JP2020059072A - Machine tool and processing method - Google Patents

Abstract

To provide a machine tool and a processing method that can process a work-piece with high accuracy by adjusting correction values corresponding to displacement caused by thermal deformation for each machine tool, with respect to a distance between a spindle shaft center and a blade edge.SOLUTION: A machine tool 100 includes: an operation executing part 23 that executes the tool execute continuous operation for adjustment for intermittently processing a plurality of work-pieces with idle machining for driving a spindle 10 and a blade base 5 without cutting the work-pieces W intervened in the operation, using a prescribed correction method; and a coefficient adjustment part 24 that adjusts coefficients K1-K5 used for estimating a prescribed thermal displacement amount in the prescribed correction method to reduce a displacement amount on the basis of dimensions of the work-pieces W already processed during the continuous operation for adjustment and the displaced amount from a design value.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a machine tool and a machining method.

  A lathe, which is one of machine tools, includes a spindle that holds and rotates a work, and a tool rest that holds a tool for cutting the work. In such a lathe, the main shaft and the tool rest are relatively moved, and the work is performed while the work and the tool are relatively moved. When cutting a work piece, the spindle, the tool rest, and the bed that supports them are thermally deformed due to the cutting heat generated when cutting the work piece, or the heat generated in each part during operation. The distance in the cutting direction between and varies. Because the position of the blade edge of the blade with respect to the workpiece deviates from the assumed value (set value) due to this distance variation, the distance variation due to thermal deformation is appropriately corrected in the cutting direction between the spindle axis and the blade edge. The method is used (for example, see Patent Document 1).

JP, 2008-079526, A

  In order to process a work with high accuracy, when the distance between the spindle axis and the cutting edge fluctuates due to heat, it is necessary to accurately correct the amount of movement due to thermal deformation. Therefore, it is conceivable that a common correction formula for correcting the movement amount due to thermal deformation is prepared in advance and the correction formula is applied to a plurality of machine tools. In this case, since the amount of movement due to thermal deformation differs for each machine tool, applying a common correction formula may not allow the work to be machined with high accuracy.

  The present invention provides a machine tool and a machining method capable of machining a workpiece with high accuracy by adjusting a correction value according to a displacement due to thermal deformation for each machine tool with respect to a distance between a spindle axis and a cutting edge. The purpose is to provide.

  A machine tool according to an aspect of the present invention includes a headstock that rotatably supports a spindle having a chuck for gripping a workpiece, a tool rest to which a tool is attached, a headstock and a tool rest in a radial direction of the spindle. A bed that is relatively movable, a temperature measuring instrument that measures the temperature of a tool rest, a headstock, or their vicinity, and a spindle that measures the spindle axial position in the spindle radial direction with respect to the first reference position in the bed. Based on the side position measuring device, the tool side position measuring device that measures the third reference position of the tool rest in the spindle radial direction with respect to the second reference position in the bed, and the spindle axis center position measured by the spindle side position measuring device The headstock thermal displacement amount which is the thermal displacement amount of the headstock is calculated, and the tool rest thermal displacement amount which is the heat displacement amount of the tool rest is calculated based on the third reference position measured by the tool side position measuring device, Measured with a temperature measuring device The specified thermal displacement from the workpiece to the machining tip of the tool is estimated based on the measured temperature, and the headstock thermal displacement, the toolboard thermal displacement, and the predetermined thermal displacement are used as the items in the specified correction formula. Using a calculation unit that calculates the amount of relative movement between the tool and the turret and a predetermined correction formula, intermittently drive multiple workpieces with empty machining that drives the spindle, headstock, and turret without cutting the workpiece. Based on the amount of displacement between the operation execution unit that executes continuous adjustment operation for machining, the dimension of the workpiece after machining during the adjustment continuous operation, and the design value, a predetermined correction formula to reduce this displacement amount And a coefficient adjusting unit that adjusts the coefficient used for estimating the predetermined thermal displacement amount of.

  Further, the temperature measuring device includes a first temperature measuring device that measures the temperature of the tool rest or the vicinity thereof, and a second temperature measuring device that measures one or more temperatures of the headstock and / or its vicinity, and calculates the temperature. The part is a predetermined thermal displacement amount, based on the first temperature measured by the first temperature measuring device, the thermal displacement amount of the blade from the third reference position to the machining tip of the blade, and the second temperature measurement. From the second temperature measured by the measuring instrument to the reading standard provided in the spindle side position measuring device, that is, the amount of thermal displacement of the spindle axis, which is the amount of thermal displacement of the spindle axis, and the first temperature measured by the first temperature measuring instrument to the third reference. And the mounting position thermal displacement amount, which is the thermal displacement amount of the tool mounting position of the tool post with respect to the position, and the coefficient adjusting unit estimates the spindle shaft center thermal displacement amount and the mounting position thermal displacement amount in a predetermined correction formula. You may adjust each coefficient used for.

  Further, the temperature measuring device includes a third temperature measuring device that measures a temperature corresponding to an outside air temperature around the tool rest and the headstock, and the arithmetic unit measures the third temperature measuring device as a predetermined thermal displacement amount. The outside air factor thermal displacement amount, which is the amount of thermal displacement between the spindle axis and the machining tip of the cutting tool, is estimated from the third temperature, and the coefficient adjusting unit uses the coefficient used for estimating the outside air factor thermal displacement amount in the predetermined correction formula. You may adjust. Further, the coefficient adjusting unit may include an input unit capable of inputting the dimension of the work after machining during the continuous operation for adjustment, and the coefficient adjusting unit may adjust the coefficient based on the dimension of the work input to the input unit. Further, the operation executing unit may set the number of workpieces to be machined within a range in which the machining tip of the cutting tool is not worn or almost not worn.

  A machining method according to an aspect of the present invention includes a headstock that rotatably supports a spindle having a chuck for gripping a workpiece, a tool rest to which a tool is attached, a headstock and a tool rest in a radial direction of the spindle. A bed that is relatively movable, a temperature measuring instrument that measures the temperature of a tool rest, a headstock, or their vicinity, and a spindle that measures the spindle axial position in the spindle radial direction with respect to the first reference position in the bed. A machining method using a machine tool, comprising: a side position measuring device; and a tool side position measuring device that measures a third reference position of a tool rest in a radial direction of the spindle with respect to a second reference position on a bed. Calculating the headstock thermal displacement amount, which is the thermal displacement amount of the headstock, based on the spindle shaft center position measured by the position measuring device, and based on the third reference position measured by the toolside position measuring device. Heat of the table Calculating the tool post thermal displacement amount, which is a unit, and estimating the predetermined thermal displacement amount from the workpiece to the machining tip of the tool based on the temperature measured by the temperature measuring device, and the headstock thermal displacement amount, Calculating the relative movement amount of the headstock and turret by a predetermined correction formula that has the tool rest thermal displacement amount and the predetermined thermal displacement amount as items, and the main spindle without cutting the workpiece while using the predetermined correction formula. , Performing continuous operation for adjustment that intermittently processes multiple workpieces with empty machining that drives the headstock and turret, and the dimensions of the workpiece after machining during the continuous operation for adjustment, and design values And adjusting the coefficient used to estimate the predetermined thermal displacement amount of the predetermined correction formula based on the displacement amount of the above.

  According to the machine tool and the machining method described above, the adjustment for intermittently machining a plurality of works by using the predetermined correction formula and sandwiching the blank machining for driving the spindle, the headstock, and the tool rest without cutting the work For the estimation of the predetermined thermal displacement amount of the predetermined correction formula so as to reduce this displacement amount based on the displacement amount of the workpiece after machining and the design value during the adjustment continuous operation. Since the used coefficient is adjusted, the correction value for the distance between the spindle axis and the cutting edge can be adjusted for each machine tool according to the displacement due to thermal deformation, and the work can be machined with high accuracy.

