How to calculate tool correction

Abstract

To provide a correction calculation method for a processing tool that can correcting the position of a tool edge with a reduced influence of mechanical secular change of a machine tool.SOLUTION: A device body portion of a probe measurement device is held on chuck means 46 of a machine tool by chucking, and a measurement is performed by bringing a processing tool 44 (44a, 44b, 44c) of the machine tool into contact with a probe part 12 of a probe measurement device 4 at a plurality of angular positions defined by rotating the chuck means 46 in the circumferential direction. A correction value for the processing tool 44 is computed using measurement values for the probe measurement device 4 at the plurality of angular positions. Measurement is preferably performed by bringing the processing tool of the machine tool into contact with the probe part of the probe measurement device at a plurality of angle positions defined by rotating the chuck means at intervals of a prescribed angle (for example, 90 degrees) in the circumferential direction.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a machining tool correction calculation method for correcting the position of the cutting edge of a machining tool attached to a machining device. [Background technology]

[0002] Various types of tool presetters have been proposed for correcting the position of the cutting edge of a machining tool, and a representative one is a tool presetter for CNC lathes sold by Metrol Co., Ltd. (see Non-Patent Document 1). This tool presetter for CNC lathes (for example, the H series) has a cubic setter body, and measuring units are provided on four side surfaces of this setter body, and each measuring unit is provided with a measurement contact unit. When using this tool presetter, a support arm is attached to the lathe body of a machine tool (for example, a CNC lathe), and the tool presetter is attached to the tip of this support arm.

[0003] When correcting the position of the tool tip of a machining tool attached to a machine tool in the Z-axis direction (axis direction of the spindle), the machining tool is moved in the Z-axis direction and the tool tip is brought into contact with the measurement contact part of the first predetermined measurement part (Z-axis direction measurement part) of the tool presetter, the difference between the feed amount of the machine tool in the Z-axis direction and the measurement value of the tool presetter is calculated, and this calculated value becomes the correction value in the Z-axis direction of the machining tool attached to the machine tool. When correcting the position of the tool tip of the machining tool in the X-axis direction (or Y-axis direction), i.e., the front-back direction perpendicular to the axis of the spindle (or the up-down direction perpendicular to the axis of the spindle), the machining tool is moved in the X-axis direction (or Y-axis direction) and the tool tip is brought into contact with the measurement contact part of the second predetermined measurement part of the tool presetter, i.e., the measurement part of the X-axis direction (or Y-axis direction), the difference between the feed amount of the machine tool in the X-axis direction (or Y-axis direction) and the measurement value of the tool presetter is calculated, and this calculated value becomes the correction value in the X-axis direction (or Y-axis direction) of the machining tool attached to the machine tool. [Prior art documents] [Non-patent literature]

[0004] [Non-Patent Document 1] Tool presetter for CNC lathes in the product lineup on Metrol Co., Ltd.'s website (https: / / www.metrol.co.jp / products / tool-setter_h / ) Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the above-mentioned tool presetter, since the setter body is attached to the support arm attached to the machine tool, depending on the type and model of the machine tool, a part of the support arm and / or the tool presetter may be positioned in the movement path of the machining tool and interfere with it, and the positional relationship between the machining tool and the workpiece cannot be measured. In addition, such a configuration in which the tool is attached to the support arm causes mechanical deterioration over time and the support arm to which the tool presetter is attached may be displaced over time. In addition, a detachable tool presetter has a problem that the attachment may vary, making it impossible to set the machining tool accurately.

[0006] An object of the present invention is to provide a method for calculating corrections for a machining tool, which is capable of correcting the position of the tool tip while minimizing the effects of mechanical changes over time in the machine tool. [Means for solving the problem]

[0007] The present invention provides a method for calculating a correction value for a machining tool, comprising the steps of: chucking a main body of a probe measuring device to a chuck means of a machine tool; Three or more angular positions at equal angular intervals around the entire circumference of the A machining tool of the machine tool is brought into contact with a probe portion of the probe measuring device to perform measurement, 3 or more Measurement value of the probe measuring device in angular position Calculate the average value of The present invention is characterized in that a correction value for the machining tool is calculated.

