JP2011251401A - Machining method for machining workpiece surface - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for machining workpiece surface capable of smoothly machining a surface of a workpiece, without extending machining time, as well as, generating gouges.SOLUTION: In a method for machining workpiece surface having a three-dimensional shape by cutting the surface of the workpiece 26, a cutting tool 11, having a shaft section 111 and cutting section 112 is rotated in a prescribed direction around the shaft 111 as a center, and is subjected to reciprocating movement, along a path 27 where a plurality of approach paths 27a and return paths 27b arranged on a surface of a workpiece 26 are lined up alternately, and moved in a pick feed direction that is orthogonal to the approach paths 27a and the return paths 27b. Here, the shaft section 111 is tilted by a prescribed angle from the direction which is orthogonal to a surface of the workpiece 26 to the direction that the cutting section 112 located on a side of pick feed direction rotates, and additionally, the shaft section 111 is set so that the inclination from the direction lying along the in-surface direction of the surface of the workpiece 26 in the path 27 is less than ±45 degrees.

Description

  The present invention relates to a processing method for cutting a surface of a workpiece having a three-dimensional shape.

  When machining a workpiece having a three-dimensional shape such as a die, a ball end mill that includes a shaft portion and a blade portion provided on the tip side of the shaft portion and rotates in a predetermined direction around the shaft portion at the finishing stage. The cutting tool is used. The ball end mill has a spherical tip portion, and the blade portion is provided on a side surface of the spherical shape along the axial direction. The surface of the workpiece is cut by the blade that moves along with the rotation of the ball end mill by moving the ball end mill on the surface of the workpiece while rotating the ball end mill around the shaft. The

  Processing methods using a ball end mill are roughly classified into two types depending on the direction in which the blade is applied to the surface of the workpiece. Specifically, the cutting is performed by scooping the blade part against the workpiece surface from below and scooping, and cutting the blade part against the workpiece surface from above to press down. It is classified as down cut.

Here, when the surface of the workpiece is machined by up-cutting, the resistance applied to the blade portion is large, and the ball end mill is vibrated, which may cause stuffiness on the surface of the workpiece. When the work in which the squeak is generated is used, for example, as a mold for molding a resin product such as a front bumper of an automobile, unevenness due to squeeze may be transferred to the resin product.
On the other hand, when the surface of the workpiece is processed by down-cutting, the surface of the workpiece is less likely to cause murky, and the processing accuracy is good (see, for example, Patent Document 1).

  By the way, conventionally, in order to cut the surface of the workpiece without gaps, a plurality of paths arranged in a certain direction are set as paths for moving the ball end mill. As a mode of moving the ball end mill along the route, there are generally a one-way method in which the ball end mill is moved so as to write a river character in one direction and a two-way method in which the ball end mill is reciprocated so as to form a zigzag shape.

With the one-way method, the cutting conditions are unchanged and the direction in which the blade is applied is kept constant, so the surface of the workpiece can always be processed uniformly as a down cut, but the ball end mill can be moved from the end of each path to the start of the next path. The distance to be moved to is longer and more time is required, which increases the processing time.
On the other hand, in the two-way method, the processing time does not increase as in the one-way method, but the cutting condition is fluctuated and the direction in which the blade is applied is not kept constant, and the up-cut and the down-cut are repeated. The surface of the workpiece cannot be processed smoothly without being generated (see, for example, Patent Document 2).

JP 09-011020 A JP 2009-202258 A

  As described above, in the conventional processing method, the surface of the workpiece cannot be processed smoothly without extending the processing time and without causing stuffiness.

  Accordingly, an object of the present invention is to provide a method for processing a surface of a workpiece, which can smoothly process the surface of the workpiece without prolonging the processing time and without causing stuffiness.

  A method of processing a surface of a workpiece according to the present invention includes a cutting tool (e.g., a later-described shaft part 111) and a cutting tool (e.g., a later-described blade part 112) provided on a tip side of the shaft part (e.g. A plurality of forward paths (for example, an outbound path 27a described below) and a plurality of return paths provided on the surface of a work (for example, a work 26 described below) while rotating an end mill 11) described below in a predetermined direction around the shaft portion. (For example, a return path 27b described later) is moved in a pick-feed direction orthogonal to the forward path and the return path while reciprocating along a path (for example, a path 27 described later) alternately arranged, thereby moving the surface of the workpiece. In the method of processing the surface of a workpiece having a three-dimensional shape to be cut, a direction in which the blade portion positioned on the side of the pick feed direction rotates from the direction orthogonal to the surface of the workpiece. Inclining a predetermined angle (for example, an angle exceeding 10 degrees), and tilting the shaft portion from a direction along the path in the in-plane direction of the surface of the workpiece is less than ± 45 degrees. The present invention relates to a processing method for a surface of a workpiece.

