JP2010266362A - Rotational position detector and laser processing machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To detect the rotational position of a rotating shaft having a rotation stroke of 360° or larger only by using signals from a sensor for detecting the presence or absence of a dog. <P>SOLUTION: When an origin sensor 16c has detected a dog 20c and neither an OT+sensor 16a nor an OT-sensor 16b has detected a dog 20a or a dog 20b, it is determined that a processing head 13 is at an origin position. When the origin sensor 16c has detected the dog 20c, the OT-sensor 16b has not detected the dog 20b, and the OT+sensor 16a has detected the dog 20a, it is determined that the processing head 13 has been rotated by +360°. When the origin sensor 16c has detected the dog 20c, the OT+sensor 16a has not detected the dog 20a, and the OT-sensor 16b has detected the dog 20b, it is determined that the processing head 13 has been rotated by -360°. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a rotational position detection device and a laser beam machine, and more particularly, to a method for detecting a rotational position of a rotational shaft where overtravel occurs.

  With a rotating shaft having a rotation stroke of 360 ° or more, when the rotating shaft is rotated by 360 °, it returns to the original position. Therefore, simply determining whether the origin sensor is on or off based on the presence or absence of a dog, Cannot determine if it has rotated. For this reason, there is a method of determining how many times the rotation shaft has rotated by converting the rotation motion of the rotation shaft into a linear motion via a ball screw and determining whether the proximity sensor is turned on or off by the linear motion. .

  Further, in Patent Document 1, when the rotation axis is rotated in the CW or CCW direction depending on the state of the dog and the sensor for detecting the presence or absence of the dog, the rotation axis is CCW when the positional relationship between the dog and the sensor is the same. By using the fact that the number of pulses of the encoder attached to the drive source is different in control, the origin can be detected at all rotation angle positions even when the rotation operation range of the rotation shaft is 360 ° or more. A technique that enables this is disclosed.

JP-A-8-313298

  However, the method for converting the rotational motion into the linear motion requires a linear motion conversion component such as a ball screw or a spur gear. For this reason, there has been a problem that the cost is increased, and it takes time and effort to assemble and adjust, and a failure is likely to occur due to deterioration and damage of the linear motion conversion component.

  Further, the method disclosed in Patent Document 1 has a problem in that it is necessary to count the number of pulses of an encoder attached to a drive source, and parts such as an encoder, a counter, and a comparator are separately required.

  The present invention has been made in view of the above, and by using only a signal from a sensor for detecting the presence or absence of a dog without converting rotational motion into linear motion, rotation of 360 ° or more It is an object of the present invention to obtain a rotational position detection device and a laser processing machine capable of detecting the rotational position of a rotational shaft having a stroke.

  In order to solve the above-described problems and achieve the object, the rotational position detection device of the present invention includes a first rotating body that rotates in synchronization with a rotating shaft, and the rotation of the first rotating body. A second rotating body that rotates at a non-integer multiple of the rotating period of the first rotating body, and has a smaller rotating period than the first rotating body; and a first dog provided on the first rotating body; A second dog provided on the second rotating body, an origin sensor for detecting the first dog each time the first rotating body rotates by 360 ° from the origin position, and the first dog An OT + sensor arranged so that the second dog is detected when the rotating body rotates by +360 N ° (N is a positive integer) from the origin position, and the first rotating body is − from the origin position. An OT-sensor arranged so that the second dog is detected when rotated by 360 N °. When the first dog is detected by the origin sensor and the second dog is not detected by the OT + sensor and the OT− sensor, the first rotating body is at the origin position. The first dog is detected by the origin sensor, and the second dog is detected by the OT + sensor without the second dog being detected by the OT− sensor. The first rotating body is rotated by +360 N °, the first dog is detected by the origin sensor, and the second dog is not detected by the OT + sensor. And a rotational position determining unit that determines that the first rotating body has rotated by −360 N ° when the second dog is detected by the OT-sensor.

  According to the present invention, the rotational position of the rotary shaft having a rotational stroke of 360 ° or more can be obtained by using only the signal from the sensor for detecting the presence or absence of the dog without converting the rotational motion into the linear motion. There is an effect that it can be detected.

FIG. 1 is a perspective view showing a schematic configuration of a laser beam machine to which Embodiment 1 of the rotational position detection device according to the present invention is applied. FIG. 2 is a block diagram showing a schematic configuration of the laser beam machine shown in FIG. FIG. 3A is a cross-sectional view showing a schematic configuration of a machining head to which the first embodiment of the rotational position detection device according to the present invention is applied. FIG. 3-2 is an arrow view showing a schematic configuration of the machining head viewed from the E1 direction of FIG. 3-1. FIG. 4 is a diagram illustrating detection positions of the dogs 20a, 20b, and 20c detected by the OT + sensor 16a, the OT− sensor 16b, and the origin sensor 16c of FIG. 3-2, respectively. FIG. 5A is a cross-sectional view showing a schematic configuration of a machining head to which the second embodiment of the rotational position detection device according to the present invention is applied. FIG. 5-2 is an arrow view showing a schematic configuration of the machining head viewed from the E2 direction of FIG. FIG. 6 is a diagram illustrating detection positions of the dogs 30a, 30b, 30c, and 30d detected by the OT + sensor 26a, the OT− sensor 26b, and the origin sensor 26c in FIG. FIG. 7-1 is a cross-sectional view showing a schematic configuration of a machining head to which Embodiment 3 of the rotational position detection device according to the present invention is applied. FIG. 7-2 is an arrow view showing a schematic configuration of the machining head viewed from the E3 direction of FIG. FIG. 8 is a diagram illustrating detection positions of the dogs 40a and 40c detected by the OT + sensor 36a, the OT− sensor 36b, and the origin sensor 36c of FIG. 7-2, respectively.

