JP7538586B2 - Processing tools, machine tools and processing methods - Google Patents

Description

The present invention relates to a machining tool, a machine tool, and a machining method for performing spline machining or serration machining on a workpiece.

A machining tool is provided that can machine square holes with a bottom at high precision using a general-purpose machine tool such as a drill press or lathe (see Patent Document 1). The machining tool includes, for example, a holder, a blade support shaft, and a square hole machining blade, and is structured so that the blade support shaft is rotatably held by the holder with the central axis of the shaft itself inclined by about 2° relative to the central axis of the holder so that the center of the tip surface of the square hole machining blade attached to the blade support shaft is located on the central axis of the holder.

The above-mentioned machining tool is held on the tool post of a general-purpose machine tool, and when machining a bottomed square hole in a workpiece, for example, the tool post holding the machining tool is moved along the central axis of the rotating headstock toward the headstock holding the workpiece. When the tool post moves toward the headstock, the machining tool held on the tool post is pressed against the peripheral portion of the pilot hole provided in the workpiece, the square hole machining blade rotates and oscillates around the axis of the held shaft of the holder, with the center of the tip surface of the square hole machining blade, i.e., the intersection of the central axis of the blade support shaft and the central axis of the holder as the swing center. At this time, the pressing position between the peripheral edge of the tip surface of the square hole machining blade, which is inclined to the central axis of the holder, and the workpiece rolls and moves in the circumferential direction, so that the peripheral portion of the tip peripheral portion of the square hole machining blade, which is the most advanced position in the feed direction of the machining tool, advances in a spiral shape toward the depth direction of the pilot hole provided in the workpiece. As a result, the periphery of the pilot hole in the workpiece is sheared along the contour shape of the tip surface of the square hole drilling blade, and a square hole with a bottom is drilled in the workpiece.

It has also been proposed to machine the outer periphery of the workpiece using a general-purpose machine tool (see Patent Document 2). In this case, a protrusion on the mandrel of the lathe is connected to a rod extending outward from the outer periphery of the tool carrier shaft of the sleeve, and when the sleeve is moved to the mandrel, the tool carrier shaft of the sleeve is rotated in accordance with the rotation of the mandrel, causing the tool attached to the tool carrier shaft to perform a rotary oscillating motion. As a result, the periphery of the outer periphery of the workpiece is sheared along the contour shape of the inclined tip surface of the tool, and the cross-sectional shape of the outer periphery of the workpiece is machined into, for example, a square shape.

Japanese Patent Application Publication No. 08-294809 Japanese Patent Application Publication No. 50-31482

For example, as disclosed in Patent Document 1, the operation of pressing the cutting blade of the processing tool against the workpiece while rotating the workpiece about the central axis of the workpiece applies a very large load to the cutting edge of the cutting blade of the processing tool. As shown in FIG. 16, the cutting blade 201 has, for example, a plurality of teeth 202 formed at a predetermined angular interval on the outer circumferential surface. These teeth 202 extend along the central axis C8 of the cutting blade 201. Therefore, when the cutting blade 201 is moved along the central axis C9 of the workpiece W0 (see FIG. 17) and the teeth 202 of the cutting blade 201 are pressed against the workpiece W0, the ends of the teeth 202 on the cutting edge surface 203 side are damaged by the impact when pressed against the workpiece W0, and tooth chipping 204 occurs. In FIG. 16, the state of the teeth 202 of the cutting blade 201 before machining the workpiece W0 is shown by dotted lines, and the state of the teeth 202 of the cutting blade 201 after machining the workpiece W0 is shown by solid lines.

On the other hand, the workpiece W0 is cut to match the outer peripheral shape of the multiple teeth 202 of the cutting blade 201, forming a spline-shaped hole (hereinafter, serrated hole) 206 having multiple teeth 205 on the inner peripheral surface. However, if multiple teeth of the cutting blade 201 are missing, not only will tooth chipping (sagging) 210 occur at the entrance of the serrated hole 206 formed in the workpiece W0, but the tooth trace of the multiple teeth 205 formed in the serrated hole 206 will be bent (reference numeral 211 in FIG. 17(b)), or the teeth formed in the serrated hole 206 will be cut more than necessary, resulting in problems such as the serrated hole 206 not being machined with high precision.

In addition, in the processing method disclosed in Patent Document 2, the tool rotates together with the workpiece, so that the impact acting on the cutting edge of the tool when the tool is pressed against the workpiece is suppressed. However, in the axial direction of the tool carrier shaft, the position (point of action) where the protrusion on the mandrel holding the workpiece rotates the rod protruding from the tool carrier shaft is shifted from the position where the cutting edge of the tool processes the workpiece. Therefore, in a plane perpendicular to the central axis of the mandrel, the center of rotation of the mandrel does not coincide with the center of rotation of the above-mentioned point of action when the tool carrier shaft is rotated. As described above, since the protrusion on the mandrel holding the workpiece rotates the rod protruding from the tool carrier shaft, the rotation position of the protrusion on the mandrel coincides with the rotation position of the rod protruding from the tool carrier shaft in a plane perpendicular to the central axis of the mandrel. For this reason, the rotation angle (rotation speed) of the rod, i.e., the rotation angle (rotation speed) of the tool carrier shaft, changes periodically relative to the rotation angle (rotation speed) of the mandrel projection. As a result, when forming a spline-shaped hole in the workpiece, machining defects occur, such as excessive cutting at the start position of machining of the workpiece, or cutting further than the tip shape of the cutting tool. This causes problems such as excessive load being placed on the cutting tool cutting edge and making it difficult to accurately machine a spline-shaped hole in the workpiece.

The present invention was made in consideration of these problems, and its purpose is to provide a technology for machining workpieces with high precision using general-purpose machine tools.

In order to solve such problems, one aspect of the machining tool of the present invention comprises a machining blade for machining a workpiece attached to a fixture, a holding shaft for holding the machining blade at one end in the direction of its central axis, a holder for holding the holding shaft so that the holding shaft can rotate about the central axis of the holding shaft, and a first jig provided on the holding shaft, the holder holds the holding shaft with the central axis of the holding shaft inclined relative to its own central axis, and the machining blade is disposed at the tip of the machining blade when the holding shaft is held by the holder. The first jig is arranged so that the center of rotation on the plane coincides with the intersection of the central axis of the holder and the central axis of the holding shaft, and when the fixing tool and the holder are brought close to each other while rotating either the fixing tool or the holder about its own central axis, the first jig abuts against the second jig provided on the fixing tool on a plane that is perpendicular to the central axis of the holding shaft and includes the intersection, thereby aligning the rotational position of the workpiece and the rotational position of the cutting blade in the rotational direction of either the rotating fixing tool or the holder.

In addition, one aspect of the machine tool of the present invention includes a fixture to which a workpiece is attached, a machining tool for machining the workpiece, and a holder for holding the machining tool, the machining tool including a machining blade for machining the workpiece by being pressed against the workpiece, a holding shaft for holding the machining blade at one end in the direction of its own central axis, a holder for holding the holding shaft rotatably about the central axis of the holding shaft, and a first jig provided on the holding shaft, the fixture including a second jig that comes into contact with the first jig when machining the workpiece, and the holder for holding the holding shaft with the central axis of the holding shaft tilted relative to its own central axis. The cutting blade is arranged so that when the holding shaft is held by the holder, the center of rotation at the tip surface of the cutting blade coincides with the intersection of the central axis of the holder and the central axis of the holding shaft, and when the fixing tool or the holder is brought close to each other while rotating either the fixing tool or the holder about its own central axis, the first jig abuts against a second jig provided on the fixing tool on a plane that is perpendicular to the central axis of the holding shaft and includes the intersection, thereby aligning the rotational position of the workpiece and the rotational position of the cutting blade in the rotational direction of either the rotating fixing tool or the holder.

In addition, one aspect of the processing method of the present invention is a method of processing a workpiece attached to a fixture using a processing tool held by a holding fixture, the processing tool having a processing blade that processes the workpiece by being pressed against the workpiece, a holding shaft that holds the processing blade at one end side in the direction of its central axis, a holder that holds the holding shaft so that the holding shaft can rotate about the central axis of the holding shaft, and a first jig provided on the holding shaft, the fixing fixture having a second jig that comes into contact with the first jig when processing the workpiece, the holder holding the holding shaft with the central axis of the holding shaft inclined with respect to its own central axis, the processing blade being supported by the holding shaft being supported by the holding shaft. The method includes the steps of: rotating either the fixture or the holder about its own central axis when the fixture is held such that the center of rotation at the tip surface of the cutting blade coincides with the intersection between the central axis of the holder and the central axis of the holding shaft; bringing the fixture and the holder close together and abutting against a second jig provided on the fixture on a plane that is perpendicular to the central axis of the holding shaft and includes the intersection, thereby aligning the rotational position of the workpiece and the rotational position of the cutting blade in the rotational direction of either the rotating fixture or the holder; and pressing the cutting blade of the processing tool against the workpiece to process the workpiece.

This invention allows workpieces to be machined with high precision.