  According to this invention, the cutting tool is inclined at a predetermined angle from the direction perpendicular to the surface of the workpiece to the direction in which the blade located on the side of the pick feed direction rotates, and the path in the in-plane direction of the surface of the workpiece of the cutting tool The inclination from the direction along the line was less than ± 45 degrees. Thereby, all the paths including the forward path and the return path provided on the surface of the workpiece can be processed by down-cutting. Therefore, the surface of the workpiece can be smoothly machined without extending the machining time and without causing stuffiness.

  In this case, the cutting tool is held so that it can be rotated about the shaft and translated in three-dimensional directions, and the cutting tool is vertically tilted at a predetermined angle from the vertical direction. It is preferable to hold it so that rotation around the axis is possible.

  According to the present invention, the cutting tool is held so as to be capable of parallel movement in each of the three-dimensional directions and rotational movement about the vertical axis in a state where the cutting tool is inclined at a predetermined angle with respect to the vertical axis. Accordingly, the workpiece surface can be machined by moving the cutting tool in the direction of the four axes, so that the accuracy of the workpiece surface machining can be further improved.

  In this case, when the inclination angle from the direction orthogonal to the surface of the workpiece in the direction in which the blade portion positioned on the side of the pick feed direction in the cutting tool rotates is 10 degrees or less, the cutting tool Is preferably rotated around the vertical axis and the direction of the path is switched.

When machining the surface of a workpiece having a three-dimensional shape with the shaft portion of the cutting tool inclined at a predetermined angle with respect to the vertical axis, depending on the angle of the surface of the workpiece, the direction from the direction orthogonal to the surface of the workpiece In some cases, the inclination in the direction in which the blade located on the side of the pick feed direction in the cutting tool rotates is 10 degrees or less.
Therefore, according to the present invention, when the inclination angle from the direction orthogonal to the surface of the workpiece in the direction in which the blade portion positioned on the side of the pick feed direction in the cutting tool rotates is 10 degrees or less, the cutting tool Is rotated around the vertical axis and the direction of the path is switched. As a result, the inclination of the cutting tool relative to the surface of the workpiece and the pick feed direction can be switched, so that the shaft portion of the cutting tool is moved to the surface of the workpiece in the direction in which the blade portion positioned on the side of the pick feed direction in the cutting tool rotates. The surface of the workpiece can be processed with the inclination angle from the orthogonal direction exceeding 10 degrees. Therefore, all the paths provided on the surface of the workpiece can be processed by down-cutting.

  According to the present invention, the cutting tool is tilted by a predetermined angle from the direction perpendicular to the surface of the workpiece to the direction in which the blade located on the side of the pick feed direction rotates, and along the path in the in-plane direction of the surface of the workpiece The inclination from the direction was less than ± 45 degrees. Thereby, all the paths including the forward path and the return path provided on the surface of the workpiece can be processed by down-cutting. Therefore, the surface of the workpiece can be smoothly machined without extending the machining time and without causing stuffiness.

It is a perspective view of the cutting device provided with the ball end mill used for the processing method of the present invention. It is a front view of a ball end mill. It is a perspective view explaining the path | route which moves a ball end mill. It is a figure explaining the direction and angle which incline a ball end mill, (A) is a top view of the surface of a workpiece | work, (B) is the figure seen in the direction of the arrow A shown to (A). It is a figure explaining becoming a down cut. It is a figure explaining the direction and angle which incline a ball end mill. It is a perspective view of a metal mold | die. It is a figure explaining the direction which inclines a ball end mill, and the path | route which moves a ball end mill, (A) is sectional drawing of the metal mold | die seen in the direction of the arrow B shown in FIG. 7, (B) is (A). It is the figure seen from the direction of the arrow C shown, (C) is the figure seen from the direction of the arrow D shown to (A), (D) is the figure which looked at the metal mold | die from the upper surface side, and is a pair of side surface It is a figure shown in the state which expanded.

