JPH1190780A - Thermal displacement amount parameter calculation device for machine tool, machine tool and storage medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To calculate a thermal displacement amount parameter meeting the characteristics or using environment of individual machine tools accurately and easily in a thermal displacement amount parameter calculation device for machine tool which calculates the thermal displacement amount calculating parameter for the thermal displacement amount calculation device for machine tool. SOLUTION: A machining program A is conducted (S11), and the S11 is repeated in any time other than actual measurement timing and completion timing. The actually measured value of the thermal displacement amount of a machine tool is detected each time the actual measurement timing is made (S15), and the machine tool is stopped after the completion timing (S21) is up. Even after stopping, the actual displacement amount is detected each time the actual measurement timing is made (S25), and the same processing is conducted for a machining program B after the termination timing is up. After that, the actual value of the maximum displacement amount is obtained for the machining programs A, B, and based on the average moving distances of the respective machining programs A, B and the respective maximum displacement amounts, a parameter which defines a corresponding relation between the average moving distance and the maximum displacement amount is calculated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus used for an apparatus for calculating the amount of thermal displacement of a machine tool mounted on a machine tool. It is used for a machine tool thermal displacement calculating apparatus that calculates a thermal displacement of a machine tool by referring to a predetermined correspondence that associates the thermal displacement with a machine tool, and calculates a parameter that defines the correspondence. The present invention relates to a thermal displacement parameter calculating device for a machine tool.

[0002]

2. Description of the Related Art Conventionally, processing means for cutting or drilling a work or assembling parts on a substrate, and driving means for changing the relative position between the processing means and a workpiece such as a work or a substrate. There is a machine tool having: Generally, in a machine tool that performs machining such as cutting, a holding mechanism for holding a tool such as a drill or a tap, a spindle drive mechanism for rotating and driving the tool held by the tool, and a feed of the tool in the X-axis direction -Axis feed mechanism for feeding the tool, Y-axis feed mechanism for feeding the tool in the Y-axis direction, Z-axis feed mechanism for feeding the tool in the Z-axis direction, a control device for controlling these feed mechanisms, etc. It has.

As an example, there is a machine tool 10 shown in FIGS. As shown in FIG. 12, the machine tool 10 includes a table 14 for placing a workpiece W (see FIG. 1) inside a splash guard 12 for preventing scattering of cutting chips, such as a drill or a tap. An ATC magazine 16 for tool change, a machine tool main body (hereinafter also simply referred to as a main body) 20, and the like are arranged. In addition, the splash guard 12 is provided with an operation panel 22, a work exchange port 24 for entering and exiting the work W and maintenance, an inspection hatch 26 mainly for maintenance, and the like.

As shown in FIG. 13, a main body 20 has a main shaft 2 for holding a tool T (FIG. 1) such as a drill or a tap.
8, a spindle motor 30 for rotating and driving the spindle 28, and a nut portion 3 containing a large number of steel balls and fixed to the spindle side.
2, a ball screw mechanism 36 including a ball screw 34 inserted into the nut portion 32, a Z-axis motor 38 for rotating and driving the ball screw 34, a guide rail 40 disposed parallel to the ball screw 34, the guide rail 40 and the main shaft 28.
It has a slide 42 and the like connecting the side.

In the main body 20, a Z-axis feed mechanism for feeding in the Z-axis direction is constituted by the ball screw mechanism 36 and the Z-axis motor 38. The ball screw 34 is rotated by the Z-axis motor 38 to rotate the main shaft 28. The movement in the Z-axis direction is performed. Further, the table 14 shown in FIG. 12 can be moved in the X-axis and Y-axis directions, and together with the movement of the main shaft 28 in the Z-axis direction, the relative position of the workpiece W and the tool T in the X, Y, and Z-axis directions. Can be changed.

[0006] In such a machine tool, for example, frictional heat is generated by driving the ball screw mechanism 36, and the ball screw 34 may be extended. Also, other mechanisms generate heat. Such heat generation causes thermal displacement in the machine tool. If this thermal displacement occurs, for example, in the Z-axis direction, errors occur in the depth of the groove formed in the workpiece W, the height of the step, and the like. If the tolerance is sufficiently larger than the amount of thermal displacement, the processing error due to such thermal displacement does not cause much problem, but if not, the thermal displacement needs to be corrected. Therefore, a thermal displacement calculating device for calculating the thermal displacement of the machine tool is provided, and in controlling the driving means according to a predetermined machining program, the driving means is controlled while performing a correction according to the thermal displacement. (For example, JP-A-62-88548).

[0007]

However, in the conventional machine tool thermal displacement calculating apparatus, the thermal displacement is calculated while the machine tool is being driven, so that a system for executing the processing is used. Had to be constantly running. For this reason, the load involved in the calculation process was large. Therefore, the applicant of the present application pays attention to the fact that when the temperature is increased by continuing to drive the machine tool, the heat generation amount and the heat release amount eventually become in a state of equilibrium, and calculating the thermal displacement amount as follows. Proposed. That is, during the operation of the machine tool, the thermal displacement is calculated based on the saturated thermal displacement and the driving time of the machine tool, and when the thermal displacement becomes substantially equal to the saturated thermal displacement, the thermal displacement is thereafter calculated. Is substituted for the value of the saturated thermal displacement (Japanese Patent Application No. 8-2988).
No. 66). In this case, if an accurate saturated thermal displacement amount is given, the thermal displacement amount at each time can be accurately calculated, and the load related to the calculation process can be reduced.

[0008] Further, the applicant of the present invention, when given the value of the saturated thermal displacement (for example, L), the thermal displacement l when the machine tool is driven for t time, l = L · ｛1 -Exp (-γt)｝, or after driving the machine tool until the thermal displacement reaches the saturated thermal displacement L, and then calculating the thermal displacement 1 when the time t has elapsed after stopping the driving. , L = L · exp (−γ′t) (where γ, γ ′ are constants specific to the machine tool).

However, it has been considered that the parameters such as L, γ, γ ′ and the like must be determined based on a large amount of experimental data. In this case, a typical machine tool is driven under a typical use environment to collect the above experimental data, and the parameters determined based on the experimental data are applied to all the machine tools. Therefore, it is not possible to set parameters according to the characteristics of each machine tool and the use environment, and it has been difficult to calculate an accurate value of the thermal displacement according to the use environment and the like.

Therefore, the present invention is used for a machine tool thermal displacement calculating apparatus which calculates a thermal displacement of a machine tool by referring to a predetermined correspondence relationship based on a driving state of the machine tool. The purpose of the present invention is to provide a machine tool thermal displacement parameter calculating device for calculating parameters that define the relationship, in order to accurately and easily calculate the above-mentioned parameters according to the characteristics and operating environment of each machine tool.

