JP2014172114A - Centering device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a centering device capable of easily and automatically performing centering operation with no temporary placement jig required when placing a work on a rotary table.SOLUTION: The centering device includes a rotary table 16 which is rotated around an axis by a rotational drive mechanism 20 with a work placed and fixed on an upper surface, a pusher device 25 which includes a rod-like push rod reciprocating in a normal direction of the rotary table 16 and is arranged farther outside than the rotary table 16 in the normal direction, and a stopper device 40 which includes an engaging member reciprocating in the normal direction, with an interval of about 90° from the pusher device 25 along the circumferential direction of the rotary table 16, to be arranged farther outside from the rotary table 16 in the normal direction. A control unit 50 executes a reference value determination process, a fluctuation amount calculation process, and a fluctuation maximum phase determination process, and executes a centering process on the basis of a reference value, a fluctuation amount, and a fluctuation maximum phase.

Description

  The present invention relates to a centering device for centering a workpiece placed on a rotary table.

  In order to perform machining on a workpiece with high accuracy, it is necessary to perform a so-called centering operation for aligning the position from the center of the workpiece when performing machining, and conventionally, as a centering device for performing this centering operation, For example, an automatic centering device disclosed in Japanese Patent Laid-Open No. 60-238258 has been proposed.

  The automatic centering device is provided with a rotary table on which a work is placed and provided so as to be rotatable around a rotation center axis, a rotational angle position detector for detecting a rotational angular position of the rotary table, and a correction head at a tip. A correction machine that presses the work toward the rotation center axis, a contact-type radial displacement detector that is provided at the tip of the correction head and detects a radial displacement of the work outer peripheral surface with respect to the rotation center axis; Based on the detection result of the rotation angle position detector and the detection result of the radial direction displacement detector, an arithmetic control circuit for calculating the rotation angle position of the work whose correction is to be corrected and its correction amount are provided.

  According to this automatic centering device, first, the tip of the correction head, that is, the radial displacement detector is brought into contact with the outer peripheral surface of the work placed on the rotary table, and then the rotary table is rotated. Along with this, the arithmetic control circuit reads the rotation angle position of the rotary table detected by the rotation angle position detector at a predetermined cycle, and calculates the displacement amount for each workpiece reading time detected by the radial displacement detector. Read.

  Then, the arithmetic control circuit calculates a misalignment amount from the read displacement amount, and when the calculated misalignment amount is equal to or larger than a set allowable misalignment amount, the rotation angle at which the misalignment amount is maximized. A drive command signal is appropriately issued to rotate the rotary table so that the position matches the position of the tip of the correction head.

  Thereafter, the arithmetic control circuit appropriately issues a drive command signal to advance the correction head by the amount of misalignment. Thereby, the misalignment of the workpiece is corrected, and the centering operation is completed.

JP 60-238258 A

  By the way, in the conventional automatic centering device, as described above, in order to detect the displacement of the workpiece, it is necessary to bring the radial displacement detector into contact with the workpiece. It is necessary to mount the work in advance within the allowable range. Therefore, in the conventional automatic centering device, when placing the work on the rotary table, the work is placed at an appropriate position by using a temporary placement jig or the like as appropriate so that the work is positioned within the allowable measurement range. Must be placed.

  Also, even if the displacement detector is a non-contact type and it is not necessary to make the displacement detector contact the workpiece, to reduce the amount of misalignment as much as possible and reduce the time required for centering work In this case, it is necessary to place the work in a proper position to some extent. At this time, a temporary placing jig or the like must be used.

  However, when a temporary placement jig or the like is used, there is a problem that the temporary placement jig needs to be attached and removed every time the workpiece is replaced, and the centering work becomes complicated.

  The present invention has been made in view of the above circumstances, and does not require a temporary placing jig or the like when placing a work on a rotary table, and can perform a centering operation easily and automatically. The purpose is to provide

The present invention for solving the above problems relates to a centering device that performs centering of a work mounted on a rotary table,
This centering device
A disk-shaped rotary table on which a workpiece is attached;
A rotation drive mechanism for rotating the rotary table about an axis;
A phase detection mechanism for detecting the phase of the rotary table;
A pusher mechanism provided with an axial pressing member that advances and retreats along the normal direction of the rotary table, and is disposed outward of the normal direction with respect to the rotary table;
A locking member that contacts the outer peripheral surface of the work is provided at a position farther from the rotation center of the rotary table than the work radius, and is disposed outwardly in the normal direction with respect to the rotary table. A stopper mechanism;
A displacement detection mechanism that is arranged in parallel at the tip of the pressing member and detects the displacement in the normal direction of the workpiece on the rotary table;
A control device for controlling the operation of the rotation drive mechanism and the pusher mechanism,
The controller is
A reference value is determined based on the displacement detected by the displacement detection mechanism, the rotation table is rotated by controlling the operation of the rotation drive mechanism, and the rotation table detected by the detected displacement and the phase detection mechanism. Determining the phase of the rotary table that maximizes the workpiece deflection based on the phase of the workpiece, and calculating the workpiece deflection based on the displacement detected by the displacement detection mechanism,
The operation of the rotary drive mechanism is controlled to rotate the rotary table, the phase of the rotary table at which the calculated workpiece deflection is maximized is made to coincide with the phase facing the tip of the pressing member, and the pusher mechanism After controlling the operation to move the pushing member to a position where the displacement detected by the displacement detecting mechanism becomes the reference value, the pushing member is advanced toward the workpiece, and the workpiece is moved by the amount of deflection. It is configured to perform the process of moving only.

