JP2011167787A - Device and method for measuring workpiece in machine tool - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a workpiece measurement device capable of performing three-dimensional measurement with high accuracy by minimum necessary measurement data without modifying a NC device. <P>SOLUTION: In the workpiece measurement device 20, a programmable controller 25 obtains position data of a measurement head 8. At the timing of the obtaining action, a pulse output part 24 outputs a timing pulse P. The measurement head measures the workpiece 9 by measurement instruction f output by positively quickening it than the timing of constant time interval by the previously set time difference by a forecasting system 29. As a result, the first time when the programmable controller obtains the position data C1 of the measurement head is made coincident with the second time when the measurement head measures the workpiece by the measurement instruction. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a workpiece measuring apparatus in a machine tool and a method thereof for measuring a workpiece with a wired measuring head attached to a moving body that moves relative to the workpiece within a machining area of the machine tool. .

In a machine tool such as a machining center, a technique has already been proposed for measuring the shape of the surface of a workpiece while the machined workpiece is installed on the machine tool without being removed from the machine tool. For example, Patent Document 1 (Japanese Patent Publication No. 2007-518579) describes a workpiece inspection system for machine tools.
In this inspection system, a probe (corresponding to the measuring head of the present invention) is mounted on the spindle of a machine tool. Measurement data when the probe needle is brought into contact with the workpiece (workpiece) is output, and the NC device also acquires probe position data. Then, the workpiece is inspected by combining the measurement data and the position data.

Special table 2007-518579 gazette

In the inspection system described in Patent Document 1, it has been necessary to modify or change the NC device such as adding a new function. In addition, an enormous number of measurement data is output from the probe as compared with the number of position data acquired by the NC apparatus. A necessary number of measurement data is selected from the enormous number of measurement data. As a result, a time lag occurs between the position data and the measurement data, and it is difficult to obtain a highly accurate result.
Moreover, since the number of measurement data is enormous, the amount of data increases overall. As a result, an interface for transmission and a CPU for arithmetic processing have to have a large processing capacity. It was also necessary to increase the memory capacity for storing a huge number of measurement data.
This system is a method in which the probe needle makes contact with the workpiece to perform measurement. Therefore, it is difficult to scan the probe at high speed safely and without vibration (or low vibration). Moreover, it was difficult to measure a wide range of the workpiece in a short time.

  The present invention has been made to solve such a problem, and the measuring head for the measurement point on the workpiece is not modified or modified without adding a new function to the NC device. The operation of acquiring data of at least two axial positions and the operation of measuring the workpiece by the measuring head at that time are always repeated at regular intervals at the same timing, and the minimum necessary measurement is performed. By processing the data, the workpiece can be measured two-dimensionally or three-dimensionally with high accuracy, and the measuring head scans at high speed and measures the workpiece with high accuracy in a short time. It is an object of the present invention to provide a workpiece measuring apparatus and method for a machine tool that can quickly shift to a machining operation after measurement.

In order to achieve the above-described object, a workpiece measuring device in a machine tool according to the present invention includes an NC device that controls the machine tool, and a moving body that moves relative to the workpiece within a machining area of the machine tool. A wire-type measuring head mounted on the workpiece for measuring the workpiece, a control device for controlling the workpiece measuring device, a first axial direction of the measuring head with respect to a point to be measured on the workpiece, and this measurement A programmable controller that acquires data of at least two axial positions including a second axial direction scanned by the head from the NC device at regular time intervals, and a pulse interval corresponding to the constant time intervals. The timing pulse is connected to a pulse output unit that outputs to the measurement head, and the wiring that electrically connects the pulse output unit and the measurement head, or the Or a prediction system provided in the programmable controller, the programmable controller acquires the position data of the measurement head, and at the timing of the acquisition operation, the pulse output unit outputs the timing pulse to the prediction system. The measurement head outputs the workpiece according to a measurement command that is output earlier than the timing of the predetermined time interval by a time difference set in advance by the prediction system and in accordance with the timing of the timing pulse. As a result, the first time when the programmable controller acquires the position data of the measuring head and the second time when the measuring head measures the workpiece according to the measurement command are made to coincide with each other. ing.
Further, a workpiece measuring device in a machine tool according to another aspect of the present invention is attached to an NC device that controls the machine tool and a moving body that moves relative to the workpiece within a machining area of the machine tool. A wired measuring head for measuring the workpiece, a control device for controlling the workpiece measuring device, a first axial direction of the measuring head with respect to a measurement point on the workpiece, and the measuring head scans. A programmable controller that obtains data of at least two axial positions including the second axial direction at regular time intervals from the NC device, and a timing pulse having a pulse interval corresponding to the constant time interval, The pulse output unit for outputting to the measurement head and the pulse output unit and the measurement head are connected in the middle of the wiring for electrically connecting the measurement head or the measurement head. A prediction system provided in the programmable controller, wherein the programmable controller acquires the position data of the measurement head, and at the timing of the acquisition operation, the pulse output unit outputs the timing pulse to the prediction system. The measurement head measures the workpiece in accordance with a measurement command that is output earlier than the timing of the certain time interval by a time difference set in advance by the prediction system and that matches the timing of the timing pulse. As a result, the first time when the programmable controller acquires the position data of the measuring head and the second time when the measuring head measures the workpiece according to the measurement command are matched, and the Acquisition of the position data by a programmable controller The position data of the measuring head obtained by the programmable controller is obtained by repeatedly performing the operation of the workpiece by the measuring head at the time and the predetermined time interval at the same timing. Is output to the control device, and the measurement data of the workpiece measured by the measuring head according to the measurement command output from the prediction system is output to the control device, and the control device is configured to output the position data. 2D shape data or 3D shape data of the workpiece is obtained by performing calculations based on the measurement data and the measurement data.
The control device includes a measurement data storage unit that stores the measurement data, the position data acquired by the programmable controller, and a command of a start address memory provided in the control device and the programmable controller. It is preferable to have a position data storage unit that sequentially reads out and stores the position data read out in this way in accordance with a counter command, and an arithmetic processing unit that performs an operation based on the measurement data and the position data.
When receiving the measurement command, the measuring head preferably measures the workpiece in a non-contact manner by measuring the distance from the measuring head to the workpiece.
The measuring head is preferably arranged in the vicinity of a tool attached to the main shaft of the movable body.
The machine tool according to an embodiment includes a three-axis control for linearly moving the measurement head and the workpiece relatively in three orthogonal axes, and a relative rotation of the measurement head and the workpiece. A processing machine that performs at least one-axis control.
Preferably, the measuring head is able to measure the workpiece inclined relative to its reference axis.
Preferably, a step of measuring the workpiece with the measuring head is provided before the step of machining the workpiece with a tool attached to the spindle, during the machining step or after the machining step, The operation and the measurement operation are continued in order or in the reverse order.
In the workpiece measuring method for a machine tool according to the present invention, a workpiece measuring device used in this method includes an NC device that controls the machine tool and a workpiece relative to the workpiece within a machining area of the machine tool. A wired measuring head attached to a moving moving body for measuring the workpiece, a control device for controlling the workpiece measuring device, and a first measuring head for a measurement point on the workpiece. A programmable controller that obtains data of at least two axial positions including the axial direction and the second axial direction scanned by the measuring head from the NC device at regular time intervals, and corresponds to the constant time intervals A pulse output unit that outputs a timing pulse having a pulse interval to the measurement head, and a wiring that electrically connects the pulse output unit and the measurement head. Or a prediction system provided in the measuring head or the programmable controller, the workpiece measuring method by the workpiece measuring device, wherein the programmable controller acquires the position data of the measuring head, At the timing of this acquisition operation, the pulse output unit outputs the timing pulse to the prediction system, and is output earlier than the timing of the certain time interval by a time difference preset in the prediction system and The measurement head measures the workpiece by a measurement command in accordance with the timing of the timing pulse, and as a result, the programmable controller acquires the position data of the measurement head, and the measurement head Measuring the workpiece according to the measurement command; And time and the match of.
In another method for measuring a workpiece in a machine tool according to the present invention, the workpiece measuring device used in this method includes an NC device for controlling a machine tool, and a workpiece in a machining area of the machine tool. A wired measuring head attached to a relatively moving body for measuring the workpiece, a control device for controlling the workpiece measuring device, and the measuring head for a point to be measured on the workpiece; A programmable controller that acquires data of at least two axial positions including a first axial direction and a second axial direction scanned by the measuring head from the NC device at regular time intervals; and the constant time A pulse output unit that outputs a timing pulse having a pulse interval corresponding to the interval to the measurement head, and wiring that electrically connects the pulse output unit and the measurement head Or a prediction system provided in the measuring head or the programmable controller, the workpiece measuring method by the workpiece measuring device, wherein the programmable controller stores the position data of the measuring head. At the timing of this acquisition operation, the pulse output unit outputs the timing pulse to the prediction system, and the time difference preset by the prediction system is positively advanced from the timing of the fixed time interval. In response to a measurement command that is output and matched to the timing of the timing pulse, the measurement head measures the workpiece, and as a result, the programmable controller acquires the position data of the measurement head, and the first time, The measuring head measures the workpiece according to the measurement command. The operation of acquiring the position data by the programmable controller and the operation of measuring the workpiece by the measurement head at that time are always the same time at the predetermined time. The position data of the measurement head acquired by the programmable controller is repeatedly output at intervals, and the position data of the measurement head output to the control device and measured by the measurement head according to the measurement command output from the prediction system. Measurement data of an object is output to the control device, and the control device obtains two-dimensional shape data or three-dimensional shape data of the workpiece by performing an operation based on the position data and the measurement data. I am doing so.

