Machine tool

Abstract

A machine tool is provided with: a movable object (30); a linear guide (51) including a guide rail (61) and a slider (65) attached to the movable object (30) and slidable along the guide rail (61), and configured to guide the movable object (30) in a moving direction of the movable object (30); and a temperature sensor (81) provided in the slider (65) and configured to detect a temperature of the slider (65).

Description

Technical Field

[0001] This invention relates to a machine tool. Background Technology

[0002] For example, Japanese Patent Application Publication No. 2013-234978 (Patent Document 1) discloses a machine tool including a column mounted on a bed, a spindle head having a spindle, and a saddle having a worktable. The spindle head is supported on the front surface of the column and is movable in the vertical direction (Z-axis direction). The saddle is movable back and forth in the horizontal direction (Y-axis direction) and is provided with a worktable. The worktable is movable left and right in the horizontal direction (X-axis direction).

[0003] [Existing Technical Documents]

[0004] [Patent Literature]

[0005] Patent Document 1: Japanese Patent Application Publication No. 2013-234978 Summary of the Invention

[0006] The problem the invention aims to solve

[0007] As disclosed in Patent Document 1 above, known machine tools include a movable object that can move in a linear direction. In such machine tools, in order to further improve the machining accuracy of the workpiece, it is necessary to position the movable object to a target movement position defined by the NC program with higher precision.

[0008] The purpose of this invention is to provide a machine tool that can position a movable object to a target moving position with higher precision.

[0009] Solution for solving the problem

[0010] A machine tool according to one aspect of the invention includes: a movable object; a linear guide including a guide rail and a slider attached to the movable object and slidable along the guide rail, and the linear guide being configured to guide the movable object in a direction of movement of the movable object; and a temperature sensor disposed in the slider and configured to detect the temperature of the slider.

[0011] According to another aspect of the invention, a machine tool includes: a base; a movable object movable relative to the base; a linear guide including a guide rail and a slider attached to the movable object and slidable along the guide rail, and the linear guide being configured to guide the movable object in a direction of movement; and a temperature sensor disposed in the slider and configured to detect the temperature of the slider.

[0012] A machine tool according to another aspect of the invention includes: a base; a movable object having a guide member guided by the base and movable relative to the base; a temperature sensor disposed in the guide member and configured to detect the temperature of the guide member; a servo motor serving as a power source for moving the movable object; and a controller controlling the servo motor based on a position command indicative of a target movement position of the movable object. The controller corrects the position command based on the temperature of the guide member detected by the temperature sensor.

[0013] The effects of the invention

[0014] According to the present invention, a machine tool capable of positioning a movable object to a target moving position with higher precision can be provided. Attached Figure Description

[0015] [ Figure 1 ] Figure 1 This is a perspective view showing a machine tool according to a first embodiment of the present invention.

[0016] [ Figure 2 ] Figure 2 yes Figure 1 A perspective view of the guiding mechanism and position detection mechanism in the machine tool shown.

[0017] [ Figure 3 ] Figure 3 yes Figure 2 An exploded view of the guiding mechanism and the position detection mechanism shown.

[0018] [ Figure 4 ] Figure 4 yes Figure 2 The cross-sectional view of the slider is shown.

[0019] [ Figure 5 ] Figure 5 It is shown Figure 1 The diagram shows the functional structure of the machine tool's control system.

[0020] [ Figure 6 ] Figure 6 It is shown Figure 5 A graph of the coefficient table in the figure.

[0021] [ Figure 7 ] Figure 7 This is a flowchart illustrating the control process of a servo motor.

[0022] [ Figure 8 ] Figure 8 This is a table showing the change of relative displacement along the X-axis over time during the reciprocating movement of the column in the first verification experiment.

[0023] [ Figure 9 ] Figure 9 This is a table showing the change of relative displacement in the Y-axis direction over time during the reciprocating movement of the column in the second verification experiment.

[0024] [ Figure 10 ] Figure 10 This is a cross-sectional view showing a machine tool according to a second embodiment of the present invention.

[0025] [ Figure 11 ] Figure 11 This is a perspective view showing the mounting position of a temperature sensor in the guide mechanism of a machine tool according to a third embodiment of the present invention, which differs from... Figure 2 The installation location.

[0026] [ Figure 12 ] Figure 12 This is a side view showing a machine tool according to a fourth embodiment of the present invention.

[0027] [ Figure 13 ] Figure 13 It is shown Figure 12 The diagram shows the functional structure of the machine tool's control system.

[0028] [ Figure 14 ] Figure 14 It is shown Figure 13 A graph of the coefficient table in the figure.

[0029] [ Figure 15 ] Figure 15 This is a side view showing a machine tool according to a fifth embodiment of the present invention.

[0030] [ Figure 16 ] Figure 16 It is shown Figure 15 The diagram shows the functional structure of the machine tool's control system.

[0031] [ Figure 17 ] Figure 17 It is shown Figure 16 A graph of the coefficient table in the figure.

[0032] [ Figure 18 ] Figure 18 This is a side view showing a machine tool according to a sixth embodiment of the present invention.

[0033] [ Figure 19 ] Figure 19 It is shown Figure 18 The diagram shows the functional structure of the machine tool's control system.

[0034] [ Figure 20 ] Figure 20 It is shown Figure 19 A graph of the coefficient table in the figure. Detailed Implementation

[0035] Embodiments of the invention will be described with reference to the accompanying drawings. In the following drawings, the same or corresponding components will be indicated by the same reference numerals.

[0036] (First Implementation)

[0037] Figure 1 This is a perspective view showing a machine tool according to a first embodiment of the present invention. (Reference) Figure 1 Machine tool 100 is a machining center that processes workpieces by bringing a rotary cutting tool into contact with the workpiece. Machine tool 100 is a horizontal machining center, meaning that the axis of rotation of the rotary cutting tool extends in the horizontal direction. Machine tool 100 is an NC (numerical control) machine tool, which is controlled by a computer according to numerical control to automatically perform various machining operations on the workpiece.

[0038] In this specification, the axis parallel to the horizontal direction and parallel to the rotation axis of the tool is called the "Z-axis," the axis parallel to the horizontal direction and orthogonal to the Z-axis is called the "X-axis," and the axis parallel to the vertical direction is called the "Y-axis." In the front view of the spindle 21 described later, the leftward direction is called the "+X-axis direction," and the rightward direction is called the "-X-axis direction." In the front view of the spindle 21, the forward direction is called the "+Z-axis direction," and the backward direction is called the "-Z-axis direction." The upward direction is called the "+Y-axis direction," and the downward direction is called the "-Y-axis direction."

[0039] Machine tools using this invention are not limited to horizontal machining centers, but can be, for example, vertical machining centers, lathes that rotate the workpiece and machine it by bringing a cutting tool into contact with the workpiece, or composite machines capable of performing turning operations using a fixed cutting tool and milling operations using a rotating cutting tool. Machine tools using this invention can be AM / SM hybrid machines capable of performing both additive manufacturing (AM) and subtractive manufacturing (SM) on a workpiece.

[0040] The machine tool 100 includes a bed 12, a column 31, a spindle head 22, and a worktable 41.

[0041] The bed 12 is a base component used to support the column 31, spindle head 22, worktable 41, etc., and is fixed to the factory floor or the like. The bed 12 is made of metal such as cast iron.

[0042] The column 31 is supported by the bed 12. The column 31 as a whole has a portal shape that rises upward from the bed 12. The column 31 is located at the end of the bed 12 in the -Z axis direction. The column 31 can move in the X axis direction through various feed mechanisms, guide mechanisms, servo motors, etc.

[0043] The spindle head 22 is supported by the column 31. The spindle head 22 has a columnar shape that protrudes from the column 31 along the +Z axis. The spindle head 22 can move in the Y-axis direction through various feed mechanisms, guide mechanisms, servo motors, etc.

[0044] The spindle head 22 has a spindle (tool spindle) 21. The spindle 21 can be rotated by a motor about a rotation axis 101 parallel to the Z-axis. The spindle 21 has a built-in clamping mechanism for holding a tool used to machine a workpiece in the machine tool 100. When the spindle 21 rotates, the tool held by the spindle 21 rotates about the rotation axis 101.

