阅读说明：本技术 对长条材料加工自由曲面的方法 (Method for processing free-form surface of long strip material ) 是由 中西卓也 清水信男 浅香晴彦 俣野和弥 于 2018-06-27 设计创作，主要内容包括：在把持凸部3及叶片根部4的状态下对长条材料1加工自由曲面之后,在通过释放对凸部3的把持而释放加工时的应变时,长条材料1整体发生变形,由此,凸部3从被把持的位置A向释放了应变的位置B移动。确定以由长条材料1的自重引起的长条材料1的变形量对位置B进行修正后的位置即再次把持位置C,并在再次把持位置C对凸部3再次进行把持,对长条材料1再次加工自由曲面。(After the free-form surface is processed on the long material 1 in a state where the convex portions 3 and the blade root portions 4 are gripped, when the strain at the time of processing is released by releasing the grip on the convex portions 3, the entire long material 1 is deformed, and thereby the convex portions 3 move from the gripped position a to the strain-released position B. The re-gripping position C, which is a position where the position B is corrected by the amount of deformation of the long material 1 due to the own weight of the long material 1, is determined, and the convex portion 3 is re-gripped at the re-gripping position C, so that the free-form surface is machined again on the long material 1.)

1. A method for processing a free-form surface of an elongated material,

the strip material having one end region and the other end region in the length direction,

the method comprises the following steps:

a step of gripping the one end region and the other end region;

a first processing step of processing a free-form surface in the long material while holding the one end region and the other end region;

releasing the grip on the one end region;

a step of determining a re-gripping position in which a position of the one end region in a state where the gripping of the one end region is released is corrected by a deformation amount of the long material due to a self weight of the long material;

a step of re-gripping the one end region at the re-gripping position; and

and a second processing step of processing a free-form surface in the long material after the one end region is gripped again.

2. The method of claim 1, wherein,

the amount of deformation of the elongated material caused by the own weight of the elongated material is determined in advance by analysis or experiment,

in the step of determining the re-gripping position, a position shifted from a position of the one end region in a state where gripping of the one end region is released by an amount corresponding to the deformation amount is determined as the re-gripping position.

3. The method of claim 1 or 2,

the deformation amount is a difference between a position of the one end region relative to the other end region in a state where the elongated material is oriented in a horizontal direction and a position of the one end region relative to the other end region in a state where the elongated material is oriented in a vertical direction.

4. The method of claim 1, wherein,

further comprising a step of vertically orienting the elongated material from which the grip on the one end region is released after the step of releasing the grip on the one end region,

in the step of determining the re-gripping position, a position of the one end region relative to the other end region when the elongated material from which the one end region is released from being gripped is directed in a vertical direction is determined as the re-gripping position.

5. The method of any one of claims 1 to 4,

after the second processing step, the step of releasing the grip on the end region to the second processing step is repeated at least once.

6. The method of any one of claims 1 to 5,

after the second processing step, a step of performing surface processing treatment on the free-form surface is further included.

7. The method of claim 6, wherein,

the amount of deformation of the elongated material due to the residual stress caused by the surface processing is predicted in advance, and the free-form surface is processed in the second processing step in consideration of the predicted value.

8. The method of any one of claims 1 to 7,

the one end region of the long material has a projection projecting from the one end region, and the projection is gripped when the one end region is gripped.

9. The method of any one of claims 1 to 8,

the product obtained by processing the free-form surface of the strip material is a blade of a rotary machine.

10. The method of claim 9, wherein,

the one end region and the other end region are gripped so that a chord direction is oriented in a vertical direction at a blade tip end side of the blade.

Technical Field

The invention relates to a method for processing a free-form surface on an elongated material.

Background

Conventionally, when a turbine blade is machined from a long material, rough machining and finish machining are performed while maintaining a state in which a blade root portion and a blade end portion are held. In this case, the long bar material is strained during rough machining, and when the turbine blade is machined in this state directly, the accuracy of the final finished state of the turbine blade deteriorates. Although the machining of the turbine blade is not involved, patent document 1 describes: when the long material is machined, the holding of one end of the long material is released after the rough machining is completed, the strain of the long material is released, and the one end of the long material is gripped again in a shape in which the strain is released, and the finish machining is performed.