Since the workpiece measuring device and the method thereof in the machine tool according to the present invention are configured as described above, the NC device can be used on the workpiece without modification or change such as adding a new function to the NC device. The operation of acquiring the data of the position of the measuring head in at least two axial directions with respect to the measurement point and the operation of measuring the workpiece by the measuring head at that time are always repeated at regular time intervals at the same timing. ing. As a result, by processing the minimum necessary measurement data, the workpiece can be two-dimensionally or three-dimensionally measured with high accuracy.
Further, the present invention repeatedly performs the operation of acquiring the position data of the measuring head by the programmable controller and the operation of measuring the workpiece by the measuring head at that time at the same timing and at regular time intervals. Yes. As a result, the measuring head can scan at high speed, the workpiece is measured with high accuracy in a short time, and the machine tool can quickly shift to the machining operation after the measurement.

1 to 6 are views for explaining an embodiment of the present invention, and FIG. 1 is a perspective view of a machine tool provided with a workpiece measuring device of the present invention. It is a schematic block diagram of a workpiece measuring apparatus. It is a wave form diagram for demonstrating this invention. It is a wave form diagram of the workpiece measuring apparatus of a present Example. It is explanatory drawing which shows the measurement state of a workpiece. It is a table | surface which shows the data input into the control apparatus, and the calculation result. 7 to 8F are views for explaining a modification of the present embodiment, and FIG. 7 is a perspective view of another machine tool provided with the workpiece measuring device of the present invention. It is explanatory drawing which shows a workpiece measurement state. It is explanatory drawing which shows a workpiece measurement state. It is explanatory drawing which shows a workpiece measurement state. It is explanatory drawing which shows a workpiece measurement state. It is explanatory drawing which shows a workpiece measurement state. It is explanatory drawing which shows a workpiece measurement state.

In the workpiece measuring apparatus according to the present invention, the programmable controller acquires position data of the measuring head. At the timing of this acquisition operation, the pulse output unit outputs a timing pulse. The measurement head measures the workpiece in accordance with a measurement command that is output earlier than the timing of a certain time interval by a time difference set in advance by the prediction system and that matches the timing of the timing pulse.
By doing so, the first time when the programmable controller acquires the position data of the measuring head is matched with the second time when the measuring head measures the workpiece by the measurement command.
The programmable controller performs an operation of acquiring position data in at least two axial directions of the measuring head with respect to the measurement point on the workpiece. On the other hand, the measuring head performs an operation of measuring the workpiece at that time. These acquisition operation and measurement operation are always repeated at the same timing and at regular time intervals.
As a result, it is possible to perform two-dimensional or three-dimensional measurement of workpieces with high accuracy by processing the minimum necessary measurement data without modifying or changing the NC device by adding new functions. In addition, the measurement head can scan at a high speed to measure the workpiece with high accuracy in a short time, and the machine tool can realize the purpose of promptly shifting to the machining operation after the measurement.

  In the following embodiments and modifications, the case where the machine tool is a vertical machining center and a five-axis machine is shown. The machine tool may be a horizontal machining center, a lathe, a lathe, a grinding machine, or a complex processing machine having a swingable tool spindle.

Hereinafter, an embodiment of the present invention and modifications thereof will be described with reference to FIGS. 1 to 8F.
1 to 6 are views for explaining an embodiment of the present invention, and FIG. 1 is a perspective view of a machine tool provided with a workpiece measuring device of the present invention. FIG. 2 is a schematic configuration diagram of the workpiece measuring apparatus, and FIG. 3 is a waveform diagram for explaining the principle of the present invention.
FIG. 4 is a waveform diagram of the workpiece measuring apparatus of the present embodiment, FIG. 5 is an explanatory diagram showing a workpiece measuring state in the present invention, and FIG. 6 is a table showing data input to the control apparatus and calculation results. is there.

As shown in FIGS. 1 and 2, in this embodiment, a vertical machining center is shown as the machine tool 1. The machine tool 1 includes a bed 2 installed on a floor surface, a column 3 installed on the bed 2, a spindle head 5 having a spindle 4, and a saddle 7 having a table 6. The machine tool 1 is controlled by an NC device (numerical control device) 13.
The spindle head 5 is supported on the front surface of the column 3 and is movable in the vertical direction (Z-axis direction). A tool 18 is detachably attached to the tip of the main shaft 4. The main shaft 4 is supported by the main shaft head 5 so that the center axis thereof is parallel to the Z axis and is rotatable around the center axis.

The saddle 7 is disposed on the bed 2 and is movable in the front-rear horizontal direction (Y-axis direction). A table 6 is arranged on the saddle 7. The table 6 is movable in the left and right horizontal direction (X-axis direction). A workpiece 9 is placed on the table 6. Three orthogonal axes are constituted by the X, Y, and Z axes orthogonal to each other.
The spindle head 5 supported by the column 3 is driven by the Z-axis feed mechanism 10 and moves in the Z-axis direction. The saddle 7 disposed on the bed 2 is driven by the Y-axis feed mechanism 11 and moves in the Y-axis direction. The table 6 placed on the saddle 7 and supporting the workpiece 9 is driven by the X-axis feed mechanism 12 and moves in the X-axis direction.

The NC device 13 controls the Z-axis feed mechanism 10, the Y-axis feed mechanism 11, and the X-axis feed mechanism 12, respectively. The NC device 13 controls an ATC (automatic tool changer) 14 that automatically changes the tool 18 with respect to the spindle 4.
Therefore, the machine tool 1 is a machining center that performs three-axis control for linearly moving the main shaft 4 and the workpiece 9 in the three orthogonal directions of the X, Y, and Z axes. Note that the spindle head 5 and the workpiece 9 may be moved relatively in the X-axis and Y-axis directions, respectively.

