JP6062447B2 - Wear diagnostic system - Google Patents

Description

  The present invention relates to a wear diagnosis system for diagnosing wear on a sliding interface of a slide feed mechanism used in a machine tool or the like.

  As shown in Patent Document 1, a wedge-shaped razor (giving) is inserted in a gap between a lower slide (fixed side member) and an upper slide (moving side member) of a machine tool. The razor is attached to the upper slide. The sliding interface is formed between the sliding surface of the lower slide and the sliding surface of the razor. Lubricating oil is supplied to the sliding interface. That is, the sliding surface of the lower slide and the sliding surface of the upper slide are both covered with the oil film.

  However, an excessive load may be applied to the sliding interface due to variations in workpiece hardness, workpiece dimensional variations before processing, processing errors, and the like. In this case, the oil film breaks.

  Here, the sliding surface of the lower slide is quenched and polished. For this reason, the sliding surface of the lower slide is hard. On the other hand, the sliding surface of the razor is not quenched. For this reason, the sliding surface of a razor is soft.

  Therefore, when the oil film is cut and the sliding surface of the lower slide and the sliding surface of the razor are in direct sliding contact, the sliding surface of the razor is preferentially worn. When the sliding surface of the razor is worn, a gap is generated between the sliding surface of the lower slide and the sliding surface of the razor. For this reason, backlash occurs in the movement of the upper slide relative to the lower slide. Here, a tool is attached to the upper slide via a tool post. The workpiece is machined with a tool. Therefore, when play occurs in the movement of the upper slide, the position of the cutting edge of the tool with respect to the work is shifted by the amount of play. As a result, a dimensional error occurs in the workpiece after processing.

  In this case, the play can be eliminated by adjusting the amount of insertion of the razor (the amount of driving of the wedge) with respect to the gap between the lower slide and the upper slide. Specifically, when the insertion amount of the razor with respect to the gap between the lower slide and the upper slide is increased, the gap between the sliding surface of the lower slide and the sliding surface of the razor is reduced. For this reason, play can be eliminated.

JP 2010-52057 A

  As described above, when the sliding surface of the razor is worn, a dimensional error occurs in the workpiece after processing. For this reason, it is necessary to periodically diagnose the wear of the sliding surface of the razor. However, conventionally, the diagnosis of wear on the sliding surface of a razor has not been performed so much.

  That is, even if a dimensional error occurs in the workpiece, if the dimensional error is small, the workpiece can be machined by absorbing the dimensional error by a control method such as correcting the tool trajectory.

  Further, the cause of the dimensional error of the workpiece is not limited to the wear of the sliding surface of the razor. For example, a dimensional error may occur in the workpiece due to wear of the cutting edge of the tool, displacement of the workpiece, or the like. For this reason, even if a dimensional error occurs in the workpiece, the operator does not specify the cause only by the wear of the sliding surface of the razor.

  The razor is inserted in a gap between the lower slide and the upper slide. That is, the razor is arranged in a place where it is difficult for an operator to approach in the machine tool. For this reason, the wear diagnosis work is complicated.

  For these reasons, conventionally, the diagnosis of wear on the sliding surface of a razor has not been performed so much.

  However, if the wear on the sliding surface of the razor is left unattended, the control method cannot absorb the dimensional error of the workpiece after processing. In addition, troubles are likely to occur in parts such as a razor, a ball screw that drives the upper slide, an upper slide, and a lower slide.

  Accordingly, an object of the present invention is to provide a wear diagnostic system that can easily diagnose wear on a sliding interface.

  (1) In order to solve the above-described problem, the wear diagnosis system of the present invention includes a fixed portion having a lower slide, a moving portion having an upper slide that slides relative to the lower slide, and a drive that drives the upper slide. A device, a razor attached to the upper slide, inserted into a gap between the upper slide and the lower slide, and forming a sliding interface with the lower slide; and when the upper slide slides And a control for diagnosing wear of the sliding interface on the basis of a change in the amount of electricity related to the load of the driving device due to the contact of the moving unit with the corresponding contacting portion. And a device.

When the moving part comes into contact with the contact part, the amount of electricity related to the load of the driving device changes. According to the wear diagnosis system of the present invention, it is possible to diagnose wear on the sliding interface based on the change in the amount of electricity. For this reason, wear of the sliding interface can be easily diagnosed.

  In addition, since wear on the sliding interface can be easily diagnosed, for example, wear on the sliding interface is diagnosed in a preventive maintenance manner before a failure occurs in parts such as the lower slide, upper slide, and razor. be able to.

  (2) Preferably, in the configuration of (1), the driving device is a motor having an encoder, and the contact portion is a stopper with which the upper slide contacts to determine the origin of the encoder. It is better to have a configuration.

  In a machine tool, it is necessary to determine the origin of the encoder (that is, the movement reference position of the upper slide) before actual operation. For this reason, a process of intentionally bringing the upper slide into contact with the stopper is performed before actual operation. That is, a stopper for determining the origin is arranged in advance in the machine tool. In this regard, according to the present configuration, the existing stopper is used for diagnosis of wear on the sliding interface. For this reason, the wear diagnosis function can be easily added to the existing machine tool.

  (3) Preferably, in the configuration of the above (1) or (2), the control device sets the moving portion to the contact portion in an initial state in which the lower slide and the upper slide are set. In the initial state storage step of storing the change in the amount of electricity when the contact is made as initial data, and when the moving part is brought into contact with the corresponding contact part in a state after the initial state in time series A diagnosis step for diagnosing the wear of the sliding interface by comparing the change in the amount of electricity with the initial data, and a notification step for notifying the operator of the diagnosis result in the diagnosis step It is better to have a configuration.

  Here, “the state in which the lower slide and the upper slide are set” means that the lower slide, the upper slide, and the razor, which are the components of the slide feed mechanism, are preset standards for the operating accuracy, starting torque, and the like of the upper slide. The state that is assembled so as to enter. For example, it refers to a state after performance inspection of a machine tool including the slide feed mechanism is completed, before actual operation, or before actual production.