[0045] The worktable 41 is supported by the bed 12. The worktable 41 is mounted on the bed 12. The worktable 41 is positioned away from the column 31 in the +Z axis direction. The worktable 41 is configured to hold the workpiece. The worktable 41 holds the workpiece in a position facing the spindle 21 along the Z axis direction. The worktable 41 can move in the Z axis direction via various feed mechanisms, guide mechanisms, servo motors, etc. The worktable 41 has a built-in rotation mechanism for rotating a pallet mounted on the worktable 41 about a rotation axis extending in the Y-axis direction (vertical direction).

[0046] Using this structure, the position of the workpiece to be machined by the tool can be moved in three dimensions by a combination of the movement of the column 31 in the X-axis direction, the movement of the spindle head 22 (spindle 21) in the Y-axis direction, and the movement of the worktable 41 in the Z-axis direction.

[0047] Each of the column 31, spindle head 22, and worktable 41 corresponds to the movable object 30. The column 31, serving as the movable object 30, is movable relative to the bed 12, serving as the base 10. The spindle head 22, serving as the movable object 30, is movable relative to the column 31, serving as the base 10. The worktable 41, serving as the movable object 30, is movable relative to the bed 12, serving as the base 10.

[0048] Figure 2 yes Figure 1 A perspective view of the guiding mechanism and position detection mechanism in the machine tool shown. Figure 3 yes Figure 2 An exploded view of the guiding mechanism and the position detection mechanism in the diagram.

[0049] refer to Figures 1 to 3 The machine tool 100 also includes linear guides 51 (51A, 51B) and a linear scale 71. The linear guides 51 constitute a guiding mechanism for guiding the movable object 30 in the direction of movement of the movable object 30. The linear scale 71 constitutes a position detection mechanism for detecting the position of the movable object 30.

[0050] Linear guides 51 and linear scales 71 are provided for each movable object 30 of column 31, spindle head 22 (spindle 21) and worktable 41.

[0051] A linear guide 51 is provided for the column 31 to guide the column 31 in the X-axis direction. The machine tool 100 includes linear guides 51A and 51B as linear guides 51 for guiding the column 31 in the X-axis direction. Linear guides 51A and 51B are spaced apart from each other in the Z-axis direction, which is orthogonal to the X-axis direction (i.e., the direction of movement of the column 31). A linear scale 71 is provided for the column 31 to detect the position of the column 31 in the X-axis direction.

[0052] A linear guide 51 provided on the spindle head 22 guides the spindle head 22 in the Y-axis direction. The machine tool 100 includes linear guides 51A and 51B as linear guides 51 that guide the spindle head 22 in the Y-axis direction. Linear guides 51A and 51B are spaced apart from each other in the X-axis direction, which is orthogonal to the Y-axis direction (i.e., the direction of movement of the spindle head 22). A linear scale 71 provided on the spindle head 22 detects the position of the spindle head 22 in the Y-axis direction.

[0053] A linear guide 51 is provided for the worktable 41 to guide the worktable 41 in the Z-axis direction. The machine tool 100 includes linear guides 51A and 51B as linear guides 51 for guiding the worktable 41 in the Z-axis direction. Linear guides 51A and 51B are spaced apart from each other in the X-axis direction, which is orthogonal to the Z-axis direction (i.e., the direction of movement of the worktable 41). A linear scale 71 is provided for the worktable 41 to detect the position of the worktable 41 in the Z-axis direction.

[0054] The linear guides 51 and linear scales 71 provided for each movable object 30 of the column 31, spindle head 22, and worktable 41 have essentially the same structure. In the following text, as... Figure 2 and Figure 3 As shown, the structure of the linear guide 51 that describes the guide post 31 in the X-axis direction and the structure of the linear scale 71 that detects the position of the post 31 in the X-axis direction are used as examples.

[0055] like Figure 2 and Figure 3 As shown, the linear guide 51 includes a guide rail 61 and sliders 65 (65J, 65K).

[0056] The guide rail 61 extends in the X-axis direction. The guide rail 61 is attached to the bed 12. The guide rail 61 is fastened to the bed 12 using bolts or the like. The guide rail 61 is made of metal. In a cross-section taken along the YZ plane, the central portion of the guide rail 61 in the Y-axis direction is narrower in the Z-axis direction.

[0057] The slider 65 is attached to the post 31. The slider 65 is fastened to the post 31 using bolts or the like. The slider 65 is capable of sliding along the guide rail 61 in the X-axis direction. In a cross-section taken along the YZ plane, the slider 65 opens towards the -Y-axis direction and has a concave shape to receive the guide rail 61 therein.

[0058] Slider 65J and slider 65K are spaced apart from each other in the X-axis direction (i.e., the direction of movement of column 31).

[0059] The slider 65 includes a body 66 and resin components 67 (67p, 67q). The body 66 is made of metal. The body 66 engages with the guide rail 61 via rolling elements (not shown), such as a plurality of balls or rollers. The body 66 is fastened to the post 31. The resin components 67 are made of resin such as polyacetal resin (POM resin). The resin components 67 are adjacent to the body 66 in the X-axis direction (i.e., the direction of movement of the post 31). The resin components 67 are connected to the body 66. The length of the resin components 67 in the X-axis direction is less than the length of the body 66 in the X-axis direction.

[0060] Resin component 67p is connected to the side surface of the main body 66 facing the +X-axis direction. Resin component 67q is connected to the side surface of the main body 66 facing the -X-axis direction. The resin components 67q of slider 65J and 67p of slider 65K face each other in the X-axis direction.

[0061] The linear scale 71 includes a scale unit 72 and a head unit 76. The scale unit 72 records scale markings (not shown). The scale unit 72 is mounted on the guide rail 61. The scale unit 72 is not limited to being mounted on the guide rail 61, but can also be mounted on the bed 12 near the guide rail 61. The head unit 76 is movable integrally with the column 31 in the X-axis direction. The head unit 76 can read the scale markings recorded on the scale unit 72.

[0062] The scale unit 72 includes a base member 73, a scale body 74, and a cover 75. The base member 73 extends in the X-axis direction. The base member 73 is mounted on the top surface of the guide rail 61. The scale body 74 is made of an elongated magnetic body that is longer in the X-axis direction and has scale markings magnetically recorded on it. The scale markings are engraved at equal intervals in the X-axis direction. The scale body 74 is supported on the base member 73. The cover 75 is attached to the base member 73 to cover the scale body 74. The cover 75 is made of, for example, stainless steel foil.

[0063] Head unit 76 is attached to post 31. Head unit 76 is fastened to post 31 using bolts or the like. Slider 65J, head unit 76, and slider 65K are spaced apart from each other in the X-axis direction. Head unit 76 is positioned between slider 65J and slider 65K in the X-axis direction. The distance between head unit 76 and slider 65J in the X-axis direction may be the same as or different from the distance between head unit 76 and slider 65K in the X-axis direction. Head 76 is provided with a tunneling magnetoresistive (TMR) sensor (not shown) for reading scale marks recorded on scale unit 72. Head unit 76 does not contact linear guide 51. The TMR sensor is positioned on the bottom surface of head unit 76, facing scale unit 72, and a gap is inserted between the TMR sensor and scale unit 72 in the Y-axis direction.

[0064] As column 31 moves in the X-axis direction, head unit 76 moves in the X-axis direction while maintaining a constant distance to sliders 65J and 65K. Head 76 moves in the X-axis direction while facing scale unit 72, and a constant distance is maintained between head 76 and scale unit 72. A TMR sensor disposed in head unit 76 moves in the X-axis direction while facing scale body 74 and reads scale marks recorded on scale body 74, with cover 75 positioned between the TMR sensor and scale body 74.

[0065] Figure 4 yes Figure 2 The cross-sectional view of the slider is shown. (Reference) Figures 2 to 4 The machine tool 100 also includes a temperature sensor 81. For example, the temperature sensor 81 may be a thermistor.

[0066] Temperature sensor 81 is installed in slider 65. Temperature sensor 81 detects the temperature of slider 65. Temperature sensor 81 is installed in slider 65J. Temperature sensor 81 detects the temperature of slider 65J. No temperature sensor 81 is installed in slider 65K.

[0067] like Figure 4 As shown, temperature sensor 81 is supported by resin member 67 in contact with body 66. Temperature sensor 81 is supported by resin member 67q of slider 65J. Resin member 67 is provided with hole 68. Hole 68 extends through resin member 67 in the X-axis direction. Temperature sensor 81 is disposed in hole 68. The end of temperature sensor 81 in the X-axis direction contacts body 66. Note that hole 68 is initially configured as a channel for supplying lubricating oil to rolling element. In slider 65J, where resin member 67q is configured to support temperature sensor 81, lubricating oil is supplied to rolling element through hole provided in resin member 67p.