The workpiece measurement device 20 includes an NC device 13 that controls the machine tool 1 and a wired measurement head 8. The measuring head 8 is attached to a moving body (here, the spindle head 5) that moves relative to the workpiece 9 within the machining area of the machine tool 1, and measures the workpiece 9.
The workpiece measuring device 20 and the workpiece measuring method using the workpiece measuring device 20 can measure the workpiece 9 in a non-contact (or contact) manner with the measuring head 8 attached to the spindle head 5.

  A housing 19 for housing the measuring head 8 is attached to the front surface 5 a of the spindle head 5. The housing 19 supports the measuring head 8 so that it can be withdrawn and withdrawn. The measuring head 8 protrudes downward from the housing 19 when used, and is housed inside the housing 19 when not used. The measuring head 8 measures the workpiece 9 while being exposed downward from the housing 19. A housing 19 that supports the measuring head 8 may be provided on the side surface or the lower surface of the spindle head 5.

The workpiece measuring device 20 includes a control device (for example, a personal computer or a microcomputer) 23 that controls the workpiece measuring device 20, a programmable controller 25 (hereinafter referred to as a controller 25) that controls the machine tool 1, and a pulse output. A unit 24 and a prediction system 29 are further provided.
The controller 25 is, for example, a PMC (programmable machine controller) or a PLC (programmable logic controller). The controller 25 is included in the NC device 13, but the configuration of the controller 25 is a configuration separated from the NC device 13. The controller 25 may be provided separately and independently outside the NC device 13.
The controller 25 reads and acquires the data of the position of the measuring head 8 relative to the measurement point S on the workpiece 9 from the NC device 13 at regular time intervals ΔT. This position data of the measuring head 8 includes at least two axial directions (Z-axis direction, Z-axis direction) including a first axial direction (Z-axis direction) and a second axial direction (X-axis direction) scanned by the measuring head 8. X-axis direction) position data. This “position in the biaxial direction” is often a position in the Z-axis direction and the X-axis direction orthogonal to each other, but the two axes may not be orthogonal.

The controller 25 has a clock 17. The clock 17 outputs a regular signal at regular time intervals ΔT. The controller 25 reads and acquires data on the position of the measuring head 8 from the NC device 13 in accordance with this signal of the clock 17.
The pulse output unit 24 is provided in the controller 25 and outputs a timing pulse P to the prediction system 29. The timing pulse of the pulse output unit 24 is output to the prediction system 29 via an input / output device (for example, I / O link system, I / O link unit) 39. The input / output device 39 is provided in the controller 25 (or the NC device 13). The prediction system 29 has a function as a delay correction circuit.

As shown in FIGS. 1 to 5, the pulse output unit 24 generates a timing pulse P having a pulse interval (time interval from one pulse to the next pulse) ΔT 1 corresponding to a certain time interval ΔT of the clock 17. Then, the data is output to the measuring head 8 through the wiring 60 via the prediction system 29. The timing pulse P is a “pulse for timing”, and is used for adjusting the timing in the prediction system 29 in this embodiment.
In this embodiment, the constant time interval ΔT of the signal output from the clock 17 is 16 [msec (milliseconds)]. It is preferable that the pulse interval ΔT1 of the timing pulse P is basically 16 [msec], and the pulse interval ΔT1 and the constant time interval ΔT are the same.

The prediction system 29 is connected in the middle of the wiring 60 that electrically connects the pulse output unit 24 and the measurement head 8. Note that the prediction system 29 may be provided in the controller 25, the NC device 13, or the measurement head 8.
A signal F including the measurement command f output from the prediction system 29 is sent to the measurement head 8 attached to the spindle head 5 via the wiring 60. The measurement data B 1 measured by the measurement head 8 is sent to the control device 23 via the wiring 61.

When measuring the workpiece 9 with the workpiece measuring device 20, the controller 25 reads and acquires the position data C 1 of the measuring head 8 from the NC device 13. The controller 25 of the present embodiment acquires data C1 of the position of the measuring head 8 with respect to the measurement point S on the workpiece 9 in the three orthogonal axes directions (X axis direction, Y axis direction, Z axis direction).
The “position of the measurement head 8” is a reference position S1 determined in advance in the measurement head 8, and is, for example, the position of the exit of the laser beam L in the laser oscillator.

Then, the pulse output unit 24 outputs the timing pulse P to the prediction system 29 via the wiring 60 at the same timing as the acquisition operation timing of the controller 25.
The prediction system 29 outputs a signal F including the measurement command f to the measurement head 8 via the wiring 60. In this case, when the timing pulse P is input from the pulse output unit 24, the prediction system 29 outputs the signal F of the measurement command f to the measurement head 8. Then, the measuring head 8 measures the workpiece 9 according to the measurement command f.
This measurement command f is a command that is output earlier than the timing of the constant time interval ΔT by a time difference n set in advance by the prediction system 29. The measurement command f is a command that matches the timing of the timing pulse P.
When the prediction system 29 is provided in the measurement head 8, the pulse output unit 24 outputs the timing pulse P as a signal F to the prediction system 29 in the measurement head 8. Then, the prediction system 29 generates a measurement command f based on the timing pulse P, and a signal F of the measurement command f is output to the measurement head 8. Then, the measuring head 8 measures the workpiece 9 according to the measurement command f.

Thus, the measuring head 8 measures the distance D from the measuring head 8 to the workpiece 9. The measured data B1 is output from the measuring head 8 to the control device 23 via the wiring 61.
As a result, the first time T1 when the controller 25 reads and acquires the position data C1 of the measuring head 8 and the second time T2 when the measuring head 8 measures the workpiece 9 according to the measurement command f are matched. (See symbol H in FIG. 4).
The first time T1 is a time for the controller 25 to acquire position data of the measuring head 8 with respect to the measurement point S on the workpiece 9 in at least two axial directions from the NC device 13 at regular time intervals ΔT. . The first time T1 is not limited to one, but is present at regular time intervals ΔT.
The second time T2 is a time during which the measuring head 8 measures the distance D from the measuring head 8 to the workpiece 9 at regular time intervals ΔT according to the measurement command f. Note that the second time T2 is not limited to one, but is present at every fixed time interval ΔT.

Thus, the operation of acquiring the position data C1 by the controller 25 and the operation of measuring the workpiece 9 by the measuring head 8 at that time are always at the same timing (that is, simultaneously) at regular time intervals ΔT. Repeatedly.
That is, the controller 25 reads and acquires position data C1 of at least two axial directions (Z-axis direction and X-axis direction) of the measuring head 8 with respect to the measurement point S on the workpiece 9 from the NC device 13.
Simultaneously with the operation of the controller 25 and at regular time intervals ΔT, the measuring head 8 measures the distance D from the measuring head 8 to the workpiece 9 at that time.

The position data C1 of the measuring head 8 acquired by the controller 25 is output to the control device 23. The measurement data B1 of the workpiece 9 measured by the measurement head 8 in accordance with the measurement command f output from the prediction system 29 is output to the control device 23 via the wiring 61.
The control device 23 obtains two-dimensional shape data or three-dimensional shape data of the workpiece 9 by performing calculations based on the position data C1 and the measurement data B1.

