JP2020004288A - Positioning stage and processing machine with positioning stage - Google Patents

Abstract

To provide a processing machine that has improved positioning accuracy by hindering vibration of a positioning stage of counterweight system.SOLUTION: A positioning stage comprises: a first stage comprising a first motor and a first position detection sensor and movable in a vertical direction; a second stage comprising a second motor and a second position detection sensor and movable in a vertical direction; and a coupling member supported by a pulley and coupling the first stage and the second stage. In the first stage, the first motor is feedback controlled for the first stage on the basis of a detection value from the first position detection sensor, and a second motor is feedback controlled for the second stage on the basis of a differential value resulting from a difference between the detection value from the first position detection sensor and the detection value from the second position detection sensor.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a positioning stage having a counterweight type self-weight compensation mechanism. In particular, the present invention relates to a positioning stage that can be suitably used in a field of a processing machine or the like that performs processing using a tool in connection with a technique for suppressing stage vibration.

In the field of the positioning stage, an apparatus having a counterweight type self-weight compensation mechanism is known. Specifically, it is a mechanism in which the positioning stage and the counterweight are connected by a steel belt supported by a pulley, and the weight of the positioning stage is compensated by the counterweight.
In the counterweight method, a method is known in which a motor is installed on each of the positioning stage and the counterweight, and both the positioning stage and the counterweight are controlled in synchronization with a position command value of the positioning stage.

  For example, in the device described in Patent Literature 1, a linear motor and a position detection sensor are installed on a positioning stage, and a linear motor is installed on a counterweight. A method is described in which the rate of change of the actual current command of the positioning stage is multiplied by the weight ratio of the counterweight and the positioning stage to calculate the current value of the linear motor on the counterweight side.

  In the device described in Patent Document 2, a linear motor and a position detection sensor are installed on a positioning stage, and a motor is installed on a counterweight and a pulley. A control method is described in which an acceleration command calculated based on a position command value of a positioning stage is given to a pulley and a counterweight.

When such a counterweight type positioning stage is incorporated in a processing machine, a cover may be provided to protect mechanical components such as a motor and a position detection sensor from flying chips and processing liquid.
As a cover that can be used, for example, a cover mechanism described in Patent Literature 3 or Patent Literature 4 is known.

JP-A-2005-7517 JP 2000-352592 A JP 2010-242907 A JP 2006-167836 A

The device described in Patent Literature 1 or Patent Literature 2 is a control method for preventing a vibrational force from acting on a positioning stage in a system including a positioning stage, a counterweight, and a steel belt. is there.
However, the steel belt that connects the positioning stage and the counterweight interferes with each other's feedback system and exerts an oscillating effect. As a result, the control gain does not increase, and the positioning performance cannot be sufficiently exhibited. there were.

  Further, when the cover of Patent Document 3 or Patent Document 4 is laid on a processing machine having a positioning stage of a counterweight type, the cover bends and vibrates when the stage moves, and the drive mechanism of the stage and the counterweight and the cover are moved. Contact and sliding may occur. As a result, the positioning performance of the positioning stage may be affected. This effect becomes more remarkable when the weight balance changes due to the attachment of chips and processing fluid to the cover. Thus, there has been a problem that the positioning stage cannot sufficiently exhibit the positioning performance due to the influence of the cover.

  The present invention includes a first motor and a first position detection sensor, a first stage movable in a vertical direction, a second stage including a second motor and a second position detection sensor, a second stage movable in a vertical direction, A connection member supported by a pulley and connecting the first stage and the second stage, and a control unit, wherein the control unit is configured to control the detection value of the first position detection sensor for the first stage. Based on the feedback control of the first motor, for the second stage, based on the differential value of the difference between the detection value of the second position detection sensor and the detection value of the first position detection sensor, based on the differential value of the second motor A positioning stage for performing feedback control.

  Also, the present invention provides a first stage including a first motor and a first position detection sensor and movable vertically, and a second stage including a second motor and a second position detection sensor and movable vertically. And a connecting member supported by a pulley and connecting the first stage and the second stage, and a control unit, wherein the control unit is one of the first stage and the second stage. Can be controlled as a positioning stage, and the other can be controlled as a counterweight. For the stage controlled as the positioning stage, the motor of the stage is feedback-controlled based on a detection value of a position detection sensor of the stage, and the counter is controlled. For a stage to be controlled as a weight, control is performed as a value detected by a detection sensor of the stage and the positioning stage. Based on the differential value of the difference between the detected value of the position detection sensor stage, a feedback control of the stage motor, a positioning stage, wherein a.