  According to this centering device, first, the advancing / retreating position of the locking member of the stopper mechanism is a position where the tip of the locking member abuts at a position farther from the rotation center of the rotary table than the radius of the workpiece to be placed. And the advance / retreat position of the pressing member is automatically adjusted so that the distance from the rotation center to the tip of the pressing member is substantially equal to the radius of the workpiece. Then, the work is placed on the surface of the rotary table in a state where the outer peripheral surface of the work is in contact with the respective tips of the pressing member and the locking member.

  Next, a reference value is determined based on the displacement detected by the displacement detection mechanism. As a method for determining the reference value, the amount of displacement detected by the displacement detection mechanism when the pressing member is in contact with the outer peripheral surface of the workpiece may be determined as the reference value.

  Next, under the control of the control device, the rotary table is rotated around the axis by the rotary drive mechanism. At this time, the advancing / retreating position of the pressing member of the pusher mechanism is adjusted so that the tip of the pressing member is located outward of the outer peripheral surface of the workpiece in the normal direction.

  Next, in a state where the rotary table is rotated, the phase of the rotary table that maximizes the deflection of the workpiece (from the phase of the rotary table detected by the phase detection mechanism and the displacement of the workpiece detected by the displacement detection mechanism) (Hereinafter referred to as “maximum deflection phase”) is determined by the control device, and based on the workpiece displacement detected by the displacement detection mechanism, the workpiece deflection amount (center misalignment amount) is calculated by the control device.

  As a method for calculating the workpiece deflection, for example, the maximum value of the detected displacements and the value of the displacement at a phase shifted by 180 ° from the phase where the displacement becomes the maximum value are extracted, and these two values are extracted. A calculation method of dividing the sum of 2 by 2 can be exemplified. In addition, as a method of determining the maximum deflection phase, the phase at the time when the displacement value changes from increasing to decreasing while the workpiece is rotated and the displacement value increasing when the workpiece is rotated in the reverse direction are used. It is possible to exemplify a method of detecting a phase at a time point when a certain amount is changed to decrease, and determining the phase between the two as the maximum deflection phase of the workpiece.

  Thereafter, under the control of the control device, the rotary table is rotated so that the maximum deflection phase coincides with the phase facing the front end of the pressing member. Thereafter, the pusher mechanism is controlled by the control device, the displacement detected by the displacement detection mechanism is moved to a position where the reference value is reached, and then the pushing member is advanced toward the workpiece. The tip is pressed against the workpiece, and the workpiece is moved by the calculated amount of deflection. Thereby, the centering of the workpiece is completed.

  As described above, in this centering device, the tip of the locking member in the stopper mechanism is located farther from the rotation center of the rotary table than the radius of the workpiece, and the tip of the locking member Since the work is placed so that the outer peripheral surface comes into contact with the outer peripheral surface, a gap is secured between the tip of the locking member and the outer peripheral surface of the work when the centering is completed. Therefore, unlike the conventional temporary placement jig, it is not necessary to perform an operation for attaching the stopper mechanism itself when placing a workpiece, and it is not necessary to perform an operation to remove this after completion of centering. The workpiece can be easily replaced, and the complexity in the centering operation can be eliminated.

The control device in the centering device is
A reference value determination unit that determines a reference value based on the displacement detected by the displacement detection mechanism;
The workpiece displacement detected by the displacement detection mechanism and the phase of the rotary table detected by the phase detection mechanism are acquired, and the deflection of the workpiece is maximized based on the acquired displacement of the workpiece and the phase of the rotary table. A maximum runout phase determination unit that determines the phase of the rotary table;
A displacement amount calculating unit that obtains a displacement of the workpiece detected by the displacement detection mechanism, and calculates a maximum deflection amount of the workpiece based on the obtained displacement of the workpiece;
A reference value determination process for determining a reference value based on the displacement detected by the displacement detection mechanism;
Based on the displacement of the workpiece and the phase of the rotary table, the maximum shake phase determination process for determining the phase of the rotary table that maximizes the shake amount;
In a state in which the rotation table is rotated by controlling the operation of the rotation drive mechanism, the displacement detection mechanism detects the displacement of the workpiece, and calculates the maximum deflection amount of the workpiece based on the detected workpiece displacement. When,
The operation of the rotation drive mechanism is controlled to rotate the rotary table, the determined maximum deflection phase is matched with the phase facing the tip of the pressing member, and the operation of the pusher mechanism is controlled, A core that moves the pressing member to the position where the displacement detected by the displacement detection mechanism becomes the reference value, then advances the pressing member toward the workpiece, and moves the workpiece by the maximum deflection amount. It is preferable to execute the unloading process.

