JP5885105B2 - Automatic correction device and automatic correction method for machine tool - Google Patents

Description

  The present invention relates to an automatic correction device and an automatic correction method for a machine tool that perform energy-saving control of a drive source when cutting is stopped for a long time in a machine tool.

Conventionally, a workpiece is continuously cut by unattended operation in a machining center of a machine tool, for example. For example, when there is no work material at night or when there is no monitoring personnel, this is detected and the spindle for gripping the cutting tool is set to the origin position in the X-axis, Y-axis, and Z-axis directions or to a predetermined standby position. Move to keep the machine stationary for a long time.
At this time, the X-axis and Z-axis drive servomotors can be stopped. However, in the Y-axis direction, which is the vertical axis, it is necessary to maintain its own position against gravity in order to keep the main shaft at the origin position or the standby position, and current always flows through the Y-axis drive motor. Is held in the drive state. For this reason, the Y-axis drive motor generates heat, and the heat is transmitted to the machine tool main body, so that the accuracy of the machine tool is lowered and the machining accuracy of the workpiece is deteriorated.

As means for improving such problems, for example, inventions described in Patent Documents 1, 2, and 3 below are disclosed.
For example, in the invention described in Patent Document 1, it is determined whether or not the control device that controls the punch press machine is in automatic operation, and as hydraulic drive means for supplying pressure oil to the hydraulic cylinder when it is not in automatic operation. The drive of the press motor is stopped. As a result, noise reduction and energy savings by press motors can be achieved when not in automatic operation.
Further, in the servo mechanism control device described in Patent Document 2, the power supply to the servo motor provided in the movable part that moves the controlled object to the predetermined position is stopped at the time of stop, and the brake device of the movable part is operated. The movable part is stopped at a predetermined position. When power supply to the servo motor is stopped, the actual amount of movement in the movable part is detected and input by the position detection sensor, and an abnormal signal is output when the actual amount of movement of the movable part is outside the preset allowable range Like to do.

However, since the energy-saving device of the punch press machine described in Patent Document 1 performs the energy-saving control by stopping the power drive means when it is not in automatic operation, it is energy-saving when the raw material runs out in the case of unmanned operation or the like. There is a fault that cannot be controlled.
Further, in the servo mechanism control device described in Patent Document 2, when this is applied to a machine tool, when the movable part moves when power supply to the servo motor is stopped, the main shaft is held by the movement of the main shaft. There was a problem that the tool and the workpiece fixed to the table might interfere with each other.

  On the other hand, in the machine tool control apparatus disclosed in Patent Document 3, the origin is a reference point position within an effective range set in advance in the three axis directions of the X axis, the Y axis, and the Z axis when the machining is stopped. The main shaft is held at a position where it does not interfere with the workpiece in the X-axis or Z-axis direction. After the stop state has elapsed for a predetermined time, the energy saving mode is started to turn off the power to the Y-axis servo motor, X-axis servo motor, and Z-axis servo motor, and the amount of misalignment of the main shaft in the Y-axis direction is detected. The energy-saving mode is canceled when the amount of displacement is outside the effective range.

JP 2000-153318 A Japanese Patent Laid-Open No. 4-15807 JP 2009-245007 A

However, in the machine tool control device described in Patent Document 3, when the Y-axis servo motor is a type of motor that does not have an absolute position detection function, if the power supply to the Y-axis servo motor is turned off in the energy saving mode, A positional deviation in the Y-axis direction occurs due to the weight, and the coordinate position of the main axis becomes unclear.
Therefore, when exiting the energy-saving mode, it is necessary to first perform an operation to return the spindle to the origin position, and then set a new machining start point and move the spindle to position it. There is a drawback that operations such as setting a starting point are complicated and time-consuming.

  The present invention has been made in view of such circumstances, and cuts the power when the drive of the machine tool is stopped to perform energy saving control, and automatically corrects the position of the spindle when releasing the energy saving control. An object of the present invention is to provide an automatic correction device and an automatic correction method for a machine tool that can be performed.