  In addition, the temperature measuring device includes a first temperature measuring device and a second temperature measuring device, and the computing unit, as the predetermined thermal displacement amount, the blade thermal displacement amount, the spindle axial core thermal displacement amount, and the mounting position. In the configuration in which the thermal displacement amount is estimated and the coefficient adjusting unit adjusts the respective coefficients used for estimating the spindle shaft center thermal displacement amount and the mounting position thermal displacement amount in the predetermined correction formula, the displacement due to thermal deformation Can be accurately corrected.

  In addition, the temperature measuring device includes a third temperature measuring device, and the calculation unit, as the predetermined thermal displacement amount, the thermal displacement amount between the spindle axis and the machining tip of the blade from the third temperature measured by the third temperature measuring device. The coefficient adjustment unit adjusts the correction value including the thermal displacement amount due to the outside air in the configuration that adjusts the coefficient used to estimate the external air factor thermal displacement amount in the predetermined correction formula. Therefore, the displacement due to thermal deformation can be corrected more accurately. Further, in the configuration in which the coefficient adjusting section adjusts the coefficient based on the dimension of the work input to the input section, the input section capable of inputting the dimension of the work after machining in the continuous operation for adjustment is provided. The predetermined correction formula can be easily adjusted only by inputting the size of the work through the input unit. Further, in the configuration in which the operation executing unit sets the number of workpieces to be machined within the range where the machining tip of the blade does not wear or almost does not wear, the influence of the variation in the dimension of the workpiece due to the wear of the machining tip of the blade is suppressed. Therefore, the coefficient can be adjusted more accurately.

It is a figure which shows an example of the machine tool which concerns on embodiment of this invention. It is a perspective view showing an example of a main part. It is a figure which shows an example at the time of seeing a main-body part from the + Y side. It is a figure which shows an example at the time of seeing a main-body part from the + Z side. It is a graph which shows an example of the driving cycle of continuous operation for adjustment. 7 is a graph showing a predetermined thermal displacement amount before and after the coefficient adjustment by the coefficient adjusting unit. It is a figure which shows an example of the display screen displayed on a display part. 7 is a flowchart showing an example of processing for calculating a correction value. It is a flow chart which shows an example of continuous operation for adjustment. (A) is a graph showing a predetermined thermal displacement amount before and after coefficient adjustment for another machine tool, and (B) is a graph showing a predetermined thermal displacement amount before and after coefficient adjustment for another machine tool. (A) is a graph showing a predetermined thermal displacement amount before and after coefficient adjustment for another machine tool, and (B) is a graph showing a predetermined thermal displacement amount before and after coefficient adjustment for another machine tool.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the present invention is not limited to the modes described below. Further, in the drawings, in order to describe the embodiment, a part of the drawing is enlarged or emphasized, and the scale is appropriately changed. In each of the following drawings, the directions in the drawings will be described using the XYZ coordinate system. In the XYZ coordinate system in each of the following embodiments, the rotation axis direction of the main axis is the Z direction, the plane parallel to the horizontal plane is the YZ plane, and the direction orthogonal to the Z direction is the Y direction. The direction perpendicular to the YZ plane is the X direction, and this X direction is the direction that defines the cutting amount for the work. In each of the X direction, the Y direction, and the Z direction, the direction indicated by the arrow in the drawing is the + direction, and the opposite direction is the − direction. Further, in each of the following embodiments, the direction around the Y axis is represented as the θY direction, and the direction around the Z axis is represented as the θZ direction. Regarding the θY direction and the θZ direction, the clockwise direction when viewed from the + Y side and the + Z side is the + direction, and the counterclockwise direction is the − direction.

  A machine tool 100 according to the embodiment will be described with reference to the drawings. FIG. 1 is a diagram illustrating an example of a machine tool 100 according to the embodiment. 2 is a perspective view showing an example of the main body 1. FIG. 3 is a diagram showing an example of the main body 1 viewed from the + Y side. FIG. 4 is a diagram showing an example of the main body 1 viewed from the + Z side. The machine tool 100 shown in FIGS. 1 to 4 is a lathe. The machine tool 100 includes a main body 1 and a control device 2.

  As shown in FIGS. 1 to 4, the main body unit 1 includes a bed 3, a headstock 4, a tool rest 5, a moving device 6, and a measuring device 7. The bed 3 is, for example, a fixed base placed on the floor or the like. A cover C that surrounds the headstock 4 and the tool rest 5 is provided on the bed 3. The headstock 4 is supported by the bed 3 via a moving device 6. The headstock 4 can be moved in the X direction and the Z direction by a moving device 6. The headstock 4 has a main spindle 10. The main shaft 10 is supported by bearings (not shown) so as to be rotatable in the θZ direction around a main shaft axis AX1 parallel to the Z direction. A chuck drive unit 11 is provided at the + Z side end of the main shaft 10.

  The chuck drive unit 11 has a plurality of grip claws (chuck) 11 a for holding the work W. Each of the plurality of grip claws 11 a is movable in the radial direction of the spindle 10. The chuck drive unit 11 moves the plurality of grip claws 11 a in the radial direction of the main shaft 10 to hold the work W. When the work W is held by the gripping claws 11a, the rotation center of the work W coincides with the spindle axis AX1. A plurality of grip claws 11a are arranged at equal intervals around the rotation axis of the main shaft 10. As the number and shape of the grip claws 11a, any configuration capable of holding the work W is used.

  The tool rest 5 is fixed to the bed 3. The turret 5 includes a turret 50. The turret 50 is supported by the tool rest 5 in a state of being rotatable in the θX direction around an axis AX2 parallel to the X direction. The turret 50 holds the blade T in a replaceable manner. As the blade T, a rotary tool such as a drill or an end mill may be used as well as a cutting tool for cutting the work W. The blade T is held by the turret 50 via the holder 51.

  A cooling device 30 is arranged below the bed 3. The cooling device 30 discharges a coolant to the processed portion of the work W to cool it. The cooling device 30 includes a coolant supply source 31 and a pipe 32. The coolant supply source 31 stores the temperature-controlled coolant. The coolant supply source 31 causes the coolant to flow through the pipe 32 by a drive source 31a such as a pump. The pipe 32 is routed along the bed 3 and inserted into the tool rest 5 from the −Z side surface of the tool rest 5. The pipe 32 is arranged so as to pass through the turret 50 and the holder 51, and the downstream end of the coolant in the flow direction is directed to the processed portion of the work W.

  The moving device 6 includes an X-direction guide 61, a feed base 62, and a Z-direction guide 63. The two X-direction guides 61 are arranged on the bed 3 in parallel along the X-direction. The X-direction guide 61 guides the feed base 62 in the X-direction. The feed table 62 is formed in a rectangular plate shape or a trapezoid shape, and is arranged on the X-direction guide 61. In this specification, a rectangle means a rectangle including a square.

  The feed table 62 moves in the X direction by the driving of the X direction drive unit 64. The X-direction drive unit 64 is, for example, a mechanism that uses a rotational driving force of an electric motor or the like to convert it into a linear motion by a ball screw mechanism, a mechanism that uses a rack and a pinion gear, a hydraulic or pneumatic cylinder device, or the like. To be The two Z-direction guides 63 are arranged on the feed base 62 in parallel along the Z-direction. The Z direction guide 63 guides the headstock 4 in the Z direction. The headstock 4 moves in the Z direction by the drive of the Z direction drive unit 65. The Z-direction drive unit 65 has the same configuration as the X-direction drive unit 64, such as an electric motor.

  The measuring device 7 includes a reference frame 70, a spindle side position measuring device 71, and a blade side position measuring device 72. Further, the measuring device 7 serves as a temperature measuring device such as a first temperature measuring device 73, a second temperature measuring device 74, a third temperature measuring device 79, a fourth temperature measuring device 75, and a fifth temperature measuring device 76. And. The reference frame 70 has a pillar portion 77 and a horizontal portion 78. The reference frame 70 is formed using a material having a coefficient of thermal expansion lower than that of the bed 3. Examples of such a material include alloy materials such as Invar material, ceramics, and the like. The column 77 is arranged in a state of standing upright from the bed 3 along the Y direction. The column part 77 is fixed to the bed 3 by a fixing member (not shown) or the like.