  According to this configuration, the control device executes the initial state storage process, the diagnosis process, and the notification process. In the initial state storing step, the control device causes the moving part to abut on the abutting part. And the control apparatus memorize | stores the data relevant to the change of the electric quantity at this time as initial data. In the diagnosis process, the control device causes the moving part to abut on the abutting part. Then, the change in the amount of electricity at this time is compared with the stored initial data. In the notification step, the control device notifies the operator of the diagnosis result.

  According to this configuration, the wear of the sliding interface can be diagnosed by comparing the initial data with the change in the amount of electricity at the time of diagnosis. In addition, the operator can be notified of the diagnosis result. For this reason, the operator can easily confirm the timing for adjusting the insertion amount of the razor with respect to the gap between the upper slide and the lower slide.

  (4) Preferably, in the configuration of (3) above, a display device having a screen is electrically connected to the control device, and the control device displays the diagnosis result on the screen in the notification step. It is better to display related items. According to this configuration, the operator can visually check the diagnosis result via the screen.

  (5) Preferably, in the configuration of (3) or (4), the control device moves the moving unit stepwise with respect to the abutting unit via the driving device in the diagnosis step. It is better to make it the structure to make.

  When the moving part is brought into contact with the contact part, the amount of electricity changes. However, when the processing speed of the control device is low, it is difficult to confirm a change in the amount of electricity if the moving unit is moved in a slope shape (gradually). In this regard, according to the present configuration, the moving unit is moved stepwise (stepwise). For this reason, even if the processing speed of the control device is slow, it is easy to confirm the change in the amount of electricity.

  ADVANTAGE OF THE INVENTION According to this invention, the wear diagnostic system which can diagnose the abrasion of a sliding interface easily can be provided.

FIG. 1 is an external perspective view of a CNC lathe provided with the wear diagnosis system of the first embodiment. FIG. 2 is an internal perspective view of the CNC lathe. 3 is an enlarged left side view of FIG. FIG. 4 is a perspective view of the slide feed mechanism. FIG. 5 is a cross-sectional view in the left-right direction of the slide feed mechanism. 6 is a cross-sectional view in the VI-VI direction of FIG. FIG. 7 is an exploded perspective view of the slide feed mechanism. FIG. 8 is an exploded perspective view of the slide on the Z axis and the razor portion. FIG. 9 is a block diagram of a CNC lathe provided with the wear diagnosis system of the first embodiment. FIG. 10A is a schematic cross-sectional view of the slide feeding mechanism in the previous period of the initial state storing step of the wear diagnosis method. FIG. 10B is a schematic cross-sectional view of the slide feeding mechanism in the latter stage of the same process. FIG. 11 is a schematic graph showing a change in load current of the Z-axis motor in the same process. FIG. 12 is a flowchart after the diagnostic preparation step of the wear diagnostic method. FIG. 13 is a schematic diagram of a screen at the time of automatic / manual selection. FIG. 14 is a schematic diagram of a screen when selecting diagnosis execution / non-execution. FIG. 15A is a schematic cross-sectional view of the slide feeding mechanism in the previous period of the diagnosis process of the wear diagnosis method. FIG. 15B is a schematic cross-sectional view of the slide feed mechanism in the middle stage of the same process. FIG. 15C is a schematic cross-sectional view of the slide feed mechanism in the latter stage of the process. FIG. 16 is a schematic graph showing a change in load current of the Z-axis motor in the same process. FIG. 17A is a schematic cross-sectional view of the slide feed mechanism in the previous period of the diagnosis process of the wear diagnosis method. FIG. 17B is a schematic cross-sectional view of the slide feed mechanism in the middle stage of the same process. FIG. 17C is a schematic cross-sectional view of the slide feed mechanism in the latter stage of the process. FIG. 18 is a schematic graph showing a change in load current of the Z-axis motor in the same process. FIG. 19 is a schematic diagram of a screen at the time of normal notification. FIG. 20 is a schematic diagram of a screen at the time of abnormality notification. FIG. 21 is a schematic graph showing a change in the load current of the Z-axis motor in the initial state storing step of the wear diagnosis method executed by the wear diagnosis system of the second embodiment. FIG. 22 is a schematic graph showing a change (No. 1) in the load current of the Z-axis motor in the diagnosis step of the same method. FIG. 23 is a schematic graph showing a change (No. 2) in the load current of the Z-axis motor in the diagnosis step of the same method. FIG. 24 is an internal perspective view of a CNC lathe provided with the wear diagnosis system of the third embodiment.

1: CNC lathe.
2: control device, 20: storage unit, 21: calculation unit, 22: input / output interface.
30: Whole cover, 300: Automatic door, 31: Ball screw part, 310: Ball screw, 311: Nut, 32: Razor part, 320: Razor, 321: Collar, 322: Bracket, 323: Bolt, 33: Stopper part 330: stopper, 331: bracket, 332: bolt.
4: Tool table, 40: Tool post, 41: Turret device, 42: Slide down on the X axis, 43: Slide up on the Z axis (up slide), 43a: Slide body, 43b: Back plate, 430: Guided groove, 432 : Power transmission part, 44: Z-axis lower slide (lower slide), 441: Guide rib, 442: Ball screw housing part, 45X: X-axis motor, 45Z: Z-axis motor (motor), 46: X-axis upper slide.
6: spindle head, 60: main body, 61: spindle, 62: chuck (contact portion), 63C: spindle motor.
7: Bed, 70: Inclined part.
8: display device, 80: screen, 81a: automatic start button, 81b: manual start button, 82a: diagnosis execution button, 82b: diagnosis non-execution button, 83: confirmation button, 84: confirmation button.
9: Wear diagnosis system, 90: fixed part, 91: moving part.
A1: inner surface, A2: outer surface, A3: sliding surface, A4: sliding surface, B1 to B4: sliding interface, C1: sliding interface, D1: sliding interface, T: tool (moving part), T1: Cutting edge, W: workpiece, Z1: axis, t0: time, t1: time, Δt1: time, Δt2: time, ΔP1: deviation amount.

