JP2009279727A - Workpiece dimension measuring device and machine tool - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a workpiece dimension measuring device capable of generating a more exact correction value or correction efficient according to a material of a workpiece and an environmental temperature, and a machine tool. <P>SOLUTION: This workpiece dimension measuring device is provided with a measuring device 20 and a measured data correction means 21 for correcting the measured value measured by the measuring device 20 by the correction value or the correction efficient to make the measured value into a measurement output value. The measured data correction means 21 has a heat change amount setting means 22 classified by materials for setting a relation between information on the environmental temperature in which the measuring device 20 is installed and heat change amount by the temperature of the material of the workpiece W, a material-environmental temperature input means 23 for inputting information on the material of the workpiece W to be measuring object and information on the environmental temperature, and a correction value generation means 24 for generating the correction value or the correction efficient by referring the information on the material of the workpiece W and the information on the environmental temperature inputted by the material-environmental temperature input means 23 to the set contents of the heat change amount setting means 22 classified by materials. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a workpiece dimension measuring apparatus and a machine tool that can be applied to, for example, those relating to temperature correction in a measurement amplifier and those capable of performing dimension correction corresponding to a temperature change in a machine tool.

Conventionally, various techniques have been proposed and put into practical use for performing a certain correction by looking at a change value such as a temperature measured by a sensor provided on a substrate or a sensor attached to the outside of a machine or device. ing.
For example, a technique is disclosed in which a sensor mounting base that is driven back and forth by a servo motor controlled by an axis control function of an NC device is installed, and a touch sensor for contacting a workpiece is provided on the sensor mounting base (Patent Document 1). ). The sensor mounting base is driven back and forth until the touch sensor comes into contact with the processed workpiece that has been carried to the workpiece mounting table by the gantry loader, and the workpiece dimensions are measured based on the coordinate values at the time of the contact.

As another conventional technique, an error amount is obtained based on a difference between a wear correction amount obtained by measuring a tool whose dimensions are controlled by a blade edge measuring means and a wear correction amount calculated by blade edge measurement. The amount is stored in the storage means as a reference correction amount. Next, for a tool whose dimensions are not managed, a technique for obtaining the correct wear amount of the tool by calculating a value obtained by adding the reference correction amount to this value when the wear amount is obtained by measuring with the blade edge measuring means. It is disclosed (Patent Document 2).
JP-A-5-208345 Japanese Patent Application Laid-Open No. 11-114779

  In the prior art, a value corresponding to the degree of temperature change, that is, a temperature difference is corrected. However, the amount of change in temperature varies slightly depending on the material being made and the material of the workpiece being processed. For example, in a measurement amplifier, the amount of heat change in the material of the workpiece itself may affect the measured value. Even with temperature correction in a machine, the temperature change rate may vary depending on the material of the machine component.

An object of the present invention is to provide a workpiece dimension measuring apparatus capable of generating a more accurate correction value or correction coefficient according to the workpiece material and the environmental temperature.
Another object of the present invention is to provide a workpiece dimension measuring apparatus that corrects a measured value measured by a measuring instrument only when temperature correction is necessary.
Still another object of the present invention is to provide a machine tool capable of increasing the machining accuracy of a workpiece.

  The workpiece dimension measuring apparatus (M1) according to the present invention includes a measuring instrument (20) that measures the dimension of a predetermined portion of the workpiece (W), and a measured value measured by the measuring instrument (20) as a correction value or a correction coefficient. Measurement data correction means (21) for correcting the measurement output value, and the measurement data correction means (21) includes information on the environmental temperature at which the measuring instrument (20) is installed, and the workpiece (W). Material-specific temperature change input means 22 for inputting the information on the material of the workpiece (W) to be measured and the information on the environmental temperature, and setting the relationship with the amount of heat change due to the temperature of the material. Information on the material of the work (W) and the information on the environmental temperature inputted by the means (23) and the material / environmental temperature input means (23) are set in the setting contents of the heat change amount by material (22). The correction value or correction factor in light of Those having a formation corrected value generating means (24).