  The horizontal portion 78 is arranged such that the base end side is connected to the upper end of the column portion 77 and extends linearly in the + Z direction. The horizontal portion 78 is supported by the column portion 77 in a so-called cantilever shape. The horizontal portion 78 is supported by the reinforcing portion 78a (see FIG. 2). The horizontal portion 78 is arranged at the height of the axis AX2 of the rotating shaft of the turret 50. The + Z side end of the horizontal portion 78 is arranged at the + X side position of the tool rest 5 (that is, at the position opposite to the turret 50). A through hole for inserting a second scale 72a and a second reading device 72b, which will be described later, is formed at the + Z side end of the horizontal portion 78. The through hole is provided so as to penetrate the horizontal portion 78 in the X direction.

  The spindle side position measuring device 71 detects the displacement of the spindle axis center AX1 in the X direction. The spindle side position measuring device 71 has a first scale 71a and a first reading device 71b. The first scale 71a is, for example, a rod-shaped member having a circular cross section, an elliptical cross section, or a polygonal cross section. The first scale 71a is connected to the pillar portion 77 and is linearly arranged along the X direction. The first scale 71a is supported by the pillar portion 77 in a so-called cantilever shape. The position of the first scale 71a in the Y direction is arranged at the height position of the feed table 62. The end of the first scale 71a in the −X direction is arranged at the + Z side of the feed table 62.

  The first scale 71a has scales M1 formed side by side in the X direction. The scale M1 can be read optically or magnetically. The scale M1 may have a configuration directly formed on the first scale 71a, or may have a configuration in which a member having a scale is attached to the first scale 71a. In the present embodiment, the scale M1 has a configuration in which, for example, magnetic portions and nonmagnetic portions are alternately arranged in the X direction of the first scale 71a. The scale M1 is formed in a region including a range in which the spindle 10 moves in the X direction (a movement range of the spindle axis AX1 in the X direction). In the first scale 71a, the portion supported by the column 77 is the first reference position P1. That is, the spindle side position measuring device 71 measures the position of the spindle axis center AX1 in the radial direction of the spindle 10 with respect to the first reference position P1 in the bed 3.

  The first reading device 71b is fixed to the end surface 62a on the + Z side of the feed table 62, and has a reading reference on a plane perpendicular to the radial direction of the spindle 10 that passes through the spindle axis AX1. The reading reference is a plane shape that passes through the main axis AX1 and is parallel to the YZ plane. As the first reading device 71b, for example, a magnetic head that detects a magnetic portion and a non-magnetic portion is used. When the headstock 4 and the feed base 62 are thermally deformed, the first reading device 71b is displaced along with the deformation of the headstock 4 and the feed base 62. Therefore, the first reading device 71b can detect the displacement when it is displaced in the X direction with respect to the scale M1 (magnetic portion and nonmagnetic portion) formed on the first scale 71a. The first reading device 71b transmits the displacement in the X direction with respect to the scale M1 to the control device 2 as an electric signal.

  The blade side position measuring device 72 measures the displacement in the X direction of the end surface 50a of the turret 50 on the −X side (the blade T side or the work W side). The blade-side position measuring device 72 has a second scale 72a and a second reading device 72b. Similar to the first scale 71a, the second scale 72a is, for example, a rod-shaped member having a circular cross section, an elliptical cross section, or a polygonal cross section, and is linearly arranged along the X direction. The second scale 72a is disposed so as to penetrate the tool rest 5 and the turret 50 in the X direction with the central axis thereof aligned with the rotation axis AX2 of the turret 50, and is provided integrally with the tool rest 5 and the turret 50. To be The second scale 72a is supported on the −X side end surface 50a of the turret 50 in a so-called cantilever manner. When the tool rest 5 is thermally deformed, the second scale 72a is displaced along with the heat deformation of the tool rest 5.

  The second scale 72a is arranged such that the end portion on the + X side penetrates the horizontal portion 78 in the X direction and projects toward the + X side. The 2nd scale 72a has the scale M2 arrange | positioned along with the X direction similarly to the 1st scale 71a. The scale M2 can be read optically or magnetically. The scale M2 is arranged in a region of the second scale 72a to be inserted inside the horizontal portion 78. The position of the horizontal portion 78 through which the second scale 72a penetrates becomes the second reference position P2.

  The −X side end surface 72c of the second scale 72a is arranged so as to match the −X side end surface 50a of the turret 50. The position of the end surface 72c in the X direction coincides with the end surface 50a of the turret 50. The end surface 50a is the third reference position P3 of the tool rest 5. Therefore, the end surface 72c of the second scale 72a is arranged at the third reference position P3. That is, the blade-side position measuring device 72 measures the position of the third reference position P3 with respect to the second reference position P2 of the bed 3. The first reference position P1 and the second reference position P2 are positions where the thermal displacement amounts are equal to each other in the radial direction of the main axis, and are coincident with each other. Further, since the first reference position P1 and the second reference position P2 are respectively set to the Invar material or the like having a low coefficient of thermal expansion, it is possible to prevent the both from moving relatively. However, the first reference position P1 and the second reference position P2 may be arranged in different reference frames or the like.

  The second reading device 72b is fixed to the second reference position P2 of the horizontal portion 78. The second reference position P2 is a position inside the horizontal portion 78 that overlaps the axis AX2 of the turret 50. As the second reading device 72b, for example, a magnetic head that detects a magnetic portion and a non-magnetic portion is used. The second reading device 72b can detect displacement when the scale M2 (magnetic portion and non-magnetic portion) is displaced in the X direction. When the scale M2 is displaced in the X direction, the second reading device 72b transmits this displacement to the control device 2 as an electric signal. As described above, in the blade-side position measuring device 72 of the present embodiment, the second reading device 72b is arranged at the fixed position and the second scale 72a is displaced, but the present invention is not limited to this. For example, the second scale 72a may be fixed to the horizontal portion 78, and the second reading device 72b may be arranged on the end surface 50a of the turret 50.

  The first temperature measuring device 73 is arranged, for example, on the −Z side end surface of the tool rest 5. The first temperature measuring device 73 measures the first temperature t1 of the tool rest 5 or the vicinity thereof. The first temperature measuring device 73 measures the temperature of the pipe 32 to measure the temperature of the coolant flowing through the pipe 32. Since the coolant is discharged toward the blade T during cutting, the temperature of the pipe 32 through which the coolant flows is substantially equal to the temperature of the blade T and its surroundings during cutting. Therefore, by measuring the temperature of the coolant in the pipe 32, the first temperature t1 of the tool rest 5 at the time of cutting or the vicinity thereof can be measured.

  The second temperature measuring device 74 measures one or more second temperatures which are temperatures of the headstock 4 (or the spindle 10) and / or its vicinity. The second temperature measuring device 74 may have any attachment position as long as it can measure the second temperature t2 of the headstock 4, and may be attached, for example, in the vicinity of the main spindle 10, or the headstock 4 or the main spindle 10. May be placed inside. Further, the second temperature measuring device 74 may not be arranged. In the present embodiment, the second temperature measuring device 74 is attached to the + X side surface of the headstock 4. The second temperature t2 detected by the second temperature measuring device 74 is, for example, the same or almost the same temperature as the area TEM1 (area surrounded by a broken line) near the main shaft 10 shown in FIG.

  The third temperature measuring device 79 is provided inside the cover C. The third temperature measuring device 79 measures the third temperature t3 inside the cover C. In the present embodiment, the third temperature t3 inside the cover C corresponds to the outside air temperature around the tool rest 5 and the headstock 4. Therefore, the third temperature measuring device 79 can measure the temperature corresponding to the outside air temperature around the tool rest 5 and the headstock 4 by measuring the third temperature t3. The third temperature measuring device 79 is not limited to the inside of the cover C, and may be arranged, for example, outside the cover C, or provided apart from the outside of the cover C (away from the main body 1). May be.