  In this case, after the workpiece is placed on the surface of the rotary table with the outer peripheral surface in contact with the respective ends of the pressing member and the locking member, the reference value determining unit detects the workpiece detected by the displacement detection mechanism. The displacement amount is acquired, and the reference value is determined by the reference value determination unit.

  Next, the rotary drive mechanism is controlled to rotate the rotary table. When rotating the rotary table, the pusher mechanism is controlled so that the pressing member is retracted to a position where it does not come into contact with the workpiece when the rotary table rotates.

  Next, in the state in which the rotary table is rotated, the deflection maximum phase determination unit acquires the displacement of the workpiece detected by the displacement detection mechanism and the phase of the rotary table detected by the phase detection mechanism, and the maximum deflection phase determination is performed. The maximum shake phase is determined in the section.

  Further, the shake amount calculation unit obtains the displacement of the workpiece detected by the displacement detection mechanism, and the shake amount calculation unit calculates the shake amount of the workpiece.

  Next, the rotary drive mechanism is controlled by the control device, and then the rotary table is rotated to match the maximum deflection phase with the phase facing the tip of the pressing member. Next, the pusher mechanism is controlled by the control device, and the pressing member is moved to a position where the displacement detected by the displacement detection mechanism becomes the reference value, and then the workpiece is moved by the amount of the shake, The pushing member is advanced toward the workpiece. Then, after the workpiece W is moved by the amount of deflection, the pressing member of the pusher mechanism is retracted. Thereby, the workpiece is centered.

  The control device performs the shake maximum phase determination process, the shake amount calculation process, and the centering process until the work shake amount falls within a predetermined range or the number of repetitions of the three processes reaches a predetermined number. It is preferable that the three processes are repeatedly executed. In this way, the workpiece can be centered more accurately.

  The maximum shake phase determination unit in the control device recognizes the phase at the time when the displacement of the workpiece detected by the displacement detection mechanism turns from increasing to decreasing with the rotary table rotated in one direction. At the same time, the phase at the time when the displacement of the workpiece detected when the rotary table is rotated in the reverse direction is changed from increasing to decreasing is recognized, and the phase between these two recognized phases is determined. It is preferable to perform a process for determining the phase of the rotary table that is maximized.

  Thus, it is preferable to recognize the phase when rotated in the two directions and determine the phase between these two recognized phases as the maximum shake phase for the following reason. That is, the phase recognized in the state of rotating in one direction is the phase at the time when the displacement of the workpiece has changed from increase to decrease, and is not the original maximum shake phase at which the detected displacement becomes the maximum value. By determining the phase between the phase recognized when rotating in the direction and the phase recognized when rotating in the opposite direction as the maximum shake phase, the maximum shake phase closer to the original maximum shake phase is determined. Because it can.

  As described above, according to the centering device of the present invention, the workpiece can be automatically centered without using a temporary placing jig, and the stopper mechanism needs to be attached or removed. Therefore, the workpiece can be easily replaced, and the complexity of the centering operation can be eliminated.

It is a perspective view which shows the vertical grinding machine provided with the centering apparatus which concerns on one Embodiment of this invention. It is a perspective view which shows a centering apparatus. It is sectional drawing which shows a pusher mechanism. It is a top view which shows a stopper mechanism. It is the front view seen from the arrow A direction in FIG. It is the side view seen from the arrow B direction in FIG. It is the block diagram which showed the structure of the control apparatus in a centering apparatus. It is the flowchart which showed a series of processes in the control apparatus of this embodiment. It is the flowchart which showed a series of processes in the reference value determination part of this embodiment. It is the flowchart which showed a series of processes in the shake maximum phase determination part of this embodiment. It is the flowchart which showed a series of processes in the shake amount calculation part of this embodiment. It is explanatory drawing for demonstrating the process of centering work.

  Hereinafter, specific embodiments of the present invention will be described with reference to the drawings. In the following, a vertical grinding machine equipped with a centering device will be described as an example.

  As shown in FIG. 1, a vertical grinding machine 1 having a centering device 15 of this example includes a bed 2, a column 3 erected on the upper surface of the bed 2, an X-axis moving unit 7, and a Z-axis. The feed unit 5 includes a moving unit 8 and a rotating unit 9, and the X-axis moving unit 7 is supported by the column 3. The grinding wheel base 10 is fixed to the rotating unit 9 and rotatably supports the grinding wheel 11. And a centering device 15 disposed on the upper surface of the bed 2 and a control device 50 for NC controlling the operations of the feeding device 5 and the centering device 15.

  The X-axis moving unit 7 includes an X-axis moving table 7a, an X-axis guide rail (not shown), and the like. The X-axis moving table 7a is appropriately moved along the X-axis guide rail by a feed screw mechanism such as a ball screw. It is supposed to move. The Z-axis moving unit 8 is supported by the X-axis moving table 7a and includes a Z-axis moving table 8a, a Z-axis guide rail (not shown), and the like. It moves along the guide rail. The rotating unit 9 is supported by the Z-axis moving table 8a and includes a rotating table 9a and an appropriate drive mechanism for rotating the rotating table 9a. The rotating table 9a rotates in the XZ plane. ing.

