Processing machine and method for manufacturing workpiece

Abstract

To provide a processing machine which can acquire information of a position which serves as a reference when a workpiece and a tool are moved relative to each other.SOLUTION: In a processing machine 1, a Z axis electric motor 39 moves a spindle 37 in a Z direction. A Z axis position sensor 69 detects a position of the spindle 37 in the Z direction. A rotation sensor 71 detects rotation of the spindle 37. A control unit 5 controls the Z axis electric motor 39 based on a detection value of the Z axis position sensor 69 so that the spindle 37 is moved to a relative position set relative to a predetermined reference position in the Z direction when a workpiece 103 is processed with a tool 101 in a state that the spindle 37 rotates. The control unit 5 acquires the position, which is detected by the Z axis position sensor 69 when a predetermined signal is input in a state that rotation of the spindle 37 is detected by the rotation sensor 71 and the spindle 37 is moved in the Z direction to place the tool 101 in contact with a reference member in the Z direction, as a the reference position.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present disclosure relates to a processing machine and a method for manufacturing a workpiece. [Background technology]

[0002] There are known processing machines that use a tool to process (e.g., cut) a workpiece (see, for example, Patent Documents 1 and 2 below). Patent Documents 1 and 2 disclose a cutting device (processing machine) that uses a blade (tool) with a cutting edge on its outer periphery to divide a wafer (workpiece). Such processing machines achieve a desired cutting depth, for example, by moving the blade to a set relative position with respect to a predetermined reference position.

[0003] The position information that serves as the reference position is obtained, for example, by bringing the blade close to the workpiece or the table that holds the workpiece and detecting the position of the blade when contact between the two is detected. The background art sections of Patent Documents 1 and 2 disclose a technology in which conductive materials are used as the blade and table, and contact between the two is detected by utilizing the current that flows when the two come into contact.

[0004] Contact between the blade and the table can cause problems such as deterioration of one of them. Patent Document 1 proposes a technique in which a high-frequency voltage is applied to the blade and the table, and the proximity of the two is detected based on a change in the capacitance between them. Patent Document 2 proposes a technique in which, instead of the blade, a pseudo-blade that imitates the blade is used to obtain information on the reference position. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 61-071967 [Patent Document 2] Japanese Patent Application Laid-Open No. 2015-103693 Summary of the Invention [Problem to be solved by the invention]

[0006] The technology of Patent Document 1 requires the use of a conductive blade. This means that the freedom of blade selection is reduced. The technology of Patent Document 2 requires a pseudo-blade in addition to the blade. Furthermore, errors may occur due to differences between the blade and the pseudo-blade. Therefore, there is a need for a processing machine and a method for manufacturing a workpiece that can obtain information on a suitable reference position. [Means for solving the problem]

[0007] A machining center according to one aspect of the present disclosure includes a spindle that holds one of a tool and a workpiece, a holding unit that holds the other of the tool and the workpiece, a drive unit that moves one of the movable units, that is, the spindle or the holding unit, in a predetermined first direction, a position sensor that detects the position of the movable unit in the first direction, a rotation sensor that detects the rotation of the spindle, and a control unit that controls the drive unit based on the detection value of the position sensor so as to move the movable unit in the first direction to a relative position set with respect to a predetermined reference position when the workpiece is machined with the tool while the spindle is rotating.When the workpiece or a member that is immovable with respect to the workpiece is referred to as a reference member, the control unit acquires as the reference position the position detected by the position sensor when a predetermined signal is input, while the rotation of the spindle is detected by the rotation sensor and the movable unit moves in the first direction so that the tool and the reference member are in contact in the first direction.

[0008] A method for manufacturing a workpiece according to one aspect of the present disclosure uses the above-described processing machine to process the workpiece with the tool to obtain the workpiece.

[0009] A method for manufacturing a workpiece according to one aspect of the present disclosure is a method for manufacturing a workpiece, in which a machining machine having a spindle that holds one of the tool and the workpiece, a holding part that holds the other of the tool and the workpiece, a drive part that moves one of the movable parts, which is the spindle or the holding part, in a predetermined first direction, a position sensor that detects the position of the movable part in the first direction, and a rotation sensor that detects the rotation of the spindle, processes the workpiece with the tool to obtain a workpiece, and the method includes the steps of: moving the movable part in the first direction while the spindle is rotating, bringing the tool into contact with the reference part, detecting deceleration in the rotation of the spindle due to contact between the tool and the reference part based on the detection result by the rotation sensor; and obtaining the position of the movable part in the first direction when the deceleration is detected by the position sensor. [Effects of the Invention]

[0010] According to the above configuration or procedure, it is possible to suitably obtain information on the reference position when the workpiece and the tool are moved relative to each other. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a schematic perspective view showing a main part of a processing machine according to an embodiment of the present disclosure. [Figure 2] FIG. 2 is a schematic perspective view showing an enlarged view of a part of the processing machine of FIG. 1; [Figure 3] FIG. 2 is a cross-sectional view schematically showing a bearing of a main shaft of the processing machine of FIG. 1. [Figure 4] FIG. 2 is a block diagram showing a schematic configuration of a signal processing system of the processing machine shown in FIG. 1; [Figure 5] 5(a) and 5(b) are schematic diagrams for explaining the operation of the processing machine of FIG. 1 for acquiring information on the reference position. [Figure 6] 4 is a flowchart showing an example of a procedure for acquiring information on a reference position in the processing machine of FIG. 1; [Figure 7]7(a), 7(b), and 7(c) are schematic diagrams showing various modified examples relating to detection of deceleration of rotation of a tool. [Figure 8] 8(a), 8(b), and 8(c) are schematic diagrams showing various modified examples relating to the method of rotating the tool. DETAILED DESCRIPTION OF THE INVENTION

[0012] First, an overview of a processing machine according to an embodiment of the present disclosure will be described, and then the details of the processing machine will be described.

[0013] (Overview of the processing machine) Fig. 1 is a schematic perspective view showing a main part of a processing machine 1 according to an embodiment of the present disclosure. Fig. 2 is a schematic perspective view showing an enlarged view of a part of the processing machine 1 of Fig. 1.

[0014] The relationship between the orientations of the various components shown in the drawings and the vertical direction is arbitrary. However, for convenience, the following description may be expressed on the assumption that the relationship between the orientations of the various components and the vertical direction is the relationship illustrated in the drawings. For convenience, the drawings are illustrated with a Cartesian coordinate system XYZ. The Z direction is, for example, a direction parallel to the vertical direction, and the +Z side is, for example, upward.

[0015] The processing machine 1 processes (e.g., cuts) a workpiece 103 using a tool 101. The tool 101 and workpiece 103 are supported and driven by a machine body 3 shown in FIG. 1. The machine body 3 is controlled by a control unit 5 (see FIG. 4). In the illustrated example, the tool 101 is a grinding wheel that performs grinding (which may also be considered as cutting) on ​​the outer periphery for grooving or cutting. The tool 101 is held by a spindle 37 (reference numeral shown in FIG. 2) parallel to the Y direction. The spindle 37 then moves toward the -Z side while rotating around an axis parallel to the Y direction, thereby cutting the workpiece 103. A machining fluid (not shown, e.g., cutting fluid) is supplied from a nozzle 7 to the area where machining is performed.

[0016] The control unit 5 acquires, as a reference position, the Z-direction position of the spindle 37 when the tool 101 is moved to the -Z side and the tool 101 abuts on the workpiece 103 (or another member, as described later). Then, the control unit 5 moves the spindle 37 to a relative position in the Z direction set with respect to the reference position. This allows, for example, the depth of the groove formed on the top surface of the workpiece 103 to be set to a desired size (the relative distance between the reference position and the relative position).

[0017] 5(a) and 5(b) are schematic diagrams for explaining a method for acquiring information on the position that serves as the reference position. FIG. 6 is a flowchart showing an example of the procedure for acquiring information on the position that serves as the reference position. Note that FIG. 6 may be considered as a flowchart showing an example of the procedure for processing executed by the control unit 5.

[0018] In the following description, for convenience, the information on the reference position may be simply referred to as the reference position, and the acquisition of information on the position that serves as the reference position may be simply referred to as the acquisition of the reference position.

[0019] First, as indicated by arrow a1 in Fig. 5(a) and step ST1 in Fig. 6, the tool 101 (or, from another perspective, the spindle 37) is rotated around the rotation axis CL while the tool 101 is away from the workpiece 103 on the +Z side. Furthermore, as indicated by arrow a2 in Fig. 5(a) and step ST2 in Fig. 6, the tool 101 is brought closer to the workpiece 103 while the tool 101 is rotating.

[0020] The rotation speed of the tool 101 at this time is lower than, for example, the rotation speed of the tool 101 when cutting the workpiece 103 with the tool 101. From another perspective, the moment (external moment and / or moment of inertia; the same applies hereinafter) that drives the tool 101 at this time is smaller than the moment that drives the tool 101 during processing.

[0021] Various methods may be used to rotate the tool 101. In the illustrated example, the tool 101 is rotated by supplying fluid from the nozzle 7 toward the outer periphery of the tool 101 in a tangential direction to the outer periphery.

[0022] Thereafter, as shown in Fig. 5(b), when the tool 101 comes into contact with the workpiece 103, the rotation of the tool 101 is decelerated due to frictional force and the like that the tool 101 receives from the workpiece 103. As shown in step ST3 of Fig. 6, the control unit 5 detects this deceleration of the rotation. Furthermore, when the control unit 5 detects the deceleration of the rotation (when a positive determination is made in step ST3), it detects the position of the spindle 37 in the Z direction at this time as shown in step ST4, and sets this detected position in the Z direction as a reference position.

[0023] In the description of this disclosure, deceleration may be used in a broad sense that includes stopping, and in a narrow sense that does not include stopping. Unless otherwise specified, deceleration may include stopping unless a contradiction occurs.

[0024] As described above, in this embodiment, contact of the tool 101 with the workpiece 103 is detected based on the phenomenon in which the rotating tool 101 decelerates upon contact with the workpiece 103. Therefore, the tool 101 or the reference member (here, the workpiece 103) that contacts the tool 101 does not need to be conductive. Also, there is no need to use a dummy blade. Furthermore, if the rotation speed of the tool 101 is reduced (if the moment is reduced), the likelihood of deterioration of the tool 101 and / or the reference member also decreases.

[0025] (Details of the processing machine) As described above, the processing machine 1 has, for example, a machine body 3 including a spindle 37, and a control unit 5 that controls the machine body 3. The processing machine 1 also has a fluid supply unit 9 (see FIG. 4) including a nozzle 7. The control unit 5 may also be used to control the fluid supply unit 9. Furthermore, unlike the above description, the fluid supply unit 9 may be considered as a device separate from the processing machine 1.