  Embodiments of a rotational position detection device according to the present invention will be described below in detail with reference to the drawings. Note that the present invention is not limited to the embodiments.

Embodiment 1 FIG.
FIG. 1 is a perspective view showing a schematic configuration of a laser beam machine to which Embodiment 1 of the rotational position detection device according to the present invention is applied, and FIG. 2 is a block diagram showing a schematic configuration of the laser beam machine of FIG. is there. 1 and 2, the laser beam machine emits laser light generated by a machine body 11 that supports a machining head 13, an NC control unit 12 that performs NC control, and a laser oscillator 15 to a workpiece K. There are provided a machining head 13 that performs, a servo motor 14 that generates a driving force for rotating the machining head 13 in the W direction, and a laser oscillator 15 that generates laser light.

  Here, the processing machine main body 11 is provided with a table 10 on which the workpiece K is placed, and the table 10 is supported so as to be movable in the X direction. The processing head 13 is supported by the processing machine main body 11 so as to be movable in the YZ direction, and is configured to be rotatable in the UW direction.

  Further, the laser processing machine includes an origin sensor 16c that detects the origin position of the machining head 13, an OT + sensor 16a that detects a position where the machining head 13 is rotated by + 360 °, and a position where the machining head 13 is rotated by −360 °. An OT-sensor 16b for detection is provided.

  Further, the NC control unit 12 determines the rotational position of the machining head 13 based on signals from the origin sensor 16c, the OT + sensor 16a, and the OT− sensor 16b, and the determination by the rotational position determination unit 12a. Based on the result, a motor drive control unit 12b that performs drive control of the servo motor 14 is provided.

  3A is a cross-sectional view illustrating a schematic configuration of a machining head to which the first embodiment of the rotational position detection device according to the present invention is applied, and FIG. 3B is a machining view as viewed from the E1 direction in FIG. It is an arrow view which shows schematic structure of a head. 3A and 3B, a small pulley 17a is connected to the drive shaft of the servo motor 14 via a speed reducer 18, and a large pulley 17b is connected to the rotating shaft of the machining head 13. . The rotation cycle of the small pulley 17a can be made smaller than the rotation cycle of the large pulley 17b. Further, the small pulley 17a and the large pulley 17b can be configured such that the small pulley 17a rotates at a non-integer multiple of the rotation period of the large pulley 17b.

  A belt 19 that transmits the rotational force of the small pulley 17a to the large pulley 17b is stretched between the small pulley 17a and the large pulley 17b.

  The small pulley 17a is provided with dogs 20a and 20b, and the large pulley 17b is provided with a dog 20c.

  The origin sensor 16c is arranged so that the dog 20c is detected each time the large pulley 17b rotates 360 ° from the origin position. Further, the OT + sensor 16a is arranged so that the dog 20a is detected so that the dog 20b is not detected when the large pulley 17b is rotated by + 360 ° from the origin position. Further, the OT-sensor 16b is arranged so that the dog 20b is detected so that the dog 20a is not detected when the large pulley 17b is rotated by -360 ° from the origin position.

  Then, when the servo motor 14 is driven by the NC control unit 12 in FIG. 2, the rotation of the servo motor 14 is transmitted to the large pulley 17 b while being decelerated by the speed reducer 18. When the large pulley 17b rotates, the rotational force is transmitted to the small pulley 17a via the belt 19, and the machining head 13 is rotated with the rotation of the small pulley 17a.

  On the other hand, the laser light generated by the laser oscillator 15 is guided to the processing head 13 via the processing machine main body 11 and emitted to the processing object K while the position of the processing head 13 is controlled.

  When the large pulley 17b is rotated by the driving force of the servo motor 14, the dog 20c is detected by the origin sensor 16c every time the large pulley 17b rotates by 360 ° from the origin position, and the detected signal is detected by the rotational position discriminating unit 12a. Sent to.

  Further, when the large pulley 17b rotates clockwise with the rotation of the large pulley 17b, and when the large pulley 17b rotates by + 360 ° from the origin position, the dog 20a is detected by the OT + sensor 16a, and the detection signal is the rotation position. It is sent to the determination unit 12a.

  Further, when the large pulley 17b rotates, the small pulley 17a rotates counterclockwise, and when the large pulley 17b rotates by -360 ° from the origin position, the dog 20b is detected by the OT-sensor 16b, and the detection signal is It is sent to the rotational position determination unit 12a.

  In the rotational position discriminating unit 12a, when the dog 20c is detected by the origin sensor 16c and the dogs 20a and 20b are not detected by the OT + sensor 16a and the OT− sensor 16b, the machining head 13 is at the origin position. The determination result is sent to the motor drive control unit 12b.

  Further, in the rotational position discriminating unit 12a, when the dog 20c is detected by the origin sensor 16c and the dog 20b is not detected by the OT-sensor 16b, the processing is performed when the dog 20a is detected by the OT + sensor 16a. It is determined that the head 13 has rotated by + 360 °, and the determination result is sent to the motor drive control unit 12b.

  Further, in the rotational position determination unit 12a, when the dog 20c is detected by the origin sensor 16c, and the dog 20b is detected by the OT-sensor 16b without the dog 20a being detected by the OT + sensor 16a, the machining is performed It is determined that the head 13 has rotated by −360 °, and the determination result is sent to the motor drive control unit 12b.

  When the stroke of the rotation axis of the machining head 13 is set to 720 °, the rotational position discriminating unit 12a determines that the machining head 13 has rotated by ± 360 ° from the origin position. 12b stops the rotation of the servo motor 14 and prevents the machining head 13 from overtraveling.