Hereinafter, a processing method according to an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a perspective view of a cutting apparatus 1 used in the processing method of the present invention. FIG. 2 is a front view of a ball end mill (hereinafter abbreviated as an end mill) 11 as a cutting tool used by the cutting apparatus 1.

As shown in FIG. 1, a cutting apparatus 1 is an apparatus that uses an end mill 11 to cut a three-dimensional workpiece such as a die (hereinafter abbreviated as a workpiece).
The cutting apparatus 1 includes an end mill 11 that cuts a workpiece, a machine tool 12 that drives the end mill 11, and an NC device (Numerical Control unit) 13 that controls the machine tool 12.

  The machine tool 12 has a gate-type structure, and a pair of side walls 16 constituting the gate pillars on both sides of the machine tool 12 and a pair of sides extending between the side walls 16 extending in the Y-axis direction (horizontal direction). A main rail 17, a pair of traveling portions 18 that travel in the Y-axis direction along the main rail 17, and a pair that extends between the traveling portions 18 and extends in the X-axis direction (horizontal direction orthogonal to the Y-axis direction). , A table 20 that travels between the cross rails 19 in the X-axis direction, and a spindle head 21 that is attached to the lower part of the table 20.

  A workpiece (see FIG. 7) to be cut is fixed between the pair of side walls 16 by a fixing jig (not shown).

Both ends of the pair of main rails 17 are connected to both sides above each side wall 16.
The pair of traveling units 18 incorporates a drive mechanism (not shown) constituted by a servo motor or the like. The pair of traveling units 18 travel in conjunction with each other when the drive mechanism is driven under the control of the NC device 13.

Both ends of the pair of cross rails 19 are connected to both sides of each traveling unit 18.
The table 20 has a built-in drive mechanism (not shown) composed of a servo motor or the like. The table 20 travels by driving the drive mechanism under the control of the NC device 13.

The spindle head 21 can move up and down in the Z-axis direction (vertical direction) and can rotate around the Z-axis. The spindle head 21 holds a cutting tool such as the end mill 11 in a posture inclined at a predetermined angle (for example, 30 degrees) from the vertical direction. In the present embodiment, a case where the end mill 11 is held will be described as an example.
In the present embodiment, the end mill 11 held by the spindle head 21 is rotated clockwise (clockwise) about the shaft portion 111.

The spherically shaped portion 11a of the end mill 11 turns so as to draw a perfect circle in the XY plane as the spindle head 21 rotates around the Z axis.
The end mill 11 moves in the X-axis direction when the table 20 travels on the cross rail 19. The end mill 11 moves in the Y-axis direction when the traveling unit 18 travels on the main rail 17. The end mill 11 moves in the Z-axis direction when the spindle head 21 moves up and down. The end mill 11 changes the direction of inclination from the vertical direction when the spindle head 21 rotates around the Z axis.

  The rotational speed around the axis of the end mill 11 is appropriately set within a range predetermined for the machine tool 12 to be used.

As shown in FIG. 2, the end mill 11 includes a shaft portion 111 and a spherical portion 11 a having a blade portion 112 provided on the tip side of the shaft portion. The spherically shaped portion 11a is abutted against the work during the cutting process.
The blade 112 is provided on the side surface in the axial direction of the spherical portion.

Next, a processing method for cutting the surface of a workpiece using the cutting apparatus 1 will be described. In order to simplify the drawings and description, a plate-shaped two-dimensional workpiece 26 is used instead of the three-dimensional workpiece.
FIG. 3 is a perspective view of a two-dimensional workpiece (hereinafter abbreviated as a workpiece) 26 for explaining a path for moving the end mill 11. 4A and 4B are diagrams for explaining a direction and an angle for tilting the end mill 11, in which FIG. 4A is a top view, and FIG. 4B is a diagram viewed in the direction of an arrow A shown in FIG. FIG. 5 is a diagram for explaining that the cutting method by the end mill 11 is down cut. FIG. 6 is a diagram for explaining the direction and angle of tilting the end mill 11.

As shown in FIG. 3, the spherical portion 11 a of the end mill 11 is abutted against the surface 26 a of the workpiece 26.
Next, the end mill 11 is moved on the surface 26 a without a gap along the path 27 set on the surface 26 a of the workpiece 26 while rotating around the shaft portion 111.

