Working machinery

Abstract

To install an imaging device for tool inspection in a space-saving manner on a machine tool. [Solution] One embodiment of a machine tool comprises a machining chamber in which workpiece machining is carried out, a tool support unit that supports tools in the machining chamber, a base that is movably arranged in the machining chamber, a work table provided on the base, an imaging unit attached to the base or the work table, an illumination unit that illuminates the tool supported on the tool support unit from the opposite side to the imaging unit, and a movement mechanism that moves the base and changes the position of the imaging unit relative to the tool supported on the tool support unit.

Description

[Technical Field]

[0001] The present invention relates to an apparatus for inspecting a tool used in a machine tool. [Background technology]

[0002] In machine tools such as machining centers and multitasking machines, a workpiece is attached to a table installed in a machining chamber. The workpiece can be machined into the desired shape by moving the table relative to the spindle that holds the rotating tool. These machine tools are equipped with a tool changer called an ATC (Automatic Tool Changer), and workpieces are machined while changing between multiple types of tools during the machining process.

[0003] In such machine tools, if a tool after use has an abnormality such as chipping, breakage, or wrapping of chips, the tool (hereinafter also referred to as a "defective tool") cannot be used for the next machining. For this reason, an imaging device is provided to capture images of the cutting edge shape before and after use of the tool, and tool inspection is performed to determine whether the tool is defective based on the captured images before and after use (Patent Document 1).

[0004] In tool inspection, for example, a tool is illuminated from one side and photographed by a camera installed on the other side. A silhouette of the tool is projected using transmitted light, and the tool's outline is identified based on that silhouette. If a normal outline shape is not obtained, the tool can be determined to be defective.

[0005] Incidentally, in order to capture the entire tool image (for example, from the base to the tip) on one screen, it is necessary to keep the distance between the camera and the tool (working distance) relatively large. However, increasing the working distance increases the image length per pixel, making it difficult to detect fine shapes.

[0006] Therefore, a device has been proposed that is provided with a movement mechanism that moves a camera in the longitudinal direction of a tool, takes images multiple times while moving the camera, and combines the multiple images obtained (Patent Document 2). With this type of imaging device, it is possible to obtain an entire image of the imaging target part regardless of the dimensions of the tool, and this can be used for tool inspection. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-131357 [Patent Document 2] Patent No. 6991375 Summary of the Invention [Problem to be solved by the invention]

[0008] When introducing such an imaging device, it is expected that it will be retrofitted to an existing machine tool. In that case, it is desirable that it does not cause problems with installation space, that is, that it can be realized in a space-saving manner. [Means for solving the problem]

[0009] One aspect of the present invention is a machine tool that includes a machining chamber in which machining of a workpiece is performed, a tool support unit that supports a tool in the machining chamber, a base that is movably arranged in the machining chamber, a work table that is provided on the base, an imaging unit that is attached to the base or the work table, an illumination unit that illuminates the tool supported by the tool support unit from the side opposite to the imaging unit, and a movement mechanism that moves the base to change the position of the imaging unit relative to the tool supported by the tool support unit. [Effects of the Invention]

[0010] According to the present invention, an imaging device for tool inspection can be installed in a space-saving manner in a machine tool. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a perspective view illustrating an appearance of a machine tool according to an embodiment. [Figure 2] FIG. 2 is a hardware configuration diagram of a machine tool and an information processing device. [Figure 3] FIG. 2 is a perspective view illustrating a schematic configuration of a processing device. [Figure 4] FIG. 1 is a perspective view of a machine tool as seen from above. [Figure 5] FIG. 1 is a diagram schematically illustrating a configuration of an imaging device used for tool inspection. [Figure 6] FIG. 2 is a diagram showing the structure of the lighting unit in detail. [Figure 7] FIG. 2 is a diagram showing the structure of the lighting unit in detail. [Figure 8] FIG. 2 is a diagram showing the structure of the lighting unit in detail. [Figure 9] FIG. 2 is a perspective view illustrating an imaging unit and its surrounding structure. [Figure 10] FIG. 2 is a diagram illustrating a structure of an imaging unit. [Figure 11] FIG. 2 is a functional block diagram of the information processing device. [Figure 12] FIG. 10 is a diagram illustrating a method for capturing an image of a tool during tool inspection. [Figure 13] 10 is a flowchart illustrating an outline of a tool shape data acquisition process. DETAILED DESCRIPTION OF THE INVENTION

[0012] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will now be described with reference to the accompanying drawings. The machine tool of this embodiment is configured as a machining center that processes a workpiece into a desired shape while appropriately changing tools.