[0026] The components of the processing machine 1 will be roughly described below in the listed order. Tool 101 (Figures 1 and 2) Workpiece 103 (Figures 1 and 2) Machine body 3 (Fig. 1, Fig. 2 and Fig. 3) Fluid supply unit 9 (Figures 2 and 4) Control unit 5 (Figure 4) Procedure for obtaining information on the reference position (Fig. 5(a), Fig. 5(b), and Fig. 6) Summary of implementation Modifications (Figs. 7(a) to 8(c))

[0027] (tool) The tool 101 may be any of various tools used for various processes. For example, the tool 101 may be a cutting tool for cutting, a grinding tool for grinding, or a polishing tool for polishing. The cutting tool may be, for example, a milling tool (rotating tool) that rotates itself to cut the workpiece 103 (as shown in the example), or a turning tool that cuts the rotating workpiece 103. Examples of milling tools include milling cutters, drills, and reamers. The grinding tool or polishing tool may use fixed abrasive grains fixed to the tool, or may use free abrasive grains contained in a slurry.

[0028] Unlike the illustrated example, when acquiring the reference position in a mode in which the tool 101 is a turning tool, for example, the turning tool and the workpiece 103 are brought close to each other while the spindle holding the workpiece 103 is rotating. Then, it is detected that the rotation of the workpiece 103 has stopped due to contact between the two, and the position of the tool 101 or the workpiece 103 detected at this time may be acquired as the reference position. Note that in the description of this embodiment, unless otherwise specified, explanations or expressions may be given on the assumption that the tool 101 is a turning tool as in the illustrated example.

[0029] Consider a situation in which the tool 101 or the workpiece 103 (the tool 101 in the illustrated example) is moved in a first direction (the Z direction in the illustrated example) to perform machining, and / or a situation in which a reference position in the first direction is acquired. In this case, the part of the tool 101 that comes into contact with the workpiece 103 in the first direction is arbitrary. In other words, the relationship between the orientation of the tool 101 and the first direction is arbitrary. For example, in a case in which the tool 101 is a milling tool, the contacting part may be the outer periphery (the part on the outside around the rotation axis) (in the illustrated example), or may be the tip.

[0030] As in the illustrated example, in a mode in which the outer periphery of the milling tool contacts the workpiece 103 in a first direction, for example, when acquiring a reference position, the rotation of the tool 101 is likely to be stopped by the contact of the tool 101 with the workpiece 103. This effect becomes stronger, for example, as the diameter becomes larger. From this perspective, the diameter of the tool 101 may be, for example, 1 time or more, 2 times or more, or 5 times or more the maximum length of the tool 101 in the rotation axis direction (or, from another perspective, the maximum thickness).

[0031] 1 and 2, a milling tool is illustrated as the tool 101. More specifically, the tool 101 in the illustrated example is a grinding wheel that performs grinding on the outer periphery, as described above. From another perspective, the tool 101 is a blade having a cutting edge 101a (reference numeral 101a in FIGS. 5(a) and 5(b)) on its outer periphery. The blade is generally plate-shaped (disk-shaped or ring-shaped) with a circular outer edge. The blade is used to form grooves in the workpiece 103 and / or cut (divide) the workpiece 103 by rotating around its axis (around a rotation axis parallel to the Y direction in the illustrated example). The processing machine 1 may be equipped with a single blade (as in the illustrated example), or may be equipped with multiple blades spaced apart from each other in a direction parallel to the rotation axis. Note that the following description may be based on the assumption that a single blade is attached, as in the illustrated example.

[0032] (Work) As can be understood from the above description that the type of machining performed by the tool 101 may be various, the workpiece 103 may also be various. For example, the material of the workpiece 103 may be various, such as metal, ceramic, resin, wood, chemical wood, or a composite material (e.g., carbon fiber reinforced plastic). The shape and dimensions of the workpiece 103 before and / or after machining are arbitrary. The dimensional accuracy required for the workpiece 103 after machining is also arbitrary. For example, in cases where a relatively high accuracy is required, the accuracy (tolerance) may be 10 μm or less, 1 μm or less, or 100 nm or less.

[0033] Consider a situation in which machining is performed by moving the tool 101 or the workpiece 103 (the tool 101 in the illustrated example) in a first direction (the Z direction in the illustrated example) and / or a situation in which a reference position in the first direction is acquired. In this case, the part of the workpiece 103 that comes into contact with the tool 101 in the first direction is arbitrary. From another perspective, the relationship between the orientation of a member that holds the workpiece 103 (a table 25, which will be described later in the illustrated example) and the first direction is arbitrary.

[0034] For example, in an embodiment where the tool 101 is a milling tool (the illustrated example), the contacting portion may be the top surface of the workpiece 103 (the surface opposite to the table 25) (the illustrated example), or, unlike the illustrated example, may be a side surface of the workpiece 103 (the surface facing the side of the table 25). Also, although not particularly illustrated, in an embodiment where the tool 101 is a turning tool, the contacting portion may be the outer peripheral surface of the workpiece 103 (the outer surface around the rotation axis) or the end face (the surface facing in a direction parallel to the rotation axis).

[0035] 1 and 2, a plate-shaped workpiece 103 (substrate) is illustrated as an example. The planar shape of the plate-shaped workpiece 103 before machining is arbitrary, for example, rectangular (as shown in the example) or circular. In the embodiment in which the tool 101 is a disk-shaped blade having a cutting edge 101a on its outer periphery as described above, the blade contributes to, for example, forming a groove extending in a direction (X direction) perpendicular to the rotation axis of the tool 101 on the upper surface (+Z side surface) of the plate-shaped workpiece 103, or dividing the workpiece 103 in the Y direction.

[0036] (machine body) The machine body 3 will be described in the following order. The general machine body 3 that can be used in this embodiment The machine body 3 shown in Figure 1 An example of the bearing configuration of the main shaft 37

[0037] (machine body in general) The machine body 3 supports and drives the tool 101 and the workpiece 103. In other words, the machine body 3 is responsible for the main part of the processing. The machine body 3 may have a variety of configurations, for example, a known configuration.

[0038] For example, machines that perform processing are sometimes distinguished between machine tools and industrial robots (although the boundary between them is not always clear). When such a distinction is made, the machine body 3 (or processing machine 1) may be classified into either category. In the description of this embodiment, an example is taken of a device that is generally classified as a machine tool.

[0039] Furthermore, as can be understood from the above description of the tool 101, the machining that is the subject of the machine body 3 (or the processing machine 1) may be various types of machining, such as cutting, grinding, and / or polishing. Furthermore, the machine body 3 that performs cutting or the like may be one that rotates the tool 101 or one that rotates the workpiece 103.

[0040] The machine body 3 may or may not be a multi-task machine. The machine body 3 may drive one tool 101 (as in the illustrated example), or may be a multi-axis or multi-head machine that simultaneously drives multiple tools 101. The machine body 3 (machining machine 1) that rotates the tool 101 (milling tool) may be, for example, a milling machine, a drill press, a boring machine, or a machining center.

[0041] The machine body 3 moves the tool 101 and the workpiece 103 relatively along, for example, the X-axis, Y-axis, and Z-axis, which are orthogonal to each other. The machine body 3 may be capable of moving the tool 101 and the workpiece 103 relatively along other axes in addition to the above three axes. For example, the machine body 3 (machine 1) may be capable of rotating around at least one axis parallel to any of the above three axes (e.g., a five-axis machining center). The relative movement between the tool 101 and the workpiece 103 along each axis may be achieved by moving the tool 101 or by moving the workpiece 103, as is understood from known machine tools.

[0042] In the description of this embodiment, the orientations of various components, such as the spindle 37 and the table 25, will be described on the assumption that the orientations of these components do not change. For a configuration in which the orientations of components can change, this description may be applied to, for example, the standard orientation of the components, or to a specific orientation different from the standard orientation. The standard orientation may be reasonably determined in light of common technical knowledge.

[0043] In an embodiment in which the tool 101 is a milling tool, the relative relationship between the orientation of the spindle 37, the orientation of the table 25, the vertical direction, and the first direction (Z direction in the illustrated example) for obtaining the reference position is arbitrary. Similarly, in an embodiment in which the tool 101 is a turning tool, the relative relationship between the orientation of the spindle 37, the orientation of the tool post, the vertical direction, and the first direction is arbitrary.

[0044] For example, the main shaft 37 (its rotation axis) may be parallel to (in the illustrated example) or may intersect (for example, perpendicular to) the upper surface of the table 25. Furthermore, the first direction may be parallel to (for example, perpendicular to) the main shaft 37 (in the illustrated example). The first direction may be parallel to (for example, perpendicular to) the upper surface of the table 25 (in the illustrated example).

[0045] (The machine body in the illustrated example) In FIG. 1, the machine body 3 is exemplified by a slicer that can perform cutting by rotating a disk-shaped tool 101 having a cutting edge 101a on the outer periphery.

[0046] 1 has the following components for supporting the workpiece 103: a base 21 installed on the floor of a factory or the like; an X-axis bed 23 fixed on the base 21; a table 25 supported by the X-axis bed 23 and movable in the X direction (horizontal direction); and a chuck 27 fixed on the table 25 and for detachably holding the workpiece 103. Although not particularly shown, the machine body 3 may be configured so that the table 25 can rotate around an axis parallel to the Z axis.

[0047] 1 has the following components as components for supporting and driving the tool 101: the base 21; a Y-axis bed 29 fixed on the base 21; a Y-axis moving section 31 supported by the Y-axis bed 29 and movable in the Y direction (horizontal direction); a Z-axis moving section 33 supported by the Y-axis moving section 31 and movable in the Z direction (vertical direction); a spindle head 35 (not including the spindle 37) fixed to the Z-axis moving section 33; and a spindle 37 (reference numeral shown in FIG. 2) supported by the spindle head 35 to be rotatable about a rotation axis parallel to the Y direction and which detachably holds the tool 101.

[0048] A driving force from a driving source (e.g., an electric motor) not shown is transmitted to table 25, causing table 25 to move in the X direction, thereby moving workpiece 103 supported on table 25 in the X direction relative to tool 101. A driving force from a driving source (e.g., an electric motor) not shown is transmitted to Y-axis moving unit 31, causing Y-axis moving unit 31 to move in the Y direction, thereby moving tool 101 supported on Y-axis moving unit 31 in the Y direction relative to workpiece 103. A driving force from a predetermined driving source (e.g., Z-axis electric motor 39 shown in FIG. 4, which will be described later) is transmitted to Z-axis moving unit 33, causing Z-axis moving unit 33 to move in the Z direction, thereby moving tool 101 supported on Z-axis moving unit 33 in the Z direction relative to workpiece 103. A driving force from a predetermined driving source (e.g., spindle motor 41 shown in FIG. 4) is transmitted to spindle 37, causing spindle 37 to rotate about its axis, thereby rotating tool 101 held by spindle 37 about its axis.