  According to this configuration, the material-specific heat change amount setting means (22) sets the relationship between the information on the environmental temperature at which the measuring device (20) is installed and the heat change amount due to the temperature of the material of the workpiece (W). Has been. Before measuring the workpiece dimensions, the operator or the like inputs information on the material of the workpiece (W) to be measured and information on the environmental temperature into the material / environment temperature input means (23). Next, the correction value generation means (24) compares the input material information and environmental temperature information with respect to the correction value or the ambient temperature setting means (22) according to the setting contents of the material-specific heat change setting means (22). A correction coefficient is generated. Information on the material of the workpiece (W) includes a coefficient of linear expansion. In this case, a more accurate correction value or correction coefficient according to the material of the workpiece (W) and the environmental temperature can be generated. Using this correction value or correction coefficient, for example, the feed amount of a blade or the like can be corrected. Therefore, even if the amount of change in temperature slightly changes depending on the material of the workpiece (W), a correction value or the like that allows for the amount of change in accordance with the material of the workpiece (W) and the environmental temperature is obtained. be able to.

  The measurement data correction means (21) determines whether or not there has been a temperature change greater than or equal to a predetermined temperature difference, and the measured value measured by the measuring instrument (20) when it has been determined that there has been a temperature change greater than or equal to the predetermined temperature difference. It is also possible to correct this. The predetermined temperature difference may be set arbitrarily. The measurement data correction means (21) constantly or periodically monitors the environmental temperature, and determines, for example, whether or not a predetermined temperature change has occurred from room temperature. If it is determined that there is no temperature change, the measurement data correcting means (21) returns to the temperature monitoring state. When the measurement data correction means (21) determines that a predetermined temperature change has occurred due to the threshold value, the information on the material of the workpiece (W) and the information on the environmental temperature are compared with the set content. Thereby, the correction value generating means (24) generates a correction value or a correction coefficient for the measurement value. A slight temperature difference does not affect the processing error. Therefore, if the temperature is corrected, the correction is not only wasted, but excessive correction causes a decrease in accuracy. In the present invention, the measured value is corrected when the temperature change is equal to or greater than the predetermined temperature difference, so that such a problem is avoided.

  A machine tool including the workpiece dimension measuring apparatus according to claim 1 or 2 may be used. In this case, it is possible to generate a more accurate correction value or correction coefficient according to the material of the workpiece and the environmental temperature, and to correct the feed amount of, for example, a blade using this correction value or correction coefficient. Even when the design of the material of the workpiece is changed or the environmental temperature can be changed variously, the feed amount of the blade or the like can be corrected easily and quickly each time the change is made. Therefore, the machining accuracy of the workpiece can be increased as compared with the prior art. Therefore, the yield of products can be increased, and the production cost can be reduced.

  A workpiece dimension measuring apparatus according to the present invention includes a measuring instrument that measures the dimension of a predetermined part of a workpiece, and a measurement data correcting unit that corrects a measured value measured by the measuring instrument with a correction value or a correction coefficient to obtain a measured output value. The measurement data correction means includes a material-specific heat change amount setting means for setting a relationship between information on the environmental temperature where the measuring instrument is installed and the heat change amount due to the temperature of the workpiece material, and a measurement target. Material / environment temperature input means for inputting information on the material of the workpiece and information on the environmental temperature, information on the material of the workpiece input by the material / environment temperature input means, and information on the environmental temperature are classified according to the material. Correction value generating means for generating the correction value or correction coefficient in light of the setting contents of the heat change amount setting means, so that a more accurate correction value or correction coefficient according to the material of the workpiece and the environmental temperature It can be generated.

The measurement data correction means determines whether or not there has been a temperature change greater than or equal to a predetermined temperature difference, and corrects the measurement value measured by the measuring instrument based on the determination that there has been a temperature change greater than or equal to the predetermined temperature difference. In this case, the measured value measured by the measuring instrument can be corrected only when temperature correction is required.
In the case of a machine tool including the workpiece dimension measuring device according to claim 1 or 2, the machining accuracy of the workpiece can be increased.