[0068] When viewed in the X-axis direction (i.e., the sliding direction of slider 65), temperature sensor 81 can be configured to detect the temperature of the central portion of slider 65 in the Z-axis direction. The end of temperature sensor 81 in the X-axis direction can contact the central portion of body 66 in the Z-axis direction. Temperature sensor 81 is positioned at a location where frictional heat is generated when column 31 moves in the X-axis direction, while TMR sensor is positioned at a location where frictional heat is not generated.

[0069] A linear scale 71 is mounted on the linear guide 51A. The linear scale 71 is not mounted on the linear guide 51B. A temperature sensor 81 is mounted on the slider 65 of the linear guide 51A. The temperature sensor 81 is not mounted on the slider 65 of the linear guide 51B.

[0070] A linear scale 71 can be mounted on both linear guides 51A and 51B. A temperature sensor 81 can be mounted on both slider 65 of linear guide 51A and slider 65 of linear guide 51B. A temperature sensor 81 can also be mounted on both sliders 65J and 65K of each linear guide 51.

[0071] Figure 5 It is shown Figure 1 The diagram shows the functional structure of the machine tool's control system. (Reference) Figure 1 and Figure 5 The machine tool 100 also includes servo motors 141 (141X, 141Y, 141Z), which serve as the power source for moving the movable object 30. Servo motor 141X is the power source for moving the column 31 in the X-axis direction, servo motor 141Y is the power source for moving the spindle head 22 in the Y-axis direction, and servo motor 141Z is the power source for moving the worktable 41 in the Z-axis direction.

[0072] To illustrate the structure of the servo motor 141X, as an example, the servo motor 141X is mounted on the bed 12. The screw of the ball screw, which serves as the feed mechanism, is connected to the output shaft of the servo motor 141, and the nut of the ball screw is connected to the column 31. The rotational motion output from the servo motor 141X is converted into linear motion in the X-axis direction by the ball screw and transmitted to the column 31.

[0073] like Figure 5 As shown, the machine tool 100 also includes a controller 120. The controller 120 controls the operation of the machine tool 100.

[0074] The components of controller 120 are implemented in hardware and software. The hardware includes an arithmetic unit such as a central processing unit (CPU) or various computer processors, a storage device such as memory or storage, and wired or wireless communication lines connecting the arithmetic unit and the storage device. The software is stored in the storage device and configured to provide processing instructions to the arithmetic unit. The computer program may include a device driver, an operating system, various applications running above the device driver and operating system, or libraries that provide common functionality to these applications.

[0075] The controller 120 includes a program analysis unit 131, a position command unit 132, a motor control unit 133, and a position command correction unit 161.

[0076] The program analysis unit 131 reads the NC program (processor) stored in the storage unit 156, which will be described later. The program analysis unit 131 analyzes the NC program. The program analysis unit 131 extracts information related to the target movement position and movement speed of the movable object 30 from the NC program, and outputs the extracted information related to the target movement position and movement speed to the position command unit 132.

[0077] Based on the input information related to the target moving position and moving speed of the movable object 30, the position command unit 132 generates X-axis position command Px, Y-axis position command Py and Z-axis position command Pz in sequence according to the moving speed, and outputs the generated position commands Px, Py and Pz to the position command correction unit 161 and the motor control unit 133.

[0078] Motor control unit 133 controls servo motor 141. Motor control unit 133 generates a control signal (current control signal) based on a position command from position command unit 132, and controls servo motor 141 based on the generated control signal. More specifically, motor control unit 133 generates a control signal based on a position command Px from position command unit 132, and controls servo motor 141X based on the generated control signal. Motor control unit 133 generates a control signal based on a position command Py from position command unit 132, and controls servo motor 141Y based on the generated control signal. Motor control unit 133 generates a control signal based on a position command Pz from position command unit 132, and controls servo motor 141Z based on the generated control signal.

[0079] When thermal displacement occurs in the machine tool 100, the position command correction unit 161 corrects the position commands Px, Py, and Pz from the position command unit 132. After the position commands Px, Py, and Pz are corrected by the position command correction unit 161, the corrected position commands px, py, and pz are input to the motor control unit 133. The motor control unit 133 generates control signals based on the corrected position commands and controls the servo motor 141 based on the generated control signals.

[0080] The motor control unit 133 also performs feedback control on the servo motor 141 based on the position data of the movable object 30 detected by the linear scale 71. More specifically, the motor control unit 133 performs feedback control on the servo motor 141X based on the X-axis position data of the column 31 detected by the linear scale 71. The motor control unit 133 performs feedback control on the servo motor 141Y based on the Y-axis position data of the spindle head 22 detected by the linear scale 71. The motor control unit 133 performs feedback control on the servo motor 141Z based on the Z-axis position data of the worktable 41 detected by the linear scale 71.

[0081] The machine tool 100 includes linear guides 51X, 51Y and 51Z as linear guides 51.

[0082] The linear guide 51X guides the post 31 in the X-axis direction, and corresponds to... Figure 2 and Figure 3 The linear guide 51 is shown. Linear guide 51Y guides the spindle head 22 in the Y-axis direction. The guide rail 61 of linear guide 51Y is mounted on the column 31. The slider 65 of linear guide 51Y is mounted on the spindle head 22. Linear guide 51Z guides the worktable 41 in the Z-axis direction. The guide rail 61 of linear guide 51Z is mounted on the bed 12. The slider 65 of linear guide 51Z is mounted on the worktable 41.

[0083] The machine tool 100 includes temperature sensors 81X, 81Y and 81Z as temperature sensors 81.

[0084] Temperature sensor 81X is disposed in slider 65 of linear guide 51X, and corresponds to Figures 2 to 4Temperature sensor 81 is shown. Temperature sensor 81X detects the temperature Tx (hereinafter also referred to as "X-axis slider temperature Tx") of the slider 65 of linear guide 51X. Temperature sensor 81Y is disposed in the slider 65 of linear guide 51Y. Temperature sensor 81Y detects the temperature Ty (hereinafter also referred to as "Y-axis slider temperature Ty") of the slider 65 of linear guide 51Y. Temperature sensor 81Z is disposed in the slider 65 of linear guide 51Z. Temperature sensor 81Z detects the temperature Tz (hereinafter also referred to as "Z-axis slider temperature Tz") of the slider 65 of linear guide 51Z.

[0085] The machine tool 100 also includes a temperature sensor 82. For example, the temperature sensor 82 can be a thermistor. The temperature sensor 82 is located away from the temperature sensors 81 (81X, 81Y, 81Z). The temperature sensor 82 is mounted on the machine bed 12. The temperature sensor 82 is located near the factory floor or similar surface where the machine bed 12 is fixed. The temperature sensor 82 detects the body temperature t of the machine tool 100. The body temperature t is a reference temperature that depends on the ambient temperature (air temperature) of the machine tool 100.

[0086] Temperature sensors 81 (81X, 81Y, 81Z) generate signals indicating the detected temperatures of slider 65 (X-axis slider temperature Tx, Y-axis slider temperature Ty, Z-axis slider temperature Tz) and output these signals to controller 120. Temperature sensor 82 generates signals indicating the detected body temperature t of machine tool 100 and outputs these signals to controller 120.

[0087] The controller 120 also includes a temperature data acquisition unit 151. The temperature data acquisition unit 151 acquires temperature data including the temperature of the slider 65 detected by the temperature sensor 81 (X-axis slider temperature Tx, Y-axis slider temperature Ty, Z-axis slider temperature Tz) and the body temperature t of the machine tool 100 detected by the temperature sensor 82.

[0088] Temperature data acquisition unit 151 determines the X-axis slider temperature Tx based on the signal output from temperature sensor 81X. Temperature data acquisition unit 151 determines the Y-axis slider temperature Ty based on the signal output from temperature sensor 81Y. Temperature data acquisition unit 151 determines the Z-axis slider temperature Tz based on the signal output from temperature sensor 81Z. Temperature data acquisition unit 151 determines the machine body temperature t of machine tool 100 based on the signal output from temperature sensor 82. Temperature data acquisition unit 151 outputs the determined temperature data to position command correction unit 161.

[0089] Figure 6 It is shown Figure 5 A graph of the coefficient table in the document. (See reference.) Figure 5 and Figure 6The controller 120 also includes a storage unit 156. The storage unit 156 stores a coefficient table 157.

