JP6427897B2 - Gear processing equipment - Google Patents

Description

  The present invention relates to a gear machining apparatus for machining a gear by machining by rotating a working tool and a workpiece synchronously at high speed.

  As an effective method of processing the internal teeth and external teeth by cutting using a machine tool such as a machining center, there is a processing method described in Patent Document 1, for example. This machining method includes a machining tool that can rotate around a rotation axis, for example, a cutter having a plurality of tool blades, and a workpiece that can rotate around a rotation axis inclined at a predetermined angle with respect to the rotation axis of the machining tool. This is a machining method in which teeth are created by rotating a workpiece synchronously at high speed and sending a machining tool in the direction of the axis of rotation of the workpiece for cutting.

  Generally, chips generated by cutting are removed from the tool blade by the pressure of coolant discharged from the inside of the processing tool toward the tool blade (see, for example, Patent Documents 2 and 3).

JP 2012-45687 A JP 2012-232406 A US Patent Application Publication No. 2009/0226268

  In the machining method described in Patent Document 1 described above, a machining tool in which a tool blade is formed on a tool end surface is used. Therefore, especially in the case of internal teeth machining, chips generated by cutting tend to accumulate inside the workpiece, etc., and if it enters between the tool blade of the machining tool and the workpiece during cutting, it will bite. There is a possibility that chatter vibration may occur due to the insertion, and the processing accuracy may deteriorate.

  The present invention has been made in view of such circumstances, and a gear capable of removing chips generated when machining a gear by machining using a machining tool having a tool blade formed on a tool end face from the tool blade. An object is to provide a processing apparatus.

(Claim 1) The gear machining apparatus of the present invention uses a machining tool having a rotation axis inclined with respect to the rotation axis of the workpiece, and rotates the machining tool synchronously with the workpiece. A gear machining apparatus for machining a gear by relatively feeding in a rotation axis direction of an object, wherein the machining tool is a tool for machining internal teeth of the workpiece, and the tool of the machining tool The blade is formed in a shape corresponding to the teeth of the gear, and a discharge hole capable of discharging a fluid in a direction toward the tool blade is provided on the center side of the end surface of the processing tool. The fluid moves from the machining position of the workpiece by the tool blade to the feed advance direction side relative to the workpiece of the machining tool, and the gear machining apparatus holds the workpiece in position. Cylindrical workpiece holder that can be rotated The workpiece holder is provided with the cylindrical inner circumference at a position on the far side in the advancing direction from the end surface of the workpiece on the advancing direction side relative to the workpiece of the machining tool. discharging holes for discharging the fluid communication between the surface and the outer circumferential surface that is provided.

As a result, chips generated by cutting at the tool blade of the machining tool are blown off from the tool blade to the workpiece in the feed advance direction by the pressure of the fluid discharged from the discharge hole. Removed. Therefore, the chips generated by the cutting process are difficult to enter between the tool blade and the workpiece during the cutting process, so that the generation of chatter vibration due to the biting can be suppressed and the processing accuracy can be improved. Then, the chips that are blown off in the feed advance direction relative to the workpiece of the machining tool are discharged together with the fluid through the discharge hole of the workpiece holder to the outside of the workpiece holder. Therefore, chips generated by cutting do not accumulate inside the workpiece or workpiece holder, and do not enter between the tool blade and workpiece during cutting. It is possible to improve the machining accuracy by preventing the occurrence of chatter vibration.

(Claim 2 ) The discharge hole is formed by an inclined surface provided at a predetermined interval in a circumferential direction of the workpiece holder, and a normal line of the inclined surface is a diameter of the workpiece holder. It is good to have the component which faces a direction inner side, and the component which faces a counter rotation direction side.
As a result, when the workpiece holder rotates, the air in the workpiece holder hits the inclined surface from the center in the workpiece holder, passes through the discharge hole, and spirals outside the workpiece holder. Therefore, the chips accumulated in the workpiece holder are pushed by the spiral airflow together with the fluid and discharged from the discharge hole to the outside of the workpiece holder.