[0011]

Means for Solving the Problems and Effects of the Invention In order to achieve the above object, the invention according to claim 1 comprises a processing means for processing a workpiece, and the processing means and the workpiece. A drive means for changing the relative position of the drive machine, and a drive control means for controlling the drive means based on a given machining program, provided on a machine tool, and a drive state detection means for detecting a drive state of the machine tool; Calculating a thermal displacement amount of the machine tool by referring to a predetermined correspondence relationship based on the drive state detected by the drive state detecting means, and controlling the drive means by the drive control means based on the calculated thermal displacement amount. Displacement amount calculating means for providing as a correction value to be considered;
A thermal displacement parameter calculation of a machine tool, which is used for a thermal displacement calculating device of a machine tool having a parameter, and calculates a parameter defining the correspondence relationship referred to when calculating the thermal displacement by the displacement calculating means. A program storage means for storing a plurality of preset machining programs; a program execution means for causing the drive control means to sequentially execute control based on each of the machining programs; and When the control based on the program is executed, the actual measurement value detection means for detecting the actual measurement value of the thermal displacement amount of the machine tool, the driving state of the machine tool corresponding to the machining program, and the actual measurement value detection means detect A parameter calculating means for calculating the parameter based on the actually measured value of the thermal displacement amount.

In the present invention thus configured, the program storage means stores a plurality of preset machining programs, and the program execution means sequentially controls the drive control means based on the machining programs. Let it run. The actually measured value detection means detects an actually measured value of the thermal displacement of the machine tool when the drive control means executes control based on each machining program. Then, the parameter calculation means is based on the driving state of the machine tool corresponding to the machining program and the actual measured value of the thermal displacement detected by the actually measured value detecting means,
Calculate the above parameters.

On the other hand, in the thermal displacement calculating device, the displacement calculating means refers to the correspondence defined by the calculated parameters based on the driving state of the machine tool detected by the driving state detecting means. Is calculated. The calculated thermal displacement is provided as a correction value to be considered when the drive control unit controls the drive unit.

As described above, in the present invention, the drive control means executes control based on a preset machining program. Then, the parameters are calculated based on the actual measured value of the thermal displacement of the machine tool detected when the control based on the machining program is executed and the driving state of the machine tool corresponding to the machining program. Therefore, it is possible to accurately and easily calculate a parameter that defines the correspondence between the driving state of the machine tool and the amount of thermal displacement based on the actually measured value. Further, since the above parameters are calculated based on the actually measured values, the characteristics of the individual machine tools and the influence of the use environment are favorably reflected. Therefore, in the present invention, the above parameters according to the characteristics of the individual machine tools and the use environment can be calculated accurately and easily, and the accuracy of calculating the thermal displacement of the machine tool by the thermal displacement calculator can be improved satisfactorily. be able to.

Further, in the present invention, the control of the drive control means is sequentially executed for a plurality of machining programs, and the above parameters are calculated based on the actually measured values detected when each machining program is executed. For this reason, the above parameters can be provided with good adaptability to a change in the machining program. Therefore, if the thermal displacement amount is calculated using the parameters calculated according to the present invention, even when the machining program is changed or a new machining program is provided, the machining by the thermal displacement amount calculating device can be performed as described above. The accuracy of calculating the thermal displacement of the machine can be improved satisfactorily.

According to a second aspect of the present invention, in addition to the configuration of the first aspect, the program executing means maintains the same amount of heat until the amount of heat generation and the amount of heat radiation are balanced and the amount of thermal displacement becomes a saturated amount of thermal displacement. The control based on the machining program is repeatedly executed by the drive control means, the machine tool is stopped, and after the thermal displacement of the machine tool is eliminated, the control based on another machining program is similarly executed, and the measured value detection means is controlled. Detects at least an actual measurement value of the saturated thermal displacement amount corresponding to each of the machining programs, and the parameter calculating means determines a driving state of the machine tool corresponding to each of the machining programs and a saturation state corresponding to each of the machining programs. On the basis of the actually measured value of the thermal displacement, a parameter that defines the correspondence between the driving state of the machine tool and the saturated thermal displacement is calculated.

The saturated thermal displacement generated when the machining program is repeatedly executed until the heat generation and the heat radiation are balanced has a good correspondence with the driving state of the machine tool corresponding to the machining program. Further, if the amount of the saturated thermal displacement is known, the amount of the thermal displacement of the machine tool can be accurately and easily calculated by the above-described formula or the like. Further, the driving state of the machine tool can be uniquely calculated for each machining program, and if the driving state is the same, substantially the same amount of saturated thermal displacement is obtained even if the machining programs are different. In the present invention, since the parameters that define the correspondence between the drive state of the machine tool and the amount of saturated thermal displacement are calculated, the parameters have better adaptability to changes in the machining program. Can be made. Therefore, in the present invention, claim 1
In addition to the effects of the described invention, the accuracy of calculating the thermal displacement of the machine tool by the thermal displacement calculating device when the machining program is changed or a new machining program is provided can be further improved. The effect occurs.

According to a third aspect of the present invention, in addition to the configuration of the second aspect, the driving state of the machine tool referred to by the parameter calculating means at the time of calculating the parameter, and the saturated thermal displacement amount based on the parameter. The driving state of the machine tool, which defines the correspondence, is an average moving distance of the driving means moving the processing means or the workpiece per unit time.

According to the present applicant, the average moving distance of the drive means moving the processing means or the workpiece per unit time has a good correspondence with the reproducibility extremely high with respect to the saturated thermal displacement. I discovered that. Therefore, in the present invention, the parameter calculating means calculates the average moving distance and the saturated thermal displacement amount based on the average moving distance corresponding to each machining program and the actually measured value of the saturated thermal displacement amount corresponding to each of the machining programs. The parameters that define the correspondence are calculated. Therefore, in the present invention, in addition to the effect of the invention described in claim 2, there is an effect that the accuracy of calculating the thermal displacement of the machine tool by the thermal displacement calculating device can be further improved.

The invention according to claim 4 is the invention according to claim 2 or 3.
In addition to the configuration described above, the actual measurement value detection unit detects an actual measurement value of the thermal displacement amount of the machine tool at predetermined time intervals until the saturation thermal displacement amount is reached, and the parameter calculation unit adds the actual value to the parameter. Calculating, based on the driving time of the machine tool and the actually measured value of the thermal displacement amount detected at each point in time, a parameter that defines a correspondence between the driving time of the machine tool and the thermal displacement amount. And

When the machine tool is driven, the amount of thermal displacement gradually increases and converges to the amount of saturated thermal displacement. Therefore, in the present invention, the actual measurement value detecting means detects the actual measurement value of the thermal displacement amount of the machine tool at predetermined time intervals until reaching the saturation thermal displacement amount, and the parameter calculating means adds Based on the drive time and the actual value of the thermal displacement detected at each point in time, a parameter that defines the correspondence between the drive time of the machine tool and the thermal displacement is calculated. For this reason, in the present invention, in addition to the effect of the invention described in claim 2 or 3, until the thermal displacement of the machine tool reaches the saturated thermal displacement,
There is an effect that the accuracy of calculating the thermal displacement of the machine tool by the thermal displacement calculating device can be further improved.