  An embodiment of the present invention will be described with reference to FIGS. In this embodiment, an example in which an NC machine tool includes a workpiece dimension measuring device will be described. As shown in FIG. 1, the NC machine tool 1 includes a machine tool mechanism 2 and a control device 3, and a workpiece dimension measuring device M <b> 1 is mainly provided in the control device 3.

The machine tool mechanism 2 will be described.
The machine tool mechanism unit 2 is composed of a turret type lathe and is provided with a turret 6 serving as a tool post. The turret 6 is provided so that the rotational axis is parallel to the main shaft 5 of the main shaft 4. The turret 6 is, for example, a polygonal drum having a front shape, and is provided with a tool station composed of each peripheral surface portion. A cutting tool T such as a cutting tool or a drill is attached to the tool station via a tool holder.

The turret 6 is mounted on the advance / retreat platform 7 so as to be movable back and forth in parallel with the axial direction of the main shaft 5 and to be indexed and rotated. The advancing / retreating platform 7 is configured to be movable back and forth in the axial direction of the main shaft 5, that is, the X-axis direction orthogonal to the Z-axis direction. That is, the advancing / retreating base 7 is driven to advance / retreat by the advancing / retreating drive means 10 having the feed screw 8 and the motor 9. The turret 6 is advanced and retracted in the Z-axis direction by an advancing / retreating drive means 11 mounted on the advancing / retreating platform 7. The rail 12 and the head stock 4 of the advance / retreat platform 7 are installed on a common bed.
In the vicinity of the main shaft 5, for example, a blade tip measuring sensor 13 made of a touch sensor or the like is installed via a sensor support member 14. The sensor support member 14 is installed on the headstock 4 or the bed. With respect to the sensor 13 composed of a touch sensor or the like, the value of the position detector 19 when a contact signal is generated can be detected.

The control device 3 will be described.
The control device 3 is configured by a computer-type numerical control device (NC) and a programmable controller (PC), and the machining control unit 16 decodes and executes the machining program 15. The arithmetic control unit 16 has an axis feed control means 17, and this axis feed control means 17 controls a motor 9 that moves the turret 6 in the X-axis direction.
The servo controller 18 is a means for controlling the motor 9 in response to a command to the axis feed control means 17, and performs feedback control with a detection value of a position detector 19 such as a pulse coder provided in the motor 9.

  The workpiece dimension measuring apparatus M1 includes a measuring instrument 20 and a measurement data correction unit 21. The measurement data correction unit 21 includes a material-specific heat change amount setting unit 22, a material / environment temperature input unit 23, and a correction. Value generating means 24. The measurement data correction unit 21 corrects the measurement value measured by the measuring instrument 20 with a correction value or a correction coefficient to obtain a measurement output value. The measuring instrument 20 measures a predetermined portion of the workpiece W, for example, the dimension of the outer diameter. The measuring instrument 20 includes a measuring instrument main body 20a and a measuring unit 20b. For example, a measuring instrument main body 20 a composed of a touch sensor or the like is provided on one peripheral surface portion of the turret 6. The measuring unit 20b is configured to read the value of the position detector 19 when the measuring instrument main body 20a in the turret 6 contacts the outer diameter surface of the workpiece W. However, the measuring instrument 20 is not limited to this configuration.

  The control device 3 includes a cutting edge measuring unit, and the cutting edge measuring unit includes the cutting edge measuring sensor 13 and a measuring unit 20b. The measuring unit 20 b is configured to read the value of the position detector 19 when the cutting edge of the tool T of the turret 6 contacts the sensor 13. The position detector 19 may directly detect the position of the turret 6.

