and a predetermined lower die are sequentially pressed, and then, a predetermined upper die is sequentially pressed instead of the flat punch.

[Operation] In preforming, which is the initial step of pressurization, by sequentially pressing with a flat punch having a flat pressing surface, that is, a flat surface parallel to the pressed surface of the rectangular material, the width direction of the lower mold Even if the shape is asymmetric, since the pressed surface of the rectangular material and the flat surface are in full contact with each other, the flat punch side is hardly deformed, and the contact portion with the lower die is mainly deformed. Since the pressing surface of the flat punch is flat, the rectangular material does not rotate and twisting does not occur.

Next, after preforming in this way, finish forming is performed using a predetermined upper die instead of the flat punch, but at this time, since the formation of the back part of the wing has already progressed. When the contact portion with the upper die is deformed to form the abdomen of the blade, the desired blade with high accuracy is formed without the rectangular material rotating or twisting.

[Examples] Hereinafter, the present invention will be described with reference to Examples.

1 to 5 are for explaining a method for processing a material for a blade according to an embodiment of the present invention, and FIG. 1 is a front view showing a preforming state by a flat punch and a lower die. Fig. 2 is a side view thereof, Fig. 3 is a front view showing an initial state of finish forming by an upper die and the lower die, and Fig. 4 is a front view showing a final state thereof, Fig. 5 FIG. 6 is a perspective view showing a rectangular material used for processing.

First, the rectangular material 5 will be described with reference to FIG. This rectangular material 5 includes a blade processing portion 5a having a rectangular cross section,
It has a dovetail processing section 5b and a wing processing section.
The widthwise length of 5a is W '(which is, for example, equal to the blade width W in FIG. 6) and the thickness H' (which is larger than the blade height H).
And the length is a length L '(which is smaller than the blade length L) determined by the condition that the volume of the blade processing portion 5a and the volume of the blade portion 1 become substantially the same. Dovetail processing department
The shape and dimension of 5b are not directly related to the present invention, and thus the description thereof is omitted.

Next, a mold used for processing a raw material having a predetermined finishing allowance (for example, a finishing allowance of 1 mm) from the rectangular material 5 will be described.

In FIGS. 1 and 2, 6 is a flat punch, 4 is a lower die for forming the back portion, and these are used for preforming. The flat punch 6 has a pressing width W _{6 in the} longitudinal direction.
Is sufficiently shorter than the blade length, that is, the blade length L, and the widthwise pressing width is longer than the widthwise length W ′ of the blade processing portion 5a.
Are those having a planar pressing surface 6a, also the lower die 4 for back molding, the longitudinal direction of the pressing pressure width is W _7, the bottom surface of substantially the same shape in the width direction shape as the back 1c of the blade portion 1 4a.

In FIGS. 3 and 4, 3 is an upper mold for forming the abdomen, 4 is the same as the lower mold 4 for preforming, and these are used for finish forming. The upper die 3 has a pressing width in the longitudinal direction that is sufficiently shorter than the blade length L, and the shape in the width direction is the abdomen of the blade 1.
It has a pressing surface 3a having substantially the same shape as 1d.

An embodiment of the method for processing a material for a blade of the present invention will be described using the die having the above-described structure.

The pressing stroke of the flat punch 6 and the upper die 3 is determined. The entire stroke is the pressure surface 6a of the flat punch 6.
Stroke δ ₀ from the position where the blade abuts the upper surface of the unprocessed blade processing portion 5a (the solid line position in FIG. 1) until the blade processing portion 5a deforms and the lower surface reaches the bottom surface 4a of the lower die 4. And the stroke δ _N from this position to the position (the state of FIG. 4) at which the upper die 3 finishes the finish forming of the raw material,
4 strokes δ ₁ , δ ₂ , δ ₃ , δ ₄ (where δ ₁ +
δ ₂ + δ ₃ + δ ₄ = δ ₀ + δ _N ) and the first two strokes, that is, the first two steps are preforming, and the second two strokes, that is, the second two steps are finish forming. The feed pitch of the rectangular material 5 in the preforming and finish forming was set to p smaller than the pressing width of the flat punch 6 and the upper die 3 in the longitudinal direction.