[0013] 1 is a perspective view showing the appearance of a machine tool according to an embodiment. When machine tool 1 is viewed from the front, the up-down direction, left-right direction, and front-rear direction are defined as the X-axis direction, the Y-axis direction, and the Z-axis direction, respectively. The machine tool 1 includes a processing device 2 and a tool storage device 4. A cover 6 (housing) is provided to cover these devices. Inside the cover 6, a processing chamber 3 is provided on the right side when viewed from the front, and a storage chamber 5 is provided on the left side. Machining is performed in the processing chamber 3 by the processing device 2. In the storage chamber 5, a plurality of tools are stored by the tool storage device 4.

[0014] An operation panel 8 is provided on the right side of the cover 6. An information processing device 100 is connected to the operation panel 8. A user can remotely monitor the working status of the machine tool 1 using the information processing device 100. The information processing device 100 may be a general laptop PC (Personal Computer) or a tablet computer. In a modified example, the functions of the information processing device may be incorporated into the operation panel 8.

[0015] FIG. 2 is a hardware configuration diagram of the machine tool 1 and the information processing device 100. The machine tool 1 includes the above-mentioned processing device 2 and tool storage device 4, as well as a processing control device 102, an operation control device 104, and an ATC 106. The processing control device 102 functions as a numerical control device (NC) and outputs control signals to the processing device 2 in accordance with a processing program. The processing device 2 drives a tool spindle (hereinafter simply referred to as "spindle") in accordance with instructions from the processing control device 102 to process a workpiece.

[0016] The operation control device 104 includes an operation panel 8 and controls the machining control device 102. The ATC 106 takes out a tool from the tool storage device 4 in accordance with an exchange instruction from the machining control device 102, and exchanges a used tool held in the tool spindle with a ready-to-use tool taken out from the tool storage device 4. The information processing device 100 executes various processes including image processing such as tool shape recognition. The information processing device 100 may be configured as a part of the operation control device 104.

[0017] FIG. 3 is a perspective view showing a schematic configuration of the processing device 2. As shown in FIG. The processing device 2 includes a bed 10, a column 12 erected on the bed 10, a spindle head 14 movably mounted on the front side of the column 12, and a table 16 movably mounted on the bed 10. The spindle head 14 has an axis in the horizontal direction (Z-axis direction) and supports a spindle 18 rotatably about that axis. The spindle head 14 incorporates a spindle motor for driving the spindle 18 to rotate. The spindle 18 functions as a "tool support" to which a tool T held in a tool holder 20 can be coaxially attached. A workpiece W is fixed to the table 16.

[0018] A guide rail 22 is provided on the front of the column 12, and a saddle 24 is supported thereon so as to be movable in the Y-axis direction. A guide rail 26 is provided on the front of the saddle 24, and the spindle head 14 is supported thereon so as to be movable in the X-axis direction. The movement of the saddle 24 and the spindle head 14 is achieved by a feed mechanism (not shown) and a servo motor that drives the feed mechanism. This feed mechanism is, for example, a screw feed mechanism using a ball screw. The spindle 18 is movable in the X- and Y-axis directions by driving the spindle head 14 and saddle 24.

[0019] Meanwhile, a guide rail 32 is provided on the upper surface of the bed 10, and a saddle 34 is supported so as to be movable in the Z-axis direction. A table 16 is provided on the saddle 34. A pallet 17 is detachably attached to the table 16, and a workpiece W is placed and fixed on the pallet 17. The saddle 34 functions as a "base" that is movably arranged in the machining chamber 3. The table 16 functions as a "work table" that supports the pallet 17 on which the workpiece W is placed. The movement of the saddle 34 is achieved by a movement mechanism 35 and a servo motor that drives it. The movement mechanism 35 is, for example, a screw feed mechanism using a ball screw, and functions as a "first movement mechanism" that moves the saddle 34 in the longitudinal direction of the tool. The workpiece W is freely movable in the Z-axis direction by driving the saddle 34. In other words, with the above configuration, the relative positions of the workpiece W and the tool T can be adjusted three-dimensionally.

