JP2014184505A - Gear machining apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gear machining apparatus by which a machining tool and a workpiece are synchronously rotated at a high speed to be capable of performing gear machining by cutting with high machining accuracy.SOLUTION: A controller 100 calculates a shake amount corresponding to a rotational phase angle of a machining tool 42 and a shake amount corresponding to a rotational phase angle of a workpiece W so that a shake amount transferred to a processing surface of the workpiece W is calculated based on these shake amounts. When the shake amount to be transferred is a prescribed threshold value or less, the machining tool 42 and the workpiece W are synchronously rotated at a high speed to be capable of starting a cutting process, thereby improving processing efficiency of a gear with high machining accuracy.

Description

  The present invention relates to a gear processing apparatus that processes a gear by cutting by rotating a processing tool and a workpiece synchronously at high speed.

  When processing a gear by cutting using a machine tool such as a machining center, for example, there is a processing method described in Patent Document 1 as an effective method for processing internal teeth and external teeth. This machining method includes a machining tool that can rotate around a rotation axis, such as a hob 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. Are synchronously rotated at a high speed, and a cutting tool is created by feeding a cutting tool in the direction of the axis of rotation of the workpiece and cutting it.

JP 2012-45687 A

  In the above-described machining method, the machining tool and workpiece are rotated synchronously at high speed for cutting, and therefore the tooth profile of the gear is caused by the shape error of the machining tool and the run-out of the machining tool and workpiece. There is a problem that the accuracy of.

  This invention is made in view of such a situation, and provides the gear processing apparatus which can process a highly accurate gear by cutting by rotating a working tool and a workpiece synchronously at high speed. With the goal.

  (Claim 1) A gear machining apparatus according to the present invention uses a machining tool having a rotation axis inclined with respect to the rotation axis of the workpiece, and rotates the workpiece while rotating the machining tool synchronously with the workpiece. A gear machining apparatus for machining a gear by feeding operation in an axial direction, a tool displacement sensor for detecting a displacement amount in a direction perpendicular to a rotation axis when the machining tool is rotated, and when the workpiece is rotated A workpiece displacement sensor for detecting a displacement amount in a direction perpendicular to the rotation axis of the tool, and a tool deflection amount calculating means for obtaining a deflection amount during rotation of the machining tool based on a detection signal from the tool displacement sensor; A workpiece deflection amount calculating means for obtaining a deflection amount during rotation of the workpiece based on a detection signal from the workpiece displacement sensor, a tool phase angle calculating means for obtaining a rotation phase angle of the machining tool, Rotation phase of the workpiece A workpiece phase angle calculation means for obtaining a relationship, a tool shake calculation means for obtaining a relationship between a rotation phase angle of the machining tool and a deflection amount during rotation, and a rotation phase angle of the workpiece and a deflection amount during rotation. Based on the relationship between the workpiece deflection calculation means for obtaining the relationship, the rotational phase angle and the deflection amount of the machining tool, and the relationship between the rotational phase angle and the deflection amount of the workpiece, transfer to the machining surface of the workpiece A transfer shake amount calculating means for obtaining a shake amount to be performed and determining whether or not the transfer shake amount is equal to or less than a predetermined threshold; and processing for processing the workpiece when the transfer shake amount is equal to or less than the threshold. Control means.

(Claim 2) Further, the gear machining apparatus, when the transfer deflection amount is larger than the threshold value, performs phase correction of the workpiece to correct the phase deviation of the workpiece to reduce the transfer deflection amount. It is good to provide.
(Claim 3) The gear processing device may further include a processing stop unit that stops the processing of the workpiece by the processing tool when the corrected transfer deflection amount is larger than the threshold value.

(Claim 4) Further, the gear machining device includes a tool vibration device for vibrating the machining tool, a workpiece vibration device for vibrating the workpiece, the machining tool, and the work. When at least one of the workpieces does not show a change in the amount of deflection during rotation, it is preferable to include a vibration means that drives at least one of the tool vibration device and the workpiece vibration device.
(Claim 5) Further, the number of tool blades of the machining tool may be an integer or an integral multiple of the number of teeth of the gear to be machined.