  In addition, the present invention includes a first motor and a first position detection sensor, a first stage movable in a vertical direction, a second stage including a second motor, and a second stage movable in a vertical direction, supported by a pulley. A connection member for connecting the first stage and the second stage, and a control unit, the control unit, for the first stage, based on the detection value of the first position detection sensor, the second One motor is feedback controlled, and for the second stage, the position of the second stage calculated based on the detection value of the first position detection sensor and the command value to the first motor, and the first position detection sensor A feedback control of the second motor based on a differential value of a difference between the detected values.

  The present invention realizes a counterweight type positioning stage with high positioning accuracy. When the positioning stage of the present invention is used for a processing machine, the relative positioning accuracy between the tool and the workpiece is increased, and a processing machine with extremely high processing accuracy can be realized.

FIG. 2 is a block diagram of a control unit according to the first embodiment. (A) The front view of the processing machine of an embodiment. (B) A perspective view from the left. (C) A perspective view from the right. FIG. 2 is a block diagram illustrating a configuration of a control system according to the embodiment. (A) Relationship between Z command speed and Z control deviation when driven at a constant speed. (B) Transfer characteristics when driven at a constant speed. (C) Relationship between Z command speed and Z control deviation in the embodiment. (D) Transfer characteristics in the case of the driving method of the embodiment. (A) A specific configuration example of an embodiment including an offset current detection unit. (B) Transfer characteristics in the case of the driving method of the embodiment. (C) The figure which shows the relationship between the Z integration output band limitation part pass band of embodiment, and the W band limitation part pass band. The block diagram which shows the structure which can switch between Z-axis side processing and W-axis side processing. FIG. 4 is a control block diagram when processing is performed on a Z stage in the embodiment. FIG. 3 is a control block diagram when processing is performed on a W stage in the embodiment. FIG. 10 is a block diagram of a control unit according to the second embodiment. (A) Front view of a multi-task machine according to a third embodiment. (B) A rear view of the multifunction machine according to the third embodiment. (A) The figure which shows the positional relationship between a backing plate and a support member when a W stage is located near the center. (B) The figure which shows the positional relationship between a backing plate and a support member when a W stage moves down. (C) The figure which shows the positional relationship of a backing plate and a support member when a W stage moves up. (D) A horizontal sectional view taken along line AA.

[Embodiment 1]
Hereinafter, a positioning stage according to a first embodiment of the present invention and a processing machine having the positioning stage will be described with reference to the drawings.
2A, 2B, and 2C are a front view, a left perspective view, and a right perspective view of a processing machine including the positioning stage of the first embodiment, respectively. .

  In each of the figures, reference numeral 201 denotes a platen of a processing machine, 202a and 202b denote columns, and upper portions of the columns 202a and 202b are connected to each other by beams 203 to form a gate-shaped structure on the platen 201. . The platen 201, the column 202a, the column 202b, and the beam 203 can be made of, for example, a casting or a welding member. Reference numeral 204 denotes an anti-vibration table that does not transmit vibration from the floor to the processing machine.

On the surface plate 201, a Y stage 205 that can freely move along the Y direction is mounted. The Y stage 205 includes a motor (not shown) and a position detection sensor. As a stage guide for moving in the Y direction, for example, a rolling linear guide, a hydrostatic pressure bearing, or an aerostatic pressure bearing can be used. A bellows, a telescopic cover, or both, not shown, are laid to cover the Y stage 205 in order to prevent foreign matter such as cutting chips and processing liquid from entering.
On the Y stage 205, a C stage 207 capable of mounting and rotating an object to be processed is mounted. The C stage 207 includes a motor and a position detection encoder (not shown).

  The column 202a has a first stage mounted thereon a Z stage 208 that is freely movable in the Z direction (vertical direction) and can be positioned. The Z stage 208 includes a Z position detection sensor 210 that detects a position in the Z direction as a first position detection sensor, and a Z motor 209 as a first motor. As the stage guide, for example, a rolling linear guide, an oil static pressure bearing, or an air static pressure bearing can be used. A sheet-like cover (not shown) is provided to protect the Z stage 208 from foreign matter such as cutting chips and processing liquid.

  The Z stage 208 has an X stage 211 that is freely movable in the X direction, and includes a position detection sensor and a motor (not shown) for detecting a position in the X direction. As the stage guide for moving in the X direction, for example, a rolling linear guide, a hydrostatic bearing, or an aerostatic bearing can be used. A bellows cover (not shown) is laid to protect the X stage 211 in order to prevent foreign substances such as cutting chips and processing liquid from entering. Further, a first processing spindle 212 is mounted on the X stage 211, and it is possible to chuck a processing tool.