FIG. 1 is an external view showing an overview of a machine tool. FIG. 2 is a functional block diagram showing an electrical configuration of the machine tool shown in FIG. 1 . FIG. 2 is a perspective view showing an example of a configuration in the vicinity of a chuck of a spindle. FIG. 1 is a front view of the chuck when a side surface of a spindle-side jig is disposed at a distance from a plane including the rotation center of the chuck. FIG. 2 is a front view of the chuck when a side surface of a spindle-side jig is placed on a plane including the rotation center of the chuck. FIG. 2 is a plan view showing an example of a machining tool. FIG. 2 is an exploded plan view showing an example of a configuration in the vicinity of a blade body supporting shaft and a processing blade body. FIG. 2 is an exploded perspective view showing an example of a configuration of a rotation assist mechanism. FIG. 2A is a diagram showing a tool side jig having a plate-shaped contact portion, as viewed from the front side of the spindle, and FIG. 2B is a diagram showing the tool side jig, as viewed from the side side of the spindle. 1A is a diagram showing the positional relationship between the gripping jaws of the chuck and the abutment portion of the tool side jig of the rotation assist mechanism when processing of the workpiece begins, as viewed from the front side of the spindle, and FIG. 1B is a diagram showing the state of FIG. 1A, as viewed from the top side of the spindle. 1A is a diagram showing the positional relationship between the gripping jaws of the chuck and the abutment portion of the tool-side jig of the rotation assist mechanism when the abutment portion of the tool-side jig has moved onto the rotation trajectory of the spindle-side jig fixed to the gripping jaws of the chuck, as viewed from the front side of the spindle; and FIG. 1B is a diagram showing the state of FIG. 1A as viewed from the top side of the spindle. 1A is a diagram showing the positional relationship between the gripping jaws of the chuck and the abutment portion of the tool side jig of the rotation assist mechanism when the cutting edge surface of the machining blade is pressed against the workpiece, as viewed from the front side of the spindle; FIG. 1B is a diagram showing the state of FIG. 1A, as viewed from the top side of the spindle; FIG. 4 is a perspective view showing a state of a spline-shaped hole formed in a workpiece. 1A is a diagram showing the positional relationship between the gripping jaws of the chuck and the abutment portion of the tool-side jig of the rotation assist mechanism when the tip of the abutment portion of the tool-side jig abuts against a pin provided on the gripping jaws, as viewed from the front side of the spindle; FIG. 1B is a diagram showing the state of FIG. 1A, as viewed from the top side of the spindle. FIG. 11 is a perspective view showing an example in which spindle-side jigs are respectively arranged between gripping jaws provided on a chuck and the arranged spindle-side jigs are respectively fixed to the chuck. FIG. 13 is a perspective view showing a state in which a plurality of blades of a processing blade are broken when a processing method according to the prior art is adopted. FIG. 1 is a perspective view showing a state of a spline-shaped hole formed in a workpiece when a machining method according to the prior art is adopted.

The following describes an embodiment of the present invention with reference to the drawings. Fig. 1 is an external view showing an overview of a machine tool 10. Fig. 2 is a functional block diagram showing the electrical configuration of the machine tool 10. Fig. 3 is a perspective view showing an example of the configuration near the spindle 11.

As shown in Figures 1 to 3, the machine tool 10 is, for example, a numerically controlled (NC) lathe, and includes, for example, a spindle 11, a tool rest 12, and an operation panel 13. The spindle 11 holds a workpiece W and rotates about a central axis C1 (see Figure 3). The driving force for rotating the spindle 11 about the central axis C1 is provided by a spindle rotation drive unit 15. Although not shown, the spindle rotation drive unit 15 includes, for example, a servo amplifier, a servo motor, and an encoder.

The spindle 11 is equipped with a chuck 17 having multiple gripping jaws 16. The chuck 17 corresponds to the fixture described in the claims. In the embodiment, the chuck 17 corresponds to the fixture described in the claims, but the fixture described in the claims can refer to, for example, not only the part (chuck 17) that grips the workpiece W, but also the entire device having that part. The multiple gripping jaws 16 are arranged at regular angular intervals around the periphery of the front surface of the chuck 17. Below, a case where three gripping jaws 16 are provided will be described, and the three gripping jaws 16 will be referred to as gripping jaws 16a, gripping jaws 16b, and gripping jaws 16c.

The gripping jaws 16a, 16b, and 16c are each moved along the radial direction of the spindle 11 by the chuck driving unit 18. For example, when attaching the workpiece W to the chuck 17, the three gripping jaws 16a, 16b, and 16c move simultaneously toward the center of rotation of the chuck (direction A in FIG. 3). On the other hand, when removing the workpiece W from the chuck 17, the three gripping jaws 16a, 16b, and 16c move simultaneously from the center of rotation of the chuck 17 toward the outer periphery of the chuck 17 (direction B in FIG. 3). Although not shown, the chuck driving unit 18 includes, for example, a servo amplifier, a servo motor, and an encoder.

Of the three gripping jaws 16a, 16b, and 16c, the spindle-side jig 21 is fixed to the gripping jaw 16a. When the spindle 11 rotates, the spindle-side jig 21 abuts against the abutment portion 85 of the tool-side jig 62 of the machining tool 40 (described later) to rotate the blade support shaft 42 of the machining tool 40.

The spindle-side jig 21 is, for example, a T-shaped member having an attachment piece 21a extending along the upper surface 22 of the gripping jaws 16a and a pressing piece 21b perpendicular to the attachment piece 21a. The spindle-side jig 21 corresponds to the second jig described in the claims.

When the tool rest 12 is moved toward the rotating spindle 11, the pressing piece 21b presses the abutment portion 85 of the tool side jig 62 described later, rotating the blade support shaft 42 and the machining blade 43 fixed to the blade support shaft 42. The tip of the pressing piece 21b is located closer to the tool rest 12 than the end surface 91 of the workpiece W held by the gripping claws 16, and with the pressing piece 21b pressing the abutment portion 85 of the tool side jig 62 of the machining tool 40, the machining blade 43 of the machining tool 40 described later processes the workpiece W.

The pressing piece 21b is provided with a buffer pin 27. The pin 27 has a hemispherical tip. The pin 27 is held in a protruding state from the upper surface 23 of the pressing piece 21b by a coil spring (not shown) stored inside the pressing piece 21b. When the tip of the abutment portion 85 of the tool side jig 62 of the machining tool 40 comes into contact with the tip of the pin 27 during the process of the tool rest 12 moving toward the rotating spindle 11, the pin 27 is pushed into the inside of the pressing piece 21b, preventing the tip of the abutment portion 85 of the tool side jig 62 from colliding with the upper surface 23 of the pressing piece 21b. In the process of the pin 27 being pressed retracting into the pressing piece 21b, the engagement between the contact portion 85 of the tool side jig 62 and the pin 27 is released, and when the spindle side jig 21 rotates again to the position of the contact portion 85 of the tool side jig 62, the first contact portion 85a or the second contact portion 85b of the contact portion 85 of the tool side jig 62 abuts against the pin 27 or the side surface 24 of the pressing piece 21b. The second contact portion 85b abuts against the side surface 24 of the pressing piece 21b before the machining blade 43 comes into contact with the workpiece W, so that the rotation of the workpiece W and the rotation of the machining blade 43 are synchronized.

As shown in FIG. 4, when the spindle-side jig 21 is fixed to the gripping jaws 16a of the chuck 17, the side surface 24 of the spindle-side jig 21 is parallel to a plane PL1 including the central axis C1 of the spindle 11, and is disposed at a distance H from the plane PL1. At this time, the distance H is the distance from the abutment point P2 where the side surface 24 of the spindle-side jig 21 abuts against the second abutment portion 85b of the tool-side jig 62 during machining of the workpiece W to the center P5 of the second abutment portion 85b of the tool-side jig 62, which has a circular cross section, i.e., the same as the radius R of the second abutment portion 85b of the tool-side jig 62.

4, the side surface 24 of the spindle side jig 21 is arranged with a distance H from the plane PL1, and the distance H is the same as the radius R of the second abutment portion 85b. However, if the side surface 24 of the spindle side jig 21 can abut against the second abutment portion 85b, the distance H does not need to be the same as the radius R of the second abutment portion 85b. For example, as shown in FIG. 5, the spindle side jig 21 may be fixed to the gripping jaws 16a of the chuck 17 so that the side surface 24 of the spindle side jig 21 is included in a plane PL1' including the central axis C1 of the spindle 11. Although not shown, in this case, the distance H is H = 0. Furthermore, since it is possible to adopt a shape other than a circle as the cross-sectional shape of the second contact portion 85b, the above-mentioned distance H only needs to be a distance that allows the side surface 24 of the spindle-side jig 21 and the second contact portion 85b to come into contact with each other, and the distance H can be set appropriately.

Returning to FIG. 3 from FIG. 1, the tool rest 12 is disposed at a position spaced a predetermined distance from the chuck 17 of the spindle 11, and is moved in either the x direction or the -x direction, or in either the z direction or the -z direction, by the movement device 31. In addition, the tool holder 35 provided on the tool rest 12 is rotated around a straight line extending in the z direction by the swivel drive unit 32, as described below.

The moving device 31 has an X-axis drive unit 33 that moves the tool rest 12 in the cutting direction (x direction or -x direction) of the workpiece W by the machining tool 40 described below, and a Z-axis drive unit 34 that moves the tool rest 12 in a feed direction (z direction or -z direction) perpendicular to the cutting direction. Although not shown, the X-axis drive unit 33 and the Z-axis drive unit 34 each include, for example, a servo amplifier, a servo motor, and an encoder. The relative positions of the spindle 11 and the tool rest 12 change when the tool rest 12 is moved by the X-axis drive unit 33 and the Z-axis drive unit 34 of the moving device 31.

The relative positions of the spindle 11 and the tool rest 12 are changed by moving the tool rest 12 using the X-axis drive unit 33 and the Z-axis drive unit 34 of the moving device 31. However, it is also possible to change the relative positions of the spindle 11 and the tool rest 12 by moving the spindle 11 instead of the tool rest 12, or by moving the spindle 11 and the tool rest 12 separately.

The tool rest 12 has a plurality of tool holding sections 35. Each tool holding section 35 holds a machining tool 40, which will be described later. The tool rest 12 rotates the plurality of tool holding sections 35 as a unit around a horizontal axis by the swivel drive section 32, and moves the machining tool 40 to be used when machining the workpiece W, among the machining tools 40 held by each of the tool holding sections 35, to a predetermined position. Although not shown in the figure, the swivel drive section 32 includes, for example, a servo amplifier, a servo motor, and an encoder.

The control device 36 includes a CPU, ROM, and RAM (not shown), and controls the operation of each drive unit based on the machining program stored in the ROM and the data output from the encoder of each drive unit described above.