The path 27 has a zigzag shape in which a plurality of forward paths 27a and a plurality of return paths 27b extending in a certain direction are alternately arranged.
A direction in which the plurality of forward paths 27a and the plurality of return paths 27b extend is referred to as a reciprocating direction. A direction that is orthogonal to the reciprocating direction and that moves the end mill 11 when turning back between the forward path 27a and the return path 27b is referred to as a pick feed direction (hereinafter referred to as a pick direction).

  When the end mill 11 is moved along the path 27, the surface 26a of the workpiece 26 is cut by the blade portion 112 positioned on the side of the end mill 11 in the pick direction.

As shown in FIG. 4A, the end mill 11 moving along the path 27 rotates in the clockwise direction around the shaft portion 111. The blade portion 112 located on the side of the end mill 11 in the pick direction rotates in the right direction when viewed in the direction of the arrow A.
As shown in FIG. 4B as viewed in the direction of arrow A, the end mill 11 is located on the side in the pick direction (the back side in the drawing) in the reciprocating direction from the direction orthogonal to the surface 26a of the workpiece 26. are inclined at a predetermined angle theta ₁ to the right edge portion 112 is a direction of rotation.

In other words, the direction in which the end mill 11 is inclined by the angle θ ₁ is set as the reciprocating direction of the end mill 11. Further, the end mill 11 is the side of the blade portion 112 that rotates in a direction which is inclined an angle theta ₁ is located (the back side of the drawing) is set as the pick direction.

By tilting the end mill 11 in the above-described direction by the above-mentioned angle, as shown in FIG. 5, the blade portion 112 of the end mill 11 has a down-cut that cuts to press down against the surface 26 a of the workpiece 26 from above. Realized.
In addition, it is preferable that angle (theta) ₁ is an angle exceeding 10 degree | times from a viewpoint which cuts the surface of a workpiece | work favorably with the blade part 112 of the end mill 11. FIG.

In the processing method of the present invention, as shown in FIG. 6, the end mill 11 is tilted in an in-plane direction of the surface 26 a of the workpiece 26 by an angle θ with an inclination from the reciprocating direction along the path 27 of less than ± 45 degrees. _It is necessary to control to be ₂ . By this angle theta ₂ and less than 45 degrees ±, perform the cutting with suitably cut down in all the paths 27 including forward 27a and backward 27b. This is because when the angle θ ₂ is decomposed into a pick feed direction component and a reciprocation direction component, the reciprocation direction component is larger than the pick feed direction component when the angle θ ₂ is less than ± 45 degrees. The reason is that it is maintained. In addition, the surface 26a of the workpiece | work 26 can be processed suitably, so that angle (theta) ₂ is near 0 degree | times.

Next, the case where the surface of the metal mold | die 31 which is a three-dimensional workpiece is cut is demonstrated.
FIG. 7 is a perspective view of the mold 31. 8 (A) to 8 (D) are diagrams for explaining a path for moving the end mill 11, and FIG. 8 (A) shows the mold 31 as viewed in the direction of arrow B shown in FIG. It is sectional drawing. FIG. 8B is a view of the mold 31 shown in FIG. 8A viewed in the direction of arrow C. The end mill 11 is rotated 90 degrees around the Z axis from the state shown in FIG. FIG. FIG. 8C is a view of the mold 31 shown in FIG. 8A viewed in the direction of arrow D. The end mill 11 is rotated 90 degrees around the Z axis from the state shown in FIG. FIG. FIG. 8D is a view of the mold 31 as viewed from the upper surface side, and is a view showing the pair of side surfaces 34 and 35 in an unfolded state.

As shown in FIG. 7, the mold 31 serving as a work has a symmetrical shape. The mold 31 has a molding surface 32 for molding a resin product.
The molding surface 32 includes a bottom surface 33, a pair of side surfaces 34, 35 standing upright with respect to the bottom surface 33, and a pair of inclined surfaces 36, 37 connected to the bottom surface 33 and the side surfaces 34, 35.

The bottom surface 33 is disposed substantially horizontally. Since the metal mold 31 has a symmetrical shape, the bottom surface 33 is divided into a left half first bottom surface 33a and a right half second bottom surface 33b.
Each of the pair of inclined surfaces 36 and 37 is inclined approximately 30 degrees with respect to the horizontal direction. The pair of side surfaces 34 and 35 are disposed substantially vertically.