  On the column 202b, a W stage 213 that is freely movable and positionable in the Z direction (vertical direction) is mounted as a second stage. The W stage 213 includes a W position detection sensor 215 that detects a position in the Z direction as a second position detection sensor, and a W motor 214 as a second motor. As the stage guide, for example, a rolling linear guide, an oil static pressure bearing, or an air static pressure bearing can be used. A sheet-like cover (not shown) is laid to protect the W stage 213 from intrusion of foreign matter such as cutting chips and machining fluid.

  The W stage 213 is equipped with a U stage 216 that is freely movable in the X direction. The stage includes a position detection sensor (not shown) for detecting a position in the X direction and a motor. As the stage guide for moving in the X direction, for example, a rolling linear guide, a hydrostatic bearing, or an aerostatic bearing can be used. A bellows cover (not shown) is laid to protect the U stage 216 in order to prevent foreign substances such as cutting chips and processing liquid from entering. Further, a second processing spindle 217 is mounted on the U stage 216, and it is possible to chuck a processing tool.

  To balance the weight of the Z stage 208 and the W stage 213, a pulley 218 supporting a steel belt 219 is disposed on the beam 203, and the Z stage 208 and the W stage 213 are connected by a steel belt 219 as a connecting member. I have. It is desirable that the weights of the Z stage 208 and the W stage 213 be substantially equal.

The processing machine according to the present embodiment is a multifunctional processing machine capable of performing processing using either the first processing spindle or the second processing spindle. When processing is performed using the first processing spindle, the Z stage 208 functions as a positioning stage, and the W stage 213 functions as a counterweight. When processing is performed using the second processing spindle, the W stage 213 functions as a positioning stage, and the Z stage 208 functions as a counterweight.
In the following description, unless otherwise specified, it is assumed that processing is performed with the first processing spindle, that is, the case where the Z stage 208 functions as a positioning stage and the W stage 213 functions as a counterweight.

  FIG. 3 is a block diagram illustrating a configuration of a control system of the multi-task machine according to the present embodiment. The NC program 300 is a machining coordinate file in which the motion trajectories of the Z stage 208, the C stage 207, the X stage 211, the Y stage 205, and the U stage 216 are described in a G code format.

The trajectory calculation unit 301 reads the NC program 300 and calculates a Z position command value, a C position command value, an X position command value, a Y position command value, and a U position command value as target positions of each stage at each time.
The Z position command value, the C position command value, the X position command value, the Y position command value, and the U position command value calculated by the trajectory calculation unit 301 are the Z servo control unit 302, the C servo control unit 303, and the X servo control unit, respectively. 304, the Y servo control unit 305, and the U servo control unit 315.

  The Z servo control unit 302 controls the Z motor 209 so that the detection value of the Z position detection sensor 210 matches the position command value. The C servo control unit 303 controls the C motor 306 so that the detection value of the C position detection sensor 307 matches the C axis command position. Further, the X servo control unit 304 controls the X motor 308 such that the detection value of the X position detection sensor 309 matches the X position command value. Similarly, the Y servo control unit 305 and the U servo control unit 315 determine that the Y motor 310 and the U motor 310 have the same position so that the Y position detection sensor 311 and the U position detection sensor 317 match the Y position command value and the U position command value, respectively. The motor 316 is controlled. Thereafter, the difference between the Z position command value on the first machining spindle side and the current coordinate in the Z direction, that is, the detection value of the Z position detection sensor 210 is defined as a control deviation.

  The W servo controller 312 will be described in detail with reference to FIG. In the multitasking machine of the present embodiment, when machining is performed on the first machining spindle, the W stage 213 acting as a counterweight is actively controlled using the W motor 214 in conjunction with the operation of the Z stage 208. .

  With reference to the block diagram of the entire control unit shown in FIG. 1, a method of controlling the Z stage 208 as a positioning axis will be described first. The Z servo control unit 302 that controls the Z motor of the Z stage 208 based on the Z position command value includes a Z position control unit 101 to which the output value of the Z position detection sensor 210 is fed back, and a first derivative of the Z position detection sensor 210 It has a Z speed control unit 102 to which a value is fed back. By adopting a double loop configuration by these two control units, the thrust of the Z motor for following the Z position command value is calculated. Here, the Z position control unit 101 and the Z speed control unit 102 are proportional control and proportional integral control, respectively, and are generally known control methods. The Z servo controller 302 may have a position loop single loop configuration such as PID control. The calculation result of the Z speed control unit 102 is converted into a current value by the Z current amplifier 103, and a thrust is generated by the Z motor 209.

  Next, the W servo controller 312 for actively operating the W stage 213 as its own weight compensation axis will be described. The W servo controller 312 includes a feedback control block 104, a feedforward control block 105, and a weight difference thrust control block 106.