  Hereinafter, embodiments of the wear diagnosis system of the present invention will be described.

<First embodiment>
[Configuration of CNC lathe]
First, the configuration of a CNC lathe provided with the wear diagnosis system of this embodiment will be described. FIG. 1 shows an external perspective view of a CNC lathe provided with the wear diagnosis system of the present embodiment. FIG. 2 shows an internal perspective view of the CNC lathe.

  As shown in FIGS. 1 and 2, the CNC lathe 1 includes a control device (not shown), an entire cover 30, a ball screw part 31, a razor part (not shown), a stopper part (not shown), A tool table 4, a headstock 6, a bed 7, a display device 8, and a wear diagnosis system 9 are provided.

(Whole cover 30, display device 8)
As shown in FIG. 1, the entire cover 30 constitutes an outer shell of the CNC lathe 1. The entire cover 30 includes an automatic door 300 on the front surface. The display device 8 is disposed on the front surface of the entire cover 30. The display device 8 includes a screen 80. The screen 80 is a touch panel.

(Bed 7, headstock 6)
As shown in FIG. 2, the bed 7 is disposed on the floor of the factory. An inclined portion 70 is disposed behind the upper surface of the bed 7. The inclined portion 70 has a slope shape that descends from the rear to the front.

  The headstock 6 is disposed on the upper left side of the bed 7. The headstock 6 includes a main body 60, a main shaft 61, and a chuck 62. The main body 60 is disposed on the upper surface of the bed 7. The main shaft 61 protrudes from the right surface of the main body 60 to the right side. The main shaft 61 extends in the left-right direction. The main shaft 61 is rotatable around its own axis. The chuck 62 is disposed at the right end of the main shaft 61. A workpiece W is fixed to the chuck 62 so as to be detachable.

(Tool stand 4)
FIG. 3 is a transparent enlarged left side view of FIG. As shown in FIGS. 2 and 3, the tool rest 4 includes a tool post 40, a turret device 41, an X-axis upper slide 46, an X-axis lower slide 42, a Z-axis upper slide 43, and a Z-axis lower slide. 44. The Z-axis upper slide 43 is included in the concept of the “upper slide” of the present invention. The Z-axis lower slide 44 is included in the concept of the “lower slide” of the present invention.

  FIG. 4 is a perspective view of a Z-axis lower slide, a Z-axis upper slide, a ball screw portion, a razor portion, and a stopper portion (hereinafter referred to as “slide feed mechanism” as appropriate). FIG. 5 is a cross-sectional view in the left-right direction of the slide feed mechanism. FIG. 6 is a cross-sectional view in the VI-VI direction of FIG. FIG. 7 shows an exploded perspective view of the slide feed mechanism. FIG. 8 is an exploded perspective view of the slide on the Z axis and the razor portion.

  The Z-axis lower slide 44 is disposed on the inclined portion 70 on the upper surface of the bed 7. The Z-axis lower slide 44 extends in the left-right direction (the central axis direction of the main shaft 61 (Z-axis direction)). The Z-axis lower slide 44 includes a pair of guide ribs 441 and a ball screw accommodating portion 442. As shown in FIG. 6, the pair of guide ribs 441 are disposed on both sides of the front lower-rear upper direction (X-axis direction) of the ball screw accommodating portion 442.

  A Z-axis motor 45Z is disposed on the left end surface of the Z-axis lower slide 44. The Z-axis motor 45Z is a servo motor with an encoder. The Z-axis motor 45Z is included in the concept of the “motor” of the present invention.

  The Z-axis upper slide 43 is movable in the left-right direction with respect to the Z-axis lower slide 44. As shown in FIG. 6, the Z-axis upper slide 43 includes a slide body 43a and a pair of back plates 43b. A power transmission unit 432 is integrally formed on the lower surface of the slide body 43a. The power transmission part 432 is accommodated in the ball screw accommodation part 442. The pair of back plates 43b are disposed on both sides in the front lower-rear upper direction of the slide main body 43a. A pair of guided grooves 430 is defined in the Z-axis slide 43 by the slide main body 43a and the pair of back plates 43b. Of the pair of guided grooves 430, the rear upper guided groove 430 is in sliding contact with the rear upper guide rib 441 from the rear upper direction. Note that a razor 320 (described later) is interposed in the gap between the front lower guided groove 430 and the front lower guide rib 441.

  As shown in FIG. 3, the turret device 41 is an angle indexing device. The turret device 41 is fixed to the upper surface of the X-axis upper slide 46. The tool post 40 is disposed on the left surface of the turret device 41. A total of ten holders (not shown) are arranged on the tool post 40 at a distance of 36 °. The tool post 40 can be rotated by 36 ° in units of holders by a turret device 41. A tool T is assigned to each of the ten holders of the tool post 40. When the main shaft 61 rotates, the cutting edge T1 of an arbitrary tool T comes into sliding contact with the outer peripheral surface of the workpiece W. The tool T cuts the outer peripheral surface of the workpiece W by the sliding contact.

(Ball screw part, razor part, stopper part)
As shown in FIGS. 4 to 8, the ball screw portion 31 includes a ball screw 310, a nut 311, and a number of balls (not shown). The ball screw 310 extends in the left-right direction within the ball screw accommodating portion 442 of the Z-axis lower slide 44. The ball screw 310 is connected to the rotation shaft of the Z-axis motor 45Z. The ball screw 310 can rotate around its own axis by the driving force of the Z-axis motor 45Z. The nut 311 is mounted on the outer peripheral surface of the ball screw 310 via a large number of balls. As shown in FIGS. 6 and 7, the nut 311 is attached to the power transmission portion 432 of the Z-axis upper slide 43. When the ball screw 310 rotates about its own axis, the nut 311, that is, the Z-axis upper slide 43 moves in the left-right direction.