  (Claim 1) According to the present invention, since the amount of deflection with respect to the rotational phase angle of the machining tool and the amount of deflection with respect to the rotational phase angle of the workpiece are obtained, the amount of deflection is transferred to the machining surface of the workpiece. The amount of shake can be obtained. Therefore, when the transfer deflection amount is equal to or less than the predetermined threshold value, the machining tool and the workpiece can be directly rotated at high speed to start cutting, so that the machining efficiency of the highly accurate gear can be improved. .

(Claim 2) Since the transfer shake amount is corrected when the transfer shake amount is larger than a predetermined threshold value, the processing efficiency of the highly accurate gear can be further improved.
(Claim 3) When the corrected transfer shake amount is larger than a predetermined threshold value, the processing is stopped, so that the processing defect rate of the gear can be reduced.

  (Claim 4) When at least one of the machining tool and the workpiece does not show a change in the amount of deflection during rotation, the workpiece can be shifted even if the change in the amount of deflection during rotation of the workpiece is shifted in the rotational phase angle direction. The shake amount transferred to the processed surface cannot be corrected. However, the vibration means drives at least one of the tool vibration device and the workpiece vibration device, and vibrates at least one of the machining tool and the workpiece, thereby changing the amount of vibration during rotation. In this state, the amount of shake transferred to the machining surface of the workpiece can be corrected by shifting the change in the amount of shake during rotation of the workpiece in the rotational phase angle direction.

  (Claim 5) If the number of tool blades of the machining tool is an integer multiple of the number of teeth of the gear to be machined, one tooth of the gear to be machined is cut by the same plurality of tool blades. Become. Therefore, since the shape error of the specific plurality of tool blades is transferred to one tooth, the tooth streak error of the tooth can be improved. Further, if the number of tool blades of the machining tool is an integral number of the number of teeth of the gear to be machined, one tooth of the gear to be machined is cut by the same tool blade. . Therefore, since only the shape error of the same tool blade is transferred to one tooth, the tooth streak error of the tooth can be further improved.

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 a flowchart for demonstrating operation | movement of the control apparatus of FIG. It is a figure for demonstrating the tooth trace error which is an error of the tooth profile shape of a gearwheel. It is a graph which shows the tooth trace error with respect to each tooth | gear of the gear by the conventional process. It is a graph which shows the tooth trace error with respect to each tooth of a gear by processing of this embodiment. It is a figure for demonstrating the tooth | gear runout error which is an error of the tooth profile shape of a gearwheel. It is sectional drawing parallel to the axial direction which shows a tool holder. It is the sectional view on the AA line of the tool holder of FIG. 7A. It is a graph which shows the tooth runout error with respect to each tooth | gear of the gearwheel by the process before alignment of the tool holder of FIG. It is a graph which shows the tooth runout error with respect to each tooth | gear of the gearwheel by the process after alignment of the tool holder of FIG. It is a graph which shows the change when the deflection | deviation amount at the time of rotation with respect to the rotation phase angle of a working tool and a workpiece | work, and each deflection amount are synthesize | combined. 10 is a graph showing a change when the amount of deflection of the workpiece in FIG. 9 is calculated as a rotational phase. It is a figure which shows schematic structure and the control apparatus of the gear processing apparatus of another form.

(1. Machine configuration of gear processing device)
As an example of the gear machining apparatus 1, a five-axis machining center will be described as an example and described with reference to FIGS. That is, the gear machining apparatus 1 is an apparatus having three linear 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 rotary spindle 40, a table 50, a tilt table 60, a turn table 70, and a tool displacement. A sensor 80T, a workpiece displacement sensor 80W, a 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 11 a and 11 b on which the column 20 can slide is 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 to 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 and 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 with each other. A pair of Y-axis guide grooves 31 a and 31 b are 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, and the side surface 30 a of the saddle 30 is aligned with 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. The processing tool 42 is a hob having a plurality of tool blades in this embodiment, but other examples include an end mill, a drill, and a tap.

  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) orthogonal 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. A workpiece W is chucked on the turntable 70. The turntable 70 is rotated by the C-axis motor 62 together with the workpiece W.