An automatic correction device for a machine tool according to the present invention cuts a workpiece by relatively moving a spindle for gripping a tool in three axial directions of an X axis, a Y axis, and a Z axis perpendicular to the workpiece. A machine tool that performs energy saving control by cutting off the power supply to the drive source of the spindle in a standby state after cutting is completed, and a storage unit that stores the coordinate position of the spindle at the stage when the workpiece has been cut A reference point indicating means for moving the main shaft to a reference point within a preset effective range in the three axis directions of the X axis, the Y axis and the Z axis before shutting off the power of the driving source of each axis; Based on the emergency stop means for cutting off the power of the drive sources of each axis including at least the main axis, X axis, Y axis, and Z axis necessary for machining, and the coordinate position information of the main spindle stored in the storage means after the end of the standby state The main spindle is used to cut workpieces Characterized by comprising a moving means for returning to the coordinate position in the completion stages.
According to the present invention, after the machining of the workpiece is finished, the coordinate position of the spindle is stored in the storage means, and then the spindle is moved to the reference point based on the instruction of the reference point instruction means, and thereafter, The power consumption can be reduced by switching to the energy saving mode by shutting off the power of at least the drive source of each axis necessary for cutting by the emergency stop means, but the coordinate position information of the spindle disappears and the reference point The main shaft held at the position will be displaced in the Y-axis direction. Then, when power is supplied to the drive source of each axis after the energy saving mode is finished, the coordinate position information of the spindle after the cutting process previously stored in the storage means is read, and the spindle is then cut by the moving means the previous time. Since it is possible to return to the coordinate position after the completion of machining, the next workpiece cutting can be smoothly started after the next cutting is completed in the standby state in the energy saving mode.

Further, it is preferable that the moving means moves the main axis to the coordinate position of the main spindle at the stage when the workpiece has been cut with reference to the original coordinate after returning the main axis to the original coordinate position.
In the energy saving mode standby state, the power of the driving source of each axis necessary for cutting is cut off, so the coordinate position information of the main axis disappears and the position of the main axis cannot be recognized due to misalignment in the Y axis direction. By returning to the origin coordinate position, it is possible to move to the coordinate position of the spindle at the stage where the cutting of the workpiece stored in the storage means is completed with the origin coordinate position as a reference.

In the emergency stop means, all power sources other than the NC, servo system, and sequencer may be shut off.
As a result, it is possible to cut off the power of the drive source of each axis necessary for the cutting process including the main axis, the X axis, the Y axis, and the Z axis and the power of the peripheral device having relatively large power consumption. Significant power savings can be achieved.

Further, the machine tool does not have a function of detecting the absolute position of the spindle.
Even if the drive source of each axis required for cutting including the main axis, X axis, Y axis, and Z axis is a machine tool that does not have an absolute position detection function, the power of the equipment in the non-cutting standby state Can be cut off to save power.

The automatic correction method for a machine tool according to the present invention cuts a workpiece by relatively moving a spindle for gripping a tool in three axial directions of X, Y, and Z that are orthogonal to the workpiece. An automatic correction method for machine tools that performs energy-saving control by cutting off the power to the spindle drive source in the standby state after cutting is completed, and stores the coordinate position of the spindle at the stage when workpiece cutting is completed The main axis is X-axis, Y-axis, and Z-axis before cutting off the power of the drive source of each axis including at least the main axis, X-axis, Y-axis, and Z-axis necessary for cutting in the standby state A step of moving to a reference point within a preset effective range in the direction, a step of cutting off the power of the driving source of each axis necessary for at least cutting, and a stage in which the cutting of the workpiece is completed after the end of the standby state Coordinate position of the main axis at Characterized by comprising a step of moving the main shaft.
According to the present invention, after the machining of the workpiece is finished, the coordinate position of the spindle is memorized, and then the spindle is moved to the reference point and held, and then enters a standby state and is at least cut by the emergency stop means. Power consumption can be reduced by switching to the energy saving mode by shutting off the power of the drive source of each axis necessary for the main axis, but the coordinate position information of the main axis is lost, and the main axis held at the reference point position depends on its weight. This will cause misalignment in the direction, making it impossible to recognize the coordinate position of the spindle. Even in this case, the power is supplied to the drive source of each axis after the energy-saving mode is finished, and the coordinates of the spindle after the end of the previous cutting process are read by reading the coordinate position information of the spindle after the cutting process stored in advance. Can be returned to position. Therefore, the standby power in the energy saving mode can be cut, and even if the position information of the spindle is lost when the cutting process is resumed, the spindle can be reliably moved to the coordinate position after the end of the previous cutting process and the cutting process can be resumed.

Also, in the step of moving the spindle to the coordinate position of the spindle at the stage where the workpiece has been cut, after returning the spindle to the origin coordinate position, the spindle is moved to the coordinate position of the spindle at the stage where the workpiece has been cut. It is preferable.
When power is supplied again to the drive source of each axis required for cutting after the energy saving mode is finished, the spindle is moved to the origin coordinate position even if the coordinate position of the spindle is lost or misaligned due to power cut. Since the coordinate position can be recognized by returning, it can be moved to the coordinate position of the spindle at the stage where the cutting of the workpiece has been completed.