  As shown in FIGS. 4 to 8, the razor portion 32 includes a razor 320, a pair of collars 321, a bracket 322, and four bolts 323. As shown in FIG. 8, the bracket 322 is attached to the Z-axis upper slide 43. Specifically, the bracket 322 is attached to the left end surface of the front lower side of the slide body 43a of the Z-axis upper slide 43 by a pair of bolts 323 via a pair of collars 321 extending in the left-right direction. .

  The razor 320 is attached to the right surface of the bracket 322 by a pair of bolts 323. The razor 320 is inserted into a gap between the front lower guided groove 430 and the front lower guide rib 441. By adjusting the length of the pair of collars 321 in the left-right direction, the amount of razor 320 inserted into the gap can be adjusted.

  As shown in FIG. 5, the razor 320 has a wedge shape that is sharp on the right side (inside the gap). Specifically, as shown in FIGS. 6 and 8, the inner surface A1 of the front lower guided groove 430 is inclined with respect to the left-right direction (for example, (X-axis direction length / Z-axis direction length). In the direction of (S = 1/100)). The outer surface A2 of the razor 320 extends in the same direction as the inner surface A1. The sliding surface (outer surface) A3 of the front lower guide rib 441 extends in the left-right direction. A sliding surface (inner surface) A4 of the razor 320 extends in the same direction as the sliding surface A3.

  As shown by a thick line in FIG. 6, a slide that abuts from the Z-axis upper slide 43 and the Z-axis lower slide 44 from the Y-axis direction (the direction perpendicular to the Z-axis direction and the X-axis direction). Interfaces B1 to B4 are arranged. Further, a sliding interface C1 that contacts from the X-axis direction is disposed. In addition, a sliding interface D <b> 1 that contacts from the X-axis direction is disposed between the sliding surface A <b> 3 of the Z-axis lower slide 44 and the sliding surface A <b> 4 of the razor 320. Lubricating oil (not shown) is supplied to each of these sliding interfaces B1 to B4, C1, and D1.

  The sliding surface of the Z-axis lower slide 44 is quenched and polished. For this reason, the sliding surface of the Z-axis lower slide 44 is hard. On the other hand, the sliding surface of the Z-axis upper slide 43 and the sliding surface of the razor 320 are not quenched. For this reason, the sliding surface of the Z-axis upper slide 43 and the sliding surface of the razor 320 are soft. Therefore, when the lubricating oil runs out during the sliding of the Z-axis upper slide 43, the sliding surface of the Z-axis upper slide 43 and the sliding surface of the razor 320 are mainly worn.

  As shown in FIGS. 4 to 8, the stopper portion 33 includes a stopper 330, a bracket 331, and two bolts 332. As shown in FIG. 7, the bracket 331 is attached to the Z-axis lower slide 44. Specifically, the bracket 331 is attached to the left end surface on the rear upper side of the Z-axis lower slide 44 by a pair of bolts 332. The stopper 330 protrudes from the right surface of the bracket 331 to the right side. The stopper 330 has a cylindrical shape. When the Z-axis upper slide 43 moves to the left side, the stopper 330 can come into contact with the rear upper left end surface of the Z-axis upper slide 43.

(Control device)
FIG. 9 shows a block diagram of a CNC lathe provided with the wear diagnosis system of the present embodiment. The control device 2 includes a storage unit 20, a calculation unit 21, and an input / output interface 22. The control device 2 is electrically connected to the screen 80, the X-axis motor 45X, the Z-axis motor 45Z, and the main shaft motor 63C. The X-axis motor 45X can drive the X-axis upper slide 46 in the front lower-rear upper direction. The Z-axis motor 45Z can drive the Z-axis upper slide 43 in the left-right direction. The main shaft motor 63C can rotate the main shaft 61 around its own axis.

(Wear diagnosis system 9)
As shown in FIGS. 1 to 9, the wear diagnosis system 9 includes a fixed portion 90, a moving portion 91, a Z-axis motor 45Z, a ball screw portion 31, a razor portion 32, a stopper portion 33, and a control device. 2 and a display device 8. The fixing unit 90 includes a Z-axis lower slide 44. The moving unit 91 includes a Z-axis upper slide 43. As described above, the wear diagnosis system 9 is incorporated in the CNC lathe 1.

[Movement when machining a CNC lathe]
Next, the movement of the CNC lathe equipped with the wear diagnosis system of the present embodiment during workpiece machining will be briefly described. First, as shown in FIGS. 2 and 3, the workpiece W is fixed to the chuck 62. Next, as shown in FIG. 9, the control device 2 drives the spindle motor 63C. When the main shaft motor 63 </ b> C is driven, the main shaft 61, that is, the work W rotates around the main shaft 61. Then, as shown in FIG. 9, the control device 2 drives the X-axis motor 45X and the Z-axis motor 45Z. Then, the cutting edge T1 of the tool T is moved to a predetermined processing point. At the machining point, the blade tip T1 is in sliding contact with the outer peripheral surface of the rotating workpiece W. Cutting is performed on the outer peripheral surface of the workpiece W by the sliding contact. Cutting is performed while appropriately switching the ten tools T in accordance with the processed surface of the workpiece W. The workpiece W that has been processed is removed from the chuck 62 and conveyed to a subsequent process. On the other hand, a new workpiece W is mounted on the chuck 62 that has become empty.

[Wear diagnosis method]
Next, a wear diagnosis method executed by the wear diagnosis system of the present embodiment will be described. The wear diagnosis method includes an initial state storage process, a diagnosis preparation process, a diagnosis process, a notification process, and a rediagnosis process.

(Initial state storage process)
This process is executed immediately after the CNC lathe 1 is turned on for the first time. In this process, the initial state (the Z-axis lower slide 44, the Z-axis upper slide 43, the razor part 32 is assembled so that the operation accuracy, starting torque, etc. of the Z-axis upper slide 43 are within preset standards. The origin of the encoder of the Z-axis motor 45Z is determined. In addition, the load current of the Z-axis motor 45Z is measured. The encoder origin and load current changes are stored as initial data. The load current is included in the concept of “electric quantity” of the present invention.