  FIG. 4 is a diagram illustrating detection positions of the dogs 20a, 20b, and 20c detected by the OT + sensor 16a, the OT− sensor 16b, and the origin sensor 16c of FIG. 3-2, respectively. In FIG. 4, when the small pulley 17a and the large pulley 17b are rotated, the position of the dog 20a is represented by A, the position of the dog 20b is represented by B, and the position of the dog 20c is represented by C.

  In FIG. 4, the origin sensor is configured so that the dog 20c is detected when the large pulley 17b is at the origin position, at a position rotated by + 360 ° from the origin position, and at a position rotated by −360 ° from the origin position. 16c is arranged.

  The OT + sensor 16a is arranged so that the dog 20a is detected without detecting the dog 20b when the large pulley 17b is rotated by + 360 ° from the origin position. Further, the OT-sensor 16b is arranged so that the dog 20b is detected without detecting the dog 20a when the large pulley 17b is rotated by -360 ° from the origin position.

  Here, since the small pulley 17a rotates at a non-integer multiple of the rotation cycle of the large pulley 17b, the dog 20a is detected by the OT + sensor 16a when the large pulley 17b rotates by + 360 ° from the origin position. By arranging in this manner, the dog 20a is not detected by the OT + sensor 16a when the large pulley 17b is at the origin position and when the large pulley 17b is at a position rotated by −360 ° from the origin position. .

  Further, by arranging the dog 20b to be detected by the OT-sensor 16b when the large pulley 17b rotates by -360 ° from the origin position, the large pulley 17b The dog 20b is not detected by the OT-sensor 16b when the position is rotated by + 360 ° from the origin position.

  For this reason, while the dog 20c is detected by the origin sensor 16c, it can be determined that the machining head 13 is at the origin position when the dogs 20a and 20b are not detected by the OT + sensor 16a and the OT− sensor 16b, respectively.

  Further, while the dog 20c is detected by the origin sensor 16c and the dog 20b is not detected by the OT-sensor 16b, the machining head 13 rotates by + 360 ° when the dog 20a is detected by the OT + sensor 16a. Can be determined.

  Further, the dog 20c is detected by the origin sensor 16c, and the dog 20b is not detected by the OT + sensor 16a. When the dog 20b is detected by the OT− sensor 16b, the machining head 13 is only −360 °. It can be determined that it has rotated.

  Thereby, the rotational position of the rotating shaft having a rotational stroke of 720 ° is detected by using only signals from the OT + sensor 16a, the OT− sensor 16b, and the origin sensor 16c for detecting the presence or absence of the dogs 20a to 20c. It becomes possible to do. For this reason, it is not necessary to convert rotational motion into linear motion or to separately prepare components such as an encoder, a counter, and a comparator in order to detect the rotational position of the rotational shaft having a rotational stroke of 720 °. In addition, it is possible to suppress the increase in cost and reduce the time and effort required for assembly adjustment.

  In the first embodiment described above, the method of using the small pulley 17a, the large pulley 17b, and the belt 19 in order to transmit the driving force from the servo motor 14 to the machining head 13 has been described. However, a gear or the like is used. Thus, the driving force by the servo motor 14 may be transmitted to the machining head 13 side.

  In the first embodiment described above, the method of attaching the dog 20c to the large pulley 17b has been described. However, the attachment position of the dog 20c is not limited to the large pulley 17b, but may be any part that rotates as the machining head 13 rotates. It may be anywhere, for example, it may be directly attached to the machining head 13. In the first embodiment described above, the method of attaching the dogs 20a and 20b to the small pulley 17a has been described. However, the portion is smaller than the rotation cycle of the large pulley 17b and rotates at a non-integer multiple of the rotation cycle of the large pulley 17b. If so, anywhere.

  Further, in the first embodiment described above, the method of providing the two dogs 20a and 20b on the small pulley 17a in order to enable fine adjustment of the detection position has been described. However, the two dogs 20a are not necessarily provided. It is not necessary to provide the dog 20b on the small pulley 17a, and any one of the two dogs 20a and 20b may be omitted. For example, if the dog 20b of the two dogs 20a and 20b is removed, the OT + sensor 16a is arranged so that the dog 20a is detected by the OT + sensor 16a when the large pulley 17b rotates by + 360 °. By arranging the OT-sensor 16b so that the dog 20a is detected by the OT-sensor 16b when the large pulley 17b is rotated by -360 °, the origin position and the position rotated by + 360 ° are- The position rotated by 360 ° can be discriminated.

  In the first embodiment described above, the method for discriminating the origin position, the position rotated by + 360 °, and the position rotated by −360 ° has been described. However, the origin position and +360 N ° (N is positive) You may make it apply to the method of discriminate | determining the position rotated only by (integer) and the position rotated by -360N degree.

  In addition, when N is 2 or more, in order to distinguish the origin position and the position rotated by ± 360 °, for example, after rotating once counterclockwise and OT-detection is performed, this time 360 ° clockwise. It may be rotated as described above to perform origin detection.

Embodiment 2. FIG.
5A is a cross-sectional view illustrating a schematic configuration of a machining head to which the second embodiment of the rotational position detection device according to the present invention is applied, and FIG. 5B is a machining viewed from the E2 direction in FIG. It is an arrow view which shows schematic structure of a head. 5A and 5B, a small pulley 27a is connected to a drive shaft by the servo motor 24 via a speed reducer 28, and a large pulley 27b is connected to a rotating shaft of the machining head. The rotation cycle of the small pulley 27a can be made smaller than the rotation cycle of the large pulley 27b. The small pulley 27a and the large pulley 27b can be configured such that the small pulley 27a rotates at a non-integer multiple of the rotation period of the large pulley 27b.