The operation panel 13 is provided for the operator to operate the machine tool 10, and has, for example, a display panel 37 and operation buttons 38. The operation panel 13 may be a touch panel that allows input operations and selection operations by touching the screen.

Next, the machining tool 40 used in the above-mentioned machine tool 10 will be described. The machining tool 40 is used, for example, when machining a spline-shaped hole in the workpiece W. As shown in FIG. 5, the machining tool 40 has a holder 41, a blade support shaft 42, a machining blade 43, and a rotation assist mechanism 44. The holder 41 has a holding shaft 46 and a bearing 47. When the machining tool 40 is fixed to the tool rest 12 of the machine tool 10, the holding shaft 46 is fixed and held by the tool holding portion 35 of the tool rest 12. The bearing 47 has a storage recess 47a, and holds the blade support shaft 42 in the storage recess 47a. Here, the blade support shaft 42 corresponds to the holding shaft described in the claims.

6 and 7, the blade support shaft 42 is stored and held in the storage recess 47a of the bearing portion 47 of the holder 41 with its own central axis C2 intersecting with the central axis C3 of the holder 41 at a predetermined distance outside the end face of the bearing portion 47 opposite the holding shaft portion 46, and inclined at an intersection angle θ1. The point where the central axis C2 of the blade support shaft 42 and the central axis C3 of the holder 41 intersect coincides with the rotation center P3 of the cutting edge surface 43a of the processing blade 43, which will be described later. As an example, the intersection angle θ1 is θ1 = 2.1°. The intersection angle θ1 is preferably in the range of θ1 = 1 to 2.3°, but may be an angle slightly outside that range. When the blade support shaft 42 is stored in the storage recess 47a provided on the end face of the bearing portion 47 of the holder 41 opposite the holding shaft portion 46, the blade support shaft 42 is supported by multiple rolling bearings (not shown) and can rotate (spin) around its own central axis C2. The outer ring of the rolling bearing is included in the blade support shaft 42, but the blade support shaft may be formed without the rolling bearing.

The blade support shaft 42 has a fixed portion 42a at one end in the axial direction of its own central axis C2, which has an outer diameter smaller than the outer diameter at the other end. A fastening member 61, which will be described later, is fastened and fixed to the fixed portion 42a. The fixed portion 42a has screw holes 42b in two locations, for example, spaced 180° apart. The screw holes 42b communicate with the storage portion 42c, which will be described later. A hexagon socket set screw 59 is screwed into each of the screw holes 42b provided at two locations on the outer circumferential surface of the fixed portion 42a.

The blade support shaft 42 has a recessed storage section 42c at one end where the fixing section 42a is provided. The storage section 42c stores one end of the adapter 51 to which the cutting blade 43 is fixed, and holds the cutting blade 43 coaxially with the central axis C2.

The machining blade 43 cuts the pilot hole 90 of the workpiece W, and processes the cross-sectional shape of the hole formed in the workpiece W into the contour shape of the cutting edge surface 43a, which is the tip surface of the machining blade 43. The tip surface, the cutting edge surface 43a, coincides with a plane perpendicular to its own central axis C2. The machining blade 43 has multiple blades for cutting the pilot hole of the workpiece W at intervals relative to the machining blade 43, and has a cutting edge pressed against the workpiece W on one end side. In this embodiment, multiple blades for processing serration holes, which are a type of spline, are arranged at equal intervals in the circumferential direction. The cutting edge surface 43a perpendicular to the central axis C2 is formed at the tip of one end side of the multiple blades, and the pilot hole 90 is cut into the contour shape of the outer periphery of the cutting edge surface 43a. The cutting blade 43 has a truncated cone-shaped outer periphery that is approximately similar in cross section from one end, which is the cutting edge 43a, to the other end in the extension direction of a straight line (e.g., the central axis C2) perpendicular to the cutting edge 43a, and gradually reduces in diameter. When the cutting blade 43 is made truncated cone-shaped, the cutting edge 43a is formed on the bottom surface of the truncated cone, and the bottom surface corresponds to the tip surface. The central axis of the truncated cone coincides with the central axis C2 of the cutting blade 43.

Here, the taper angle θ2 on the tapered outer peripheral surface of the processing blade 43 is, for example, θ2 = 2.2°, whereas the intersection angle θ1 = 2.1° described above. The taper angle θ2 of the processing blade 43 may be an angle at which the tip surfaces of the multiple blades that form the outer peripheral surface of the processing blade 43 and the bottom surfaces between the multiple blades do not press against the processing surface of the workpiece W when the processing blade 43 cuts the workpiece W. However, if the taper angle θ2 is set to be greater than 0.3° than the angle θ1 between the central axis C2 of the blade support shaft 42 and the central axis C1 of the bearing portion 47 of the holder 41 described above, the cutting edge is likely to become acute, and if it is less than 0.05°, the processing resistance increases. Therefore, it is best to set the taper angle θ2 to be 0.1° greater than the angle θ1.

The cutting blade 43 has a through hole 54 with a key groove. The shaft 52 is inserted into the through hole 54, and when the shaft 52 is inserted, a key portion (protrusion) 57 provided on the shaft 52 is inserted into the key groove 55.

The adapter 51 is a member that holds the cutting blade 43 together with the shaft 52 and nut 53. The adapter 51 is a cylindrical member that is open at both ends and has a large diameter portion 51a at approximately the center in the axial direction of the central axis C2 or at a location slightly offset from that in the axial direction. When one end of the adapter 51 is inserted into the storage portion 42c of the blade support shaft 42, the large diameter portion 51a abuts against the end face 42d of the fixing portion 42a, restricting the insertion of the adapter 51 into the storage portion 42c.

The hollow space 51b of the adapter 51 functions as a through hole for inserting the shaft 52. A key groove 51c is provided along the extension direction of the central axis C2 on the inner wall surface facing the hollow space 51b that functions as a through hole. The adapter 51 also has a positioning hole 51d that communicates with the hollow space 51b on the outer peripheral surface of one of the two ends divided by the large diameter portion 51a. The positioning holes 51d are provided in two places on the outer peripheral surface of the adapter 51, spaced 180° apart. These positioning holes 51d are used to insert the tips of hexagon socket set screws 59 that are screwed into the screw holes 42b provided in two places on the outer peripheral surface of the fixing portion 42a when the fastening member 61 is held by the fixing portion 42a.

The shaft 52 is a member having a head 52a, a cylindrical portion 52b, and a threaded portion 52c, with a key portion (projection) 57 along the central axis C2 and a recess 58 in the cylindrical portion 52b. When the cutting blade 43 is fixed to the adapter 51, the shaft 52 is inserted through the insertion hole 54 of the cutting blade 43 and then through the hollow space 51b of the adapter 51. At this time, the key portion 57 provided on the shaft 52 is inserted across the key groove 55 of the cutting blade 43 and the key groove 51c of the adapter 51. This maintains the relative positions of the cutting blade 43 and the adapter 51 in the rotational direction about the shaft 52.

The recesses 58 are provided at two locations on the outer periphery of the cylindrical portion 52b of the shaft 52, spaced 180° apart, and are flat surfaces inclined toward the head 52a. When the adapter 51 to which the cutting blade 43 is fixed is inserted into the storage portion 42c of the blade support shaft 42, and a fastening member 61 (described later) is attached to the fixed portion 42a of the blade support shaft 42, the tips of the hexagon socket set screws 59 screwed into each of the screw holes 42b provided at two locations on the outer periphery of the fixed portion 42a are pressed into the recesses 58. This fixes the relative positions of the blade support shaft 42 and the fixed portion 42a.

As shown in FIG. 8, the rotation assistance mechanism 44 includes a fastening member 61 and a tool side jig 62. The fastening member 61 is a generally C-shaped member having a fastening hole 65 and a slit 66. The fastening member 61 has the slit 66, and thus has an insertion hole 67 at one end 61a located above the slit 66, and a screw hole 68 coaxial with the insertion hole 67 at the other end 61b located below the slit 66. A fastening screw 70 is inserted into the insertion hole 67, and the fastening screw 70 inserted into the insertion hole 67 is screwed into the screw hole 68.

The fastening hole 65 has an escape groove 65a extending upward and an escape groove 65b extending downward. For example, when the hexagonal socket set screw 59 is screwed into the fixing portion 42a and tightened, the hexagonal socket set screw 59 protrudes a predetermined amount from the outer circumferential surface of the fixing portion 42a. The escape grooves 65a and 65b are intended to avoid interference between the hexagonal socket set screw 59 protruding a predetermined amount from the outer circumferential surface of the fixing portion 42a and the fastening member 61. The fastening member 61 inserts the fixing portion 42a into the fastening hole 65 so that the hexagonal socket set screw 59 protruding from the outer circumferential surface of the fixing portion 42a is inserted into the escape grooves 65a and 65b, respectively. After inserting the fixing portion 42a into the fastening hole 65, the relative position of the fastening member 61 or the fixing portion 42a is changed to align the hexagonal socket set screw 59 with the insertion holes 71 and 72, and then the fastening screw 70 is tightened. When the fastening screw 70 is tightened, the inner peripheral surface of the fastening member 61 that faces the fastening hole 65 is pressed against the outer peripheral surface of the fixed portion 42a of the blade support shaft 42, and the fastening member 61 is tightened and fixed to the fixed portion 42a of the blade support shaft 42.

The fastening member 61 also has insertion holes 71, 72 that extend from the upper and lower surfaces (not shown) toward the fastening hole 65. The insertion holes 71, 72 are holes through which a hexagon socket wrench for the hexagon socket set screw 59 is inserted.

