How to stabilize the processing quality of dental milling machines

Abstract

To stabilize processing quality of a dental milling machine even when the temperature and humidity of the dental milling machine changes.SOLUTION: A dental milling machine 10 includes a temperature sensor 91, preferably, further includes a humidity sensor 92. A control device 80 of the dental milling machine 10 records the temperature and humidity of the dental milling machine 10 when executing automatic correction of a relative positional relation between a clamp device 30 and a spindle unit 60 as a method of stabilizing the processing quality of the dental milling machine (step ST04). The method of stabilizing the processing quality of the dental milling machine determines whether or not a difference between the temperature and humidity before executing automatic correction or the current temperature and humidity before milling a workpiece 50 and the recorded temperature and humidity exceeds a prescribed threshold (steps ST05, ST08), and can execute the new automatic correction in order to update an automatic correction value (steps ST03, ST07).SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present invention relates to a method for stabilizing the processing quality of a dental processing machine (dental milling machine) that processes a workpiece into a prosthesis such as an artificial tooth (denture) by cutting it out. [Background technology]

[0002] A dental milling machine is disclosed in, for example, Patent Document 1, and the clamping device in Patent Document 1 can hold workpieces of different sizes. Dental milling machines are also disclosed in, for example, Patent Documents 2 and 3, and the dental milling machine in Patent Document 2 can store, for example, the origin of the XYZ coordinate system, the origin of the A-axis, the origin of the B-axis, and the origin of the S-axis, and can set, for example, the origin of the B-axis. Furthermore, according to Patent Document 3, the dental milling machine can automatically correct the relative positional relationship between the workpiece and the spindle unit, including the origin of the XYZ coordinate system. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-126456 [Patent Document 2] Japanese Patent Publication No. 2020-183006 [Patent Document 3] Japanese Patent Publication No. 2020-028935 Summary of the Invention [Problem to be solved by the invention]

[0004] When assembling a dental milling machine, the dental milling machine automatically corrects the relative positional relationship between the workpiece and the spindle unit to reduce assembly errors. Users also perform automatic correction when the relative positional relationship between the workpiece and the spindle unit is physically affected, such as when the dental milling machine is moved or parts are replaced. Users also perform automatic correction of the relative positional relationship between the workpiece and the spindle unit at any time, such as when a deterioration in processing quality, such as cutting, is observed. In addition to physical external factors such as changes in installation location and part replacement, automatic correction values ​​can change due to factors such as thermal expansion of parts due to temperature changes. However, users have been unable to detect these changes, and therefore changes in processing accuracy (e.g., the origin of the XYZ coordinate system) or deterioration in processing quality.

[0005] One object of the present invention is to provide a method for stabilizing the processing quality of a dental milling machine even when the temperature and humidity of the dental milling machine change. Other objects of the present invention will become apparent to those skilled in the art by referring to the following exemplary aspects and best modes, as well as the accompanying drawings. [Means for solving the problem]

[0006] In order to facilitate an understanding of the outline of the present invention, the following examples are given of embodiments according to the present invention.

[0007] In an embodiment according to the present invention, a method for stabilizing the processing quality of a dental milling machine equipped with a temperature sensor and / or a humidity sensor includes: performing automatic correction of a relative positional relationship between a clamping device and a spindle unit of the dental milling machine; recording the temperature and / or humidity detected by the temperature sensor and / or humidity sensor after performing the automatic correction; Includes.

[0008] According to an embodiment of the present invention, the temperature and / or humidity, preferably both the temperature and humidity, after automatic correction is performed are recorded. The inventors discovered that there is a good correlation between the automatic correction value and temperature and humidity, and by monitoring changes in temperature and humidity, it is possible to manage changes in the automatic correction value (processing accuracy). Furthermore, since automatic correction can be performed at an appropriate timing, it is possible to obtain stable processing quality.