  A belt 29 for transmitting the rotational force of the small pulley 27a to the large pulley 12b is stretched over the small pulley 27a and the large pulley 27b.

  The small pulley 27a is provided with dogs 30a and 30b, and the large pulley 27b is provided with dogs 30c and 30d. Here, the dog 30d is attached to a position shifted by 180 ° with respect to the dog 30c of the large pulley 27b.

  The origin sensor 26c is arranged so that the dogs 30c and 30d are alternately detected each time the large pulley 27b rotates by 180 ° from the origin position. The OT + sensor 26a is arranged so that the dog 30a is detected so that the dog 30b is not detected when the large pulley 27b rotates by + 180 ° from the origin position. Further, the OT-sensor 26b is arranged so that the dog 30b is detected so that the dog 30a is not detected when the large pulley 27b rotates by -180 ° from the origin position.

  When the large pulley 27b is rotated by the driving force of the servo motor 24, the dogs 30c and 30d are alternately detected by the origin sensor 26c every time the large pulley 27b rotates by 180 ° from the origin position.

  The dog 30a is detected by the OT + sensor 26a when the small pulley 27a rotates clockwise with the rotation of the large pulley 27b and the large pulley 27b rotates by + 180 ° from the origin position.

  The dog 30b is detected by the OT-sensor 26b when the small pulley 27a rotates counterclockwise with the rotation of the large pulley 27b and the large pulley 27b rotates by -180 ° from the origin position.

  When the dog 30c is detected by the origin sensor 26c and the dogs 30a and 30b are not detected by the OT + sensor 26a and the OT− sensor 26b, it is determined that the machining head is at the origin position.

  Further, the dog 30d is detected by the origin sensor 26c, and the dog 30b is not detected by the OT-sensor 26b. When the dog 30a is detected by the OT + sensor 26a, the machining head is rotated by + 180 °. Is determined.

  Furthermore, while the dog 30d is detected by the origin sensor 26c, and the dog 30b is not detected by the OT + sensor 26a, the machining head rotates by −180 ° when the dog 30b is detected by the OT− sensor 26b. It is determined that

  FIG. 6 is a diagram illustrating detection positions of the dogs 30a, 30b, 30c, and 30d detected by the OT + sensor 26a, the OT− sensor 26b, and the origin sensor 26c in FIG. In FIG. 6, when the small pulley 27a and the large pulley 27b are rotated, the position of the dog 30a is represented by A, the position of the dog 30b is represented by B, the position of the dog 30c is represented by C, and the position of the dog 30d is represented. Represented by D.

  In FIG. 6, the dog 30c is detected when the large pulley 27b is at the origin position, and the dog 30d is located at a position rotated by + 180 ° from the origin position and at a position rotated by −180 ° from the origin position. An origin sensor 26c is arranged so as to be detected.

  The OT + sensor 26a is arranged so that the dog 30a is detected without detecting the dog 30b when the large pulley 27b rotates by + 180 ° from the origin position. Further, the OT-sensor 26b is arranged so that the dog 30b is detected without detecting the dog 30a when the large pulley 27b is rotated by -180 ° from the origin position.

  Here, since the small pulley 27a rotates at a non-integer multiple of the rotation cycle of the large pulley 27b, the dog 30a is detected by the OT + sensor 26a when the large pulley 27b rotates by + 180 ° from the origin position. By arranging in this manner, the dog 30a is not detected by the OT + sensor 26a when the large pulley 27b is at the origin position and when the large pulley 27b is at a position rotated by −180 ° from the origin position. .

  Further, by arranging the dog 30b so that the dog 30b is detected by the OT-sensor 26b when the large pulley 27b rotates by -180 ° from the origin position, the large pulley 27b The dog 30b is not detected by the OT-sensor 26b when it is at a position rotated by + 180 ° from the origin position.

  Therefore, the dog 30c is detected by the origin sensor 26c, and when the dogs 30a and 30b are not detected by the OT + sensor 26a and the OT− sensor 26b, it can be determined that the machining head is at the origin position.

  Further, the dog 30d is detected by the origin sensor 26c, and the dog 30b is not detected by the OT-sensor 26b. When the dog 30a is detected by the OT + sensor 26a, the machining head is rotated by + 180 °. Can be determined.

  Furthermore, while the dog 30d is detected by the origin sensor 26c, and the dog 30b is not detected by the OT + sensor 26a, the machining head rotates by −180 ° when the dog 30b is detected by the OT− sensor 26b. Can be determined.

  As a result, the rotational position of the rotating shaft having a rotational stroke of 360 ° is detected by using only signals from the OT + sensor 26a, the OT− sensor 26b, and the origin sensor 26c for detecting the presence or absence of the dogs 30a to 30d. It becomes possible to do. For this reason, it is not necessary to convert rotational motion into linear motion or to separately prepare components such as encoders, counters, and comparators in order to detect the rotational position of a rotary shaft having a 360 ° rotational stroke. In addition, it is possible to suppress the increase in cost and reduce the time and effort required for assembly adjustment.

  In the second embodiment described above, the method using the small pulley 27a, the large pulley 27b, and the belt 29 to transmit the driving force by the servo motor 24 to the machining head side has been described. However, by using a gear or the like. The driving force by the servo motor 24 may be transmitted to the machining head side.