  The whetstone base 10 includes a cylindrical whetstone base body 10a, a rotary shaft 10b that is rotatably provided at the tip of the whetstone base body 10a, and the like. The whetstone base body 10a is fixed to the front surface of the rotary base 9a. It is installed. Further, a grinding wheel 11 is appropriately attached to the tip of the rotating shaft 10b by a clamping mechanism, and the grinding wheel 11 is appropriately rotated at a predetermined speed by a rotational drive mechanism.

  Thus, the grinding wheel 11 supported by the grinding wheel base 10 moves as the X-axis moving base 7a of the X-axis moving unit 7 of the feeding device 5 and the Z-axis moving base 8a of the Z-axis moving unit 8 move. It moves in the direction of the axis and the Z axis, and rotates in the XZ plane by rotating the turntable 9a of the rotary unit 9.

  Next, the centering device 15 will be described with reference to FIGS.

  As shown in FIG. 2, the centering device 15 detects the phase of the rotary table 16 that is rotated about the axis by the rotary drive mechanism 20 and on which the workpiece W is placed and fixed, and the rotary table 16. A pusher device 25 that includes a phase detector 23 and an axial push rod 29 that advances and retreats along the normal direction of the rotary table 16, and is disposed outward of the rotary table 16 in the normal direction; A locking member 45 that advances and retreats along the linear direction is provided, is spaced approximately 90 ° from the pusher device 25 in the circumferential direction of the rotary table 16, and is more outward in the normal direction than the rotary table 16. It is comprised from the stopper apparatus 40 arrange | positioned by this.

  The rotary table 16 is a so-called electromagnetic chuck in which the upper surface of the rotary table 16 fixes the workpiece W by an attracting action by electromagnetic force, and the fixing strength of the workpiece W can be adjusted by adjusting the magnetizing force. It has become. The chuck mechanism for fixing the workpiece W is not limited to an electromagnetic chuck, and may be a chuck mechanism that mechanically fixes the workpiece W.

  The rotation drive mechanism 20 includes a drive motor 21 whose operation is controlled by the control device 50, a rotation transmission mechanism (not shown) that transmits the rotation of the drive motor 21, and the like. It is arranged. The phase detector 23 includes a rotary encoder connected to the drive motor 21, detects the phase of the rotary table 16 based on the rotational position of the drive motor 21, and outputs the detected phase to the control device 50. To do.

  Next, the pusher device 25 will be described with reference to FIG. FIG. 3 is a cross-sectional view of the pusher device 25.

  The pusher device 25 includes a drive motor 26 in which a first gear 28 is attached to a rotary shaft 27, a push rod 29 in which a through hole 29a is formed along the axis, and a work W fixed on the rotary table 16. A displacement detector 32 for detecting displacement; a feed screw 33 having a second gear 34 engaged with the first gear 28 on the rear end side; a drive motor 26; two gears 28 and 34; a push rod 29; The housing 35 accommodates the feed screw 33 and is fixed on the support member 17 disposed so as to surround the rotary table 16.

  The housing 35 has an opening formed in the rear end surface thereof, and a housing case 36 in which the drive motor 26 is housed. The housing 35 is fixed to the rear end surface of the housing case 36, and the first and second gears 28 and 34 are provided. The gear case 37 includes a gear case 37 to be stored, and a cylindrical guide case 38 that is fixed to the front end surface of the gear case 37 so as to be positioned below the storage case 36 and that stores the push rod 29. In the front end surface, through holes 37a and 37b are respectively formed in a portion facing the storage case 36 and a portion facing the guide case 38. The space in the storage case 36 and the space in the gear case 37 are defined as follows. The rotation shaft 27 communicates so that it can be inserted, and the space in the gear case 37 and the space in the guide case 38 communicate so that the feed screw 33 can be inserted. The gear case 37 has a lid 37c fixed to the rear end surface in a state where the first and second gears 28 and 34 are accommodated.

  The drive motor 26 is a servo motor, for example, and its operation is controlled by the control device 50. The drive motor 26 is housed in the housing case 36 so that the first gear 28 is disposed in the gear case 37 with the rotating shaft 27 facing rearward. The drive motor 26 is connected to an encoder (not shown) for detecting the rotational position, and this encoder outputs the angular position of the drive motor 26 to the control device 50.

  The push rod 29 has a nut 30 fixed to the rear end portion thereof, and is inserted into the guide case 38 so as to be able to advance and retract in the front-rear direction in a state where a feed screw 33 is screwed onto the nut 30. In addition, a pressing body 31 that is pressed against the workpiece W is fixed to the distal end portion of the push rod 29.