Further, when the energization to the drive source of the spindle is cut off, all the power supplies other than the NC, servo system, and sequencer power supplies may be cut off.
Thereby, in the standby state, the power of the machine tool can be largely cut to save power.

  Further, it is preferable that the machine tool does not have a function of detecting the absolute position of the spindle.

  According to the automatic correction device and the automatic correction method for a machine tool according to the present invention, even when the power is cut in the standby state and the spindle position information is lost or the spindle is displaced from the reference point, When the power cut ends, the position of the spindle is automatically corrected and moved to the coordinate position of the spindle at the end of the previous cutting, so that the cutting can be resumed. In addition, the standby power in the non-cutting state of the machine tool can be significantly cut off, so power saving can be achieved even for machine tools that lose the spindle position information due to power cuts. I can plan.

It is a perspective view which shows the principal part of the machine tool by embodiment of this invention. It is a principal part sectional side view of the machine tool shown in FIG. It is a block diagram of the automatic correction apparatus used for a machine tool. It is a 1st flowchart which shows the automatic correction method. It is a 2nd flowchart following a 1st flowchart. It is a figure which shows the effective range in an XY-axis coordinate, an origin, and the reference point position of a spindle.

Hereinafter, an automatic correction device for a machine tool and an automatic correction method thereof according to an embodiment of the present invention will be described with reference to FIGS.
The machine tool 1 shown in FIGS. 1 and 2 is of a type including a drive motor that does not have an absolute position detection function, for example. When the power is turned off, the drive motor loses its own position information. Can not.
The machine tool 1 according to the present embodiment is a machining center. A gate-shaped column 3 is erected at one end of a base 2, and a holding portion 4 is provided at a position facing the column 3 on the base 2. Here, in the machine tool 1, the vertical axis is the Y axis, the horizontal direction in the horizontal plane orthogonal to the Y axis is the X axis, and the vertical direction orthogonal to the X axis is the Z axis.

  In the column 3, a pair of X-axis guide rails 6a and 6b are arranged in parallel in a direction orthogonal to the Y-axis direction, and the saddle is movable in the left-right direction (X-axis direction) along the X-axis guide rails 6a and 6b. 7 is disposed. The saddle 7 is provided with a pair of Y-axis guide rails 8a and 8b in the Y-axis direction, and a spindle head 9 that can be moved up and down (Y-axis direction) along the Y-axis guide rails 8a and 8b. Is provided. A main shaft 10 that holds a tool (not shown) projects from the main shaft head 9 in the Z-axis direction.

A ball screw 12 is erected on the saddle 7 in parallel with the Y-axis guide rails 8a and 8b. A Y-axis servo motor My is connected to one end of the ball screw 12 as a Y-axis drive source. A brake device 13 is attached to the Y-axis servo motor My (see FIG. 3). The ball screw 12 is held in a screwed state with the saddle 7 so that the saddle 7 can be moved up and down integrally with the main shaft 10 by forward and reverse rotation driving of the Y-axis servomotor My.
The saddle 7 is provided with a ball screw 14 in parallel with the X-axis guide rails 6a and 6b, and an X-axis servo motor Mx is connected to one end of the ball screw 14 as an X-axis drive source. The ball screw 14 is held in a screwed state with the saddle 7, and the saddle 7 can be moved integrally with the main shaft 10 in the X-axis direction by forward and reverse rotation driving of the X-axis servomotor Mx.

  The holding table 4 is provided with a pair of Z-axis guide rails 16a and 16b in a direction orthogonal to the X-axis direction. An APC (auto pallet changer) 17 is attached to the base 2 via a holding table 4, and the two pallets 18 a and 18 a supported on the upper part of the table 18 by the pivotable APC 17 can be exchanged. The table 18 is supposed to be movable in the front-rear direction (Z-axis direction) along the Z-axis guide rails 16a and 16b. A workpiece (not shown), which is a workpiece, is fixed to the pallet 18a at the machining position, and is subjected to cutting with a tool held on the spindle 10.

The pallet 18a at the machining position is connected to a Z-axis servo motor Mz as a Z-axis drive source via a ball screw 19, and the table 18 is moved to the Z-axis guide rail by rotating the Z-axis servo motor Mz forward and backward. It can be moved back and forth in the Z-axis direction along 16a and 16b.
The X-axis servo motor Mx and the Z-axis servo motor Mz are not provided with a brake device because the shaft is not affected by gravity, but the brake devices 27 and 29 are attached as shown by a one-dot chain line in FIG. Also good.