[0049] 1 and 2 are schematic diagrams, and the shapes of the components (21, 23, 25, 27, 29, 31, 33, 35, and 37) shown in the figures are merely schematic. The actual shapes of the components may differ significantly from the shapes shown in the figures. The materials of the components may also be arbitrary. Furthermore, the guides (reference numerals omitted) that guide the moving parts (25, 31, or 33) that move parallel to the support parts (23, 29, or 31) are also shown merely schematic, and may differ from the shapes shown in the figures.

[0050] The guide that guides the moving part (25, 31, or 33) that moves parallel to the support part (23, 29, or 31) may be any appropriate type. For example, the guide may be a sliding guide in which the support part and the moving part slide, a rolling guide in which a rolling element rolls between the support part and the moving part, a hydrostatic guide in which air or oil is interposed between the support part and the moving part, or a combination of two or more of these. Similarly, the bearing of the main shaft 37 may be a sliding bearing, a rolling bearing, a hydrostatic bearing, or a combination of two or more of these.

[0051] The drive source for the parallel movement is, for example, an electric motor. This electric motor may be a rotary motor or a linear motor. The rotational motion of the rotary electric motor may be converted into linear motion by an appropriate mechanism such as a screw mechanism (e.g., a ball screw mechanism). The drive source for the parallel movement may be a hydraulic (hydraulic) or pneumatic type. Similarly, the drive source for the rotation of the main shaft 37 is, for example, a rotary electric motor (main shaft motor 41). However, the drive source for the rotation of the main shaft 37 may be a hydraulic (hydraulic) or pneumatic type. The specific configurations of the various electric motors may be various. The electric motor may be a DC electric motor or an AC electric motor. The AC electric motor may be a synchronous electric motor or an induction electric motor.

[0052] The rotor (not shown) of the main shaft motor 41 and the main shaft 37 are fixed to each other so as to rotate together, for example (including a mode in which parts of them are shared). However, a clutch and / or a transmission may be interposed between the rotor (part or all of it) and the main shaft 37. If a clutch is interposed, the rotor may be disconnected from the main shaft 37 in the operation of acquiring the reference position, thereby reducing the moment of inertia. In the description of this embodiment, unless otherwise specified, the description and expression will be based on the premise that the rotor and the main shaft 37 rotate integrally.

[0053] In a mode in which the spindle motor 41 is a synchronous motor including a permanent magnet, for example, when power is not supplied and the tool 101 is torque-free, an attractive force that stops the rotation of the spindle 37 is generated. Therefore, for example, the possibility of unintended rotation occurring when acquiring a reference position is reduced. From another perspective, rotation by supplying a fluid to the tool 101 is effective. On the other hand, in a mode in which the spindle motor 41 is an induction motor, for example, when power is not supplied and the tool 101 is torque-free, an attractive force that stops the rotation of the spindle 37 is not generated. Therefore, for example, the spindle 37 can be rotated even if the force applied by the fluid to the tool 101 is reduced.

[0054] The chuck 27 is configured as, for example, a vacuum chuck or an electrostatic chuck, and is attached to the table 25 by an appropriate tool such as a machine vise (not shown). Note that, unlike the above description, the chuck 27 may be configured as an inseparable unit with the table 25. Also, the chuck 27 may not be provided, and the workpiece 103 may be fixed to the table 25 by an appropriate jig (for example, a machine vise) separate from the chuck 27.

[0055] Unlike the description of this embodiment, the combination of the table 25 and the chuck 27 may be regarded as the table. When referring to the holding surface of the table that holds the workpiece 103, the holding surface may refer to the holding surface 25a (reference numeral shown in FIG. 2) of the table 25 that indirectly holds the workpiece 103 by holding the chuck 27, or may refer to the holding surface 27a (reference numeral shown in FIG. 2) of the chuck 27 that directly holds the workpiece 103.

[0056] The spindle 37 may hold the tool 101 by its own mechanism (for example, a clamping mechanism), or the tool 101 may be attached by a device including a screw or the like. The blade (tool 101) may be fixed to the spindle 37 by, for example, a member having a shaft that is inserted into a hole formed in the center of the blade, a member that overlaps the blade in the axial direction of the spindle 37, and a screw that is inserted into these members and screwed into the spindle 37, although these are not particularly shown. In such an embodiment, the tool 101 may be the blade itself, or the tool 101 may be the entire combination of the blade and a device for attaching the blade to the spindle 37.

[0057] The spindle 37 is located on the side facing the holding surface 27a of the table 25, and its rotation axis is along (for example, parallel to) the holding surface 27a. When the spindle 37 moves in the Z direction as the first direction, the outer periphery of the blade as the tool 101 comes into contact with the top surface of the workpiece 103, and machining or acquisition of the reference position is performed.

[0058] (An example of the structure of a main shaft bearing) As described above, the bearing of the main shaft 37 may have any configuration. Here, as an example of the bearing of the main shaft 37, the configuration of a hydrostatic bearing will be described.

[0059] FIG. 3 is a schematic cross-sectional view showing an example of the configuration of bearing 43 of main shaft 37, and corresponds to line III-III in FIG.

[0060] A gap is defined between the outer peripheral surface of the spindle 37 and the inner peripheral surface of the spindle head 35. A gas (e.g., air) or a liquid (e.g., oil or water) is supplied to the gap at a predetermined pressure by a pump 45 or the like. In the former embodiment, the bearing 43 is an air bearing. In the case where the fluid is a gas, the compressor is considered to be one embodiment of a pump.

[0061] (Fluid supply section) FIG. 4 is a block diagram showing the configuration of the processing machine 1, focusing on the configuration of the signal processing system.

[0062] The fluid supply unit 9 has a nozzle 7 and a supply unit main body 47 that supplies fluid to the nozzle 7. As described above, the fluid supply unit 9 supplies machining fluid from the nozzle 7 to an area where machining is performed when the workpiece 103 is machined by the tool 101 (hereinafter, sometimes referred to as a "machining area"). In addition, when acquiring a reference position, the fluid supply unit 9 rotates the tool 101 by supplying fluid from the nozzle 7 toward the tool 101.

[0063] The following will provide an outline of the following: ·Processing fluid Fluid supplied when obtaining the reference position The part to which the fluid is applied when obtaining the reference position Nozzle 7 Supply unit body 47

[0064] (processing fluid) As can be understood from the above description of tool 101, the machining fluid (not shown) may be various fluids used for various processes. For example, in a mode in which the process is cutting, the machining fluid may be a cutting fluid (or cutting oil). The main component of the cutting fluid may be oil or water. The machining fluid may also be, for example, a grinding fluid for grinding or a polishing fluid for polishing. The grinding fluid or polishing fluid (slurry) may or may not contain free abrasive grains. In either case of machining, the machining fluid may simply be water. The machining fluid may also be a coolant whose purpose is solely or primarily cooling.

[0065] (Fluid supplied when obtaining the reference position) The type (component) of the fluid supplied to the tool 101 to rotate the tool 101 in the operation of acquiring the reference position is arbitrary. For example, the fluid may be a machining fluid, a liquid other than the machining fluid, or a gas. Examples of gas include air and an inert gas (e.g., nitrogen). In the description of this embodiment, a mode in which a machining fluid is supplied will basically be taken as an example.

[0066] (The part to which the fluid is applied when obtaining the reference position) In the explanation so far, the member to which the fluid is applied to rotate the spindle 37 in the operation of acquiring the reference position is the tool 101. However, in an embodiment in which the workpiece 103 is held by the spindle 37, the member to which the fluid is applied may be the workpiece 103. Note that in either embodiment, the member to which the fluid is applied can be said to be a rotation target held by the spindle 37.

[0067] Furthermore, whether the rotating object is the tool 101 or the workpiece 103, the fluid may be applied to the spindle 37 instead of or in addition to the rotating object. A member (e.g., a blade) for increasing the moment caused by the fluid being applied may be attached to the spindle 37, the rotating object (101 or 103), or a tool for attaching the rotating object. Such a member may be considered as part of the spindle 37 or part of the rotating object. Depending on the shape of the blade, the direction in which the fluid is applied may not include a tangential component, which will be described later, and may be, for example, an axial direction. Note that, for convenience, the description of this embodiment may be based on the assumption that such a member (e.g., a blade) is not provided.

[0068] The fluid is applied to the outer surface of the rotating object (tool 101 or workpiece 103) or the outer surface exposed to the outside of the spindle 37. The outer surface exposed to the outside of the spindle 37 is mentioned to distinguish it from a technology that applies a moment to the spindle 37 by a fluid inside the spindle head 35 for machining (a technology that uses a fluid instead of the spindle motor 41).

[0069] In the description of this embodiment, some expressions are made on the assumption that the member to which the fluid is applied in order to rotate the spindle 37 in the operation of acquiring the reference position is the tool 101. The term tool 101 as the member to which the fluid is applied may be replaced with the term workpiece 103 or the spindle 37 as appropriate, unless a contradiction occurs.

[0070] (nozzle) 2 supplies machining fluid to a machining region when the workpiece 103 is machined by the tool 101. In other words, the machining region is the region of the workpiece 103 that is being machined by the tool 101. For example, in an embodiment in which the tool 101 performs cutting, the machining region is the position where the cutting edge contacts the workpiece 103 and the adjacent region. In an embodiment in which the tool 101 performs grinding or polishing, the machining region is, for example, the contact position between the tool 101 and the workpiece 103 and the adjacent region, or the contact region, and the contact may be indirect via loose abrasive grains.

[0071] The supply of machining fluid to the machining region may be performed in various ways. For example, the nozzle 7 may discharge the machining fluid toward the machining region, or may discharge the machining fluid toward a position on the tool 101 or workpiece 103 away from the machining region so that the machining fluid reaches the machining region by running down the tool 101 or workpiece 103. The nozzle 7 may spray the machining fluid, or may discharge the machining fluid at a flow rate that cannot be considered a spray. The nozzle 7 may discharge (e.g., spray) the machining fluid as a stream having an appropriate cross section, may discharge (e.g., spray) the machining fluid in a shower-like manner, or may spray the machining fluid in a mist-like manner.