[0008] A method for calculating the correction for such a machining tool Now, the entire circumference of the chuck meansIt is preferable to rotate the probe at 90 degree intervals in the circumferential direction to four angular positions, at which a machining tool of the machine tool is brought into contact with the probe portion of the probe measuring device and measurements are taken. Effect of the Invention

[0009] According to the method for calculating the correction for a machining tool of the present invention, the main body of the probe measuring device is chucked and held by the chuck means of the machine tool. At equal angular intervals around the circumference Rotated 3 or more angle positions The measurement is performed by bringing the machining tool of the machine tool into contact with the probe part of the probe measuring device. 3 or more Probe measuring device for angular position Calculate the average of the measured values ​​and based on the average Since a correction value for the machining tool is calculated, the correction value includes the amount of mechanical displacement over time of the machine tool, including the spindle and chuck means, and furthermore, there is no variation when installing the probe measuring device. As a result, the position of the tool tip of the machining tool can be corrected with high precision. [Brief description of the drawings]

[0010] [Figure 1] 1 is a perspective view showing an embodiment of a tool presetter for implementing a correction calculation method for a machining tool according to the present invention; [Diagram 2] FIG. 2 is a cross-sectional view showing a state in which the tool presetter of FIG. 1 is held by a chuck means of a machine tool. [Diagram 3] FIG. 3 is an end view taken along line III-III in FIG. 2. [Figure 4] 2 is a simplified cross-sectional view showing a state when the tool presetter of FIG. 1 is used to perform correction in the X-axis direction (outer diameter machining) of a machining tool. FIG. [Diagram 5] 11 is a cross-sectional view showing a state in which the machining tool moves in the X-axis direction (outer diameter machining) and comes into contact with a contact member of the tool presetter and oscillates. FIG. [Figure 6] FIG. 2 is a simplified cross-sectional view showing a state in which the tool presetter of FIG. 1 is used to perform correction in the Z-axis direction of a machining tool. [Figure 7] 13 is a cross-sectional view showing a state in which the machining tool moves in the Z-axis direction and comes into contact with a contact member of the tool presetter and oscillates. FIG. [Figure 8] 2 is a simplified cross-sectional view showing a state when the tool presetter of FIG. 1 is used to perform correction in the X-axis direction (internal diameter machining) of a machining tool. FIG. [Figure 9] 11 is a cross-sectional view showing a state in which the machining tool moves in the X-axis direction (internal diameter machining) and comes into contact with a contact member of the tool presetter and oscillates. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, an embodiment of a tool presetter for carrying out a machining tool correction calculation method according to the present invention will be described with reference to the accompanying drawings. In Fig. 1 and Fig. 2, the illustrated tool presetter 2 includes a probe measuring device 4, a support member 6 attached to the probe measuring device 4, and a contact member 8 supported by the support member 6 so as to be able to swing freely. The probe measuring device 4 includes a device main body 10 having a cylindrical outer shape, and a probe portion 12 extending from the device main body 10, and the probe portion 12 is attached so as to be able to swing freely in any direction, as will be understood from the following description.

[0012] Although not shown, a contact signal generating circuit that generates a contact signal, a transmission circuit that transmits the generated contact signal, and the like are built into the device main body 10. A tip contact part 14 is provided at one end (tip) of the probe part 12, and when the probe part 12 comes into contact with the tip contact part 14 and swings, a contact signal is generated and transmitted.

[0013] The support member 6 includes a support body 18 having a hollow space 16, a tip wall 20 is provided at one axial end side (tip side) of the support body 18, a support receiving portion 22 is provided at the tip wall 20, and the inner peripheral surface of the support receiving portion 22 is formed into a spherical shape. A base end wall 24 is provided at the other end side 8 (base end side) of the support body 18, and the base end wall 24 is attached to the device body 10 of the probe measurement device 4. A through opening 26 is provided at the center of the base end wall 24 of the support member 6, and the tip side of the probe portion 12 of the probe measurement device 4 extends into the hollow space 16 of the support member 6 through the through opening 26 of the base end wall 24.