  The tool displacement sensor 80T is a sensor that detects the amount of displacement in a direction perpendicular to the rotation axis when the machining tool 42 is rotated. The tool displacement sensor 80T includes an arm 81T projecting from the front surface of the saddle 30 in the main shaft direction of the rotary main shaft 40. It is provided at the tip. As the tool displacement sensor 80T, for example, there is a sensor using light or magnetism, and a detection signal is output to the control device 100.

  The workpiece displacement sensor 80 </ b> W is a sensor that detects a displacement amount in a direction perpendicular to the rotation axis of the workpiece W during rotation. Is provided. As the workpiece displacement sensor 80 </ b> W, for example, there is a sensor using light or magnetism, and a detection signal is output to the control device 100.

  The control device 100 controls the spindle motor 41 to rotate the 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, and the workpiece. The workpiece W is cut by moving the W and the machining tool 42 relative to each other in the X-axis direction, the Z-axis direction, the Y-axis direction, the A-axis and the C-axis.

(2. Configuration of control device)
As shown in FIG. 2, the control device 100 includes an X-axis drive control unit 101, a Y-axis drive control unit 102, a Z-axis drive control unit 103, an A-axis drive control unit 104, and a C-axis drive control unit 105. A spindle drive control unit 106, a tool runout amount computing unit 107, a workpiece runout amount computing unit 108, a tool phase angle computing unit 109, a workpiece phase angle computing unit 110, a tool runout computing unit 111, The workpiece shake calculation unit 112, the transfer shake amount calculation unit 113, the workpiece phase indexing unit 114, the machining stop unit 115, the machining control unit 116, and the storage unit 117 are configured. Here, each of the units 101 to 117 can be configured by individual hardware, or can be configured by software.

The X-axis drive control unit 101 is connected to the X-axis motor 11c, and drives and controls the column 20 together with the saddle 30 in the X-axis direction.
The Y-axis drive control unit 102 is connected to the Y-axis motor 23c, and drives and controls the saddle 30 together with the rotary main shaft 40 in the Y-axis direction.
The Z-axis drive control unit 103 is connected to the Z-axis motor 12c and drives and controls the table 50 in the Z-axis direction.

The A-axis drive control unit 104 is connected to the A-axis motor 61 and rotates (swings) the tilt table 60 about the A axis.
The C-axis drive control unit 105 is connected to the C-axis motor 62 and rotates the turntable 70 around the C-axis.
The spindle drive control unit 106 is connected to the spindle motor 41 and rotates the rotary spindle 40.

Based on the detection signal from the tool displacement sensor 80W, the tool runout amount calculation unit 107 calculates a runout amount in a direction perpendicular to the rotation axis when the machining tool 42 is rotated.
The workpiece shake amount calculation unit 108 obtains a shake amount in a direction perpendicular to the rotation axis when the workpiece W is rotated, based on a detection signal from the workpiece displacement sensor 80T.
The tool phase angle calculation unit 109 obtains the rotational phase angle of the machining tool 42 based on the detection signal from the encoder of the spindle motor 41.
The workpiece phase angle calculation unit 110 obtains the rotational phase angle of the workpiece W based on the detection signal from the encoder of the C-axis motor 62.

The tool run-out calculation unit 111 obtains a relationship between the rotational phase angle of the machining tool 42 from the tool phase angle calculation unit 109 and the run-out amount during rotation of the machining tool 42 from the tool run-out calculation unit 107 to obtain a storage unit. 117 is stored.
The workpiece deflection calculation unit 112 obtains and stores the relationship between the rotational phase angle of the workpiece W from the workpiece phase angle calculation unit 110 and the deflection amount during rotation of the workpiece W from the workpiece deflection amount calculation unit 108. Store in the unit 117.