The tool side jig 62 is fixed to the fastening member 61 via the bracket 80. The bracket 80 has screw mounting holes 80a and 80b. When the bracket 80 is fixed to the fastening member 61, the bolt 81 is inserted through the screw mounting holes 80a and 80b and screwed into the screw holes 61d and 61e provided in the tongue piece 61c of the fastening member 61 to fasten the bracket 80. The weight members 74 and 75 are fixed to the front surface of the fastening member 61 with hexagon socket set screws 76 and 77, and serve as balance weights to eliminate the imbalance around the axis caused by attaching the tool side jig 62 to the fastening member 61 via the bracket 80. In addition, when the weight members 74 and 75 are attached to the fastening member 61, the hole diameter corresponding to the fastening hole 65 is set to be smaller than the fastening hole 65. This makes it easy to position the fastening member 61 in the axial direction by abutting the weight members 74 and 75 against the end surface 42d when fastening the fastening member 61 to the blade support shaft 42.

The tool side jig 62 is a member that is pressed by the spindle side jig 21 provided on one of the gripping jaws 16 of the chuck 17 of the rotating spindle 11 when machining the inner wall of the pilot hole 90 of the workpiece W, and transmits the rotational force of the chuck 17 to the blade support shaft 42. The tool side jig 62 has an abutment portion 85, a shaft portion 86, and a threaded portion 87. The tool side jig 62 corresponds to the first jig described in the claims.

When machining the inner wall of the pilot hole 90 of the workpiece W, the abutment portion 85 abuts against the spindle side jig 21 provided on one of the gripping jaws 16 of the chuck 17 of the rotating spindle 11. The abutment portion 85 has a first abutment portion 85a having a conical shape and a second abutment portion 85b having an outer peripheral surface that is curved so as to be convex outward. The shape of the tip of the first abutment portion 85a is, for example, a spherical shape. The shape of the second abutment portion 85b is, for example, the shape of a sphere obtained when a sphere is cut by two parallel planes at the same distance from the center of the sphere (hereinafter, a sphere truncated shape). In other words, since the outer peripheral surface of the second abutment portion 85b is a spherical zone, the distance from the center of the second abutment portion 85b (i.e., the center of the sphere) P5 to the outer peripheral surface of the second abutment portion 85b is the radius R of the sphere including the sphere truncated shape (see FIG. 4).

When the tool rest 12 is moved toward the rotating spindle 11, the first contact portion 85a contacts the ridge line 25 between the upper surface 23 and the side surface 24 of the spindle-side jig 21. As the tool rest 12 moves toward the spindle 11, the second contact portion 85b moves from a state in which the first contact portion 85a contacts the ridge line 25 between the upper surface 23 and the side surface 24 of the spindle-side jig 21 to a state in which the second contact portion 85b contacts the side surface 24 of the spindle-side jig 21. The position at which the side surface 24 of the spindle-side jig 21 contacts the second contact portion 85b is on a plane PL2 that includes the cutting edge surface 43a of the machining blade 43.

In the embodiment, the contact portion 85 is a combination of a cone-shaped first contact portion 85a and a spherical trapezoid-shaped second contact portion 85b. However, the position where the side surface 24 of the spindle side jig 21 contacts the second contact portion 85b (the position of the contact point P2 described later) may be on a plane PL2 (see FIG. 5) including the cutting edge surface 43a of the machining blade 43. Therefore, the contact portion 85 may be a triangular pyramid or quadrangular pyramid member, for example, and the edge portion (ridge portion) of this member may be brought into contact with the side surface 24 of the spindle side jig 21. In addition, the tip of the shaft portion of the tool side jig may be bent so as to face the side surface of the spindle side jig, and the tip of the shaft portion of the tool side jig may be brought into contact (point contact) with the side surface of the spindle side jig.

Furthermore, as shown in Figures 9(a) and 9(b), the abutment portion 85' may be a plate member 85' inclined with respect to the central axis C4' of the shaft portion 86' so that the other end edge (ridge portion) 85a', which is opposite to the one end portion that is the tip side of the shaft portion 86' in the direction of the central axis C4' of the shaft portion 86', abuts against the side surface 24 of the spindle-side jig 21. In this case, the other end edge (ridge portion) 85a' abuts against the side surface 24 of the spindle-side jig 21.

The screw portion 87 is screwed into the screw hole 80c of the bracket 80. The position of the abutment portion 85 in the direction parallel to the central axis C4 of the tool side jig 62 is adjusted by the degree of tightening of the screw portion 87 into the screw hole 80c of the bracket 80. In this embodiment, the degree of tightening of the screw portion 87 of the tool side jig 62 is adjusted so that the point P2 at which the side surface 24 of the spindle side jig 21 abuts against the second abutment portion 85b is located on the plane PL2 including the cutting edge surface 43a of the cutting blade 43 when the machining tool 40 is in use. In this state, the first abutment portion 85a of the abutment portion 85 protrudes from the plane PL2 including the cutting edge surface 43a of the cutting blade 43 in the direction along the central axis C2 of the blade support shaft 42.

The nut 88 is screwed into the threaded portion 87 of the tool side jig 62 that protrudes from the screw hole 80c of the bracket 80 to the rear side of the bracket 80. The nut 88 is a lock nut to prevent the tool side jig 62, which is adjusted and fixed to the bracket 80, from being displaced relative to the bracket 80. Since the tool side jig 62 is screwed into the screw hole 80c of the bracket 80 and attached, the second abutment portion 85b is made spherical and frustum-shaped. However, it is sufficient that the shape does not rotate relatively around the central axis C3 of the holder 41 of the machining tool 40 even if it abuts and slides against the side surface 24 of the spindle side jig 21 when the workpiece W and the machining blade 43 are in contact. The shape that does not rotate relatively around the central axis C3 is sufficient that the side surface 24 is parallel to a plane including the central axis C3, the second abutment portion 85b has at least a point or a linear abutment portion, and is positioned so that it can abut against the side surface 24 during machining. The second contact portion 85b does not need to be a convex curved surface, and may be formed as a flat surface. If it is a flat surface, it is preferable that it is parallel to the side surface 24.

Next, the operation of serration machining of the inner wall of the pilot hole 90 of the workpiece W will be described. The workpiece W is attached to the chuck 17 by the three gripping jaws 16a, 16b, and 16c of the chuck 17. With the workpiece W held by the three gripping jaws 16a, 16b, and 16c and attached to the chuck 17, the spindle 11 rotates in the R1 direction in FIG. 3 around the central axis C1. A pilot hole is machined in the workpiece W by a circular pilot hole machining blade (not shown). After the pilot hole machining is completed, the central axis C3 of the machining tool 40 for serration machining, which is attached in advance to the tool holding portion 35 of the tool rest 12, is aligned with the central axis C1 of the spindle 11, which is the axis of the pilot hole, by using a swivel drive unit or the like, and moved toward the spindle 11. When the tool rest 12 moves toward the spindle 11, the spindle 11 and the holder 41 of the machining tool 40 are held in a concentric state.

As described above, when the tool rest 12 moves toward the spindle 11, in the direction of the central axis C1 of the spindle 11, a part of the abutment portion 85 of the tool side jig 62 of the machining tool 40 reaches within the presence area through which the pressing piece 21b of the spindle side jig 21 of the gripping jaws 16a passes by rotation, as shown in Figures 10(a) and 10(b). Note that, in a projection plane perpendicular to the central axis C1 of the spindle 11, if the spindle side jig 21 fixed to the gripping jaws 16a has already passed the position of the abutment portion 85 of the tool side jig 62, the spindle side jig 21 fixed to the gripping jaws 16a rotates without pressing the abutment portion 85 of the tool side jig 62.

However, when the spindle-side jig 21 fixed to the gripping jaws 16a rotates to the position of the abutment portion 85 of the tool-side jig 62 as shown in Figures 11(a) and 11(b), the ridge line 25 formed by the upper surface 23 and side surface 24 of the spindle-side jig 21 abuts against the first abutment portion 85a of the tool-side jig 62, and the spindle-side jig 21 presses against the tool-side jig 62. In Figure 11(b), the symbol P1 indicates the abutment point where the ridge line 25 formed by the upper surface 23 and side surface 24 of the spindle-side jig 21 abuts against the first abutment portion 85a of the tool-side jig 62.

As described above, the tool side jig 62 is fixed to the blade support shaft 42 as the rotation assist mechanism 44. When the spindle side jig 21 presses the tool side jig 62, the pressing force is transmitted to the blade support shaft 42 via the rotation assist mechanism 44, and the blade support shaft 42 rotates (spins) around the central axis C2. At this time, the rotation center P3 (see FIG. 11(b)) of the cutting edge surface 43a of the cutting blade 43, which is the intersection point between the cutting edge surface 43a of the cutting blade 43 and the central axis C2 of the blade support shaft 42, is located on the central axis C1 of the spindle 11. On the other hand, the abutment point P1 is not on the plane PL2 including the cutting edge surface 43a of the cutting blade 43, but is located at a distance D away from the plane PL2 toward the spindle 11 in the direction of the central axis C2 of the blade support shaft 42. Here, the intersection point between the plane parallel to the plane PL2, including the abutment point P1, and the central axis C2 of the blade support shaft 42, i.e., the center of rotation of the abutment point P1 when the spindle side jig 21 presses the tool side jig 62, is offset from the central axis C1 of the spindle 11. As a result, while the spindle 11 rotates at a constant angular velocity, the blade support shaft 42 rotates while its angular velocity does not completely match that of the spindle 11 and changes periodically.

In addition, even after the blade support shaft 42 to which the machining blade 43 is fixed starts to rotate together with the spindle 11, the tool rest 12 continues to move toward the spindle 11. Therefore, the position at which the ridge 25 formed by the top surface 23 and side surface 24 of the spindle-side jig 21 abuts against the first abutment portion 85a of the tool-side jig 62 shifts from the one end side (z side) where the abutment portion 85 of the tool-side jig 62 is provided to the other end side (-z side).

As the above-described misalignment progresses, as shown in FIG. 12(a), the ridge 25 formed by the top surface 23 and side surface 24 of the spindle-side jig 21 is released from contact with the first contact portion 85a, and is replaced by contact with the second contact portion 85b on the side surface 24 of the spindle-side jig 21. The symbol P2 indicates the point where the second contact portion 85b contacts the side surface 24 of the spindle-side jig 21.