  In FIG. 3, an automatic correction device 20 that performs energy-saving control of a drive source such as each motor in the machine tool 1 is provided. The automatic correction device 20 controls the ON / OFF of the Y-axis servo motor My, the X-axis servo motor Mx, the Z-axis servo motor Mz and the like together with the spindle motor and B-axis motor (not shown), thereby supporting the workpiece 18. Control means 22 is provided for controlling the cutting of the workpiece by drivingly controlling the spindle 10 that holds the tool.

Then, in the control means 22, when the non-machining state of each drive source such as the main shaft motor, the B-axis motor, the Y-axis servo motor My, the X-axis servo motor Mx, and the Z-axis servo motor Mz continues for a predetermined time, the processing standby state Therefore, to save energy, the power supply is stopped (OFF). The power stop state and power cut state of each drive source in the processing standby state are referred to as an energy saving mode.
Here, the power source to be stopped is the power source of various drive sources other than the control power source of NC, servo system, sequencer in the machine tool 1, and specifically, the main axis 10, X axis, Y axis, Z axis, B These are each servo motor of the shaft, peripheral device 24 and the like.
When the cutting of the workpiece is completed in the control means 22, the effective range L shown in FIG. 6 for energy saving control of the spindle 10 by the moving means 23 based on the signal that detects the timing when the driving of the machine tool 1 is stopped. The motors My, Mx, and Mz are driven to move to the reference point position S.

Here, the reference point position S shown in FIG. 6 is preferably the position of the origin O (origin coordinates) of the X axis, the Y axis, and the Z axis or the vicinity thereof, and is held by the main shaft 10 at least in the X axis direction. The position at which the tool is displaced from the work held on the table 18, that is, the position at which the spindle 10 or the tool does not interfere with the work even if the spindle 10 is lowered by gravity. Alternatively, in the Z-axis direction, the spindle 10 and the tool are set at positions where they do not interfere with the workpiece even when the spindle 10 descends due to gravity. The reference point position S may be a position shifted so that the tool held on the main shaft 10 does not interfere in at least one of the X-axis direction and the Z-axis direction.
The origin O in the Y-axis direction in the plane of the XY axis is the intersection of the X axis and the Y axis in the XY axis coordinate plane shown in FIG. On the column 3 of the machine tool 1 shown in FIG. 1, the origin O is set at a position close to the X-axis guide rail 6a of the Y-axis guide rails 8a and 8b, for example, a position about 1 mm below the X-axis guide rail 6a. .

For the reference point position S, an effective range L that can be maintained in the energy saving mode state is set. This effective range L is the Y-axis direction in which the Y-axis servomotor My is stopped and the power supply is stopped and the Y-axis servomotor My is stopped by the brake device 13 in the Y-axis direction. Since it is directly connected to the ball screw 12, it is within an allowable range for the drop (shift amount) in the Y-axis direction based on the weight of the spindle 10 and the tool, the braking force that deteriorates with time of the brake device 13, and the like.
Further, in the X-axis and Z-axis directions, the main shaft 10 is allowed to move in the X-axis and Z-axis directions in the stopped state (see FIG. 6). Moreover, the effective range L includes the origin O.

  The effective range L is empirically set based on the weight of the spindle 10 and the tool described above, the appropriate braking force of the brake device 13, and the like. When the Y-axis servo motor My is connected to the ball screw 12 via a gear, it also includes an appropriate backlash distance. In FIG. 6, the effective range L is shown in the XY axis coordinate plane. In the standby state, the spindle 10 is moved to a predetermined reference point position S within the effective range L, for example, the origin O, by the moving means 23 as shown in FIG.

Further, the control unit 22 measures the stop time of each motor of the machine tool 1 with the timer 24 based on the signal that detects the timing when the drive of the machine tool 1 is stopped. The timer 24 starts the energy-saving mode when a predetermined time t, for example, t = 0 to 30 minutes, has elapsed, and cuts off the power supply to the Y-axis servo motor My and operates the brake device 13. Let
However, if the energy saving mode is started at the predetermined time t = 0 minutes, the brake device 13 is applied to the Y-axis servo motor My and the power supply to each motor is cut off. This is not preferable because the start of driving is slightly delayed due to the start control of each motor. It is preferable to start the energy saving mode by setting at least the predetermined time t to a time when about several minutes or more have passed.