  First, the feedback control block 104 will be described. The relative position detection unit 107 calculates a difference value between the outputs of the Z position detection sensor 210 and the W position detection sensor 215. This is for detecting a change in the length of the steel belt 219 connecting the Z stage 208 and the W stage 213. Next, a time change is calculated by differentiating the difference value, a control gain is multiplied by the W proportional control unit 108, a value whose sign is inverted is calculated, and the calculated value is input to the W band limiting unit 109. The W band limiting unit 109 performs a filtering process to pass only a component near the natural vibration frequency of the system constituted by the W stage 213 and the steel belt 219, and outputs the component to the W current amplifier 110. The feedback control block 104 acts to suppress disturbance due to floor vibration and natural vibration generated when the Z stage 208 is accelerated or decelerated.

Next, the feedforward control block 105 will be described. The feedforward control block 105 receives the Z position command value calculated by the trajectory calculation unit 301. Command acceleration calculation section 111 calculates a second order differential value based on the Z position command value, and inputs the calculation result to acceleration-thrust conversion section 112. The acceleration-thrust conversion unit 112 multiplies the second-order differential value by the mass of the Z stage 208 and outputs the multiplied value to the Z current amplifier 103 as a thrust addition value of the Z stage 208. Further, the acceleration-thrust converting unit 112 multiplies the second-order differential value by the mass of the W stage 213 and outputs the multiplied value to the W current amplifier 110 as a thrust added value of the W stage 213.
The feedforward control block 105 simultaneously applies a thrust corresponding to the same acceleration to the Z stage 208 and the W stage 213 when the Z position command value suddenly changes due to a rapid traverse operation or the like. Thereby, the steel belt 219 can be prevented from expanding and contracting due to the command value that changes rapidly.

  Next, the weight difference thrust control block 106 will be described. The offset current detection unit 113 performs a low-pass filter calculation process of extracting only a relatively slow variation component, that is, a low-frequency component, of the thrust command value of the Z servo control unit 302, and outputs the calculation result to W It is added to the input signal of the current amplifier 110. The weight difference thrust control block 106 compensates for the weight difference between the Z stage 208 and the W stage 213 and causes both the Z motor 209 and the W motor 214 to bear the thrust necessary to maintain a constant position. .

  FIG. 5A shows a specific configuration example of the offset current detection unit. The Z speed control unit 102 is configured by generally known PID control, that is, a P control unit 501, an I control unit 502, and a D control unit 503. The output of the I control unit 502 of the Z speed control unit 102 is extracted and input to the offset current detection unit 113, and the Z integration output band limiting unit 506 performs a filtering process for passing only low frequency components.

  With reference to FIGS. 5B and 5C, a method of determining a band to be passed in the filtering process will be described. As described above, W band limiting section 109 has a filter characteristic of passing only components near the natural vibration frequency of the system constituted by W stage 213 and steel belt 219. It is not preferable that the pass band of the W band limiting section 109 and the pass band of the Z integral output band limiting section 506 overlap each other when they are added and input to the W current amplifier 110. Therefore, as shown in FIG. 5C, the filter characteristics 504 of the Z-integral output band limiting unit 506 are set to be lower than the filter characteristics 505 of the W band limiting unit 109 to suppress the band overlap. ing.

Next, the operation of the control method according to the present embodiment will be described.
For comparison, first, FIG. 4A schematically shows the relationship between the Z command speed and the Z control deviation when the Z stage 208 is driven at a constant speed without controlling the W stage 213. The Z control deviation becomes oscillating during acceleration and gradually attenuates in the constant velocity region. This is because the W stage 213 vibrates and acts as a disturbance force on the Z stage 208 as a result of the steel belt 219 acting as an elastic body during acceleration of the Z stage. As described above, while the W stage 213 has a function of compensating the own weight of the Z stage 208 as a counterweight, it has a disadvantage that machining accuracy is affected by giving an oscillating disturbance to the Z stage.

  On the other hand, FIG. 4C illustrates the Z control deviation reduced by the feedback control block 104 and the feedforward control block 105 of the present embodiment. As is apparent from comparison with FIG. 4A in which the W stage is not controlled, the vibration component inherent to the self-weight compensation of the control deviation generated due to the acceleration of the stage can be reduced.

  FIGS. 4B and 4D show the case where the thrust of the Z motor 209 is input and the value of the Z position detection sensor 210 is output for each of FIGS. 4A and 4C. It shows the transfer characteristics. As shown in FIG. 4B, if the W stage is not controlled, a vibration component unique to self-weight compensation occurs. However, in the present embodiment, as shown in FIG. 4D, the magnitude of vibration can be reduced by the two control blocks for controlling the W stage.