[0020] The table 16 can move in the axial direction of the spindle 18 and can also rotate in a horizontal plane. By driving the table 16 in rotation, the workpiece on the pallet 17 can be rotated. By driving the table 16 in a linear direction, the workpiece W moves closer to or further away from the tool T. In other words, by controlling the rotation and movement of the table 16 and the movement of the spindle 18, the workpiece can be machined into a desired shape.

[0021] An imaging unit 30 is fixed to the saddle 34. The imaging unit 30 includes a camera equipped with an imaging element such as a CCD or CMOS, and captures an image of the tool T when tool inspection is performed. The imaging unit 30 outputs the captured image to the information processing device 100. During tool inspection, the imaging unit 30 moves together with the table 16 in the longitudinal direction of the tool T, and captures an image of the imaging target portion of the tool T during this movement (details will be described later).

[0022] Fig. 4 is a perspective view seen from above of the machine tool 1. Fig. 5 is a diagram schematically showing the configuration of an imaging device used for tool inspection, showing the inside and outside of the machining chamber 3 as seen from the right side. 4, an illumination unit 40 is disposed on the upper surface (ceiling 36 of the machining chamber 3) of the cover 6 of the machine tool 1. The illumination unit 40 has an illumination section 50 that illuminates the tool T from above, and is activated during tool inspection.

[0023] More specifically, a maintenance opening 42 is provided in the ceiling 36, and a ceiling cover 44 is attached to close the opening 42. The lighting unit 40 is attached to the upper surface of the ceiling cover 44. The lighting unit 40 has an LED light as the lighting section 50. This LED light emits parallel light with relatively high directionality downward. An opening 46 is provided in the ceiling cover 44 in an area below the lighting section 50 to allow light from the lighting section 50 to pass through.

[0024] As shown in FIG. 5, the imaging unit 30 is located below the tool T supported by the spindle 18, and the lighting unit 50 is located above it. The lighting unit 50 is located on the opposite side of the tool T from the imaging unit 30. The lighting unit 40 has a movement mechanism 52 that moves the lighting unit 50 parallel to the axis L of the tool T. The movement mechanism 52 includes a linear guide and a feed mechanism. The feed mechanism is driven by a servo motor. The movement mechanism 52 functions as a "second movement mechanism."

[0025] During tool inspection, a first movement mechanism that moves the imaging unit 30 together with the saddle 34 and a second movement mechanism that moves the illumination unit 50 are interlocked. As a result, the imaging unit 30 and the illumination unit 50 are moved parallel to each other while being positioned on opposite sides of the tool T supported by the spindle 18. The imaging unit 30 captures an image of the silhouette of the tool T by utilizing transmitted illumination from the illumination unit 50.

[0026] 6 to 8 are diagrams showing in detail the structure of the lighting unit 40. Fig. 6(A) is a perspective view seen from above, and Fig. 6(B) is a perspective view showing the internal structure. As shown in Fig. 6(A), the lighting unit 40 is configured by accommodating a movement mechanism 52 in a roughly rectangular parallelepiped case 54. The case 54 has a base member 56 that forms the bottom surface, and a cover 58 attached to the base member 56. An opening 60 for maintenance is provided on the top surface of the cover 58, and is closed by a lid 62. A cable gland 64 is attached to the side of the cover 58 for pulling out a power cable.

[0027] As shown in FIG. 6(B), the movement mechanism 52 is composed of a linear guide 66. The linear guide 66 is provided on the base member 56. The linear guide 66 includes a rail 68 extending in the longitudinal direction of the base member 56 and a carriage 70 slidably attached to the rail 68. The illumination unit 50 is supported facing downward by the carriage 70. The base member 56 is provided with a feed mechanism constituting the movement mechanism 52 and a motor 72 for driving the feed mechanism. In this embodiment, the feed mechanism is a belt-driven feed mechanism, but it may also be a screw feed mechanism or other feed mechanism. The power cable connected to the illumination unit 50 is housed in a cable carrier 74 (protective tube) and is drawn out from a cable gland 64 (FIG. 6(A)). The base member 56 is provided with an opening 46 extending parallel to the rail 68. The opening 46 is rectangular in plan view and closed by glass 76. The glass 76 is tempered glass.