  In the second embodiment described above, the method of attaching the dogs 30c and 30d to the large pulley 27b has been described. However, the attachment positions of the dogs 30c and 30d are rotated in accordance with the rotation of the machining head in addition to the large pulley 27b. Any part may be used. For example, the part may be directly attached to the processing head. In the second embodiment described above, the method of attaching the dogs 30a and 30b to the small pulley 27a has been described. However, the portion is smaller than the rotation cycle of the large pulley 27b and rotates at a non-integer multiple of the rotation cycle of the large pulley 27b. If so, it can be installed anywhere.

  In the second embodiment described above, the method of providing the two dogs 30a and 30b on the small pulley 27a in order to enable fine adjustment of the detection position has been described. However, the two dogs 30a are not necessarily provided. The dog 30b does not need to be provided on the small pulley 27a, and any one of the two dogs 30a and 30b may be omitted. For example, if the dog 30b of the two dogs 30a and 30b is removed, the OT + sensor 26a is arranged so that the dog 30a is detected by the OT + sensor 26a when the large pulley 27b rotates by + 180 °. By arranging the OT-sensor 26b so that the dog 30a is detected by the OT-sensor 26b when the large pulley 27b rotates by -180 °, the origin position, the position rotated by + 180 °, The position rotated by 180 ° can be discriminated.

  In the second embodiment described above, the method of discriminating the origin position, the position rotated by + 180 °, and the position rotated by −180 ° has been described. However, the origin position and +360 (N−1) +180 are described. You may make it apply to the method which discriminate | determines the position rotated only (degree), and the position rotated only -360 (N-1) -180 degree.

  When N is 2 or more, in order to distinguish the origin position and the position rotated by ± 180 °, for example, after rotating once counterclockwise and performing OT-detection, this time 360 ° clockwise. It may be rotated as described above to perform origin detection.

Embodiment 3 FIG.
FIG. 7-1 is a cross-sectional view illustrating a schematic configuration of a machining head to which the third embodiment of the rotational position detection device according to the present invention is applied, and FIG. 7-2 is a machining viewed from the E3 direction of FIG. It is an arrow view which shows schematic structure of a head. 7A and 7B, a small pulley 37 a is connected to a drive shaft by the servo motor 34 via a speed reducer 38, and a large pulley 37 b is connected to a rotation shaft of the machining head 33. . The rotation cycle of the small pulley 37a can be made smaller than the rotation cycle of the large pulley 37b. The small pulley 37a and the large pulley 37b can be configured such that the small pulley 37a rotates at a non-integer multiple of the rotation period of the large pulley 37b.

  A belt 39 for transmitting the rotational force of the small pulley 37a to the large pulley 37b is stretched between the small pulley 37a and the large pulley 37b.

  The small pulley 37a is provided with a dog 40a, and the large pulley 37b is provided with a dog 40c.

  The origin sensor 36c is arranged so that the dog 40c is detected each time the large pulley 37b rotates by 360 ° from the origin position. Further, the OT + sensor 36a detects the dog 40a when the large pulley 37b rotates by −720 ° from the origin position without detecting the dog 40a when the large pulley 37b rotates by + 720 ° from the origin position. Is arranged. The OT-sensor 36b detects the dog 40a when the large pulley 37b rotates by + 720 ° from the origin position without detecting the dog 40a when the large pulley 37b rotates by -720 ° from the origin position. Are arranged as follows.

  When the large pulley 37b rotates by the driving force of the servo motor 34, the dog 40c is detected by the origin sensor 36c every time the large pulley 37b rotates 360 ° from the origin position.

  The dog 40a is detected by the OT-sensor 36b when the small pulley 37a rotates clockwise with the rotation of the large pulley 37b and the large pulley 37b rotates by + 720 ° from the origin position.

  The dog 40a is detected by the OT + sensor 36a when the small pulley 37a rotates counterclockwise with the rotation of the large pulley 37b and the large pulley 37b rotates by -720 ° from the origin position.

  When the dog 40c is detected by the origin sensor 36c and the dog 40a is not detected by the OT + sensor 36a and the OT− sensor 36b, it is determined that the machining head is at the origin position or a position rotated by ± 360 °. .

  In order to distinguish between the origin position and the position rotated by ± 360 °, for example, after rotating once counterclockwise and performing OT-detection, this time rotating clockwise 360 ° or more to detect the origin. You may make it perform.

  Further, the dog 40c is detected by the origin sensor 36c, and the dog 40a is not detected by the OT-sensor 36b. When the dog 40a is detected by the OT + sensor 36a, the machining head rotates by -720 °. It is determined that

  Furthermore, the dog 40c is detected by the origin sensor 36c, and the dog 40a is not detected by the OT + sensor 36a. When the dog 40a is detected by the OT-sensor 36b, the machining head rotates by + 720 °. Is determined.

  FIG. 8 is a diagram illustrating detection positions of the dogs 40a and 40c detected by the OT + sensor 36a, the OT− sensor 36b, and the origin sensor 36c of FIG. 7-2, respectively. In FIG. 8, when the small pulley 37a and the large pulley 37b are rotated, the position of the dog 40a is represented by A, and the position of the dog 40c is represented by C.

  In FIG. 8, when the large pulley 37b is at the origin position, when it is at a position rotated by + 360 ° from the origin position, when it is at a position rotated by −360 ° from the origin position, it is a position rotated by + 720 ° from the origin position. The origin sensor 36c is arranged so that the dog 40c is detected when it is at a position rotated by −720 ° from the origin position.

  Further, the OT-sensor 36b is arranged so that the dog 40a is detected when the large pulley 37b is rotated by + 720 ° from the origin position. Further, the OT + sensor 36a is arranged so that the dog 40a is detected when the large pulley 37b rotates by −720 ° from the origin position.