Further, in the present embodiment, the offset current that changes due to the mass of the second machining spindle 217 is reduced by the operation of the weight difference thrust control block 106 without impeding the vibration reduction effect of the W servo controller, and Heat generation can be suppressed. Further, compared with the case where the weight difference thrust control block 106 is not provided, motors having smaller rated outputs can be used for the Z motor 209 and the W motor 214, and the cost of the multi-tasking machine can be reduced.
As described above, when processing is performed on the first processing spindle using the Z stage as the positioning stage and the W stage as the counterweight, the processing machine according to the present embodiment can move the first processing spindle with extremely high accuracy in a short time. , So that advanced processing can be realized with high efficiency.

  The role of the Z stage may be fixed as a positioning stage and the W stage may be fixed as a counterweight. However, the multifunction machine according to the present embodiment uses the W stage as a positioning stage and the Z stage as a counterweight, and uses a second processing spindle. Processing is also possible. If different types of processing tools can be mounted on the first processing spindle and the second processing spindle and the roles of the positioning stage and the counter weight are switched and operated, different processing operations can be performed with high precision with one processing machine. It can be performed efficiently.

  FIG. 6 is a block diagram schematically showing a configuration capable of switching between a Z-axis side processing 313 for performing the processing operation on the Z stage and a W-axis side processing 314 for performing the processing on the W stage. The NC program 300 includes the operation trajectories of the X stage 211, the Y stage 205, the Z stage 208, the U stage 216, the W stage 213, and the C stage 207 in the work performed by each of the first machining spindle and the second machining spindle. Are described in the G code format. The control switching unit 318 analyzes which of the first machining spindle and the second machining spindle performs the machining operation based on the input NC program 300. Then, in the former case, the Z-axis machining 313 is activated, and in the latter case, the W-axis machining 314 is activated.

  The trajectory calculation unit 301 reads the NC program 300, and at the time of Z-axis machining, at each time, the Z position command value for the Z servo control unit 302, the X position command value for the X servo control unit 304, and the C position for the C servo control unit 303. Calculate the C position command value. At the time of processing on the W-axis side, a W position command value for the W servo control unit 312, a U position command value for the U servo control unit 315, and a C position command value for the C servo control unit 303 at each time are calculated.

  When processing is performed with the first processing spindle, position control is performed on the Z stage in the Z direction, and speed control or position control is performed on the W stage. When processing is performed by the second processing spindle, position control is performed on the W stage in the Z direction, and speed control or position control is performed on the Z stage.

  When switching the machining operation from the first machining spindle to the second machining spindle, the Z stage is kept in the servo lock state while the position control is being performed, and the W stage is switched from the speed control to the position control. After the both axes are in the position control state, the Z stage is switched to the speed control with the servo locked, so that the servo free state does not occur. When switching from the second machining spindle to the first machining spindle, the same processing may be performed by reading the Z stage and the W stage.

  FIG. 7 is a block diagram when processing is performed on the first processing spindle, that is, the Z stage, and the W stage is controlled to suppress a component that vibrates at a characteristic value determined by the weight of the counterweight and the spring property of the steel belt. FIG. The current coordinates of the Z axis are fed back from the Z position detection sensor 210 to the Z servo controller 302, and a thrust command is issued from the Z servo controller 302 to the Z motor 209. As for the W axis, the current coordinates of the W axis are acquired from the W position detection sensor 215. Further, the current coordinates of the Z axis are acquired from the Z position detection sensor 210. Then, the W servo controller 312 issues a thrust command to the W motor 214 so as to remove the vibration component using the respective coordinate data.

  FIG. 8 is a block diagram when processing is performed on the second processing spindle, that is, the W stage, and the Z stage is controlled so as to suppress a component that vibrates at an eigenvalue determined by the weight of the counterweight and the spring property of the steel belt. FIG. The current coordinates of the W axis are fed back from the W position detection sensor 215 to the W servo controller 312, and a thrust command is issued from the W servo controller 312 to the W motor 214. As for the Z axis, the current coordinates of the Z axis are acquired from the Z position detection sensor 210. Further, the current W-axis position is acquired from the W-position detection sensor 215. Then, a thrust command is issued from the Z servo controller 302 to the Z motor 209 so as to remove the vibration component using the respective coordinate data.

  As described above, in the multi-tasking machine according to the present embodiment, one stage is a positioning stage and the other stage is a counterweight, but it is possible to perform a machining operation by switching the role of the stage. When machining with any of the machining spindles, the magnitude of vibration generated at the time of positioning can be suppressed.

  Further, in the multi-tasking machine according to the present embodiment, by the action of the self-weight difference thrust control block, the offset current that changes due to the mass of the machining spindle can be reduced without inhibiting the vibration reduction effect of the servo control unit on the counterweight side. In addition, heat generation of the motor can be suppressed. Also, compared with the case where the weight difference thrust control block is not provided, motors with smaller rated outputs can be used for the Z motor and the W motor, and the cost of the multi-tasking machine can be reduced.