Based on the relationship between the rotational phase angle and the deflection amount of the machining tool 42 read from the storage unit 117 and the relationship between the rotational phase angle and the deflection amount of the workpiece W, the transfer deflection amount calculation unit 113 reads the workpiece W from the storage unit 117. A shake amount transferred to the processing surface is obtained, and it is determined whether or not the transfer shake amount is equal to or less than a predetermined threshold value.
The workpiece phase indexing unit 114 performs phase correction of the workpiece to reduce the transfer shake amount when the transfer shake amount obtained by the transfer shake amount calculation unit 113 is larger than the threshold value.

The machining stop unit 115 stops the machining of the workpiece W by the machining tool 42 when the transfer shake amount corrected by the workpiece phase indexing unit 114 is larger than the threshold value.
The machining control unit 116 rotates the workpiece W and the machining tool 42 synchronously at high speed, sends the machining tool 42 in the direction of the rotation axis of the workpiece W, and creates a tooth by creating an X axis. The drive control unit 101, the Y-axis drive control unit 102, the Z-axis drive control unit 103, the A-axis drive control unit 104, the C-axis drive control unit 105, and the spindle control unit 106 are controlled.

(3. Accuracy of gear tooth profile)
In the gear machining apparatus 1 described above, the machining tool 42 (for example, hob) and the workpiece W are synchronously rotated at a high speed, and the machining tool 42 is sent in the direction of the rotation axis of the workpiece W to cut the teeth. To do. Thus, in order to rotate the machining tool 42 and the workpiece W synchronously, if one tooth of the gear to be created is cut with a plurality of tool blades having different hobbings, different shape errors of each tool blade result in one tooth. It will be transferred to. As a result, the accuracy of the tooth profile, that is, as shown in FIG. 4, is a factor that deteriorates the average value (tooth trace error) of the surface roughness in the axial direction d2 on the side surface s in the circumferential direction d1 of the tooth g of the gear G. .

Therefore, only the shape error of the same tool blade or the plurality of the same tool blades in the processing tool 42 is transferred to one tooth of the gear to be created, so that the tooth streak error is improved. The number of tool teeth of 42 is set to be an integer or an integral multiple of the number of gear teeth to be created.
For example, when the number of tool blades of the machining tool 42 is increased by one from the number of teeth of the gear to be created, as shown in FIG. 5A, the tooth line error e for each tooth g1 to gn (n is the number of teeth) of the gear. Deteriorates in a complicated zigzag shape. On the other hand, when the ratio of the number of tool blades of the machining tool 42 and the number of teeth of the gear to be created is 1: 1, as shown in FIG. 5B, the gear teeth g1 to gn (n is the number of teeth). The tooth trace error e becomes constant (ee) and becomes good because only the shape error of the same tool blade is transferred to one tooth.

  In this way, only the shape error of the same tool blade or the same plurality of tool blades is obtained by setting the number of tool blades of the machining tool 42 to be an integer or an integral multiple of the number of teeth of the gear to be created. Is transferred to one tooth of the gear to be created, and thus the state shown in FIG. 5B is approximated, and the tooth trace error can be improved. However, since the synchronous rotation of the machining tool 42 and the workpiece W is high speed, the machining tool 42 and the workpiece W may be shaken. Further, if there is an error in the attachment of the machining tool 42 and the tool holder 43 or the attachment of the tool holder 43 and the rotary spindle 40, the machining tool 42 will be shaken. As a result, the accuracy of the tooth profile, that is, as shown in FIG. 6, the error between the machining position Pa and the design position Pb at any point on the side surface s in the circumferential direction d1 of the tooth g of the gear G (tooth deviation error f). It becomes a factor to worsen.

  Therefore, the tool displacement sensor 80T and the workpiece displacement sensor 80W detect the amount of deflection of the machining tool 42 and the workpiece W, and the workpiece W is detected based on the detected amount of deflection of the machining tool 42 and workpiece W. The amount of runout transferred to the processed surface is reduced, and the tooth runout error is improved. Note that the reduction in the amount of vibration transferred to the processing surface of the workpiece W can be controlled by the control device 100, which will be described in detail later.