  The fourth temperature measuring device 75 measures the fourth temperature t4 which is the temperature of the feed table 62. The fourth temperature measuring device 75 is attached to the surface of the feed base 62, for example, and can measure the temperature of the feed base 62. The fourth temperature measuring device 75 may be arranged inside the feed base 62. In the present embodiment, the fourth temperature measuring instrument 75 is attached to the + Y-side surface of the corner of the feed base 62 on the + X side and the −Z side. The fourth temperature t4 detected by the fourth temperature measuring device 75 is, for example, the same or almost the same temperature as the −X side region TEM2 (region surrounded by a broken line) of the feed table 62 shown in FIG. .

  The fifth temperature measuring device 76 is arranged on the + Y side surface of the bed 3 and in the −Z side region of the tool rest 5. The fifth temperature measuring device 76 measures the temperature (fifth temperature) t5 of the region of the bed 3 on the −Z side of the tool rest 5. The fifth temperature t5 detected by the fifth temperature measuring device 76 is, for example, the same or substantially the same as the temperature of the region TEM3 on the + Z side end surface of the tool rest 5 shown in FIG. Further, one or both of the fourth temperature measuring device 75 and the fifth temperature measuring device 76 may not be arranged.

  As shown in FIG. 1, the control device 2 is, for example, a computer and has a numerical control function and a programmable controller. The control device 2 includes a movement control unit 21, a calculation unit 22, an operation execution unit 23, a coefficient adjustment unit 24, a storage unit 25, an input unit 26, and a display unit 27. The movement control unit 21 controls the X-direction driving unit 64 and the Z-direction driving unit 65 of the moving device 6 to relatively move the work W and the blade T in the X and Z directions. When controlling the relative movement in the X direction between the work W and the blade T, the movement control unit 21 controls the distance L in the X direction between the spindle axis AX1 of the spindle 10 and the cutting edge Ta of the blade T.

  This distance L is determined by the position of the headstock 4 in the X direction and the mounting dimensions in the X direction of the turret 50, the holder 51 and the tool T which are mounted on the tool rest 5. The distance L may be measured, for example, by abutting (or actually cutting) the blade T on a test piece held on the main shaft 10. Further, the control device 2 corrects the processing data (for example, the coordinate value) of the work W based on each thermal displacement amount described later, and the movement control unit 21 controls the X-direction drive unit 64 and The Z direction drive unit 65 is controlled.

  The calculation unit 22 performs various calculations based on, for example, the programs and data stored in the storage unit 25. The calculation unit 22 calculates the headstock thermal displacement amount ΔS based on the displacement (position) in the X direction of the spindle axis AX1 measured by the spindle side position measuring device 71. The headstock thermal displacement amount ΔS is a thermal displacement amount of the headstock 4 caused by heat. Further, the calculation unit 22 calculates the tool post thermal displacement amount ΔT based on the displacement (position) in the X direction of the third reference position P3 measured by the tool side position measurement device 72. The tool post thermal displacement amount ΔT is a thermal displacement amount of the tool post 5 caused by heat.

  The calculation unit 22 estimates the blade thermal displacement amount ΔH based on the first temperature t1 measured by the first temperature measuring device 73. The blade thermal displacement amount ΔH is the thermal displacement amount in the X direction of the portion (the holder 51 and the blade T) from the third reference position P3 to the blade tip Ta of the blade T. There is a predetermined correlation between the first temperature t1 and the blade thermal displacement amount ΔH. The correlation between the first temperature t1 and the thermal displacement amount ΔH of the blade is obtained in advance by experiments, simulations, or the like. This correlation is stored in the storage unit 25, for example, as function data of the blade thermal displacement amount ΔH having the value of the first temperature t1 as a variable. In this case, the calculation unit 22 uses the function data stored in the storage unit 25 to calculate the blade thermal displacement amount ΔH corresponding to the value of the first temperature t1.

  Further, the calculation unit 22 may estimate the spindle shaft thermal displacement amount Δθs based on the temperature (second temperature) t2 of the spindle 10 measured by the second temperature measuring device 74. As shown in FIG. 4, the spindle shaft center thermal displacement amount Δθs is the thermal displacement amount of the spindle shaft center AX1 with respect to the reading reference. For example, the thermal displacement amount Δθs of the spindle shaft center is a value obtained by extracting a component in the X direction from the thermal displacement amounts around the Z axis of the headstock 4 centered around the first reading device 71b or the first reading device 71b. Is. The thermal displacement amount Δθs of the spindle shaft center includes, for example, the thermal displacement amount of the spindle shaft center AX1 caused by the thermal displacement of the gap formed between the headstock 4 and the Z-direction guide 63.

  There is a predetermined correlation between the second temperature t2 and the spindle shaft center thermal displacement amount Δθs. The main axis thermal displacement amount Δθs increases in absolute value on the + (plus) side as the temperature difference between the second temperature t2 and the fourth temperature t4 increases. If there is a correlation between the second temperature and the fourth temperature t4, the temperature of the fourth temperature t4 is calculated from the value of the second temperature t2, and the temperature difference is calculated based on the calculation result. Good. Such a correlation between the temperature difference between the second temperature t2 and the fourth temperature t4 and the spindle shaft center thermal displacement amount Δθs is obtained in advance by experiments or simulations. This correlation is stored in the storage unit 25, for example, as function data of the thermal displacement amount Δθs of the spindle shaft center with the value of the temperature difference as a variable. In this case, the calculation unit 22 uses the function data stored in the storage unit 25 to calculate the spindle shaft center thermal displacement amount Δθs corresponding to the value of the second temperature t2.

  In the control device 2, the movement control unit 21 and the calculation unit 22 may be realized by software. Further, the control device 2 may be configured by the movement control unit 21 and the calculation unit 22 by different control devices. Further, as the storage unit 25, for example, a hard disk built in the control device 2, a portable CD-ROM, a USB memory, or the like may be used.

  Further, the calculation unit 22 estimates the mounting position thermal displacement amount Δθt from the temperature (first temperature) t1 of the pipe 32 measured by the first temperature measuring device 73. The mounting position thermal displacement amount Δθt is the thermal displacement amount of the blade mounting position of the turret 50 with respect to the −X side end surface 72c of the second scale 72a (or the rotation center of the turret 50), as shown in FIG. The attachment position thermal displacement amount Δθt is a value obtained by extracting the component in the X direction from the thermal displacement amount around the X axis of the tool rest 5 centered on the end face 72c.

  There is a predetermined correlation between the first temperature t1 and the mounting position thermal displacement amount Δθt. The attachment position thermal displacement amount Δθt increases in absolute value on the − (minus) side as the temperature difference between the first temperature t1 and the fifth temperature t5 increases. Such a correlation between the temperature difference between the first temperature t1 and the fifth temperature t5 and the mounting position thermal displacement amount Δθt is obtained in advance by experiments or simulations. This correlation is stored in the storage unit 25 as, for example, function data of the attachment position thermal displacement amount Δθt having a variable of the temperature difference between the first temperature t1 and the fifth temperature t5. In this case, the calculation unit 22 uses the function data stored in the storage unit 25 to calculate the mounting position thermal displacement amount Δθt corresponding to the temperature difference between the first temperature t1 and the fifth temperature t5.

  Further, the calculation unit 22 calculates the outside air factor thermal displacement amount ΔG which is the thermal displacement amount between the spindle axis AX1 and the blade tip (machining tip) blade tip Ta of the tool T from the third temperature t3 measured by the third temperature measuring device 79. presume. The outside air factor thermal displacement amount ΔG is a thermal displacement amount due to the outside air temperature among the thermal displacement amounts of the blade mounting position of the turret 50 with respect to the −X side end surface 72c (or the rotation center of the turret 50) of the second scale 72a. is there. The outside air factor thermal displacement amount ΔG is a value obtained by extracting a component in the X direction of the thermal displacement amount around the X axis of the tool rest 5 centered on the end surface 72c.