Prior art documents

Patent document

Patent document 1: japanese laid-open patent publication No. 10-76437

Disclosure of Invention

Problems to be solved by the invention

However, since the long material is generally held so as to be arranged in the horizontal direction when the long material is processed, even if one end of the long material is released after the rough processing is completed in this state, the strain during the rough processing can be released, but the stress due to the deformation of the long material itself supported by the cantilever remains at the other end. Even if one end of the long material is gripped again and finished in a state where the stress due to the deformation of the long material itself by its own weight remains, the final finished state of the product obtained by processing the free-form surface on the long material may not be as desired.

In view of the above, an object of at least one embodiment of the present invention is to provide a method of processing a free-form surface in an elongated material, in which accuracy of a final finish state of a product obtained by processing the free-form surface in the elongated material is improved.

Means for solving the problems

(1) In the method of processing a free-form surface in an elongated material according to at least one embodiment of the present invention,

the strip material having one end region and the other end region in the length direction,

the method comprises the following steps:

a step of gripping the one end region and the other end region;

a first processing step of processing a free-form surface in the long material while holding the one end region and the other end region;

releasing the grip on the one end region;

a step of determining a re-gripping position in which a position of the one end region in a state where the gripping of the one end region is released is corrected by a deformation amount of the long material due to a self weight of the long material;

a step of re-gripping the one end region at the re-gripping position; and

and a second processing step of processing a free-form surface in the long material after the one end region is gripped again.

According to the method of the above (1), since the second processing step is performed in a state where the strain of the long material generated in the first processing step and the stress accompanying the deformation of the long material due to the own weight of the long material are released, the accuracy of the final finish state of the product obtained by processing the free-form curved surface on the long material can be improved.

(2) In several embodiments, in addition to the method of (1) above,

the amount of deformation of the elongated material caused by the own weight of the elongated material is determined in advance by analysis or experiment,

in the step of determining the re-gripping position, a position shifted from a position of the one end region in a state where gripping of the one end region is released by an amount corresponding to the deformation amount is determined as the re-gripping position.

According to the method of the above (2), in the step of determining the re-gripping position, it is not necessary to separately determine the amount of deformation of the long material due to the weight of the long material, and the method of processing a free-form surface on the long material can be performed quickly.

(3) In several embodiments, in addition to the method of (1) or (2) above,

the deformation amount is a difference between a position of the one end region relative to the other end region in a state where the elongated material is oriented in a horizontal direction and a position of the one end region relative to the other end region in a state where the elongated material is oriented in a vertical direction.

According to the method of the above (3), the amount of deformation of the long material due to the weight of the long material can be accurately and easily obtained.

(4) In several embodiments, in addition to the method of (1) above,

further comprising a step of vertically orienting the elongated material from which the grip on the one end region is released after the step of releasing the grip on the one end region,

in the step of determining the re-gripping position, a position of the one end region relative to the other end region when the elongated material from which the one end region is released from being gripped is directed in a vertical direction is determined as the re-gripping position.

According to the method of the above (4), since the re-gripping position in consideration of the deformation due to its own weight is determined for each long material, the accuracy of the final finished state of the product formed by processing the free-form surface on the long material can be further improved.

(5) In some embodiments, in addition to any one of the methods (1) to (4) above,

after the second processing step, the step of releasing the grip on the end region to the second processing step is repeated at least once.

According to the method of the above (5), even when the step of processing a free-form surface is repeated, the free-form surface can be processed again in a state where the strain generated in the processing of the free-form surface and the stress accompanying the deformation due to its own weight are released, and therefore the accuracy of the final finished state of the product obtained by processing the free-form surface on the long material can be improved.

(6) In some embodiments, in addition to any one of the methods (1) to (5) above,

after the second processing step, a step of performing surface processing treatment on the free-form surface is further included.

According to the method of the above (6), the mechanical properties of a product obtained by processing a free-form surface on an elongated material can be improved.