[0072] Furthermore, when acquiring the reference position, the nozzle 7 applies the fluid to the outer surface of the tool 101 in a direction that applies a moment around the rotation axis of the spindle 37. When the spindle 37 is rotated in this manner, the position (area) of the tool 101 to which the fluid is applied can be various positions, and the direction in which the fluid applies to the position (from another perspective, the direction in which the fluid is ejected) can also be various directions. Conceptually, for example, the tool 101 can rotate as long as an imaginary line extending from the point of application of the resultant force of the forces exerted by the fluid on the tool 101 in the direction of the resultant force is away from the rotation axis. In other words, if the fluid is applied to the outer surface of the tool 101 in a direction that is biased relative to the rotation axis of the tool 101, the tool 101 will rotate.

[0073] Specifically, for example, when the tool 101 is viewed parallel to its rotation axis, the direction in which the fluid hits may be determined as a direction in which an imaginary line extending from the position where the fluid hits (or the region or the center position of the region) in the direction in which the fluid hits moves away from the rotation axis of the spindle 37. Note that this direction can be considered as a tangent direction to a circle having an arbitrary radius and centered on the rotation axis. Also, for example, when the tool 101 is viewed parallel to its rotation axis, the direction in which the fluid hits may be determined as a tangent direction to a circle passing through the position where the fluid hits. Note that the tangent direction with respect to the direction in which the fluid hits (and / or the direction in which the fluid is ejected) may have a relatively large tolerance, and may be, for example, within a range of 60° or within a range of 30° around the strict tangential direction.

[0074] Also, for example, the direction in which the fluid hits may be orthogonal to the rotation axis of the tool 101 in a torsional positional relationship, or may be inclined in a direction parallel to the rotation axis (Y direction in the illustrated example). Also, for example, the position in which the fluid hits may be the outer periphery of the tool 101 (the outer part around the rotation axis), or may be the surface facing in a direction along the rotation axis of the tool 101 (the surface on the +Y side and / or -Y side in the illustrated example), or may be both the former and the latter.

[0075] When the fluid applied to the tool 101 to rotate the spindle 37 is a liquid, the fluid may be sprayed from the nozzle 7 in various ways. For example, the explanation of the supply manner (such as spraying as a single stream or spraying in a shower) in the explanation of the supply of machining fluid may be used to refer to the supply manner of a fluid for rotation. Furthermore, when the fluid is a liquid, the liquid may be supplied to the tool 101 in a manner that cannot be considered a spray, and the force of the liquid falling may be used to rotate the tool 101.

[0076] The nozzle 7 may have various configurations, for example, it may be similar to a known configuration. Nozzle configurations for realizing the manner in which the liquid is discharged (such as a stream of liquid or a shower of liquid) are known. Furthermore, the nozzle 7 may be capable of switching the manner in which the liquid is discharged, or may not be capable of switching the manner in which the liquid is discharged. In the former case, the switching state of the nozzle 7 may be the same or different when supplying machining fluid and when supplying fluid to rotate the spindle 37.

[0077] Various configurations for attaching and positioning the nozzle 7 may be used, including, for example, known configurations. Specifically, the nozzle 7 may be detachable from the machine body 3. In this case, the nozzle 7 may be considered as a separate element from the processing machine 1, similar to the tool 101 and the workpiece 103. The nozzle 7 may be movable during processing or may be located at a fixed position. The nozzle 7 may be positioned relative to a predetermined element (e.g., the spindle 37) manually or by a robot. In the latter case, the positioning may be performed automatically by the control unit 5 or by operating an operating unit (not shown) of the processing machine 1. In a configuration in which the position of the nozzle 7 is changeable, the position of the nozzle 7 may be the same or different between when supplying machining fluid and when supplying fluid to rotate the spindle 37 in the reference position acquisition operation.

[0078] In the example shown in FIG. 2, the nozzle 7 is located at the tip of a shape-stable bellows (reference numeral omitted). The end of the bellows opposite the nozzle 7 is connected to a block (reference numeral omitted) having a flow path. The block is fixed to the spindle head 35 by an appropriate device. Therefore, the nozzle 7 is movable together with the tool 101 relative to the workpiece 103 (except for rotation around the axis of the tool 101), and its specific position and orientation are determined by manually deforming the bellows. In FIG. 2, the nozzle 7 is positioned so that the machining fluid and the fluid for rotating the spindle 37 hit the cutting edge 101a of the blade serving as the tool 101 in a direction tangential to the cutting edge 101a.

[0079] (Supply unit body) The configuration of supply unit main body 47 may be appropriately configured depending on the type of machining fluid, etc. For example, in an embodiment in which the machining fluid is a cutting fluid, grinding fluid, or polishing fluid, supply unit main body 47 may have a configuration similar to or adapted from the configuration of a device that supplies these machining fluids in a typical machine tool. Also, in an embodiment in which the machining fluid is water, supply unit main body 47 may be configured to receive water from factory equipment and have a valve that allows or prohibits the supply of the water to nozzle 7.

[0080] In the illustrated example, the supply unit main body 47 includes, for example, a machining fluid supply source 49 that supplies the machining fluid, and a control valve 53 that controls the flow of the machining fluid.

[0081] In an embodiment in which the machining fluid is a cutting fluid, grinding fluid, polishing fluid, or the like, machining fluid supply source 49 may include, for example, a tank for storing the machining fluid and a pump for discharging the machining fluid from the tank, both of which are not shown. Control valve 53 may simply allow or prohibit the flow of the machining fluid, or may be capable of controlling the flow rate and / or pressure. Control valve 53 may also be configured by combining multiple valves. Based on commands from control unit 5, the pump (machining fluid supply source 49) and / or control valve 53 may operate to control whether or not the machining fluid is supplied, the flow rate of the machining fluid, and / or the pressure of the machining fluid.

[0082] Although not shown, the supply unit main body 47 may have a compressed air supply source so that the machining fluid can be mixed with compressed air and sprayed as a mist of the machining fluid. The fluid flowing out of the nozzle 7 to acquire the reference position may be compressed air supplied from the above-mentioned supply source.

[0083] In the description of this embodiment, the fluid supply unit 9 is regarded as part of the processing machine 1. In such a case, the fluid supply unit 9 may be provided in a manner that allows it to be perceived as part of the processing machine 1 from the outside, or may be provided in a manner that does not allow it to be perceived as such. For example, part or all of the fluid supply unit 9 may be housed in a housing (not shown) together with the machine main body 3 shown in FIG. 1 , or may be housed in a housing separate from the machine main body 3. Part or all of the fluid supply unit 9 may be disposed in or on the base 21 of the machine main body 3.

[0084] (Control unit) The control unit 5 shown in Fig. 4 may be configured to include, for example, a computer. The computer may be configured to include, for example, a central processing unit (CPU), read only memory (ROM), random access memory (RAM), and an external storage device, although not specifically shown. In Fig. 4, the RAM and / or external storage device are shown as storage unit 67. The CPU executes programs stored in the ROM and / or external storage device to configure various functional units (59, 61, 63, and 65) that perform control, etc. Note that the control unit 5 may include a logic circuit that performs only certain processes.

[0085] The control unit 5 is a conceptualized control unit for the entire processing machine 1. The control unit 5 may be integrated in one location in terms of hardware, or may be distributed across multiple locations. In the latter example, a control unit that controls the machine body 3 and a control unit that controls the fluid supply unit 9 may be provided separately in terms of hardware. The two may or may not perform control in synchronization. Synchronization may be achieved by one operating based on a signal from the other, or by providing a higher-level control unit for both.

[0086] The control unit 5 has, as functional units for performing control etc., functional units (59, 61, and 63) that control the machine body 3, and a fluid control unit 65 that controls the fluid supply unit 9. More specifically, the former are a movement control unit 59 that controls the relative movement between the spindle 37 and the table 25 during machining, a rotation control unit 61 that controls the rotation of the spindle 37 during machining, and a reference position acquisition unit 63 that controls the operation when acquiring a reference position. Note that some of these various functional units may be shared.

[0087] The movement control unit 59 controls the drive source that drives the moving unit based on, for example, the detection value of a position sensor that detects the position of the moving unit (25, 31, or 33) on each axis (e.g., X-axis, Y-axis, or Z-axis). Note that position sensors may not be provided for axes other than the axis related to the first direction for which the reference position is acquired (Z-axis in the illustrated example). From another perspective, open-loop control may be performed on the other axes without feedback control based on position sensors.

[0088] 4 illustrates, among the three-axis configuration, a configuration for controlling Z-axis motor 39 based on Z-axis position sensor 69 that detects the position in the Z direction of Z-axis moving section 33. The Z-direction position of Z-axis moving section 33 here refers to, for example, the position in the Z direction in an absolute coordinate system (or, from another perspective, a machine coordinate system), and strictly speaking, refers to, for example, the position in the Z direction relative to a member (such as Y-axis moving section 31) that is intended to be immobile in the Z direction.

[0089] The position sensor may directly detect the position of the moving part (as in the illustrated example), or may detect the operating amount of the drive source that drives the moving part (for example, the amount of rotation of a rotary electric motor). From another perspective, the feedback control based on the detection value of the position sensor may be a full-closed loop (as in the illustrated example) or a semi-closed loop. The position sensor may have various specific configurations, such as a linear encoder (as in the illustrated example) or a laser length measuring device. The linear encoder may be optical or magnetic, and may be absolute or incremental.

[0090] The rotation control unit 61 controls the spindle motor 41 that drives the spindle 37 based on the detection value of a rotation sensor 71 that detects the rotation (more specifically, for example, the rotation speed) of the spindle 37. The rotation sensor 71 may be one that directly detects the rotation of the spindle 37, or one that detects the rotation of the spindle motor 41 (as in the illustrated example). From another perspective, the rotation sensor 71 may be one that is provided in the spindle motor 41 (as in the illustrated example), or may not be one that is not. Also, the spindle 37 and the spindle motor 41 may share a portion of their own, making the above-mentioned distinction impossible. The rotation sensor 71 may have various specific configurations, such as an encoder or a resolver. The encoder may be optical or magnetic, and may be absolute or incremental.

[0091] The control by the movement control unit 59 and the rotation control unit 61 is performed, for example, in accordance with an NC program D1 stored in the storage unit 67 (RAM and / or external storage device). The NC program D1 prescribes one or more values ​​for at least one of the following: absolute coordinates (machine coordinates) of the target position, relative coordinates of the target position, target movement amount, and target rotation speed. The movement control unit 59 and the rotation control unit 61 then control the drive sources (39, 41, etc.) based on the detection values ​​of the position sensor (69, etc.) and the rotation sensor 71 so as to realize the various target values.

[0092] The acquired information D3 of the reference position is stored in the storage unit 67 (RAM and / or external storage device). In the control performed in accordance with the above-mentioned NC program D1, the information D3 is used appropriately. The manner of use of the information D3 may be various.

[0093] For example, the NC program D1 may include a program (one or more blocks) for moving the spindle 37 (tool 101) in the Z-axis direction to a relative position (target position) set with respect to a reference position, thereby allowing the reference position to be used.