[0090] The position command correction unit 161 corrects the position commands Px, Py, and Pz based on the temperature of the slider 65 detected by the temperature sensor 81.

[0091] More specifically, the position command correction unit 161 includes a thermal displacement calculation component 162X, a thermal displacement calculation component 162Y, and a thermal displacement calculation component 162Z. The thermal displacement calculation component 162X calculates the thermal displacement Dx of the computer tool 100 along the X-axis. The thermal displacement calculation component 162Y calculates the thermal displacement Dy of the computer tool 100 along the Y-axis. The thermal displacement calculation component 162Z calculates the thermal displacement Dz of the computer tool 100 along the Z-axis.

[0092] The thermal displacement Dx calculated by thermal displacement calculation component 162X, the thermal displacement Dy calculated by thermal displacement calculation component 162Y, and the thermal displacement Dz calculated by thermal displacement calculation component 162Z are performed using the same method. As an example, the thermal displacement Dx calculated by thermal displacement calculation component 162X will be described.

[0093] The thermal displacement calculation component 162X reads the coefficient table 157 from the storage unit 156. Referring to the coefficient table 157, the thermal displacement calculation component 162X determines the coefficient Cxx to be applied to the X-axis position correction performed using the X-axis slider temperature Tx. The thermal displacement calculation component 162X calculates the thermal displacement dxx in the X-axis direction caused by the heat generated by the slider 65 of the linear guide 51X by substituting the X-axis slider temperature Tx, the machine body temperature t, and the coefficient Cxx into the equation (Tx-t)×Cxx. The thermal displacement dxx is primarily caused by heat generated by the slider 65 of the linear guide 51X as the column 31 moves in the X-axis direction, and transmitted via the guide rail 61 of the linear guide 51X to the bed 12 or the scale unit 72 of the linear scale 71 that detects the X-axis position of the column 31.

[0094] The thermal displacement calculation component 162X refers to coefficient table 157 to determine the coefficient Cyx to be applied to the X-axis position correction performed using the Y-axis slider temperature Ty. The thermal displacement calculation component 162X calculates the thermal displacement dyx in the X-axis direction caused by the heat generated by the slider 65 of the linear guide 51Y by substituting the Y-axis slider temperature Ty, the machine body temperature t, and the coefficient Cyx into the equation (Ty-t)×Cyx. The thermal displacement dyx is mainly caused by the heat generated by the slider 65 of the linear guide 51Y when the spindle head 22 moves in the Y-axis direction, and is transferred via the column 31 and the linear guide 51X to the bed 12 or the scale unit 72 of the linear scale 71 that detects the X-axis position of the column 31.

[0095] The thermal displacement calculation component 162X refers to the coefficient table 157 to determine the coefficient Czx to be applied to the X-axis position correction performed using the Z-axis slider temperature Tz. The thermal displacement calculation component 162X calculates the thermal displacement dzx in the X-axis direction caused by the heat generated by the slider 65 of the linear guide 51Z by substituting the Z-axis slider temperature Tz, the machine body temperature t, and the coefficient Czx into the equation (Tz-t)×Czx. The thermal displacement dzx is mainly caused by the heat generated by the slider 65 of the linear guide 51Z when the worktable 41 moves in the Z-axis direction, and is transferred via the guide rail 61 of the linear guide 51Z to the scale unit 72 of the linear scale 71 of the X-axis position of the bed 12 or the detection column 31.

[0096] The thermal displacement calculation component 162X calculates the thermal displacement Dx, which is the sum of thermal displacements dxx, dyx, and dzx (Dx = dxx + dyx + dzx).

[0097] Similarly, the thermal displacement calculation component 162Y uses the coefficient Cxy to calculate the thermal displacement dxy in the Y-axis direction caused by the heat generated by the slider 65 of the linear guide 51X, the coefficient Cyy to calculate the thermal displacement dyy in the Y-axis direction caused by the heat generated by the slider 65 of the linear guide 51Y, and the coefficient Czy to calculate the thermal displacement dzy in the Y-axis direction caused by the heat generated by the slider 65 of the linear guide 51Z. The thermal displacement calculation component 162Y calculates the thermal displacement Dy, which is the sum of the thermal displacements dxy, dyy, and dzy (Dy = dxy + dyy + dzy).

[0098] Furthermore, the thermal displacement calculation component 162Z uses coefficient Cxz to calculate the thermal displacement dxz in the Z-axis direction caused by the heat generated by the slider 65 of the linear guide 51X, uses coefficient Cyz to calculate the thermal displacement dyz in the Z-axis direction caused by the heat generated by the slider 65 of the linear guide 51Y, and uses coefficient Czz to calculate the thermal displacement dzz in the Z-axis direction caused by the heat generated by the slider 65 of the linear guide 51Z. The thermal displacement calculation component 162Z calculates the thermal displacement Dz, which is the sum of thermal displacement dxz, thermal displacement dyz, and thermal displacement dzz (Dz = dxz + dyz + dzz).

[0099] Figure 6The coefficient C shown was predetermined through experiments conducted by the manufacturer of machine tool 100. In the experiments, each movable object 30 (column 31, spindle head 22, worktable 41) reciprocated continuously, causing the slider 65, which guides the movable object 30 along the axial direction, to generate heat. Along with the heat generated by the slider 65, the temperature of the slider 65 and the temperature of the base of machine tool 100 were measured using temperature sensors, and the thermal displacement in the X-axis direction, Y-axis direction, and Z-axis direction at each temperature was measured using measuring instruments such as digital gauges. The coefficient C was determined by the relationship between the measured temperature and the measured thermal displacement.

[0100] like Figure 6 As shown, during X-axis position correction, slider 65 of linear guide 51X corresponds to the axial direction slider, and each slider 65 of linear guides 51Y and 51Z corresponds to the orthogonal axial direction slider. During Y-axis position correction, slider 65 of linear guide 51Y corresponds to the axial direction slider, and each slider 65 of linear guides 51X and 51Z corresponds to the orthogonal axial direction slider. During Z-axis position correction, slider 65 of linear guide 51Z corresponds to the axial direction slider, and each slider 65 of linear guides 51X and 51Y corresponds to the orthogonal axial direction slider.

[0101] like Figure 1 and Figure 6 As shown, the coefficient C applied to position correction performed using the axial slider temperature has a value that increases with the distance from the reference position in the axial direction, while the coefficient C applied to position correction performed using the orthogonal axial slider temperature has a constant value. Figure 6 In a machine tool 100 with machine specifications of 800 mm X-axis travel, 800 mm Y-axis travel, and 880 mm Z-axis travel, the coefficient C to be applied to position correction performed using the axial slider temperature is simply determined to be within a predetermined range for each axial direction.

[0102] For example, as coefficients Cxx to be applied to X-axis position correction performed using the X-axis slider temperature Tx, Cxx1 is determined to be in the range of 0 to -200 mm in the X-axis coordinate system; Cxx2, which is greater than Cxx1, is determined to be in the range of -200 mm to -400 mm in the X-axis coordinate system; Cxx3, which is greater than Cxx2, is determined to be in the range of -400 mm to -600 mm in the X-axis coordinate system; and Cxx4, which is greater than Cxx3, is determined to be in the range of -600 mm to -800 mm in the X-axis coordinate system. The thermal displacement calculation component 162X determines the coefficients Cxx within the range including the value of the position command Px by comparing the value of the position command Px with the coefficient table 157.

[0103] The coefficient C to be applied to the position correction performed using the temperature of the slider in the orthogonal axis direction can be determined in the same way as the coefficient C to be applied to the position correction performed using the temperature of the slider in the axial direction, within a predetermined range in each axial direction.

[0104] The position command correction unit 161 further includes a correction execution member 163. The correction execution member 163 corrects the position command Px based on the thermal displacement Dx calculated by the thermal displacement calculation member 162X. The correction execution member 163 corrects the position command Py based on the thermal displacement Dy calculated by the thermal displacement calculation member 162Y. The correction execution member 163 corrects the position command Pz based on the thermal displacement Dz calculated by the thermal displacement calculation member 162Z.

[0105] More specifically, the calibration execution member 163 calculates the calibration position command px by subtracting the thermal displacement Dx from the position command Px (px = Px - Dx). The calibration execution member 163 calculates the calibration position command py by subtracting the thermal displacement Dy from the position command Py (py = Py - Dy). The calibration execution member 163 calculates the calibration position command pz by subtracting the thermal displacement Dz from the position command Pz (pz = Pz - Dz). The calibration execution member 163 outputs the calculated calibration position commands Px, Py, and Pz to the servo motors 141 (141X, 141Y, 141Z).