  Here, since the small pulley 37a is configured to rotate at a non-integer multiple of the rotation cycle of the large pulley 37b, the dog 40a is detected by the OT-sensor 36b when the large pulley 37b rotates by + 720 ° from the origin position. By arranging so that the large pulley 37b is at the origin position, when the large pulley 37b is at a position rotated by + 360 ° from the origin position, the large pulley 37b is rotated by −360 ° from the origin position. The dog 40a is not detected by the OT-sensor 36b when it is in the position and when the large pulley 37b is at a position rotated by −720 ° from the origin position.

  Further, by arranging the dog 40a to be detected by the OT + sensor 36a when the large pulley 37b is rotated by −720 ° from the origin position, the large pulley 37b is at the origin position and the large pulley 37b is at the origin position. OT + when the position is rotated by −360 ° from the position, when the large pulley 37b is rotated by + 360 ° from the origin position, and when the large pulley 37b is rotated by + 720 ° from the origin position. The dog 40a is not detected by the sensor 36a.

  Therefore, the dog 40c is detected by the origin sensor 36c, and when the dog 40a is not detected by the OT + sensor 36a and the OT− sensor 36b, it is determined that the machining head is at the origin position or a position rotated by ± 360 °. be able to.

  In order to distinguish between the origin position and the position rotated by ± 360 °, for example, after rotating once counterclockwise and performing OT-detection, this time rotating clockwise 360 ° or more to detect the origin. You may make it perform.

  Further, the dog 40c is detected by the origin sensor 36c, and the dog 40a is not detected by the OT + sensor 36a. When the dog 40a is detected by the OT-sensor 36b, the machining head rotates by + 720 °. Can be determined.

  Further, the dog 40c is detected by the origin sensor 36c, and the dog 40a is not detected by the OT-sensor 36b. When the dog 40a is detected by the OT + sensor 36a, the machining head rotates by −720 °. Can be determined.

  Thus, the rotational position of the rotating shaft having a rotational stroke of 1440 ° is detected by using only signals from the OT + sensor 36a, the OT− sensor 36b and the origin sensor 36c for detecting the presence or absence of the dogs 40a and 40c, respectively. It becomes possible to do. For this reason, it is not necessary to convert rotational motion into linear motion or to separately prepare components such as an encoder, a counter, and a comparator in order to detect the rotational position of a rotational shaft having a rotational stroke of 1440 °. In addition, it is possible to suppress the increase in cost and reduce the time and effort required for assembly adjustment.

  In the above-described third embodiment, the method of using the small pulley 37a, the large pulley 37b, and the belt 39 to transmit the driving force from the servo motor 34 to the machining head side has been described. However, by using a gear or the like. The driving force by the servo motor 34 may be transmitted to the machining head side.

  In the above-described third embodiment, the method of attaching the dog 40c to the large pulley 37b has been described. However, the attachment position of the dog 40c is not limited to the large pulley 37b, as long as it is a part that rotates with the rotation of the machining head. For example, you may make it attach directly to a process head. In the first embodiment described above, the method of attaching the dog 40a to the small pulley 37a has been described. However, if it is a part that is smaller than the rotation period of the large pulley 37b and rotates at a non-integer multiple of the rotation period of the large pulley 37b. It can be installed anywhere.

  In the third embodiment described above, the method of providing one dog 40a on the small pulley 37a has been described. However, in order to allow fine adjustment of the detection position, two dogs are provided on the small pulley 37a. You may make it provide.

  In the third embodiment described above, the method for discriminating between the position rotated by + 720 ° and the position rotated by −720 ° has been described. However, the position rotated by +360 N ° and the position rotated by −360 N °. You may make it apply to the method of discriminating.

  Moreover, although Embodiment 1-3 mentioned above demonstrated taking the example of the structure which applied the rotational position detection apparatus of this invention to the laser processing machine, the rotational position detection apparatus of this invention is limited to a laser processing machine. For example, it may be applied to rotational position detection of a welding robot or the like, or may be applied to rotational position detection of a manipulator or the like.

  In the first to third embodiments described above, the method of transmitting the driving force of the servo motor to the machining head by the belt drive method has been described. However, when applied to the rotational position detection of the direct drive method, the direct drive method is used. A dummy rotating body having a rotation period smaller than that of the rotating body rotated in a separate manner is provided, and the dummy rotating body is rotated at a non-integer multiple of the rotation period of the rotating body rotated by the direct drive method. Good.

  As described above, the rotational position detection device according to the present invention is rotated by only −360 ° and the origin position, the position rotated by + 360 °, and the −360 ° by using only the signal from the sensor for detecting the presence or absence of the dog. It is suitable for a method for detecting the rotational position of a rotary shaft having a rotational stroke of 360 ° or more without converting the rotational motion into a linear motion.

DESCRIPTION OF SYMBOLS 10 Table 11 Processing machine main body 12 NC control part 12a Rotation position discrimination | determination part 12b Motor drive control part 13, 33 Processing head 14, 24, 34 Servo motor 15 Laser oscillator 16a, 26a OT + sensor 16b, 26b OT-sensor 16c, 26c Origin Sensor K Workpiece 17a, 27a, 37a Small pulley 17b, 27b, 37b Large pulley 18, 28, 38 Reducer 19, 29, 39 Belt 20a-20c, 30a-30d, 40a, 40c Dog

Claims (8)