  In the material-specific heat change amount setting means 22, the relationship between the information on the environmental temperature at which the measuring instrument main body 20 a is installed and the heat change amount due to the temperature of the material of the workpiece W is set. The workpiece W has a different linear expansion coefficient depending on the type of material. In this embodiment, as shown in FIG. 2, the materials having different linear expansion coefficients and the sizes of the workpieces W are grouped, and an arbitrary material and an arbitrary workpiece W are obtained by performing a plurality of tests. Is stored in advance in the internal information database 22a comprising storage means. In this case, the “size” of the workpiece W includes at least one of an outer diameter dimension of the shaft, an inner diameter dimension of the shaft hole, and an axial dimension. As shown in FIG. 1, a temperature sensor 26 capable of measuring the environmental temperature is provided inside the cover 25 in which the workpiece W is gripped in the NC machine tool 1. At the time of performing the test, for example, the environment temperature inside the cover 25 can be raised by processing a test work, and the temperature sensor 26 can accurately measure the environment temperature. However, the ambient temperature may be measured by the temperature sensor 26 by raising the ambient temperature using a heat source (not shown) or the like without processing the workpiece. In this case, it is possible to reduce labor and material cost for processing the workpiece W for testing.

  The material / environment temperature input means 23 is a means for inputting information such as the material of the workpiece W to be measured and the environment temperature. The storage means of the control device 3 stores information on the materials of the plurality of workpieces W that can be processed and information on the sizes of the plurality of workpieces W. As shown in FIG. 3, the operator can select information on the material of a desired workpiece W that is a measurement target and a processing target by operating the operation panel 27 of the machine tool. Further, information on the size of the desired workpiece W can be selected by operating the operation panel 27.

For example, information on the materials of the plurality of workpieces W such as “aluminum, stainless steel, cast iron,...” Is output and displayed on the operation panel 27, and the operator selects and confirms one of them, Information on this one material is stored in a pre-input information database 23a (FIG. 1) comprising storage means so as to be rewritable. As for the information on the size of the desired workpiece W, information on the size of one workpiece W, for example, “outer diameter φ D1 -D2” is stored in the pre-input information database 23 a by operating the operation panel 27. The
Further, information on the environmental temperature measured by the temperature sensor 26 provided in the cover 25 shown in FIG. 1 is stored in the pre-input information database 23a so as to be rewritable. This environmental temperature information is obtained by constantly monitoring the temperature sensor 26, and is rewritten in the pre-input information database 23a every time the environmental temperature changes.

  As shown in FIG. 1, the correction value generating unit 24 uses the material / environment temperature input unit 23 to input the material and size information of the workpiece W and the environmental temperature information into the material-specific heat change amount setting unit. The correction value or the correction coefficient is generated in light of the set content of 22. That is, the correction value generation unit 24 stores the material information of the workpiece W, the size information of the workpiece W, and the environmental temperature information temporarily stored in the pre-input database 23a in the internal information database 22a. In the light of the amount of heat change in the material and the size of the workpiece W, a correction value or a correction coefficient for correcting the measurement value measured by the measuring instrument 20 is generated.

  In this case, the correction value generation means 24 determines whether or not the material information and size information of the workpiece W stored in the pre-input database 23a is in the internal information database 22a. In the determination of “present”, the correction value generating means 24 has a relationship between the environmental temperature information in the internal information database 22a and the amount of heat change due to the temperature of the material of the workpiece W (referred to as individual information). The relationship is used for generating correction values and the like. The correction value generation means 24 can generate a correction value by calculating the temperature change correspondence amount ± individual information.

  If the correction value generating unit 24 determines that the material of the workpiece W stored in the pre-input database 23a is not in the internal information database 22a, for example, the correction value generating unit 24 calculates a linear expansion coefficient that most closely approximates the linear expansion coefficient of the material of the workpiece W. The workpiece W may be automatically selected from the internal information database 22a. As for the information on the size of the workpiece W that is not in the internal information database 22a, the correction value generation unit 24 also provides information on the size of the workpiece W that approximates the size of the workpiece W such as the measurement target (approximate) as described above. (Referred to as information) may be automatically selected from the internal information database 22a.