  FIG. 10A shows a schematic cross-sectional view of the slide feed mechanism in the previous period of the initial state storing step of the wear diagnosis method. FIG. 10B shows a schematic cross-sectional view of the slide feed mechanism in the latter stage of the same process. FIG. 11 shows changes in the load current of the Z-axis motor in the same process. In FIGS. 10A and 10B, the slide feed mechanism shown in FIG. 5 is shown deformed.

  First, the calculating part 21 of the control apparatus 2 shown in FIG. 9 drives the Z-axis motor 45Z. At this time, the calculation unit 21 intermittently applies current to the Z-axis motor 45Z. Therefore, as shown in FIG. 10A, the Z-axis upper slide 43 approaches the stopper 330 while moving stepwise (moving (for example, 10 μm) and stopping alternately).

  In the initial state, the Z-axis upper slide 43 and the razor 320 are not yet worn. The insertion amount of the razor 320 with respect to the gap between the Z-axis upper slide 43 and the Z-axis lower slide 44 is set to an appropriate amount. For this reason, as shown in FIG. 10B, when the Z-axis upper slide 43 contacts the stopper 330, the load current increases. As shown in FIG. 11, at time t0 when the load current reaches a predetermined value a0 (previously stored in the storage unit 20 shown in FIG. 9), the calculation unit 21 applies the Z-axis upper slide 43 to the stopper 330. It is determined that it is the time of contact. Then, the calculation unit 21 stores the encoder position at the time t0 in the storage unit 20 as the origin (the operation reference position of the Z-axis upper slide 43). Moreover, the calculating part 21 stores the change of the load current shown in FIG.

  Further, the operator stores in the storage unit 20 a time when wear diagnosis will be performed in the future, that is, a diagnosis time (for example, six months later), via the touch panel of the screen 80 shown in FIG.

(Diagnosis preparation process)
FIG. 12 shows a flowchart after the diagnostic preparation step of the wear diagnostic method. FIG. 13 shows a schematic diagram of a screen at the time of automatic / manual selection. FIG. 14 shows a schematic diagram of a screen at the time of diagnosis execution / non-execution selection.

  When the operator activates the CNC lathe 1 (S1 in FIG. 12 (step 1; the same applies hereinafter)), the calculation unit 21 shown in FIG. 9 brings the screen 80 into the state shown in FIG. 13 (S2 in FIG. 12). That is, an automatic start button 81a and a manual start button 81b are displayed on the screen 80.

  When the operator selects the manual start button 81b, the calculation unit 21 shown in FIG. 9 executes wear diagnosis described later (S5 in FIG. 12).

  On the other hand, when the operator selects the automatic start button 81a, the calculation unit 21 shown in FIG. 9 displays the driving time of the CNC lathe 1 up to the present time and the diagnosis time stored in the storage unit 20 in the initial state storage step. Are compared (S3 in FIG. 12).

  As a result of the comparison, when the driving time of the CNC lathe 1 up to the present does not coincide with the diagnosis time, the CNC lathe 1 shown in FIG. 2 starts production (S10 in FIG. 12). That is, the CNC lathe 1 starts machining the workpiece W.

  On the other hand, as a result of comparison, when the driving time of the CNC lathe 1 up to the present matches the diagnosis time, the calculation unit 21 shown in FIG. 9 switches the screen 80 to the state shown in FIG. 14 (FIG. 12). S4). That is, a diagnosis execution button 82a and a diagnosis non-execution button 82b are displayed on the screen 80.

(Diagnosis process)
When the operator selects the diagnosis non-execution button 82b (see FIG. 14) in S4 of FIG. 12, the CNC lathe 1 shown in FIG. 2 starts production (S10 of FIG. 12). That is, the CNC lathe 1 starts machining the workpiece W.

  On the other hand, when the operator selects the diagnosis execution button 82a (see FIG. 14) in S4 of FIG. 12, the calculation unit 21 shown in FIG. 9 executes wear diagnosis (S5 of FIG. 12). That is, when the driving time of the CNC lathe 1 (driving time from the first power-on) becomes longer, the wear amount of the sliding surface of the Z-axis upper slide 43 and the sliding surface of the razor 320 shown in FIGS. It may have become. That is, there is a possibility that play is generated at the sliding interfaces C1 and D1. Therefore, in this step, the load current of the Z-axis motor 45Z is measured as in the initial state storing step.

  First, the case where the axis Z1 of the Z-axis upper slide 43 is inclined in the clockwise direction of FIG. 5 with respect to the Z axis due to the backlash of the sliding interfaces C1 and D1 will be described.

  FIG. 15A is a schematic cross-sectional view of the slide feeding mechanism in the previous stage of the diagnosis process of the wear diagnosis method. FIG. 15B is a schematic cross-sectional view of the slide feed mechanism in the middle stage of the same process. FIG. 15C is a schematic cross-sectional view of the slide feeding mechanism in the latter stage of the process. FIG. 16 shows a change in the load current of the Z-axis motor in the same process. 15 (a), 15 (b), and 15 (c), the slide feed mechanism shown in FIG. 5 is shown deformed. Further, the backlash generated at the sliding interfaces C1 and D1 is exaggerated. If the slide feed mechanism continues to operate while the play of the sliding interfaces C1 and D1 is enlarged, a large number of balls of the ball screw portion 31 are worn, and FIG. 15 (a), FIG. 15 (b), FIG. As shown in FIG. 3, the play progresses to a state in which a backlash occurs between the ball screw 310 and the nut 311. In this case, first, the calculation unit 21 shown in FIG. 9 drives the Z-axis motor 45Z. At this time, the calculation unit 21 intermittently applies a current to the Z-axis motor 45Z as in the initial state storing step. For this reason, as shown to Fig.15 (a), the Z-axis upper slide 43 approaches the stopper 330, moving in step shape.

  Here, as shown by a thin line in FIG. 15B, if there is no backlash at the sliding interfaces C1 and D1, the Z-axis upper slide 43 is the origin of the encoder as in the initial state storing step. (Stored in the storage unit 20 shown in FIG. 9) and should contact the stopper 330. Therefore, as indicated by a thin line in FIG. 16, the load current should reach a predetermined value a0 at time t0 corresponding to the origin.