[Embodiment 2]
In the first embodiment, the position detection sensors for detecting the position in the Z direction are arranged on both the Z stage and the W stage. However, the second embodiment is different in that the position detection sensors are arranged only on the Z stage. In the present embodiment, the position of the W stage in the Z direction is not calculated based on the measurement value of the position detection sensor of the Z stage, but is obtained by calculation based on the measurement value of the position detection sensor of the Z stage.
FIG. 9 is a schematic block diagram for actively controlling the W stage acting as a counterweight in conjunction with the operation of the Z stage in the second embodiment.
The same parts as those in the first embodiment are denoted by the same reference numerals as those in FIG. 1, and the description is omitted here.

The control block configuration of the present embodiment shown in FIG. 9 is different from the first embodiment in that the W position detection sensor 215 in FIG. The W position estimation calculation unit 900 is a functional block that calculates the estimated position of the W stage and sends the result to the relative position detection unit 107.
The W-position estimation calculation section 900, the motor thrust _{F 1} from the Z motor 209 of the Z stage is, coordinate _{Z z} of the current Z-direction of the Z stage in the Z position detecting sensor 210 is input.

Here, the formula parameters are determined as follows.
M ₁ : Mass of Z stage M ₂ : Mass of W stage F ₁ : Motor thrust of Z stage F ₂ : Motor thrust of W stage Z _z : Current Z coordinate of Z stage Z _w : Current Z coordinate of W stage T: tension of the steel belt k: spring constant of the steel belt g: gravitational acceleration Then, the following three equations hold.

Further, if the resonance frequency of the stage is ω, the following equation is established.

The following equations are derived from Equations 1 to 4.

W position estimation calculation section 900, based on F ₁ and Z _z is entered, the current Z-direction of the coordinate Z _w of the W stage can be calculated using Equation 5 above. In the present embodiment, it is possible to calculate the current coordinates of the W stage without providing a position detection sensor on the W stage, and it is possible to reduce the cost of the multi-tasking machine as compared with the first embodiment.
In the multifunction machine according to the present embodiment, the magnitude of vibration generated at the time of positioning when machining with the first machining spindle can be reduced.

  In the multi-tasking machine of the present embodiment, the offset current, which varies with the mass of the machining spindle, is reduced by the action of the weight difference thrust control block without impairing the vibration reduction effect of the servo control unit on the counterweight side. However, heat generation of the motor can be suppressed. Also, compared with the case where the weight difference thrust control block is not provided, motors with smaller rated outputs can be used for the Z motor and the W motor, and the cost of the multi-tasking machine can be reduced.

[Embodiment 3]
The multifunction machine according to the third embodiment includes a sheet-like cover that can be wound up in a roll shape to protect the positioning stage from flying chips and machining fluid.
FIG. 10A is a front view of the multi-tasking machine according to the third embodiment, and FIG. 10B is a rear view.
In the drawing, reference numeral 1001 denotes an installation frame of a Z stage cover attached to the Z stage 208, and reference numeral 1002 denotes an installation frame of a W stage cover attached to the W stage 213. Reference numeral 1003 denotes a sheet-like cover for sealing an opening formed between the positioning stage and the stage base. A total of four covers are provided above and below the Z stage and above and below the W stage. Reference numeral 1004 denotes a winding machine that winds a sheet-shaped cover in a roll shape. Four winding units are installed in association with each cover, and springs (not shown) are provided so that the covers that move up and down as the stage moves do not loosen. The mechanism winds the cover.

  Reference numeral 1005 denotes a scraper for removing dust adhering to the sheet-like cover, and reference numeral 1006 denotes a scraper backing plate. The scraper and the backing plate of the scraper are fixed to the stage base by a support structure (not shown), and are brought into contact with each other in such a manner that a sheet-like cover is sandwiched therebetween, thereby removing dusts and the like adhering to the cover.

Reference numeral 1007 denotes a support member that prevents the sheet-shaped cover from being caught in the mechanical unit, and is installed above and below the Z stage cover installation frame and above and below the W stage cover installation frame at positions close to the cover. The shape of the support member may be a rod shape or a plate shape. An opening is provided in the contact plate of the scraper, so that interference with the support member can be avoided.
FIGS. 11A to 11C are schematic views showing a mechanism for preventing the scraper abutment plate and the support member of the stage cover from interfering with each other when the W stage moves.