(7) In several embodiments, in addition to the method of (6) above,

the amount of deformation of the elongated material due to the residual stress caused by the surface processing is predicted in advance, and the free-form surface is processed in the second processing step in consideration of the predicted value.

According to the method of the above (7), since the strain generated in the surface processing treatment is applied to the long material on which the free-form surface is processed, the final finished state of the product in which the free-form surface is processed on the long material becomes as desired, the accuracy of the final finished state of the product in which the free-form surface is processed on the long material can be improved.

(8) In some embodiments, in addition to any one of the methods (1) to (7) above,

the one end region of the long material has a projection projecting from the one end region, and the projection is gripped when the one end region is gripped.

According to the method of the above (8), since the projection projects from the one end region, the grip is easy, and the processing is simple.

(9) In some embodiments, in addition to any one of the methods (1) to (8), the product obtained by processing a free-form surface on the elongated material is a blade of a rotary machine.

According to the method of the above (9), it is possible to provide a blade for a rotary machine in which the accuracy of the final finish state is improved.

(10) In several embodiments, in addition to the method of (9) above,

the one end region and the other end region are gripped so that a chord direction is oriented in a vertical direction at a blade tip end side of the blade.

Since the thickness of the blade tip side of the blade is thinner than the thickness of the blade root side, the blade tends to be easily deformed when a force in an out-of-plane direction (a direction perpendicular to the chord direction) is applied to the blade tip side. However, according to the method of the above (10), when the grip on the one end region is released and only the other end region is supported in the cantilever manner, the force based on the self weight of the blade acts in the in-plane direction (chord direction) of the blade on the blade tip side, and the deformation caused by the self weight of the blade is suppressed. When the deformation due to the weight of the blade is suppressed, the deviation of the re-gripping position of the one end region due to the individual difference of the blade is reduced, and therefore, the stress accompanying the deformation due to the weight of the long material can be effectively released when the one end region is re-gripped.

Effects of the invention

According to at least one embodiment of the present invention, the accuracy of the final finished state of the product obtained by processing the free-form curved surface on the elongated material can be improved by performing the second processing step in a state in which the strain of the elongated material generated in the first processing step and the stress accompanying the deformation of the elongated material due to the own weight of the elongated material are released.

Drawings

Fig. 1 is a view showing a long material used in the method according to one embodiment of the present invention.

FIG. 2 is a flow chart of a method of an embodiment of the present invention.

Fig. 3 is a perspective view of a first grip portion gripping a blade root in the method according to the embodiment of the present invention.

Fig. 4 is a front view of a second grip portion gripping a convex portion in the method according to the embodiment of the present invention.

Fig. 5 is a view of the second grip portion of fig. 4 as viewed from the direction of arrow V.

Fig. 6 is a diagram showing a position of the convex portion when the convex portion is released from being gripped after the first processing step is completed and a re-gripping position where the convex portion is re-gripped in the method according to the embodiment of the present invention.

Fig. 7 is a flow chart of a method of another embodiment of the present invention.

Fig. 8 is a diagram for explaining the deformation of the long material corresponding to the predicted value of the deformation amount of the long material due to the residual stress caused by the shot peening.

Detailed Description

Hereinafter, embodiments of the invention will be described with reference to the drawings.

However, the scope of the present invention is not limited to the following embodiments. The dimensions, materials, shapes, relative arrangements and the like of the constituent members described in the following embodiments are not intended to limit the scope of the present invention to these, but are merely illustrative examples.

The method according to several embodiments of the present invention will be described by taking as an example a method of manufacturing a blade of a rotary machine such as a turbine or a compressor by processing a free-form surface in a long material. The product obtained by processing a free-form surface on a long material is not limited to a blade of a rotary machine.

As shown in fig. 1, the long material 1 processed with the free-form surface has one end region 1a and the other end region 1b in the longitudinal direction thereof. The one end region 1a includes a shield 2, and a projection 3 projecting from the shield 2 is provided on the shield 2. The convex portion 3 may have a substantially rectangular parallelepiped plate shape. The one end region 1a is not limited to a protruding convex shape as long as it has a reference surface for machining or measurement. The other end region 1b contains the finished product, i.e. the blade root 4 of the blade.