(Claim 3 ) It is preferable that the discharge hole of the machining tool is provided so that the fluid can be discharged in parallel to the rake face of the tool blade.
Thereby, since the fluid discharged from each discharge hole can suppress the loss of the kinetic energy by the collision with the rake face, the chips generated by the cutting process in the tool blade can be efficiently blown off.

(Claim 4 ) It is preferable that the number of discharge holes of the machining tool is smaller than the number of the tool blades.
As a result, the fluid discharged from each discharge hole is discharged at a higher pressure than when the discharge holes are provided in the same number or as many as the tool blades. The machining tool can be reliably ejected and removed in the direction of feed relative to the workpiece.

(Claim 5 ) It is preferable that the discharge hole of the machining tool is provided at a predetermined distance from the tool blade.
As a result, the fluid discharged from each discharge hole is diffused to reach the tool blades and sprayed onto all the tool blades, so that chips generated by the cutting process can be reliably removed at all the tool blades. it can.

1 is a perspective view showing an overall configuration of a gear machining apparatus according to an embodiment of the present invention. It is a figure which shows schematic structure and the control apparatus of the gear processing apparatus of FIG. It is sectional drawing which looked at schematic structure of the tool for processing in the diameter direction. It is the figure which looked at schematic structure of the processing tool of FIG. 3 from the tool blade side to the axial direction. It is sectional drawing which looked at schematic structure of the workpiece holder in radial direction. It is the figure which looked at schematic structure of the 1st holder of the workpiece holder in the radial direction. It is the figure which looked at schematic structure of the 1st holder of FIG. 6 in the axial direction. It is the figure which looked at schematic structure of the 2nd holder of the workpiece holder in the radial direction. It is the figure which looked at schematic structure of the 2nd holder of FIG. 8 in the axial direction. It is the figure which looked at schematic structure of the 3rd holder of the workpiece holder in the radial direction. It is the figure which looked at schematic structure of the 3rd holder of FIG. 10 in the axial direction. It is a figure which shows the time change of the load applied to a workpiece during the conventional cutting process. It is a figure which shows the time change of the load applied to a workpiece during the cutting process of this embodiment.

(Mechanical configuration of gear processing equipment)
In the present embodiment, a five-axis machining center will be described as an example of the gear machining apparatus 1 and will be described with reference to FIGS. 1 and 2. That is, the gear machining apparatus 1 is an apparatus having three rectilinear axes (X, Y, Z axes) and two rotation axes (A axis, C axis) orthogonal to each other as drive axes.

  As shown in FIGS. 1 and 2, the gear machining apparatus 1 includes a bed 10, a column 20, a saddle 30, a rotation spindle 40, a table 50, a tilt table 60, a turntable 70, and a workpiece. The holder 80, the control device 100, and the like are included. Although not shown, a known automatic tool changer is provided along with the bed 10.

  The bed 10 has a substantially rectangular shape and is disposed on the floor. However, the shape of the bed 10 is not limited to a rectangular shape. On the upper surface of the bed 10, a pair of X-axis guide rails 11a and 11b on which the column 20 is slidable are formed in parallel to each other so as to extend in the X-axis direction (horizontal direction). Further, the bed 10 is provided with an unillustrated X-axis ball screw for driving the column 20 in the X-axis direction between the pair of X-axis guide rails 11a and 11b. The X-axis ball screw is rotated. A driving X-axis motor 11c is disposed.

  A pair of X-axis guide grooves 21a and 21b are formed on the bottom surface of the column 20 so as to extend in the X-axis direction and in parallel with each other. In the column 20, a pair of X-axis guide grooves 21a and 21b are fitted on the pair of X-axis guide rails 11a and 11b via ball guides 22a and 22b so that the column 20 can move in the X-axis direction with respect to the bed 10. The bottom surface of the column 20 is in close contact with the top surface of the bed 10.