[0028] 7(A) is a side view of the lighting unit 40. FIGS. 7(B) and 7(C) are diagrams illustrating the operation of the lighting unit 40. As shown in Figure 7(A), the glass 76 is attached from below the base member 56. As also shown in Figure 7(B), the lighting unit 50 always faces the glass 76 and moves in the extension direction of the glass 76 (horizontal direction: Z-axis direction) by the drive of the linear guide 66. At this time, the cable carrier 74 deforms to protect the power cable. Light emitted from the lighting unit 50 passes through the glass 76 and is guided downward.

[0029] Fig. 8(A) is a perspective view of the lighting unit 40 as seen from below, and Fig. 8(B) is a cross-sectional view taken along the line AA in Fig. 7(A). 8(A), the opening 46 of the base member 56 is closed by a lid 78 that is rectangular in plan view. The glass 76 constitutes the lid 78. The peripheral edge of the lid 78 is screwed to the base member 56.

[0030] As shown in FIG. 8(B), the glass 76 is sandwiched between an annular plate 80 and an annular pressing member 82 at its periphery, forming a lid 78. The pressing member 82 has a recess (step) that is complementary in shape to the glass 76. The glass 76 is attached to the pressing member 82 so that it fits into the recess. A flange 82a is provided at the top end of the lid 78, protruding outward from the recess. The top surface of the flange 82a and the top surface of the glass 76 are substantially flush with each other. The plate 80 is attached from above.

[0031] The peripheral edge of plate 80 and the peripheral edge of pressing member 82 overlap and are fastened together to base member 56 with screws 83. Sealing gaskets 84a to 84c are interposed between the peripheral edge of the lower surface of glass 76 and pressing member 82, between the peripheral edge of the upper surface of glass 76 and plate 80, and between plate 80 and base member 56. As shown in the figure, the openings of plate 80 and pressing member 82 are large, so most of glass 76 is exposed in lid 78.

[0032] FIG. 9 is a perspective view showing the imaging unit 30 and its surrounding structure. The imaging unit 30 is detachably attached to a saddle 34 that supports the table 16. The saddle 34 is rectangular in plan view, with the table 16 attached to its center. The saddle 34 has a rotation mechanism directly below the table 16, and supports the table 16 rotatably about an axis L1 that extends in the vertical direction (Z-axis direction). The rotation mechanism is realized by, for example, a spindle motor.

[0033] A pallet 17 is removably attached to the table 16, and a workpiece is fixed to the pallet 17. By preparing multiple pallets 17 with workpieces fixed to them, the workpiece can be changed by changing the pallet 17, thereby improving time efficiency.

[0034] The imaging unit 30 is attached to a corner of the saddle 34, spaced apart from the table 16. A mounting hole 86 is provided on the upper surface of the corner of the saddle 34, and the lower part of the imaging unit 30 is inserted coaxially into the mounting hole 86. The imaging unit 30 is fixed to the saddle 34 so that the optical axis of the camera faces upward.

[0035] 10A and 10B are diagrams illustrating the structure of the imaging unit 30. Fig. 10A is a perspective view, and Fig. 10B is a cross-sectional view. As shown in FIG. 10(A), the imaging unit 30 has a sub-illumination unit 92 that is provided integrally with the camera 90. The camera 90 has a stepped cylindrical main body 94, and a lens cover 96 is provided at the upper end of the main body 94. The lens cover 96 is attached to the main body 94 via a hinge and opens or closes the light receiving surface of the camera 90. A small-diameter mounting portion 98 is provided at the lower end of the main body 94. The mounting portion 98 is coaxially inserted into the mounting hole 86, thereby fixing the imaging unit 30 to the saddle 34 (see FIG. 9).

[0036] The secondary illumination unit 92 is supported by a support portion 110 that extends radially outward from the side surface of the main body 94. The secondary illumination unit 92 is used when imaging the tool T in a bright field, and illuminates the imaging target portion of the tool T from below. However, imaging in a bright field generates a large amount of image information, making robust processing difficult, and therefore is only performed when, for example, observing the cutting edge of the tool T.