  The displacement detector 32 is a non-contact type displacement detector, and is fixed to a position slightly recessed from the front end surface of the pressing body 31 of the push rod 29, and the pressing body 31 is fixed to the workpiece W. When the contact is made, the displacement of the workpiece W is detected without contacting the workpiece W. Further, the displacement detector 32 outputs the detected displacement of the workpiece W to the control device 50. In this example, the displacement detector 32 is a non-contact type, but may be a contact type displacement detector.

  As described above, the second screw 34 is attached to the rear end side of the feed screw 33, and the front end side is screwed onto the nut 30 in a state where the second gear 34 is disposed in the gear case 37. Are combined.

  Thus, according to the pusher device 25, when the drive motor 26 is rotated and the rotary shaft 27 is rotated under the control of the control device 50, the first and second gears 28, with which the tooth portions mesh with each other, The rotation is transmitted to the feed screw 33 by 34, and the push rod 29 screwed into the feed screw 33 advances and retreats along the normal direction.

  Next, the stopper device 40 will be described with reference to FIGS.

  The stopper device 40 is provided on the base 41 fixed to the support member 17, a shaft-like locking member 45 supported by the base 41, and the base 41, and fixes the locking member 45. And a clamper 49 for the purpose.

  The base 41 is formed with a support portion 42 on the upper surface of which the locking member 45 is supported so as to be able to advance and retreat. The support portion 42 has a through hole 43a through which the locking member 45 is inserted. It consists of the 1st support part 43 and the 2nd support part 44 in which the engaging groove 44a with which the latching member 45 engages was formed.

  The first support portion 43 has a split groove 43b penetrating from the side surface thereof to the inner peripheral surface of the through hole 43a and penetrating from the front surface to the back surface, and is open to the upper surface. The engagement holes 43c are formed in the inner wall surfaces of the two and the threaded grooves are formed in the lower portion of the split groove 43b. Further, the first support portion 43 has a notch 43d formed on the upper surface thereof, and a groove 43e is formed along the through hole 43a so as to penetrate from the bottom surface of the notch 43d to the inner peripheral surface of the through hole 43a. Is formed.

  The locking member 45 has a square column-shaped gauge 47 with a scale displayed on a part of the outer peripheral surface thereof, and is fixed along the axial direction of the locking member 45. The first support portion 43 is supported by the first support portion 43 in a state where the groove 43e of the first support portion 43 is engaged. An instruction plate 43f indicating the scale of the gauge 47 is fixed on the bottom surface of the notch 43d.

  The clamper 49 is formed with a threaded portion on one end side, and the clamp screw 49a inserted into the engagement hole 43c so that the threaded portion is screwed into the thread groove of the engagement hole 43c, and the clamp It consists of a handle 49b attached to the other end of the screw 49a.

  Thus, according to the stopper device 40, the advancement / retraction position of the locking member 45 is manually adjusted while referring to the scale pointed by the instruction plate 43f, and then the clamping screw 49a is rotated via the handle 49b. By doing so, the width of the split groove 43b is narrowed, and the locking member 45 inserted through the through hole 43a is fixed at a predetermined position.

  As shown in FIG. 7, the control device 50 includes a reference value determination unit 51 that determines the value of the displacement detector when the tip of the push rod 29 of the pusher device 25 is at a predetermined position as a reference value, and a workpiece W A shake amount calculation unit 52 that calculates a shake amount of the workpiece, a shake maximum phase determination unit 53 that determines a phase (a shake maximum phase) of the rotary table 16 that maximizes the shake of the workpiece W, a reference value, a shake amount, and a shake maximum. It comprises a main control unit 56 that performs centering processing based on the phase, a rotation drive mechanism control unit 54 that controls the operation of the rotation drive mechanism 20, and a pusher device control unit 55 that controls the operation of the pusher device 25. The main control unit 56 executes a series of processes shown in FIG. 8, the reference value determining unit 51 executes a series of processes shown in FIG. 9, and the maximum shake phase determining unit 53 is shown in FIG. The shake amount calculation unit 52 executes a series of processes shown in FIG. Further, the rotation drive mechanism control unit 54 rotates the drive motor 21 so that the phase of the rotary table detected by the phase detector 23 becomes a predetermined phase, and the pusher device control unit 55 performs the first gear. The drive motor 26 is rotated so that the position of the pusher rod 29 becomes a predetermined position on the basis of the reduction ratio of 28 and the second gear 34 and the angular position of the drive motor 26 detected by the encoder as appropriate. In addition, about the function part which controls operation | movement of the feeder 5 etc., the illustration was abbreviate | omitted.

  Hereinafter, the processing flow executed by the control device 50 will be described with reference to FIGS.

  First, the main control unit 56 checks whether or not the determination of the reference value is completed (step S1), and if it is determined that the determination of the reference value is not completed, the reference value determination unit 51 determines the reference value. If the process is executed and it is determined that the determination of the reference value is completed, the process proceeds to step S4.

  First, the reference value determination unit 51 acquires the displacement amount detected by the displacement detector 32 via the main control unit 56 in a state where the pressing body 31 is in contact with the outer peripheral surface of the workpiece W (step S2). Then, the obtained displacement amount is determined as a reference value (step S3), and the process proceeds to step S1.