Next, a correction method for correcting the measurement value will be described with reference to the flowchart of FIG.
The process proceeds to step S1 under the start condition for turning on the main power supply of the NC machine tool 1, and the measurement data correction means 21 determines whether or not the environmental temperature has changed based on the measurement result by the temperature sensor 26 and the measurement value. Determine whether temperature correction is required. The determination in step S1 is always performed with the main power turned on. However, the determination in step S1 may be performed at regular time intervals or intermittently. When the measurement data correction unit 21 determines that the environmental temperature has changed from a predetermined threshold value, it is determined that the temperature correction of the measurement value is necessary, and the process proceeds to step S2. When the measurement data correction unit 21 determines that the environmental temperature is within the threshold value, it is determined that the temperature correction of the measurement value is unnecessary, and the process returns to step S1.

  In step S <b> 2, the measurement data correction unit 21 confirms the environment information, the material of the workpiece W, and the size information of the pre-input information database 23 a. Next, the process proceeds to step S3, and the measurement data correction unit 21 calls the individual information or the approximate information in the internal information database 22a. Next, the process proceeds to step S4, where the correction value generation means 24 calculates the temperature change correspondence amount ± individual information to obtain a correction amount or a correction coefficient, and stores it in the storage means. In step S5, the feed amount of the tool T is corrected using the stored correction value or correction coefficient. That is, the cutting edge of the tool T to be used is measured by the cutting edge measuring means, and the measured value is multiplied by a correction coefficient to obtain the feed amount of the tool T, or the correction value is added to the measured value and the feed is performed. Amount. Thereafter, the processing in steps S1 to S5 is repeated.

  According to the workpiece dimension measuring apparatus M1 described above, the feed amount of the tool T can be corrected using the correction value or the correction coefficient generated by the correction value generating unit 24. Therefore, even when the amount of change in temperature slightly changes depending on the material of the workpiece W, etc., a correction value can be obtained in consideration of the amount of change in accordance with the material of the workpiece W and the environmental temperature. . Even in the case of producing a small quantity of various types of workpieces W, it is possible to obtain correction values that allow for subtle variations in accordance with the materials etc. of each workpiece W and the environmental temperature, so that the machining accuracy is higher than that of the prior art. be able to.

  The measurement data correction unit 21 corrects the measurement value measured by the measuring instrument 20 when it is determined that there has been a temperature change of a predetermined temperature difference or more (for example, a temperature change of 1 degree or more). Only when necessary, the measurement value measured by the measuring instrument 20 can be corrected. If it is determined that there is no predetermined temperature change, the measurement data correction means 21 simply returns to the temperature monitoring state and does not correct the measurement value. Therefore, the calculation processing load of the measurement data correction unit 21 can be reduced, and the measurement value can be corrected quickly. A slight temperature difference does not affect the processing error. Therefore, if the temperature is corrected, the correction is not only wasted, but excessive correction causes a decrease in accuracy. In this embodiment, such a problem is avoided because the measured value is corrected when there is a temperature change greater than a predetermined temperature difference.

  In the case of the machine tool including the workpiece dimension measuring device M1 as in this embodiment, a more accurate correction value or correction coefficient is generated according to the material, size, and environmental temperature of the workpiece W, and this correction is performed. The feed amount of the tool T can be corrected using a value or the like. Even when the design of the material of the workpiece W is changed or the environmental temperature can be changed variously, the feed amount of the tool T can be easily and quickly corrected each time the change is made. Therefore, the processing accuracy of the workpiece W can be increased as compared with the conventional technique. Therefore, the yield of products can be increased, and the production cost can be reduced.

Next, another embodiment of the present invention will be described with reference to FIGS.
In the following description, portions corresponding to the matters described in the above-described embodiment are denoted by the same reference numerals, and overlapping descriptions may be omitted. When only a part of the configuration is described, the other parts of the configuration are the same as those described in the preceding section. Not only the combination of the parts specifically described in each embodiment, but also the embodiments can be partially combined as long as the combination does not hinder.