[0037] 10(B), the camera 90 has an image sensor 112, a telecentric lens 114, a shutter 116, and the like inside the main body 94. The optical axis L2 of the camera 90 coincides with the axis of the main body 94. When imaging in a bright field, the position of the saddle 34 is controlled so that the optical axis L2 of the camera 90 and the optical axis L3 of the secondary illumination unit 92 are directed toward the portion of the tool T to be imaged.

[0038] The shutter 116 operates in a direction perpendicular to the optical axis L2. In this embodiment, the shutter 116 is driven by an air cylinder, but it goes without saying that other driving means may also be used.

[0039] FIG. 11 is a functional block diagram of the information processing device 100. The components of the information processing device 100 are realized by hardware including arithmetic units such as a CPU (Central Processing Unit) and various computer processors, storage devices such as memory and storage, and wired or wireless communication lines connecting them, as well as software stored in the storage devices and supplying processing instructions to the arithmetic units. The computer programs may be configured by device drivers, an operating system, various application programs located at higher levels, and libraries that provide common functions to these programs. Each block described below represents a functional block, not a hardware configuration.

[0040] The information processing device 100 includes a user interface processing unit 120 , a data processing unit 122 , a data storage unit 124 , and a communication unit 126 . The user interface processing unit 120 accepts operations from the user and is responsible for processing related to the user interface, such as image display and audio output. The communication unit 126 is responsible for communication with the operation control device 104. The data processing unit 122 executes various processes based on data acquired by the user interface processing unit 120 and data stored in the data storage unit 124. The data processing unit 122 also functions as an interface between the user interface processing unit 120, the data storage unit 124, and the communication unit 126. The data storage unit 124 stores various programs and setting data.

[0041] The user interface processing unit 120 includes an input unit 130 and an output unit 132 . The input unit 130 accepts input from the user via a hardware device such as a touch panel or a steering wheel. The output unit 132 provides various information to the user via image display or audio output. The output unit 132 includes a display unit 134. When a predetermined abnormal condition is met, such as an abnormality in the tool to be replaced (detection of a defective tool), the display unit 134 displays (notifies) that fact on a display device (not shown).

[0042] The communication unit 126 includes a receiving unit 140 that receives data from the operation control device 104 and a transmitting unit 142 that transmits data and commands to the operation control device 104 .

[0043] The data processing unit 122 includes a movement control unit 150 , an image capturing processing unit 152 , a shape reproducing unit 154 , a tool management unit 156 , and a determination processing unit 158 ​​. The movement control unit 150 drives the feed mechanism to control the movement of the saddle 24 and the spindle head 14 (i.e., the position of the tool T). The movement control unit 150 also drives the movement mechanism 35 to control the movement of the imaging unit 30 (i.e., the position of the imaging unit 30). The movement control unit 150 also drives the movement mechanism 52 to control the movement of the illumination unit 50 (i.e., the position of the illumination unit 50). That is, it controls the respective positions of the imaging unit 30 and the illumination unit 50 with respect to the tool T supported by the spindle 18, and the relative positions of the imaging unit 30 and the illumination unit 50. The imaging processing unit 152 controls the imaging unit 30 to capture an image of the tool T. The shape reproduction unit 154 generates "tool shape data," which is data indicating the shape of the tool T, based on the captured image. The tool management unit 156 associates a tool ID with tool shape data for each tool T and registers them in the data storage unit 124.

[0044] The determination processing unit 158 ​​determines whether the tool T has an abnormality such as chipping, breakage, or wrapping of chips (whether the tool T is a defective tool) based on the captured image of the tool T or based on the tool shape data. When the determination processing unit 158 ​​determines that the tool T is abnormal, the display unit 134 displays that fact on the display device. The determination processing unit 158 ​​may also instruct the operation control device 104 to display that fact on the operation panel 8. When the used tool T is determined to be a defective tool, the tool management unit 156 associates information that the tool is a defective tool with the tool ID and registers it as tool information in the data storage unit 124.