The timer 24 includes a Y-axis drive source stop means 21y that outputs a power supply stop signal to the Y-axis servo motor My and an operation signal of the brake device 13 after a predetermined time t has elapsed or at an appropriate stage, and power supply to the motors Mx and Mz. X-axis drive source stop means 21x and Z-axis drive source stop means 21z for individually outputting stop operation signals are provided. When the brake devices 27 and 29 are provided in the X-axis servo motor Mx and the Z-axis servo motor Mz, the operation signals of the brake devices 27 and 29 are output simultaneously.
Further, the Y-axis servo motor My is provided with a position monitoring means 25 for detecting the position of the main shaft 10 in the Y-axis direction. The Y-axis servo motor My always has the main shaft 10 regardless of whether the Y-axis servo motor My is stopped or driven. The position in the Y-axis direction is detected and fed back to the control means 22.
Similarly, the position monitoring means 28 is also installed in the X-axis servomotor Mx, and the position monitoring means 30 is also installed in the Z-axis servomotor Mz.

Further, the control means 22 is provided with a determination means 32, a release means 33, an emergency stop means 34, a coordinate position storage means 35, a reference point position instruction means 36, and further an automatic control confirmation means 38. Next, each of these means will be described in detail.
The discriminating means 32 discriminates whether or not the position of the main spindle 10 in the axis direction in the standby state detected by the position monitoring means 25, 28, 30 is within the effective range L. In this determination means 32, in the energy saving mode, the position monitoring means 25 is based on the position in the Y-axis direction when the spindle 10 is moved to the reference point position S and the position after the power supply to the Y-axis servomotor My is cut off. Each position of the main spindle 10 detected by the above is also compared and determined (see FIG. 5).

If the main shaft 10 located at the reference point position S is cut off from the power supply to the Y-axis servo motor My, even if braking is applied by the brake device 13, a deviation that lowers in the Y-axis direction due to the weight of the main shaft 10 or the tool occurs. The amount of deviation in the Y-axis direction from the reference point position S is D.
The canceling unit 33 cancels the energy saving mode or displays an abnormality when the amount of deviation D in the Y-axis direction is outside the effective range L as determined by the determining unit 32.

The emergency stop means 34 is a means for instructing to stop the power supply of the drive means (drive source) other than the control power supply of the NC, the servo system, and the sequencer in the machine tool 1, for example, in the energy saving mode. 10, X-axis, Y-axis, Z-axis, and B-axis servomotors, peripheral devices 24, and the like. Compared with the conventional technology described above, since most of the power supplies except the control power supply for the NC, servo system, and sequencer in the machine tool 1 are shut off, the energy saving effect due to the power cut is high.
The coordinate position storage means 35 detects the coordinate position of the spindle 10 immediately before the Y-axis servo motor My, the X-axis servo motor Mx, and the Z-axis servo motor Mz enter the standby state by the position monitoring means 25, 28, and 30. To remember. In other words, the coordinate position storage means 35 stores the coordinate position of the spindle 10 at the stage when the workpiece has been cut. Then, when the standby state is completed, the spindle 10 is moved to this coordinate position by supplying power to the power source of the driving means, and is used as the next machining start point of the workpiece.

Further, the reference point position indicating means 36 is based on a signal that detects the timing when the Y-axis servo motor My, the X-axis servo motor Mx, and the Z-axis servo motor Mz are turned off and the drive of the machine tool 1 is stopped. An instruction signal is output to move 10 to a reference point position S within the effective range L shown in FIG. 6 for energy saving control, and each servo motor My, Mx, Mz is driven by the moving means 23.
The automatic control confirmation means 38 discriminates between the automatic mode and the manual mode of the machine tool, and controls to perform the automatic correction of the spindle position according to the present embodiment only in the automatic mode.

Further, the abnormality display means 40 is a release means when the amount of deviation D in the Y-axis direction of the main shaft 10 deviates from the preset effective range L when the power supply to the Y-axis servomotor My is cut off and the brake device 13 is operated. An abnormality display is performed by an instruction signal from 33.
In addition, as shown in FIG. 3, various devices can be applied as the peripheral device 42 whose power is shut off in the energy saving mode. Examples of the devices that use particularly large power include, for example, a coolant device 43, a workpiece changing device 44, and a tool changing device. The present invention can be applied to the device 45, the hydraulic device 46, and a lubrication device.

The machine tool 1 including the automatic correction device 20 according to the present embodiment has the above-described configuration. Next, an automatic correction method for energy-saving control of the machine tool 1 is illustrated in a block diagram of the automatic correction device 20 shown in FIG. And it demonstrates based on the flowchart shown in FIGS.
First, when the cutting of the workpiece by the machine tool 1 is completed, the operations of the main shaft motor, the B axis motor, the X axis servo motor Mx, the Z axis servo motor Mz, and the Y axis servo motor My are stopped (step 101).
When the control means 22 detects that all motors (main shaft motor, B axis motor, X axis servo motor Mx, Z axis servo motor Mz, Y axis servo motor My, etc.) are stopped, the timer 24 measures the stop time. Is started (step 102). It is determined by the timer 24 whether or not the predetermined state t set in advance has been stopped for the spindle 10 (step 103). Note that the energy saving mode is not entered if any of the motors starts to drive before the predetermined time t elapses.