According to the workpiece measuring device 20 having the above-described configuration and the workpiece measuring method using the device 20, it is not necessary to modify or change the NC device 13 such as adding a new function. The operation of acquiring position data C1 in at least two axial directions (Z-axis direction and X-axis direction) of the measuring head 8 with respect to the measurement point S on the workpiece 9 and the workpiece 9 by the measuring head 8 at that time are obtained. The measurement operation is always repeated at a constant time interval ΔT at the same timing.
As a result, the workpiece 9 can be measured two-dimensionally or three-dimensionally with high accuracy by processing the minimum necessary measurement data B1. Further, since the measuring head 8 can scan at high speed, the workpiece 9 can be measured with high accuracy in a short time, and the machine tool 1 can quickly shift to the machining operation after the measurement.

The controller 25 of this embodiment is provided with a buffer memory 16. The buffer memory 16 temporarily stores the position data C1 of the measuring head 8 read from the NC device 13.
When the controller 25 obtains the position data C 1 of the measuring head 8, the position data C 1 is temporarily stored in the buffer memory 16 and then output from the buffer memory 16 to the control device 23.

The control device 23 includes a measurement data storage unit 21 that stores the measurement data B1, a position data storage unit 26, and an arithmetic processing unit 27.
The position data storage unit 26 stores at least biaxial direction position data C1 acquired by the controller 25 and temporarily stored in the buffer memory 16. The position data storage unit 26 sequentially stores the position data C1 in accordance with a command output from a start address memory (counter) 37 provided in the control device 23 and a command from the latest address counter 38 provided in the controller 25. The position data C1 read out and stored in this way are stored. The two storage units 21 and 26 may be provided separately from the control device 23.
The arithmetic processing unit 27 includes data on the distance D measured by the measuring head 8 (that is, measurement data B1), and position data (Z-axis direction, X-axis direction) acquired by the controller 25 ( The calculation is performed based on the data C1) indicating the position of the measuring head 8.

The controller 25 acquires the position data C1 of the measuring head 8 from the NC device 13 in accordance with a signal output from the clock 17 at regular time intervals ΔT. Thereafter, the controller 25 outputs the position data C1 to the control device 23.
The controller 25 obtains the position data C1 of the measuring head 8 from the NC device 13 at a timing of a signal output from the clock 17 at a constant time interval ΔT, and then temporarily stores it in the buffer memory 16. Thereafter, the position data C1 is sent to and stored in the position data storage unit 26 of the control device 23.

The buffer memory 16 is a ring-shaped memory. The buffer memory 16 temporarily stores the position of the measuring head 8 [position data C1 in three orthogonal directions (X-axis direction, Y-axis direction, Z-axis direction)] according to a command from the latest address counter 38 provided in the controller 25. Remember me.
Therefore, the current position information (coordinates) 53 in the X-axis direction by the operation of the servo motor of the X-axis feed mechanism 12, and the current position information (coordinates) 54 in the Y-axis direction by the operation of the servo motor of the Y-axis feed mechanism 11 The current position information (coordinates) 55 in the Z-axis direction by the operation of the servo motor of the Z-axis feed mechanism 10 is input to the drive unit 56. These position data C1 are output to the buffer memory 16 and temporarily stored therein.

For example, the controller 25 provides current position information 53, 54, 55 in the X-axis direction, Y-axis direction, and Z-axis direction of the measuring head 8 when the first measured point S on the workpiece 9 is measured. Read from the NC device 13. Then, the coordinate values “X1, Y1, Z1” are written in the address “1” of the buffer memory 16.
Next, the controller 25 stores the current position information 53, 54, 55 in the X-axis direction, the Y-axis direction, and the Z-axis direction of the measuring head 8 when the second measured point S on the workpiece 9 is measured. Read from the NC device 13. Then, the next coordinate value “X2, Y2, Z2” is written in the address “2” of the buffer memory 16.
In the same manner, current position information 53, 54, 55 in the X-axis direction, Y-axis direction, and Z-axis direction of the measuring head 8 when the N-th measured point S on the workpiece 9 is measured, The controller 25 reads from the NC device 13. Then, the coordinate values “Xn, Yn, Zn” are written in the address “N” of the buffer memory 16.

In this way, the first to Nth position data C1 of the measuring head 8 are temporarily stored in the buffer memory 16 in order. Thereafter, N or a predetermined number of position data C 1 are simultaneously stored in the position data storage unit 26 of the control device 23.
The buffer memory 16 may be provided at a place other than the controller 25, for example, in the NC device 13. Further, the buffer memory 16 does not have to be ring-shaped, and for example, a memory provided in each of the NC device 13 or the controller 25 can be used.

The control device 23 sequentially stores the measurement data B 1 sent from the measurement head 8 in the measurement data storage unit 21. Further, the position data C1 stored in the buffer memory 16 is sequentially read and the position data is read in accordance with a command output from the start address memory 37 of the control device 23 and a command output from the latest address counter 38 of the controller 25. It is stored in the data storage unit 26.
The arithmetic processing unit 27 performs a calculation based on the position data C1 stored in the position data storage unit 26 and the measurement data B1 stored in the measurement data storage unit 21. Thereby, the two-dimensional shape data or the three-dimensional shape data of the workpiece 9 is obtained.

In the prediction system 29 of this embodiment, the measurement command f for the measurement head 8 is positively advanced by the time difference n set in advance by the prediction system 29 and output to the measurement head 8.
Thus, the operation of acquiring the position data C1 by the controller 25 and the operation of measuring the workpiece 9 by the measuring head 8 at that time are always repeated at the same timing (that is, simultaneously) at regular time intervals ΔT. It is done.

The tool 18 can be stored in a tool magazine. The tool 18 is automatically changed with respect to the spindle 4 and can be attached and detached by the ATC 14 controlled by the NC device 13. Therefore, a step of measuring the workpiece 9 with the measuring head 8 can be provided before the step of machining the workpiece 9 with the tool 18 attached to the spindle 4 (or during or after the machining step). For example, the machining operation and the measurement operation are continued in order or in the reverse order. In other words, the machining operation and the measurement operation can be executed in any combination.
In this way, even if the workpiece 9 is not removed from the table 6 for measurement, the workpiece 9 is immediately attached to the table 6 after being processed, and the workpiece 9 is immediately measured two-dimensionally or three-dimensionally. Can do. Moreover, after the operation | movement which measured the workpiece 9, it can also transfer to the operation | movement which processes the workpiece 9 again.

As a related technique of the present invention, the measuring head 8 may be detachably attached to the main shaft 4. However, when the measuring head 8 is attached to or detached from the main shaft 4, there is a possibility that an error occurs in the measurement with the measuring head 8 before and after the attachment / detachment. Further, when the tool 18 is attached to or detached from the main shaft 4, there is a risk that an error may occur in machining with the tool 18 before and after the attachment or detachment.
On the other hand, in this embodiment, the measuring head 8 is attached to the spindle head 5 and is not attached to the spindle 4. Therefore, the workpiece 9 can be measured with high accuracy by the measuring head 8 while being attached to the main spindle 4 without removing the tool 18. In addition, the workpiece 9 can be processed with high accuracy by the tool 18.
The measuring head 8 is disposed in the vicinity of the tool 18 attached to the spindle 4 of the moving body (here, the spindle head 5). Thereby, the measuring head 8 can measure the workpiece 9 at a position close to the tool 18 with high accuracy.
In addition to the spindle head 5 of the machining center, the moving body of the machine tool to which the measuring head 8 is attached is a table 6, a saddle 7, a lathe tool turret and a turret, and a swingable tool spindle in a multi-task machine. May be.