Even after the side surface 24 of the spindle-side jig 21 abuts against the second abutment portion 85b of the tool-side jig 62, the tool rest 12 continues to move toward the spindle 11. Therefore, the second abutment portion 85b of the tool-side jig 62 slides while being pressed against the side surface 24 of the rotating spindle-side jig 21. In other words, the position of the abutment point P2 where the side surface 24 of the spindle-side jig 21 and the second abutment portion 85b of the tool-side jig 62 abut against each other moves toward the spindle 11. In addition, since the central axis C2 of the blade support shaft 42 is inclined at a predetermined angle θ1 with respect to the central axis C1 of the spindle 11, when the tool side jig 62 rotates by being pressed against the side surface 24 of the rotating spindle side jig 21, the position of the abutment point P2 where the side surface 24 of the spindle side jig 21 and the second abutment portion 85b abut slides in the width direction of the side surface 24 of the spindle side jig 21, that is, in the radial direction of the rotation trajectory of the rotating spindle side jig 21. As described above, since the second abutment portion 85b has the shape of a spherical truncation formed by cutting a sphere with two parallel planes at the same distance from the center of the sphere, the distance from the center of the second abutment portion 85b, i.e., the center P5 of the spherical truncation to the abutment point P2, is constant at the radius R of the second abutment portion 85b.

As described above, the spindle-side jig 21 rotates around the central axis C1 of the spindle 11, and the cutting blade 43 and the tool-side jig 62 rotate around the central axis C2 of the blade-supporting shaft 42. At this time, the abutment point P2 between the side surface 24 of the spindle-side jig 21 and the abutment portion 85 of the tool-side jig 62 is on a plane PL2 including the rotation center P3 of the cutting edge surface 43a of the cutting blade 43, so the abutment point P2 rotates around the rotation center P3 of the cutting edge surface 43a of the cutting blade 43. As a result, even if the central axis C2 of the cutting blade 43 is inclined at an angle θ1 with respect to the central axis C1 of the spindle 11, the rotation angle of the workpiece W attached to the chuck 17 of the spindle 11 and the rotation angle of the cutting edge surface 43a of the cutting blade 43 are matched (synchronized), and no deviation in the rotation angle occurs.

Even after the spindle-side jig 21 switches to abutment against the second abutment portion 85b on the side surface 24 of the spindle-side jig 21, the spindle-side jig 21 continues to press against the abutment portion 85 of the tool-side jig 62. Then, as shown in FIG. 12(b), the cutting blade 43 of the machining tool 40 is pressed against the workpiece W, and cutting of the workpiece W by the cutting blade 43 begins.

The cutting blade 43 rotates around the central axis C2 in perfect synchronization with the rotation of the workpiece W. At this time, the central axis C2 of the cutting blade 43 is inclined at an angle θ1 with respect to the central axis C1 of the spindle 11, and intersects with the central axis Z1 at the rotation center P3 of the cutting edge surface 43a of the cutting blade 43. Therefore, the central axis C2 of the cutting blade 43 rotates relatively around the central axis C1 of the spindle 11 while remaining inclined, and the central axis C2 performs a relative swinging motion like the motion locus of a conical pendulum with respect to the workpiece W with the rotation center P3 as the base point. As the tool rest 12 moves toward the spindle 11 (i.e., the feed of the tool rest 12), the cutting blade 43 is locally pressed against the workpiece W as it rotates, and cuts the inner wall of the pilot hole 90 from the edge. As a result, the pilot hole 90 in the workpiece W is cut along the contour shape of the cutting edge surface 43a of the cutting blade 43.

As described above, when the inner wall of the pilot hole 90 of the workpiece W is cut by the cutting blade 43, the rotation center of the abutment point P2 where the side surface 24 of the spindle side jig 21 and the second abutment portion 85b of the tool side jig 62 abut is coincident with the rotation center P3 of the cutting edge surface 43a of the cutting blade 43. In addition, the rotation center P3 of the cutting edge surface 43a of the cutting blade 43 is on the central axis C1 of the spindle 11. Therefore, the blade support shaft 42 does not rotate relative to the workpiece W around the central axis C1 of the spindle 11 that rotates integrally with the workpiece W, and only the central axis C2 moves forward in the feed direction while performing a swinging motion like the motion locus of a conical pendulum. As a result, as shown in Figures 13(a) and 13(b), a spline-shaped hole 150 is formed in the workpiece W along the cutting edge surface of the cutting blade 43. In this spline-shaped hole 150, the multiple teeth 151 formed along the inner circumferential surface of the hole 150 are not missing on the end surface 91 side of the workpiece W where the cutting edge surface 43a of the machining blade 43 begins to press, and the multiple teeth 151 do not extend in a serpentine manner in the direction of the central axis C6 of the workpiece W, but rather extend linearly along the central axis C6 of the workpiece W. In this way, by adopting the above embodiment, a spline-shaped hole can be machined with high precision in the workpiece W.

When the movement of the tool rest 12 toward the spindle 11 reaches a predetermined amount, the tool rest 12 moves back to its original position. The rotation of the spindle 11 in the R1 direction also stops. In this state, it is possible to release the grip of the workpiece W by the three gripping jaws 16 of the chuck 17. Therefore, after the machined workpiece W is removed, if there is a new workpiece W to be machined, the machined workpiece W is removed and replaced with the new workpiece W to be machined.

When machining the workpiece W, the spindle 11 rotates around the central axis C1, and at the same time, the tool rest 12 moves toward the rotating spindle 11. When the tool rest 12 moves toward the rotating spindle 11, the abutment portion 85 of the tool side jig 62 enters the presence area (rotation trajectory) of the spindle side jig 21 accompanying the rotation of the spindle 11. For example, when the abutment portion 85 of the tool side jig 62 enters the presence area of the spindle side jig 21 accompanying the rotation of the spindle 11 in a state in which the pressing piece 21b of the spindle side jig 21 has not yet reached the position of the abutment portion 85 of the tool side jig 62 on the projection plane perpendicular to the central axis C1 of the spindle 11, the abutment portion 85 of the tool side jig 62 is pressed against the pressing piece 21b of the spindle side jig 21 the next time the pressing piece 21b of the spindle side jig 21 reaches the above-mentioned position.

As shown in FIG. 14(a), in a projection plane perpendicular to the central axis C1 of the spindle 11, for example, when the tool rest 12 moves toward the spindle 11, the upper surface 23 of the spindle-side jig 21 of the rotating spindle 11 overlaps with the abutment portion 85 of the tool-side jig 62, and the abutment portion 85 of the tool-side jig 62 enters the area of the spindle-side jig 21 caused by the rotation of the spindle 11. The tip of the abutment portion 85 of the tool-side jig 62 abuts against the pin 27 protruding from the upper surface 23 of the pressing piece 21b of the spindle-side jig 21 (see FIG. 14(b)).

When the tip of the contact portion 85 of the tool side jig 62 contacts the pin 27, the pin 27 is pressed by the tip of the contact portion 85 of the tool side jig 62 and pushed into the inside of the pressing piece 21b. At this time, the pin 27 pressed by the contact portion 85 of the tool side jig 62 is biased by a spring, and the contact portion 85 of the tool side jig 62 and the pin 27 are engaged.

Even when the tool side jig 62 is engaged with the pin 27, the spindle 11 rotates, and at the same time, the tool rest 12 moves toward the spindle 11. When the contact portion 85 of the tool side jig 62 engages with the pin 27, the contact portion 85 of the tool side jig 62 starts to rotate together with the spindle 11, rotating the blade support shaft 42 to which the cutting blade 43 and the rotation assistance mechanism 44 are fixed. At this time, a force acts on the tool side jig 62 to stop the rotation of the blade support shaft 42, so the position where the tip of the contact portion 85 of the tool side jig 62 presses the tip of the pin 27 shifts, and before the tip of the contact portion 85 of the tool side jig 62 hits the upper surface 23 of the pressing piece 21b, the engagement between the tip of the contact portion 85 of the tool side jig 62 and the tip of the pin 27 is released. When the pressure contact between the tip of the abutment portion 85 of the tool side jig 62 and the tip of the pin 27 is released, the tool side jig 62 rotates a predetermined amount in the direction opposite to the spindle 11 and stops. The pin 27 also returns to its original position due to the bias of the spring.

When the tool rest 12 moves toward the spindle 11 and the abutment portion 85 of the tool side jig 62 enters the area passed by due to the rotation of the pressing piece 21b, it is pressed by the pressing piece 21b of the spindle side jig 21 fixed to the spindle 11. As a result, the blade support shaft 42 to which the machining blade 43 and the rotation assist mechanism 44 are fixed rotates together with the spindle 11. This prevents the tip of the abutment portion 85 of the tool side jig 62 from coming into pressure contact with the upper surface 23 of the pressing piece 21b of the spindle side jig 21. As a method to prevent damage to the jig by strongly pressing against the upper surface 23 of the pressing piece 21b of the spindle side jig 21, it is possible to provide an escape mechanism for the impact of the abutment part 85 on the rotation assistance mechanism 44 attached to the tool side jig, but a mechanism that allows the abutment part 85 to move relative to the cutting blade 43 has poor positional accuracy between the two during processing.

In the embodiment described above, the spindle side jig 21 is fixed to one of the three gripping jaws 16 of the chuck 17. However, the spindle side jig may be fixed to the chuck 17 instead of to one of the three gripping jaws 16. In the following, since the configuration of the machining tool is the same as in the above-mentioned embodiment, the same reference numerals as in the above-mentioned embodiment are used to describe each part of the machining tool.

As shown in FIG. 15, the spindle side jig 100 is fixed to the chuck 102 of the spindle 101 while being disposed in each area between three gripping jaws 103 provided on the chuck 102. FIG. 15 shows a case where the spindle side jig 100 is disposed in all areas between adjacent gripping jaws 103, but the spindle side jig 100 may be disposed in any of the areas between adjacent gripping jaws 103.