  Further, on a side surface (sliding surface) 20a parallel to the X axis of the column 20, a pair of Y axis guide rails 23a, 23b on which the saddle 30 can slide extends in the Y axis direction (vertical direction), and Are formed parallel to each other. Further, the column 20 is provided with a Y-axis ball screw (not shown) for driving the saddle 30 in the Y-axis direction between the pair of Y-axis guide rails 23a and 23b. The Y-axis ball screw is rotated. A Y-axis motor 23c to be driven is disposed.

  A pair of Y-axis guide grooves 31a and 31b are formed on the side surface 30a of the saddle 30 facing the sliding surface 20a of the column 20 so as to extend in the Y-axis direction and in parallel to each other. The saddle 30 has a pair of Y-axis guide grooves 31 a and 31 b fitted into the pair of Y-axis guide rails 23 a and 23 b so that the saddle 30 can move in the Y-axis direction with respect to the column 20. Are closely in contact with the sliding surface 20a.

  The rotating spindle 40 is rotatably provided by a spindle motor 41 accommodated in the saddle 30 and supports a machining tool 42. The machining tool 42 is held by the tool holder 43 and fixed to the tip of the rotation main shaft 40, and rotates with the rotation of the rotation main shaft 40. Further, the machining tool 42 moves in the X axis direction and the Y axis direction with respect to the bed 10 as the column 20 and the saddle 30 move. Details of the machining tool 42 will be described later.

  Further, on the upper surface of the bed 10, a pair of Z-axis guide rails 12 a and 12 b on which the table 50 can slide extend in the Z-axis direction (horizontal direction) perpendicular to the X-axis direction and are parallel to each other. Is formed. Further, the bed 10 is provided with an unillustrated Z-axis ball screw for driving the table 50 in the Z-axis direction between the pair of Z-axis guide rails 12a and 12b. The Z-axis ball screw is rotated. A Z-axis motor 12c to be driven is disposed.

  The table 50 is provided on the pair of Z-axis guide rails 12 a and 12 b so as to be movable in the Z-axis direction with respect to the bed 10. A tilt table support portion 63 that supports the tilt table 60 is provided on the upper surface of the table 50. The tilt table support portion 63 is provided with a tilt table 60 that can rotate (swing) about the A axis in the horizontal direction. The tilt table 60 is rotated (swinged) by an A-axis motor 61 housed in the table 50.

  The tilt table 60 is provided with a turntable 70 so as to be rotatable around a C axis perpendicular to the A axis. The turntable 70 is provided with a workpiece holder 80 that holds the workpiece W. The turntable 70 is rotated by the C-axis motor 62 together with the workpiece W and the workpiece holder 80. The details of the workpiece holder 80 will be described later.

  The control device 100 controls the spindle motor 41 to rotate the machining tool 42 and controls the X-axis motor 11c, the Z-axis motor 12c, the Y-axis motor 23c, the A-axis motor 61, and the C-axis motor 62, The workpiece W is cut by relatively moving the workpiece W and the machining tool 42 in the X axis direction, the Z axis direction, the Y axis direction, the A axis direction, and the C axis direction.

(Machining tool)
In the gear machining apparatus 1 described above, the machining tool 42 and the workpiece W are rotated synchronously at high speed, and the machining tool 42 is sent in the direction of the rotation axis of the workpiece W to create a tooth. . The tool blade 42a of the machining tool 42 is formed in the same shape as the teeth that mesh with the gear to be machined. In this cutting process, a machining tool 42 in which a tool edge 42a is formed on the tool end face is used. Chips generated by the cutting process are easily accumulated inside the workpiece W or the like, and the tool is cut during the cutting process. If it enters between the blade 42a and the workpiece W, chatter vibration may occur due to biting as shown in part A of FIG.