  Next, the main control unit 56 checks whether or not the determination of the maximum shake phase has been completed (step S4). If it is determined that the determination has not been completed, the maximum shake phase determination unit 53 determines the maximum shake phase determination process. If it is determined that the process has been completed, the process proceeds to step S16.

  In the shake maximum phase determination unit 53, first, an operation command is transmitted to the pusher device control unit 55 via the main control unit 56, the drive motor 26 is rotated by the pusher device control unit 55, and the rotary table 16 is rotated. The push rod 29 is retracted to a position where the pressing body 31 does not come into contact with the workpiece W (step S5). Next, an operation command is transmitted to the rotation drive mechanism control unit 54 via the main control unit 56, the drive motor 21 is rotated by the rotation drive mechanism control unit 54, and the rotation table 16 is rotated in either the forward or reverse direction. (Step S6), the displacement detected by the displacement detector 32 in this state is acquired via the main controller 56 (Step S7). Then, it is confirmed whether or not the displacement has changed from increasing to decreasing (in other words, whether or not the displacement change amount has exceeded the maximum value) (step S8), and if it is determined that the displacement has not changed from increasing to decreasing. When it is determined that the process after step S7 is executed again and the increase is reduced, the phase detected by the phase detector 23 at that time is appropriately stored in the storage unit as the temporary shake maximum phase (step S9), the process proceeds to step S10.

  Next, an operation command is transmitted to the rotation drive mechanism control unit 54 via the main control unit 56, the drive motor 21 is rotated by the control unit 54, and the rotary table 16 is rotated in the direction opposite to the above ( In step S10), the displacement detected by the displacement detector 32 in this state is acquired via the main controller 56 (step S11). Thereafter, similarly, it is confirmed whether or not the displacement has changed from an increase to a decrease (step S12). When it is determined that the displacement has not changed, the processing after step S11 is executed again. The phase detected at that time is appropriately stored in the storage unit as a temporary maximum shake phase (step S13).

  Then, the two stored temporary maximum shake phases are read (step S14), and an intermediate phase between the two read temporary maximum shake phases is determined as the maximum shake phase (step S15), and the process proceeds to step S4.

  Next, the main control unit 56 checks whether or not the shake amount calculation has been completed (step S16). If it is determined that the shake amount calculation has not been completed, the shake amount calculation unit 52 executes a shake amount calculation process. If it is determined that the shake amount calculation has been completed, the process proceeds to step S21.

  In the shake amount calculation unit 52, first, an operation command is transmitted to the rotation drive mechanism control unit 54 via the main control unit 56, the drive motor 21 is rotated by the rotation drive mechanism control unit 54, and the turntable 16. Is rotated forward or backward (step S17). Next, with the rotary table 16 rotated, the displacement detected by the displacement detector 32 is acquired via the main controller 56 (step S18), and the process proceeds to step S19.

  In step S19, it is confirmed whether or not the maximum value of displacement and the value of displacement at a phase shifted by 180 ° from the phase at which this displacement becomes the maximum value are obtained. Step S18 is executed again. On the other hand, if it is determined that it has been acquired, the sum of the two acquired values is divided by two to calculate the amount of deflection of the workpiece W (step S20), and the process proceeds to step S16.

  Next, the main control unit 56 checks whether or not the calculated shake amount is within a preset allowable range (step S21). If it is determined that the calculated shake amount is within the allowable range, all processing is performed. If it is determined that it is not within the allowable range, the process proceeds to step S22.

  Next, the main control unit 56 reads the reference value, the shake amount, and the shake maximum phase (step S22), transmits an operation command to the rotation drive mechanism control unit 54, and rotates the drive motor 21 by the rotation drive mechanism control unit 54. Thus, the read maximum shake phase is matched with the phase facing the push rod 29 of the pusher device 25 (step S23), and the process proceeds to step S24. In step S24, an operation command is transmitted to the pusher device control unit 55, the drive motor 26 is rotated by the pusher device control unit 55, and the displacement detected by the displacement detector 32 reaches a position where the reference value is obtained. After the pusher rod 29 is moved, the drive motor 26 is further rotated to move the push rod 29 by the calculated amount of deflection. Thereafter, the processing after step S5 is executed again.

  Next, the process of centering the workpiece W in the vertical grinding machine 1 having the above configuration will be described in detail with reference to FIG.

  First, the scale pointed by the instruction plate 43f is referred to so that the tip of the locking member 45 is located at a position away from the rotation center of the rotary table 16 than the radius of the work W to be placed. Meanwhile, the locking member 45 of the stopper device 40 is advanced and retracted. Then, after the locking member 45 is moved back and forth to a predetermined position, the clamping screw 49a is rotated to fix the locking member 45. The push rod 29 of the pusher device 25 is automatically adjusted according to the outer diameter of the workpiece W input to the control device 50.