[0014] Furthermore, the contact member 8 is cylindrical and has a spherical portion 32 provided in the axial middle portion, which is supported by the support receiving portion 22 of the support member 6 so as to be swingable in any direction. One end side (tip side) of the contact member 8 protrudes outward from the tip of the support member 6, and a measurement contact portion 34 is provided at this protruding end portion. The measurement contact portion 34 is formed in a ring shape, and a circular recess 36 is provided on its tip surface.

[0015] Furthermore, the other end side (base side) of the contact member 8 extends toward the probe measurement device 4, and a casing recess 38 extending axially from the base end is provided at the base end 37, and the tip end (a portion including the tip contact portion 14) of the probe portion 12 of the probe measurement device 4 is inserted into this casing recess 38. In this embodiment, the opening of the casing recess 38 is enlarged in diameter to prevent a portion other than the tip contact portion 14 of the probe portion 12 from contacting the casing recess 38 of the contact member 8 (specifically, its inner peripheral surface).

[0016] In this embodiment, the contact member 8 is configured such that the weight of one end side (tip side) and the weight of the other end side (base end side) are almost equally balanced with the center of the spherical portion 32 in the middle part as a fulcrum. Therefore, as can be seen from Fig. 2, the contact member 8 swings smoothly and stably with the spherical portion 32 as a fulcrum, and it is possible to accurately detect that a processing tool 44 (44a to 44c) (for example, a cutting processing tool) has come into contact with the contact member 8.

[0017] In this embodiment, the other end side (base side) of the contact member 8 is configured to be concentrically positioned in the hollow space 16 inside the support member 6 as follows. Referring also to Fig. 3, a ring-shaped outer permanent magnet 40 is attached to the inner peripheral surface of the support body 18 of the support member, and a ring-shaped inner permanent magnet 42 is attached to the outer peripheral surface of the base end portion 37 (other end) of the contact member 8, facing radially from the outer permanent magnet 40. As shown in Fig. 3, the inner peripheral portion of the outer permanent magnet 40 and the outer peripheral portion of the inner permanent magnet 42 are configured to face radially with the same magnetic pole (for example, N pole).

[0018] Specifically, the outer permanent magnet 40 is magnetized in the radial direction, and four portions (i.e., four portions at 90 degree intervals) at its inner circumferential portion in the radial direction that are substantially equally spaced in the circumferential direction are magnetized to the N pole as shown in Fig. 3, and the inner permanent magnet 42 is also magnetized in the radial direction, and four portions (i.e., four portions at 90 degree intervals) at its outer circumferential portion in the radial direction are magnetized to the N pole as shown in Fig. 3, and by configuring in this manner, the N pole of the inner circumferential portion of the outer permanent magnet 40 and the N pole of the outer circumferential portion of the inner permanent magnet 42 face each other in the radial direction. Therefore, a magnetic repulsive action is generated over substantially the entire circumference of the inner circumferential portion of the outer permanent magnet 40 and the outer circumferential portion of the inner permanent magnet 42, and due to this magnetic repulsive action, when the machining tool 44 is not acting on the contact member 8, the other end side (base side) of the contact member 8 is held concentrically on the radially inner side of the support body 18 of the support member 6 as shown in Figs. 2 and 3.

[0019] In this embodiment, four circumferential portions are magnetized, however, the number of magnetized portions may be any appropriate number, for example, six or eight circumferential portions that are substantially equally spaced apart may be magnetized.