  There is a predetermined correlation between the third temperature t3 and the outside air factor thermal displacement amount ΔG. The correlation between the third temperature t3 and the outside air factor thermal displacement amount ΔG is obtained in advance by experiments or simulations. This correlation is stored in the storage unit 25 as, for example, function data of the outside air factor thermal displacement amount ΔG having the value of the third temperature t3 as a variable. In this case, the calculation unit 22 uses the function data stored in the storage unit 25 to calculate the outside air factor thermal displacement amount ΔG corresponding to the third temperature t3. Further, the third temperature measuring device 79 may not be arranged. In this case, the outside air factor thermal displacement amount ΔG based on the third temperature t3 is excluded from the predetermined correction formula described later.

  The calculation unit 22 calculates the headstock thermal displacement amount ΔS, the tool post thermal displacement amount ΔT, the tool blade thermal displacement amount ΔH, the spindle shaft center thermal displacement amount Δθs, the mounting position thermal displacement amount Δθt, and the outside air factor thermal displacement amount ΔG. The relative movement amount between the headstock 4 and the tool rest 5 can be calculated by including it in the correction value. In this case, the correction value ΔX is expressed by the following predetermined correction formula.

ΔX = ΔS + ΔT + ΔH + Δθs + Δθt + ΔG
Of these, for Δθs, Δθt, and ΔG,
Δθs = K1 · Δt2 + K2 · Δt4
Δθt = K3 · Δt1 + K4 · Δt5
ΔG = K5 · Δt3
It is represented by. It should be noted that each of Δt1 to Δt5 is the amount of change from the first temperature t1 to the fifth temperature t5 in the predetermined period. Further, each of K1 to K5 is a coefficient.

  The operation execution unit 23 causes the machine tool 100 to execute the continuous adjustment operation while using the above-described predetermined correction formula. The continuous operation for adjustment is an operation for intermittently machining a plurality of works W with empty machining that drives the spindle 10, the headstock 4 and the tool rest 5 without cutting the works W. As the empty machining that does not cut the work W, for example, a mode in which the spindle 10, the headstock 4, and the tool rest 5 are driven without the gripping claw (chuck) 11a gripping the work W, and the work W is held by the gripping claw 11a. There is a form in which the work W is not cut by the tool T (while cutting chips are not produced) while the tool W is gripped and the spindle 10, the headstock 4 and the tool rest 5 are driven. In this mode, in the mode in which the workpiece W is not cut by the blade T while the workpiece W is gripped by the grip claws 11a, the operation execution unit 23, for example, prevents the blade T from contacting the workpiece W and the headstock 4 and the blade. The drive of the headstock 4 and the tool rest 5 is controlled in a state where an offset is set with respect to the movement amount of the base 5. The operation execution unit 23 sets the number of workpieces W to be machined within a range in which the cutting edge Ta, which is the machining tip of the cutting tool T, does not wear or does not wear.

  FIG. 5 is a graph showing an example of the operation cycle of the adjustment continuous operation. The horizontal axis of FIG. 5 shows the elapsed time from the power-on of the machine tool 100, and the vertical axis shows the diameter of the work W after machining. The vertical axis of FIG. 5 indicates the dimension of the work W after processing with respect to the design value. In the example shown in FIG. 5, the operation execution unit 23 sets the number of workpieces W to be processed to, for example, 13. First, the operation execution unit 23 controls to machine the first work W when the power of the machine tool 100 is turned off and then turned on. After processing the first work W, the operation execution unit 23 controls to perform idle processing until 15 minutes have elapsed after the power was turned on, that is, until the next work W starts to be processed. To do. In the blank machining, the spindle 10 is moved in the X direction and the tool rest 5 is moved in the Z direction while rotating the spindle 10 without cutting the work W. As a form of empty machining, as described above, the rotation of the spindle 10 is performed without the gripping claw 11a gripping the work W. That is, this blank machining is an operation of machining the work W without the work W. As another form of blank machining, the work W is gripped by the grip claws 11a and the spindle 10 is rotated, but the work W is not cut by the blade T. It should be noted that which form is to be performed in blank processing is arbitrary.

  Next, the operation execution unit 23 controls to process the second work W 15 minutes after the power is turned on, and processes the third work W 30 minutes after the power is turned on. To control. That is, the processing of the second and third workpieces W is performed at intervals of 15 minutes. In addition, the operation executing unit 23 processes the second work W from the processing to the start of the processing of the third work W and the processing of the fourth work W after the processing of the third work W. Control is performed so that blank machining is performed before and after the start.

  Next, the operation execution unit 23 controls so that the fourth work W is processed after 1 hour has passed since the power was turned on. That is, the processing of the fourth work W is performed at intervals of 30 minutes with respect to the processing of the third work W. After processing the fourth work W, the operation execution unit 23 controls to perform idle processing until the start of processing of the next work W.

  Then, the operation executing unit 23 controls to process the fifth work W after 2 hours have passed since the power was turned on, and to process the sixth work W after 3 hours have passed since the power was turned on. To control. That is, the processing of the fifth and sixth workpieces W is performed at 1-hour intervals. In addition, the operation execution unit 23 controls to perform idle machining from after the machining of the fifth work W to the machining start of the sixth work W. The reason why four workpieces W are machined within one hour after the power is turned on is that the thermal displacement is large during the one hour after the power is turned on, and the history of thermal displacement is obtained in detail.

  After processing the sixth work W, the operation executing unit 23 stops the operation with the power of the machine tool 100 turned on. In this case, the machining program is stopped and the blank machining is not executed. By providing such a stop period, when the operation of the machine tool 100 is stopped (when the machining program is stopped) due to a break time in a factory or tool change, the subsequent thermal displacement data can be acquired. The versatility of the predetermined correction formula can be improved. One hour after the operation of the machine tool 100 has stopped, the operation executing unit 23 restarts the operation of the machine tool 100 and, at the same time, controls the machining of the seventh work W. The stop time is not limited to one hour, and can be set to 15 minutes or 30 minutes, for example. Moreover, the number of stops is not limited to one, and may be two or more. After processing the seventh work W, the operation execution unit 23 controls to perform idle processing until the start of processing of the next work W.

  Next, the operation execution unit 23 controls to process the eighth work W 15 minutes after the restart of the operation, and performs the processing of the ninth work W 30 minutes after the restart of the operation. Control. That is, the machining of the eighth and ninth workpieces W is performed at intervals of 15 minutes. Further, the operation executing unit 23 processes the machining of the eighth work W to the machining start of the ninth work W, and the machining of the ninth work W to the tenth work W after machining. Control is performed so that blank machining is performed before and after the start.

  Next, the operation execution unit 23 controls to process the tenth work W 1 hour after the restart of the operation. That is, the processing of the tenth work W is performed at intervals of 30 minutes with respect to the processing of the ninth work W. After processing the tenth work W, the operation execution unit 23 controls to perform idle processing until the start of processing of the next work W. The reason why four workpieces W are machined within one hour after restarting operation is that the thermal displacement is large during one hour after restarting operation and the history of thermal displacement is acquired in detail, as in the case of turning on the power. Is.

  Then, the operation execution unit 23 controls so as to process the eleventh work W after 2 hours have elapsed from the restart of operation, and performs the processing of the twelfth work W after 3 hours have elapsed after the power was turned on. Control and do. The control is performed so that the thirteenth work W is processed after 4 hours have passed since the power was turned on. That is, the processing of the eleventh, twelfth, and thirteenth workpieces W is performed at 1-hour intervals. In addition, the operation execution unit 23 processes the machining of the eleventh work W to the machining start of the twelfth work W and the machining of the thirteenth work W after the machining of the twelfth work W. Control is performed so that blank machining is performed before and after the start. The operation execution unit 23 stops the operation of the machine tool 100 after processing the 13th workpiece W.