The measuring head 8 includes a laser oscillator that generates a laser beam L for irradiating the surface of the workpiece 9. The laser beam L generated by the laser oscillator is applied to the measurement point S on the surface of the workpiece 9. The measurement head 8 calculates the distance D from the measurement head 8 to the workpiece 9 by receiving the laser beam L reflected from the surface of the workpiece 9.
This distance D is the direction of the reference axis CL (for example, the central axis CL of the laser beam L emitted from the measuring head 8) between the reference position S1 of the measuring head 8 and the measured point S on the workpiece 9. This is the distance in the Z-axis direction.
In the present embodiment, the signal F of the measurement command f is sent from the pulse output unit 24 to the measurement head 8 via the prediction system 29 in a wired manner. When the measuring head 8 receives the signal F of the measurement command f output from the prediction system 29, the measuring head 8 generates a laser beam L by a laser oscillator and irradiates the workpiece 9 with the laser beam L.
Since the laser beam L is reflected at the measurement point S on the workpiece 9, the distance D from the measuring head 8 to the workpiece 9 is calculated based on the reflected laser beam L. Measurement data B 1 including the calculated distance D and the like is output to the control device 23 via the wiring 61.
Thus, when receiving the measurement command f, the measuring head 8 measures the workpiece 9 in a non-contact manner by measuring the distance D from the measuring head 8 to the workpiece 9. Since the measuring head 8 does not contact the workpiece 9 during the measurement operation, the measuring head 8 is scanned at high speed safely and without vibration (or low vibration), and the workpiece 9 can be scanned over a wide range in a short time. Can be measured.

The controller 25 having the pulse output unit 24 and the control device 23 are separated from the NC device 13.
In the workpiece measuring device 20, the controller 25 and the control device 23 are separated from the NC device 13. Therefore, the work measuring device 20 can be designed and changed independently and freely without being constrained by the design criteria and configuration of the NC device 13.

Next, the principle of the present invention will be described.
1, 2, and 3, the premise of the present invention is that the prediction system 29 is not provided and the following conditions 1 and 2 are satisfied. The horizontal axis of the waveform diagram shown in FIG.

(Condition 1): It is assumed that the clock 17 of the controller 25 outputs a signal Pa for obtaining position data from the NC device 13 at regular time intervals ΔT. Then, it is assumed that the controller 25 has read and acquired the position data of the measuring head 8 from the NC device 13 at time t 1 according to the signal Pa of the clock 17.
(Condition 2): It is assumed that the pulse output unit 24 outputs a timing pulse Pb having the same pulse interval as the time interval ΔT of the signal Pa to the measurement head 8 at the same timing as the acquisition operation timing of the controller 25.

The timing pulse Pb output from the pulse output unit 24 at time t 1 flows through the input / output device 39 and the wiring 60 and reaches the measuring head 8.
Thus, at time t2 immediately after the timing pulse Pb reaches the measuring head 8, the measuring head 8 measures the distance D to the workpiece 9 based on the timing pulse Pb.
In the path through which the timing pulse Pb flows to the measuring head 8, there are a circuit of the input / output device 39 and a wiring 60. As a result, a relatively long “delay time” is required from the time when the pulse output unit 24 outputs the timing pulse Pb to the time when the distance D is measured by the measuring head 8.

The delay time Δn from when the timing pulse Pb is output from the pulse output unit 24 to the measuring head 8 at time t1 and until the distance D is measured by the measuring head 8 at time t2 is expressed by the following equation. Is calculated by

Δn = t2 -t1 (1)

On the other hand, the controller 25 reads and acquires the position data of the measuring head 8 from the NC device 13 at time t 1 according to the signal Pa of the clock 17.
That is, the controller 25 acquires data on the position of the measuring head 8 in at least two axial directions with respect to the measurement point S on the workpiece 9 at time t1. In this embodiment, position data X, Y, and Z in the three orthogonal axes directions are acquired.
Since the clock 17 is built in the controller 25 in the NC device 13, the delay time becomes almost zero. Therefore, the controller 25 immediately acquires the position data of the measuring head 8 from the NC device 13 according to the signal Pa at time t1.

A delay time Δn when the measuring head 8 measures the distance D to the workpiece 9 and a delay time (zero in this case) when the controller 25 acquires position data of the measuring head 8 in the three orthogonal axes directions. The difference can be calculated by the following equation as a time difference n which is a predetermined parameter.

n = Δn −0 (2)

Thus, the time difference n is calculated based on FIG. 3 and the above equation (2). This time difference n is a unique value in a system in which the measuring head 8 is attached to the spindle head 5 of the machine tool 1. Therefore, unless the machine tool 1 and the measuring head 8 are partially modified or replaced, the system-specific time difference n is theoretically a constant value.
Therefore, after installing the machine tool 1 and specifying the measuring head 8 to be used, the time difference n is set by one test operation. Depending on the user of the machine tool 1, the time difference n may be confirmed and changed once or a plurality of times each time the machining condition for the workpiece 9 changes or the type of the workpiece 9 changes. In this way, a more accurate time difference n is set.

In the present invention, as shown in FIGS. 1, 2, and 4, the measurement head 8 causes the workpiece 9 to respond to the measurement command f that is output earlier than the timing of the constant time interval ΔT by the time difference n described above. Is measuring. The horizontal axis of the waveform diagram shown in FIG. 4 is time t.
This time difference n is preset by the prediction system 29 connected in the middle of the wiring 60 and is stored in the prediction system 29.
On the other hand, the signal Pa output from the clock 17 has a fixed time interval ΔT.
As a result, the first time T1 when the controller 25 acquires the position data of the measuring head 8 and the second time T2 when the measuring head 8 measures the workpiece 9 are made to coincide (reference numeral in FIG. 4). H).

Next, a procedure for measuring the workpiece 9 with the workpiece measuring device 20 will be described.
First of all, the measuring head 8 is called by the measuring program. Then, the spindle head 5 is moved, and the measuring head 8 attached to the spindle head 5 is positioned at the starting point of measurement (scanning).
Next, the NC device 13, the controller 25, the control device 23, the prediction system 29, etc. are brought into a measurement preparation state by an M code command in the measurement program. The measuring head 8 starts to move above the workpiece 9 according to the movement command of the measurement program.

The controller 25 performs current position information 53, 54 of each axis (X, Y, Z axis) of the measuring head 8 from the NC device 13 at regular time intervals ΔT (16 [msec]) according to the signal Pa of the clock 17. , 55 (position data C1). The position data is sequentially stored in the buffer memory 16 at the first time T1.
At the same time that the controller 25 performs this reading operation (acquisition operation), the pulse output unit 24 outputs the timing pulse P to the prediction system 29. Since this timing pulse P flows through the input / output device 39 and the wiring 60, it is input to the prediction system 29 with a slight delay.
When the first pulse signal Po is input to the prediction system 29, the first pulse signal Po becomes a measurement start command and is output to the measurement head 8, and the measurement head 8 starts a measurement operation. Thereafter, a measurement command f is transmitted to the measurement head 8.
The measurement command f is output earlier than the timing of the constant time interval ΔT by the time difference n set in advance by the prediction system 29. At this time, the timing pulse P is used to synchronize the timing of the measurement command f so that a “time shift” does not occur. That is, the timing gradually shifts after a long time has elapsed, but the timing pulse P prevents the occurrence of this time shift.