  In the present embodiment, a case where the path for moving the end mill 11 is set from the side surface 34 in the order of the inclined surface 36, the first bottom surface 33a, the second bottom surface 33b, the inclined surface 37, and the side surface 35 will be described.

First, as shown in FIG. 8A, when the end mill 11 held by the spindle head 21 in a posture inclined by 30 degrees from the vertical direction is abutted against the side surface 34, the end mill 11 is orthogonal to the side surface 34. approximately 60 degrees to the side of the vertically upward direction from the direction, i.e., inclined angle theta ₁ of greater than 10 degrees.

As shown in FIG. 8D, since the end mill 11 is tilted toward the vertical direction on the side surface 34, the vertical direction is set as the reciprocating direction of the end mill 11 (see FIG. 4B). In addition, since the end mill 11 is tilted vertically upward on the side surface 34, the front side of the mold 31 on which the blade portion 112 that rotates in the vertically upward direction is located is set as the pick direction ( (See FIG. 5).
In this way, the end mill 11 is moved along the path set on the side surface 34. In this state, the inclination of the end mill 11 from the direction along the in-plane path of the side surface 34 is 0 degrees, that is, less than ± 45 degrees.

  Next, as shown in FIG. 8A, if the end mill 11 is abutted against the inclined surface 36 while maintaining the posture in the case of the side surface 34, the end mill 11 is substantially orthogonal to the inclined surface 36 (end mill 11). The angle of inclination from the direction orthogonal to the inclined surface 36 in the direction in which the blade portion 112 positioned on the side of the pick feed direction in FIG.

Therefore, the spindle head 21 is rotated by −90 degrees around the Z axis to change the inclination of the end mill 11 from the direction orthogonal to the inclined surface 36 and to switch the direction of the path by 90 degrees. Then, as shown in FIG. 8 (B), the end mill 11 is inclined approximately 30 degrees, that is, an angle θ ₁ exceeding 10 degrees from the direction orthogonal to the inclined surface 36 toward the front side of the mold 31.

Further, as shown in FIG. 8D, since the end mill 11 is tilted toward the front side of the mold 31 on the inclined surface 36, the front side and the back side of the mold 31 are set as the reciprocating direction of the end mill 11. (See FIG. 4B). Further, the right side of the mold 31, which is the side on which the blade portion 112 that rotates toward the front side of the mold 31 is located, is set as the pick direction (see FIG. 5).
In this way, the end mill 11 is moved along the path set on the inclined surface 36. In this state, the inclination of the end mill 11 from the direction along the in-plane path of the inclined surface 36 is 0 degree, that is, less than ± 45 degrees.

Next, as shown in FIG. 8A, at the first bottom surface 33 a, the spindle head 21 is rotated 90 degrees around the Z axis so that the attitude of the end mill 11 is the same as that of the side surface 34. End mill 11 is approximately 30 degrees to the right of the mold 31 from the direction perpendicular to the first bottom surface 33a, i.e., inclined angle theta ₁ of greater than 10 degrees.

As shown in FIG. 8D, since the end mill 11 is inclined to the right side of the mold 31 at the first bottom surface 33a, the left-right direction of the mold 31 is set as the reciprocating direction of the end mill 11 (FIG. 4B )reference). Further, the back side of the mold 31, which is the side on which the blade 112 rotating in the right direction of the mold 31 is located, is set as the pick direction (see FIG. 5).
In this way, the end mill 11 is moved along the path set on the first bottom surface 33a. In this state, the inclination of the end mill 11 from the direction along the in-plane path of the first bottom surface 33a is 0 degrees, that is, less than ± 45 degrees.

Next, as shown in FIG. 8A, at the second bottom surface 33b, the spindle head 21 is rotated 180 degrees around the Z axis, so that the attitude of the end mill 11 is reversed from the case of the first bottom surface 33a. End mill 11 is approximately 30 degrees to the left of the die 31 from a direction perpendicular to the second bottom surface 33b, i.e., inclined angle theta ₁ of greater than 10 degrees.