  FIG. 11A shows a positional relationship between the backing plate 1006 and the support member 1007 when the W stage is located near the center in the Z direction. FIG. 11D is a horizontal sectional view taken along line AA of FIG. 11A. The scraper 1005 and the scraper abutment plate 1006 are positioned above and below the W stage 213 and are fixed to the stage base by a support structure (not shown). Remove dust such as powder. The support member 1007 is installed above and below the W stage cover installation frame 1002, and prevents the cover 1003 from bending in the X direction and getting caught in the mechanical unit.

  Here, FIG. 11B shows the positional relationship between the contact plate 1006 of the scraper and the support member 1007 when the W stage moves downward. When the W stage moves downward, the position where the scraper lower plate 1006 and the support member 1007 interfere with each other at the lower side of the W stage is set, but the interference is avoided by the opening provided on the lower plate. This makes it possible to prevent the cover from being caught in the mechanical part by the support member while removing dust attached to the cover by sandwiching the cover between the scraper and the contact plate of the scraper.

  In addition, FIG. 11C shows the positional relationship between the scraper abutment plate 1006 and the support member 1007 when the W stage moves upward. Similarly, when the W stage moves upward, the position where the scraper abutment plate 1006 and the support member 1007 of the scraper above the W stage interfere with each other, but the interference is avoided by the opening provided in the abutment plate. You. This makes it possible to prevent the cover from being caught in the mechanical part by the support member while removing dust attached to the cover by sandwiching the cover between the scraper and the contact plate of the scraper.

  According to the present embodiment, it is possible to prevent the sheet-shaped cover from flexing and vibrating, or from contacting or sliding with the drive mechanism of the stage or the counterweight to affect the positioning performance. Like a processing machine, it is possible to provide a positioning stage capable of high-speed, high-precision positioning without impairing the positioning performance even when incorporated in an environment where chips and processing liquid are scattered.

[Other embodiments]
Embodiments of the present invention are not limited to Embodiments 1 to 3 described above, and can be appropriately changed or combined.

  101: Z position control unit / 102: Z speed control unit / 103: Z current amplifier / 104: feedback control block / 105: feed forward control block / 106: own weight difference thrust Control block / 107 ... Relative position detection unit / 108 ... W proportional control unit / 109 ... W band limiting unit / 110 ... W current amplifier / 111 ... Command acceleration calculation unit / 112 ...・ Acceleration-thrust converter / 113 ・ ・ ・ Offset current detector / 201 ・ ・ ・ Stable / 202a, 202b ・ ・ ・ Column / 203 ・ ・ ・ Beam / 204 ・ ・ ・ Vibration isolation table / 205 ・ ・ ・ Y Stage / 207 ... C stage / 208 ... Z stage / 209 ... Z motor / 210 ... Z position detection sensor / 211 ... X stage / 212 ... First machining spindle / 21 ... W stage / 214 ... W motor / 215 ... W position detection sensor / 216 ... U stage / 217 ... second machining spindle / 218 ... pulley / 219 ... steel Belt / 300 NC program / 301 Locus calculation unit / 302 Z servo control unit / 303 C servo control unit / 304 X servo control unit / 305 Y servo Control unit / 306 C motor / 307 C position detection sensor / 308 X motor / 309 X position detection sensor / 310 Y motor / 311 Y position detection sensor /312...W servo control unit / 313 ... Z axis side machining /314...W axis side machining / 315 ... U servo control unit / 316 ... U motor / 317 ... U position Detection sensor / 318 ... Control off Unit / 501 ... P control unit / 502 ... I control unit / 503 ... D control unit / 504 ... Filter characteristics of Z integration output band limiting unit / 505 ... Filter of W band limiting unit Characteristics / 506: Z-integral output band limiting unit / 900: W position estimation calculation unit / 1001: Z-stage cover installation frame / 1002: W stage cover installation frame / 1003: seat Cover / 1004 · · · Winding machine / 1005 · · · Scraper / 1006 · · · Plate for scraper / 1007 · · · Support member

Claims (17)