[0106] Figure 7 This is a flowchart illustrating the control process of a servo motor. (Reference) Figures 5 to 7 In S110, when the machine tool 100 operates according to the NC program, temperature sensors 81X, 81Y and 81Z detect the X-axis slider temperature Tx, Y-axis slider temperature Ty and Z-axis slider temperature Tz respectively, and temperature sensor 82 detects the body temperature t of the machine tool 100.

[0107] Next, in S120, the controller 120 (temperature data acquisition unit 151) acquires the temperature data detected in step S110, including the X-axis slider temperature Tx, Y-axis slider temperature Ty, Z-axis slider temperature Tz, and body temperature t.

[0108] Next, in S130, controller 120 (thermal displacement calculation component 162X) refers to coefficient table 157 stored in storage unit 156 to determine coefficients Cxx, Cyx, and Czx. Similarly, controller 120 (thermal displacement calculation component 162Y) refers to coefficient table 157 stored in storage unit 156 to determine coefficients Cxy, Cyy, and Czy, and controller 120 (thermal displacement calculation component 162Z) refers to coefficient table 157 stored in storage unit 156 to determine coefficients Cxz, Cyz, and Czz.

[0109] Next, in S140, the controller 120 (thermal displacement calculation component 162X) uses the coefficient Cxx determined in step S130 and the X-axis slider temperature Tx and body temperature t obtained in step S120 to calculate the thermal displacement dxx, uses the coefficient Cyx determined in step S130 and the Y-axis slider temperature Ty and body temperature t obtained in step S120 to calculate the thermal displacement dyx, and uses the coefficient Cxz determined in step S130 and the Z-axis slider temperature Tz and body temperature t obtained in step S120 to calculate the thermal displacement dzx.

[0110] In the same manner, in S140, controller 120 (thermal displacement calculation component 162Y) calculates thermal displacement dxy, thermal displacement dyy and thermal displacement dzy, and controller 120 (thermal displacement calculation component 162Z) calculates thermal displacement dxz, thermal displacement dyz and thermal displacement dzz.

[0111] Next, in S150, controller 120 (thermal displacement calculation component 162X) uses the thermal displacements dxx, dyx, and dzx calculated in step S140 to calculate the thermal displacement Dx in the X-axis direction. In the same manner, controller 120 (thermal displacement calculation component 162Y) calculates the thermal displacement Dy in the Y-axis direction, and controller 120 (thermal displacement calculation component 162Z) calculates the thermal displacement Dz in the Z-axis direction.

[0112] Next, in S160, the controller 120 (correction execution member 163) uses the thermal displacement Dx calculated in step S150 to correct the position command Px from the position command unit 132 to the position command px. Similarly, the controller 120 (correction execution member 163) uses the thermal displacement Dy calculated in step S150 to correct the position command Py from the position command unit 132 to the position command py, and the controller 120 (correction execution member 163) uses the thermal displacement Dz calculated in step S150 to correct the position command Pz from the position command unit 132 to the position command pz.

[0113] Next, in S170, the controller 120 (motor control unit 133) controls the servo motors 141 (141X, 141Y, 141Z) according to the correction position commands px, py, pz.

[0114] The controller 120 repeats the above steps whenever a new target position for the movable object 30 is specified in the NC program.

[0115] Figure 8 This is a table showing the change of relative displacement along the X-axis over time during the reciprocating movement of the column in the first verification experiment. Figure 9 This is a table showing the change of relative displacement in the Y-axis direction over time during the reciprocating movement of the column in the second verification experiment.

[0116] refer to Figure 1 , Figure 8 and Figure 9 In both the first and second verification experiments, a machine tool 100 with a travel range of 800 mm for the X-axis, 800 mm for the Y-axis, and 880 mm for the Z-axis was used. The column 31 continuously reciprocated within the X-axis coordinate ranges of 0 to -200 mm, 0 to -400 mm, and 0 to -600 mm (feed rate F = 30000 mm / min, travel time = 8 h). The X-axis slider temperature (temperature of slider 65 of the linear guide 51X) increased by 1.9 °C from the start of the reciprocating motion upon completion of the reciprocating motion.

[0117] exist Figure 8 In the first verification experiment shown, the relative displacement in the X-axis direction between the cutting edge of the tool mounted on the spindle 21 and the worktable 41 was measured at each position with X-axis coordinates of -200mm, -400mm, and -600mm, and the change of relative displacement over time is shown in the figure. In the example where calibration was performed, the X-axis position command was calibrated using the axial slider temperature (the temperature of slider 65 of the linear guide 51X), and in the comparative example where no calibration was performed, the X-axis position command was not calibrated.

[0118] exist Figure 9 In the second verification experiment shown, the relative displacement in the Y-axis direction between the cutting edge of the tool mounted on the spindle 21 and the worktable 41 was measured at each position with X-axis coordinates of -200mm, -400mm, and -600mm, and the change of relative displacement over time is shown in the figure. In the example where calibration was performed, the orthogonal axis slider temperature (the temperature of slider 65 of the linear guide 51X) was used to calibrate the Y-axis position command, while in the comparative example where no calibration was performed, the Y-axis position command was not calibrated.

[0119] In both the first and second verification experiments, a position correction command was used to prevent relative displacement between the cutting edge of the tool mounted on the spindle 21 and the worktable 41.

[0120] To summarize the structure of the machine tool 100 according to the first embodiment of the present invention, the machine tool 100 according to this embodiment includes: a base 10; a movable object 30 movable relative to the base 10; a linear guide 51, which includes a guide rail 61 attached to the base 10 and a slider 65 attached to the movable object 30 and slidable along the guide rail 61, and is configured to guide the movable object 30 in the direction of movement of the movable object 30; and a temperature sensor 81 disposed in the slider 65 and configured to detect the temperature of the slider 65.

[0121] Furthermore, the machine tool 100 according to this embodiment includes: a movable object 30; a linear guide 51, which includes a guide rail 61 attached to the base 10 and a slider 65 attached to the movable object 30 and slidable along the guide rail 61, and is configured to guide the movable object 30 in the direction of movement of the movable object 30; and a temperature sensor 81 disposed in the slider 65 and configured to detect the temperature of the slider 65.

[0122] With this configuration, the temperature of the slider 65 detected by the temperature sensor 81 can be used to determine the thermal displacement caused by the heat generated by the slider 65, which is the heat source. Therefore, the influence of the thermal displacement caused by the heat generated by the slider 65 can be eliminated, which allows the movable object 30 to be positioned at the target moving position with higher accuracy.

[0123] The machine tool 100 also includes a servo motor 141 as a power source for moving the movable object 30 and a controller 120 that controls the servo motor 141 based on a position command indicating a target movement position of the movable object 30. The controller 120 corrects the position command based on the temperature of the slider 65 detected by the temperature sensor 81.

[0124] With this configuration, the effect of thermal displacement caused by the heat generated by the slider 65 can be eliminated by performing corrections by the controller 120. Therefore, the movable object 30 can be positioned to the target moving position with higher accuracy.

[0125] Furthermore, based on the temperature of the slider 65 of the linear guide 51X detected by temperature sensor 81X, the temperature of the slider 65 of the linear guide 51Y detected by temperature sensor 81Y, and the temperature of the slider 65 of the linear guide 51Z detected by temperature sensor 81Z, the controller 120 corrects the position command Px indicating the target movement position of the indicator post 31, corrects the position command Py indicating the target movement position of the spindle head 22, and corrects the position command Pz indicating the target movement position of the worktable 41.

[0126] This design eliminates not only the thermal effects generated by the axial slider but also those generated by the orthogonal axial slider. Therefore, the movable object 30 can be positioned to the target moving position with higher precision.

[0127] Furthermore, the temperature sensor 81 is supported by the resin component 67 of the slider 65 and is in contact with the body 66 of the slider 65. With this configuration, the temperature sensor 81 can be supported with a simple structure, and the temperature sensor 81 can be used to detect the temperature of the slider 65 more accurately.

[0128] The machine tool 100 according to this embodiment includes: a base 10; a movable object 30, which includes a slider 65 as a guide member guided by the base 10 and movable relative to the base 10; a temperature sensor 81 disposed in the slider 65 and configured to detect the temperature of the slider 65; a servo motor 141 serving as a power source for moving the movable object 30; and a controller 120 that controls the servo motor 141 based on a position command indicating a target movement position of the movable object 30. The controller 120 corrects the position command based on the temperature of the slider 65 detected by the temperature sensor 81.