  Further, when it is difficult to reduce the amount of deflection transferred to the machining surface of the workpiece W by the control by the control device 100, as shown in FIGS. 7A and 7B, the rotation axis L of the machining tool 42 is adjusted. A tool holder 43 that can be aligned may be used. The tool holder 43 has an axis (rotational axis) of the taper hole 431 in the vicinity of the insertion hole of the taper hole 431 into which the rear portion of the machining tool 42 is inserted and held, and at 120 ° intervals in the circumferential direction of the taper hole 431. Three screw holes 432 penetrating in a direction perpendicular to L) are provided. Three adjustment screws 433 are screwed into the three screw holes 432. By rotating and adjusting these adjusting screws 433, the rotation axis L of the machining tool 42 inserted and held is tilted to the rotation axis L1, or translated to the rotation axis L2 to obtain the machining tool 42. Can be reduced.

  For example, before the rotation axis L of the machining tool 42 is aligned, as shown in FIG. 8A, the tooth runout error f with respect to each tooth g1 to gn (n is the number of teeth) of the gear becomes a substantially sine curve. Get worse. On the other hand, after alignment of the rotation axis L of the machining tool 42, as shown in FIG. 8B, the tooth runout error f with respect to each tooth g1 to gn (n is the number of teeth) of the gear is the machining tool 42. Since the amount of vibration is reduced, it becomes constant (ff) and becomes good.

(4. Control operation to reduce the amount of deflection transferred to the workpiece surface by the control device)
Next, refer to the flowchart of FIG. 3 for the control operation for reducing the amount of deflection transferred to the machining surface of the workpiece W by the control device 100 when gear processing is performed on the workpiece W by the hob that is the machining tool 42. To explain.

  As shown in FIG. 3, the machining tool 42 held by the tool holder 43 by the automatic tool changer is attached to the rotary spindle 40, and when the operator attaches the workpiece W to the turntable 70 (step S1), the spindle The motor 41 and the C-axis motor 62 are driven to rotate the rotary main shaft 40 and the turntable 70 at high speed (step S2). At this time, the rotational phase angle 0 ° of the rotary spindle 40 (machining tool 42) is aligned with the rotational phase angle 0 ° of the turntable 70 (workpiece W).

  Then, the encoder of the spindle motor 41 starts detecting the rotational phase angle of the rotary spindle 40 (machining tool 42), and the tool displacement sensor 80T displaces in a direction perpendicular to the rotational axis when the machining tool 42 is rotated. Start quantity detection. The encoder of the C-axis motor 62 starts detecting the rotational phase angle of the turntable 70 (workpiece W), and the displacement in the direction perpendicular to the rotational axis when the workpiece W is rotated is detected by the workpiece displacement sensor 80W. Start quantity detection. (Step S3).

  Specifically, the tool phase angle calculation unit 109 obtains the rotational phase angle of the machining tool 42 from the detection signal from the encoder of the spindle motor 41, and the tool runout amount calculation unit 107 obtains the tool phase angle calculation unit 109. The amount of deflection of the machining tool 42 is obtained from the detection signal from the tool displacement sensor 80T in accordance with the rotational phase angle of the machining tool 42. The workpiece phase angle calculation unit 110 obtains the rotational phase angle of the workpiece W from the detection signal from the encoder of the C-axis motor 62, and the workpiece deflection amount calculation unit 108 obtains the workpiece phase angle calculation unit 110. The amount of deflection of the workpiece W is obtained from a detection signal from the workpiece displacement sensor 80W in accordance with the rotational phase angle of the workpiece W.

Next, as shown in FIG. 3, the relationship between the detected displacement amount of the machining tool 42 and the rotational phase angle of the machining tool 42 is obtained, and the detected displacement amount of the workpiece W and the rotational phase of the workpiece W are determined. The relationship with the corner is obtained (step S4).
Specifically, the tool runout calculation unit 111 obtains a change in runout amount during rotation with respect to the rotation phase angle of the machining tool 42 obtained by the tool phase angle computation unit 109 and the tool runout amount computation unit 107 and stores the storage unit 117. The workpiece shake calculation unit 112 obtains a change in the shake amount during rotation with respect to the rotation phase angle of the workpiece W obtained by the workpiece phase angle calculation unit 110 and the workpiece shake amount calculation unit 108, and stores the change amount in the storage unit. 117 is stored.