The spindle side jig 100 has a base 105 fixed to the chuck 102, and a pressing piece 106 extending from the base 105 along the central axis C5 of the spindle 101. The base 105 is fixed to the chuck 102 by a bolt 108. The pressing piece 106 has a pin 109 that protrudes from the tip surface 106a of the pressing piece 106 due to the bias of a coil spring (not shown) provided inside. Here, the tip surface 106a of the pressing piece 106 is located on the machining tool 40 side relative to the end surface 91 of the workpiece W held by the gripping jaws 103.

When the spindle side jig 100 is fixed to the chuck 102, as in the case of the spindle side jig 21 shown in the embodiment described above, when the machining tool 40 moves towards the spindle 101 and the abutment portion 85 of the tool side jig 62 enters the presence area of the spindle side jig 100, the pressing piece 106 of the spindle side jig 100 presses the abutment portion 85 of the tool side jig 62, and the rotation of the spindle 11 is synchronized with the rotation of the blade support shaft 42 to which the machining blade 43 and the rotation assist mechanism 44 are fixed. On the other hand, when the abutment portion 85 of the tool side jig 62 abuts against the pin 109 of the spindle side jig 100, the abutment portion 85 of the tool side jig 62 presses the pin 109 of the spindle side jig 100. However, in the process of pushing the pin 109 into the inside of the pressing piece 106, the engagement between the abutment portion 85 of the tool side jig 62 and the pin 109 of the spindle side jig 100 is released, and when the abutment portion 85 of the tool side jig 62 enters the existence area through which the pressing piece 106 passes by due to the rotation of the pressing piece 106, the abutment portion 85 of the tool side jig 62 is pressed against the pressing piece 106. As a result, the blade support shaft 42 to which the cutting blade 43 and the rotation assistance mechanism 44 are fixed rotates together with the spindle 101.

In the embodiment described above, the spindle 11 holding the workpiece W is rotated while the tool rest 12 holding the machining tool 40 is moved toward the rotating workpiece W without rotating. However, instead of rotating the spindle 11 holding the workpiece W, it is also possible to rotate the machining tool 40 fixed to the tool rest 12 and simultaneously move either the workpiece W or the tool rest 12 toward the other. For example, instead of rotating the workpiece W, rotating the machining tool 40 fixed to the tool rest 12 is effective, for example, when machining a pilot hole located at a position offset from the center of the workpiece W with the machining tool 40, or when machining multiple workpieces simultaneously with multiple machining tools 40. Furthermore, it is necessary to fix multiple spindle side jigs to the chuck or gripping jaws, but it is also effective when machining multiple pilot holes formed in the workpiece W by the machining tool 40 simultaneously or individually. In such a case, it is necessary to make the center axis C1 of the spindle 11 and the tool rest 12 concentric, but rather to make the pilot hole in the workpiece W concentric with the center axis C3 of the holder 41 of the machining tool 40 that processes the pilot hole.

In the embodiment described above, the case where serration machining is performed on a workpiece W in which a pilot hole 90 has been formed using a machine tool 10 is described. However, it is also possible to perform other turning operations, including drilling pilot holes 90, and the above-mentioned serration machining on the workpiece W in succession using the same machine tool 10. In this way, by performing multiple machining operations in succession using the same machine tool, the workpiece W can be machined with high precision, and steps in each machining operation can be omitted, shortening the machining time for the workpiece W.

The machining tool shown in the embodiment described above has a machining blade 43 that machines the workpiece W attached to the chuck 17, a blade support shaft 42 that holds the machining blade 43 at one end in the direction of its own central axis C2, a holder 41 that holds the blade support shaft 42 rotatably around the central axis C2 of the blade support shaft 42, and a tool side jig 62 provided on the blade support shaft 42, and the holder 41 holds the blade support shaft 42 with the central axis C2 of the blade support shaft 42 inclined relative to its own central axis C3, and the machining blade 43 is configured to rotate when the blade support shaft 42 is held by the holder 41. The center of rotation P3 at the tip surface of the body 43 is arranged to coincide with the intersection point between the central axis C3 of the holder 41 and the central axis C2 of the blade support shaft 42, and the tool side jig 62 abuts against the spindle side jig 21 provided on the chuck 17 on a plane PL2 that is perpendicular to the central axis of the blade support shaft 42 and includes the above-mentioned intersection point when the chuck 17 and holder 41 are brought close to each other while rotating either the chuck 17 or the holder 41 about its own central axis C1, C3 as the center of rotation, thereby aligning the rotational position of the workpiece W with the rotational position of the cutting blade 43 in the rotational direction of either the rotating chuck 17 or the holder 41.

According to this, the rotation center of the abutment point P2 where the pressing piece 21b of the spindle side jig 21 and the abutment portion 85 of the tool side jig 62 abut is coincident with the rotation center P3 of the cutting edge surface 43a of the cutting blade 43. In addition, the rotation center P3 of the cutting edge surface 43a of the cutting blade 43 is coincident with the intersection point of the central axis C3 of the holder 41 and the central axis C2 of the blade support shaft 42. Furthermore, when the workpiece W is processed, the chuck 17 and the holder 41 are held in a concentric state. As a result, when projected onto a plane perpendicular to the central axis C1 of the chuck 17, there is no misalignment between the angle at which the rotating chuck 17 or holder 41 rotates and the angle at which the position at which the cutting blade 43 is locally pressed against the workpiece W rotates, and the rotation of the chuck 17 or holder 41 and the rotation of the position at which the cutting blade 43 is locally pressed against the workpiece W can be synchronized. In other words, even if the chuck 17 or holder 41 is rotated for processing, the cutting blade 43 can maintain the relative rotation between the workpiece W and the cutting blade 43 at zero by simply swinging its own central axis C2 relative to the workpiece W like the motion locus of a conical pendulum with the rotation center P3 of the cutting edge surface 43a as the base point. As a result, the cutting of the workpiece W by the cutting blade 43 can be performed with high precision. In addition, before the cutting of the workpiece W by the cutting blade 43, the rotation of the chuck 17 or holder 41 and the rotation of the position where the cutting blade 43 is locally pressed against the workpiece W are synchronized, so that the impact when the cutting blade 43 is pressed against the workpiece W can be reduced, and damage to the cutting edge surface 43a of the cutting blade 43 can be prevented.

In addition, when the rotating chuck 17 and holder 41 are brought close together while the chuck 17 and holder 41 are held concentrically, the tool side jig 62 receives pressure from the spindle side jig 21 which rotates with the rotation of the chuck 17, causing the blade support shaft 42 to rotate around the central axis C2 of the blade support shaft 42, and the machining blade 43 oscillates around the intersection point relative to the workpiece W.

According to this, when the cutting blade 43 is pressed against the workpiece W, the cutting blade 43 performs a swinging motion with the center of rotation P3 of the cutting edge surface 43a of the cutting blade 43 as the base point. As described above, the center of rotation P3 of the cutting edge surface 43a of the cutting blade 43 is located on the central axis C1 of the chuck 17. Therefore, the above-mentioned pressure contact point performs cutting processing without causing positional deviation in the rotation direction of the chuck 17 between the workpiece W fixed to the rotating chuck 17. As a result, cutting processing of the workpiece W by the cutting blade 43 can be performed with high precision.

When the rotating holder 41 and the chuck 17 are brought close to each other, the tool side jig 62 comes into contact with the spindle side jig 21, stopping the rotation of the blade support shaft 42 that accompanies the rotation of the holder 41. Since the central axis C2 of the blade support shaft 42 is inclined relative to the central axis C3 of the holder 41, the machining blade 43 oscillates around the intersection together with the blade support shaft 42 as a result of the rotation of the holder 41 that continues after the rotation of the blade support shaft 42 has stopped.

According to this, when the processing blade 43 is pressed against the workpiece W, the processing blade 43 performs a swinging motion with the rotation center P3 of the cutting edge surface 43a of the processing blade 43 as the base point. As described above, the rotation center P3 of the cutting edge surface 43a of the processing blade 43 is located on the central axis C1 of the chuck 17. Therefore, the above-mentioned pressure contact point moves by the same angle as the rotation angle of the rotating holder 41. In addition, the rotation center P3 of the cutting edge surface 43a of the processing blade 43 is located on the central axis C1 of the chuck 17. As a result, the swinging processing blade 43 is uniformly pressed against the workpiece W, and the cutting processing of the workpiece W by the processing blade 43 can be performed with high precision. In this case, for example, even when machining a pilot hole located at a position offset from the center of the workpiece W using the processing tool 40, or when machining multiple workpieces W simultaneously using multiple processing tools 40, cutting processing can be performed with high precision.

The tool side jig 62 also has an abutment portion 85 that abuts against the spindle side jig 21 by point contact or line contact. The tool side jig 62 has an abutment portion that can make point contact or line contact with the spindle side jig 21 when abutting against the spindle side jig 21.

According to this, when the tool side jig 62 and the spindle side jig 21 abut, the abutment portion 85 of the tool side jig 62 makes point or line contact with the spindle side jig 21, so that, for example, when the spindle 11 rotates, the tool side jig 62 is reliably pressed against the spindle side jig 21. Therefore, although the chuck 17 rotates together with the spindle 11, there is no misalignment between the rotation angle of the chuck 17 and the rotation angle of the position where the machining blade 43 is locally pressed against the workpiece W, and the rotation of the chuck 17 provided on the spindle 11 can be synchronized with the rotation of the position where the machining blade 43 is locally pressed against the workpiece W. In addition, when the machining tool 40 rotates, the spindle side jig 21 comes into contact with the tool side jig 62, so that, in the same manner as when the spindle 11 rotates, the rotational position of the chuck 17 provided on the spindle 11 in the rotational direction of the holder 41 of the machining tool 40 can be synchronized with the rotational position of the position where the machining blade 43 is locally pressed against the workpiece W.

The spindle-side jig 21 is held in a protruding state from the spindle-side jig 21 by a spring force, and has a pin 27 that is pressed by the tool-side jig 62 and pushed into the spindle-side jig 21 against the spring force when the holder 41 and the chuck 17 approach each other.