According to a fifth aspect of the present invention, in addition to the configuration of any of the second to fourth aspects, the actually measured value detecting means stops the machine tool by measuring the actually measured value of the thermal displacement of the machine tool. After that, the thermal displacement is detected every predetermined time until the thermal displacement disappears, and the parameter calculating means calculates, in addition to the parameters, the stop time of the machine tool and the actually measured value of the thermal displacement amount detected at each time. Based on this, a parameter that defines the correspondence between the stop time of the machine tool and the remaining thermal displacement is calculated.

When the machine tool is stopped, the amount of thermal displacement gradually decreases, and finally there is no thermal displacement. Therefore, in the present invention, the actual measurement value detection means detects the actual measurement value of the thermal displacement amount of the machine tool every predetermined time until the thermal displacement disappears after stopping the machine tool, and the parameter calculating means In addition, a parameter that defines the correspondence between the stop time of the machine tool and the remaining thermal displacement is calculated based on the stop time of the machine tool and the actually measured value of the thermal displacement detected at each point in time. For this reason, in the present invention, in addition to the effect of the invention according to any one of claims 2 to 4, the accuracy of calculating the thermal displacement of the machine tool by the thermal displacement calculating apparatus while the machine tool is stopped is further improved. The effect that it can improve is produced. In the present invention, the elimination of thermal displacement does not mean that the thermal displacement does not have a mathematical meaning, but the effect of thermal displacement is set in consideration of the specifications of the machine tool, the tolerance required for the work, and the like. It is within the range of the error.

According to a sixth aspect of the present invention, in addition to the configuration of any of the first to fifth aspects, when the actually measured value detecting means moves relative to a predetermined position with respect to the workpiece, Processing means detecting means for detecting the processing means; processing means moving means for controlling the driving means to relatively move the processing means to a position detected by the processing means detecting means; By means of transportation
The driving amount of the driving means required to relatively move the processing means to a position detected by the processing means detecting means, and the driving amount required when no thermal displacement occurs in the machine tool Are compared with each other, and the actual measurement value is detected based on the comparison result.

In the actually measured value detecting means of the present invention, the processing means is relatively moved by the processing means moving means to a position detected by the processing means detecting means, and then the driving means required for the relative movement is driven. The amount is compared with the drive amount required when no thermal displacement occurs in the machine tool, and an actual measured value of the thermal displacement of the machine tool is detected based on the comparison result. For this reason, it is possible to automatically and easily detect an accurate measured value of the thermal displacement of the machine tool. Further, in the present invention, the processing means detecting means can be a simple one such as a contact type sensor, and the processing means moving means can have a common configuration with the driving means. Therefore, in the present invention, in addition to the effects of the invention described in any one of claims 1 to 5, it is possible to simplify the configuration of the apparatus to reduce the manufacturing cost, and to calculate the parameters more accurately and easily. There is an effect that it can be done.

According to a seventh aspect of the present invention, there is provided a machine tool including the machine tool parameter calculating apparatus according to any one of the first to sixth aspects. As described above, the machine tool of the present invention is provided with the apparatus for calculating a thermal displacement parameter of a machine tool according to any one of claims 1 to 6 in advance. Therefore, when the machine tool is first installed or when the use environment of the machine tool changes, the above parameters are calculated on the spot by the thermal displacement parameter calculation device, and the parameters correspond to the use environment. Can be updated. Further, if the above calculation is performed when the characteristics of the machine tool change over time, the parameters can be updated to those corresponding to the characteristics of the machine tool.

Therefore, in the machine tool of the present invention, the above-mentioned parameters according to the characteristics of the machine tool and the use environment can be calculated accurately and easily, so that the amount of thermal displacement of the machine tool can be accurately calculated. By calculating, the processing accuracy of the workpiece can be improved. According to an eighth aspect of the present invention, there is provided a processing means for processing a workpiece, a driving means for changing a relative position between the processing means and the workpiece, and the driving means based on a given processing program. A drive control means for controlling the drive state, the drive state detection means for detecting a drive state of the machine tool, and a predetermined correspondence relationship based on the drive state detected by the drive state detection means. Calculating a thermal displacement amount of the machine tool, the displacement amount calculating means for providing the thermal displacement amount as a correction value to be considered when the drive control means controls the drive means,
A computer program for calculating a parameter that defines the correspondence that is used for the thermal displacement calculation device of the machine tool having A medium, a machining program storage unit for storing a plurality of preset machining programs; a program execution process for causing the drive control unit to sequentially execute control based on the machining programs; When the control based on the program is executed, the actual measurement value detection process for detecting the actual measurement value of the thermal displacement amount of the machine tool, and the driving state of the machine tool corresponding to the machining program and the actual measurement value detection process are performed. A computer that executes a parameter calculation process of calculating the parameter based on the actually measured value of the thermal displacement. A processing storage unit that stores programs, characterized by comprising a.

Since the storage medium of the present invention is configured as described above, the machining program storage section functions as the program storage means. Further, if a control means such as a computer executes a computer program stored in the processing storage unit of the present invention, a program execution process corresponding to the program execution means, the actual measurement value detection means, and the parameter calculation means according to claim 1 , An actual measurement value detection process and a parameter calculation process can be executed. Therefore, if the control means executes the computer program stored in the present invention, the same effect as the first aspect of the present invention is produced.

Further, if a requirement limited to the invention of claim 2, 3, 4, 5, or 6 is added to the program of each processing stored in the present invention, when the program is executed, The same effect as the invention according to the second, third, fourth, fifth or sixth aspect is obtained. Furthermore, if the storage medium of the present invention is provided in control means such as a computer mounted on the machine tool,
With the machine tool, the same effect as the invention according to claim 7 is produced.

[0030]

Embodiments of the present invention will now be described in detail with reference to the drawings.

[0031]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The mechanical configuration of a machine tool according to this embodiment is as follows.
1 except that the following detector 49 was provided.
2 and FIG. 13, the description of the mechanical configuration of the machine tool 10 will be omitted by using them.

FIG. 1 is a schematic diagram showing the structure of the detector 49. As shown in FIG. 1, the detector 49 is fixed to one corner of the table 14 and generates a contact signal when the tool T held on the main shaft 28 contacts. Further, the detector 49 is configured so that the position on the Z axis can be changed so that measurement can be performed at an optimum position according to the workpiece W.
When the position is changed, data relating to the position on the Z axis stored in the CPU 72 or the like described later is updated.