  Next, the workpiece W is placed on the rotary table 16 with the outer peripheral surface thereof in contact with the ends of the pressing body 31 and the locking member 45. As a result, as shown in FIG. 12, the center M2 of the workpiece W is placed at a position shifted by a predetermined amount with respect to the center M1 of the rotary table 16. An example of a method for placing the workpiece W on the rotary table 16 is a method of automatically placing the workpiece W on the rotary table 16 using a workpiece input device as appropriate.

  Next, the reference value determination unit 51 executes a reference value determination process to determine a reference value.

  Specifically, in a state where the outer peripheral surface of the workpiece W is in contact with the pressing body 31 of the push rod 29, the reference value determining unit 51 acquires the displacement amount detected by the displacement detector 32, and the acquired displacement The amount is determined as a reference value.

  Next, after the workpiece W is fixed on the turntable 16 by the attracting action by electromagnetic force, the shake maximum phase determining unit 53 executes the shake maximum phase determining process, and the phase of the turntable 16 at which the workpiece W shake is maximized. To decide.

  That is, first, the push rod 29 is moved backward to a position where the pressing body 31 does not contact the workpiece W when the rotary table 16 is rotated. Next, the rotary table 16 is rotated in the direction of arrow D in FIG. 12, the displacement detector 32 acquires the displacement at any time, and the position of the rotary table 16 detected by the phase detector 23 when the displacement turns from increasing to decreasing is obtained. The phase is set to the temporary maximum shake phase, and then the turntable 16 is rotated in the direction of arrow C in FIG. 12. Similarly, the turntable detected by the phase detector 23 when the displacement turns from increasing to decreasing. The 16 phases are assumed to be the temporary maximum shake phase. Then, an intermediate phase between the two temporary maximum shake phases is determined as the maximum shake phase.

  In this way, the phase when the rotary table 16 is rotated in both directions is set as the temporary maximum shake phase, and the intermediate phase between these two temporary maximum shake phases is set as the maximum shake phase. It is possible to determine the maximum shake phase closer to the original value than when the phase at the time of rotation is the maximum shake phase.

  Next, the shake amount calculation process is executed by the shake amount calculation unit 52 to calculate the shake amount of the workpiece W.

  Specifically, first, the rotary table 16 is rotated in the direction of arrow C in FIG. 12, and the maximum value of the displacement and the maximum value of the displacement are detected by the displacement detector 32 in a state where the rotary table 16 is rotated. The displacement value at a phase shifted by 180 ° from the obtained phase is acquired. Then, the shake amount of the workpiece W is calculated by dividing the sum of these two values by 2.

  In order to shorten the time required for the centering operation, the rotation direction of the rotary table 16 in the deflection amount calculation process is the maximum value of the displacement and the maximum value of the displacement without rotating the work W once. It is preferable that the displacement value in a phase shifted by 180 ° from the phase to be obtained can be obtained.

  Thereafter, the centering process is executed to center the workpiece W.

  Specifically, first, the rotary table 16 is rotated in the direction of arrow D in FIG. 12, and the determined maximum shake phase of the rotary table 16 is matched with the phase facing the push rod 29 of the pusher device 25. Next, after releasing the workpiece W, the push rod 29 is advanced to a position where the displacement detected by the displacement detector 32 becomes the reference value, and is further advanced by the calculated amount of deflection. Thereby, the workpiece W is centered.

  Then, after executing the centering process, the maximum shake phase is determined again, the shake amount of the workpiece W is calculated, and if the shake amount is not within the preset range, the centering process is performed in the same manner. And the three processes are repeatedly executed until the shake amount falls within the set range, or until the number of repetitions of the shake maximum phase determination process, the shake amount calculation process, and the centering process reaches a predetermined number.

  As described above, according to the vertical grinding machine 1 including the centering device 15 of this example, the centering operation of the workpiece W is automatically performed under the control of the control device 50. Further, in this example, the workpiece W is mounted in a state in which the distal end portion of the locking member 45 in the stopper device 40 is set at a position that is more distant from the rotation center of the rotary table 16 than the radius of the workpiece W. Therefore, when the centering is completed, a gap is secured between the tip of the locking member 45 and the outer peripheral surface of the workpiece W. Therefore, when placing the workpiece W on the rotary table 16, it is not necessary to perform an operation for attaching the stopper device 40 itself, and it is not necessary to perform an operation for removing the workpiece after the centering is completed. The replacement of W can be easily performed, and the complexity in the centering operation can be eliminated. Further, by adjusting the position of the locking member 45, it is possible to limit the amount of misalignment and reduce the time required for the centering operation.

  Furthermore, since the displacement detector 32 is provided in the pusher device 25, it is not necessary to provide a separate drive mechanism for the displacement detector, and the entire device can be made compact.

  As mentioned above, although one Embodiment of this invention was described, the specific aspect which this invention can take is not limited to this at all.

  In the above example, the pusher device 25 and the stopper device 40 are arranged with an interval of approximately 90 °. However, the present invention is not limited to this, and the interval between the pusher device 25 and the stopper device 40 is as follows. What is necessary is just to set suitably.