In another embodiment of the present invention, the present invention is applied to a workpiece dimension measuring device M2 that measures dimensions such as the outer diameter of a workpiece W that has been processed by a lathe body.
That is, the workpiece dimension measuring apparatus M2 is configured by providing a workpiece mounting table 29, a servo motor 30, a workpiece positioning device 31, a touch sensor 32, and the like on a base 28. The servo motor 30 rotates the ball screw 33 and has a pulse coder 34.

A pair of sensor mounting bases 35 and 35 that are separated from each other are screwed onto the ball screw 33 via ball nuts 36, and each sensor mounting base 35 is guided by a guide rod 36 that is arranged in parallel to the ball screw 33. Then, it is advanced and retracted by the rotation of the ball screw 33.
A touch sensor 32 is attached to each sensor mounting base 35, and the contact 32 a faces the upper side of the work mounting base 29 from below through a slit 29 a formed in the work mounting base 29. ing.

The workpiece positioning device 31 is provided with a workpiece abutting portion 38 at the tip of an advancing / retreating rod of an advancing / retreating drive source 37 such as an air cylinder, and the advancing / retreating direction of the contact 32a across the center position on the workpiece mounting table 29. A pair is arranged so as to face each other in a direction orthogonal to the direction.
The NC device 39 controls the entire machine tool together with a programmable machine controller (PMC) 40, and both 39 and 40 are connected by an interface (NC / PC window) 41. The PMC axis control unit 42 of the NC device 39 has an eight-axis control function, and the seven-axis control function is assigned to control the respective axes of the lathe body 43 and the gantry loader 44. The remaining one-axis control function is used to control the servo motor 30 of the workpiece dimension measuring apparatus M2. In the PMC 40, as one of the writing programs, a workpiece diameter calculation program 45 for measuring the outer diameter of the workpiece W on the workpiece mounting table 29 of the workpiece dimension measuring device M2 is prepared. The machining program of the NC device 39 includes a loader control program for loading a machined workpiece into the workpiece dimension measuring device M2 by the gantry loader 44, and a servo motor 30 and a forward / backward drive source 37 of the workpiece dimension measuring device M2 for workpiece measurement. A program to be controlled is added.

  The output of the pulse coder 34 of the workpiece size measuring device M2 is fed back to the PMC axis control unit 42 of the NC device 39, and the detection output of the touch sensor 32 is input to the NC device 39 via the input device 46. A shaft drive command for the workpiece dimension measuring device M2 output from the PMC shaft control unit 42 of the NC device 39 is given to the servo motor 30 via the servo driver 47.

The operation of the above configuration will be described. The workpiece W processed by the lathe body 43 is transferred onto the workpiece mounting table 29 of the workpiece dimension measuring device M2 by the gantry loader 44. The workpiece W placed on the workpiece mounting table 29 is gripped by the workpiece abutting portion 38 by the advance operation of the advancing and retreating rods of the pair of workpiece positioning devices 31 arranged opposite to each other, and the center position on the workpiece mounting table 29 is reached. Is positioned.
Next, until the touch sensor 32 comes into contact with the workpiece W and is turned on, the sensor mounting base 35 is sequentially moved rightward and leftward by the drive of the servo motor 30. The coordinate values when turned on in the right direction and the coordinate values when turned on in the left direction are read from the detection values fed back from the pulse coder 34 of the servo motor 30 to the PMC axis control unit 42, respectively. The outer diameter of the workpiece W is calculated from the difference between these coordinate values.