When the measurement time of the timer 24 elapses a predetermined time t, the energy saving mode, which is a standby state for cutting, is entered. That is, the energy saving mode refers to a process of saving energy by stopping (OFF) the power supply because, for example, when the workpiece is not processed for a predetermined time, the workpiece waits for replenishment during unattended operation.
Here, the power supply in the standby state to be stopped is a power supply for various drive means except a control power supply for the NC, servo system and sequencer, which is a basic control system power supply for driving the machine tool 1. Specifically, the power supply for each axis such as the main axis, X axis, Y axis, Z axis, and B axis necessary for machining, the power supply for the peripheral device 24, and the like.

In step 103, when the timer 24 detects that the predetermined time t has elapsed, the coordinate position information of the spindle 10 at the end of workpiece machining is detected by the position monitoring means 25, 28, 30 and the coordinate position storage of the control means 22 is performed. The information is stored in the means 35 (step 104). Thereafter, an energy saving mode for turning off standby power is started (step 105).
Here, in order to resume machining from the standby power cut state in the energy saving mode, the operation of returning the spindle 10 to the origin by manual operation such as button operation is referred to as manual mode. The spindle 10 is controlled to move so that the next machining can be resumed from the emergency stop state, which is referred to as an automatic mode.

Therefore, it is determined from the energy saving mode whether the starting operation for the next workpiece machining is the manual mode or the automatic mode (step 106), and the energy saving mode is not entered in the manual mode. This is because in the manual mode, it is assumed that the operator operates operations such as workpiece feed, workpiece fast feed, and return to origin by the manual pulse generator.
In the automatic mode, an instruction signal from the reference point indicating means 36 of the control means 22 is output to the moving means 23, and the spindle 10 is moved to the reference point position S, for example, the origin (0, 0, 0) ( Step 107).
Then, the determination means 32 confirms that the X axis, Y axis, and Z axis direction positions of the main axis 10 at the reference point position are within the effective range L (step 108). If the effective range L is deviated in any of the axial directions, it can be estimated that any device such as the brake device 13 and the position monitoring unit 25 is abnormal, and thus the energy saving mode is terminated by the release unit 33.

Then, after the spindle 10 is moved to a preset reference point position S within the effective range L, for example, at or near the origin O, the emergency stop means 34 controls the NC, servo system, and sequencer control power of the machine tool 1. The power sources of the various drive means other than the emergency stop are stopped (step 109).
As a result, the spindle motor, B-axis motor, X-axis servo motor Mx, Z-axis servo motor Mz, and Y-axis servo motor My are stopped (OFF), and the coolant device 43, workpiece change device 44, tool change device 45, hydraulic pressure The power source of the peripheral device 42 such as the device 46 and the lubricating device is stopped (OFF) (step 110).

Here, the X-axis, Y-axis, and Z-axis servomotors Mx, My, and Mz are stopped by the emergency stop, and the main shaft 10 is braked by the brake device 13 with respect to the Y-axis servomotor My. Regarding the X-axis servo motor Mx and the Z-axis servo motor Mz, since the X-axis direction and the Z-axis direction are horizontal surfaces, the brake devices 27 and 29 may not be provided in each servo motor Mx and Mz. If so, braking is performed by the brake devices 27 and 29.
Then, in a state in which the main shaft 10 is moved to the reference point position S in step 107, the position monitoring means 25 detects in advance the coordinate value in the Y-axis direction of the main shaft 10 (referred to as the first coordinate value) by the Y-axis servo motor My. And remember. Then, the position monitoring means 25 detects and stores the coordinate value in the Y-axis direction of the spindle 10 (referred to as the second coordinate value) after the power supply of the Y-axis servomotor My is stopped due to an emergency stop in step 109.

Next, the control means 22 calculates the difference between the first coordinate value and the second coordinate value as a deviation amount D in the Y-axis direction of the spindle 10 (step 111), and the deviation amount D is set in a permissible range (effective range). L) It is discriminated by the discriminating means 32 whether it is within (step 112). When the deviation amount D exceeds the allowable range as the normal deviation amount by the brake device 13, it is determined that the brake device 13 is abnormal, and the abnormality display means 40 displays an abnormality (step 113).
If the second coordinate value of the position of the main shaft 10 is within the effective range L even if the amount of misalignment in the Y-axis direction is added, the brake device 13 does not deteriorate and the lowering of the main shaft 10 and the tool due to its weight is suppressed. Authenticated and normal.