  As described above, the operation execution unit 23 determines the machining interval of the work W when the thermal displacement in the machine tool 100 is predicted to be large, for example, when the machine tool 100 starts operating by turning on the power or restarting the operation. shorten. After that, when it is predicted that the thermal displacement in the machine tool 100 will be small, the machining interval of the work W is lengthened. The operation execution unit 23 stops the operation of the machine tool 100 after processing the thirteenth work W.

  As shown in FIG. 5, the deviation of the first work W from the design value (desired value) is 0, but the deviation increases with the passage of time. Further, it is shown that when the operation stop of the machine tool 100 is sandwiched, the deviation amount becomes small once, but the deviation becomes large with the lapse of time from the restart of the operation. The deviation of the 13th work W is smaller than the deviation of the 12th work W, but the deviation amount from the design value (desired value) is still large. In the continuous adjustment operation, the first temperature t1 to the fifth temperature t5 are measured at the timing of processing the work W.

  The coefficient adjusting unit 24 is based on the dimension of the workpiece W after machining during the adjustment continuous operation, the displacement amount which is a deviation from the design value, and the first temperature t1 to the fifth temperature t5 at the timing of machining the workpiece W. Then, the coefficient used for estimating the predetermined thermal displacement amount of the predetermined correction formula is adjusted so as to reduce the displacement amount. In the present embodiment, the coefficient adjusting unit 24 determines the coefficients K1 and K2 used for estimating the spindle axial thermal displacement amount Δθs, the coefficients K3 and K4 used for estimating the mounting position thermal displacement amount Δθt, and the outside air factor thermal displacement amount. Each coefficient K5 used for estimation is adjusted. The adjustment of the coefficients K1 to K5 is performed, for example, by substituting previously prepared values for the coefficients K1 to K5 and selecting the combination of the coefficients K1 to K5 that minimizes the displacement amount.

  FIG. 6 is a graph showing the predetermined thermal displacement amount before and after the coefficient adjustment by the coefficient adjusting unit 24. The horizontal axis of FIG. 6 indicates the elapsed time since the power of the machine tool 100 was turned on. The vertical axis of FIG. 6 indicates the amount of displacement of the diameter of the work W after processing. The value 0 on the vertical axis in FIG. 6 is a value that does not deviate from the design value (no thermal displacement). It shows the gap. As shown in FIG. 6, the work W is processed with the correction value after the coefficient adjustment (the predetermined correction expression after the coefficient adjustment) as compared with the case where the work W is processed with the correction value before the coefficient adjustment (the predetermined correction expression). In this case, it is confirmed that the deviation from the design value of the work W after processing has become smaller during the period of 8 hours from the start of operation.

  The input unit 26 can input the dimensions of the work W after processing during the continuous adjustment operation. As the input unit 26, for example, an input interface such as a keyboard, a mouse, a touch panel can be used. The input result of the input unit 26 is sent to the coefficient adjusting unit 24 of the control device 2. When the size of the work W is input by the input unit 26, the coefficient adjusting unit 24 determines the coefficient K1 in the previously set predetermined correction formula based on each size of the work W input by the input unit 26. To K5 respectively.

  The display unit 27 can display predetermined information output from the control device 2. As the display unit 27, for example, a display device such as a liquid crystal panel or an organic electroluminescence panel is used. For example, the coefficient adjusting unit 24 outputs the input result from the input unit 26 to the display unit 27, so that the display unit 27 can display the input result in the input unit 26.

  FIG. 7 is a diagram showing an example of a display screen displayed on the display unit 27. In the example shown in FIG. 7, the display screen G of the display unit 27 displays an input field R for inputting the work diameter of each of the 13 works W to be machined during the continuous operation for adjustment. . In the input field R, work numbers of consecutive numbers 1 to 13 are given according to the processing order of the work W. The operator operates the input unit 26 to input the size of each work W in the input field R. In this way, the worker can execute the adjustment of the coefficients K1 to K5 by a simple work such as inputting the size of the work W in the input field R using the input unit 26.

  In the control device 2, the movement control unit 21, the calculation unit 22, the operation execution unit 23, and the coefficient adjustment unit 24 may be realized by software. Further, in the control device 2, at least one of the movement control unit 21, the calculation unit 22, the operation execution unit 23, and the coefficient adjustment unit 24 may be configured by another control device. Further, as the storage unit 25, for example, a hard disk built in the control device 2, a portable CD-ROM, a USB memory, or the like may be used.

  Next, the operation of the machine tool 100 configured as above will be described. First, the work W to be processed is held on the spindle 10 by the grip claws 11a. After holding the workpiece W on the spindle 10, the control device 2 rotates the spindle 10 in the axial direction (θZ direction) of the spindle axis AX1 to rotate the workpiece W in the axial direction of the spindle axis AX1. Let

  Subsequently, the control device 2 controls the X-direction driving unit 64 and the Z-direction driving unit 65 by the movement control unit 21 to relatively move the work W and the cutting tool T, so that the work W is moved at the cutting edge Ta of the cutting tool T. To cut. The processing data relating to the relative movement amount and speed of the work W and the blade T are stored in the storage unit 25 or the like by, for example, transmission from a host controller or input by a worker. The processing data is, for example, coordinate data of a trajectory along which the cutting edge Ta of the cutting tool T should move. The movement control unit 21 drives the X-direction drive unit 64 and the Z-direction drive unit 65 based on the processing data of the storage unit 25 and the like.

  When the work W is cut, the headstock 4, the tool rest 5, the spindle 10, the turret 50, the tool T, due to a change in environmental temperature, cutting heat generated when the work W is cut, heat generated in each part during operation, and the like. The holder 51, the bed 3, and the like are thermally deformed, and the distance in the X direction between the spindle axis AX1 and the blade tip Ta of the blade T changes. Due to this variation in the distance, an initially set reference position or reference distance (for example, a distance L in the X direction between the spindle axis AX1 and the cutting edge Ta, etc.) changes, and the cutting edge Ta of the cutting tool T with respect to the workpiece W changes. The position deviates from the expected value (set value based on the processed data). Therefore, in the present embodiment, the calculation unit 22 calculates or estimates the thermal displacement amount, calculates the correction value ΔX that is the relative movement amount between the spindle 10 and the cutting tool T, and corrects the machining data.

  FIG. 8 is a flowchart showing an example of processing for calculating the correction value of the distance L. As shown in FIG. 8, the calculation unit 22 calculates the headstock thermal displacement amount ΔS based on the displacement (position) of the spindle axis AX1 in the X direction measured by the spindle-side position measuring device 71. Is calculated (step S01). Further, the calculation unit 22 calculates the tool post thermal displacement amount ΔT based on the displacement (position) in the X direction of the third reference position P3 measured by the tool side position measurement device 72 (step S02). Further, the calculation unit 22 estimates the blade thermal displacement amount ΔH based on the temperature of the pipe 32 (first temperature) measured by the first temperature measuring device 73 (step S03).

  As described above, the calculation unit 22 estimates the spindle shaft center thermal displacement amount Δθs based on the temperature of the headstock 4 (second temperature) measured by the second temperature measuring device 74 (step S04). Further, the calculation unit 22 estimates the mounting position thermal displacement amount Δθt from the temperature of the pipe 32 (first temperature) measured by the first temperature measuring device 73 (step S05). Further, the calculation unit 22 estimates the outside air factor thermal displacement amount ΔG based on the temperature inside the cover C (third temperature) measured by the third temperature measuring device 79 (step S06).