After the workpiece diameter is calculated, the process shown in the flowchart of FIG. 4 is executed. That is, the measurement data correction means 21 (see FIG. 1) in the NC device 39 determines whether or not the environmental temperature has changed based on the measurement result by the temperature sensor 26 and whether or not the measurement value needs to be corrected. To do. When the measurement data correction unit 21 determines that the environmental temperature has changed from a predetermined threshold value, it is determined that the temperature correction of the workpiece diameter is necessary, and the process proceeds to step S2. Thereafter, similarly to FIG. 4, in step S4 after step S3, the correction value generation means 24 calculates the temperature change correspondence amount ± individual information to obtain the correction amount or the correction coefficient, and stores it in the storage means. In step S5, the tool position is corrected when the next workpiece W is machined using the stored correction value or correction coefficient. However, the next workpiece W is assumed to be the same material and the same size as the current workpiece W being measured. According to this embodiment, there exists an effect similar to embodiment shown in FIG.
The workpiece W that has been measured is unloaded to a predetermined workpiece unloading position by the gantry loader 44. In the workpiece dimension measuring device M2 for which the measurement has been completed, the workpiece positioning device 31 and the touch sensor 32 are retracted to the original standby position.

In each of the above-described embodiments, the configuration in which the workpiece dimension measuring device M1 is provided in the control device 3 or the like of the NC machine tool is shown, but the configuration is not limited to this configuration. For example, the workpiece dimension measuring device M1 may be suitable for a measurement amplifier or the like. In this case, according to the workpiece material and the workpiece size, the dimension of the predetermined portion of the workpiece can be measured more accurately and easily than the conventional measurement amplifier.
As another embodiment of the present invention, the heat change amount of the material of the workpiece W may be stored in the internal information database 22a, and the size information of the workpiece W may not be stored in the internal information database 22a. It is. In this case, the calculation processing load of the measurement data correction unit 21 can be reduced.
The measuring instrument main body 20a of the measuring instrument 20 may be provided independently of another place of the machine tool instead of the peripheral surface portion of the turret 6.
You may provide the workpiece dimension measuring apparatus M1 in the control apparatus of machine tools other than NC machine tool. In this case, the workpiece W may be other than the shaft. For example, in the case of a plate-shaped workpiece, the thickness of the plate, the length of one side, and the like correspond to the “size” of the workpiece.
Moreover, you may provide the workpiece dimension measuring apparatus M1 independently of the control apparatus 3 of a machine tool.

1 is a block diagram showing a conceptual configuration of a workpiece dimension measuring apparatus and the like according to an embodiment of the present invention. It is a figure which shows the internal structure of the thermal change amount setting means according to material of the workpiece dimension measuring apparatus. It is a figure which shows schematically the operating panel of the machine tool which concerns on embodiment of this invention. It is a flowchart showing the correction method which corrects a measured value in steps. It is a conceptual diagram which shows the structure of the workpiece dimension measuring apparatus which concerns on other embodiment of this invention. It is a front view which shows the structure of the machine tool to which the workpiece | work dimension measuring apparatus is applied.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... NC machine tool 20 ... Measuring instrument 21 ... Measurement data correction means 22 ... Material-specific heat change setting means 23 ... Material / environment temperature input means 24 ... Correction value generation means M1, M2 ... Work size measuring device W ... Workpiece

Claims (3)

A measuring instrument that measures the dimensions of a predetermined part of the workpiece, and measurement data correction means that corrects a measurement value measured by the measuring instrument with a correction value or a correction coefficient to obtain a measurement output value;
The measurement data correction means includes a material-specific heat change amount setting means for setting a relationship between information on the environmental temperature where the measuring instrument is installed and the heat change amount due to the temperature of the material of the workpiece.
Material / environment temperature input means for inputting information on the material of the workpiece to be measured and information on the environmental temperature,
The correction value generation for generating the correction value or the correction coefficient based on the setting contents of the material-specific heat change amount setting means for the workpiece material information and the environmental temperature information input by the material / environment temperature input means And a workpiece dimension measuring apparatus.   The measurement data correction means determines whether or not there has been a temperature change greater than or equal to a predetermined temperature difference, and corrects the measurement value measured by the measuring instrument based on the determination that there has been a temperature change greater than or equal to the predetermined temperature difference. The workpiece dimension measuring device described.   A machine tool comprising the workpiece dimension measuring apparatus according to claim 1.

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