  In the above example, the amount of displacement detected by the displacement detector 32 is determined as the reference value while the pressing body 31 is in contact with the outer peripheral surface of the workpiece W. However, the present invention is not limited to this. is not. For example, the displacement detection is performed when the push rod 29 is advanced toward the workpiece W while the workpiece W is fixed on the rotary table 16 by an adsorption action by electromagnetic force, and the load of the drive motor 26 reaches a predetermined value. The displacement detected by the device 32 may be determined as a reference value.

DESCRIPTION OF SYMBOLS 1 Vertical grinding machine 2 Bed 3 Column 5 Feeder 10 Grinding wheel base 11 Grinding wheel 15 Centering device 16 Rotary table 20 Rotation drive mechanism 23 Phase detector 25 Pusher device 26 Drive motor 29 Push rod 32 Displacement detector 33 Feed screw 35 Housing 40 Stopper device 41 Base 42 Supporting portion 45 Locking member 49 Clamper 50 Control device 51 Reference value determining portion 52 Swing amount calculating portion 53 Swing maximum phase determining portion 54 Rotation drive mechanism control portion 55 Pusher device control portion 56 Main control portion W Work

Claims (4)

An apparatus for centering a workpiece mounted on a rotary table,
A disk-shaped rotary table on which a workpiece is attached;
A rotation drive mechanism for rotating the rotary table about an axis;
A phase detection mechanism for detecting the phase of the rotary table;
A pusher mechanism provided with an axial pressing member that advances and retreats along the normal direction of the rotary table, and is disposed outward of the normal direction with respect to the rotary table;
A locking member that contacts the outer peripheral surface of the work is provided at a position farther from the rotation center of the rotary table than the work radius, and is disposed outwardly in the normal direction with respect to the rotary table. A stopper mechanism;
A displacement detection mechanism that is arranged in parallel at the tip of the pressing member and detects the displacement in the normal direction of the workpiece on the rotary table;
A control device for controlling the operation of the rotation drive mechanism and the pusher mechanism,
The controller is
A reference value is determined based on the displacement detected by the displacement detection mechanism, the rotation table is rotated by controlling the operation of the rotation drive mechanism, and the rotation table detected by the detected displacement and the phase detection mechanism. Determining the phase of the rotary table that maximizes the workpiece deflection based on the phase of the workpiece, and calculating the workpiece deflection based on the displacement detected by the displacement detection mechanism,
The operation of the rotary drive mechanism is controlled to rotate the rotary table, the phase of the rotary table at which the calculated workpiece deflection is maximized is made to coincide with the phase facing the tip of the pressing member, and the pusher mechanism After controlling the operation to move the pushing member to a position where the displacement detected by the displacement detecting mechanism becomes the reference value, the pushing member is advanced toward the workpiece, and the workpiece is moved by the amount of deflection. A centering device characterized by performing a process of moving only. The controller is
A reference value determination unit that determines a reference value based on the displacement detected by the displacement detection mechanism;
The workpiece displacement detected by the displacement detection mechanism and the phase of the rotary table detected by the phase detection mechanism are acquired, and the deflection of the workpiece is maximized based on the acquired displacement of the workpiece and the phase of the rotary table. A maximum runout phase determination unit that determines the phase of the rotary table;
A displacement amount calculating unit that obtains a displacement of the workpiece detected by the displacement detection mechanism, and calculates a maximum deflection amount of the workpiece based on the obtained displacement of the workpiece;
A reference value determination process for determining a reference value based on the displacement detected by the displacement detection mechanism;
Based on the displacement of the workpiece and the phase of the rotary table, the maximum shake phase determination process for determining the phase of the rotary table that maximizes the shake amount;
In a state in which the rotation table is rotated by controlling the operation of the rotation drive mechanism, the displacement detection mechanism detects the displacement of the workpiece, and calculates the maximum deflection amount of the workpiece based on the detected workpiece displacement. When,
The operation of the rotation drive mechanism is controlled to rotate the rotary table, the determined maximum deflection phase is matched with the phase facing the tip of the pressing member, and the operation of the pusher mechanism is controlled, A core that moves the pressing member to the position where the displacement detected by the displacement detection mechanism becomes the reference value, then advances the pressing member toward the workpiece, and moves the workpiece by the maximum deflection amount. The centering apparatus according to claim 1, wherein a centering process is performed.   The shake maximum phase determination process, the shake amount calculation process, and the centering process are repeatedly executed until the shake amount of the workpiece falls within a predetermined range or the number of repetitions of the three processes reaches a predetermined number. The centering device according to claim 2.   The maximum deflection phase determination unit recognizes the phase at the time when the displacement of the workpiece detected by the displacement detection mechanism turns from increasing to decreasing with the rotating table rotated in one direction, and the rotating table. , In the reverse direction, the phase when the detected displacement of the workpiece changes from increasing to decreasing is recognized, and the phase between these two recognized phases is the rotation that maximizes the deflection of the workpiece. 4. The centering device according to claim 2, wherein a process for determining the phase of the table is executed.

Images