[0009] Those skilled in the art will easily understand that the exemplified embodiments according to the present invention can be further modified without departing from the spirit of the present invention. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a perspective view of a dental milling machine according to the present invention; [Figure 2] FIG. 2 is a perspective view of the clamping device shown in FIG. 1. [Figure 3] 10 is a plan view of the rotation device and the rotation support member, showing a state in which a clamp device is attached to the rotation support member. FIG. [Figure 4] FIG. [Figure 5] FIG. 2 is a schematic diagram showing a detection tool and a processing tool. [Figure 6] FIG. 2 is a block diagram of a control system for the dental milling machine shown in FIG. 1. [Figure 7] 2 is a flowchart for implementing a method for stabilizing the processing quality of the dental milling machine shown in FIG. 1. [Figure 8] FIG. 8(A) is a graph showing the change over time in the automatically corrected value and the temperature, and FIG. 8(B) is a graph showing the correlation between the automatically corrected value and the temperature. [Figure 9] FIG. 9(A) is a graph showing the change over time in the automatically corrected value and humidity, and FIG. 9(B) is a graph showing the correlation between the automatically corrected value and humidity. DETAILED DESCRIPTION OF THE INVENTION

[0011] The best mode described below with reference to the accompanying drawings is used to facilitate understanding of the present invention. Therefore, those skilled in the art should note that the present invention is not unduly limited by the embodiments described below. In the accompanying drawings, Fr indicates front, Rr indicates rear, Le indicates left, Ri indicates right, Up indicates top, and Dn indicates bottom. The dental milling machine 10 is arranged in an XYZ coordinate system with three mutually intersecting axes: X-axis, Y-axis, and Z-axis.

[0012] Referring to Figure 1, a dental milling machine 10 equipped with a control device 80 is used to machine dental prostheses (artificial teeth). Inside a milling machine body 11 serving as a housing, the dental milling machine 10 is equipped with a rotation device 13 that rotatably supports a workpiece 50, a clamping device 30 that is fixed to the rotation device 13 and holds the workpiece 50, and a spindle unit 60 that cuts the workpiece 50. The spindle unit 60, to which a processing tool 6A is attached, is mounted on a carriage 38.

[0013] The X-axis extends in the front-rear direction, the Y-axis extends in the left-right direction, and the Z-axis extends in the up-down direction. In the example of FIG. 1, the X-axis extends in the same direction as the horizontal direction, and the Z-axis extends in the same direction as the vertical direction. The rotation axis (S-axis) of the processing tool 6A is arranged parallel to the Z-axis. The processing tool 6A and the spindle unit 60 can move in the X-axis and Z-axis directions via a carriage 38. The workpiece 50, the clamping device 30, and the rotation device 13 can move in the Y-axis direction via a movement mechanism 58.

[0014] The workpiece 50, clamping device 30, and rotating device 13 can rotate around the B-axis by any rotation angle θB. The workpiece 50 and clamping device 30 can rotate around the A-axis by any rotation angle θA. In the example of FIG. 1, the rotation axis 46 (B-axis) of the rotating device 13 is arranged parallel to the Y-axis, and the rotation axis (A-axis) of the clamping device 30 is arranged parallel to the X-axis. The dental milling machine 10 can control the relative positional relationship between the workpiece 50 and the machining tool 6A, for example, along the X-axis, Y-axis, Z-axis, A-axis, and B-axis, using a conventionally known method; a detailed description of the structure or mechanism of the dental milling machine 10 is omitted here.

[0015] Unlike conventional milling machines, dental milling machine 10 in Fig. 1 is equipped with temperature sensor 91 and humidity sensor 92. Temperature sensor 91 and humidity sensor 92 can record the temperature and humidity in order to detect changes in the temperature and humidity of dental milling machine 10, for example, at the timing when the origin of the XYZ coordinate system is automatically corrected.

[0016] Note that dental milling machine 10 may be provided with only temperature sensor 91 of temperature sensor 91 and humidity sensor 92, and record only the temperature of dental milling machine 10 during automatic correction. Alternatively, dental milling machine 10 may be provided with only humidity sensor 92 of temperature sensor 91 and humidity sensor 92, and record only the humidity of dental milling machine 10 during automatic correction.