A method according to an embodiment of the present invention will be described based on the flowchart of fig. 2. First, in step S1, the projection 3 and the blade root 4 are gripped by jigs. An exemplary embodiment of the gripping of each of the projection 3 and the blade root 4 will be described in detail below. However, the structure and the method of holding the jig for holding the convex portion 3 and the blade root portion 4 may be arbitrary, and are not limited to the following embodiments.

As shown in fig. 3, one embodiment of the first grip portion 10 as a jig for gripping the blade root 4 includes: a base 11; a support base 13 that supports the blade root 4 from below; and two pressure plates 12, 12 that clamp the blade root 4 with the support table 13. The support base 13 is formed with a groove corresponding to the groove of the blade root 4. Each presser plate 12 is also formed with a groove corresponding to the groove of the blade root 4. In a state where the blade root 4 is sandwiched between the pressure plate 12 and the support base 13, the pressure plate 12 is fixed to the support base 13 by the bolts 14, whereby the blade root 4 is gripped by the first grip portion 10.

As shown in fig. 4 and 5, one embodiment of the second gripping portion 20 as a jig for gripping the projection 3 includes: a base portion 21; a rotation mechanism 61 that rotates relative to the base 21; a first slide mechanism part 62 that slides linearly with respect to the rotation mechanism part 61; a second slide mechanism section 63 that slides linearly with respect to the first slide mechanism section 62 in a direction perpendicular to the sliding direction of the first slide mechanism section 62; and a gripping mechanism 64 provided in the second slide mechanism 63 and gripping the projection 3.

The jig for gripping the convex portion 3 is not limited to the below-described gripping jig, as long as it has a mechanism that slides in the rotation direction E and the directions F and G (see fig. 4).

As shown in fig. 5, the rotation mechanism 61 includes a bush 22 fixed to the base 21 and a platen 23 provided to be rotatable with respect to the bush 22. The platen 23 rotates in the direction of arrow E (fig. 4) with respect to the base 21 by rotating with respect to the bushing 22.

The first slide mechanism 62 includes a first receiving table 24 provided slidably with respect to the platen 23, and a first slide portion 65 for sliding the first receiving table 24. The first slide portion 65 includes a frame 31 fixed to the platen 23 and a set screw 32 inserted into a through hole 31a formed in the frame 31. A thread groove is formed in the inner peripheral surface of the through hole 31a, and is screwed with the thread groove of the tightening screw 32. The tip end portion of the tightening screw 32 is coupled to the first receiving base 24, and by displacing the position of the tightening screw 32 with respect to the housing 31, the first receiving base 24 linearly slides in the direction of the arrow F in accordance with the displacement of the tightening screw 32.

The second slide mechanism 63 includes a second receiving table 25 provided slidably with respect to the first slide mechanism 62, and a second slide portion 66 for sliding the second receiving table 25. As shown in fig. 4, the second sliding portion 66 includes a frame 33 fixed to the first pedestal 24 and a set screw 34 inserted into a through hole 33a formed in the frame 33. A thread groove is formed in the inner peripheral surface of the through hole 33a, and is screwed with the thread groove of the tightening screw 34. The tip end portion of the tightening screw 34 is coupled to the second receiving base 25, and by displacing the position of the tightening screw 34 with respect to the housing 33, the second receiving base 25 linearly slides in the direction of the arrow G in accordance with the displacement of the tightening screw 34. The direction of arrow G is perpendicular to the direction of arrow F.

As shown in fig. 5, the second receiving base 25 includes a base portion 25a and a protruding portion 25b, and the protruding portion 25b has a length in the horizontal direction shorter than the base portion 25a and protrudes from the base portion 25 a. The gripping mechanism 64 includes a plate-shaped pressing plate 41 and two weights 43 having an L-shaped cross section. The pressure plate 41 is fixed to the front surface 25b1 of the protruding portion 25b facing the base portion 25a by bolts 42, and the one end portion 43a of each weight 43 is fixed to the protruding portion 25b by bolts 44 so as to abut against the front surface 25a1 of the base portion 25a and the side surface 25b2 of the protruding portion 25 b. Here, the front face 25a1 is a face provided with the protruding portion 25b, and the side face 25b2 is a face connecting the front face 25a1 and the front face 25b 1. In a state where the shim plate 45 having an appropriate thickness and the convex portion 3 of the long material 1 are inserted between the presser plate 41 and the weight 43, the weight 43 is fixed to the protruding portion 25b by the bolt 44, whereby the convex portion 3 is gripped by the second gripping portion 20 so as to be sandwiched between the presser plate 41 and the weight 43.