FIG. 2 shows a machine tool 10 as a first embodiment.
FIG. 2 is a block diagram illustrating a configuration of a control system. As shown in FIG. 2, the control system is a main shaft control system 50 for controlling the rotation of the main shaft 28, a Z-axis control system 60 for controlling the Z-axis position of the main shaft 28, and the center of this control system. The microcomputer section 70 as the machine tool thermal displacement parameter calculating device and the machine tool thermal displacement calculating device of the present invention, the operation panel 2
2, a detector 49, an X-axis control system (not shown) for controlling the X-axis position of the table 14, a Y-axis control system (not shown) for controlling the Y-axis position of the table 14, and the like. Have been.

The spindle control system 50 includes a spindle motor 30 and a spindle servo amplifier 5 for supplying power to the spindle motor 30.
2, and an axis control circuit 54 for controlling the power supplied to the spindle servo amplifier 52. The axis control circuit 54 controls the operation of the spindle servo amplifier 52 in accordance with an instruction from the CPU 72 of the microcomputer unit 70. Z axis control system 60
Are a Z-axis motor 38, a Z-axis servo amplifier 62 for supplying power to the Z-axis motor 38, and a Z-axis servo amplifier 62.
An axis control circuit 64 for controlling the supply power of
The axis control circuit 64 controls the operation of the Z-axis servo amplifier 62 according to an instruction from the CPU 72 of the microcomputer unit 70. Further, an X-axis control system and a Y-axis control system (not shown) have substantially the same configuration as the main axis control system 50 and the Z-axis control system 60.

The microcomputer unit 70 is composed of a one-chip type CPU 72, a RAM 74, a clock 76, etc., having a built-in ROM and an input / output port for storing a control program and the like, and is configured as a well-known microcomputer. The microcomputer unit 70 (strictly, the CPU 72) controls the spindle control system 50, the Z-axis control system 60, and the like in accordance with a machining program corresponding to the machining to be performed on the workpiece W, and performs a predetermined machining on the workpiece W. is there. Further, the microcomputer unit 70 is connected to the operation panel 22 and the detector 49, and the microcomputer unit 70 is connected to the operation panel 22 or the detector 4.
9 to control the display of images and characters on the liquid crystal display of the operation panel 22 by sending a signal to the operation panel 22, control the blinking of LEDs, and the like.

It should be noted that the ROM of the CPU 72 has a processing storage section storing programs for various processing described below,
In the processing, a processing program storage unit that stores processing programs (two types of processing program A and processing program B) used in parameter calculation processing described later is provided.

The RAM 74 is a work area for the CPU 72 as is well known.
A pitch error correction table having the configuration shown in FIG. 3 is provided above. This pitch error correction table is a table for correcting a driving error of the ball screw mechanism 36, for example.

Ball screw mechanism 36 responsible for Z-axis movement
Is the amount of rotation of the ball screw 34 and the amount of movement of the nut 32 due to manufacturing tolerances (ie, the amount of movement of the main shaft 28 in the Z-axis direction).
It is necessary to correct the error since it cannot be avoided. Therefore, an appropriate number of correction points are set (if the length of the ball screw 34 is 500 mm and correction is performed every 20 mm, the number of correction points is 25). An error between the calculated value and the actually measured value is obtained, and a rotation amount (pitch) of the ball screw 34 corresponding to the error is written in a pitch error correction table, and the ball screw 34 is rotated forward or backward by the pitch for each correction point. By doing so, the Z-axis position of the main shaft 28 is accurately adjusted. X axis and Y
The same is true for the axis.

The clock 76 is a so-called electronic clock.
The date can be calculated and the data can be sent to the CPU 72. It should be noted that the CPU 72 has a predetermined period, for example, 1 /
A built-in counter for incrementing the count value every 1000 seconds is provided, and by using the counter, an elapsed time such as a required time from the start to the end of a certain processing can be measured.

When the machine tool 10 is driven, thermal displacement occurs in the Z-axis direction due to expansion of the ball screw 34 and the like. Therefore, in order to execute the machining program while correcting the thermal displacement, the CPU 72 calculates the amount of thermal displacement by the following processes. First, a description will be given of a process in a case where various parameters and a map, which will be described later, required for calculating the thermal displacement amount have already been set (that is, a process of the CPU 72 as the thermal displacement calculating device of the machine tool). FIG. 4 is a flowchart illustrating a thermal displacement calculation process for calculating the thermal displacement of the machine tool 10. Note that the CPU 72 executes this thermal displacement amount calculation process as an interrupt process at a predetermined timing after the power is turned on, and calculates the thermal displacement amount generated by executing a machining program or the like.

As shown in FIG. 4, when the CPU 72 starts the process, first, in S1 (S indicates a step: the same applies hereinafter), the CPU 72 performs a process of regarding the moving distance during power-off as 0. As will be described later, when the amount of thermal displacement has been calculated in the past and its influence still remains, it is necessary to calculate the amount of thermal displacement of the machine tool 10 in consideration of the effect. Also,
The amount of such thermal displacement can be measured by the machine tool 1 during the break time of the factory.
0 may remain even after the power is turned off. Therefore, in S1, the moving distance of the main shaft 28 in the Z-axis direction while the power is turned off is set to zero.

In the following S2, based on the output of the clock 76,
It is determined whether or not a predetermined sampling time (a minute interval) has been reached. If it is not the sampling time (S2: NO), the process stands by, and if it is the sampling time (S2: YES), the process shifts to S3. In S3, the driving state of the machine tool 10 is detected from the execution state of the machining program and the like, and the movement distance of the main shaft 28 in the Z-axis direction during the sampling time is calculated based on the detected driving state. Thereafter, the process proceeds to S4, and the maximum displacement L as the saturated thermal displacement is calculated as follows.

When the temperature is increased by continuing to drive the machine tool 10, the heat generation and the heat radiation eventually balance. The thermal displacement at this time is the maximum displacement L. When the machine tool 10 is continuously driven in a constant state, the maximum displacement L
Has a correspondence relationship shown in FIG. 5 with respect to the average moving distance X of the main shaft 28 per unit time. That is, as shown in FIG. 5, the maximum displacement L increases as the average moving distance X increases. Also, this correspondence is represented by a linear function line. At S4, the moving distance calculated at S3 is calculated as the average moving distance X per unit time (here, mm / min).
, And the corresponding maximum displacement L is calculated with reference to the map of FIG. The map in FIG. 5 may be stored in the CPU 72 in the form of a mathematical expression or a data table.