  However, play is generated at the sliding interfaces C1 and D1. For this reason, the axis Z1 of the Z-axis upper slide 43 is inclined clockwise with respect to the Z axis. Therefore, as shown in FIG. 15B, even if the encoder reaches the origin, the Z-axis upper slide 43 is not yet in contact with the stopper 330. Therefore, as shown in FIG. 16, the load current does not reach the predetermined value a0 even at time t0 corresponding to the origin.

  As shown in FIG. 15C, when the Z-axis upper slide 43 contacts the stopper 330 (at time t1 shown in FIG. 16), the load current reaches a predetermined value a0. Here, the time Δt1 between the times t0 and t1 shown in FIG. 16 is the deviation amount ΔP1 shown in FIG. 15C (the origin of the encoder in the contact state shown in FIG. 10B and the origin in FIG. 15C. Corresponding to the position of the encoder in the abutting state shown in FIG. 9 determines whether or not the adjustment of the insertion amount of the razor 320 with respect to the gap between the Z-axis upper slide 43 and the Z-axis lower slide 44 is necessary based on the time Δt1 ( S6 in FIG.

  Second, the case where the axis Z1 of the Z-axis upper slide 43 is tilted counterclockwise in FIG. 5 with respect to the Z axis due to the backlash of the sliding interfaces C1 and D1 will be described.

  FIG. 17A is a schematic cross-sectional view of the slide feeding mechanism in the previous stage of the diagnosis process of the wear diagnosis method. FIG. 17B is a schematic cross-sectional view of the slide feed mechanism in the middle stage of the same process. FIG. 17C is a schematic cross-sectional view of the slide feed mechanism in the latter stage of the process. FIG. 18 shows a change in the load current of the Z-axis motor in the same process. 17 (a), 17 (b), and 17 (c), the slide feed mechanism shown in FIG. 5 is shown deformed. Further, the backlash generated at the sliding interfaces C1 and D1 is exaggerated.

  First, the calculating part 21 shown in FIG. 9 drives the Z-axis motor 45Z. As shown in FIG. 17A, the Z-axis upper slide 43 approaches the stopper 330 while moving stepwise. As shown by a thin line in FIG. 17B, if there is no backlash at the sliding interfaces C1 and D1, the load current is predetermined at time t0 corresponding to the origin as shown by a thin line in FIG. The value a0 should be reached.

  However, play is generated at the sliding interfaces C1 and D1. For this reason, the axis Z1 of the Z-axis upper slide 43 is inclined counterclockwise with respect to the Z axis. Therefore, as shown in FIG. 17B, the Z-axis upper slide 43 is already in contact with the stopper 330 before the encoder reaches the origin.

  However, as shown in FIGS. 17B and 17C, the Z-axis upper slide 43 consumes the backlash of the sliding interfaces C1 and D1, and only tilts in the clockwise direction. For this reason, the change in the slope of the load current (first-order time differential value) is small.

  As shown in FIG. 17C, the Z-axis upper slide 43 and the Z-axis lower slide 44 abut on the right end of the sliding interface C1, and the razor 320 and the Z-axis lower slide 44 are on the left end of the sliding interface D1. When they come into contact (at time t1 shown in FIG. 18), the tilt of the Z-axis upper slide 43 is restricted. For this reason, the load current reaches a predetermined value a0. Here, the time Δt1 between the times t0 and t1 shown in FIG. 18 corresponds to the deviation amount ΔP1 shown in FIG. 17C (the origin of the encoder in the contact state shown in FIG. 10B and the origin in FIG. 17C. Corresponding to the position of the encoder in the abutting state shown in FIG. 9 determines whether or not the adjustment of the insertion amount of the razor 320 with respect to the gap between the Z-axis upper slide 43 and the Z-axis lower slide 44 is necessary based on the time Δt1 ( S6 in FIG.

(Notification process)
In this process, the result of wear diagnosis in the diagnosis process is notified to the operator. FIG. 19 shows a schematic diagram of a screen at the time of normal notification. FIG. 20 shows a schematic diagram of a screen at the time of abnormality notification.

  When it is determined in S6 of FIG. 12 that the adjustment of the insertion amount of the razor 320 is unnecessary, the calculation unit 21 switches the screen 80 to the state illustrated in FIG. 19 (S11 of FIG. 12). The operator presses the confirmation button 83 on the screen 80. The CNC lathe 1 shown in FIG. 2 starts production (S10 in FIG. 12). That is, the CNC lathe 1 starts machining the workpiece W.

  On the other hand, when it is determined in S6 of FIG. 12 that the insertion amount of the razor 320 needs to be adjusted, the computing unit 21 switches the screen 80 to the state shown in FIG. 20 (S7 of FIG. 12). The worker presses the confirmation button 84 on the screen 80 and executes the adjustment work of the insertion amount of the razor 320 (S8 in FIG. 12). Specifically, as shown in FIG. 8, the insertion amount of the razor 320 is adjusted so that the starting torque (load current) of the Z-axis upper slide 43 matches between the initial state and the adjusted insertion amount. Then, the used collar 321 is replaced with a new collar 321 having an appropriate lateral length so that the insertion amount can be maintained.

  After the adjustment work is completed, the calculation unit 21 switches the screen 80 to the state shown in FIG. When another diagnosis is unnecessary, the operator selects the diagnosis non-execution button 82b (S9 in FIG. 12). In this case, the CNC lathe 1 shown in FIG. 2 starts production (S10 in FIG. 12). That is, the CNC lathe 1 starts machining the workpiece W.

  On the other hand, when the operator selects the diagnosis execution button 82a in S9 of FIG. 12, the calculation unit 21 shown in FIG. 9 executes the diagnosis process and the notification process again.

  As shown in S3 and S4 of FIG. 12, after the start of production, the screen 80 shown in FIG. 9 switches to the state shown in FIG. 14 at every diagnosis time (for example, every six months). For this reason, the operator can recognize the time of wear diagnosis regularly and easily.