A first rotating body that rotates in synchronization with the rotation axis;
A second rotating body that rotates at a non-integer multiple of the rotation period of the first rotating body along with the rotation of the first rotating body, and has a smaller rotating period than the first rotating body;
A first dog provided on the first rotating body;
A second dog provided on the second rotating body;
An origin sensor that detects the first dog each time the first rotating body rotates 360 ° from the origin position;
An OT + sensor arranged so that the second dog is detected when the first rotating body is rotated by +360 N ° (N is a positive integer) from the origin position;
An OT-sensor arranged so that the second dog is detected when the first rotating body rotates by −360 N ° from the origin position;
When the first dog is detected by the origin sensor and the second dog is not detected by the OT + sensor and the OT− sensor, it is determined that the first rotating body is at the origin position; The first dog is detected by the origin sensor, and the second dog is not detected by the OT-sensor, and the second dog is detected by the OT + sensor. It is determined that the first rotating body has rotated by +360 N °, the first dog is detected by the origin sensor, and the second dog is not detected by the OT + sensor. A rotational position detecting device comprising: a rotational position determining unit that determines that the first rotating body has rotated by -360 N ° when the second dog is detected by a sensor. A first rotating body that rotates in synchronization with the rotation axis;
A second rotating body that rotates at a non-integer multiple of the rotation period of the first rotating body along with the rotation of the first rotating body, and has a smaller rotating period than the first rotating body;
A first dog provided on the first rotating body;
A second dog provided on the second rotating body;
A third dog provided on the second rotating body;
An origin sensor that detects the first dog each time the first rotating body rotates 360 ° from the origin position;
An OT + sensor arranged so that the second dog is detected so that the third dog is not detected when the first rotating body rotates by +360 N ° (N is a positive integer);
An OT-sensor arranged to detect the third dog so that the second dog is not detected when the first rotating body rotates by -360 N °;
When the first dog is detected by the origin sensor, and the second dog and the third dog are not detected by the OT + sensor and the OT− sensor, the first rotating body is the origin. The first dog is detected by the origin sensor, and the second dog is detected by the OT + sensor without detecting the third dog by the OT− sensor. When the dog is detected, it is determined that the first rotating body has rotated by +360 N °, the first dog is detected by the origin sensor, and the second dog is detected by the OT + sensor. And a rotation position determining unit that determines that the first rotating body has rotated by −360 N ° when the third dog is detected by the OT-sensor. Place Position detection device. A first rotating body that rotates in synchronization with the rotation axis;
A second rotating body that rotates at a non-integer multiple of the rotation period of the first rotating body along with the rotation of the first rotating body, and has a smaller rotating period than the first rotating body;
A first dog provided on the first rotating body;
A second dog provided on the first rotating body at a position shifted by 180 ° with respect to the first dog;
A third dog provided on the second rotating body;
An origin sensor that alternately detects the first dog and the second dog each time the first rotating body rotates by 180 ° from the origin position;
An OT + sensor arranged so that the third dog is detected when the first rotating body rotates by +360 (N−1) + 180 ° (N is a positive integer) from the origin position;
An OT-sensor disposed so that the third dog is detected when the first rotating body rotates by −360 (N−1) −180 ° from the origin position;
When the first dog is detected by the origin sensor and the third dog is not detected by the OT + sensor and the OT− sensor, it is determined that the first rotating body is at the origin position; The second dog is detected by the origin sensor, and the third dog is not detected by the OT-sensor, and the third dog is detected by the OT + sensor. It is determined that the first rotating body has rotated by +360 (N−1) + 180 °, the second dog is detected by the origin sensor, and the third dog is detected by the OT + sensor. And a rotational position determining unit that determines that the first rotating body has rotated by −360 (N−1) −180 ° when the third dog is detected by the OT-sensor. Times characterized by Rotation position detector. A first rotating body that rotates in synchronization with the rotation axis;
A second rotating body that rotates at a non-integer multiple of the rotation period of the first rotating body along with the rotation of the first rotating body, and has a smaller rotating period than the first rotating body;
A first dog provided on the first rotating body;
A second dog provided on the first rotating body at a position shifted by 180 ° with respect to the first dog;
A third dog provided on the second rotating body;
A fourth dog provided on the second rotating body;
An origin sensor that alternately detects the first dog and the second dog each time the first rotating body rotates by 180 ° from the origin position;
The third dog is detected such that the fourth dog is not detected when the first rotating body is rotated by +360 (N−1) + 180 ° (N is a positive integer) from the origin position. An OT + sensor arranged as follows:
The fourth dog is arranged so that the third dog is not detected when the first rotating body is rotated by −360 (N−1) −180 ° from the origin position. OT-sensor,
The first dog is detected when the first dog is detected by the origin sensor, and when the third dog and the fourth dog are not detected by the OT + sensor and the OT- sensor, respectively, The second dog is detected by the origin sensor, and the third dog is detected by the OT + sensor without detecting the fourth dog by the OT− sensor. When the dog is detected, it is determined that the first rotating body has rotated by +360 (N−1) + 180 °, the second dog is detected by the origin sensor, and the OT + sensor detects the second dog. Without the third dog being detected, it is determined that the first rotating body has rotated by −360 (N−1) −180 ° when the fourth dog is detected by the OT-sensor. Rotation position discriminator And a rotational position detecting device. A laser oscillator for generating laser light;
A machining head for emitting laser light generated by the laser oscillator to a workpiece;
A servo motor for generating a driving force for rotating the machining head;
A large pulley that rotates in synchronization with the rotation axis of the machining head;
Provided on the drive shaft side by the servo motor, rotates at a non-integer multiple of the rotation period of the large pulley, and a small pulley having a rotation period smaller than that of the large pulley;
A first dog provided on the large pulley;
A second dog provided on the small pulley;
An origin sensor that detects the first dog each time the machining head rotates 360 ° from the origin position;