In S5, the thermal displacement 1 during the sampling time is calculated as follows. As illustrated in FIG. 6, when the maximum displacement is L _1a , the thermal displacement 1 during the driving of the machine tool 10 is the asymptote 10 with respect to the straight line 1 = L _1a .
Draw 2. When the machine tool 10 is stopped after the thermal displacement 1 reaches the maximum displacement L _1a (at time t = 8hour in FIG. 6), the thermal displacement 1 becomes an asymptote 1 with respect to the straight line l = 0.
Draw 04. Here, the asymptote 102 is: l = L _1a · {1-exp (−γt)} (1) and the asymptote 104 is: l = L _1a · exp (−γ′t) (2) ), Respectively. Here, γ and γ ′ are constants unique to the machine tool 10, and the units of t and l are respectively hour and hour.
μm. Therefore, from this equation, the thermal displacement l _1a a minute after the start of driving of the machine tool 10 is given by l _1a = L _1a · {1-exp (−γ · a / 60)}. Also, the thermal displacement l after a minute after the machine tool 10 stops
_-1a is expressed as follows: l _-1a = L _1a · exp (−γ ′ · a / 60) In S5, the thermal displacement amount 1 during the sampling time is calculated mainly using Expression (1). Further, in the subsequent S6, the thermal displacement 1 within the holding time described later is added to calculate the total thermal displacement as follows, and then the process shifts to S2 to wait for the next sampling time.

In this embodiment, the case where the thermal displacement 1 is calculated based on the moving distance during the sampling time (S3 to S3)
5) It is considered that the thermal displacement l subsequently decreases in accordance with the equation (2). That is, as exemplified by the curve 201 in FIG. 7A, the value l _1a-1 of the thermal displacement amount l _{1a at} the time 1a calculated based on the moving distance from the time 0 to the time 1a is as described above. _L1a-1 = L1a ₁ {1-exp (-γ ・ a / 60)}. Here, _L1a is the maximum displacement calculated at the sampling time of time 1a. Then, the value l _1a-2 of the thermal displacement amount l _{1a at} the time 2a is calculated from the equation (2) as follows: l _1a-2 = l _1a-1 · exp (−γ ′ · a / 60) , Thermal displacement l _{1a at} time 4a
The value _{l 1a-3, l 1a-} 4, l 1a-3 = l 1a-1 · exp (-γ '· 2a / 60) l 1a-4 = l 1a-1 · exp (-γ' · 3a / 60). Similarly, if the maximum displacement L _2a is calculated based on the movement distance from time 1a to time 2a,
The corresponding thermal displacement l _2a is shown by curve 202 in FIG.
And the values l _2a-1 , l _2a-2 , and l _{2a-3 at} the times 2a, 3a, and 4a are respectively: l _2a-1 = L _2a · ｛1-exp (−γ · A / 60)｝ l _2a-2 = l _2a-1 · exp (-γ'a / 60) l _2a-3 = l _2a-1 · exp (-γ '2a / 60) At S6, the total thermal displacement is calculated by adding the values of the thermal displacements l _1a , l _2a ,... Thus calculated at that time at that time. For example, at times 1a, 2a,
Based on the moving distances between the sampling times 3a, 4a, 5a,..., The curves 201, 202, 2 in FIG.
Assuming that the thermal displacement 1 exemplified by 03, 204, 205,... Is calculated, the total thermal displacement calculated at S6 changes as illustrated by the curve 200 in FIG.

The thermal displacement l calculated at each time is
As described above, the amount of heat displacement decreases with the lapse of time, so that the influence of the thermal displacement amount 1 after a predetermined time (for example, 120 minutes) calculated in S5 on the total thermal displacement amount can be ignored. Becomes Therefore, the CPU 72 stores the predetermined time in the ROM as the holding time, and calculates the total thermal displacement by performing the above addition only on the thermal displacement 1 calculated within the holding time. Therefore, the number of thermal displacements l that must be added in the process of S6 is 120 / a
This is suppressed to a natural number of +1 or less, and the load related to the calculation process can be reduced. Therefore, it is possible to simplify the software configuration and the like related to the processing and improve the processing speed.

The CPU 72 associates the thermal displacement 1 calculated at each time with the calculated time at the RAM.
74, and the stored contents are stored in the power supply O.
It is also held between the FFs by a backup power supply (not shown). For this reason, the power is once turned off and turned on again.
In step S1, the moving distance during power-off is regarded as 0 (therefore, the thermal displacement 1 is also 0) in S1, and the process proceeds to S6, where the thermal displacement 1 calculated during the previous power-on period is determined. Among them, the total thermal displacement amount can be calculated by adding the influence of those for which the holding time has not elapsed since the calculation.
Next, the map of FIG. 5 and the thermal displacement parameter calculation processing for calculating parameters such as γ and γ ′ (processing of the CPU 72 as the thermal displacement parameter calculation device of the machine tool) will be described. FIG. 8 is a flowchart showing the thermal displacement parameter calculation processing. Note that the CPU 72 executes this processing when the operation panel 22 is operated according to a predetermined procedure. The timing at which this process is executed by operating the operation panel 22 may be performed when the machine tool 10 is manufactured, when the machine tool 10 is installed for the first time, when the machine tool 10 is relocated to a different environment, 1
Various timings are conceivable, such as when a time-dependent change occurs in the characteristic of 0.

When the process is started, the CPU 71 first executes S
At 11, the control for driving the spindle 28, the Z-axis motor 38, and the like according to the machining program A is executed. When the control according to the machining program is executed, the workpiece W may be actually machined, or the spindle 28 or the like may be driven idle without placing the workpiece W on the table 14. In the case of, a similar calculation result is obtained.

Processing program A for one work W
When a series of controls corresponding to the above is completed, the process proceeds to S13, and the following determination is made on the current timing. That is, in this processing program, the actual measurement timing for actually measuring the amount of thermal displacement of the machine tool 10 is set at predetermined time intervals, and the machine tool 10 is stopped after the control of the machining program A is repeated a predetermined number of times. The end timing for the execution is set. In S13, if it is not any of the above-mentioned timings, the process proceeds to S11 and the control of the machining program A is executed again. If it is the actual measurement timing, the process proceeds to S15. If it is the end timing, the process proceeds to S21.
, Respectively. Note that the actual measurement timing may be set to a sufficiently short interval so that even when the machine tool 10 is driven in an extremely hot environment, the thermal displacement does not reach the maximum displacement L until the first actual measurement is performed. . In addition, the end timing may be set to a sufficiently late time point so that the thermal displacement amount reaches the maximum displacement amount L even when the machine tool 10 is driven in an extremely cold environment.