As shown in FIG. 8D, since the end mill 11 is inclined to the left side of the mold 31 at the second bottom surface 33b, the left-right direction of the mold 31 is set as the reciprocating direction of the end mill 11 (FIG. 4B )reference). Further, the front side of the mold 31, which is the side on which the blade portion 112 that rotates in the left direction of the mold 31 is located, is set as the pick direction (see FIG. 5).
Thus, the end mill 11 is moved along the path set on the second bottom surface 33b. In this state, the inclination of the end mill 11 from the direction along the in-plane path of the second bottom surface 33b is 0 degree, that is, less than ± 45 degrees.

  Next, as shown in FIG. 8A, if the end mill 11 is abutted against the inclined surface 37 while maintaining the posture in the case of the second bottom surface 33b, the end mill 11 is substantially orthogonal to the inclined surface 37 (end mill). 11, the inclination angle from the direction orthogonal to the inclined surface 37 in the direction in which the blade 112 positioned on the side of the pick feed direction in FIG.

Therefore, the spindle head 21 is rotated 90 degrees around the Z axis to change the inclination of the end mill 11 from the direction orthogonal to the inclined surface 37 and to change the direction of the path by 90 degrees. Then, as shown in FIG. 8 (C), end mill 11 is approximately 30 degrees to the front side of the die 31 from a direction perpendicular to the inclined surface 37, i.e., inclined angle theta ₁ of greater than 10 degrees.

Further, as shown in FIG. 8D, since the end mill 11 is tilted toward the front side of the mold 31 on the inclined surface 37, the front side and the back side of the mold 31 are set as the reciprocating direction of the end mill 11. (See FIG. 4B). Further, the right side of the mold 31, which is the side on which the blade 112 moving in the direction toward the front side of the mold 31 is located, is set as the pick direction (see FIG. 5).
In this way, the end mill 11 is moved along the path set on the inclined surface 37. In this state, the inclination of the end mill 11 from the direction along the in-plane path of the inclined surface 37 is 0 degree, that is, less than ± 45 degrees.

Next, as shown in FIG. 8A, on the side surface 35, the spindle head 21 is rotated by -90 degrees around the Z axis so that the attitude of the end mill 11 is the same as that of the second bottom surface 33b. End mill 11 is approximately 60 degrees on the side of the vertically upward direction from the direction perpendicular to the side surface 35, i.e., inclined angle theta ₁ of greater than 10 degrees.

As shown in FIG. 8D, since the end mill 11 is tilted in the vertical direction on the side surface 35, the vertical direction is set as the reciprocating direction of the end mill 11 (see FIG. 4B). Further, since the end mill 11 is inclined vertically upward on the side surface 35, the back side of the mold 31 on which the blade portion 112 moving in the vertically upward direction is located is set as the pick direction (FIG. 5). reference).
In this way, the end mill 11 is moved along the path set on the side surface 35. In this state, the inclination of the end mill 11 from the direction along the in-plane path of the side surface 35 is 0 degree, that is, less than ± 45 degrees.

According to this embodiment, there are the following effects.
The (1) end mill 11, from a direction perpendicular to the surface 26a of the workpiece 26, tilted angle theta ₁ exceeds 10 degrees in the direction the blade unit 112 which is located on the side of the pick direction is moved, and the surface 26a of the workpiece 26 The inclination from the direction along the path 27 in the in-plane direction was less than ± 45 degrees. Thereby, all the paths 27 including the forward path 27a and the return path 27b provided on the surface 26a of the workpiece 26 can be processed by down-cutting. Therefore, the surface 26a of the workpiece 26 can be smoothly machined without extending the machining time and without causing stuffiness.

  (2) With the end mill 11 tilted by 30 degrees with respect to the Z axis (vertical axis), the end mill 11 is held so as to be capable of parallel movement in each of the three-dimensional directions and rotational movement about the Z axis (vertical axis). It was. Therefore, the end mill 11 can be moved in the four-axis directions to process the molding surface 32 (the bottom surface 33, the pair of side surfaces 34, 35 and the pair of inclined surfaces 36, 37) of the mold 31 having a three-dimensional shape. The processing accuracy of the molding surface 32 of the mold 31 can be further improved.