[Function and effect]
Next, the effect of the wear diagnostic system of this embodiment will be described. According to the wear diagnosis system 9 of this embodiment, as shown in FIGS. 11, 16, and 18, the wear of the sliding interfaces C1 and D1 can be diagnosed based on the change in the load current of the Z-axis motor 45Z. it can. For this reason, it is possible to easily diagnose the wear of the sliding interfaces C1 and D1.

  Further, since wear of the sliding interfaces C1 and D1 can be easily diagnosed, parts such as the Z-axis lower slide 44, the Z-axis upper slide 43, the razor 320, and the Z-axis motor 45Z are generated by the wear. Troubles between the slides (specifically, the Z-axis upper slide 43 with respect to the Z-axis lower slide 44) cause problems such as deformation of the Z-axis lower slide 44 and Z-axis upper slide 43 and damage to the ball screw portion 31. Before doing so, wear of the sliding interfaces C1 and D1 can be diagnosed in a preventive maintenance manner.

  Further, according to the wear diagnosis system 9 of the present embodiment, as shown in FIGS. 10 and 11, the initial state storage step also serves to determine the origin of the encoder of the Z-axis motor 45Z. For this reason, compared with the case where both work is performed separately, work man-hours can be reduced. Moreover, the existing stopper 330 is diverted for diagnosis of wear of the sliding interfaces C1 and D1. For this reason, the wear diagnosis function can be easily added to the existing CNC lathe 1.

  Further, according to the wear diagnosis system 9 of the present embodiment, as shown in FIG. 12, the control device 2 executes an initial state storage process, a diagnosis process, a notification process, and a rediagnosis process. For this reason, the wear of the sliding interfaces C1 and D1 can be diagnosed automatically and periodically. In addition, the operator can be notified of the diagnosis result. For this reason, the operator can easily confirm the timing for adjusting the insertion amount of the razor 320.

  Further, according to the wear diagnosis system 9 of the present embodiment, as shown in FIGS. 19 and 20, the control device 2 displays items related to the diagnosis result on the screen 80 in the notification process. For this reason, the operator can visually confirm the diagnosis result via the screen 80.

  Further, according to the wear diagnosis system 9 of the present embodiment, the Z-axis upper slide 43 is moved stepwise with respect to the stopper 330 as shown in FIGS. 11, 16, and 18. For this reason, even when the processing speed of the calculation unit 21 of the control device 2 is low, it is easy to confirm a change in the load current. In addition, since a rapid change in load current is unlikely to occur, it is difficult for the slide feed mechanism to be defective.

<Second embodiment>
The difference between the wear diagnosis system of this embodiment and the wear diagnosis system of the first embodiment is that the Z-axis slide is moved in a slope shape (gradually) with respect to the stopper. Here, only differences will be described.

  FIG. 21 shows a change in the load current of the Z-axis motor in the initial state storing step of the wear diagnosis method. FIG. 22 shows a change (No. 1) in the load current of the Z-axis motor in the diagnosis process of the same method. FIG. 23 shows a change (No. 2) in the load current of the Z-axis motor in the diagnosis process of the same method. 21 corresponds to FIG. 11, FIG. 22 corresponds to FIG. 16, and FIG. 23 corresponds to FIG. As in this embodiment, the Z-axis slide may be moved in a slope with respect to the stopper.

  The wear diagnostic system of the present embodiment and the wear diagnostic system of the first embodiment have the same operational effects with respect to the parts having the same configuration. Moreover, according to this embodiment, the change of load current can be measured more accurately. Further, the times t0 and t1 can be confirmed with higher accuracy.

<Third embodiment>
The difference between the wear diagnostic system of the present embodiment and the wear diagnostic system of the first embodiment is that the load on the Z-axis motor when the tool is brought into contact with the chuck in the initial state storage process, the diagnostic process, and the rediagnosis process. This is the point at which current is measured. Here, only differences will be described.

  FIG. 24 shows an internal perspective view of a CNC lathe provided with the wear diagnosis system of the present embodiment. Note that portions corresponding to those in FIG. 2 are denoted by the same reference numerals. As shown in FIG. 24, a change in load current of the Z-axis motor 45Z when the tool T is brought into contact with the chuck 62 may be measured in the initial state storage process, the diagnosis process, and the re-diagnosis process. Then, wear of the sliding interface may be diagnosed from the change in the load current. In the case of this embodiment, the tool T is included in the concept of the “moving part” of the present invention. Further, the chuck 62 is included in the concept of the “contact portion” of the present invention.

  The wear diagnostic system of the present embodiment and the wear diagnostic system of the first embodiment have the same operational effects with respect to the parts having the same configuration. Further, according to the present embodiment, it is possible to diagnose the wear of the sliding interface even when the stopper is not disposed.

<Others>
The embodiment of the wear diagnosis system of the present invention has been described above. However, the embodiment is not particularly limited to the above embodiment. Various modifications and improvements that can be made by those skilled in the art are also possible.

  The diagnostic method in the diagnostic process shown in S5 of FIG. 12 is not particularly limited. The diagnosis of wear may be executed from the change in load current in the vicinity of the origin of the encoder of the Z-axis motor 45Z. For example, by comparing the slope of the load current (first-order derivative of the load current) and the change rate of the slope of the load current (second-order derivative of the load current) in the initial state storage process and the diagnosis process, A diagnosis may be made.

  Further, the positions of the gaps shown in FIGS. 15 (a), 15 (b), 15 (c), 17 (a), 17 (b), and 17 (c) are not particularly limited. There may be uniform gaps at the sliding interfaces C1 and D1. Further, a gap may be generated only in one of the sliding interfaces C1 and D1.

  Also, the shape of the load current change curve when the play occurs is not limited to the shape of the load current change curve shown in FIGS. 16, 18, 22, and 23. That is, the shape of the change curve of the load current when the play occurs is as follows: the arrangement direction of the Z-axis upper slide 43 and the Z-axis lower slide 44, the position of the stopper 330, and the X-axis of the member mounted on the Z-axis upper slide 43 Depending on the direction, the weight balance in the Y-axis direction, the direction in which gravity acts, and the like. Similarly, the shape of the load current change curve in the initial state is not limited to the shape of the load current change curve shown in FIGS.