[0017] 1, as in conventional milling machines, a milling machine cover 11a is attached to a milling machine body 11 so as to be slidable, for example, in the vertical direction. When milling a workpiece 50 with a machining tool 6A, the milling machine cover 11a is lowered.

[0018] The dental milling machine 10 according to the present invention is not limited to the example of FIG. 1, and like a conventional milling machine, it can be provided with, for example, a tool magazine (not shown) capable of accommodating the processing tool 6A.

[0019] See Fig. 2. The clamping device 30 has, for example, a support part 40 on which the workpiece 50 is placed, a plate-shaped clamping plate 32 that clamps the workpiece 50 together with the support part 40, and a fastening member 33 that fastens the support part 40 and the clamping plate 32 together. As with conventional clamping devices, the clamping device 30 is capable of replacing the workpiece 50. The workpiece 50 is made of, for example, a disk-shaped plaster, and a plurality of artificial teeth (not shown) can be carved out of the workpiece 50.

[0020] Please refer to Figure 3. More specifically, the rotation device 13 includes a rotation holding member 70 that detachably holds the clamp device 30, and the rotation holding member 70 is movable in the X-axis direction by the movement of the movement mechanism 58 (see Figure 1) in the X-axis direction.

[0021] Please refer to Fig. 4. The detection jig 20 is used, for example, when automatically correcting the origin of an XYZ coordinate system. In Fig. 4, the detection jig 20 is equipped with an adapter such as a clamping device 30, and the user can hold or install the detection jig 20 on a rotating holding member 70 (rotating device 13) instead of the workpiece 50.

[0022] Similar to conventional detection jigs, the detection jig 20 includes, for example, a detection member, which may be, for example, a first rod member 24A. In FIG. 4, the detection jig 20 has, for example, one first through hole 23A and two second through holes 23B formed through the planar portion 21. The first through hole 23A is an elongated hole extending in the X-axis direction. The second through hole 23B is an elongated hole extending in the Y-axis direction. The detection jig 20 includes the first rod member 24A extending in the Y-axis direction and disposed in the first through hole 23A, and the second rod member 24B extending in the X-axis direction and disposed in the second through hole 23B.

[0023] Referring to FIG. 5, a processing tool 6A is used to cut a workpiece 50. The processing tool 6A has a gripped portion 7A that is supported by a spindle unit 60, similar to conventional processing tools. In FIG. 5, a flange 7C is provided on the processing tool 6A. A blade portion 7B is provided below the flange 7C. The blade portion 7B of the rotating processing tool 6A comes into contact with the workpiece 50, thereby cutting the workpiece 50. The processing tool 6A is generally formed so that the diameter DT of the blade portion 7B is smaller than the gripped portion 7A. The length LT from the flange 7C to the lower end (tip) of the blade portion 7B when the processing tool 6A is gripped by the spindle unit 60 depends on the type of processing tool 6A. The processing tool 6A is formed of a conductive material such as metal.

[0024] When correcting the position of the dental milling machine 10, the detection tool 6B is used instead of the processing tool 6A. Correcting the position of the dental milling machine 10 means correcting the relative positional relationship between the spindle unit 60 and the rotation device 13 (holding member), and is performed by a conventionally known method.

[0025] In FIG. 5, the detection tool 6B is provided with a flange 9C, similar to conventional detection tools. The gripped portion 9A of the detection tool 6B is gripped by a gripping portion of the spindle unit 60. A detection portion 9B is provided below the flange 9C. The detection portion 9B of the detection tool 6B contacts the detection member of the detection jig 20. The detection tool 6B is formed, for example, so that the diameter DX of the detection portion 9B is constant. The diameter DX of the detection portion 9B is larger than the diameter DT of the blade portion 7B of the processing tool 6A. When the detection tool 6B is gripped by the spindle unit 60, the length LX from the flange 9C to the lower end (tip) of the detection portion 9B is usually longer than the length LT from the flange 7C to the lower end (tip) of the blade portion 7B of the processing tool 6A. In the example shown in FIG. 5, the length LX of the detection tool 6B is the same as the length LT of the processing tool 6A. The detection tool 6B is made of a conductive material such as metal.