A first stage including a first motor and a first position detection sensor, and movable in a vertical direction,
A second stage including a second motor and a second position detection sensor, and movable in a vertical direction,
A connecting member that is supported by a pulley and connects the first stage and the second stage;
And a control unit,
The control unit includes:
For the first stage, based on the detection value of the first position detection sensor, feedback control of the first motor,
For the second stage, based on the differential value of the difference between the detection value of the second position detection sensor and the detection value of the first position detection sensor, to feedback control the second motor,
A positioning stage, characterized in that: The control unit includes:
A command acceleration is calculated by differentiating the target position of the first stage by the second order,
For the first stage, in addition to the feedback control, feed forward control the first motor based on the product of the weight of the first stage and the command acceleration,
In the second stage, in addition to the feedback control, to feed-forward control the second motor based on the product of the command acceleration and the weight of the second stage,
The positioning stage according to claim 1, wherein: The control unit includes:
The low frequency component is extracted from the signal for performing the feedback control of the first motor, and is added to the signal for performing the feedback control of the second motor,
The positioning stage according to claim 1 or 2, wherein: The control unit includes:
For the second stage, when performing feedback control of the second motor, perform a filtering process to pass a component near the natural vibration frequency of the system configured by the second stage and the connecting member,
The positioning stage according to claim 1, wherein: A positioning stage according to any one of claims 1 to 4,
A tool can be mounted on the first stage, and the second stage functions as a counterweight.
A processing machine characterized by the following. A first stage including a first motor and a first position detection sensor, and movable in a vertical direction,
A second stage including a second motor and a second position detection sensor, and movable in a vertical direction,
A connecting member that is supported by a pulley and connects the first stage and the second stage;
And a control unit,
The control unit includes:
One of the first stage and the second stage can be controlled as a positioning stage, and the other can be controlled as a counterweight,
For the stage to be controlled as the positioning stage, based on the detection value of the position detection sensor of the stage, feedback control of the motor of the stage,
For the stage controlled as the counterweight, the motor of the stage is feedback-controlled based on the differential value of the difference between the detection value of the detection sensor of the stage and the detection value of the position detection sensor of the stage controlled as the positioning stage. ,
A positioning stage, characterized in that: The control unit includes:
A command acceleration is calculated by differentiating the target position of the stage controlled as the positioning stage by the second order,
For the stage to be controlled as the positioning stage, in addition to the feedback control, feedforward control of the motor of the stage based on the product of the command acceleration and the weight of the stage to be controlled as the positioning stage,
For the stage to be controlled as the counterweight, in addition to the feedback control, to feedforward control the motor of the stage based on the product of the command acceleration and the weight of the stage to be controlled as the counterweight,
The positioning stage according to claim 6, wherein: The control unit includes:
A low-frequency component is extracted from a signal for performing feedback control on the stage motor to be controlled as the positioning stage, and added to a signal for performing feedback control on the stage motor to be controlled as the counterweight,
The positioning stage according to claim 6, wherein: The control unit includes:
For the stage to be controlled as the counterweight, when performing feedback control of the motor of the stage, perform a filtering process to pass a component near the natural vibration frequency of the system configured by the stage and the connecting member,
The positioning stage according to any one of claims 6 to 8, wherein: A positioning stage according to any one of claims 6 to 9,
A tool can be attached to the first stage and the second stage,
A processing machine characterized by the following. A first stage including a first motor and a first position detection sensor, and movable in a vertical direction,
A second stage including a second motor and movable in a vertical direction,
A connecting member that is supported by a pulley and connects the first stage and the second stage;
And a control unit,
The control unit includes:
For the first stage, based on the detection value of the first position detection sensor, feedback control of the first motor,
For the second stage, the differential of the difference between the position of the second stage and the detection value of the first position detection sensor calculated based on the detection value of the first position detection sensor and the command value to the first motor Based on the value, feedback control of the second motor,
A positioning stage, characterized in that: The control unit includes:
A command acceleration is calculated by differentiating the target position of the first stage by the second order,
For the first stage, in addition to the feedback control, feed forward control the first motor based on the product of the weight of the first stage and the command acceleration,
In the second stage, in addition to the feedback control, to feed-forward control the second motor based on the product of the command acceleration and the weight of the second stage,
The positioning stage according to claim 11, wherein: The control unit includes:
The low frequency component is extracted from the signal for performing the feedback control of the first motor, and is added to the signal for performing the feedback control of the second motor,
The positioning stage according to claim 11, wherein: The control unit includes:
For the second stage, when performing feedback control of the second motor, perform a filtering process to pass a component near the natural vibration frequency of the system configured by the second stage and the connecting member,
The positioning stage according to any one of claims 11 to 13, wherein: A positioning stage according to any one of claims 11 to 14,
A tool can be mounted on the first stage, and the second stage functions as a counterweight.
A processing machine characterized by the following. Each stage of the first stage and the second stage,
A sheet-like cover that can be moved along with the movement of the stage and can be wound into a roll,
A scraper arranged to abut on the cover and fixed to a base of each stage;
A caul plate arranged opposite to the scraper with the cover interposed therebetween and fixed to a base of each stage,
A support member arranged in proximity to the cover and fixed to each of the stages,
An opening is provided in the backing plate so that the support member does not interfere with the backing plate when each of the stages moves.
The processing machine according to any one of claims 5 to 10, characterized in that: The support member is a plate-shaped or rod-shaped member,
17. The processing machine according to claim 16, wherein:

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