  Therefore, as shown in FIGS. 3 and 4, a discharge hole 94 that discharges coolant (corresponding to “fluid” of the present invention) in the direction U toward the tool blade 42 a is provided in the center of the end face of the machining tool 42. Is provided. As a result, as shown in FIG. 5, the coolant discharged from the discharge holes 94 is moved relative to the workpiece W of the machining tool 42 from the machining position of the workpiece W by the tool blade 42a. Move to the side. Therefore, the chips generated by the cutting process in the tool blade 42a of the processing tool 42 are fed relative to the workpiece W of the processing tool 42 from the tool blade 42a by the pressure of the coolant discharged from the discharge hole 94. It is blown off to the V side and removed, and finally, as indicated by arrows S and T in FIG. 5, the discharge hole 87 of the first holder 81 to the discharge hole of the third holder 83 of the workpiece holder 80. It is discharged to the outside of the workpiece holder 80 through 88. Therefore, the chips generated by the cutting process do not accumulate inside the workpiece W or the workpiece holder 80, and do not enter between the tool blade 42a and the workpiece W during the cutting process. Therefore, as shown in part A of FIG. 13, chatter vibration due to biting can be prevented and machining accuracy can be improved.

Specifically, the machining tool 42 is provided with a bolt hole 42 b penetrating in the rotation axis direction, and the machining tool 42 uses the male thread portion 91 of the bolt 90 passing through the bolt hole 42 b at the tip of the tool holder 43. It is fastened and fixed by screwing into the provided female screw portion 44.
The tool holder 43 is provided with a hole 45 extending from the female thread portion 44 to the rear end of the tool holder 43 in the axial direction of the machining tool 42. The bolt 90 is provided with a hole 93 extending in the axial direction of the machining tool 42 from the tip of the male screw portion 91 to the middle of the head 92, and further from the tip of the hole 93 on the head 92 side to the head 92. Eight discharge holes 94 extending radially at equal angular intervals in the radial direction of the machining tool 42 to the outer periphery are formed.

  As a result, the discharge hole 94, the hole 93, and the hole 45 communicate with each other. Therefore, by communicating the hole 45 with the coolant supply path, the coolant is supplied as shown by an arrow U in FIGS. Each discharge hole 94 can be discharged toward the tool blade 42a in the direction of the tool blade 42a. Therefore, chips generated by cutting at the tool blade 42a of the machining tool 42 are ejected and removed from the tool blade 42a toward the workpiece W of the machining tool 42 relative to the workpiece W by the pressure of the coolant. Is done. The coolant pressure at this time is preferably 2 MPa or more.

  Moreover, since each discharge hole 94 is provided so as to be parallel to the rake face 42c of the machining tool 42, the coolant is discharged from each discharge hole 94 in the direction of the tool blade 42a substantially parallel to the rake face 42c. be able to. Therefore, since the coolant discharged from each discharge hole 94 can minimize the loss of kinetic energy due to the collision with the rake face 42c, the chips generated by the cutting process at the tool blade 42a can be efficiently blown off. . However, if each discharge hole 94 is too far forward in the axial direction with respect to the rake face 42c, the coolant may not be sprayed onto the tool blade 42a. Therefore, each discharge hole is 5 mm forward in the axial direction with respect to the rake face 42c. It is desirable to provide within.

  In addition, since the discharge holes 94 are provided in a smaller number than the tool blades 42a of the processing tool 42, the coolant can be supplied at a higher pressure than in the case where the discharge holes 94 are provided in the same number or more than the tool blades 42a. Can be discharged. Therefore, the chips generated by the cutting process at the tool blade 42a of the processing tool 42 are reliably blown off and removed in the feed traveling direction V side relative to the workpiece W of the processing tool 42.

  Further, since each discharge hole 94 is provided so as to be separated from the tool blade 42a of the machining tool 42 by a predetermined distance, all the coolant discharged from each discharge hole 94 is diffused to reach the tool blade 42a. Can be sprayed onto the tool blade 42a. Therefore, the chips generated by the cutting process are surely removed by all the tool blades 42a.

  The workpiece holder 80 is a jig for holding a hollow cylindrical workpiece W whose inner teeth are cut. As shown in FIG. 5, the workpiece holder 80 includes a first holder 81, a second holder 82 disposed so as to sandwich the workpiece W in the axial direction with respect to the first holder 81, The third holder 83 is arranged on the outer side in the radial direction with respect to the first holder 81.