First, the flat punch 6 or the upper die 3 is positioned above the lower die 4, and a predetermined stroke is applied to each of the flat punch 6 and the upper die 3 to press the blade processing portion 5a of the rectangular material 5 ( (Not shown), flat punch 6,
Set the lower mold 4. Raise the flat punch 6. The manipulator (not shown) grips the dovetail processing portion 5b of the rectangular material 5 and presses the root portion of the blade processing portion 5a connected to the tab tail processing portion 5b, that is, the first pressing position. Then, the workpiece pressure surface of the blade processing portion 5a is conveyed and positioned so as to be parallel to the pressure surface 6a of the flat punch 6. NC controller (not shown)
The moving amount (= feed pitch p) of the manipulator, the moving procedure, the strokes δ ₁ , δ ₂ , δ ₃ , δ ₄ at the moving destination, and the exchange command for the flat punch 6 and the upper die 3 are stored.

Here, when the press is turned on, the flat punch 6 descends, and the first pressurization is performed with the stroke δ ₁ . The flat punch 6 rises, and by the manipulator,
The rectangular material 5 is fed to the dovetail processing part 5b side and the pitch is p
Just move. The flat punch 6 descends, and the portion adjacent to the first pressurizing position is pressurized with the same stroke δ _{1 as the} previous _one (second pressurization). After the second pressurization, the same operation is sequentially repeated, and when the tip portion of the blade processing portion 5a is pressurized, the first step is completed. The second step has a stroke δ ₂ and is the same as the first step.
Pressing is sequentially repeated from the root portion to the tip portion connected to 5b, and the preforming is completed.

Next, the flat punch 6 is replaced with the upper die 3, and the rectangular material 5 is conveyed and positioned to the first pressing position in the same manner as in the preforming. The upper die 3 descends, and the first pressurization is performed with the stroke δ ₃ (FIG. 3). The upper die 3 rises and the manipulator moves the rectangular material 5 toward the dovetail processing portion 5b by the feed pitch p. The upper mold 3 is lowered, and the part adjacent to the first pressurizing position is pressed with the same stroke δ _{3 as the} previous one (second pressurization). After this second pressurization, the same operation is sequentially repeated, and when the tip portion of the blade processing portion 5a is processed, the third step is completed. In the fourth step, the stroke δ ₄ is applied in the same manner as in the third step, and when the finish forming is completed (FIG. 4), the press is turned off and a desired raw material is obtained.

A specific example is shown.

The product to be processed is a blade with the shape shown in Fig. 6, and its dimensions are blade length L = 200 mm, blade width W = 50 mm, blade height H = 25 mm, and the tip side is from the rear end side in the rotation direction. It is a straight blade with no twist, which has a thick asymmetric cross-sectional shape. The shape of the dovetail portion 2 is not directly related to the present invention, and therefore omitted. Further, details of the blade shape are also omitted because they are complicated. Material 13% Cr stainless steel.

The material has a finishing allowance of 1mm for the product to be processed, and the blade length is 210mm, which is 10mm longer than L.

In the rectangular material 5, the dimensions of the blade processing portion 5a are set such that the widthwise length W '= 50 mm, the thickness H' = 27 mm, and the length L '= 130 mm.

As for the die, the flat punch 6 is
6a longitudinal pressurizing pressure width W ₆ = 15 mm, and the width direction of the pressing pressure width 75m
m, the lower die 4 for forming the back part has a pressing width W ₇ = 2 in the longitudinal direction.
0 mm, the upper mold 3 for forming the abdomen has a pressing width of 15 mm in the longitudinal direction.
Is.

Preforming stroke δ ₁ = 10mm, δ ₂ = 10mm, Finishing stroke δ ₃ = 9mm, δ ₄ = 5.5mm (δ ₀ = 27mm,
δ _N = 7,5 mm), feed pitch p-10 mm (<W ₆ = 15 mm)
Was set and the blank was machined from the rectangular blank 5 (hot working at a working start temperature of 1050 ° C and a pressurizing end temperature of 800 ° C), and a desired blank having a finishing allowance of 1 mm was obtained. It was

According to the embodiment described above, the free forging method, which is inexpensive in equipment cost and die cost, can suppress uncertain twist and accurately process a blank material having an asymmetrical blade cross-sectional shape. The effect is that you can do it. As a result, the material yield can be significantly improved compared to the method by cutting,
Compared with die forging using a full die, it is advantageous in terms of equipment cost and die cost. In summary, this is as follows.