For example, when the tool side jig 62 enters the area through which the pressing piece 21b of the spindle side jig 21 of the gripping jaws 16a passes due to rotation, depending on the timing of the entry, the abutment portion 85 of the tool side jig 62 collides with the upper surface 23 of the pressing piece 21b of the spindle side jig 21. In this case, the abutment portion 85 of the tool side jig 62 rotates with the spindle 11 while pressing the upper surface 23 of the pressing piece 21b of the spindle side jig 21, and the machining blade 43 of the machining tool 40 cannot be pressed against the workpiece W, i.e., the workpiece cannot be machined.

With the above configuration, when the contact portion 85 of the tool side jig 62 contacts the pin 27, the pin 27 engages with the contact portion 85 of the tool side jig 62. At this time, the chuck 17 is rotating, while the blade support shaft 42 is stopped. Therefore, the contact portion 85 of the tool side jig 62 is subjected to a force pressing the pin 27, a force acting due to the rotation of the chuck 17, and a dynamic friction force acting between the pin 27 and the contact portion 85 of the tool side jig 62. Due to these forces, the blade support shaft 42 to which the tool side jig 62 is attached rotates in the same direction as the rotation direction of the chuck 17, but at a slower speed than the rotation of the chuck 17. The blade support shaft 42 to which the tool side jig 62 is attached rotates at a slower speed than the chuck 17, and thus the engagement between the contact portion 85 of the tool side jig 62 and the pin 27 is released. At this time, the spindle side jig 21 provided on the gripping jaws 16 of the chuck 17 has rotated to a position retracted from the direction of travel of the tool side jig 62. Meanwhile, since the chuck 17 is rotating, the pressing piece 21b of the spindle side jig 21 attached to the chuck 17 presses the abutment portion 85 of the spindle side jig 21 moving toward the chuck 17. This prevents the abutment portion 85 of the tool side jig 62 from colliding with the upper surface 23 of the pressing piece 21b of the spindle side jig 21. As a result, the machining blade 43 of the machining tool 40 can be reliably pressed against the workpiece W.

When the holder 41 is rotating, the blade support shaft 42 and the tool side jig 62 attached to the blade support shaft 42 rotate together with the holder 41. When the holder 41 approaches the chuck 17, the abutment portion 85 of the tool side jig 62 attached to the rotating blade support shaft 42 collides with the upper surface 23 of the pressing piece 21b of the spindle side jig 21 of the tool side jig 62 provided on the gripping jaws 16 of the chuck 17. At this time, the holder 41 rotates, but the blade support shaft 42 and the tool side jig 62 stop rotating. In this state, the machining blade 43 of the machining tool 40 cannot be pressed against the workpiece W, i.e., the workpiece cannot be machined.

When the abutment portion 85 of the tool side jig 62 presses the pin 27 while the holder 41 of the machining tool 40 is rotating, the abutment portion 85 of the tool side jig 62 is subjected to a force pressing the pin 27, a force due to the rotation of the holder 41 of the machining tool 40, and a dynamic friction force acting between the abutment portion 85 and the pin 27 when the abutment portion 85 of the tool side jig 62 abuts the pin 27. Due to these forces, the blade support shaft 42 to which the tool side jig 62 is attached rotates in the same direction as the rotation direction of the holder 41, but at a slower speed than the rotation of the holder 41. Meanwhile, the spindle side jig 21 provided on the gripping jaws 16 of the chuck 17 is stopped. Therefore, the engagement between the abutment portion 85 of the tool side jig 62 and the pin 27 is released. At this time, in the rotation direction of the holder 41, the abutment portion 85 of the tool side jig 62 attached to the blade support shaft 42 held by the holder 41 rotates to a position offset from the spindle side jig 21 provided on the chuck 17. Also, when the engagement between the abutment portion 85 of the tool side jig 62 and the pin 27 is released, the blade support shaft 42 to which the tool side jig 62 is attached rotates together with the holder 41. At this time, since the holder 41 and the chuck 17 are close to each other, the abutment portion 85 of the tool side jig 62 abuts against the pressing piece 21b of the spindle side jig 21. This prevents the abutment portion 85 of the tool side jig 62 from colliding with the upper surface 23 of the pressing piece 21b of the spindle side jig 21. As a result, the machining blade 43 of the machining tool 40 can be reliably pressed against the workpiece W.

The machining blade 43 performs spline machining on the workpiece W.

For example, when the cutting blade 43 is pressed against the rotating workpiece W, the cutting blade 43 is subjected to a force based on the rotation of the workpiece and a force pressing the cutting blade 43 against the workpiece W. When the cutting blade 43 is pressed against the workpiece W, for example, the rotation angle of the workpiece W when the chuck 17 rotates and the rotation angle of the pressing contact point, or the rotation angle of the holder 41 when the holder 41 rotates and the rotation angle of the pressing contact point, are consistent. In other words, when the cutting blade 43 is pressed against the workpiece W, only the pressing force acts. As a result, damage to the cutting blade 43 can be prevented, and at the same time, poor cutting of the workpiece W due to chipping of the cutting edge surface 43a of the cutting blade 43 is suppressed. Furthermore, bending of the tooth line and poor cutting can be prevented.

The machine tool shown in the embodiment described above has a chuck 17 to which the workpiece W is attached, a machining tool 40 for machining the workpiece W, and a tool holding portion 35 for holding the machining tool 40. The machining tool 40 has a machining blade 43 for machining the workpiece W by being pressed against the workpiece W, a blade support shaft 42 for holding the machining blade 43 at one end side in the direction of its own central axis C2, a holder 41 for holding the blade support shaft 42 rotatably around the central axis C2 of the blade support shaft 42, and a tool side jig 62 provided on the blade support shaft 42. The chuck 17 has a spindle side jig 21 that comes into contact with the tool side jig 62 when machining the workpiece W, and the holder 41 has a center axis C2 of the blade support shaft 42 inclined relative to its own center axis C3. The blade support shaft 42 is held in this state, and the cutting blade 43 is arranged so that when the blade support shaft 42 is held in the holder 41, the center of rotation of the tip surface of the cutting blade 43 coincides with the intersection point between the central axis C3 of the holder 41 and the central axis C2 of the blade support shaft 42. When the chuck 17 and the holder 41 are brought close to each other while rotating either the chuck 17 or the holder 41 about its own central axis C1 or C3, the tool side jig 62 abuts against the spindle side jig 21 provided on the chuck 17 on a plane PL2 that is perpendicular to the central axis C2 of the blade support shaft 42 and includes the above-mentioned intersection point, thereby aligning the rotational position of the workpiece W with the rotational position of the cutting blade 43 in the rotational direction of either the rotating chuck 17 or the holder 41.

According to this, the rotation center of the abutment point P2 where the pressing piece 21b of the spindle side jig 21 and the abutment portion 85 of the tool side jig 62 abut is coincident with the rotation center P3 of the cutting edge surface 43a of the cutting blade 43. In addition, the rotation center P3 of the cutting edge surface 43a of the cutting blade 43 is coincident with the intersection point of the central axis C3 of the holder 41 and the central axis C2 of the blade support shaft 42. Furthermore, when the workpiece W is processed, the chuck 17 and the holder 41 are held in a concentric state. As a result, when projected onto a plane perpendicular to the central axis C1 of the chuck 17, there is no misalignment between the angle at which the rotating chuck 17 or holder 41 rotates and the angle at which the position at which the cutting blade 43 is locally pressed against the workpiece W rotates, and the rotation of the chuck 17 or holder 41 and the rotation of the position at which the cutting blade 43 is locally pressed against the workpiece W can be synchronized. As a result, the workpiece W can be machined with high precision by the machining blade 43. In addition, before machining the workpiece W with the machining blade 43, the rotation of the chuck 17 or holder 41 is synchronized with the rotation of the position where the machining blade 43 is locally pressed against the workpiece W, so that the impact when the machining blade 43 is pressed against the workpiece W can be reduced, and damage to the cutting edge 43a of the machining blade 43 can be prevented.

When the rotating chuck 17 and holder 41 are brought close together while the chuck 17 and holder 41 are held concentrically, the tool side jig 62 receives pressure from the spindle side jig 21 which rotates with the rotation of the chuck 17, causing the blade support shaft 42 to rotate around the central axis C2 of the blade support shaft 42, and the machining blade 43 oscillates around the intersection point relative to the workpiece W.

According to this, when the cutting blade 43 is pressed against the workpiece W, the cutting blade 43 performs a swinging motion with the center of rotation P3 of the cutting edge surface 43a of the cutting blade 43 as the base point. As described above, the center of rotation P3 of the cutting edge surface 43a of the cutting blade 43 is located on the central axis C1 of the chuck 17. Therefore, the above-mentioned pressure contact point performs cutting processing without causing positional deviation in the rotation direction of the chuck 17 between the workpiece W fixed to the rotating chuck 17. As a result, cutting processing of the workpiece W by the cutting blade 43 can be performed with high precision.

When the rotating holder 41 and the chuck 17 are brought close to each other, the tool side jig 62 comes into contact with the spindle side jig 21, stopping the rotation of the blade support shaft 42 that accompanies the rotation of the holder 41. Since the central axis C2 of the blade support shaft 42 is inclined relative to the central axis C3 of the holder 41, the machining blade 43 oscillates around the intersection with the blade support shaft 42 as a result of the rotation of the holder 41 that continues after the rotation of the blade support shaft 42 has stopped.