  However, when the shape of the load current change curve in the initial state is compared with the shape of the load current change curve when the play occurs, there is a difference. According to the wear diagnosis system of the present invention, wear diagnosis can be performed by paying attention to the difference.

  In the above-described embodiment, wear is diagnosed by detecting yawing generated from the gap in the X-axis direction between the Z-axis upper slide 43 and the Z-axis lower slide 44. However, the wear may be diagnosed by detecting pitching caused by a gap in the Y-axis direction between the Z-axis upper slide 43 and the Z-axis lower slide 44.

  In the above embodiment, the wear diagnosis is performed based on the change in the load current of the Z-axis motor 45Z. However, the wear diagnosis may be performed based on the change in the load voltage, torque, and the like.

  In the above embodiment, the wear diagnosis system of the present invention is used for adjusting the razor 320 between the Z-axis lower slide 44 and the Z-axis upper slide 43. However, the wear diagnosis system of the present invention may be used for adjusting the razor between the X-axis lower slide 42 and the X-axis upper slide 46.

  Further, the insertion position of the razor 320 is not particularly limited. For example, the razor 320 may be inserted into at least one of the sliding interfaces B1 to B4 and C1 shown in FIG. The number of razors 320 inserted is not particularly limited. For example, a pair of razors 320 may be inserted between the inner surface A1 and the sliding surface A3 shown in FIG.

  Moreover, the drive mechanism of the Z-axis upper slide 43 and the X-axis upper slide 46 is not particularly limited. For example, a linear motor may be used.

  Further, in S6 of FIG. 12, it may be determined whether or not the insertion amount of the razor 320 needs to be adjusted by comparing the time Δt1 with a predetermined threshold (threshold related to time). . Also, whether the amount of insertion of the razor 320 needs to be adjusted by calculating the amount of deviation ΔP1 from the time Δt1 and comparing the amount of deviation ΔP1 with a predetermined threshold (threshold for the amount of deviation). May be determined.

  A plurality of threshold values may be set. For example, regarding the time Δt1, two threshold values, a threshold value th1 and a threshold value th2 (> threshold value th1), may be set. Then, when time Δt1 <threshold value th1, S11 in FIG. 12 may be executed. In addition, when threshold value th1 ≦ time Δt1 <threshold value th2, a warning message (for example, “Razor wear is progressing. Please adjust the razor in the near future.”) ) May be displayed. If threshold value th2 ≦ time Δt1, S7 in FIG. 12 may be executed.

  In the above embodiment, the stopper 330 and the chuck 62 are used as the “contact portion” of the present invention. However, the contact portion is not particularly limited. When the Z-axis upper slide 43 slides with respect to the Z-axis lower slide 44, it is only necessary that the moving part can come into contact therewith. For example, the workpiece W, the main shaft 61, the entire cover 30 and the like may be used as the contact portion.

  Moreover, in the said embodiment, the Z-axis top slide 43 and the tool T were used as the "moving part" of this invention. However, the moving unit is not particularly limited. When the Z-axis upper slide 43 slides with respect to the Z-axis lower slide 44, it may be movable together with the Z-axis upper slide 43. For example, the X-axis lower slide 42, the X-axis upper slide 46, the turret device 41, the tool post 40, a holder for the tool T, and the like may be used.

  Further, the main axis direction of the CNC lathe 1 is not particularly limited. That is, the wear diagnosis system of the present invention may be incorporated in a horizontal lathe, a front lathe, and a vertical lathe. Further, the wear diagnosis system of the present invention may be incorporated in a milling machine, drilling machine, milling cell, or the like.

Claims (6)

A fixed part having a lower slide;
A moving unit having an upper slide that slides in a linear direction relative to the lower slide;
A driving device for driving the upper slide;
A razor attached to the upper slide, inserted into a gap between the upper slide and the lower slide, and forming a sliding interface with the lower slide;
An abutting portion with which the moving portion abuts when the upper slide slides;
A control device for diagnosing wear of the sliding interface based on a change in the amount of electricity related to the load of the drive device when the moving portion comes into contact with the corresponding contact portion;
Equipped with a,
The sliding direction of the upper slide relative to the lower slide is the Z-axis direction, the direction orthogonal to the Z-axis direction is the X-axis direction, and the Z-axis direction and the direction orthogonal to the X-axis direction are the Y-axis directions. As
The control device for the lower slide, the upper slide, by detecting the pitching yawing or the Y-axis direction of the X-axis direction, the wear diagnosis system that diagnoses the wear of the sliding interface. The driving device is a motor having an encoder,
The wear diagnosis system according to claim 1, wherein the contact portion is a stopper with which the upper slide contacts in order to determine an origin of the encoder. The controller is
An initial state storage step of storing, as initial data, a change in the amount of electricity when the moving portion is brought into contact with the contact portion in an initial state in which the lower slide and the upper slide are set; ,
In a state chronologically after the initial state, the change in the amount of electricity when the moving part is brought into contact with the corresponding contact part is compared with the initial data, and the wear of the sliding interface is compared. A diagnostic process to diagnose;
A notification step of notifying the operator of the diagnosis result in the diagnosis step;
The wear diagnostic system according to claim 1 or 2 which performs. A display device electrically connected to the control device and having a screen;
The wear diagnosis system according to claim 3, wherein in the notification step, the control device displays a matter related to the diagnosis result on the screen.   5. The wear diagnosis system according to claim 3, wherein the control device moves the moving unit stepwise with respect to the abutting unit via the driving device in the diagnosis step. The control device diagnoses wear of the sliding interface by detecting yawing in the X-axis direction of the upper slide with respect to the lower slide,
The razor is attached to one end of the upper slide in the X-axis direction,
The wear diagnosis system according to claim 1 , wherein the contact portion is attached to the other end in the X-axis direction of the lower slide .

Images