[0045] The data storage unit 124 includes a tool information storage unit 160 and a shape data storage unit 162. The tool information storage unit 160 stores information (tool information) about each tool T stored in the tool storage device 4 in association with a tool ID. The tool information includes, for example, information about the type, shape, size, and length of the tool. It may also include information about the cumulative usage time and cumulative number of uses. The data storage unit 124 also temporarily stores captured images.

[0046] The tool information storage unit 160 updates the tool information each time a tool is replaced. If the tool T is determined to be a defective tool as described above, the tool information storage unit 160 adds a corresponding notification to the tool information. After the determination, the tool management unit 156 prohibits the use of the defective tool T, i.e., prohibits the ATC 106 from selecting the defective tool T for replacement.

[0047] The shape data storage unit 162 stores the tool shape data generated by the shape reproduction unit 154 in association with the tool ID. In this embodiment, tool shape data is created before and after tool replacement. Therefore, for each tool T, tool shape data of the tool T before use (hereinafter also referred to as "pre-use tool shape data") and tool shape data of the used tool T (hereinafter also referred to as "used tool shape data") are stored in association with the tool ID. The determination processing unit 158 ​​can determine whether the used tool T is a defective tool by comparing the pre-use tool shape data and the used tool shape data for the same tool.

[0048] Next, a method for capturing an image of a tool will be described. FIG. 12 is a diagram showing a method for capturing an image of a tool during tool inspection. In this embodiment, the imaging target portion is the portion of the tool T from the base end supported by the spindle 18 to the cutting edge. Therefore, as shown in the figure, when the tool T becomes long to a certain extent, the imaging unit 30 is moved parallel to the axis L of the tool T to capture images multiple times, and the captured images are combined to recognize the overall shape of the imaging target portion. In the example shown in the figure, three images are captured.

[0049] Specifically, while the position of the tool T is fixed at a predetermined inspection position, the imaging unit 30 and the illumination unit 50 are moved to sequentially capture a first image P1 including the tip of the tool T, a second image P2 including the center of the tool T, and a third image P3 including the base end of the tool T. The obtained images are silhouette images of the tool T obtained by transmitted illumination. The movement control unit 150 links the movement mechanism 35 and the movement mechanism 52 to move the imaging unit 30 and the illumination unit 50 so that the optical axis L2 of the imaging unit 30 and the optical axis L4 of the illumination unit 50 coincide with each other. In this embodiment, the movement of the imaging unit 30 and the illumination unit 50 is temporarily stopped after each image capture.

[0050] More specifically, the imaging positions are set so that the images slightly overlap in the longitudinal direction of the tool T, so that the boundaries between the multiple images are smoothly connected when they are combined. The imaging processing unit 152 extracts partial images with sufficiently high contrast from each of the first image P1, the second image P2, and the third image P3, and combines the extracted partial images to generate an overall image of the tool T.

[0051] Specifically, the silhouette of the tool T projected by the illumination unit 50 is displayed as the entire image of the imaging target area. The imaging processing unit 152 sets a scanning line in the Y-axis direction and detects points located on the boundary between a dark area (silhouette area where the tool T exists) and a bright area (area where the tool T does not exist) as edge points. The imaging processing unit 152 detects multiple edge points while shifting the scanning line at a constant pitch in the Z-axis direction, and identifies the contour of the tool T by connecting these edge points. The shape reproduction unit 154 generates tool shape data based on the identified contour.

[0052] FIG. 13 is a flowchart showing an outline of the tool shape data acquisition process. When acquiring shape data of the tool T to be inspected, the movement control unit 150 drives the feed mechanism to move the tool T to the inspection position (S10). Also, it drives the movement mechanisms 35, 52 to move the imaging unit 30 and the illumination unit 50 to the imaging start position (S12). At this time, the imaging unit 30 and the illumination unit 50 are positioned on opposite sides of the tool T.

[0053] Then, with the tool T illuminated by the illumination unit 50 (S14), the imaging processing unit 152 images the tool T using the imaging unit 30 (S16). The image acquired at this time is stored as a first image P1. Subsequently, the movement control unit 150 moves the imaging unit 30 and the illumination unit 50 to the next imaging position (S18), and then the imaging processing unit 152 images the tool T (S20).