  For example, as shown by the solid line in FIG. 9, the deflection d during rotation of the machining tool 42 has a rotation phase angle (hereinafter simply referred to as “rotation phase angle”) θ of the machining tool 42 and the workpiece W of 0 °. Between 360 ° and 360 °, the sine wave of one cycle changes between ± dt. That is, when the rotation phase angle θ is 0 ° and 360 °, the deflection d during rotation of the machining tool 42 is the maximum + dt, and when the rotation phase angle θ is 180 °, The shake amount d changes so as to be the minimum −dt.

  Further, as shown by the broken line in FIG. 9, the shake amount d when the workpiece W rotates is changed by a sine wave of three periods between ± dw when the rotation phase angle θ is between 0 ° and 360 °. ing. That is, when the rotational phase angle θ is 0 °, 120 °, 240 °, and 360 °, the deflection d during rotation of the workpiece W is the maximum + dw, and the rotational phase angle θ is 60 °, 180 °, and 300 °. At this time, the shake amount d during rotation of the workpiece W changes so as to be the minimum -dw.

Next, as shown in FIG. 3, based on the change in the amount of deflection during rotation with respect to the rotation phase angle of the machining tool 42 and the change in the amount of deflection during rotation with respect to the rotation phase angle of the workpiece W, The amount of deflection transferred to the W processed surface is obtained (step S5).
Specifically, the transfer shake amount calculation unit 113 changes the change in the shake amount during rotation with respect to the rotation phase angle of the machining tool 42 read from the storage unit 117 and the amount of shake during rotation with respect to the rotation phase angle of the workpiece W. Overlapping the changes, the amount of deflection of the machining tool 42 and the workpiece W with respect to the rotational phase angle of the machining tool 42 is synthesized, and the difference between the maximum value and the minimum value of the combined deflection amount is transferred to the machining surface of the workpiece W Is calculated and stored in the storage unit 117.

  In the above example, as shown by the one-dot chain line in FIG. 9, the combined deflection amount d of the machining tool 42 and the workpiece W is (dt + dw) ˜when the rotational phase angle θ is between 0 ° and 360 °. Between (-dt-dw), it changes with a wave of three periods. That is, when the rotational phase angle θ of the machining tool 42 is 0 ° and 360 °, the combined deflection d of the machining tool 42 and the workpiece W is the maximum (dt + dw), and the rotational phase angle θ of the machining tool 42 is Is 180 °, the combined deflection d of the machining tool 42 and the workpiece W changes so as to be the minimum (−dt−dw). Therefore, the difference (2dt + 2dw) between the maximum value (dt + dw) and the minimum value (−dt−dw) of the combined shake amount d is obtained as the shake amount transferred to the machining surface of the workpiece W.

Next, as shown in FIG. 3, it is determined whether or not the obtained amount of deflection transferred to the machining surface of the workpiece W is larger than a preset threshold value (step S6). When the amount of deflection transferred to the machining surface of the workpiece W is equal to or less than a preset threshold value (step S6: No), gear machining is performed on the workpiece W with the machining tool 42 (step S7). End all processing.
Specifically, the transfer shake amount calculation unit 113 reads the shake amount transferred to the machining surface of the workpiece W stored in the storage unit 117 and its threshold value, and is transferred to the machining surface of the read workpiece W. The amount of shake and the threshold value are compared. When the amount of deflection transferred to the machining surface of the workpiece W is equal to or less than the threshold value, the machining control unit 116 rotates the workpiece W and the machining tool 42 synchronously at high speed, thereby causing the machining tool 42 to rotate. Teeth are created by cutting in the direction of the rotation axis of W.

On the other hand, as shown in FIG. 3, when the deflection amount transferred to the machining surface of the workpiece W is larger than a preset threshold value (step S6: Yes), the machining tool 42 or the workpiece W is rotated. Correction is performed to reduce the shake amount transferred to the machining surface of the workpiece W by performing phase indexing (step S8).
Specifically, the workpiece phase indexing unit 114 shifts the change in the amount of deflection during rotation of the machining tool 42 or the workpiece W in the rotational phase angle direction, and the machining tool 42 and the workpiece with respect to the rotational phase angle. The workpiece is obtained by synthesizing the deflection amount of W and calculating the difference between the maximum value and the minimum value of the synthesized deflection amount, that is, the rotational phase angle of the workpiece W that minimizes the deflection amount transferred to the machining surface of the workpiece W. Correction is performed to reduce the shake amount transferred to the W processed surface.