[0094] The relative position with respect to the reference position may be defined in one or more blocks by relative coordinates with respect to the reference position or by the amount of movement from the reference position. Furthermore, the movement to the relative position in the Z-axis direction may or may not involve movement in other axes.

[0095] In the above-described usage mode, the relationship between movement based on the reference position and the processing content is also arbitrary. For example, a groove of a predetermined depth may be formed by moving the blade (tool 101) from the reference position or a relative position set on the +Z side of the reference position to a relative position set on the -Z side of the reference position. In other words, the reference position may be used as a position for determining the cutting depth from the top surface of the workpiece 103.

[0096] Unlike the above, the reference position may be used in a manner in which the reference position is not defined in the NC program. For example, the reference position may be used to detect a deviation between the actual position of the tool 101 and / or workpiece 103 and the position of the tool 101 and / or workpiece 103 assumed in machine coordinates, and to correct the overall machine coordinates defined in the NC program or the overall position detected by the position sensor. Note that such a usage manner can also be considered as ultimately moving the spindle 37 to a relative position set with respect to the reference position.

[0097] The reference position acquisition unit 63 controls the machine body 3 (more specifically, the Z-axis motor 39) and the fluid supply unit 9 so as to perform operations for acquiring the reference position. In FIG. 4, the arrows representing this control are omitted. The reference position acquisition unit 63 may use the movement control unit 59 in controlling the Z-axis motor 39, and may control the fluid control unit 65 in controlling the fluid supply unit 9. From another perspective, the reference position acquisition unit 63 may share a portion with the movement control unit 59 and the fluid control unit 65.

[0098] The reference position acquisition unit 63 acquires, as the reference position, the position of the spindle 37 in the Z-axis direction when deceleration of the rotation of the spindle 37 is detected. The sensor that detects the position of the spindle 37 at this time is, for example, the Z-axis position sensor 69 that the movement control unit 59 uses for feedback control. This allows the reference position and the relative position set with respect to the reference position to be identified based on the detection value from the same sensor, thereby improving the machining accuracy.

[0099] Although not specifically shown, the operating procedure for acquiring the reference position is, for example, different from the operating procedure during machining and is defined by a program separate from the NC program. This separate program is, for example, included in a program executed by the CPU to configure the reference position acquisition unit 63. The program for configuring the reference position acquisition unit 63 may be stored in advance in the storage unit 67 by the manufacturer of the processing machine 1, or may be installed in an existing processing machine 1 by an operator. Unlike the above description, part of the operating procedure for acquiring the reference position may be defined by a program created in the same way as the NC program.

[0100] The sensor that detects the deceleration of rotation to acquire the reference position may be the rotation sensor 71 that the rotation control unit 61 uses for feedback control during machining (as in the illustrated example), or may be another sensor. In the former mode, for example, the configuration is simplified. In the latter mode, for example, a sensor that can detect smaller changes in the rotation angle than the rotation sensor 71 is provided, making it possible to detect the deceleration of rotation with high accuracy. Note that, for convenience, the description of this embodiment may be expressed assuming the former mode.

[0101] The fluid control unit 65 controls the fluid supply unit 9 so that machining fluid is supplied, for example, during machining and when the reference position is acquired. Specific controlled objects are, for example, the control valve 53 and the machining fluid supply source 49 (for example, a pump not shown).

[0102] (Procedure for obtaining reference position) The outline of Figures 5(a), 5(b) and 6 has already been described.

[0103] The operation for acquiring the reference position shown in these figures may be started when an operator performs a predetermined operation on an operation unit (not shown) of the processing machine 1, or may be started automatically by the control unit 5 without an operation by the operator. In the latter embodiment, examples of the timing at which the control unit 5 automatically acquires the reference position include when a series of machining operations defined by an NC program is started, when a specific machining operation among the series of machining operations is started, and when the amount of wear detected by a sensor (not shown) that detects wear on the tool 101 exceeds a predetermined threshold.

[0104] When acquiring the reference position, the control unit 5 controls the fluid supply unit 9 to supply machining fluid from the nozzle 7 to the tool 101. At this time, the control unit 5 also places the spindle motor 41 in a torque-free state, for example. That is, no power is supplied to the spindle motor 41. This causes the spindle 37 to rotate as indicated by arrow a1. The control unit 5 also controls the Z-axis motor 39 to move the spindle 37 toward the table 25 as indicated by arrow a2.

[0105] In the operation of acquiring the reference position, the rotation and movement of the spindle 37 may be started simultaneously, or one may be started before the other. Furthermore, the outflow of machining fluid from the nozzle 7 may be continued until the stop of the rotation of the spindle 37 is detected, or may be stopped before a deceleration of the rotation of the spindle 37 (due to contact) is detected. In the former mode, for example, the spindle 37 can be reliably rotated until the rotation of the spindle 37 is decelerated due to contact with the workpiece 103. In the latter mode, for example, by lowering the rotation speed of the spindle 37 when the spindle 37 contacts the workpiece 103, the likelihood of deterioration of the tool 101 and / or the workpiece 103 can be reduced.

[0106] The rotation speed of the spindle 37 (or, from another perspective, the pressure of the fluid, etc.) when acquiring the reference position may be set as appropriate. For example, the rotation speed at this time may be set sufficiently lower than the rotation speed when machining is performed by the tool 101. From another perspective, the inertia moments of the spindle 37 and the tool 101, and / or the moment externally applied to the tool 101 may be set smaller than those when machining is performed.

[0107] The specific rotational speed or moment during machining or reference position acquisition may be set appropriately depending on the specific configuration of the machine body 3 to which the present embodiment is applied, the type of tool 101, the type of workpiece 103, etc. As an example, the rotational speed during machining (more specifically, for example, immediately before or when the tool 101 is in contact with the workpiece 103) may be 2000 rpm (rotations per minute) or more, while the rotational speed during the operation to acquire the reference position (more specifically, for example, immediately before the tool 101 contacts the workpiece 103) may be 200 rpm or less, 100 rpm or less, 50 rpm or less, or 10 rpm or less. From another perspective, the rotational speed during the operation to acquire the reference position may be 1 / 10 or 1 / 100 of the rotational speed during machining or less.

[0108] The rotation speed for machining is set, for example, by an operator of the processing machine 1. From another perspective, the rotation speed for machining is specified by an NC program. Therefore, when focusing on the processing machine 1 in the distribution stage, the relative relationship between the rotation speed for machining and the rotation speed for acquiring the reference position does not need to be considered a configuration requirement of the processing machine 1. However, if the processing machine 1 has a lower limit value that can be set by the operator or if the manufacturer has a recommended lower limit value in its specifications, the rotation speed for acquiring the reference position may be compared to the lower limit value to determine whether the above-mentioned relationship holds. When referring to the rotation speed for machining specified by the NC program, if the rotation speed specified in the NC program is not constant, the lowest rotation speed may be compared with the rotation speed for acquiring the reference position.

[0109] The number of rotations for acquiring the reference position may be set, for example, by the manufacturer of the processing machine 1, or may be set by the operator of the processing machine 1. From another perspective, information on the number of rotations for acquiring the reference position may be stored in advance in the storage unit 67, or may be input to the control unit 5 by operating an operation unit (not shown) of the processing machine 1. Note that when the number of rotations for acquiring the reference position is set by the operator, when focusing on the processing machine 1 in the distribution stage, the number of rotations for acquiring the reference position does not necessarily have to be considered a constituent element of the processing machine 1, just like the number of rotations for processing.

[0110] The moving speed of the spindle 37 during the operation to acquire the reference position may be set appropriately. This moving speed may be constant or variable (the speed may be variable). An example of the latter is a mode in which the spindle 37 decelerates when approaching a predicted position of the reference position. The predicted position may be input to the control unit 5 by an NC program or by an operator operating an operation unit (not shown). The moving speed when the tool 101 contacts the workpiece 103 to acquire the reference position may be slower, equal to, or faster than the moving speed when the tool 101 contacts the workpiece 103 for machining. The moving speed may be set by the manufacturer of the processing machine 1 or by an operator of the processing machine 1. From another perspective, information about the moving speed may be stored in advance in the memory unit 67 or may be input to the control unit 5 by operating an operation unit (not shown) of the processing machine 1. For example, the moving speed when the tool 101 contacts the workpiece 103 to acquire the reference position is 10 mm / min or less. Of course, the movement speed can be faster than this.

[0111] The control unit 5 may control the Z-axis motor 39 to move the spindle 37 to a target position on the -Z side of the predicted position of the reference position. The spindle 37 may then be decelerated (and even stopped) in the Z direction due to the force received from the workpiece 103. The control unit 5 may control the Z-axis motor 39 to generate an appropriate torque so that the force with which the tool 101 pushes the workpiece 103 toward the -Z side does not become excessively large. The control unit 5 may also detect the deceleration or stop of the spindle 37 in the Z direction based on the detection value of an appropriate sensor, and stop driving the Z-axis motor 39 in response to the detection. Examples of the sensor include a Z-axis position sensor 69 and a sensor that detects the power supplied to the Z-axis motor 39.

[0112] Furthermore, the control unit 5 may stop the movement of the spindle 37 toward the -Z side when deceleration of the rotation of the spindle 37 due to contact between the tool 101 and the workpiece 103 is detected. The detection of deceleration at this time may be common to the detection of deceleration of rotation when acquiring the position of the spindle 37 in the Z direction as the reference position. In this case, the control unit 5 may acquire the position of the spindle 37 at the time of detection of deceleration of rotation as the reference position, or may acquire the position of the spindle 37 from after detection of rotation to before stop of movement toward the -Z side as the reference position, or may acquire the position of the spindle 37 after movement toward the -Z side is stopped as the reference position. However, in this disclosure, unless otherwise specified, the strictness as described above is not an issue, and in all of the above aspects, the position of the spindle 37 when deceleration of rotation is detected is considered to be the position of the spindle 37. Unlike the above, the detection of deceleration of rotation for stopping movement toward the -Z side and the detection of deceleration of rotation for acquiring the reference position may be detected (determined) separately.

[0113] As described above, when the control unit 5 is rotating the tool 101 using fluid from the nozzle 7 and bringing the tool 101 closer to the workpiece 103, and the rotation sensor 71 (or another sensor) detects a deceleration in rotation, the control unit 5 stores the detection value of the Z-axis position sensor 69 at that time in the memory unit 67 as a reference position.