[0020] This tool presetter 2 is attached to, for example, a chuck means 46 of a CNC lathe as an example of a machine tool. When, for example, a four-jaw chuck is used as the chuck means 46, the chuck means 46 has four chuck jaw members 48 (only two of which are shown in FIG. 2) arranged at intervals in the circumferential direction, and the device body 10 of the tool presetter 2 is chucked and held between these four chuck jaw members 48. Although not shown, it is also possible to use a three-jaw chuck as the chuck means, and in this case, the chuck means has three chuck jaw members arranged at intervals in the circumferential direction, and the device body 10 of the tool presetter 2 is chucked and held between these three chuck jaw members.

[0021] The position correction of the machining tools 44 (44a to 44c) by the tool presetter 2 is performed, for example, as follows. For example, when performing outer diameter machining of a workpiece, when correcting the position of the machining tools in the X-axis direction of a machine tool 62, the tool presetter 2 (specifically, the device main body 10 of the probe measuring device 4) is attached to the chuck means 46 of the machine tool 62 (for example, a CNC lathe) as shown in Fig. 2. Then, the position correction in the X-axis direction during outer diameter machining by the machining tool 44a is performed as shown in Figs. 2, 4 and 5.

[0022] The machining tool 44a is positioned radially (in the X-axis direction) outside the measurement contact portion 34 of the contact member 8 as shown by the dashed line 44a in Fig. 2, and the tool mounting table 64 is moved from this position in the X-axis direction (see Fig. 4) to bring the tool blade tip 50a of the machining tool 44a into contact with the outer circumferential surface of the measurement contact portion 34. When the tool blade tip 50a moves in the direction shown by the arrow 66 and comes into contact with the measurement contact portion 34, as shown in Fig. 5, the measurement contact portion 34 of the contact member 8 moves downward with the spherical portion 32 as a fulcrum and rotates slightly in the clockwise direction in Fig. 5, whereby the base end portion 37 moves upward in Fig. 5.

[0023] In this way, the accommodating recess 38 (the inner circumferential surface defining this accommodating recess 38) of the base end 37 of the contact member 8 comes into contact with the tip contact portion 14 of the probe portion 12 of the probe measurement device 4, the moving contact of the machining tool 44a is transmitted to the probe portion 12 of the probe measurement device 4 via the contact member 8, and the contact position of the probe measurement device 4 with the probe portion 12 can be accurately measured, and this contact position becomes the measurement value of the probe measurement device 4 in the X-axis direction.

[0024] Regarding position correction in the X-axis direction of the machining tool 44a, in this embodiment, the contact position of the machining tool 44a with the measurement contact portion 34 of the contact member 8 is measured by the probe measuring device 4 in the same manner as described above at four angular positions obtained by rotating the chuck means 46 at 90 degree intervals in the circumferential direction. Then, the measurement values ​​of the probe measuring device 4 at these four angular positions are calculated to calculate an average value, and the calculated average measurement value becomes the measurement value by the probe measuring device 4. Using this average measurement value, a correction value (in the X-axis direction) of the machining tool 44a is calculated in the same manner as in the conventional method, and when actually machining the workpiece, the position of the machining tool 44a in the X-axis direction is corrected with this correction value.

[0025] This correction value (X-axis direction) of the machining tool 44a is calculated using the average value of the measured values ​​of four angular positions in the circumferential direction of the chuck means 46 when the tool presetter 2 is held by the chuck means 46 of the machine tool 62, so it also takes into account the amount of mechanical displacement over time of the machine tool 62 including the spindle (not shown) and the chuck means 46. Therefore, by using such a correction value, the position of the tool tip 50a of the machining tool 44a can be corrected with high precision when machining the outer diameter.

[0026] When performing position correction of the machining tool 44 in the Z-axis direction of the machine tool 62, such as when machining the end face of a workpiece, the tool presetter 2 is attached to the chuck means 46 of the machine tool 62 (e.g., a CNC lathe) as shown in Fig. 2. Then, position correction in the Z-axis direction when machining, for example, the end face with the machining tool 44 is performed as shown in Figs. 2, 6 and 7.