[0026] Please refer to Fig. 6. Dental milling machine 10 has a configuration similar to that of conventional milling machines and a new configuration not included in conventional milling machines, and control device 80 of Fig. 6 also has a configuration similar to that of conventional control devices and a new configuration not included in conventional control devices.

[0027] (conventional control method) First, a conventional control method for controlling the relative positional relationship between the workpiece 50 (or detection member) and the processing tool 6A (or detection tool 6B) along, for example, the X-axis, Y-axis, Z-axis, A-axis, and B-axis will be described.

[0028] As shown in FIG. 6, the overall operation of the dental milling machine 10 is controlled by a control device 80. The configuration of the control device 80 is not particularly limited. The control device 80 is, for example, a microcomputer. The hardware configuration of the microcomputer is not particularly limited, but it may include, for example, an interface (I / F) that receives processing data and the like from an external device such as a host computer, a central processing unit (CPU) that executes instructions of a control program, a read only memory (ROM) that stores the program executed by the CPU, a random access memory (RAM) used as a working area for expanding the program, and a storage device such as a memory that stores the program and various data. As shown in FIG. 1, the control device 80 is provided, for example, inside the milling machine main body 11 (casing main body).

[0029] 6, the control device 80 is communicatively connected to and controls the rotating unit 63, the first driving mechanism 38C, the second driving mechanism 38D, the first motor 59D, the second motor 47, and the third motor 55. The control device 80 controls the movement of the spindle unit 60 (or the detection tool 6B) in the Z-axis direction and the Y-axis direction, the rotation of the processing tool 6A about the S-axis by θS, and the movement and rotation of the rotation device 13 (holding member) (i.e., the movement of the rotary holding member 70 in the X-axis direction, the rotation of the rotary holding member 70 about the B-axis by θB, and the rotation of the clamp device 30 about the A-axis by θA).

[0030] The rotating part 63 is a rotating part of the spindle unit 60, and like a conventional spindle unit, the spindle unit 60 includes, for example, a cylindrical main body, the rotating part 63 provided on the main body, and a gripping part provided at the lower end of the rotating part 63 for gripping the processing tool 6A and the detection tool 6B. The rotating part 63 rotates around the S-axis θS relative to the main body of the spindle unit 60, causing the processing tool 6A to rotate around the S-axis θS. The rotating part 63 is controlled by a control device 80.

[0031] The first drive mechanism 38C can move the carriage 38 in the Y-axis direction. The second drive mechanism 38D can move the carriage 38 in the Z-axis direction. Like conventional carriages, the carriage 38 includes, for example, a first carriage supported by a first guide shaft extending in the left-right direction and a second carriage supported by a second guide shaft extending in the up-down direction. The carriage 38 is provided to be movable in the Z-axis direction and the Y-axis direction. In other words, the carriage 38 moves the spindle unit 60 mounted on the carriage 38 in the Z-axis direction and the Y-axis direction. For example, the carriage 38 (first carriage) carrying the spindle unit 60 (processing tool 6A or detection tool 6B) can be moved in the Y-axis direction along the first guide shaft by the first drive mechanism 38C. The carriage 38 (second carriage) carrying the spindle unit 60 (processing tool 6A or detection tool 6B) can be moved in the Z-axis direction along the second guide shaft by the second drive mechanism 38D. The first drive mechanism 38C and the second drive mechanism 38D are controlled by a control device 80.