According to this, when the processing blade 43 is pressed against the workpiece W, the processing blade 43 performs a swinging motion with the rotation center P3 of the cutting edge surface 43a of the processing blade 43 as the base point. As described above, the rotation center P3 of the cutting edge surface 43a of the processing blade 43 is located on the central axis C1 of the chuck 17. Therefore, the above-mentioned pressure contact point moves by the same angle as the rotation angle of the rotating holder 41. In addition, the rotation center P3 of the cutting edge surface 43a of the processing blade 43 is located on the central axis C1 of the chuck 17. As a result, the swinging processing blade 43 is uniformly pressed against the workpiece W, and the cutting processing of the workpiece W by the processing blade 43 can be performed with high precision. In this case, for example, even when machining a pilot hole located at a position offset from the center of the workpiece W using the processing tool 40, or when machining multiple workpieces W simultaneously using multiple processing tools 40, cutting processing can be performed with high precision.

The chuck 17 has multiple gripping jaws 16, and the spindle side jig 21 is fixed to one of the multiple gripping jaws 16.

With this, it is only necessary to fix the pressing member to one of the gripping jaws of the chuck, and there is no need to create a new structure for the spindle or chuck. Therefore, it is also possible to fix it to the gripping jaws of a conventional machine tool.

In addition, the processing method in this embodiment is a method of processing a workpiece W attached to the chuck 17 using a processing tool 40 held by a holding device, and the processing tool 40 has a processing blade 43 that processes the workpiece W by being pressed against the workpiece W, a blade body support shaft 42 that holds the processing blade 43 at one end side in the direction of its own central axis C2, a holder 41 that holds the blade body support shaft 42 so that it can rotate around the central axis C2 of the blade body support shaft 42, and a tool side jig 62 provided on the blade body support shaft 42, and the chuck 17 has a spindle side jig 21 that abuts against the tool side jig 62 when processing the workpiece W, and the holder 41 holds the blade body support shaft 42 with the central axis C2 of the blade body support shaft 42 inclined relative to its own central axis C3, and the processing blade 43 is a blade body support When the holding shaft 42 is held by the holder 41, the rotation center P3 at the tip surface of the cutting blade 43 is arranged to coincide with the intersection point between the central axis C3 of the holder 41 and the central axis C2 of the blade support shaft 42, and either the chuck 17 or the holder 41 is rotated about its own central axis C1, C3; the chuck 17 and the holder 41 are brought close to each other, and abutted against the spindle side jig 21 provided on the chuck 17 on a plane PL2 that is perpendicular to the central axis C2 of the blade support shaft 42 and includes the above-mentioned intersection point, thereby matching the rotational position of the work W and the rotational position of the cutting blade 43 in the rotational direction of either the rotating chuck 17 or the holder 41; and the cutting blade 43 of the machining tool 40 is pressed against the work W to machine the work W.

According to this, the rotation center of the abutment point P2 where the pressing piece 21b of the spindle side jig 21 and the abutment portion 85 of the tool side jig 62 abut is coincident with the rotation center P3 of the cutting edge surface 43a of the cutting blade 43. In addition, the rotation center P3 of the cutting edge surface 43a of the cutting blade 43 is coincident with the intersection point of the central axis C3 of the holder 41 and the central axis C2 of the blade support shaft 42. Furthermore, when the workpiece W is processed, the chuck 17 and the holder 41 are held in a concentric state. As a result, when projected onto a plane perpendicular to the central axis C1 of the chuck 17, there is no misalignment between the angle at which the rotating chuck 17 or holder 41 rotates and the angle at which the position at which the cutting blade 43 is locally pressed against the workpiece W rotates, and the rotation of the chuck 17 or holder 41 and the rotation of the position at which the cutting blade 43 is locally pressed against the workpiece W can be synchronized. As a result, the workpiece W can be machined with high precision by the machining blade 43. In addition, before machining the workpiece W with the machining blade 43, the rotation of the chuck 17 or holder 41 is synchronized with the rotation of the position where the machining blade 43 is locally pressed against the workpiece W, so that the impact when the machining blade 43 is pressed against the workpiece W can be reduced, and damage to the cutting edge 43a of the machining blade 43 can be prevented.

The process of machining the workpiece W is also a process of spline machining the pilot holes provided in the workpiece W.

For example, by continuously using the same machine tool to perform the turning of pilot holes in the workpiece W and the serration machining of the pilot holes in the workpiece W formed by the turning, the workpiece W can be machined with high precision, and steps in each machining process can be omitted, shortening the machining time for the workpiece W.

10...Machine tool 11...Main spindle 12...Turret rest 16...Gripping claw 17...Chuck 21...Main spindle side jig 27...Pin 40...Machining tool 41...Holder 42...Blade support shaft 43...Processing blade 44 ...Rotation auxiliary mechanism 62...Tool side jig 85a...First abutting part 85b...Second abutting part W...Work

Claims (11)

A processing blade for processing a workpiece attached to a fixture;
a holder shaft for holding the cutting blade at one end in a direction of a central axis of the holder shaft;
a holder that holds the holder shaft so as to be rotatable about a central axis of the holder shaft;
A first jig provided on the holder shaft;
having
the holder holds the holder shaft with a central axis of the holder shaft inclined relative to a central axis of the holder itself,
the cutting blade is disposed such that, when the holding shaft is held by the holder, a rotation center at a tip surface of the cutting blade coincides with an intersection point between a central axis of the holder and a central axis of the holding shaft;
The first jig abuts against a second jig provided on the fixing tool on a plane perpendicular to the central axis of the holding shaft and including the intersection point when the fixing tool and the holder are brought close together while rotating either the fixing tool or the holder about their own central axis as the center of rotation, thereby aligning the rotational position of the workpiece with the rotational position of the machining blade in the rotational direction of either the rotating fixing tool or the holder. The machining tool according to claim 1,
When the rotating fixture and the holder are brought close to each other while the fixture and the holder are held concentrically, the first jig receives pressure from the second jig which rotates in association with the rotation of the fixture, and rotates the holding shaft about a central axis of the holding shaft;
The machining tool, wherein the machining blade performs a swinging motion relative to the workpiece, with the intersection point as a base point. The machining tool according to claim 1,
When the rotating holder and the fixing device are brought close to each other, the first jig comes into contact with the second jig to stop the rotation of the holding shaft accompanying the rotation of the holder,
The processing tool is characterized in that the processing blade oscillates around the intersection point together with the holding shaft as a result of the rotation of the holder continuing after the holding shaft stops rotating, since the central axis of the holding shaft is inclined relative to the central axis of the holder. The machining tool according to any one of claims 1 to 3,
The machining tool, wherein the first jig has a contact portion capable of making point contact or line contact with the second jig on the plane when the first jig contacts the second jig. The machining tool according to any one of claims 1 to 4 ,
The machining tool is characterized in that the machining blade performs spline machining on the workpiece. A fixture to which the workpiece is attached;
A machining tool for machining the workpiece;
A holder for holding the processing tool;
having
The processing tool is
A processing blade that processes a workpiece by being pressed against the workpiece;
a holder shaft for holding the cutting blade at one end in a direction of a central axis of the holder shaft;
a holder that holds the holder shaft so as to be rotatable about a central axis of the holder shaft;
A first jig provided on the holder shaft;
having
The fixing tool has a second tool that is brought into contact with the first tool when the workpiece is machined,
the holder holds the holder shaft with a central axis of the holder shaft inclined relative to a central axis of the holder itself,
the cutting blade is disposed such that, when the holding shaft is held by the holder, a rotation center at a tip surface of the cutting blade coincides with an intersection point between a central axis of the holder and a central axis of the holding shaft;
the first jig abuts against a second jig provided on the fixing tool on a plane perpendicular to the central axis of the holding shaft and including the intersection point when the fixing tool and the holder are brought close together while rotating either the fixing tool or the holder about their own central axis as the center of rotation, thereby aligning the rotational position of the workpiece with the rotational position of the machining blade in the rotational direction of either the rotating fixing tool or the holder. 7. The machine tool according to claim 6 ,
When the rotating fixture and the holder are brought close to each other while the fixture and the holder are held concentrically, the first jig receives pressure from the second jig which rotates in association with the rotation of the fixture, and rotates the holding shaft about a central axis of the holding shaft;
The machining blade performs a swinging motion relative to the workpiece, using the intersection as a base point. 7. The machine tool according to claim 6 ,
When the rotating holder and the fixing device are brought close to each other, the first jig comes into contact with the second jig to stop the rotation of the holding shaft accompanying the rotation of the holder,
The machine tool is characterized in that the processing blade oscillates together with the holding shaft around the intersection point as a result of the rotation of the holder continuing after the holding shaft stops rotating, since the central axis of the holding shaft is inclined relative to the central axis of the holder. In the machine tool according to any one of claims 6 to 8 ,
The fixture is a chuck having a plurality of gripping jaws,
The machine tool, wherein the second jig is fixed to any one of the plurality of gripping jaws. A workpiece machining method for machining a workpiece attached to a fixture using a machining tool held by a holding fixture, comprising the steps of:
The processing tool is
A processing blade that processes the workpiece by being pressed against the workpiece;
a holder shaft for holding a cutting blade at one end in a direction of a central axis of the holder shaft;
a holder that holds the holder shaft so as to be rotatable about a central axis of the holder shaft;
A first jig provided on the holder shaft;
having
The fixing tool has a second tool that is brought into contact with the first tool when the workpiece is machined,
the holder holds the holder shaft with a central axis of the holder shaft inclined relative to a central axis of the holder itself,
the cutting blade is disposed such that, when the holding shaft is held by the holder, a center of rotation at a tip surface of the cutting blade coincides with an intersection point between a central axis of the holder and a central axis of the holding shaft;
rotating either the fixture or the holder about its own central axis;
a step of bringing the fixture and the holder close to each other and bringing them into contact with a second jig provided on the fixture on a plane that is perpendicular to the central axis of the holding shaft and includes the intersection point, thereby matching a rotational position of the workpiece with a rotational position of the cutting blade in a rotational direction of either the fixture or the holder;
a step of pressing the cutting blade of the processing tool against the workpiece to process the workpiece;
A workpiece machining method comprising: The workpiece machining method according to claim 10 ,
A workpiece machining method, characterized in that the step of machining the workpiece is a step of spline machining a pilot hole provided in the workpiece.

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