If it is determined in S13 that it is the actual measurement timing, an actual measurement value detection process in S15 is executed. In this process, the Z-axis control system 60, the X-axis control system, and the Y-axis control system are driven to detect the tool T held on the main shaft 28 by the detector 4
Contact 9 The CPU 72 calculates the drive amount of the Z-axis control system 60 required until the contact signal is received from the detector 49 and the above-described contact is confirmed, and is necessary when the thermal displacement does not occur in the machine tool 10. The calculated driving amount is compared with the calculated driving amount. Then, based on the comparison result, the actual measurement value (Z-axis direction) of the thermal displacement amount of the machine tool 10 is detected. After the detection of the actually measured value, the process returns to S11 to execute the control of the machining program A.

If it is determined in S13 that it is the end timing, the process proceeds to S21 to stop the machine tool 10, and then proceeds to S23. In S23, the following determination is made for the current timing. That is, the machine tool 1
It is determined whether it is an actual measurement timing for actually measuring the thermal displacement amount of 0 or an end timing for ending the stop of the machine tool 10 and newly starting the control of the machining program. If it is not any of the above timings, the process waits as it is. If it is the actual measurement timing, the process proceeds to S25, and if it is the end timing, the process proceeds to S31. In S25, the measured value of the thermal displacement of the machine tool 10 is detected in the same manner as in S15, and the process returns to S23. Note that the actual measurement timing may be set to a sufficiently short interval so that even if the machine tool 10 is stopped in a very cold environment, thermal displacement does not disappear until the first actual measurement is performed. Further, the end timing may be set to a sufficiently late time point so that the thermal displacement is eliminated even if the machine tool 10 is stopped in a very hot environment.

If it is determined in S23 that it is the end timing, the flow shifts to S31, and the same processing as in S11 to S25 is executed for the machining program B. That is, the control of the machining program B is executed (S31), and if neither the actual measurement timing nor the end timing is reached, S31 is repeated as it is. Every time the actual measurement timing comes, S35
To detect the actual measured value of the thermal displacement amount of the machine tool 10, and when the end timing comes, the machine tool 10
Is stopped (S41). Even after the stop, the actual measured value of the thermal displacement of the machine tool 10 is detected each time the actual measurement timing comes (S4).
5) When the end timing comes, the process shifts to S51. S5
In step 1, the following parameter calculation process is executed, and the process ends.

FIG. 9 shows the thermal displacement l in the machine tool 10.
5 is a graph showing a change in an actually measured value of S15, S25,
The measured values detected in S35 and S45 are indicated by ■. In the graph of FIG. 9, for convenience of explanation, the change of the measured value of the thermal displacement 1 for the machining program A and the change of the measured value of the thermal displacement 1 for the machining program B are displayed in a superimposed manner.

While the machining program A is repeated (S1
1), the measured value detected in S15 increases along the asymptote 102a and reaches the maximum displacement La. When the machine tool 10 is stopped (S21), the measured value detected in S25 decreases along the asymptote 104a, and the thermal displacement eventually disappears. Here, eliminating thermal displacement does not mean disappearing in a mathematical sense, but the effect of thermal displacement is
This means that the error falls within a range of an error set in consideration of the specifications of the machine tool 10, a tolerance required for the workpiece W, and the like. Similarly, while the machining program B is repeated (S31), S35
The actual measurement value detected at the time increases along the asymptote 102b to the maximum displacement Lb, and when the machine tool 10 is stopped (S4).
1) The measured value detected in S45 decreases along the asymptote 104b. In the ROM of the CPU 72, average moving distances Xa and Xb corresponding to the machining programs A and B are stored.
It is stored in advance together with the machining programs A and B.

Therefore, in S51, a linear function (L = aX +) representing the straight line of the map described with reference to FIG. 5 so that the straight line passes through two points (Xa, La) and (Xb, Lb).
Find the coefficients a and b of b). Also, the asymptote 102 of FIG.
a and 102b are given by l = La · {1-exp (−γt)} (3) and l = Lb · {1-exp (−γt)} (4) Then, in S51, the value of γ is determined so that the error between the curve according to the above equations (3) and (4) and each of the measured values is minimized. Similarly, utilizing that the asymptotes 104a and 104b are given by l = La.exp (-γ't) (5) and l = Lb.exp (-γ't) (6) The value of γ ′ is determined so that the error between the curves according to the above equations (5) and (6) and each of the measured values is minimized. In S51, when the map of FIG. 5 and the values of γ and γ ′ are calculated in this way, the present process ends.

In the present embodiment, the map (coefficients a, b) and γ, γ ′ in FIG.
4 are calculated using the parameters.
Can be executed. Therefore, the parameters according to the characteristics of the individual machine tools 10 and the use environment can be easily calculated, and the calculation accuracy of the total thermal displacement amount by the thermal displacement amount calculating process can be improved satisfactorily.

In this embodiment, the actual measured values of the maximum displacements La and Lb are obtained for a plurality of machining programs (machining program A and machining program B), and the average moving distance Xa, Xb and its maximum displacement L
Based on a and Lb, a parameter that defines the correspondence between the average moving distance X and the maximum displacement L is calculated. The present applicant has discovered that the average moving distance X has a good correspondence with the maximum displacement L with extremely excellent reproducibility. Furthermore, the average moving distance X can be uniquely calculated for each machining program. If the average moving distance X is the same, the maximum displacement L
Are almost the same. For this reason, the thermal displacement amount calculation processing of this embodiment has extremely good adaptability to the change of the machining program, and even when the machining program is changed or a new machining program is provided, the machine tool 10 can be used. Can be calculated very accurately.

In the above embodiment, the maximum displacement L is associated with the average moving distance X. However, the driving state of the machine tool 10 which can be associated with the maximum displacement L is as follows. Elapsed time required to move, number of ATCs (ie, number of tool T changes), spindle 2
8, the number of times of acceleration / deceleration, the amount of rotation of the spindle motor 30 per unit time (the rotation also causes the elongation in the Z-axis direction), and the like.
Various driving states can be adopted. When the elapsed time required for the movement of the main shaft 28 is associated with the maximum displacement L and a map representing the correspondence is obtained based on the actually measured values, the thermal displacement of the machine tool 10 is calculated in the same manner as in the above embodiment. It can be calculated very accurately.

Further, in addition to the maximum displacement amount L in addition to the average moving distance X or the above-mentioned elapsed time, a multidimensional map in which the number of ATCs, the number of times of acceleration / deceleration of the spindle 28, the amount of rotation of the spindle motor 30 per unit time, and the like are taken into account. If the map is set based on the measured values, the amount of thermal displacement of the machine tool 10 can be calculated more accurately. However, when the maximum displacement L is associated with the number of ATCs, the number of times of acceleration / deceleration, or only the amount of rotation, and both the average moving distance X and the elapsed time are ignored, the effects of the present invention are produced temporarily, but the above embodiment The calculation accuracy is not so high.