  In the above example, as shown in FIG. 9, the deflection amount (2dt + 2dw) transferred to the machining surface of the workpiece W is larger than the threshold dr, and therefore, when the workpiece W is rotated as indicated by the broken line in FIG. 9. The change d (θ) of the shake amount is shifted in the direction of the rotational phase angle θ. In this case, as shown by the broken line in FIG. 10, the amount of shake transferred to the machining surface of the workpiece W is minimized by shifting the change in the amount of shake during rotation of the workpiece W by 60 ° in the rotational phase angle direction. The amount of shake is 2 dm (<(2 dt + 2 dw)), and the shake amount reduction correction by the rotational phase indexing of the workpiece W is completed.

Next, as shown in FIG. 3, it is determined whether or not the shake amount transferred to the machined surface of the corrected workpiece W is larger than a threshold value (step S9). When the shake amount transferred to the machined surface of the corrected workpiece W is equal to or less than the threshold value (step S9: No), gear machining is performed on the workpiece W with the machining tool 42 (step S7), and all processing is performed. finish.
In the above example, as shown by the broken line in FIG. 10, the shake amount transferred to the machining surface of the workpiece W is equal to or less than the threshold dr.

On the other hand, as shown in FIG. 3, when the deflection amount transferred to the machining surface of the workpiece W is larger than a preset threshold value (step S9: Yes), an abnormality warning is generated and the gear machining is stopped. (Step S10), and all the processes are terminated.
Specifically, when the processing stop unit 115 determines that the amount of vibration transferred to the processing surface of the workpiece W is larger than the threshold value, the processing stopping unit 115 displays a warning that an abnormality has occurred on the display device, and displays a warning sound. The gear processing is stopped by emitting from an abbreviated speaker.

(5. Effect of reduction control)
Since the amount of vibration with respect to the rotational phase angle of the machining tool 42 and the amount of vibration with respect to the rotational phase angle of the workpiece W are obtained, the amount of vibration transferred to the machining surface of the workpiece W can be obtained from these amounts of vibration. . Therefore, when the transfer deflection amount is equal to or less than the predetermined threshold value, the machining tool and the workpiece can be directly rotated at high speed to start cutting, so that the machining efficiency of the highly accurate gear can be improved. . Further, when the transfer shake amount is larger than the predetermined threshold value, the transfer shake amount is corrected, so that the machining efficiency of the highly accurate gear can be further improved. Further, when the corrected transfer shake amount is larger than a predetermined threshold value, the processing is stopped, so that the processing defect rate of the gear can be reduced.

(6. Different forms)
In the above-described embodiment, the tool displacement sensor 80T and the workpiece displacement sensor 80W detect the deflection amount of the machining tool 42 and the workpiece W, and the detected machining tool 42 and workpiece W are detected based on the deflection amount. The amount of vibration transferred to the work surface of the workpiece W is corrected, or the adjustment screw 433 of the tool holder 43 is adjusted to rotate to correct the amount of vibration transferred to the work surface of the workpiece W. It is not possible to cope with the case where no change in the amount of deflection during rotation is observed in at least one of the machining tool 42 and the workpiece W. In such a case, by providing the following apparatus, it is possible to correct the shake amount transferred to the processed surface of the workpiece W.

  That is, as shown in FIG. 11, the gear machining device 2 includes a tool vibration device 90 </ b> T that vibrates the machining tool 42 built in the rotary spindle 40 in the configuration of the gear machining device 1 shown in FIG. 1, A workpiece vibration device 90W that vibrates the workpiece W built in the turntable 70 is added. The control device 200 is further provided with a vibration exciter 118 that drives the tool vibration device 90T and the workpiece vibration device 90W, respectively, in the configuration of the control device 100 shown in FIG.