As shown in fig. 4, the protruding portion 25b (see fig. 5) is provided with a support portion 51 and a frame 53. When convex portion 3 is sandwiched between pressure plate 41 and weight 43, support portion 51 is positioned below convex portion 3, and frame 53 is positioned above convex portion 3. The support portion 51 supports the lower end surface 3a of the projection 3 via the pad 52. The frame 53 has a through hole 53a, a screw groove for screwing the screw groove of the bolt 54 is formed in the inner peripheral surface of the through hole 53a, and the bolt 54 is inserted into the through hole 53a, and the tip of the bolt 54 is pressed against the upper end surface 3b of the projection 3, whereby the projection 3 is held between the support portion 51 and the bolt 54.

Here, it is preferable to grip the convex portion 3 and the blade root portion 4 so that a chord direction L (fig. 1) connecting the front edge 6 and the rear edge 7 faces in the vertical direction on the blade tip side of the finished product, i.e., the blade. Since the thickness of the blade tip side of the blade is thinner than the thickness of the blade root 4 side, the blade tip side tends to be easily deformed when a force in an out-of-plane direction (a direction orthogonal to the chord direction) is applied to the blade tip side. When the grip of the convex portion 3 is released and only the blade root portion 4 is supported by the cantilever, a force based on the self weight of the blade acts in the in-plane direction (chord direction) of the blade on the blade tip side, and deformation due to the self weight of the blade is suppressed.

In the method according to the embodiment of the present invention, the convex portion 3 is gripped so as to be sandwiched between the support portion 51 and the bolt 54 by the weight 43 and the presser plate 41 from the direction perpendicular to the longitudinal direction connecting the one end region 1a and the other end region 1b of the long material 1. Similarly, the blade root 4 is gripped so as to be sandwiched between the presser plate 12 and the support base 13 from a direction perpendicular to the longitudinal direction connecting the one end region 1a and the other end region 1b of the long material 1. That is, the long material 1 is not applied with the pressing forces in the direction from the one end region 1a toward the other end region 1b and in the direction from the other end region 1b toward the one end region 1 a. In order not to apply such a pressing force to the long material 1, as shown in fig. 5, the convex portion 3 is held by the second holding portion 20 so that the gap 30 is provided between the convex portion 3 and the front surface 25b1 of the projecting portion 25b of the second receiving base 25. By gripping the protruding portion 3 and the blade root portion 4 so as not to apply such a pressing force to the long material 1, a buckling phenomenon in which a weak portion such as a portion having a small thickness of the long material 1 is bent can be avoided.

As shown in fig. 2, after step S1 is completed, a first processing step (step S2) of processing a free-form surface of the long material 1 while gripping the convex portions 3 and the blade root portions 4 is performed. The strip material 1 is strained when the free curved surface is machined. In order to release the strain, the grip of the projection 3 is released after the first processing step is finished (step S3).

As shown in fig. 6, when the strain is released by releasing the grip of the projection 3, the entire long material 1 is deformed, and the projection 3 moves from the gripped position a to the strain-released position B. Then, the convex portions 3 are gripped again in order to further machine the free-form surface to the long material 1, but since the state in which the gripping of the convex portions 3 is released is a state in which the blade root portions 4 (see fig. 1) are cantilever-supported by the first gripping portions 10, the long material 1 is deformed by its own weight. Therefore, when the convex portion 3 is gripped again at the position B where the strain caused by the first processing step is released and the free curved surface is processed again on the long material 1, the long material 1 is processed in a state where the stress due to the deformation caused by the own weight of the long material 1 remains, and the accuracy of the final finished state of the blade is sometimes not as desired. Therefore, it is necessary to determine a re-gripping position C (step S4 in fig. 2) which is a position where the position B is corrected by the amount of deformation of the long material 1 due to the own weight of the long material 1, and to re-grip the projection 3 at such a re-gripping position C. The procedure for determining the re-gripping position C will be described below.