[0027] The machining tool 44 is positioned outside the measurement contact portion 34 of the contact member 8 in the Z-axis direction as shown by the dashed line 44b in Fig. 2, and the tool mounting table 64 is moved from this position in the Z-axis direction (see Fig. 6) to bring the tool blade tip 50b of the machining tool 44b into contact with the tip surface of the measurement contact portion 34. When the tool blade tip 50b moves in the direction shown by the arrow 72 and contacts the measurement contact portion 34, as shown in Fig. 7, the measurement contact portion 34 of the contact member 8 moves upward with the spherical portion 32 as a fulcrum and rotates slightly counterclockwise in Fig. 7, whereby the base end portion 37 moves downward in Fig. 7.

[0028] In this way, the accommodating recess 38 of the base end 37 of the contact member 8 comes into contact with the tip contact portion 14 of the probe portion 12 of the probe measuring device 4, the moving contact of the machining tool 44b is transmitted to the probe portion 12 of the probe measuring device 4 via the contact member 8, and this contact position becomes the measurement value in the Z-axis direction of the probe measuring device 4.

[0029] As for the position correction in the Z-axis direction of the machining tool 44b, in the same manner as in the X-axis direction, the chuck means 46 is rotated at 90° intervals in the circumferential direction to obtain four angular positions, and the contact position of the machining tool 44b with the measurement contact portion 34 of the contact member 8 is measured by the probe measuring device 4 in the same manner as described above. Then, the measurement values ​​of the probe measuring device 4 at these four angular positions are calculated to calculate an average value, and the calculated average measurement value becomes the measurement value in the Z-axis direction by the probe measuring device 4. Using this average measurement value, a correction value (in the Z-axis direction) of the machining tool 44b is calculated in the same manner as in the conventional method, and when actually machining, for example, an end face of the workpiece, the position in the Z-axis direction of the machining tool 44a is corrected by using this correction value.

[0030] This correction value (Z-axis direction) of the machining tool 44b is calculated using the average value of the measured values ​​of four angular positions in the circumferential direction of the chuck means 46 when the tool presetter 2 is held by the chuck means 46 of the machine tool 62. Therefore, it also takes into account the amount of mechanical displacement over time of the machine tool 62, including the spindle (not shown) and the chuck means 46, and therefore, for example, when machining an end face, the position of the tool tip 50b of the machining tool 44b can be corrected with high precision.

[0031] When performing position correction of the machining tool 44 in the X-axis direction of the machine tool 62 in the case of machining the inner diameter of a workpiece, the tool presetter 2 is attached to the chuck means 46 of the machine tool 62 (e.g., a CNC lathe) as shown in Fig. 2. Then, position correction in the X-axis direction when machining the inner diameter with the machining tool 44 is performed as shown in Figs. 2, 8 and 9.

[0032] The machining tool 44 (in this case, an inner diameter machining tool is used instead of an outer diameter machining tool, but for ease of understanding, the same reference numerals "44" or "44c" are used) is positioned inside the measurement contact portion 34 of the contact member 8 in the Z-axis direction (inside the ring-shaped measurement contact portion 34) as shown by the dashed line 44c in Fig. 2, and the tool mounting table 64 is moved from this position in the X-axis direction (see Fig. 8) to bring the tool blade tip 50c of the machining tool 44c into contact with the inner peripheral surface of the measurement contact portion 34. When the tool blade tip 50c moves in the direction shown by the arrow 82 and contacts the inner peripheral surface of the circular recess 36 of the measurement contact portion 34, as shown in Fig. 9, the measurement contact portion 34 of the contact member 8 moves upward with the spherical portion 32 as a fulcrum and rotates somewhat counterclockwise in Fig. 9, whereby the base end portion 37 moves downward in Fig. 9.

[0033] In this way, similar to the movement in the Z-axis direction described above, the accommodating recess 38 of the base end 37 of the contact member 8 comes into contact with the tip contact portion 14 of the probe portion 12 of the probe measuring device 4, the moving contact of the machining tool 44b is transmitted to the probe portion 12 of the probe measuring device 4 via the contact member 8, and this contact position becomes the measurement value in the X-axis direction of the probe measuring device 4.