In step 112, when the deviation amount D of the spindle 10 is out of the effective range L, an abnormality is displayed.
In this case, it may be determined that the deterioration of the brake device 13 has progressed or the Y-axis direction descent with time has progressed due to the weight of the spindle 10 and the tool, and the energy saving mode of the Y-axis servomotor My may be terminated. And you may stop the machine tool 1 and perform the maintenance of the brake device 13 of the Y-axis servomotor My. Alternatively, the maintenance operation may be performed at the time when the standby power is restored by canceling the emergency stop by continuing the energy saving mode only by warning with the abnormality display.

  In the energy saving mode, when the amount of deviation from the reference point position S of the main shaft 10 when the power supply to the Y-axis servo motor My is stopped is large, the main shaft 10 may interfere with the work in relation to the work installation position. However, in this embodiment, since the reference point position S of the main shaft 10, that is, the origin O is set to be shifted in at least one direction of the X axis direction and the Z axis direction with respect to the workpiece, the main shaft 10 is set in the Y axis direction, that is, the vertical direction. It does not interfere with the workpiece even when descending.

Next, when the work for attaching the workpiece for the next machining is completed on the pallets 18a, 18a and the next machining setup process is completed (step 114), for example, the workpiece on the pallets 18a, 18a is detected by a sensor (not shown). Alternatively, it is detected by another sensor that the setup for the next workpiece cutting process has been completed, the standby state, that is, the energy saving mode is terminated, the emergency stop of the power supply is released, and the power is restored (step 115).
Accordingly, the spindle motor, the B-axis motor, the X-axis servo motor Mx, the Z-axis servo motor Mz and the Y-axis servo motor My, which are power supplies for driving means other than the control power supply for the NC, servo system, and sequencer, and the coolant device 43 are also provided. Then, the power source of the peripheral devices 42 such as the work changer 44, the tool changer 45, the hydraulic device 46, and the lubricating device is turned on (ON).

  With these power connections, the automatic origin return program for the spindle 10 is started, the X-axis servo motor Mx, the Z-axis servo motor Mz and the Y-axis servo motor My of the spindle 10 are started, and the spindle 10 first returns to the origin O. (Step 117). Next, the control means 22 reads the coordinate position of the main spindle 10 at the end of the previous workpiece cutting process stored in the coordinate position storage means 35 before starting the energy saving mode in step 104, and the coordinate position is based on the origin O. Then, the spindle 10 is moved by the moving means 23 and positioned (step 118).

Since the machine tool 1 according to the present embodiment is a type of machine tool equipped with a drive motor that does not have an absolute position detection function, the power is turned off in the energy saving mode after the previous cutting process is completed, so that All the coordinate position information of the spindle 10 in the standby state is lost.
However, according to the automatic correction device 20 according to the present embodiment, the coordinate position of the spindle 10 at the end of the previous workpiece machining is read after the next workpiece machining setup after the next workpiece is placed on the pallets 18a and 18a. Since it can be re-recognized and positioned again, the next workpiece cutting can be started smoothly.

As described above, according to the automatic correcting device 20 for the spindle 10 in the machine tool 1 according to the present embodiment, all the power supplies except for the control power supply for starting the energy saving mode are shut off, and the spindle 10 has its weight and tool. Even if the position shift occurs due to the weight of the spindle or the coordinate position data of the main spindle 10 is lost, the coordinate position of the main spindle 10 after the end of the previous machining before the transition to the energy saving mode is automatically and smoothly after the end of the energy saving mode. It can be controlled to return to.
Moreover, even if the machine tool 1 does not have an absolute position detection function by automatically correcting the position of the spindle 10 when the standby state is released, significant power saving can be achieved by shutting off the power in the standby state of the energy saving mode. Electricity can be achieved.

  Further, the amount of deviation D in the Y-axis direction is calculated based on the first coordinate value of the main shaft at the start of the energy saving mode and the second coordinate value of the main shaft 10 when the power supply of the Y-axis servo motor My is stopped and the brake device 13 is braked. Thus, the degree of deterioration of the brake device 13 or the like can be detected. When a gear is interposed between the Y-axis servo motor My and the ball screw 12, an abnormality due to gear backlash can be detected.