[0032] The first motor 59D is provided in the moving mechanism 58, which is similar to a conventional moving mechanism and includes, for example, the first motor 59D and a third guide shaft extending in the X-axis direction. The holding member (rotating holding member 70) of the rotating device 13 that holds the workpiece 50 (or the detection member of the detection jig 20) can be moved in the X-axis direction along the third guide shaft by driving the first motor 59D. The first motor 59D is controlled by the control device 80.

[0033] The second motor 47 rotates the rotation shaft 46 of the rotation device 13 around the B axis by θB. In other words, the rotation device 13 is provided with a rotation shaft 46 that rotatably supports the rotation device 13. The rotation shaft 46 extends in the Y axis direction. The second motor 47 is controlled by the control device 80. When the second motor 47 is driven, the rotation shaft 46 of the rotation device 13 rotates around the B axis by θB. Then, as the rotation shaft 46 rotates, the workpiece 50 (or the detection member of the detection jig 20) held by the holding member (rotating holding member 70) of the rotation device 13 rotates around the B axis by θB.

[0034] The third motor 55 rotates the rotary holding member 70 of the rotation device 13 by an angle θA around the A-axis. In other words, the rotary holding member 70 is rotatably supported by the rotation device 13. The third motor 55 is controlled by the control device 80. When the third motor 47 is driven, the rotary holding member 70 of the rotation device 13 rotates by an angle θA around the A-axis. Then, as the rotary holding member 70 rotates, the workpiece 50 (or the detection member of the detection jig 20) held by the rotary holding member 70 rotates by an angle θA around the A-axis.

[0035] As shown in Fig. 6, the control device 80 includes a storage unit 81, a processing control unit 82, and an automatic correction unit 83. The functions of each unit of the control device 80 are realized by a program. This program is read from a recording medium such as a CD or DVD. Note that this program may also be downloaded via the Internet.

[0036] The storage unit 81 stores, for example, the origin of the XYZ coordinate system, the origin of the A axis, the origin of the B axis, and the origin of the S axis.

[0037] The control device 80, like a conventional control device, includes a machining control unit 82 for cutting the workpiece 50 based on machining data. The automatic correction unit 83 will be briefly described below.

[0038] The machining data are, for example, coordinate values ​​indicated in commands of a machining program, and the machining control unit 62 controls the operation of the spindle unit 60 and the rotation device 13. The machining control unit 62 changes the relative positional relationship between the workpiece 50 and the machining tool 6A in three dimensions to achieve high-precision machining through five-axis control in the X-axis direction, Y-axis direction, Z-axis direction, θA around the A-axis, and θB around the B-axis. The cutting tool portion 7B of the machining tool 6A, rotated by the rotation unit 63 of the spindle unit 60, is brought into contact with the workpiece 50 held by the rotation device 13, thereby machining the workpiece 50.

[0039] Furthermore, like conventional control devices, the control device 80 includes an automatic correction unit 83 that automatically corrects, for example, the origin of the XYZ coordinate system, etc. The automatic correction unit 83 will be briefly described below.

[0040] The user can automatically correct the relative positional relationship between the workpiece 50 and the spindle unit 60 by, for example, selecting or clicking an automatic correction button (not shown). Specifically, the user holds the detection jig 20 on the rotary holding member 70 (rotation device 13) instead of the workpiece 50, and holds the detection tool 6B on the spindle unit 60 instead of the processing tool 6A, and selects or operates the automatic correction button. In response to this, the instruction unit 15 can execute or start the automatic correction unit 83.

[0041] The automatic correction unit 83 controls the operation of the spindle unit 60 and the rotation device 13, for example, based on coordinate values ​​indicated in commands of the automatic correction program. The automatic correction unit 83 acquires the coordinates at which the detection unit 9B of the detection tool 6B and the detection member of the detection jig 20 come into contact (are electrically conductive), and can determine an automatic correction value (offset amount) for the origin of the XYZ coordinate system, for example, from the deviation between the coordinates (acquired position) and a known ideal position, and store the value in the memory unit 81, for example.

[0042] (New control method) Next, a novel control method for detecting changes in temperature and humidity of dental milling machine 10 will be described.