(A) It is possible to suppress the rotation, that is, the twisting, of the blade processing portion 5a due to the asymmetry of the cross-sectional shape of the blade, and it is possible to process a blank with high accuracy.

(2) Compared with cutting, the material yield can be significantly improved, and it is also advantageous in terms of equipment cost and die cost compared with die forging with a total die.

Although the lower die 4 is fixed and the flat punch 6 and the upper die 3 are moved up and down in the above-mentioned embodiment, all of them may be driven up and down. Similar effects can be obtained by arranging them on the left and right.

Further, in the above-mentioned embodiment, the same lower mold 4 was used for preforming and finish molding, but the upper mold 3 was used for finish molding.
If the back part can be molded facing
Other lower molds may be used.

Furthermore, in the above-described embodiment, the rectangular material 5 is intermittently fed by the feeding pitch p, but continuous feeding may be applied. However, in that case, it is necessary to taper the pressing surface of the mold to the longitudinal direction side of the rectangular material 5, that is, the side to which the material is fed.

Further, the feed pitch amount may be changed between the respective steps, and the feed direction may be fed so as to pressurize from the tip portion to the root portion, contrary to the above embodiment.

In the above embodiment, only one end side (tab tail processing portion 5b side) of the rectangular material 5 is gripped by the manipulator, but when the rectangular material 5 is long, in order to prevent bending that occurs during processing. It is desirable to grip both ends.

[Effects of the Invention] As described in detail above, according to the present invention, when a material having a wing portion whose cross-sectional shape is asymmetric is machined from a rectangular material by free forging, the material at the initial stage of processing. It is possible to provide a blade material processing method capable of suppressing the rotation and twisting deformation of the blade and capable of processing with high accuracy at low equipment cost and die cost.

[Brief description of drawings]

1 to 5 are for explaining a method for processing a material for a blade according to an embodiment of the present invention, and FIG. 1 is a front view showing a preforming state by a flat punch and a lower die. , Second
The figure is a side view thereof, FIG. 3 is a front view showing an initial state of finish forming by an upper die and the lower die, FIG. 4 is a front view showing its final state, and FIG. FIG. 6 is a perspective view showing a rectangular material used, FIG. 6 is a perspective view showing an example of a blade to which the present invention is applied, and FIG. 7 is a conventional blade forging material processing method by free forging. It is a perspective view for doing. 1 ... wing, 1c ... back, 1d ... abdomen, 3 ... upper mold, 4
...... Lower mold, 5 …… Rectangular material, 5a …… Wing processing part, 5b ……
Tab tail processing part, 6 ... Flat punch, 6a ... Planar pressure surface.

Front page continuation (72) Inventor Shinobu Watanabe 3-1-1 Sachimachi, Hitachi, Ibaraki Hitachi Ltd. Hitachi factory (72) Inventor Yoichi Kawada 3-1-1, Sachimachi, Hitachi, Ibaraki Hitachi Ltd., Hitachi Works (56) References Japanese Patent Laid-Open No. 61-1440 (JP, A)

Claims (1)

[Claims] 1. A wing processing section of a rectangular material having a wing processing section having a rectangular cross-sectional shape and a tab-till processing section,
In a blade material processing method for forming a wing portion with an abdomen and a back portion with a predetermined finishing allowance, the pressing width in the longitudinal direction is sufficiently shorter than the length of the wing portion, and the pressing in the width direction is performed. A flat punch having a planar pressing surface whose width is longer than the widthwise length of the blade processing part, and a widthwise shape using a lower mold for forming a back part having substantially the same shape as the back part of the blade part, With the rectangular material positioned so that the surface to be pressed of the blade processing portion is parallel to the pressing surface of the flat punch, the rectangular material is subjected to free forging to apply the rectangular material in the longitudinal direction of the flat punch. While moving by a smaller amount than the pressure width, the blade-processed portion was locally locally pressurized to be preformed, and then the pressing width in the longitudinal direction was sufficiently shorter than the length of the blade portion, and the shape in the width direction was An abdomen that has a pressing surface that has almost the same shape as the abdomen of the wings Using an upper die for shaping and a lower die capable of shaping the back portion of the wing portion facing the upper die or the upper die, the preformed rectangular material is formed by free forging. The blade is formed by moving the blade by a smaller amount than the pressing width of the upper die in the longitudinal direction and locally pressurizing the blade processing portion locally for finish forming. Pressing method for blanks.