[0114] The detection of deceleration caused by contact between the tool 101 and the workpiece 103 may be performed as appropriate. For example, the control unit 5 receives a signal in real time corresponding to the number of rotations (or, from another perspective, the rotational speed) detected by the rotation sensor 71. The control unit 5 may then determine that deceleration has occurred when the number of rotations identified from the received signal becomes equal to or less than a predetermined threshold. Also, for example, in a mode in which a moment is applied to the tool 101 only at the beginning of the movement of the tool 101 toward the -Z side and the rotation decelerates from the beginning of the movement, it may be determined that the rotation has stopped when the absolute value of the rate of change of the number of rotations exceeds a predetermined threshold (when deceleration occurs suddenly). The determination may be made by the rotation sensor 71 rather than by the control unit 5. In other words, the control unit 5 may receive a signal of the determination result regarding deceleration from the rotation sensor 71.

[0115] The threshold value may be set by the manufacturer of the processing machine 1 or by the operator of the processing machine 1. From another perspective, information about the threshold value may be stored in advance in the storage unit 67, or may be input to the control unit 5 by operating an operation unit (not shown) of the processing machine 1. The specific value of the threshold value may be set as appropriate. In an embodiment in which deceleration is detected when the rotation speed falls below a predetermined threshold value, the threshold value may be a value (0 rpm) that essentially corresponds to detection of a stop of rotation. Examples of the threshold value for the rotation speed include any value equal to or less than 20 rpm, any value equal to or less than 10 rpm, any value equal to or less than 5 rpm, or any value equal to or less than 1 rpm. This threshold value may be appropriately combined with the previously described example of the rotation speed before contact so as not to contradict.

[0116] 5(a) and 5(b) may be performed manually or by an operator operating an operation unit (not shown) of the processing machine 1. Examples of such operations include rotation of the spindle 37 and / or movement of the spindle 37 in the -Z direction. When the operator operates to move the spindle 37 in the -Z direction, a manual pulse generator (not shown) may be used.

[0117] In the explanations so far, the workpiece 103 has been given as an example of the reference member against which the tool 101 abuts when acquiring the reference position. However, the reference member may be another member that is immovable relative to the workpiece 103. For example, the reference member may be the table 25 or the chuck 27, or a dedicated member for acquiring the reference position that is detachably fixed to the table 25 or the chuck 27. However, the dedicated member may be considered as part of the table 25 or the chuck 27. In the explanations of acquiring the reference position in this disclosure, the term workpiece 103 may be replaced with the term other reference member as described above, unless a contradiction occurs.

[0118] (Summary of the embodiment) As described above, the processing machine 1 has the spindle 37, the holder (table 25), the drive unit (Z-axis motor 39), the position sensor (Z-axis position sensor 69), the rotation sensor 71, and the control unit 5. The spindle 37 holds one of the tool 101 and the workpiece 103 (the tool 101 in the illustrated example). The holder (table 25) holds the other of the tool 101 and the workpiece 103 (the workpiece 103 in the illustrated example). The Z-axis motor 39 moves the movable unit (spindle 37), which is one of the spindle 37 and the table 25, in a predetermined first direction (Z direction). The Z-axis position sensor 69 detects the position of the spindle 37 in the Z direction. The rotation sensor 71 detects the rotation of the spindle 37. When the workpiece 103 is machined by the tool 101 while the spindle 37 is rotating, the control unit 5 controls the Z-axis motor 39 based on the detection value of the Z-axis position sensor 69 to move the spindle 37 in the Z direction to a relative position set with respect to a predetermined reference position. Furthermore, when the workpiece 103 or a member that is immovable with respect to the workpiece 103 (for example, the table 25) is referred to as the reference member, the control unit 5 acquires, as the reference position, the position detected by the Z-axis position sensor 69 when a predetermined signal is input in a state where the rotation of the spindle 37 is detected by the rotation sensor 71 and the spindle 37 moves in the Z direction so that the tool 101 and the reference member are in contact in the Z direction.

[0119] From another perspective, the method for manufacturing a workpiece according to this embodiment uses a processing machine 1 to machine a workpiece 103 with a tool 101 to obtain a workpiece. The processing machine 1 has a spindle 37, a holder (table 25), a drive unit (Z-axis motor 39), a position sensor (Z-axis position sensor 69), and a rotation sensor 71. The spindle 37 holds one of the tool 101 and the workpiece 103 (the tool 101 in the illustrated example). The holder (table 25) holds the other of the tool 101 and the workpiece 103 (the workpiece 103 in the illustrated example). The Z-axis motor 39 moves the movable unit (spindle 37), which is one of the spindle 37 and the table 25, in a predetermined first direction (Z direction). The Z-axis position sensor 69 detects the position of the spindle 37 in the Z direction. The rotation sensor 71 detects the rotation of the spindle 37. The manufacturing method has the following steps. When the workpiece 103 or a member (e.g., table 25) that is immovable relative to the workpiece 103 is referred to as a reference member, steps ST1 and ST2 are performed in which the spindle 37 is moved in the Z direction while the spindle 37 is rotating to bring the tool 101 into contact with the reference member. Step ST3 is performed in which a deceleration of the rotation of the spindle 37 caused by the contact between the tool 101 and the reference member is detected based on the detection result by the rotation sensor 71. Step ST4 is performed in which the position of the spindle 37 in the Z direction when the deceleration is detected is obtained by the Z-axis position sensor 69.

[0120] Therefore, for example, as described above, the tool 101 and the reference member (here, the workpiece 103) that comes into contact with the tool 101 do not need to be conductive. Also, there is no need to use a conductive dummy tool instead of the tool 101.

[0121] The predetermined signal that triggers acquisition of the reference position is a signal from the rotation sensor 71 that corresponds to deceleration (which may include stopping) of the rotation of the main shaft 37. As described above, the signal here may be, for example, a signal indicating the number of rotations, or a signal indicating the result of determination as to whether deceleration has occurred.

[0122] In this case, for example, the operations from detecting deceleration to acquiring the reference position are performed automatically, so the variation in the relative relationship between deceleration and the reference position is reduced compared to a mode in which an operator is involved (this mode is also included in the technology related to the present disclosure, and will be described later with reference to Figures 7(b) and 7(c)). As a result, the accuracy of the reference position is improved. In addition, the burden on the operator is reduced.

[0123] The first direction (Z direction) for acquiring the reference position may be a direction intersecting (e.g., perpendicular to) the rotation axis of the spindle 37. From another perspective, in an embodiment in which the tool 101 is a milling tool, as in the illustrated example, the outer periphery of the milling tool may come into contact with a reference member (e.g., workpiece 103) when acquiring the reference position. Alternatively, unlike the illustrated example, in an embodiment in which the tool 101 is a turning tool, the outer periphery of the reference member (e.g., workpiece 103) may come into contact with the tool 101 when acquiring the reference position.

[0124] In this case, although it depends on the configuration of the milling tool (tool 101), for example, it is easier to decelerate the rotation of the milling tool by contacting the workpiece 103 compared to a mode in which the tip of the milling tool contacts the workpiece 103 (this mode is also included in the technology related to the present disclosure). The reason for this is that the distance from the rotation axis of the milling tool to the contact position between the milling tool and the workpiece 103 is likely to be longer, and / or the contact area between the outer periphery of the milling tool and the workpiece 103 is likely to be larger.

[0125] The spindle 37, which holds one of the tool 101 and the workpiece 103, may hold the tool 101. A holder which holds the other of the tool 101 and the workpiece 103 may be a table (table 25 and / or chuck 27) which is located on one side (-Z side) in the first direction (Z direction) of the spindle 37 and holds the workpiece 103. The tool 101 may be a grinding wheel which performs grinding with its outer periphery (the outer portion around the rotation axis; cutting edge 101a). The reference position may be a position where the outer periphery of the tool 101 abuts against the workpiece 103 or the table (more specifically, the surface on the other side (+Z side) in the Z direction).

[0126] In this case, for example, a relatively large distance (blade radius) is ensured from the rotation axis CL of the tool 101 to the point where the tool 101 contacts the workpiece 103, so the rotation of the tool 101 is likely to be decelerated. As a result, it is easy to apply the method of acquiring the reference position in this embodiment. Also, since the position where the cutting edge 101a contacts is set as the reference position, the amount of cutting (groove depth) from the workpiece 103 can be controlled with high precision. When the cutting edge 101a becomes worn, the reference position can be acquired again, so the precision of the amount of cutting can be maintained.

[0127] The processing machine 1 may further include a fluid supply unit 9. Here, the tool 101 or workpiece 103 (the tool 101 in the illustrated example) held by the spindle 37 is referred to as a rotation target. In this case, the fluid supply unit 9 may realize the rotation of the spindle 37 in the operation of acquiring the reference position by applying a fluid to the outer surface of the rotation target.

[0128] In this case, for example, the reference position can be acquired by rotating the spindle 37 using a drive source other than the drive source (spindle motor 41) that drives the spindle 37 for machining. Therefore, for example, compared to an embodiment in which the spindle 37 is rotated by the spindle motor 41 to acquire the reference position (this embodiment may also be included in the technology according to the present disclosure), the rotation speed when acquiring the reference position can be set without depending on the performance of the spindle motor 41. Consequently, for example, it is easier to lower the rotation speed when acquiring the reference position. Furthermore, for example, compared to an embodiment in which a fluid is applied only to the outer surface of the spindle 37 (this embodiment may also be included in the technology according to the present disclosure; this will be described later with reference to FIG. 8(b)), it is easier to use a device that supplies machining fluid to the tool 101 or workpiece 103 during machining as a device for acquiring the reference position. From another perspective, in an embodiment in which a device that supplies machining fluid during machining is also used to acquire the reference position, the configuration of the device can be simplified. Although a device for supplying machining fluid has been taken as an example of a device used to acquire the reference position, other devices such as a device for supplying cleaning air may also be used.

[0129] The tool 101 may be a grinding wheel (e.g., a blade) that performs grinding on its outer periphery. The fluid supply unit 9 may apply fluid to the outer periphery of the tool 101 in a tangential direction to the outer periphery, thereby realizing rotation of the spindle 37 in the operation of acquiring the reference position.

[0130] In this case, for example, the above-mentioned effect that a device for supplying machining fluid can be easily used to acquire the reference position can be achieved. Also, since the fluid is applied to a position that is a relatively long distance from the rotation axis of the tool 101, it is easy to rotate the tool 101. As a result, for example, it is easy to reduce the load on the fluid supply unit 9 when acquiring the reference position.

[0131] The fluid supply unit 9 may have a nozzle 7 that supplies a machining fluid as a fluid to be supplied to realize the rotation of the spindle 37 when the reference position is acquired.

[0132] In this case, the configuration is simplified compared to, for example, an embodiment in which fluid is supplied from a nozzle separate from the nozzle 7 when acquiring the reference position (this embodiment may also be included in the technology according to the present disclosure, and will be described later with reference to FIG. 8(a)). Furthermore, for example, when the tool 101 is replaced with a different type of tool, adjusting the position of the nozzle 7 for machining also adjusts the position of the nozzle for acquiring the reference position, thereby reducing the workload on the operator.