As mentioned above, although preferable embodiment of this invention was described, this invention is not limited to the said embodiment. Additions, omissions, substitutions, and other modifications can be made without departing from the spirit of the present invention.
For example, the amount of deviation D may be detected by the position monitoring means 25, 28, 30 immediately after the timer 24 is omitted and the spindle 10 is positioned at the reference point position S. In this case, in the energy saving mode control stage, the main shaft 10 does not move in the X-axis direction and the Z-axis direction, which are two axes in the horizontal plane, and does not move, so the Y-axis direction (vertical axis direction) of the Y-axis servomotor My. Only the amount of descent to) may be detected.

  In the above-described embodiment, the power source for cutting power in the standby state of the machine tool 1 is a power source for driving means other than the control power source for the NC, servo system, and sequencer. For example, a spindle motor, a B-axis motor, and an X-axis servo Each axis necessary for cutting such as the motor Mx, Z-axis servo motor Mz, and Y-axis servo motor My, and further peripheral devices 42 such as a coolant device 43, a workpiece change device 44, a tool change device 45, a hydraulic device 46, a lubrication device, and the like. However, the present invention is not limited to the contents of the above-described embodiment, and other drives may be used as long as each axis includes at least the Y-axis, X-axis, Z-axis, and the like necessary for cutting. Any appropriate means can be selected. However, in order to increase the power saving in the standby state after the cutting process is completed, it is preferable to increase the power source of the driving unit that cuts the standby power as much as possible.

1 Machine tool
10 Spindle
18, 18a, 18b Table 13, 27, 29 Brake device,
20 Automatic correction device 21y Y-axis drive source stopping means 22 Control means 23 Moving means 24 Timers 25, 28, 30 Position monitoring means 34 Emergency stop means 35 Coordinate position storage means 36 Reference point indicating means 40 Abnormal display means 42 Peripheral device My Y Axis servo motor Mx X-axis servo motor Mz Z-axis servo motor L Effective range S Spindle reference point O Origin

Claims (8)

The workpiece is cut by moving the spindle holding the tool relative to the X axis, the Y axis, and the Z axis that are orthogonal to the workpiece, and enters the standby state after the workpiece has been cut. A machine tool that controls energy saving by shutting off power to the drive source of the spindle,
Storage means for storing the coordinate position of the spindle at the stage when the workpiece has been cut;
Reference point indicating means for moving the main shaft to a reference point within a preset effective range in the three axis directions of the X axis, the Y axis, and the Z axis before cutting off the power of the driving source of each axis;
Emergency stop means for cutting off the power of the driving source of each axis including at least the main axis, the X axis, the Y axis, and the Z axis necessary for cutting in the standby state;
A machine tool comprising: moving means for returning the spindle to the coordinate position at the stage when the workpiece has been cut based on the coordinate position information of the spindle stored in the storage means after completion of the standby state. Automatic correction device.   2. The machine tool according to claim 1, wherein the moving unit moves the spindle to a coordinate position of the spindle at a stage where the workpiece has been cut with reference to the origin coordinate after returning the spindle to the origin coordinate position. Machine automatic correction device.   The automatic correction device for a machine tool according to claim 1 or 2, wherein the emergency stop means shuts off all power sources other than the power source of the NC, servo system and sequencer.   The automatic correction device for a machine tool according to any one of claims 1 to 3, wherein the machine tool does not have a function of detecting an absolute position of a spindle. The workpiece is cut by moving the spindle holding the tool relative to the X axis, the Y axis, and the Z axis that are orthogonal to the workpiece, and in a standby state after the workpiece has been cut. An automatic correction method for machine tools that performs energy saving control by cutting off the power to the drive source of the spindle,
Storing the coordinate position of the spindle at the stage where the workpiece has been cut;
In the standby state, before cutting off the power of the drive source of each axis including at least the main axis, the X axis, the Y axis, and the Z axis necessary for cutting, the main axis is moved in the three axis directions of the X axis, the Y axis, and the Z axis. Moving to a reference point within a preset effective range;
Cutting off the power of at least the drive source of each axis necessary for the cutting process;
And a step of moving the spindle to the coordinate position of the spindle at the stage when the cutting of the workpiece is finished after the standby state is finished.   In the step of moving the spindle to the coordinate position of the spindle at the stage when the workpiece has been cut, the coordinates of the spindle at the stage where the workpiece has been cut after returning the spindle to the origin coordinate position The automatic correction method for a machine tool according to claim 5, wherein the method is moved to a position.   The automatic correction method for a machine tool according to claim 5 or 6, wherein when the energization to the drive source of the spindle is cut off, all power sources other than the NC, servo system and sequencer are cut off.   The automatic correction method for a machine tool according to any one of claims 5 to 7, wherein the machine tool does not have a function of detecting an absolute position of a spindle.

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