[0043] 6, the control device 80 includes a management unit 84 that manages predetermined thresholds for detecting changes in temperature and humidity, and the management unit 84 can monitor the temperature detected by a temperature sensor 91 and the humidity detected by a humidity sensor 92. The management unit 84 can also record the temperature and humidity of the dental milling machine 10 as necessary.

[0044] As shown in FIG. 6, the control device 80 includes a stabilization unit 85 that stabilizes the automatic correction value determined by the automatic correction unit 83.

[0045] The stabilization unit 85 determines whether the difference between the stored temperature and humidity and the current temperature and humidity exceeds a predetermined threshold, and if this difference exceeds the predetermined threshold, automatically activates the automatic correction unit 83 to determine a new automatic correction value and update the automatic correction value. Furthermore, the stabilization unit 85 evaluates the automatic correction value determined by the automatic correction unit 83, and if the automatic correction value is not reliable, the stabilization unit 85 can discard the determined automatic correction value and automatically repeat the determination of the automatic correction value until a reliable automatic correction value is obtained.

[0046] The management unit 84 can notify the user via the notification unit 16 that automatic correction will be automatically performed when a change in temperature and humidity is detected.

[0047] See Figure 7. As an example, while dental milling machine 10 is powered on, controller 80 can continue to implement a method for stabilizing the processing quality of the dental milling machine.

[0048] As shown in step ST01, for example, the stabilization unit 85 can determine whether the automatic correction unit 83 has been manually started based on an instruction from a user. The stabilization unit 85 can monitor the execution state of the automatic correction unit 83, and before the automatic correction unit 83 is manually started and performs automatic correction (first time), can cause the management unit 84 to record the temperature and humidity at the time immediately before the automatic correction is performed (step ST02).

[0049] The automatic correction unit 83 executes the automatic correction (step ST03), and the stabilization unit 85 can cause the management unit 84 to record the temperature and humidity at the time immediately after the execution of the automatic correction (first time) (step ST04). The stabilization unit 85 can determine whether there is a difference in temperature and humidity that exceeds a predetermined threshold value before and after the automatic correction (first time) (step ST05).

[0050] If there is a difference in temperature and humidity that exceeds a predetermined threshold before and after the (first) automatic correction, the stabilization unit 85 determines that the (first) automatic correction value is unreliable, and can notify the user by displaying on the notification unit 16, such as a display, that the automatic correction (second time) will be automatically performed again (step ST06). The stabilization unit 85 automatically performs the next (second) automatic correction by the automatic correction unit 83 (step ST03), and can record the temperature and humidity at the time immediately after the (second) automatic correction is performed in the management unit 84 (step ST04).

[0051] The stabilization unit 85 can treat the temperature and humidity at the time immediately after the first automatic correction is performed as the temperature and humidity at the time immediately before the second automatic correction is performed, and can determine whether there was a difference in temperature and humidity that exceeded a predetermined threshold before and after the second automatic correction (step ST05).

[0052] Although step ST03 is executed after step ST06 is executed, step ST02 may be executed after step ST06 is executed, and the temperature and humidity may be recorded at a time that is later than the time immediately after the automatic correction (first time) is executed and immediately before the automatic correction (second time) is executed.

[0053] The stabilization unit 85 evaluates the automatic correction value determined by the automatic correction unit 83, and if the automatic correction value is not reliable, the stabilization unit 85 discards the determined automatic correction value and automatically repeats the determination of the automatic correction value until a reliable automatic correction value is obtained (step ST06 and step ST03).

[0054] For example, if a reliable automatic correction value is obtained by the automatic correction (first time), the stabilization unit 85 can associate the temperature and humidity at the time immediately after the automatic correction (first time) is performed with the automatic correction value (first time), and can cause, for example, the management unit 84 to manage and record the automatic correction value (first time) (step ST07).