The map for associating the maximum displacement L with the average moving distance X is not limited to the map illustrated in FIG. 5, but may be a polygonal line illustrated in FIG. 10A or a map illustrated in FIG. 10B. It may be defined by a curve. In particular, when the coefficient b of the straight line (L = aX + b) representing the map calculated by the thermal displacement amount parameter calculation processing of the embodiment is not 0, the map may be represented by the following polygonal line. That is, in the actual machine tool 10, when X → 0, L → 0
Becomes Therefore, for example, the line of the map is bent at a point of X = X0 (X0 is a relatively small set value), and L = aX + b (X ≧ X0) L = (aX0 + b) X / X0 (X ≦ X0) May represent the above map. Further, if three or more types of machining programs are used and three or more sets of the average moving distance X of each machining program and the maximum displacement L actually measured by executing the machining program are acquired, the above-mentioned map can be obtained. It can be defined by a higher-order function such as the following function.

Further, in the above embodiment, in addition to the map for associating the maximum displacement L with the average moving distance X, the machine tool 1
The parameters γ and γ ′ that define the correspondence between the drive time or the stop time of 0 and the amount of thermal displacement are calculated. Therefore, until the thermal displacement reaches the maximum displacement L, and
The accuracy of calculating the amount of thermal displacement while the machine tool 10 is stopped can be further improved. Further, in the above embodiment, the actual measurement value of the maximum displacement L is detected by setting the end timing to a sufficiently late time, but the actual measurement value (S15, S3) of the thermal displacement detected at each actual measurement timing is detected.
When there is no change in 5), the machine tool 10 may be stopped using the measured value as the measured value of the maximum displacement L (S2).
1, S41). Similarly, when there is no change in the measured value (S25, S45) of the thermal displacement amount while the machine tool 10 is stopped,
Execution of another machining program (S31) or parameter calculation processing (S51) may be performed. In these cases, the processing time required for the thermal displacement parameter calculation processing can be reduced.

In the above embodiment, the main shaft 28 is used as the machining means, and the ball screw mechanism 36 and the Z-axis control system 60, X
The axis control system and the Y-axis control system are the driving means and the processing means moving means, the detector 49 is the processing means detecting means, the ROM in the CPU 72 is the program storage means, the CPU 72 is the driving state detecting means, the displacement calculating means, CPU corresponds to program execution means, actual measurement value detection means, and parameter calculation means
Of the processing in S72, S3 corresponds to the driving state detecting means, and S4 to S
6 corresponds to a displacement amount calculating means, S11 and S31 correspond to a program executing means, S15, S25, S35 and S45 correspond to actual measurement value detecting means, and S51 corresponds to a parameter calculating means.

Next, a second embodiment of the present invention will be described. FIG. 11 is a block diagram illustrating a configuration of a control system of the machine tool 10 according to the second embodiment. Note that the machine tool 1 of the present embodiment
The mechanical configuration of the control system 0 is the same as that of the first embodiment, and the configuration of the control system differs in the following points. That is, as shown in FIG. 11, the microcomputer unit 70 includes an interface (I / F) 78 in addition to the above-described configuration, and is connected to the personal computer 80 via the interface 78. The personal computer 80 includes a one-chip type CPU 82 having a ROM for storing a control program and the like, an input / output port, and the like.
It comprises an M84, a clock 86, an interface (I / F) 88 connected to the microcomputer unit 70, and the like, and is configured as a known microcomputer. Further, a keyboard 91 and a CRT 92 are also connected to the personal computer 80. In this control system, the microcomputer unit 70 controls the machine tool 10 based on a machining program.
From 0, the machining programs A, B, etc. are transmitted to the microcomputer unit 70. In addition, the microcomputer unit 70 sends a measured value of the thermal displacement amount detected by using the detector 49 to the personal computer 80, and the like.
Data required for calculating the above parameters is transmitted.

Therefore, in the personal computer 80, the above-mentioned machining programs A and B are sequentially transmitted to the microcomputer unit 70, and the microcomputer unit 70 can control the machine tool 10 corresponding to the machining programs (FIG. 8). S11 and S31). The microcomputer unit 70 includes a machining program A,
During the execution of B and the stop of the machine tool 10, the actual measured value of the thermal displacement amount is detected at the above-described actual measurement timing (S15 in FIG. 8,
(See S25, S35, and S45), and transmit to the personal computer 80. Then, the personal computer 80 executes a parameter calculation process in the same manner as in S51 described above.

In this embodiment configured as described above, the first
Functions and effects substantially similar to those of the embodiment are obtained. In this embodiment, if the machine tool 10 connected via the interface 88 is changed, one personal computer 80 can calculate the thermal displacement amount parameters for a plurality of machine tools 10. On the other hand, in the above-described first embodiment, the thermal displacement amount parameter calculating device of the present invention uses the machine tool 1
Equipped with 0. For this reason, when the use environment is changed by installing or relocating the machine tool 10 for the first time,
If the characteristics of the machine tool 10 change over time, the above parameters can be calculated on the spot. Therefore, the above parameters according to the characteristics of the machine tool 10 and the use environment can be accurately and easily calculated, and thus the thermal displacement of the machine tool 10 is accurately calculated, and the processing accuracy of the workpiece W is improved. Can be improved.

As described above, the present invention has been described with reference to the embodiments. However, the present invention is not limited to the above embodiments, and can be implemented in various forms without departing from the gist of the present invention. . For example, the present invention may be applied to calculation of other parameters not related to the maximum displacement L, or may be applied to a mechanism for moving the table 14.

In each of the above embodiments, the tool T is brought into contact with the detector 49 to detect that the main shaft 28 has moved to a predetermined position, and based on the drive amount of the Z-axis control system 60 at that time, the heat is detected. Although the actual measured value of the displacement amount is detected, various other configurations can be adopted as the actual measured value detecting means. For example, the main shaft 28 can be detected by the detector 4 without using the tool T.
9 may be directly contacted, or the main shaft 28 may be photographed from the side, and the actually measured value of the amount of thermal displacement may be detected by image processing or the like. Further, a dimensional error of the processed work W may be measured with a caliper or the like, and the dimensional error may be input from the operation panel 22 as an actually measured value of the amount of thermal displacement. in this case,
The process of reading the operation panel 22 and its input corresponds to an actual measurement value detection unit. However, if the configuration using the detector 49 of the above embodiment is adopted, the accurate actual measurement value of the thermal displacement of the machine tool 10 can be automatically and easily detected by a simple configuration in which the detector 49 is additionally provided. can do. Therefore,
While simplifying the configuration of the device to reduce manufacturing costs,
The above parameters can be calculated more accurately and easily.

Further, in the above-described embodiment, the program for executing the processing of FIG.
Although these programs are stored in the ROM of the PU 72, it goes without saying that these programs may be stored in a storage medium such as a floppy disk or a CD-ROM. in this case,
Any control means such as a general computer can execute the above processing.