  The calculation unit 22 calculates or estimates the headstock thermal displacement amount ΔS, the tool post thermal displacement amount ΔT, the blade tool thermal displacement amount ΔH, the spindle shaft center thermal displacement amount Δθs, the attachment position thermal displacement amount Δθt, and the outside air factor thermal displacement amount ΔG. Based on, the correction value ΔX (ΔX = ΔS + ΔT + ΔH + Δθs + Δθt + ΔG), which is the relative movement amount between the spindle axis AX1 of the spindle 10 and the cutting edge Ta of the tool T, is calculated (step S07).

  The movement control unit 21 corrects the processing data based on the relative movement amount (correction value ΔX) calculated by the calculation unit 22, and controls the X-direction driving unit 64 and the Z-direction driving unit 65 based on the corrected processing data. The workpiece W is driven to cut the workpiece W (step S08). In step S08, since the work W is cut based on the corrected working data, the heat of the machine tool 100 (main body 1) is cut in the X direction (cut amount of the work W) and the Z direction (feed amount of the cutting edge Ta). The work W is processed by eliminating the influence of deformation, and the work W can be accurately cut to a desired dimension.

  When the cutting of the work W is completed, the holding by the grip claws 11 a is released and the work W is taken out from the spindle 10. The work W may be loaded into or unloaded from the spindle 10 by a work transfer device (not shown). The series of operations from the loading and unloading of the work W by the work transporting device may be performed, for example, by an instruction from the control device 2 or may be performed manually by an operator. Since the control device 2 performs a series of operations from the loading and unloading of the work W by the work transfer device, the work W can be processed automatically.

  In addition, the operation execution unit 23 executes the adjustment continuous operation (step S09). In step S09, the operation executing unit 23 may execute the adjustment continuous operation according to a predetermined schedule, or may execute the adjustment continuous operation according to an execution instruction from an operator or the like. For example, the operation execution unit 23 may execute the continuous adjustment operation on holidays or holidays when the operation of the factory or the like is stopped, or at the timing when the workpiece W to be processed has changed or the blade T has been exchanged. You may let me.

  FIG. 9 is a flowchart showing an example of the adjustment continuous operation. As shown in FIG. 9, the operation execution unit 23 determines whether or not to execute the adjustment continuous operation (step S11). In step S11, the operation execution unit 23 determines, for example, whether or not there is a flag for performing the adjustment continuous operation in the machining program, and controls to execute the adjustment continuous operation if the flag is present (step S11). Yes). In addition, for example, when there is no flag described above, the operation execution unit 23 determines not to execute the continuous adjustment operation (NO in step S11), and repeats the process of step S11. In addition, as the above-mentioned flag, for example, when a predetermined period has elapsed since the machine tool 100 was operated by a timer or the like, or when an operator or the like inputs from the input unit 26 that the continuous adjustment operation is performed. Etc.

  When executing the adjustment operation (YES in step S11), the operation execution unit 23 starts processing one work W (step S12). In step S12, the operation execution unit 23 controls the operation of the headstock 4 and the tool rest 5 using the correction value ΔX calculated by the preset predetermined correction formula. After processing one workpiece, the operation execution unit 23 executes idle processing (step S13). In step S13, the operation executing unit 23 causes the grip claw 11a not to grip the work W or does not cut the work W gripped by the grip claw 11a with the tool T, the spindle 10, the headstock 4, and the tool rest. Drive 5 The operation execution unit 23 determines whether or not a predetermined time has passed since the idle machining was executed (step S04). When the predetermined time has not elapsed (NO in step S14), the operation executing unit 23 continues the idle machining.

  When the predetermined time has elapsed (YES in step S14), the operation execution unit 23 determines whether the number of processed works W has reached the predetermined number (step S15). When the operation executing unit 23 determines that the number of processed workpieces W has not reached the predetermined number (NO in step S15), the operation executing unit 23 returns to step S12 described above to process one workpiece W, and the processed workpieces W are processed. The operation of steps S12 to S14 is controlled to be repeated until W reaches a predetermined number. When the operation executing unit 23 determines that the number of processed works W has reached the predetermined number (YES in step S15), the size of the processed work W is input (step S16), and the continuous adjustment operation is ended. To do. In step S16, the size of the work W after processing may be input by an operator using the input unit 26, or may be automatically sent from a measuring device that measures the size of the work W and input. It may be in any form.

  After executing the adjustment continuous operation in step S09, as shown in FIG. 8, the coefficient adjustment unit 24 determines, based on the displacement amount between the design value and the dimension of the work W after machining during the adjustment continuous operation, The coefficients K1 to K5 of the predetermined correction formula used for estimating the predetermined thermal displacement amount are adjusted so as to reduce the displacement amount (step S10). After the coefficients K1 to K5 are adjusted, the control device 2 may control to perform new cutting using the correction value calculated by the predetermined correction equation after the coefficient adjustment.

  As described above, the machine tool 100 according to the embodiment executes the above-described adjustment continuous operation, and based on the displacement amount between the dimension of the work W after machining and the design value during the adjustment continuous operation, this displacement is performed. Since the coefficients K1 to K5 used for estimating the predetermined thermal displacement amount of the predetermined correction formula are adjusted so as to reduce the amount, the distance L between the spindle axis AX1 and the cutting edge Ta is corrected according to the displacement due to thermal deformation. The value can be adjusted according to the machine tool 100, and the work W can be processed with high precision.

  A specific example in which the above-described embodiment is applied to four machine tools 100A, 100B, 100C, and 100D will be described. The machine tools 100A to 100D each have the same configuration as the machine tool 100 described above. Further, the machine tools 100A to 100D are provided with a predetermined correction formula (hereinafter, this predetermined correction formula is referred to as a reference correction formula) prepared in advance. This reference correction formula is calculated using another machine tool different from the machine tools 100A to 100D. This other machine tool also has the same configuration as the machine tool 100 described above.

  FIG. 10A is a graph showing the amount of thermal displacement before and after the adjustment of the coefficients K1 to K5 for the machine tool 100A, and FIG. 10B is the predetermined amount of thermal displacement before and after the adjustment of the coefficients K1 to K5 for the machine tool 100B. It is a graph which shows. FIG. 11A is a graph showing a predetermined thermal displacement amount before and after the adjustment of the coefficients K1 to K5 for the machine tool 100C, and FIG. 11B is a predetermined thermal displacement amount before and after the adjustment of the coefficients K1 to K5 for the machine tool 100D. It is a graph which shows quantity. In FIGS. 10 and 11, the horizontal axis represents the elapsed time from the power-on of the machine tools 100A to 100D, and the vertical axis represents the displacement amount (deviation) of the diameter of the work W with respect to the design value. The 0 on the vertical axis in FIGS. 10 and 11 indicates a value that does not deviate from the design value (no thermal displacement). The deviation on the decreasing side is shown.

  In FIGS. 10 (A) and (B) and FIGS. 11 (A) and (B), the dotted line is the displacement amount when the correction value calculated by the reference correction formula before the coefficient adjustment is used, and the solid line is It is the displacement amount when the correction value calculated by the reference correction formula after the coefficient adjustment is used. As shown by the dotted lines in FIGS. 10 (A) to 11 (B), when the correction values calculated by the reference correction formula are applied to the machine tools 100A to 100D, different displacements are shown with the passage of time. The displacement range of is large. That is, when the common reference correction formula is applied to each machine tool 100A or the like, it is necessary to produce (work) the work W due to a working error in a large range (for example, ± 15 μm range) with respect to the design value. Although it is possible, it is not possible to realize highly accurate production with a smaller processing error (close to the design value).

  According to the present embodiment, since the correction value calculated by the correction formula (predetermined correction formula) in which the coefficients K1 to K5 are adjusted is used for each of the machine tools 100A to 100D, FIGS. 10 (A) to 11 (B). As shown by the solid line, the range of displacement is small. That is, the work W can be processed (produced) due to a processing error within a small range (for example, a range of ± 5 μm) with respect to the design value, and high-precision processing with a small processing error (close to the design value) can be performed. Can be realized. Therefore, it can be said that the machine tools 100A to 100D are tuned so that the work W can be machined with high accuracy by adjusting the coefficients K1 to K5, respectively.