In one embodiment, the step of determining the re-gripping position may determine a deformation amount due to the weight of the long material 1 in advance, and may set a position shifted from the position B in fig. 6 by an amount corresponding to the deformation amount as the re-gripping position C. The amount of deformation can be determined analytically or experimentally. In the determination based on the experiment, for example, a difference between the position of the one end region 1a relative to the other end region 1b in a state where the long material 1 is oriented in the horizontal direction and the position of the one end region 1a relative to the other end region 1b in a state where the long material 1 is oriented in the vertical direction may be obtained, and the difference may be used as the deformation amount. More specifically, the difference between the position of the convex portion 3 with respect to the blade root 4 in the state where the long material 1 is oriented in the horizontal direction and the position of the convex portion 3 with respect to the blade root 4 in the state where the long material 1 is oriented in the vertical direction may be determined. For example, the difference between the shape of the blade manufactured by grasping the convex portion 3 again with the position B as the re-grasping position and performing the subsequent steps and the desired shape of the blade may be obtained without considering the deformation due to the own weight of the long material 1, and the difference may be used as the deformation amount. By thus determining the amount of deformation due to the own weight of the long material 1 in advance, it is not necessary to determine the amount of deformation due to the own weight of the long material 1 in step S4 of determining the re-gripping position, and step S4 can be performed quickly.

In another embodiment, the step of determining the re-grip position may be to orient the long material 1 from which the grip of the convex portions 3 is released in the vertical direction, and determine the position of the convex portions 3 with respect to the blade root portion 4 as the re-grip position C in this state. By orienting the long material 1 in the vertical direction, the stress accompanying the deformation by the own weight of the long material 1 is released. Then, in a state where the grip of the convex portions 3 is released and the long material 1 is oriented in the vertical direction, both the strain caused by the first processing step and the stress accompanying the deformation caused by the own weight of the long material 1 are released, and therefore the position of the convex portions 3 with respect to the blade root portions 4 in this state becomes the re-grip position C. In this way, by orienting the long material 1 from which the gripping of the convex portions 3 is released in step S4 in the vertical direction, the re-gripping position C is determined for each long material 1 in consideration of the deformation due to its own weight, and the accuracy of the final finished state of the blade can be further improved.

As shown in fig. 2, after step S4 is completed, projection 3 is gripped again at determined grip position C (step S5). The re-gripping of the convex portion 3 at the re-gripping position C (see fig. 6) can be performed by selecting a shim plate 45 (see fig. 5) having an appropriate width and sandwiching it between the weight 43 and the pressing plate 41 so that the gripping position at the convex portion 3 becomes the re-gripping position C. When the displacement between the position a and the re-gripping position C is large, as shown in fig. 4, the platen 23 is rotated in the arrow E direction to slide the first receiving table 24 in the arrow F direction; the second holding portion 20 is moved to the re-holding position C by sliding the second receiving base 25 in the arrow G direction, whereby the convex portion 3 can be held at the re-holding position C.

After step S5 is completed, the second processing step of processing the free-form surface again on the long material 1 with the convex portions 3 and the blade root portions 4 gripped is performed in a state where the strain generated in the first processing step and the stress accompanying the deformation by the own weight of the long material 1 are released (step S6). As described above, when the convex portions 3 and the blade root portions 4 are gripped so that the chordwise direction L is oriented in the vertical direction at the blade tip end side of the blade to suppress deformation due to the weight of the blade, the variation in the re-gripping position of the convex portions 3 due to the individual difference of the blade is reduced, and therefore, the stress accompanying the deformation due to the weight of the long material 1 can be effectively released even when the convex portions are gripped again. In one embodiment, the first machining step may be rough machining of the free-form surface, and the second machining step may be finish machining of the free-form surface. In this case, after step S6 as finishing is completed, the blade is completed, and the method of the embodiment is ended.