[0133] The rotation speed of the spindle 37 immediately before the tool 101 contacts the reference member (for example, the workpiece 103) in the operation of acquiring the reference position may be lower than the rotation speed of the spindle 37 when the tool 101 processes the workpiece 103.

[0134] In this case, for example, the possibility that the tool 101 and / or the reference member will be deteriorated when the reference position is acquired is reduced. As described above, since the rotation speed for processing is set by the operator, the above-mentioned characteristics do not need to be specified for the processing machine 1 at the distribution stage.

[0135] The rotation speed of the spindle 37 when machining the workpiece 103 may be 2000 rpm or more. The rotation speed of the spindle 37 immediately before the tool 101 comes into contact with a reference member (e.g., the workpiece 103) in the operation of acquiring the reference position may be 200 rpm or less. From another perspective, the rotation speed of the spindle 37 immediately before the tool 101 comes into contact with a reference member in the operation of acquiring the reference position may be 1 / 10 or less of the rotation speed of the spindle 37 when machining the workpiece 103.

[0136] In these cases, for example, the rotation speed in the operation for acquiring the reference position is sufficiently lower than the rotation speed for machining, thereby reducing the possibility that at least one of the tool 101 and the reference member will be deteriorated due to contact between them during the operation for acquiring the reference position.

[0137] The main shaft 37 may be supported by an air bearing (bearing 43 shown in FIG. 3).

[0138] In this case, for example, compared to other types of bearings, the frictional force that tries to stop the spindle 37 is small, and the spindle 37 can be rotated with a relatively small moment. As a result, for example, in the operation of acquiring the reference position, the moment applied to the spindle 37 from the outside and / or the moment of inertia of the spindle 37 can be reduced. Furthermore, the moment that the tool 101 applies to the workpiece 103 when the tool 101 comes into contact with the workpiece 103 can be reduced. As a result, the likelihood of deterioration of the tool 101 and / or the reference member due to acquisition of the reference position is reduced.

[0139] In the above embodiment, the table 25 is an example of a holding part that holds the other of the tool and the workpiece. The Z direction is an example of a first direction. The spindle 37 is an example of a movable part. The Z-axis motor 39 is an example of a drive part. The Z-axis position sensor 69 is an example of a position sensor. The workpiece 103, the chuck 27, and the table 25 are each an example of a reference member. The machining fluid is an example of a fluid.

[0140] (Variation) Various modified examples will be described below. The modified examples will be roughly described in the following order. Three modified examples relating to detection of deceleration of rotation of the main shaft 37 (FIGS. 7(a) to 7(c)) Three variations of the method of rotating the main shaft 37 (FIGS. 8(a) to 8(c))

[0141] (Modification relating to deceleration detection) 7(a) to 7(c) are diagrams showing modified examples relating to detection of deceleration of rotation of the spindle 37 during an operation for acquiring a reference position. In these figures, the tool 101 and the spindle 37 are shown schematically as viewed from the side.

[0142] In the modification of Fig. 7(a), the deceleration of the spindle 37 (the rotation of the spindle 37) during the operation to acquire the reference position is detected by a rotation sensor 71A different from the rotation sensor 71 provided on the spindle motor 41. The rotation sensor 71A detects the rotation of the tool 101 (or the spindle 37; the same applies hereinafter) in a non-contact manner, for example. Such a rotation sensor 71A may be, for example, an optical or magnetic sensor.

[0143] Specifically, for example, the tool 101 (which may include a device for attaching the tool body to the spindle 37 as described above) has a detectable portion 72 that moves in the circumferential direction as the spindle 37 rotates. The detectable portion 72 may be located partially around the rotation axis of the spindle 37, or may form a repeating pattern and extend over substantially the entire circumference around the rotation axis of the spindle 37. In an optical type, the detectable portion 72 may be, for example, a portion that reflects or transmits light. In a magnetic type, the detectable portion 72 may be, for example, a magnet. Then, the rotation sensor 71A detects the passage of the detectable portion 72 in the circumferential direction relative to the rotation sensor 71A based on changes in the detected light or magnetism, thereby detecting the rotation of the tool 101.

[0144] The rotation sensor 71A may be used for feedback during machining instead of the rotation sensor 71, or may be dedicated to obtaining a reference position. As mentioned in the description of the embodiment, in the former case, the configuration is simplified. Furthermore, full-closed loop feedback control is expected to improve machining accuracy. In the latter case, the rotation sensor 71A is a sensor that can detect smaller changes in the rotation angle than the rotation sensor 71, and rotation deceleration can be detected with high accuracy. Note that, as in the embodiment, detection of deceleration based on the detected value of the rotation speed may be performed by either the control unit 5 or the rotation sensor 71A.

[0145] As described above, the detectable portion 72 may be located on the spindle 37, or on the tool 101 or workpiece 103 held by the spindle 37. The rotation sensor 71A may be a non-contact type that detects the rotation of the spindle 37 based on the detection of the passage of the detectable portion 72 in the circumferential direction of the spindle 37.

[0146] In this case, for example, since the rotation of the tool 101, which is directly affected by contact, is detected, the detection accuracy of the reference position is improved. Also, for example, it is easy to retrofit a rotation sensor 71A with detection accuracy suitable for detecting low-speed rotation of the tool 101. As a result, for example, it is easy to apply the technology according to the present disclosure to an existing processing machine 1.

[0147] In the modified example of FIG. 7(b), the control unit 5 acquires the reference position not when a predetermined signal (a signal corresponding to deceleration) is input from the rotation sensor 71, but when a predetermined signal is input from the input unit 75 operated by the operator. More specifically, for example, the number of rotations detected by the rotation sensor 71 is displayed in real time on the display 73. While the tool 101 is rotating and moving in the −Z direction, the operator determines, based on the number of rotations displayed on the display 73, whether the rotation of the spindle 37 has decelerated due to contact between the tool 101 and the workpiece 103. Then, when the operator determines that the rotation has decelerated, the operator performs a predetermined operation on the input unit 75 to input a signal from the input unit 75 to the control unit 5 to instruct acquisition of the reference position.

[0148] In this embodiment, the movement of the tool 101 to the -Z side may be performed, for example, by the operator performing a predetermined operation on the input unit 75 (more specifically, for example, a manual pulse generator (not shown) included in the input unit 75). Then, when the operator determines that the spindle 37 has decelerated based on the number of rotations displayed on the display 73, the operator stops the operation of moving the tool 101 to the -Z side or does not resume the operation of moving the tool 101. Thereafter, an operation is performed to instruct acquisition of the reference position as described above. When the operation to instruct acquisition of the reference position is performed, the control unit 5 acquires the position detected by the Z-axis position sensor 69 at that time as the reference position.

[0149] As can be understood from the above description, the signal instructing acquisition of the reference position may be input after the movement of the tool 101 toward the -Z side has stopped, rather than while the tool 101 is moving toward the -Z side. From another perspective, for example, when the position of the spindle 37 in the Z direction when deceleration of the rotation of the spindle 37 is detected is acquired as the reference position by the Z-axis position sensor 69, the time when the deceleration of the rotation is detected and the time when the position that becomes the reference position is detected by the Z-axis position sensor 69 may be different.

[0150] The display 73 may have any configuration. For example, the display 73 may also display other information, or may only display the rotation speed. Examples of the former include a liquid crystal display or an organic electroluminescence (EL) display that can display any image. Such a display may constitute a touch panel included in the input unit 75. Examples of the latter include an LED (light emitting diode) or liquid crystal display that displays numbers using multiple segments, a display that rotates a member with letters drawn on it, or a display that points to a number on a scale using a rotating needle.

[0151] The input unit 75 may have any configuration. The illustrated input unit 75 may be considered as a conceptual representation of one or more input devices included in the processing machine 1. The input unit 75 may include, for example, a touch panel, a mechanical switch, and a manual pulse generator, although these are not particularly illustrated. The operation to instruct acquisition of the reference position described above may be performed on, for example, the touch panel or the mechanical switch.

[0152] As described above, the processing machine 1 may have the display 73 that displays the rotation speed of the spindle 37 detected by the rotation sensor 71, and the input unit 75 that accepts operations by the operator. The predetermined signal that triggers acquisition of the reference position may be a signal from the input unit 75.

[0153] In this case, for example, when applying the technology according to the present disclosure to an existing processing machine 1, it is not necessary to change or only a small amount of the program of the control unit 5. As a result, it is easy to apply the technology according to the present disclosure to an existing processing machine 1. In addition, the criteria for determining whether or not the rotation of the tool 101 has slowed down can be flexibly and easily changed depending on the type of the tool 101 and / or the material of the workpiece 103, etc.

[0154] The modified example of Fig. 7(c) is, simply put, a combination of the modified examples of Fig. 7(a) and Fig. 7(b). That is, the rotation of the tool 101 is directly detected by a non-contact rotation sensor 71A. The detected rotation speed is displayed on a display 73, and the operator can determine whether or not the tool is being decelerated.

[0155] (Modifications related to the spindle rotation method) 8(a) to 8(c) are diagrams showing modified examples of the method of rotating the main shaft 37 in the operation of acquiring the reference position.

[0156] FIG. 8(a) is a schematic diagram of the tool 101 and the workpiece 103 as viewed in the axial direction of the spindle 37 (not shown here).

[0157] In this modification, a fluid is supplied from a nozzle 7A separate from the nozzle 7 that supplies the machining fluid, and the fluid rotates the tool 101. Note that various explanations regarding the nozzle 7 in the description of the embodiment (explanations regarding the nozzle 7 itself, the type of fluid supplied from the nozzle 7, the supply unit for supplying the fluid to the nozzle 7, and the position and direction to which the fluid is applied) may be applied to the nozzle 7A as long as no contradictions arise.

[0158] The configuration of nozzle 7A may be different from or the same as that of nozzle 7. The fluid supplied from nozzle 7A may be a machining fluid or may not be a machining fluid. When the fluid supplied from nozzle 7A is a gas, the supply source that supplies the fluid to nozzle 7A may be an air supply source such as a pump. The fluid supply unit that supplies the fluid to nozzle 7A may be configured completely differently from the fluid supply unit that supplies the fluid to nozzle 7, or they may share a portion of the same configuration. The fluid from nozzle 7A may be supplied toward the machining region like the fluid from nozzle 7, or may be supplied toward a region different from the machining region.

[0159] As described above, the fluid supply unit 9 may have the nozzle 7A that supplies the fluid for rotating the spindle 37, separate from the nozzle 7 that supplies the machining fluid.