[0055] Similarly, if a reliable automatic correction value is obtained by, for example, the second automatic correction, the stabilization unit 85 can associate the temperature and humidity at the time immediately after the second automatic correction is performed with the second automatic correction value, and can cause, for example, the management unit 84 to manage and record only the second automatic correction value (step ST07).

[0056] The stabilization unit 85 can determine whether the difference between the temperature and humidity associated with the automatic correction value managed by the management unit 84 and the current temperature and humidity exceeds a predetermined threshold (step ST08). The stabilization unit 85 can periodically, for example at predetermined intervals, determine whether the automatic correction value managed by the management unit 84 is a reliable automatic correction value even at the current temperature and humidity.

[0057] For example, even if a reliable automatic correction value is obtained by the automatic correction (first time), if a change in temperature and humidity occurs in the dental milling machine 10 thereafter and the temperature and humidity difference exceeds a predetermined threshold, the stabilization unit 85 determines that the automatic correction value (first time) is unreliable and can notify the user by displaying on the notification unit 16, such as a display, that automatic correction (second time) will be automatically performed again (step ST09).

[0058] Similarly, even if a reliable automatic correction value is obtained by automatic correction (second time), if a change in temperature and humidity occurs in the dental milling machine 10 thereafter and the temperature and humidity difference exceeds a predetermined threshold, the stabilization unit 85 determines that the automatic correction value (second time) is unreliable and can notify the user by displaying on the notification unit 16, such as a display, that automatic correction (third time) will be automatically performed again (step ST09).

[0059] When a change in temperature or humidity occurs in the dental milling machine 10, the stabilization unit 85 executes automatic correction (step ST03) and can update the automatic correction value (step ST07).

[0060] (Variation) 7 may be modified and executed, for example, as follows: For example, the stabilization unit 85 may monitor the execution state of the machining control unit 82, and may determine whether the automatic correction value managed by the management unit 84 is a reliable automatic correction value even at the current temperature and humidity (immediately before machining) before cutting the workpiece 50 based on the machining data.

[0061] If the automatic correction value is not reliable, the stabilization unit 85 can prompt the user to perform automatic correction. For example, the stabilization unit 85 can notify the user by displaying a message on the notification unit 16, such as a display, that the automatic correction should be performed manually.

[0062] Step ST07 in FIG. 7 may be modified and executed, for example, as follows. It is sufficient for the management unit 84 to manage only one automatic correction value (offset amount) used when the machining control unit 82 is running. However, past automatic correction values ​​(automatic correction values ​​that have been discarded or cleared) may also be managed and recorded as log data (step ST07). When the management unit 84 manages and records multiple automatic correction values, the user can obtain, for example, the graphs shown in FIGS. 8(A) and 8(B) and 9(A) and 9(B). The log data may be managed by the storage unit 81 or may be managed externally to the dental milling machine 10, for example, on a cloud server (not shown).

[0063] As shown in FIG. 8A, the control device 80 can record, for example, 700 reliable offset amounts of the origin of the Y coordinate (e.g., automatic correction values ​​[μm] relative to the normalized Y coordinate origin of 0 [μm]) in association with the temperature at the time of automatic correction. Referring to FIG. 8A, as a non-limiting example, when the environmental temperature of the dental milling machine 10 (e.g., the air temperature at the location where the dental milling machine 10 is installed), indicated by the dashed-dotted line, varies within a range of, for example, 2.5°C to 20°C, the Y coordinate origin (machining accuracy in the Y-axis direction), indicated by the thick solid line, varies within a range of -30 μm to +40 μm. To prevent changes in machining accuracy or deterioration in machining quality, an appropriate threshold value (temperature) can be set.

[0064] As a non-limiting example, the data in FIG. 8(A) showed a good correlation (for example, a correlation coefficient of 0.61) between the automatically corrected value and the temperature at the time of automatic correction, as shown in FIG. 8(B).