  The first holder 81 accumulates chips generated when the workpiece W is machined by cutting, inside the first holder 81 and discharges the chips from the inside of the first holder 81 to the third holder 83 side. It is a jig for. The third holder 83 is a jig for discharging chips discharged from the inside of the first holder 81 to the outside of the third holder 83. The first holder 81 and the second holder 82 are also jigs for positioning and holding the workpiece W with respect to the turntable 70 in the axial direction. The third holder 83 is also a jig for positioning (centering) the workpiece W with respect to the turntable 70 in the radial direction.

  As shown in FIGS. 5, 6, and 7, the first holder 81 has a cylindrical base 84 that is slightly larger than the outer diameter of the workpiece W, and a diameter that is slightly smaller than the outer diameter of the workpiece W. A triangular prism-shaped fan having a ring-shaped top plate 85 arranged coaxially with the pedestal 84, and eight inclined surfaces 86a sandwiched and fixed between the right end surface 84r of the pedestal 84 and the left end surface 85l of the top plate 85. 86.

  The pedestal 84 is coaxial with the turntable 70, has a left end face 84l in close contact with the table surface 70a of the turntable 70, and is fastened and fixed to the turntable 70 with bolts or the like. As shown in FIG. 5, the eight fans 86 have a normal line X of each inclined surface 86 a having a component Xd facing the radial inner side of the first holder 81 and a component Xq facing the counter rotation direction Q side. Along the outer peripheral edges of the right end surface 84r of the pedestal 84 and the left end surface 85l of the top plate 85, they are arranged and fixed with a gap of an equal angle (45 degrees). The eight gaps between the fans 86 function as discharge holes 87 for discharging chips and coolant generated when the workpiece W is processed by cutting. The left end surface Wl of the workpiece W is in close contact with the right end surface 85r of the top plate 85.

  Accordingly, as indicated by an arrow S in FIGS. 6 and 7, when the first holder 81 rotates in the R direction, the air between the pedestal 84 and the top plate 85 flows from the center of the first holder 81. Since it hits the inclined surface 86a of the fan 86 and flows out to the outside of the first holder 81 through each discharge hole 87, the chips accumulated between the pedestal 84 and the top plate 85 are spirally formed together with the coolant. It is pushed by the air current and discharged from the discharge holes 87 to the third holder 83 side.

As shown in FIGS. 5, 8, and 9, the second holder 82 is formed in a ring shape larger in diameter than the outer diameter of the workpiece W, and is slightly closer to the one end surface than the outer diameter of the workpiece W. A large-diameter ring-shaped recess 82a is formed. The second holder 82 is fastened and fixed to the right end surface 83r of the third holder 83 with a bolt or the like in a state where the right end surface Wr of the workpiece W is in close contact with the bottom surface 82b of the recess 82a.
As a result, the workpiece W is sandwiched and fixed between the right end surface 85r of the top plate 85 of the first holder 81 and the bottom surface 82b of the recess 82a of the second holder 82, so the axial direction relative to the turntable 70 The position is positioned.

As shown in FIGS. 5, 10, and 11, the third holder 83 is formed in a hollow cylindrical shape having a slightly larger diameter than the outer diameter of the first holder 81. The third holder 83 is coaxial with the turntable 70, has a left end face 83l in close contact with the table surface 70a of the turntable 70, and is fastened and fixed to the turntable 70 with bolts or the like. Eight discharge holes 88 are formed in the peripheral wall of the third holder 83 at positions corresponding to the discharge holes 87 of the first holder 81.
10 and FIG. 11, when the third holder 83 rotates together with the first holder 81, the chips discharged from the discharge hole 87 of the first holder 81 are retained in the third holder. It is discharged to the outside of the third holding tool 83 through the discharge hole 88 of the tool 83.

In addition, on the peripheral wall of the third holder 83, the workpiece W is sandwiched and fixed between the right end surface 85 r of the top plate 85 of the first holder 81 and the bottom surface 82 b of the recess 82 a of the second holder 82. Four female screw holes 83a are drilled at corresponding positions. Bolts 89 are screwed into the female screw holes 83a.
As a result, the workpiece W is pushed by the bolt 89 and can move in the radial direction, so that the radial position with respect to the turntable 70 is positioned (centered).