Upon receiving the measurement command f from the prediction system 29, the measurement head 8 measures the distance D from the measurement head 8 to the workpiece 9, and transmits the measurement result (measurement data B1) to the control device 23 via the wiring 61. To do. At this time, the signal F of the measurement command f output from the prediction system 29 is transmitted to the measurement head 8 via the wiring 60 and processed in the measurement head 8.
After the time Δn1 necessary for the processing in the input / output device 39, the wiring 60, and the processing in the measuring head 8 has elapsed, the measuring head 8 measures the distance D at the second time T2 in accordance with the measurement command f. .
In this case, the above-described time difference n is set in advance so that the timing at which the measuring head 8 measures the distance D and the timing at which the controller 25 reads the position data C1 of the measuring head 8 coincide (reference numeral H in FIG. 4). ing.
As a result, the first time T1 and the second time T2 become the same time. The measurement operation by the measurement head 8 and the position data reading operation by the controller 25 are always performed at the same timing.

The measurement data B1 output from the measurement head 8 is transmitted to the control device 23 and sequentially stored in the measurement data storage unit 21.
Each time the controller 25 reads the position data of the measuring head 8 from the NC device 13 and additionally stores it in the buffer memory 16, the numerical value of the latest address counter 38 of the controller 25 is incremented by one. The address written last is held in the buffer memory 16.

The control device 23 sequentially reads a series of position data C1 stored in the buffer memory 16 and sequentially stores it in the position data storage unit 26. At this time, the start address of a series of position data to be read in the buffer memory 16 is held in the start address memory 37 of the control device 23, and the value of the start address memory 37 is updated each time the position data is read. deep.
Further, the last address of a series of position data to be read is indicated by the latest address counter 38 of the controller 25.

When the M code command in the program is output, the control device 23 outputs a measurement end command to the controller 25. Then, the measurement by the workpiece measuring device 20 is finished, and the pulse output unit 24 finishes outputting the pulse signal of the timing pulse P. At the end of this output, if the prediction system 29 does not receive a pulse signal after time ΔT (16 [msec]), it is determined that the measurement is completed.
Then, the first position data (X0, Y0, Z0) is deleted from the series of position data C1 stored in the position data storage unit 26 in the control device 23. This is because there is no measurement data corresponding to the first position data at the start of measurement.
Further, the last one measurement data is deleted from the measurement data B1. This is because there is no position data corresponding to the last measurement data.
Next, the arithmetic processing unit 27 obtains position data [(X1, Y1, Z1), (X2, Y2, Z2), (X3, Y3, Z3),..., (Xn, Yn, Zn)] at each time point. And the measurement data (D1, D2, D3,..., Dn) are combined to calculate the two-dimensional shape data or the three-dimensional shape data of the workpiece 9.

In the present invention, the control device 23 may process the minimum necessary measurement data B1. Therefore, the data processing load is reduced, and the memory capacities of the measurement data storage unit 21 and the position data storage unit 26 can be reduced.
Since the NC memory 13 is provided with the buffer memory 16, the position data C1 of the measuring head 8 in the three orthogonal axes directions (X-axis direction, Y-axis direction, Z-axis direction) can be temporarily stored in the buffer memory 16.
Thereafter, a plurality of position data C1 can be collectively stored in the position data storage unit 26 in accordance with a command output from the start address memory 37 of the control device 23 and a command of the latest address counter 38 of the controller 25. Therefore, the burden for the controller 25, the buffer memory 16 and the control device 23 to process the position data C1 can be reduced.

The arithmetic processing unit 27 is based on the minimum necessary measurement data B1 stored in the measurement data storage unit 21 and the position data C1 in the three orthogonal directions of the measurement head 8 stored in the position data storage unit 26. To perform the operation. Thereby, the two-dimensional shape data or the three-dimensional shape data of the workpiece 9 is obtained.
In this way, data (two-dimensional shape data or three-dimensional shape data) of each coordinate of a large number of measurement points S on the workpiece 9 is calculated. The data of the coordinates of the large number of points to be measured S are output to an arithmetic device (for example, a personal computer) 28 provided separately from the control device 23. The calculation device 28 performs a calculation to collect the coordinates of a large number of points S to be measured, thereby obtaining a three-dimensional view of the workpiece 9, that is, a three-dimensional shape E (FIG. 5).

  FIG. 6 shows the result of calculation based on the data B1 of the measurement distance D input from the measurement head 8 to the control device 23, the position data C1 in the three orthogonal directions, and the data B1 and the position data C1 of the measurement distance D. It shows. This calculation result is three-dimensional shape data (that is, the coordinates of the measurement point S on the workpiece 9).

As described above, the workpiece measuring apparatus 20 according to the present invention uses the measurement command f that is output earlier than the timing of the constant time interval ΔT by the time difference n set in advance by the prediction system 29 in accordance with the measurement head f. 8 measures the workpiece 9.
As a result, the first time T1 when the controller 25 acquires the position data of the measuring head 8 and the second time T2 when the measuring head 8 measures the workpiece 9 according to the measurement command f are synchronized.

Thereby, the control device 23 performs arithmetic processing based on the position data C1 of the measuring head 8 in the three orthogonal axes directions and the minimum necessary measurement data B1. Therefore, two-dimensional shape data or three-dimensional shape data of the workpiece 9 can be obtained. As a result, a highly accurate two-dimensional shape or three-dimensional shape of the workpiece 9 is obtained.
The measuring head 8 measures the workpiece 9 without contact. Therefore, the workpiece 9 can be scanned over a wide range in a short time by scanning the measuring head 8 at high speed safely and without vibration (or low vibration).

  In the above description, the pulse output unit 24 outputs the timing pulse P at a pulse interval of 16 [msec]. Since this timing pulse P is used to check the timing of data acquisition, the pulse interval and the measurement interval are not limited and may be arbitrary values.

Regarding the end of the measurement by the workpiece measuring device 20, if the pulse signal of the timing pulse P is not input to the prediction system 29 at a preset pulse interval (16 [msec]), the prediction system 29 determines that the measurement is ended. To do.
By the way, in this determination method, it is assumed that the pulse interval is a long value (for example, 160 [msec]). In this case, even if the controller 25 receives the measurement end command from the control device 23, the measuring head 8 does not receive the timing pulse P after a long time of 160 [msec] until the measuring head 8 recognizes that the timing pulse P does not come. Then, the workpiece 9 is measured and the measurement data B1 is continuously output to the control device 23. As a result, the measurement data B1 acquired by the control device 23 immediately before the end of measurement is wasted.
Therefore, the control device 23 transmits a measurement end command not only to the controller 25 but also to the prediction system 29. When the prediction system 29 receives the command, the measurement head 8 ends the measurement. Is preferred. In this way, there is no inconvenience that the control device 23 acquires unnecessary data immediately before the end of the measurement and causes waste.

Next, a modification of the present embodiment will be described.
7 to 8F are diagrams for explaining modifications of the present embodiment. FIG. 7 is a perspective view of another machine tool 101 provided with the workpiece measuring device 20, and FIGS. 8A to 8F are explanatory views showing a workpiece measuring state, respectively.
The machine tool 101 is a 5-axis control processing machine, and is a multi-tasking machine capable of turning at least the workpieces 9 and 9x based on a 5-axis control vertical machining center.

The 5-axis control machine tool 101 includes three-axis control for linearly moving the tool 18 and the measuring head 8 and the workpieces 9 and 9x in the three orthogonal directions of the X, Y, and Z axes, 18 and the measuring head 8 and the workpieces 9 and 9x are relatively rotated and indexed to perform at least one-axis control (in this example, two-axis control including B-axis control and C-axis control).
If the machine tool 101 is provided with the workpiece measuring device 20, the measuring head 8 and the workpiece can be rotated relatively. Therefore, the workpiece can be measured two-dimensionally or three-dimensionally in a wide range by freely measuring the upper surface, side surface, inclined surface, and the like of the workpiece with the measuring head 8.