[0129] With this configuration, the effect of thermal displacement caused by the heat generated by the slider 65 can be eliminated by performing corrections by the controller 120. Therefore, the movable object 30 can be positioned to the target moving position with higher accuracy.

[0130] The machine tool according to this embodiment includes: a movable object; a linear guide including a guide rail and a slider, the slider being attached to the movable object and slidable along the guide rail, and the linear guide being configured to guide the movable object in a direction of movement; and a temperature sensor disposed in the slider and configured to detect the temperature of the slider. When viewed in the sliding direction of the slider, the temperature sensor is located in the plane of the slider.

[0131] According to this configuration, the temperature of the slider detected by the temperature sensor can be used to determine the thermal displacement caused by the heat generated by the slider, which is the heat source. Therefore, the influence of thermal displacement caused by the heat generated by the slider can be eliminated, allowing for more accurate positioning of the movable object to the target movement position. Furthermore, when viewed along the sliding direction of the slider, the temperature sensor is located in the plane of the slider. In this configuration, since the temperature sensor is positioned in the space where the slider moves with its sliding operation, mounting space for the temperature sensor with respect to the slider can be easily secured, while avoiding interference between the temperature sensor and components surrounding the linear guide.

[0132] (Second Implementation)

[0133] Figure 10 This is a cross-sectional view showing a machine tool according to a second embodiment of the present invention. The machine tool 200 according to this embodiment has a structure substantially the same as that of the machine tool 100 according to the first embodiment. Descriptions of the same components will not be repeated below.

[0134] refer to Figure 10 In the machine tool 200 according to this embodiment, a sliding surface guiding system is used to guide the movable object 30 relative to the base 10. As an example, Figure 10 The cross-sections of the bed 12, which serves as the base 10, and the column 31, which serves as the movable object 30, are shown.

[0135] The bed 12 includes a sliding member 16. The column 31 includes a sliding member 32. The sliding members 16 and 32 face each other in the Y-axis direction. The sliding member 16 has a sliding surface 16a. The sliding surface 16a extends in a strip shape that is longer in the X-axis direction. The sliding member 32 has a sliding surface 32a. The sliding surface 32a is in surface contact with the sliding surface 16a via a lubricant. In this configuration, the sliding member 32 is guided by the bed 12 (sliding member 16) in the X-axis direction.

[0136] A temperature sensor 81 (81X) is disposed in the sliding member 32. The temperature sensor 81 (81X) is embedded in the sliding member 32. The temperature sensor 81 (81X) is embedded at a position in the Y-axis direction away from the sliding surface 32a. The distance between the temperature sensor 81 (81X) and the sliding surface 32a in the Y-axis direction can be 3 mm or less, 5 mm or less, 10 mm or less, or 30 mm or less. The temperature sensor 81 (81X) detects the temperature of the sliding member 32.

[0137] To summarize the structure of the machine tool 200 according to the second embodiment of the present invention, the machine tool 200 according to this embodiment includes: a base 10; a movable object 30 including a sliding member 32, which serves as a guide member guided by the base 10 and is movable relative to the base 10; a temperature sensor 81 disposed in the sliding member 32 and configured to detect the temperature of the sliding member 32; a servo motor 141 serving as a power source for moving the movable object 30; and a controller 120 controlling the servo motor 141 based on a position command indicating a target movement position of the movable object 30. The controller 120 corrects the position command based on the temperature of the sliding member 32 detected by the temperature sensor 81.

[0138] According to the machine tool 200 having the above-described structure in the second embodiment of the present invention, the same effects as those described in the first embodiment can be achieved.

[0139] (Third implementation method)

[0140] Figure 11 This is a perspective view showing the mounting position of a temperature sensor in the guide mechanism of a machine tool according to a third embodiment of the present invention, which differs from... Figure 2 The installation location. (See reference.) Figure 11 The temperature sensor 81 can be installed at any location that can detect the temperature of the slider 65.

[0141] Temperature sensor 81 can be mounted on the main body 66. Temperature sensor 81 can be mounted on the side surface of the main body 66 facing the X-axis direction, or it can be mounted on the side surface of the main body 66 facing the Z-axis direction. With this configuration, even if the distance between sliders 65J and 65K is small, sufficient mounting space for temperature sensor 81 can be ensured.

[0142] (Fourth Implementation)

[0143] The machine tool according to this embodiment has a structure that is substantially the same as that of the machine tool 100 according to the first embodiment. In the following text, descriptions of the same components will not be repeated.

[0144] Figure 12 This is a side view showing a machine tool according to a fourth embodiment of the present invention. Figure 13 It is shown Figure 12 The diagram shows the functional structure of the machine tool's control system. Figure 14 It is shown Figure 13 A graph of the coefficient table in the figure.

[0145] Reference Figures 12 to 14 The machine tool according to this embodiment includes a temperature sensor 81X and a temperature sensor 81Z, which are temperature sensors 81. Temperature sensor 81X is disposed in the slider 65 of the linear guide 51X and is configured to detect the X-axis slider temperature Tx. Temperature sensor 81Z is disposed in the slider 65 of the linear guide 51Z and is configured to detect the Z-axis slider temperature Tz.

[0146] Slider 65 has a mounting surface 211. An object guided by slider 65 is mounted on mounting surface 211. In slider 65 of linear guide 51X, post 31 is mounted on mounting surface 211. Mounting surface 211 is orthogonal to the Y-axis direction. In slider 65 of linear guide 51Z, table 41 is mounted on mounting surface 211. Mounting surface 211 is orthogonal to the Y-axis direction.

[0147] In this embodiment, the X-axis slider temperature Tx and the Z-axis slider temperature Tz are used as slider temperatures in the orthogonal axis direction to correct the position command indicating the target movement position of the spindle head 22 that can move in the Y-axis direction (i.e., to perform Y-axis position correction).

[0148] like Figure 13 and Figure 14 As shown, coefficient table 201 is stored in storage unit 156. Position command correction unit 161 includes thermal displacement calculation component 162Y. Thermal displacement calculation component 162Y calculates thermal displacement dxy and thermal displacement dzy in the Y-axis direction, which will be described below.

[0149] The thermal displacement calculation component 162Y reads the coefficient table 201 from the storage unit 156. The thermal displacement calculation component 162Y refers to the coefficient table 201 to determine the coefficient Sxy to be applied to the Y-axis position correction performed using the X-axis slider temperature Tx and the coefficient Szy to be applied to the Y-axis position correction performed using the Z-axis slider temperature Tz.

[0150] The thermal displacement calculation component 162Y calculates the thermal displacement dxy in the Y-axis direction caused by the heat generated by the slider 65 of the linear guide 51X by substituting the X-axis slider temperature Tx, the body temperature t, and the coefficient Sxy into the equation (Tx-t)×Sxy. The thermal displacement dxy is mainly caused by the following heat: this heat is generated by the slider 65 of the linear guide 51X when the column 31 moves in the X-axis direction and is transferred to the column 31 via the mounting surface 211 of the slider 65 of the linear guide 51X, thereby causing the column 31 to experience thermal expansion in the Y-axis direction orthogonal to the mounting surface 211 of the slider 65 of the linear guide 51X.

[0151] The thermal displacement calculation component 162Y calculates the thermal displacement dzy in the Y-axis direction caused by the heat generated by the slider 65 of the linear guide 51Z by substituting the Z-axis slider temperature Tz, the body temperature t, and the coefficient Szy into the equation (Tz-t)×Szy. The thermal displacement dzy is mainly caused by the heat generated by the slider 65 of the linear guide 51Z when the worktable 41 moves in the Z-axis direction, and is transferred to the worktable 41 via the mounting surface 211 of the slider 65 of the linear guide 51Z, so that the worktable 41 experiences thermal expansion in the Y-axis direction orthogonal to the mounting surface 211 of the slider 65 of the linear guide 51Z.

[0152] Figure 14 The coefficient S shown is predetermined through experiments conducted by the machine tool manufacturer.