[0160] In this case, for example, since the nozzle 7A does not supply fluid for processing, there is a high degree of freedom in terms of the position, orientation, and configuration of the nozzle 7A, as well as the type of fluid supplied from the nozzle 7A, and there are no restrictions as with the nozzle 7. As a result, for example, the fluid supply unit 9 can be configured in a manner suitable for obtaining a reference position.

[0161] FIG. 8(b) is a schematic diagram of the tool 101 and the workpiece 103 as viewed from the side of the spindle 37.

[0162] In this modification, similar to the modification in FIG. 8(a), a nozzle 7B is provided in addition to the nozzle 7. The fluid from the nozzle 7B is applied not to the tool 101 but to the spindle 37 (more specifically, to the outer surface exposed to the outside from the spindle head 35). Unlike the illustrated example, the fluid from the nozzle 7 may be applied to the spindle 37. The various explanations given above, such as the direction of the fluid in the mode in which the fluid is applied to the tool 101, may be applied to the mode in which the fluid is applied to the spindle 37, unless a contradiction arises.

[0163] When a fluid is applied to the spindle 37 as in this modified example, it is expected that fluctuations in the rotation speed when obtaining the reference position will be reduced, for example, when the tool 101 is replaced with a different type of tool, compared to when the fluid is applied to the tool 101.

[0164] FIG. 8(c) is a cross-sectional view corresponding to a part of FIG.

[0165] In this modification, rotation of the main shaft 37 for acquiring the reference position is realized by a hydrostatic bearing (for example, an air bearing) instead of or in addition to the conventional method. Specifically, inside the hydrostatic bearing, a fluid applies pressure to the main shaft 37, and the distribution of this pressure is made unbalanced. This causes the main shaft 37 to rotate. Any appropriate configuration may be used to realize this unbalance.

[0166] In the illustrated example, grooves 77 are formed on the outer surface of spindle 37 at an angle to the axis. Fluid discharged from the hydrostatic bearing to the tip side of spindle 37 passes through the position of grooves 77. This disrupts the balance of pressure applied to spindle 37, and a moment is applied to spindle 37. However, this moment is relatively small, and has little effect on the rotation of spindle 37 during machining.

[0167] Furthermore, for example, although not specifically shown, the imbalance may be achieved by the shape and / or arrangement of a plurality of openings that supply fluid into the hydrostatic bearing. Furthermore, the imbalance may be achieved by opening and closing valves that are individually provided in the flow paths that communicate with the plurality of openings. As can be understood from the above examples, the imbalance may be continuous, occurring even when the reference position is not being acquired, or may be temporary, occurring only when the reference position is being acquired.

[0168] As described above, the processing machine 1 may have an air bearing (bearing 43) that supports the main shaft 37, and a pump 45 that sends air into the bearing 43. The pressure of the air sent into the bearing 43 by the pump 45 may be used to achieve rotation of the main shaft 37 in the operation of obtaining the reference position.

[0169] In this case, for example, compared to a mode in which a fluid is applied to the tool 101 and the tool 101 is rotated, it is expected that fluctuations in the rotation speed when obtaining the reference position will be reduced when the tool 101 is replaced with a different type of tool.

[0170] The technology according to the present disclosure is not limited to the above-described embodiments and may be implemented in various forms.

[0171] In the description of the embodiments, the reference position is the position of the movable part (one of the main shaft and the holder) in the first direction (Z direction) in the absolute coordinate system. However, the reference position may be the relative position of the movable part in the first direction with respect to another member (the other of the main shaft and the holder). In this case, the position sensor that detects the position of the movable part in the first direction may be a single sensor that detects the relative position between the movable part and the other member, or may be a combination of a sensor that detects the absolute position of the movable part and a sensor that detects the absolute position of the other member. [Explanation of symbols]

[0172] 1...machining machine, 3...machine body, 5...control unit, 7...nozzle, 9...fluid supply unit, 25...table (holding unit), 37...main spindle, 39...Z-axis motor (drive unit), 69...Z-axis position sensor (position sensor), 71...rotation sensor, 101...tool, 103...workpiece (reference member).

Claims

1. a spindle that holds one of a tool and a workpiece; a holding portion that holds the other of the tool and the workpiece; a drive unit that moves a movable unit, which is one of the main shaft and the holding unit, in a predetermined first direction; a position sensor that detects the position of the movable part in the first direction; a rotation sensor for detecting rotation of the spindle; a control unit that controls the drive unit based on a detection value of the position sensor so as to move the movable unit to a relative position set with respect to a predetermined reference position in the first direction when the workpiece is machined by the tool while the spindle is rotating; It has When the workpiece or a member that is immovable relative to the workpiece is referred to as a reference member, the control unit acquires, as the reference position, a position detected by the position sensor when a predetermined signal is input in a state in which the rotation of the spindle is detected by the rotation sensor and the movable part moves in the first direction so that the tool and the reference member are in contact with each other in the first direction, When the tool or the workpiece held by the spindle is referred to as a rotation object, The rotation axis of the rotation object is rotated by applying a fluid to the outer surface of the rotation object. processing machine.

2. the tool is a grinding wheel that performs grinding on the outer periphery, The fluid supply unit applies the fluid to the outer periphery in a tangential direction of the outer periphery, thereby realizing rotation of the main shaft in the operation of acquiring the reference position. The processing machine according to claim 1.

3. A spindle that holds one of a tool and a workpiece; a holding portion that holds the other of the tool and the workpiece; a drive unit that moves a movable unit, which is one of the main shaft and the holding unit, in a predetermined first direction; a position sensor that detects the position of the movable part in the first direction; a rotation sensor for detecting rotation of the spindle; a control unit that controls the drive unit based on a detection value of the position sensor so as to move the movable unit to a relative position set with respect to a predetermined reference position in the first direction when the workpiece is machined by the tool while the spindle is rotating; It has When the workpiece or a member that is immovable relative to the workpiece is referred to as a reference member, the control unit acquires, as the reference position, a position detected by the position sensor when a predetermined signal is input in a state in which the rotation of the spindle is detected by the rotation sensor and the movable part moves in the first direction so that the tool and the reference member are in contact with each other in the first direction, The rotation of the spindle in the operation of acquiring the reference position is realized by applying a fluid to an outer surface exposed to the outside of the spindle. processing machine.

4. The fluid supply unit has a nozzle for supplying a machining fluid as the fluid.

3. The processing machine according to claim 1 or 2.

5. The fluid supply unit has a nozzle for supplying the fluid, which is separate from a nozzle for supplying the machining liquid. The processing machine according to any one of claims 1 to 3.

6. A spindle that holds one of a tool and a workpiece; a holding portion that holds the other of the tool and the workpiece; a drive unit that moves a movable unit, which is one of the main shaft and the holding unit, in a predetermined first direction; a position sensor that detects the position of the movable part in the first direction; a rotation sensor for detecting rotation of the spindle; a control unit that controls the drive unit based on a detection value of the position sensor so as to move the movable unit to a relative position set with respect to a predetermined reference position in the first direction when the workpiece is machined by the tool while the spindle is rotating; an air bearing for supporting the main shaft; a pump for feeding air into the air bearing; It has When the workpiece or a member that is immovable relative to the workpiece is referred to as a reference member, the control unit acquires, as the reference position, a position detected by the position sensor when a predetermined signal is input in a state in which the rotation of the spindle is detected by the rotation sensor and the movable part moves in the first direction so that the tool and the reference member are in contact with each other in the first direction, The rotation of the main shaft in the operation of obtaining the reference position is realized by the pressure of the air sent into the air bearing by the pump. processing machine.

7. The predetermined signal is a signal from the rotation sensor corresponding to the deceleration of the rotation of the main shaft. The processing machine according to any one of claims 1 to 6.

8. a display that displays the number of rotations of the spindle detected by the rotation sensor; an input unit that accepts operations by an operator; and The predetermined signal is a signal from the input section. The processing machine according to any one of claims 1 to 6.

9. The first direction is a direction intersecting the rotation axis of the main shaft. The processing machine according to any one of claims 1 to 8.

10. the spindle holds the tool; the holding unit is a table that is located on one side of the spindle in the first direction and holds the workpiece, the tool is a grinding wheel that performs grinding on the outer periphery, The reference position is the position where the outer periphery contacts the workpiece or the table. The processing machine according to claim 9.

11. The rotation sensor is provided in a spindle motor that rotates the spindle. The processing machine according to any one of claims 1 to 10.

12. a detection target is located on the spindle, or on the tool or workpiece held by the spindle, The rotation sensor is a non-contact type that detects the rotation of the spindle based on the detection of the passage of the detection target in the circumferential direction of the spindle. The processing machine according to any one of claims 1 to 10.

13. In the operation of acquiring the reference position, the rotation speed of the spindle immediately before the tool comes into contact with the reference member is lower than the rotation speed of the spindle when the workpiece is machined by the tool. The processing machine according to any one of claims 1 to 12.

14. The rotation speed of the spindle when machining the workpiece is 2000 rpm or more, In the operation of acquiring the reference position, the rotation speed of the spindle immediately before the tool comes into contact with the reference member is 200 rpm or less. The processing machine according to claim 13.

15. In the operation of acquiring the reference position, the rotation speed of the spindle immediately before the tool comes into contact with the reference member is 1 / 10 or less of the rotation speed of the spindle when machining the workpiece. The processing machine according to claim 13 or 14.

16. A method for manufacturing a workpiece, comprising using the processing machine according to any one of claims 1 to 15 to process the workpiece with the tool to obtain the workpiece.

17. a spindle that holds one of a tool and a workpiece; a holding portion that holds the other of the tool and the workpiece; a drive unit that moves a movable unit, which is one of the main shaft and the holding unit, in a predetermined first direction; a position sensor that detects the position of the movable part in the first direction; a rotation sensor for detecting rotation of the spindle; A method for manufacturing a workpiece, comprising: using a processing machine having a tool to process the workpiece to obtain a workpiece; When the workpiece or a member that is immovable relative to the workpiece is referred to as a reference member, a step of moving the movable part in the first direction while the spindle is rotating to bring the tool into contact with the reference member; detecting a deceleration of rotation of the spindle caused by contact between the tool and the reference member based on a detection result by the rotation sensor; acquiring, by the position sensor, a position of the movable part in the first direction when the deceleration is detected; It has The state in which the spindle is rotating in the step of bringing the tool into contact with the reference member is By applying a fluid to the outer surface of the tool or the workpiece held by the spindle, by applying a fluid to the externally exposed surface of the spindle; or The processing machine has an air bearing that supports the spindle and a pump that sends air into the air bearing, and the pressure of the air sent into the air bearing by the pump causes Make it happen A method for manufacturing a workpiece.

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