In this way, by performing the second processing step in a state in which the strain of the long material 1 generated at the first processing step and the stress accompanying the deformation of the long material 1 due to the own weight of the long material 1 are released, the accuracy of the final finished state of the blade can be improved.

In another embodiment, as shown in fig. 7, after step S6 ends, steps S3 through S6 are repeated at least once (step S7). Even when the second machining step is performed a plurality of times, by performing steps S3 to S5 each time, the second machining step can be performed in a state where the strain generated when the free-form curved surface is machined and the stress due to the deformation by the self weight of the long material 1 are released, and therefore the accuracy of the final finished state of the blade can be improved.

In another embodiment, after step S6 in the flowchart of fig. 2 is completed, and after step S7 in the flowchart of fig. 7 is completed, the surface processing such as shot blasting may be performed on the long material 1 having a free-form surface processed thereon to improve mechanical properties. In this case, at step S6 in the flowchart of fig. 2 and at the last second processing step of step S7 in the flowchart of fig. 7, the amount of deformation of the long material 1 due to residual stress caused by the surface processing treatment or an additional reaction in the steps before and after the surface processing treatment may be predicted in advance, and the free-form surface may be processed in consideration of the predicted amount of deformation. The prediction of the deformation amount may be determined analytically or experimentally. The shot peening treatment includes glass shot peening and steel shot peening, and as the surface processing treatment, there may be mesh blasting, thermal spraying of a coating, inorganic coating, plating, heat treatment such as induction hardening and carburizing/nitriding, polishing, and the like.

In the second processing step before the surface processing treatment, the shape of the long material 1 to be processed in consideration of the predicted deformation amount is exemplified in fig. 8. In fig. 8, the horizontal direction is defined as an x-axis, the vertical direction is defined as a y-axis, and the directions of these axes are defined as an x-axis direction and a y-axis direction, respectively. The circumferential direction around an axis perpendicular to both the x axis and the y axis is defined as the θ direction. The axial direction perpendicular to both the x axis and the y axis, which is the center of the θ direction, is defined as the longitudinal direction of the long material 1.

Fig. 8 shows the final shape of the blade in the x-axis direction, the y-axis direction, and the θ direction, respectively, in a single-dot chain line. Δ x is a predicted deformation amount in the x-axis direction with respect to the final shape of the blade, Δ y is a predicted deformation amount in the y-axis direction with respect to the final shape of the blade, and Δ θ is a predicted deformation amount in the θ direction with respect to the final shape of the blade. In the second processing step, when the surface processing such as shot blasting is performed on the long material 1 processed into a shape including such a deformation amount, the long material 1 is deformed by Δ X toward the final shape in the X-axis direction, is deformed by Δ y toward the final shape in the y-axis direction, and is deformed by Δ θ toward the final shape in the θ direction due to the generated residual stress, thereby obtaining the blade of the final shape.

Therefore, in order to obtain a blade of a desired final shape, in the second processing step before the surface processing treatment, the long material 1 is processed into a shape corresponding to the final shape of the blade shifted by Δ x in the x-axis direction, by Δ y in the y-axis direction, and by Δ θ in the θ -direction.

Description of reference numerals:

1 strip of material

1a end region

1b another end region

2 shield

3 convex part

4 blade root

6 leading edge

7 trailing edge

10 first holding part

11 base part

12 pressing plate

13 supporting table

14 bolt

20 second holding part

21 base part

22 liner

23 bedplate

24 first receiving table

25 second receiving table

25a base part

25a1 front side

25b projection

25b1 front side

25b2 side

30 gap

31 frame body

31a through hole

32 top tightening screw

33 frame body

33a through hole

34 tightening screw

41 pressing plate

42 bolt

43 weight

44 bolt

45 backing plate

51 support part

52 backing plate

53 frame

53a through hole

54 bolt

61 rotating mechanism part

62 first sliding mechanism part

63 second slide mechanism part

64 gripping mechanism part

65 first sliding part

66 second sliding part

C holds the position again.