The machine tool 101 includes a base body 102, a column 103 installed on the base body 102, a cross rail 107 installed on the column 103, and a spindle head 105 attached to the cross rail 107 and having a spindle 104. Yes. The machine tool 101 is controlled by the NC device 13 (FIG. 2).
The column 103 is disposed on the base 102 and is movable in the front-rear horizontal direction (Y-axis direction). The cross rail 107 is disposed on the column 103 and is movable in the left and right horizontal direction (X-axis direction). The spindle head 105 is supported by the cross rail 107 and is movable in the vertical direction (Z-axis direction). Three orthogonal axes are constituted by the X, Y, and Z axes orthogonal to each other.
A tool 18 is detachably attached to the tip of the main shaft 104. The main shaft 104 is supported by the main shaft head 105 so that its center axis is parallel to the Z axis and is rotatable about the center axis.

  The column 103 arranged on the base body 102 is driven by the Y-axis feed mechanism and moves in the Y-axis direction. The cross rail 107 disposed on the column 103 is driven by the X-axis feed mechanism and moves in the X-axis direction. The spindle head 105 supported by the cross rail 107 is driven by the Z-axis feed mechanism and moves in the Z-axis direction.

The machine tool 101 includes a table 106 that can be turned by B-axis control and that can be rotated by C-axis control. The table 106 can be indexed by rotating the workpieces 9 and 9x relative to the measuring head 8 by B-axis control and C-axis control. The B axis is parallel to the Y axis direction, and the C axis is the rotation center of the table 106.
The spindle head may turn with respect to the table by B-axis control or C-axis control.

As shown by an arrow K, the base 102 is provided with a turning plate 109 that turns by B-axis control. A table support 110 that protrudes forward from the revolving plate 109 and supports the table 106 is fixed to the revolving plate 109.
The table drive device has a B-axis drive device 111 for turning the table 106 by B-axis control, and a C-axis drive device 112 for rotating the table 106 by C-axis control.
By driving the B-axis drive device 111, the swivel plate 109, the table support 110, the table 106, the workpieces 9, 9x, and the like are swung by the B-axis control and indexed to predetermined positions.
By driving the C-axis drive device 112, the table 106 to which the workpieces 9, 9x are attached is indexed by a desired angle rotation by the C-axis control, and can be continuously rotated.

At the time of turning, when the C-axis driving device 112 is driven, the table 106 and the workpieces 9 and 9x are rotated by the C-axis control. Thus, in a state where the workpieces 9 and 9x are placed on the table 106, the workpieces 9 and 9x are rotated at a predetermined rotation speed by the C-axis control. In this way, the workpieces 9 and 9x are turned by the turning tool attached to the spindle 104.
On the other hand, when a rotary tool is mounted on the spindle 104 and cutting is performed with the rotary tool, the C-axis drive device 112 is controlled. The workpiece 9, 9x on the table 106 is indexed to a predetermined position by the C-axis control by the C-axis drive device 112. In this state, the workpieces 9 and 9x placed on the table 106 are cut by the rotary tool of the main shaft 104.

The workpiece measuring device 20 provided in the machine tool 101 has the same configuration as the workpiece measuring device 20 provided in the machine tool 1.
The measuring head 8 is a wired measuring head for measuring the workpieces 9 and 9x. The measuring head 8 is attached to a spindle head 105 as a moving body that moves relative to the workpieces 9 and 9x within the machining area of the machine tool 101. Therefore, the measuring head 8 moves linearly relative to the workpieces 9 and 9x in the three orthogonal directions of the X, Y, and Z axes.
The measurement head 8 is attached to the front surface of the spindle head 105, but may be attached to another part of the spindle head 105 or a moving body other than the spindle head 105.
The workpiece measurement device 20 in the machine tool 101 and the workpiece measurement method using the workpiece measurement device can measure the workpieces 9 and 9x in a non-contact (or contact) manner by the measurement head 8 attached to the spindle head 105. It is.

For example, when the workpiece 9 is rectangular, as shown in FIG. 8A, the B-axis driving device 111 and the C-axis driving device 112 are controlled to position the table 106 horizontally. Thus, when the workpiece 9 is not turning, the measuring head 8 can measure the upper surface 9 a of the workpiece 9 on the table 106.
Next, the B-axis drive device 111 is driven, and the turning plate 109, the table support 110, the table 106, and the workpiece 9 are moved from the state shown in FIG. 8A to +90 degrees by B-axis control as shown in FIG. 8B. Turn and index. Then, the first side surface 9 b of the workpiece 9 on the table 106 can be measured with the measuring head 8.

  Further, by driving the B-axis drive device 111, the swivel plate 109, the table support 110, the table 106, and the workpiece 9 are moved from the state shown in FIG. 8A to +270 degrees by B-axis control as shown in FIG. 8C. Turn and index. Then, the measurement head 8 can measure the second side surface 9c of the workpiece 9 on the table 106 (the side surface opposite to the first side surface 9b).

  In the state shown in FIG. 8B or FIG. 8C, the C-axis drive device 112 is driven, and the swivel plate 109, the table support 110, the table 106, and the workpiece 9 are controlled as shown in FIG. 8D. Turn 90 degrees to find out. Then, the measurement head 8 can measure the third side surface 9d (the side surface perpendicular to the first side surface 9b and the second side surface 9c) of the workpiece 9 on the table 106.

The machine tool 101 performs B-axis control for turning and indexing a workpiece. As a result, as shown in FIGS. 8E and 8F, even when the workpiece 9x has the inclined surface 9e, the measuring head 8 measures the workpiece 9x inclined relative to the reference axis CL. can do.
For example, in the workpiece measurement state shown in FIG. 8E, the table 106 is positioned horizontally without turning by the B-axis control. As indicated by the arrow M, the measuring head 8 is moved along the inclined surface 9e of the workpiece 9x. Thus, the measurement head 8 performs measurement while irradiating the laser beam L obliquely relative to the inclined surface 9e.
Next, in the workpiece measurement state shown in FIG. 8F, the table 106 is turned by the B-axis drive device 111 by the B-axis control so that the entire workpiece 9x is inclined so that the inclined surface 9e is horizontal. Then, the measuring head 8 performs the measurement while irradiating the inclined surface 9e with the laser beam L at a right angle.

As described above, the workpiece measuring device 20 is provided in the 5-axis control machine tool 101. In this way, in addition to the upper surface 9a of the workpieces 9 and 9x, the side surfaces 9b, 9c and 9d, the inclined surface 9e and the like can be freely measured with the measuring head 8, and the workpieces 9 and 9x can be two-dimensionally measured in a wider range. Measurement or three-dimensional measurement can be performed.
The workpiece measuring device 20 provided in the machine tool 101 also has the same effect as the workpiece measuring device 20 provided in the machine tool 1.

As yet another modification, the wired measuring head 8 may be detachably attached to the main shaft 4 of the machine tool 1 or the main shaft 104 of the machine tool 101. In this case, when measuring the workpiece, after the tool is removed from the main shaft by the ATC, the operator manually attaches or removes the measuring head 8 to or from the main shaft.
As a result, if the controller 25 is modified for an existing machine tool, the workpiece measuring device 20 of the present invention can be applied even to this existing machine tool.

Although the embodiments of the present invention (including modifications, the same applies hereinafter) have been described above, the present invention is not limited to the above-described embodiments, and various modifications and additions can be made within the scope of the present invention. Is possible.
In the drawings, the same reference numerals denote the same or corresponding parts.