An OT + sensor arranged to detect the second dog when the large pulley is rotated by +360 N ° (N is a positive integer) from the origin position;
An OT-sensor arranged so that the second dog is detected when the large pulley is rotated by -360 N ° from the origin position;
When the first dog is detected by the origin sensor and the second dog is not detected by the OT + sensor and the OT− sensor, it is determined that the machining head is at the origin position, and the origin sensor When the first dog is detected by the OT + sensor and the second dog is detected by the OT-sensor without detecting the second dog, the machining head is The first dog is detected by the origin sensor, the second dog is not detected by the OT + sensor, and the OT− sensor detects the first dog. A rotational position discriminating unit that discriminates that the machining head has rotated by −360 N ° when a dog of 2 is detected;
A laser processing machine comprising: a motor drive control unit that performs drive control of the servo motor based on a determination result by the rotational position determination unit. A laser oscillator for generating laser light;
A machining head for emitting laser light generated by the laser oscillator to a workpiece;
A servo motor for generating a driving force for rotating the machining head;
A large pulley that rotates in synchronization with the rotation axis of the machining head;
Provided on the drive shaft side by the servo motor, rotates at a non-integer multiple of the rotation period of the large pulley, and a small pulley having a rotation period smaller than that of the large pulley;
A first dog provided on the large pulley;
A second dog provided on the small pulley;
A third dog provided on the small pulley;
An origin sensor that detects the first dog each time the machining head rotates 360 ° from the origin position;
An OT + sensor arranged so that the second dog is detected so that the third dog is not detected when the large pulley is rotated by +360 N ° (N is a positive integer) from the origin position;
An OT-sensor arranged so that the third dog is detected so that the second dog is not detected when the large pulley is rotated by -360 N ° from the origin position;
The first head is detected by the origin sensor, and the machining head is at the origin position when the second dog and the third dog are not detected by the OT + sensor and the OT- sensor, respectively. And the first dog is detected by the origin sensor, and the second dog is detected by the OT + sensor without the third dog being detected by the OT-sensor. It is determined that the machining head is rotated by +360 N ° when the first dog is detected, the first dog is detected by the origin sensor, and the second dog is not detected by the OT + sensor. A rotational position determination unit that determines that the machining head has rotated by −360 N ° when the third dog is detected by an OT-sensor;
A laser processing machine comprising: a motor drive control unit that performs drive control of the servo motor based on a determination result by the rotational position determination unit. A laser oscillator for generating laser light;
A machining head for emitting laser light generated by the laser oscillator to a workpiece;
A servo motor for generating a driving force for rotating the machining head;
A large pulley that rotates in synchronization with the rotation axis of the machining head;
Provided on the drive shaft side by the servo motor, rotates at a non-integer multiple of the rotation period of the large pulley, and a small pulley having a rotation period smaller than that of the large pulley;
A first dog provided on the large pulley;
A second dog provided on the large pulley at a position shifted by 180 ° with respect to the first dog;
A third dog provided on the small pulley;
An origin sensor that alternately detects the first dog and the second dog each time the machining head rotates by 180 ° from the origin position;
An OT + sensor arranged so that the third dog is detected when the large pulley is rotated by +360 (N-1) + 180 ° (N is a positive integer) from the origin position;
An OT-sensor arranged so that the third dog is detected when the large pulley is rotated by −360 (N−1) −180 ° from the origin position;
When the first dog is detected by the origin sensor and the third dog is not detected by the OT + sensor and the OT− sensor, it is determined that the machining head is at the origin position, and the origin sensor When the second dog is detected at the same time, the third dog is not detected by the OT− sensor, and the third head is detected by the OT + sensor. It is determined that the rotation has been performed by +360 (N−1) + 180 °, the second dog is detected by the origin sensor, and the third dog is not detected by the OT + sensor. A rotational position determination unit that determines that the machining head has rotated by −360 (N−1) −180 ° when the third dog is detected by the sensor;
A laser processing machine comprising: a motor drive control unit that performs drive control of the servo motor based on a determination result by the rotational position determination unit. A laser oscillator for generating laser light;
A machining head for emitting laser light generated by the laser oscillator to a workpiece;
A servo motor for generating a driving force for rotating the machining head;
A large pulley that rotates in synchronization with the rotation axis of the machining head;
Provided on the drive shaft side by the servo motor, rotates at a non-integer multiple of the rotation period of the large pulley, and a small pulley having a rotation period smaller than that of the large pulley;
A first dog provided on the large pulley;
A second dog provided on the large pulley at a position shifted by 180 ° with respect to the first dog;
A third dog provided on the small pulley;
A fourth dog provided on the small pulley;
An origin sensor that alternately detects the first dog and the second dog each time the machining head rotates by 180 ° from the origin position;
Arrangement is made so that the fourth dog is not detected when the large pulley is rotated by +360 (N−1) + 180 ° (N is a positive integer) from the origin position. An OT + sensor,
An OT-sensor arranged so that the fourth dog is detected so that the third dog is not detected when the large pulley is rotated by −360 (N−1) −180 ° from the origin position. When,
The first dog is detected by the origin sensor, and the machining head is at the origin position when the third dog and the fourth dog are not detected by the OT + sensor and the OT- sensor, respectively. And the second dog is detected by the origin sensor, and the third dog is detected by the OT + sensor without the fourth dog being detected by the OT− sensor. It is determined that the machining head has rotated by +360 (N−1) + 180 ° when the second dog is detected, the second dog is detected by the origin sensor, and the third dog is detected by the OT + sensor. Without being done, when the fourth dog is detected by the OT-sensor, a rotational position determination unit that determines that the machining head has rotated by −360 (N−1) −180 °,
A laser processing machine comprising: a motor drive control unit that performs drive control of the servo motor based on a determination result by the rotational position determination unit.

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