(Other)
In the embodiment described above, the workpiece holder 80 is configured to be fastened and fixed to the turntable 70 with a bolt or the like. However, the workpiece holder 80 may be configured to be gripped by a chuck, in which case the discharge hole 87 of the first holder 81 is used. Alternatively, the position where the discharge hole 88 of the third holder 83 is avoided is gripped. Further, the number of the gaps 87 of the first holder 81 and the discharge holes 88 of the third holder 83 is not limited to eight, and may be an arbitrary number. Further, the fan 86 of the first holding tool 81 is not limited to the triangular prism shape, but may have a shape provided with an inclined surface 86a inclined at an acute angle θ with respect to the rotation direction R of the first holding tool 81. For example, a plate shape may be used.

  Further, the discharge hole 94 of the machining tool 42 is formed so as to extend radially from the tip of the hole 93 on the head 92 side of the bolt 90 to the outer periphery of the head 92 in the radial direction of the machining tool 42 to scoop the coolant. Although it is configured to discharge in parallel to the surface 42c, only the hole extending in the axial direction of the machining tool 42 is formed from the tip of the male thread portion 91 to the tip of the head 92 without forming the discharge hole 94, and the machining tool It is good also as a structure which discharges a coolant along the rake face 42c with the centrifugal force by rotation of 42. FIG. Further, the number of the discharge holes 94 is not limited to eight as long as it is smaller than the tool blade 42a of the machining tool 42.

  Further, although the processing of the internal gear has been described, the present invention can be similarly applied to the processing of the external gear. In addition, the gear machining apparatus 1 that is a 5-axis machining center is configured to allow the workpiece W to turn on the A axis. On the other hand, the 5-axis machining center may be configured as a vertical machining center so that the machining tool 42 can turn on the A axis. Further, although the case where the present invention is applied to a machining center has been described, the present invention can be similarly applied to a dedicated gear machining machine.

  1: gear processing device, 42: machining tool, 42a: tool blade, 80: workpiece holder, 81: first holder, 82: second holder, 83: third holder, 86: fan, 86a: Inclined surface, 87, 88: Discharge hole, 94: Discharge hole, W: Workpiece

Claims (5)

Using a machining tool having a rotation axis that is inclined with respect to the rotation axis of the workpiece, while performing the synchronous rotation of the machining tool with the workpiece, the feed operation is relatively performed in the rotation axis direction of the workpiece. A gear machining apparatus for machining gears,
The processing tool is a tool for processing internal teeth of the workpiece, and the tool blade of the processing tool is formed in a shape corresponding to the gear teeth,
On the center side of the end face of the processing tool, a discharge hole is provided that can discharge fluid in a direction toward the tool blade,
The discharged fluid moves from the machining position of the workpiece by the tool blade to the side of the feed advance direction relative to the workpiece of the machining tool ,
The gear machining apparatus includes a cylindrical workpiece holder that can rotate by positioning and holding the workpiece,
The workpiece holder includes the cylindrical inner peripheral surface at a position on the far side in the traveling direction from the end surface of the workpiece on the traveling direction side relative to the workpiece of the processing tool. discharging holes for discharging the fluid that provided the outer peripheral surface in communication, the gear machining apparatus. The discharge hole is formed by an inclined surface provided at a predetermined interval in a circumferential direction of the workpiece holder, and a component in which a normal line of the inclined surface faces a radially inner side of the workpiece holder The gear machining apparatus according to claim 1 , wherein the gear machining apparatus has a component facing the counter-rotation direction. The discharge hole of the processing tool, the fluid is provided so as to be parallel to the discharge and the rake face of the tool blade, the gear machining apparatus of any one of claims 1 or 2. The discharge hole of the processing tool, the provided so as to be fewer than the number of tool blades, any one of the gear machining apparatus according to claim 1-3. The gear machining apparatus according to any one of claims 1 to 4 , wherein a discharge hole of the machining tool is provided at a predetermined distance from the tool blade.

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