[0034] For position correction of the machining tool 44b in the X-axis direction (inner diameter machining), the chuck means 46 is rotated at 90° intervals in the circumferential direction to four angular positions, and the average value of the measurements of the probe measuring device 4 at the four angular positions is calculated, and the calculated average measurement value becomes the measurement value in the X-axis direction (inner diameter machining) by the probe measuring device 4, in the same manner as in the case of the X-axis direction (outer diameter machining). Then, using this average measurement value, a correction value (X-axis direction) of the machining tool 44c is calculated in the same manner as in the conventional method, and when the workpiece is actually machined in the inner diameter, the position of the machining tool 44c in the X-axis direction is corrected with this correction value. This correction value also takes into consideration the amount of mechanical displacement over time of the machine tool 62 including the shaft (not shown) and the chuck means 46, and for example, the position of the tool tip 50b of the machining tool 44b can be corrected with high accuracy when machining the inner diameter.

[0035] Although the method for calculating corrections for a machining tool according to the present invention has been described above, the present invention is not limited to such an embodiment, and various modifications and changes are possible without departing from the scope of the present invention.

[0036] For example, in the above-described embodiment, the measurement contact portion 34 of the contact member 8 is formed in a ring shape, but is not limited to such a shape and may be formed, for example, in a solid cylindrical shape. When a solid cylindrical contact member is used, it can be applied to position correction in outer diameter machining and position correction in end face machining.

[0037] Also, for example, in the above-described embodiment, the permanent magnets 40 on the support member 6 side and the permanent magnets 42 on the contact member 8 are held concentrically by utilizing the magnetic repulsion between them, but instead of such a configuration, they may be held concentrically by a mechanical holding structure (for example, a holding structure using multiple springs).

[0038] Also, for example, in the above-described embodiment, measurements are taken by the probe measuring device 4 at four locations around the circumference of the chuck means 46 (four angular positions spaced apart around the circumference), but the number is not limited to this and may be fewer than four, for example, three locations, or more than four, for example, six or eight locations.

[0039] In addition, in the above-described embodiment, a correction calculation method for a machining tool was explained using the tool presetter 2 shown in Figures 1 to 9, but this correction calculation method can also be applied when a tool presetter of a different form from this tool presetter 2 is used.

[0040] Furthermore, this machining tool compensation calculation method can also be applied when the probe measuring device 4 used in the tool presetter 2 is used instead of the tool presetter 2. In this case, even if the device body 10 of the probe measuring device 4 is chucked and held by the chuck means 46 of the machine tool and the machining tool 44 of the machine tool is brought into contact with the probe portion 12 of the probe measuring device 4 at multiple angular positions obtained by rotating the chuck means 46 in the circumferential direction, it is possible to calculate the compensation value of the machining tool 44 using multiple measurement values ​​of the probe measuring device 4 in the same manner as described above. [Explanation of symbols]

[0041] 2 Tool Presetter 4. Probe measuring device 6 Supporting member 8 Contact member 10. Device main body 12 Probe section 14 Tip contact part 32 Spherical part 34 Measuring contacts 40 outer permanent magnet 42 Inner permanent magnet 44,44a,44b,44c processing tools 46 Chuck means 50a,50b,50c Tool cutting edge 62 Machine tools

Claims

1. a main body of a probe measuring device is chucked and held on a chuck means of a machine tool, and the chuck means is rotated circumferentially at equal angular intervals around the entire circumference of the chuck means to bring a machining tool of the machine tool into contact with a probe portion of the probe measuring device at three or more angular positions to take measurements, an average value of measurement values ​​of the probe measuring device at the three or more angular positions is calculated, and a correction value for the machining tool is calculated based on the calculated average value.

2. 2. The method for calculating corrections for a machining tool according to claim 1, characterized in that the machining tool of the machine tool is brought into contact with the probe portion of the probe measuring device at four angular positions obtained by rotating the entire circumference of the chuck means in a circumferential direction at 90 degree intervals, and measurements are performed.

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