[Brief description of the drawings]

FIG. 1 is a schematic diagram illustrating a configuration of a detector of a machine tool according to an embodiment.

FIG. 2 is a block diagram illustrating a configuration of a control system of the machine tool according to the first embodiment.

FIG. 3 is an explanatory diagram illustrating a configuration of a pitch error correction table of the machine tool.

FIG. 4 is a flowchart illustrating a thermal displacement amount calculation process executed by a CPU of the machine tool.

FIG. 5 is an explanatory diagram illustrating a configuration of a map used for calculating a maximum displacement amount.

FIG. 6 is an explanatory diagram exemplifying a temporal change of a thermal displacement amount corresponding to a maximum displacement amount.

FIG. 7 is an explanatory diagram illustrating a process of calculating a total thermal displacement amount from a thermal displacement amount.

FIG. 8 is a flowchart illustrating a thermal displacement amount parameter calculation process executed by the CPU.

FIG. 9 is an explanatory diagram exemplifying a change in an actually measured value detected in the processing;

FIG. 10 is an explanatory diagram illustrating a configuration of another map used for calculating a maximum displacement amount.

FIG. 11 is a block diagram illustrating a configuration of a control system of a machine tool according to a second embodiment.

FIG. 12 is an explanatory diagram illustrating a configuration of a machine tool according to an embodiment and a conventional example.

FIG. 13 is an explanatory diagram illustrating a configuration of a machine tool according to an embodiment and a conventional example.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 ... Machine tool 14 ... Table 16 ... ATC magazine 20 ... Main body 28 ... Spindle 30 ... Spindle motor 36 ... Ball screw mechanism 38 ... Z-axis motor 49 ... Detector 60 ... Z-axis control system 70 ... Microcomputer part 72, 82 ... CPU 7
4, 84 RAM 76, 86 Clock 80 PC

Claims (8)

[Claims] 1. A processing means for processing a workpiece, a driving means for changing a relative position between the processing means and the workpiece, and a driving means for controlling the driving means based on a given processing program. A driving state detection means for detecting a driving state of the machine tool, the driving state detecting means detecting the driving state of the machine tool, and a predetermined correspondence relationship based on the driving state detected by the driving state detection means. Calculating a thermal displacement amount of the machine, and providing the thermal displacement amount as a correction value to be considered when the drive control unit controls the drive unit; A thermal displacement parameter calculation device for a machine tool, which is used for an apparatus and calculates a parameter defining the correspondence relationship referred to when the thermal displacement amount is calculated by the displacement amount calculating means, Program storage means for storing a plurality of defined machining programs; program execution means for causing the drive control means to sequentially execute control based on the respective machining programs; and the drive control means executing control based on the respective machining programs. When the actual measurement value of the thermal displacement of the machine tool is detected, the driving state of the machine tool corresponding to the machining program, and the actual measurement of the thermal displacement detected by the actual value detection means A parameter calculating means for calculating the parameter based on the value and a thermal displacement parameter calculating device for a machine tool. 2. The program execution means causes the drive control means to repeatedly execute control based on the same machining program until the heat generation amount and the heat release amount are balanced and the heat displacement amount becomes a saturated heat displacement amount. After the machine tool is stopped and the thermal displacement of the machine tool is eliminated, the control based on another machining program is similarly executed, and the actually measured value detection unit determines at least the saturated thermal displacement amount corresponding to each of the machining programs. An actual measurement value is detected, and the parameter calculating means drives the machine tool based on a driving state of the machine tool corresponding to each machining program and an actual measurement value of a saturated thermal displacement amount corresponding to each machining program. 2. The apparatus for calculating a thermal displacement parameter of a machine tool according to claim 1, wherein a parameter defining a correspondence between the state and the saturated thermal displacement is calculated. 3. A driving state of the machine tool referred to by the parameter calculating means when calculating the parameter, and
The driving state of the machine tool, in which the correspondence relationship with the saturated thermal displacement amount is defined by the parameter, is an average moving distance in which the driving means moves the processing means or the workpiece per unit time. 3. The apparatus for calculating a thermal displacement parameter of a machine tool according to claim 2, wherein: 4. The actually measured value detecting means detects an actually measured value of the thermal displacement amount of the machine tool at predetermined time intervals until reaching the saturated thermal displacement amount, and the parameter calculating means adds the parameter to the parameter. ,
Based on the driving time of the machine tool and the actually measured value of the thermal displacement amount detected at each point in time, a parameter that defines the correspondence between the driving time of the machine tool and the thermal displacement amount is calculated. The apparatus for calculating a parameter of a thermal displacement of a machine tool according to claim 2 or 3. 5. The actually measured value detecting means detects an actually measured value of the thermal displacement amount of the machine tool at predetermined time intervals after the machine tool is stopped until the thermal displacement disappears. , In addition to the above parameters,
Based on the stop time of the machine tool and the actually measured value of the thermal displacement detected at each point in time, calculating a parameter that defines the correspondence between the stop time of the machine tool and the remaining thermal displacement. The thermal displacement parameter calculation device for a machine tool according to any one of claims 2 to 4. 6. A processing means detecting means for detecting the processing means when the processing means relatively moves to a predetermined position with respect to the workpiece, the actual measurement value detecting means controlling the driving means, And a processing means moving means for relatively moving the processing means to a position detected by the processing means detection means. The processing means moving means relatively moves the processing means to a position detected by the processing means detection means. The driving amount of the driving means required to perform the driving is compared with the driving amount required when no thermal displacement occurs in the machine tool, and the actual measurement value is detected based on the comparison result. The apparatus for calculating a thermal displacement parameter of a machine tool according to any one of claims 1 to 5, wherein: 7. A machine tool comprising the machine tool thermal displacement parameter calculating device according to claim 1. Description: 8. A processing means for processing a workpiece, a driving means for changing a relative position between the processing means and the workpiece, and a driving means for controlling the driving means based on a given processing program. A driving state detecting means for detecting a driving state of the machine tool; a driving state detecting means for detecting a driving state of the machine tool; Calculating the thermal displacement of the machine, and providing the drive control as a correction value to be considered when controlling the drive by the drive control; and A storage medium that is used for an apparatus and stores a computer program for calculating a parameter that defines the correspondence that is referred to when calculating the thermal displacement amount by the displacement amount calculating means. A machining program storage unit that stores a plurality of preset machining programs; a program execution process for causing the drive control unit to sequentially execute control based on each of the machining programs; An actual measurement value detection process for detecting an actual measurement value of the thermal displacement amount of the machine tool when the control is executed; and a driving state of the machine tool corresponding to the machining program and the thermal displacement detected by the actual measurement value detection process. A storage medium, comprising: a processing storage unit storing a computer program for executing a parameter calculation process for calculating the parameter based on an actual measured value of an amount.