  The workpiece measuring apparatus and method for a machine tool according to the present invention can be applied to machine tools such as lathes, lathes, and grinders in addition to machining centers and multi-task machines, and are non-contact (or contacted). The workpiece can be measured.

1 Machine tool (vertical machining center)
4,104 Spindle 5,105 Spindle head (moving body)
8 Measurement Head 9, 9x Workpiece 13 NC Device 18 Tool 20 Workpiece Measurement Device 21 Measurement Data Storage Unit 23 Control Device 24 Pulse Output Unit 25 Programmable Controller 26 Position Data Storage Unit 27 Calculation Processing Unit 29 Prediction System 37 Start Address Memory 38 Latest address counter 60 Wiring 101 Machine tool (5-axis machine)
B1 Measurement data C1 Position data f Measurement command n Time difference P Timing pulse S Measurement point T1 First time T2 Second time X-axis direction Second-axis direction Z-axis direction First-axis direction ΔT Constant time interval

Claims (7)

An NC device for controlling the machine tool;
A wired measuring head attached to a moving body that moves relative to the workpiece within the machining area of the machine tool and measures the workpiece;
A control device for controlling the workpiece measuring device;
Data of at least two axial positions including a first axial direction of the measuring head with respect to a measurement point on the workpiece and a second axial direction scanned by the measuring head are fixed from the NC device. A programmable controller to acquire every time interval;
A pulse output unit for outputting a timing pulse having a pulse interval corresponding to the certain time interval to the measurement head;
It is connected in the middle of the wiring that electrically connects this pulse output unit and the measurement head, or comprises a prediction system provided in the measurement head or the programmable controller,
The programmable controller obtains the position data of the measuring head;
At the timing of this acquisition operation, the pulse output unit outputs the timing pulse to the prediction system,
The measurement head measures the workpiece according to a measurement command that is output earlier than the timing of the certain time interval by a time difference set in advance in the prediction system and in accordance with the timing of the timing pulse,
As a result, the first time for the programmable controller to acquire the position data of the measuring head and the second time for the measuring head to measure the workpiece according to the measurement command are matched. Workpiece measuring device for machine tools. An NC device for controlling the machine tool;
A wired measuring head attached to a moving body that moves relative to the workpiece within the machining area of the machine tool and measures the workpiece;
A control device for controlling the workpiece measuring device;
Data of at least two axial positions including a first axial direction of the measuring head with respect to a measurement point on the workpiece and a second axial direction scanned by the measuring head are fixed from the NC device. A programmable controller to acquire every time interval;
A pulse output unit for outputting a timing pulse having a pulse interval corresponding to the certain time interval to the measurement head;
It is connected in the middle of the wiring that electrically connects this pulse output unit and the measurement head, or comprises a prediction system provided in the measurement head or the programmable controller,
The programmable controller obtains the position data of the measuring head;
At the timing of this acquisition operation, the pulse output unit outputs the timing pulse to the prediction system,
The measurement head measures the workpiece according to a measurement command that is output earlier than the timing of the certain time interval by a time difference set in advance in the prediction system and in accordance with the timing of the timing pulse,
As a result, the programmable controller matches the first time when the position data of the measuring head is acquired and the second time when the measuring head measures the workpiece according to the measurement command. The operation of acquiring the position data by the controller and the operation of measuring the workpiece by the measuring head at that time are always repeated at the same timing at the predetermined time intervals.
Outputting the position data of the measuring head acquired by the programmable controller to the control device;
Measurement data of the workpiece measured by the measurement head according to the measurement command output from the prediction system is output to the control device;
The control apparatus is configured to obtain two-dimensional shape data or three-dimensional shape data of the workpiece by performing an operation based on the position data and the measurement data. measuring device. A workpiece measuring device in a machine tool according to claim 1 or 2,
The controller is
A measurement data storage unit for storing the measurement data;
The position data acquired by the programmable controller is sequentially read out in accordance with a start address memory command provided in the control device and a latest address counter command provided in the programmable controller. A position data storage unit for storing the position data;
An apparatus for measuring a workpiece in a machine tool, comprising: an arithmetic processing unit that performs an operation based on the measurement data and the position data.   4. The workpiece measuring apparatus for a machine tool according to claim 1, wherein the measuring head is disposed in the vicinity of a tool mounted on a main shaft of the movable body. Workpiece measuring device in machine. A workpiece measuring device in a machine tool according to any one of claims 1 to 4,
Before the step of machining the workpiece with the tool mounted on the spindle, a step of measuring the workpiece with the measuring head is provided during the machining step or after the machining step,
A workpiece measuring apparatus in a machine tool, characterized in that the machining operation and the measuring operation are successively performed or in the reverse order. A method for measuring a workpiece with a workpiece measuring device,
The workpiece measuring device used in this method is
An NC device for controlling the machine tool;
A wired measuring head attached to a moving body that moves relative to the workpiece within the machining area of the machine tool and measures the workpiece;
A control device for controlling the workpiece measuring device;
Data of at least two axial positions including a first axial direction of the measuring head with respect to a measurement point on the workpiece and a second axial direction scanned by the measuring head are fixed from the NC device. A programmable controller to acquire every time interval;
A pulse output unit for outputting a timing pulse having a pulse interval corresponding to the certain time interval to the measurement head;
It is connected in the middle of the wiring that electrically connects this pulse output unit and the measurement head, or comprises a prediction system provided in the measurement head or the programmable controller,
The workpiece measuring method by the workpiece measuring device is:
The programmable controller obtains the position data of the measuring head;
At the timing of this acquisition operation, the pulse output unit outputs the timing pulse to the prediction system,
The measurement head measures the workpiece according to a measurement command that is output earlier than the timing of the certain time interval by a time difference set in advance in the prediction system and in accordance with the timing of the timing pulse,
As a result, the first time for the programmable controller to acquire the position data of the measuring head and the second time for the measuring head to measure the workpiece according to the measurement command are matched. A workpiece measuring method in a machine tool. A method for measuring a workpiece with a workpiece measuring device,
The workpiece measuring device used in this method is:
An NC device for controlling the machine tool;
A wired measuring head attached to a moving body that moves relative to the workpiece within the machining area of the machine tool and measures the workpiece;
A control device for controlling the workpiece measuring device;
Data of at least two axial positions including a first axial direction of the measuring head with respect to a measurement point on the workpiece and a second axial direction scanned by the measuring head are fixed from the NC device. A programmable controller to acquire every time interval;
A pulse output unit for outputting a timing pulse having a pulse interval corresponding to the certain time interval to the measurement head;
It is connected in the middle of the wiring that electrically connects this pulse output unit and the measurement head, or comprises a prediction system provided in the measurement head or the programmable controller,
The workpiece measuring method by the workpiece measuring device is:
The programmable controller obtains the position data of the measuring head;
At the timing of this acquisition operation, the pulse output unit outputs the timing pulse to the prediction system,
The measurement head measures the workpiece according to a measurement command that is output earlier than the timing of the certain time interval by a time difference set in advance in the prediction system and in accordance with the timing of the timing pulse,
As a result, the programmable controller matches the first time when the programmable controller acquires the position data of the measuring head and the second time when the measuring head measures the workpiece according to the measurement command. The operation of acquiring the position data according to the above and the operation of measuring the workpiece by the measuring head at that time are always repeated at the same time interval at the predetermined time interval,
Outputting the position data of the measuring head acquired by the programmable controller to the control device;
Measurement data of the workpiece measured by the measurement head according to the measurement command output from the prediction system is output to the control device;
This control device obtains two-dimensional shape data or three-dimensional shape data of the workpiece by performing an operation based on the position data and the measurement data, and a workpiece measurement method in a machine tool.

Images