[0153] In the experiment, column 31 reciprocates continuously in the X-axis direction, causing the slider 65 of the linear guide 51X of column 31 to generate heat. Along with the heat generated by slider 65, the temperature of slider 65 of linear guide 51X and the temperature of the machine tool 100 base are measured using a temperature sensor, and the thermal displacement of column 31 in the Y-axis direction at each temperature is measured using a measuring instrument such as a digital meter. The coefficient Sxy is determined by the relationship between the measured temperature and the measured thermal displacement. Furthermore, table 41 reciprocates continuously in the Z-axis direction, causing the slider 65 of linear guide 51Z of table 41 to generate heat. Along with the heat generated by slider 65, the temperature of slider 65 of linear guide 51Z and the temperature of the machine tool 100 base are measured using a temperature sensor, and the thermal displacement of table 41 in the Y-axis direction at each temperature is measured using a measuring instrument such as a digital meter. The coefficient Szy is determined by the relationship between the measured temperature and the measured thermal displacement.

[0154] The correction execution component 163 calculates the correction position command py (py=Py-dxy+dzy) based on the thermal displacement dxy and thermal displacement dzy.

[0155] like Figure 12 As indicated by arrow 310, due to heat from the slider 65 of the linear guide 51X, the column 31 thermally expands in the +Y axis direction, and the contact point of the tool T in the workpiece W shifts in the +Y axis direction. In this case, the correction direction of the spindle head 22 position command Py based on the thermal displacement dxy should be in the -Y axis direction. Figure 12 As indicated by arrow 320, due to the heat from the slider 65 of the linear guide 51Z, the worktable 41 thermally expands in the +Y axis direction, and the contact point of the tool T in the workpiece W shifts in the -Y axis direction. In this case, the correction direction of the spindle head 22 position command Py based on the thermal displacement dzy should be in the +Y axis direction.

[0156] The calibration execution component 163 outputs the calculated calibration position command py to the servo motor 141Y.

[0157] To summarize the structure of the machine tool according to the fourth embodiment of the present invention, the machine tool according to this embodiment includes: a movable object; a linear guide 51 (51X / 51Z) including a guide rail 61 and a slider 65, the slider 65 being attached to the movable object and slidable along the guide rail 61, and the linear guide being configured to guide the movable object in the direction of movement of the movable object; and a temperature sensor 81 (81X / 81Z) disposed in the slider 65 and configured to detect the temperature of the slider 65.

[0158] The movable object includes a first movable object (column 31 / table 41) movable in a first direction (X-axis / Z-axis direction). A slider 65 has a mounting surface 211 for mounting the first movable object (column 31 / table 41), and linear guides 51 (51X / 51Z) are configured to guide the first movable object (column 31 / table 41) in the first direction (X-axis / Z-axis direction). The movable object also includes a second movable object (spindle head 22) movable in a second direction (Y-axis direction) orthogonal to both the mounting surface 211 and the first direction (X-axis / Z-axis direction). The machine tool also includes: a servo motor 141Y, which serves as a power source for moving the second movable object (spindle head 22); and a controller 120 that controls the servo motor 141Y based on position commands indicating a target movement position of the second movable object (spindle head 22). The controller 120 corrects the position command indicating the target movement position of the second movable object (spindle head 22) based on the temperature of the slider 65 detected by the temperature sensors 81X / 81Z.

[0159] Furthermore, the machine tool according to this embodiment includes: a first movable object (column 31 / table 41) movable in a first direction (X-axis direction / Z-axis direction); a linear guide 51X / 51Z including a slider 65 having a mounting surface 211 for mounting the first movable object (column 31 / table 41), and the linear guide being configured to guide the first movable object (column 31 / table 41) in the first direction (X-axis direction / Z-axis direction); and a temperature sensor 81X / 8 A servo motor 141Y is disposed in the slider 65 and configured to detect the temperature of the slider 65; a second movable object (spindle head 22) movable in a second direction (Y-axis direction) orthogonal to both the mounting surface 211 and the first direction (X-axis direction / Z-axis direction); a servo motor 141Y serving as a power source for moving the second movable object (spindle head 22); and a controller 120 controlling the servo motor 141Y based on a position command indicating a target movement position of the second movable object (spindle head 22). The controller 120 corrects the position command indicating the target movement position of the second movable object (spindle head 22) based on the temperature of the slider 65 detected by the temperature sensors 81X / 81Z.

[0160] According to this configuration, even if the first movable object (pillar 31 / worktable 41) thermally expands in the second direction (Y-axis direction) due to the heat generated by the slider 65 that guides the first movable object (pillar 31 / worktable 41), the second movable object (spindle head 22) that can move in the second direction (Y-axis direction) can be positioned to the target movement position with higher accuracy by a position command based on the temperature correction indication of the slider 65.

[0161] (Fifth Implementation)

[0162] The machine tool according to this embodiment has a structure that is substantially the same as that of the machine tool 100 according to the first embodiment. In the following text, descriptions of the same components will not be repeated.

[0163] Figure 15 This is a side view showing a machine tool according to a fifth embodiment of the present invention. Figure 16 It is shown Figure 15 The diagram shows the functional structure of the machine tool's control system. Figure 17 It is shown Figure 16 A graph of the coefficient table in the figure.

[0164] Reference Figures 15 to 17 The machine tool according to this embodiment includes a temperature sensor 81Y, which serves as a temperature sensor 81. The temperature sensor 81Y is disposed in the slider 65 of the linear guide 51Y and is configured to detect the Y-axis slider temperature Ty. In the slider 65 of the linear guide 51Y, the spindle head 22 is mounted on a mounting surface 211. The mounting surface 211 is orthogonal to the Z-axis direction.

[0165] In this embodiment, the Y-axis slider temperature Ty is used as the orthogonal axis slider temperature to correct the position command that indicates the target movement position of the worktable 41 in the Z-axis direction (i.e., to perform Z-axis position correction).

[0166] like Figure 16 and Figure 17 As shown, coefficient table 202 is stored in storage unit 156. Position command correction unit 161 includes thermal displacement calculation component 162Z. Thermal displacement calculation component 162Z calculates the thermal displacement dyz in the Z-axis direction, which will be described below.

[0167] The thermal displacement calculation component 162Z reads the coefficient table 202 from the storage unit 156. The thermal displacement calculation component 162Z refers to the coefficient table 202 to determine the coefficient Syz to be applied to the Z-axis position correction performed using the Y-axis slider temperature Ty.

[0168] The thermal displacement calculation component 162Z calculates the thermal displacement dyz in the Z-axis direction caused by the heat generated by the slider 65 of the linear guide 51Y by substituting the Y-axis slider temperature Ty, the body temperature t, and the coefficient Syz into the equation (Ty-t)×Syz. The thermal displacement dyz is mainly caused by the heat generated by the slider 65 of the linear guide 51Y when the spindle head 22 moves in the Y-axis direction, and is transferred to the spindle head 22 via the mounting surface 211 of the slider 65 of the linear guide 51Y, thereby causing the spindle head 22 to experience thermal expansion in the Z-axis direction orthogonal to the mounting surface 211 of the slider 65 of the linear guide 51Y.

[0169] Figure 17 The coefficient S shown is predetermined through experiments performed by the machine tool manufacturer.

[0170] In the experiment, the spindle head 22 reciprocates continuously in the Y-axis direction, causing the slider 65 of the linear guide 51Y that guides the spindle head 22 to generate heat. Along with the heat generated by the slider 65, the temperature of the slider 65 of the linear guide 51Y and the temperature of the machine tool 100 base are measured using a temperature sensor, and the thermal displacement of the spindle head 22 in the Z-axis direction at each temperature is measured using a measuring instrument such as a digital meter. The coefficient Syz is determined by the relationship between the measured temperature and the measured thermal displacement.

[0171] The correction execution component 163 calculates the correction position command pz (pz=Pz+dyz) based on the thermal displacement dyz.

[0172] like Figure 15 As indicated by arrow 330, the spindle head 22 thermally expands in the +Z axis direction due to heat from the slider 65 of the linear guide 51Y, causing the contact point of the tool T in the workpiece W to shift in the +Z axis direction. In this case, the correction direction of the position command Pz of the table 41 based on the thermal displacement dyz should be in the +Z axis direction.

[0173] The calibration execution component 163 outputs the calibration position command pz to the servo motor 141Z.

[0174] To summarize the structure of the machine tool according to the fifth embodiment of the present invention, the machine tool according to this embodiment includes: a movable object; a linear guide 51 (51Y) including a guide rail 61 and a slider 65, the slider 65 being attached to the movable object and slidable along the guide rail 61, and the linear guide being configured to guide the movable object in the direction of movement of the movable object; and a temperature sensor 81 (81Y) disposed in the slider 65 and configured to detect the temperature of the slider 65.