[0065] As shown in FIG. 9A, the control device 80 can record, for example, 700 reliable offset amounts of the origin of the Y coordinate (e.g., automatic correction values ​​[μm] relative to the normalized Y coordinate origin of 0 [μm]) in association with the humidity at the time of automatic correction. Referring to FIG. 9A, as a non-limiting example, when the environmental humidity of the dental milling machine 10 (e.g., the humidity of the location where the dental milling machine 10 is installed), indicated by the dashed-dotted line, varies within a range of, for example, 20% to 80%, the Y coordinate origin (machining accuracy in the Y-axis direction), indicated by the thick solid line, varies within a range of -30 μm to +40 μm. To prevent changes in machining accuracy or deterioration in machining quality, an appropriate threshold value (temperature) can be set.

[0066] As another example, and not limited to this, the data in FIG. 9(A) had a good correlation (for example, a correlation coefficient of 0.79) between the automatically corrected value and the humidity at the time of automatic correction, as shown in FIG. 9(B).

[0067] The present invention is not limited to the above-described exemplary embodiments, and those skilled in the art will be able to easily modify the above-described exemplary embodiments to the extent that they fall within the scope of the claims. [Explanation of symbols]

[0068] 10 Dental milling machine, 11 Milling machine body, 11a Milling machine cover body, 13 Rotation device, 15 Indicator, 16 Notification unit, 20 Jig device, 21 Flat portion, 23A, 23B Through holes, 24A, 24B Rod member, 30 Clamping device, 32 Clamp plate, 33 Fastening member, 38 Carriage, 38C Carriage, 38D Drive mechanism, 40···Instruction unit, 46···Rotation unit, 47···Second motor, 50···Workpiece, 55···Third motor, 58···Movement mechanism, 59D···First motor, 60···Spindle unit, 63···Rotation unit, 70···Rotation holding member, 80···Control device, 81···Memory unit, 82···Processing control unit, 83···Automatic correction unit, 84···Management unit, 85···Stabilization unit, 91···Temperature sensor, 92···Humidity sensor.

Claims

1. A method for stabilizing the processing quality of a dental milling machine, comprising: The dental milling machine includes a temperature sensor and a humidity sensor, and the method includes: performing automatic correction of a relative positional relationship between a clamping device and a spindle unit of the dental milling machine; recording the temperature and humidity detected by the temperature sensor and humidity sensor after performing the automatic correction; A method comprising:

2. recording the temperature and humidity detected by the temperature sensor and humidity sensor before performing the automatic correction; The method of claim 1 further comprising:

3. A step of recording the temperature and humidity detected by the temperature sensor and humidity sensor before cutting the workpiece. The method of claim 1 or 2 further comprising:

4. the step of recording the temperature and the humidity detected by the temperature sensor and the humidity sensor after the automatic correction is performed includes recording the automatic correction values ​​determined by the automatic correction in association with the temperature and the humidity; The method of claim 1.

5. A method for stabilizing the processing quality of a dental milling machine, comprising: The dental milling machine includes a temperature sensor and / or a humidity sensor, and the method further comprises: performing automatic correction of a relative positional relationship between a clamping device and a spindle unit of the dental milling machine; recording the temperature and / or humidity detected by the temperature sensor and / or humidity sensor after performing the automatic correction; Including, The step of recording the temperature and / or humidity detected by the temperature sensor and / or humidity sensor after the automatic correction is performed includes recording the automatic correction value determined by performing the automatic correction in association with the temperature and / or humidity; (i) the difference between the temperature and humidity detected by the temperature sensor and humidity sensor before the automatic correction is performed, or the temperature and humidity detected by the temperature sensor and humidity sensor before cutting the workpiece, and (ii) the difference between the temperature and humidity detected by the temperature sensor and humidity sensor after the automatic correction is performed and recorded in association with the determined automatic correction value, a step of determining whether a predetermined threshold is exceeded; The method further comprises:

6. performing a new automatic correction if the difference exceeds the predetermined threshold. The method of claim 5 further comprising:

7. a step of notifying a user of the execution of the new automatic correction; The method of claim 6 further comprising:

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