  As described above, when at least one of the machining tool 42 and the workpiece W does not change in runout during rotation, even if the change in runout during rotation of the workpiece W is shifted in the rotational phase angle direction, The amount of deflection transferred to the processed surface of the workpiece W cannot be corrected. However, the vibration exciter 118 drives at least one of the tool vibration device 90T and the workpiece vibration device 90W, and vibrates at least one of the machining tool 42 and the workpiece W, thereby rotating the tool during rotation. Since the amount of deflection can be changed, the amount of deflection transferred to the machining surface of the workpiece W is corrected by shifting the variation of the amount of deflection during rotation of the workpiece W in the rotational phase angle direction in this state. can do.

  In the above-described embodiment, 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 that allows the tool 42 to 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. Further, although the processing of the external gear has been described, the present invention can be similarly applied to the processing of the internal gear.

1: gear processing device, 80T: tool displacement sensor, 80W: workpiece displacement sensor, 90T: tool vibration device, 90W: workpiece vibration device 100: control device, 107: tool deflection amount calculation unit, 108: Workpiece deflection amount calculation unit 109: Tool phase angle calculation unit 110: Workpiece phase angle calculation unit 111: Tool deflection calculation unit 112: Workpiece deflection calculation unit 113: Transfer deflection amount calculation unit 114 : Workpiece phase indexing unit, 115: Machining stop unit, 116: Machining control unit, 117: Storage unit, 118: Excitation unit, W: Workpiece

Claims (5)

Gear machining that uses a machining tool having a rotation axis inclined with respect to the rotation axis of the workpiece and feeds the machining tool in the direction of the rotation axis of the workpiece while rotating the machining tool synchronously with the workpiece to process the gear. A device,
A displacement sensor for a tool for detecting a displacement amount in a direction perpendicular to a rotation axis during rotation of the machining tool;
A displacement sensor for a workpiece for detecting a displacement amount in a direction perpendicular to the rotation axis during rotation of the workpiece;
A tool runout amount calculating means for obtaining a runout amount during rotation of the machining tool based on a detection signal from the tool displacement sensor;
A workpiece deflection amount calculating means for obtaining a deflection amount during rotation of the workpiece based on a detection signal from the workpiece displacement sensor;
Tool phase angle calculation means for obtaining a rotation phase angle of the machining tool;
A workpiece phase angle calculating means for obtaining a rotational phase angle of the workpiece;
Tool runout calculating means for obtaining a relationship between the rotational phase angle of the machining tool and the runout amount during rotation;
A workpiece shake calculation means for obtaining a relationship between a rotational phase angle of the workpiece and a shake amount during rotation;
Based on the relationship between the rotational phase angle and the amount of deflection of the machining tool and the relationship between the rotational phase angle of the workpiece and the amount of deflection, the amount of deflection transferred to the work surface of the workpiece is obtained, and the amount of transfer deflection Transfer shake amount calculating means for determining whether or not is equal to or less than a predetermined threshold;
A gear processing apparatus comprising: a processing control unit configured to process the workpiece when the transfer deflection amount is equal to or less than the threshold value. The gear machining device includes:
The gear machining apparatus according to claim 1, further comprising: a workpiece phase indexing unit that performs phase indexing of the workpiece to correct the transfer deflection amount when the transfer deflection amount is larger than the threshold value. The gear machining device includes:
The gear machining apparatus according to claim 2, further comprising a machining stop unit that stops the machining of the workpiece by the machining tool when the corrected transfer deflection amount is larger than the threshold value. The gear machining device includes:
A tool vibration device for vibrating the machining tool;
A vibration exciter for a workpiece for vibrating the workpiece;
When at least one of the machining tool and the workpiece does not show a change in runout amount during rotation, an excitation unit that drives at least one of the tool excitation device and the workpiece excitation device; A gear machining apparatus according to claim 2 or 3, comprising:   The gear machining apparatus according to any one of claims 1 to 4, wherein the number of tool blades of the machining tool is one or an integral multiple of an integer number of teeth of a gear to be machined.

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