[0175] The movable object includes a first movable object (spindle head 22) movable in a first direction (Y-axis direction). A slider 65 has a mounting surface 211 for mounting the first movable object (spindle head 22), and a linear guide 51 (51Y) is configured to guide the first movable object (spindle head 22) in the first direction (Y-axis direction). The movable object also includes a second movable object (table 41) movable in a second direction (Z-axis direction) orthogonal to both the mounting surface 211 and the first direction (Y-axis direction). The machine tool also includes a servo motor 141Z serving as a power source for moving the second movable object (table 41), and a controller 120 controlling the servo motor 141Z based on a position command indicating a target movement position of the second movable object (table 41). The controller 120 corrects the position command indicating the target movement position of the second movable object (table 41) based on the temperature of the slider 65 detected by a temperature sensor 81Y.

[0176] Furthermore, the machine tool according to this embodiment includes: a first movable object (spindle head 22) movable in a first direction (Y-axis direction); a linear guide 51Y including a slider 65 having a mounting surface 211 for mounting the first movable object (spindle head 22), and the linear guide being configured to guide the first movable object (spindle head 22) in the first direction (Y-axis direction); a temperature sensor 81Y disposed in the slider 65 and configured to detect the temperature of the slider 65; a second movable object (table 41) movable in a second direction (Z-axis direction) orthogonal to both the mounting surface 211 and the first direction (Y-axis direction); a servo motor 141Z serving as a power source for moving the second movable object (table 41); and a controller 120 controlling the servo motor 141Z based on a position command indicating a target movement position of the second movable object (table 41). The controller 120 corrects the position command indicating the target movement position of the second movable object (table 41) based on the temperature of the slider 65 detected by the temperature sensor 81Y.

[0177] According to this configuration, even if the first movable object (spindle head 22) thermally expands in the second direction (Z-axis direction) due to the heat generated by the slider 65 that guides the first movable object (spindle head 22), the second movable object (table 41) can be positioned to the target movement position with higher accuracy by a position command that indicates the target movement position of the second movable object (table 41) that can move in the second direction (Z-axis direction) based on the temperature correction of the slider 65.

[0178] (Sixth Implementation Method)

[0179] The machine tool according to the sixth embodiment combines the machine tool according to the fourth embodiment and the machine tool according to the fifth embodiment. In the following text, descriptions of the same components will not be repeated.

[0180] Figure 18 This is a side view showing a machine tool according to a sixth embodiment of the present invention. Figure 19 It is shown Figure 18 The diagram shows the functional structure of the machine tool's control system. Figure 20 It is shown Figure 19 A graph of the coefficient table in the figure.

[0181] Reference Figures 18 to 20 The machine tool according to this embodiment includes temperature sensor 81X, temperature sensor 81Y, and temperature sensor 81Z, which serve as temperature sensors 81. For example... Figure 19 and Figure 20 As shown, storage unit 256 stores coefficient table 203. Coefficient table 203 includes coefficient Sxy to be applied to Y-axis position correction performed using X-axis slider temperature Tx, coefficient Szy to be applied to Y-axis position correction performed using Z-axis slider temperature Tz, and coefficient Syz to be applied to Z-axis position correction performed using Y-axis slider temperature Ty.

[0182] In this embodiment, the X-axis slider temperature Tx and the Z-axis slider temperature Tz are used as orthogonal axis slider temperatures to correct position commands indicating the target movement position of the spindle head 22 that can move in the Y-axis direction (i.e., performing Y-axis position correction), which is the same as in the fourth embodiment. Furthermore, the Y-axis slider temperature Ty is used as the orthogonal axis slider temperature to correct position commands indicating the target movement position of the stage 41 that can move in the Z-axis direction (i.e., performing Z-axis position correction), which is the same as in the fifth embodiment.

[0183] With this construction, the same effects as in the fourth and fifth embodiments can be achieved.

[0184] The machine tool according to the present invention can be constructed by any combination of the machine tools described in the first to sixth embodiments.

[0185] It should be understood that the embodiments disclosed herein are illustrative in all respects and not restrictive. The scope of the invention is defined by the terminology of the claims rather than by the description of the embodiments above, and is intended to include any modifications within the scope and meaning of the terminology of the claims.

[0186] This application is based on Japanese Patent Application No. 2024-077845, filed on May 13, 2024, and Japanese Patent Application No. 2025-019345, filed on February 7, 2025, the entire contents of which are incorporated herein by reference.

[0187] [Explanation of reference numerals in the attached figures]

[0188] 10: Base; 12: Bed; 16, 32: Sliding components; 16a, 32a: Sliding surfaces; 21: Spindle; 22: Spindle head; 30: Movable object; 31: Column; 41: Worktable; 51, 51A, 51B, 51X, 51Y, 51Z: Linear guides; 61: Guide rail; 65, 65J, 65K: Slider; 66: Main body; 67, 67p, 67q: Resin components; 68: Hole; 71: Linear scale; 72: Scale unit; 73: Base component; 74: Scale body; 75: Cover; 76: Head unit; 81, 81X, 8 1Y, 81Z, 82: Temperature sensors; 100, 200: Machine tools; 101: Rotary axis; 120: Controller; 131: Program analysis unit; 132: Position command unit; 133: Motor control unit; 141, 141X, 141Y, 141Z: Servo motors; 151: Temperature data acquisition unit; 156: Storage unit; 157, 201, 202, 203: Coefficient tables; 161: Position command correction unit; 162X, 162Y, 162Z: Thermal displacement calculation component; 163: Correction execution component; 211: Mounting surface.

Claims

1. A machine tool, comprising: Movable objects; A linear guide includes a guide rail and a slider, the slider being attached to the movable object and capable of sliding along the guide rail, and the linear guide is configured to guide the movable object in the direction of movement of the movable object; as well as A temperature sensor is disposed in the slider and configured to detect the temperature of the slider.

2. The machine tool according to claim 1, wherein When viewed along the sliding direction of the slider, the temperature sensor is located in the plane of the slider.

3. The machine tool according to claim 1, wherein... The movable object includes a first movable object capable of moving in a first direction. The slider has a mounting surface for mounting the first movable object, and the linear guide is configured to guide the first movable object in the first direction. The movable object further includes a second movable object, which is capable of moving in a second direction orthogonal to both the mounting surface and the first direction. The machine tool also includes: A servo motor, which serves as a power source for moving the second movable object; as well as The controller controls the servo motor based on a position command indicating the target movement position of the second movable object. The controller calibrates the position command indicating the target movement position of the second movable object based on the temperature of the slider detected by the temperature sensor.

4. The machine tool according to claim 3, wherein The first movable object is a column or workbench capable of moving in the horizontal direction, and The second movable object is a spindle head that can move in the vertical direction.

5. The machine tool according to claim 3, wherein The first movable object is a spindle head capable of moving in the vertical direction, and The second movable object is a workbench that can move in the horizontal direction.

6. The machine tool according to claim 1 or 2, further comprising: A servo motor, which serves as a power source for moving the movable object; as well as The controller controls the servo motor based on position commands indicating the target movement position of the movable object. The controller calibrates the position command based on the temperature of the slider detected by the temperature sensor. The movable object includes a first movable object capable of moving in a first direction, a second movable object capable of moving in a second direction orthogonal to the first direction, and a third movable object capable of moving upward in a third direction orthogonal to both the first and second directions. The linear guide includes a first linear guide that guides the first movable object in the first direction, a second linear guide that guides the second movable object in the second direction, and a third linear guide that guides the third movable object in the third direction. The temperature sensor includes a first temperature sensor for detecting the temperature of the slider of the first linear guide, a second temperature sensor for detecting the temperature of the slider of the second linear guide, and a third temperature sensor for detecting the temperature of the slider of the third linear guide. The controller calibrates the position command indicating the target movement position of the first movable object based on the temperature of the slider of the first linear guide detected by the first temperature sensor, the temperature of the slider of the second linear guide detected by the second temperature sensor, and the temperature of the slider of the third linear guide detected by the third temperature sensor.

7. The machine tool according to claim 1 or 2, wherein The slider includes a body and a resin component. The body is made of metal and engages with the guide rail via a rolling element. The resin component is made of resin, disposed adjacent to and connected to the body in the direction of movement of the movable object. The temperature sensor is supported by the resin component and is in contact with the main body.

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