(3) The molding surface 32 (the bottom surface 33, the pair of side surfaces 34, 35, and the like) of the mold 31 having a three-dimensional shape while maintaining the shaft portion 111 of the end mill 11 in a posture inclined by 30 degrees with respect to the Z axis (vertical axis). When machining the pair of inclined surfaces 36 and 37), depending on the angle of the molding surface 32, the direction in which the blade 112 positioned on the side of the pick feed direction in the end mill 11 from the direction orthogonal to the surface of the molding surface 32 rotates. The inclination to may be 10 degrees or less.
Therefore, when the inclination angle from the direction orthogonal to the surface of the molding surface 32 in the direction in which the blade 112 positioned on the side of the pick feed direction in the end mill 11 rotates is 10 degrees or less, the end mill 11 is moved to the Z axis. The direction of the path 27 is switched while rotating around (vertical axis). As a result, the shaft portion 111 of the end mill 11 is rotated by, for example, 90 degrees about the Z axis (vertical axis), thereby forming the blade portion 112 positioned on the side of the pick feed direction in the end mill 11 in the rotating direction. The molding surface 32 can be processed in a state where the inclination angle from the direction orthogonal to the surface of the surface 32 is set to an angle exceeding 10 degrees. Therefore, all the paths 27 provided on the molding surface 32 can be processed by down-cutting.

  (4) By rotating the end mill 11 about the Z axis (vertical axis) by the spindle head 21, the inclination of the end mill 11 with respect to the workpiece is changed, and before and after the end mill 11 is rotated about the Z axis (vertical axis). To change the direction of the route 27. Therefore, the molding surface 32 of the mold 31 having a three-dimensional shape can be processed with a simple configuration.

It should be noted that the present invention is not limited to the above-described embodiment, but includes modifications and improvements as long as the object of the present invention can be achieved.
For example, in the present embodiment, the spindle head 21 holds the end mill 11 in a posture tilted by 30 degrees from the vertical direction, but the tilt angle is not limited thereto. For example, the end mill may be inclined at an angle of more than 10 degrees from the vertical direction and less than 80 degrees from the vertical direction.

  Moreover, in this embodiment, although the inclination from the direction along the path | route in the in-plane direction of the molding surface 32 of the metal mold | die 31 in the end mill 11 was always performed as 0 degree | times, it processed, it is not restricted to this. That is, the inclination from the direction along the in-plane direction path of the molding surface of the mold in the end mill may be less than ± 45 degrees.

  Further, in the present embodiment, when the inclination angle from the direction orthogonal to the surface of the molding surface 32 in the direction in which the blade 112 located on the side of the pick feed direction in the end mill 11 rotates is 10 degrees or less, Although the end mill 11 is rotated 90 degrees around the Z axis (vertical axis), the present invention is not limited to this. That is, the rotation angle around the Z axis (vertical axis) of the end mill may be less than 90 degrees or more than 90 degrees. That is, the inclination from the direction along the path in the in-plane direction of the molding surface of the mold in the rotated end mill may be less than ± 45 degrees.

  Moreover, in this embodiment, although the ball end mill 11 was used as a cutting tool, it is not restricted to this. That is, a radius end mill may be used as a cutting tool.

11 Ball end mill (cutting tool)
111 Shaft part 112 Blade part 26 Work 26a Surface 27 Path 27a Outward path 27b Return path 31 Mold (Workpiece)

Claims (3)

A plurality of forward paths and a plurality of return paths provided alternately on the surface of the workpiece are alternately rotated while rotating a cutting tool including a shaft portion and a blade portion provided on the tip side of the shaft portion in a predetermined direction around the shaft portion. In the processing method of the surface of the workpiece having a three-dimensional shape for cutting the surface of the workpiece by moving in the pick-feed direction orthogonal to the forward path and the backward path while reciprocating along the aligned path,
The shaft portion is inclined by a predetermined angle from a direction perpendicular to the surface of the workpiece to a direction in which the blade portion located on the side of the pick feed direction rotates, and the shaft portion is in-plane with the surface of the workpiece. A method of processing a surface of a workpiece, wherein an inclination of the direction from the direction along the path is less than ± 45 degrees.   The cutting tool is held so that it can be rotated around the shaft and translated in three-dimensional directions, and the cutting tool is tilted by a predetermined angle from the vertical direction around the vertical axis. 2. The method for processing a surface of a workpiece according to claim 1, wherein the workpiece is held so as to be rotatable.   When the inclination angle from the direction perpendicular to the surface of the workpiece in the direction in which the blade portion positioned on the side of the pick feed direction in the cutting tool rotates is 10 degrees or less, the cutting tool is moved to the vertical axis. The method of processing a surface of a workpiece according to claim 2, wherein the direction of the path is switched while rotating around.

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