  Although the embodiment has been described above, the present invention is not limited to the above description, and various modifications can be made without departing from the scope of the present invention. For example, in the above-described embodiment, the spindle shaft center thermal displacement amount Δθs is estimated from the second temperature, but the present invention is not limited to this form. For example, the spindle shaft center thermal displacement amount Δθs may be estimated from the elapsed time from the start of operation of the machine tool. The amount of thermal displacement Δθs of the spindle axis increases from the start of operation to a predetermined value. The relationship between the time from the start of operation and the amount of thermal displacement Δθs of the spindle shaft core is stored in the storage unit 25 as, for example, function data of the amount of thermal displacement Δθs of the spindle shaft with the time from the start of operation as a variable. May be. In this case, the calculation unit 22 may use the function data stored in the storage unit 25 to calculate the spindle shaft center thermal displacement amount Δθs corresponding to the time from the start of operation.

  As described above, when the value of the thermal displacement amount Δθs of the spindle axis has a correlation with the time from the start of operation of the machine tool, the time from the start of operation is measured and Since it suffices to calculate the corresponding spindle shaft center thermal displacement amount Δθs, the second temperature measuring device 74 for measuring the second temperature becomes unnecessary. With this configuration, the device configuration of the main body 1 and the processing of the control device 2 can be simplified.

P1 ... 1st reference position P2 ... 2nd reference position P3 ... 3rd reference position T ... Blade Ta ... Blade edge W ... Work AX1 ... Spindle axis 1 ... Main body 2 ... Control device 3 ... Bed 4 ... Headstock 5 ... Tool rest 5b ... Side surface 5c ... Fixed position 6 ... Moving device 7 ... Measuring device 10 ... ..Spindle 11 ... Chuck drive unit 11a ... Gripping claw 21 ... Movement control unit 22 ... Calculation unit 23 ... Operation execution unit 24 ... Coefficient adjustment unit 26 ... Input unit 30・ ・ ・ Cooling device 32 ・ ・ ・ Piping 50 ・ ・ ・ Turret 50a ・ ・ ・ End face 70 ・ ・ ・ Reference frame 71 ・ ・ ・ Spindle side position measuring device 71a ・ ・ ・ First scale 71b ・ ・ ・ First reading device 72 ... Blade side position measuring device 72a ... Second scale 72b ... Second reading device 73 ... The first temperature measuring device 74 ... second temperature measuring device 79 ... third temperature measuring device 75 ... fourth temperature measuring device 76 ... fifth temperature measuring device 100 ... machine tool

Claims (6)

A spindle stock that rotatably supports a spindle having a chuck for gripping a work piece at the tip,
A turret to which a turret can be attached,
A bed in which the headstock and the tool rest are installed so as to be relatively movable in the radial direction of the main shaft,
The tool post, the spindle head, or a temperature measuring device for measuring the temperature in the vicinity thereof,
A spindle side position measuring device that measures a spindle axis center position in the spindle radial direction with respect to a first reference position in the bed;
A tool-side position measuring device that measures a third reference position of the tool rest in a radial direction of the spindle with respect to a second reference position in the bed,
A headstock thermal displacement amount, which is a thermal displacement amount of the headstock, is calculated based on the spindle shaft center position measured by the spindle-side position measuring device, and the third reference measured by the tool-side position measuring device. Calculate the amount of tool rest thermal displacement that is the amount of thermal displacement of the tool rest based on the position, and estimate the predetermined amount of thermal displacement from the workpiece to the machining tip of the tool based on the temperature measured by the temperature measuring device. Then, the headstock thermal displacement amount, the tool rest thermal displacement amount, and a calculation unit for calculating the relative movement amount of the headstock and the tool rest by a predetermined correction formula having each item of the predetermined thermal displacement amount,
An operation for performing a continuous adjustment operation for intermittently machining a plurality of workpieces while sandwiching a blank machining that drives the spindle, the spindle headstock, and the tool rest without cutting the workpiece while using the predetermined correction formula. Execution section,
Based on the displacement of the workpiece after machining during the adjustment continuous operation and the design value, the coefficient used to estimate the predetermined thermal displacement of the predetermined correction formula so as to reduce the displacement. A machine tool including a coefficient adjusting unit for adjusting. The temperature measuring device,
A first temperature measuring device for measuring the temperature of the tool post or the vicinity thereof,
A second temperature measuring device for measuring one or more temperatures of the headstock and / or the vicinity thereof,
The arithmetic unit, as the predetermined thermal displacement amount,
A blade thermal displacement amount which is a thermal displacement amount from the third reference position to the machining tip of the blade based on the first temperature measured by the first temperature measuring device,
A spindle axis thermal displacement amount which is a thermal displacement amount of the spindle axis with respect to a reading reference provided in the spindle side position measuring device from the second temperature measured by the second temperature measuring device;
Estimating the mounting position thermal displacement amount, which is the thermal displacement amount of the tool mounting position of the tool rest relative to the third reference position, from the first temperature measured by the first temperature measuring device, respectively,
The machine tool according to claim 1, wherein the coefficient adjusting unit adjusts each coefficient used for estimating the spindle shaft center thermal displacement amount and the attachment position thermal displacement amount in the predetermined correction formula. The temperature measuring device includes a third temperature measuring device that measures a temperature corresponding to an outside air temperature around the tool rest and the headstock,
As the predetermined thermal displacement amount, the calculation unit estimates an outside air factor thermal displacement amount that is a thermal displacement amount between the spindle axis and the machining tip of the blade from the third temperature measured by the third temperature measuring device. ,
The machine tool according to claim 2, wherein the coefficient adjusting unit adjusts the coefficient used for estimating the outside air factor thermal displacement amount in the predetermined correction formula. Equipped with an input unit capable of inputting the dimensions of the workpiece after machining during the continuous operation for adjustment,
The machine tool according to any one of claims 1 to 3, wherein the coefficient adjusting unit adjusts the coefficient based on a dimension of the workpiece input to the input unit.   The machine tool according to any one of claims 1 to 4, wherein the operation executing unit sets the number of workpieces to be machined within a range in which a machining tip of the cutting tool is not or hardly worn. A spindle stock that rotatably supports a spindle having a chuck for gripping a work piece at the tip,
A turret to which a turret can be attached,
A bed in which the headstock and the tool rest are installed so as to be relatively movable in the radial direction of the main shaft,
The tool post, the spindle head, or a temperature measuring device for measuring the temperature in the vicinity thereof,
A spindle side position measuring device that measures a spindle axis center position in the spindle radial direction with respect to a first reference position in the bed;
A tool-side position measuring device that measures a third reference position of the tool post in the radial direction of the spindle with respect to a second reference position in the bed, a machining method using a machine tool,
Calculating a headstock thermal displacement amount, which is a thermal displacement amount of the headstock, based on the spindle shaft center position measured by the spindle-side position measuring device;
Calculating a tool post thermal displacement amount that is a thermal displacement amount of the tool post based on the third reference position measured by the tool side position measuring device;
Estimating a predetermined amount of thermal displacement from the workpiece to the processing tip of the blade based on the temperature measured by the temperature measuring device,
Calculating the relative movement amount of the headstock and the tool rest by a predetermined correction formula having the headstock thermal displacement amount, the tool rest heat displacement amount, and the predetermined heat displacement amount as items,
Performing an adjustment continuous operation for intermittently machining a plurality of workpieces while sandwiching a blank machining that drives the spindle, the spindle headstock, and the tool rest without cutting the workpiece while using the predetermined correction formula. When,
Based on the displacement of the workpiece after machining during the adjustment continuous operation and the design value, the coefficient used to estimate the predetermined thermal displacement of the predetermined correction formula so as to reduce the displacement. A processing method including adjusting.

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