[0054] When the preset number of images (three in this embodiment) have been captured (Y in S22), the image capturing processing unit 152 generates an overall image by combining the above-mentioned multiple images P1 to P3 (S24). The shape reproducing unit 154 generates tool shape data based on the overall image (S26). The tool management unit 156 associates this tool shape data with the tool ID and stores it in the shape data storage unit 162 (S28).

[0055] The generation of tool shape data as described above is performed for both the pre-use tool and the used tool. The determination processing unit 158 ​​compares the pre-use tool shape data with the used tool shape data for the same tool. When the similarity between the pre-use tool shape and the used tool shape, particularly the similarity of the contours, is equal to or less than a predetermined value, the determination processing unit 158 ​​determines that the tool T has a defect or the like, that is, that the tool T has become a defective tool.

[0056] The machine tool has been described above based on the embodiment. In this embodiment, the imaging unit 30 used for tool inspection is attached to a saddle 34 and configured to be movable integrally with the table 16. The saddle 34, together with the table 16, is an existing component of the machine tool 1 as a "workpiece holding unit," and the imaging unit 30 is attached by utilizing the free space in the saddle 34. The movement mechanism 35 of the table 16 can be used as is as the movement mechanism for the imaging unit 30, so it can be realized in a space-saving manner.

[0057] In addition, since the lighting unit 50 and its movement mechanism 52 are located above the ceiling 36 (in the attic), there is no need to secure additional space in the machining chamber 3. Furthermore, since tool inspection can be performed in the machining chamber 3, there is no need to provide space for tool inspection in the accommodation chamber 5 of the tool storage device 4. These points also contribute to space saving within the machine tool 1.

[0058] [Variations] In the above embodiment, the machine tool 1 has been described as a machining center, but it may also be a multi-tasking machine that combines the functions of turning and additive machining. Additive machining is a technology (additive manufacturing) that processes an object by melting material powder with a laser.

[0059] In the above embodiment, an example has been shown in which the imaging unit 30 and the illumination unit 50 are moved in the longitudinal direction of the tool T to inspect the entire cutting edge of the tool T. In a modified example, for example, when precisely inspecting the tip shape of the tool, the inspection area may be limited to a small area. In this case, the imaging unit and the illumination unit may be moved in the lateral direction (radial direction) of the tool to acquire an image. In this case, it may be effective to select illumination with higher directionality.

[0060] In the above embodiment, in order to increase the contrast of the captured image, a highly directional LED light is used as the lighting unit 50, and the lighting unit 50 is moved parallel to the tool T. When a light with a large illumination angle is used as the lighting unit, the lighting unit may be fixed.

[0061] In the above embodiment, a configuration has been exemplified in which the imaging unit 30 is positioned below and the illumination unit 50 is positioned above the tool T supported by the spindle 18 during tool inspection. In a modified example, the imaging unit and the illumination unit may be arranged so as to horizontally sandwich the tool T supported by the spindle 18. For example, the imaging unit may be arranged at a predetermined height position in the workpiece holder, and the illumination unit and its movement mechanism may be arranged on the back side (outside the machining chamber 3) of the device housing (cover). In this case, the imaging unit and the illumination unit are moved parallel to the tool so that their optical axes are aligned.

[0062] In the above embodiment, an example has been shown in which the imaging unit 30 and the illumination unit 50 are stopped for each image capture. In a modified example, images may be captured while both the imaging unit and the illumination unit are moving. Images may be captured while both the imaging unit and the illumination unit are stopped at the imaging start position and the final imaging position, and then captured while both are moving at intermediate positions. Whether or not to move may be switched depending on the length of the tool, such as by moving both the imaging unit and the illumination unit when the tool length is equal to or greater than a predetermined value.

[0063] In the above embodiment, the imaging unit 30 is attached to the saddle 34 that supports the table 16. In a modified example, the imaging unit may be attached to a table (work table) that is supported by the saddle.

[0064] In the above embodiment, an example has been shown in which the lighting section 50 and its moving mechanism 52 are installed above the ceiling of the processing chamber 3. In a modified example, these may be installed inside the processing chamber 3. The lighting unit 40 may be installed on the inner wall of the ceiling 36.

[0065] In the above embodiment, the glass 76 that closes the opening of the lighting unit 40 is tempered glass, but it may also be ordinary float glass (plate glass). Alternatively, a transparent acrylic plate may be used. Considering breakage and damage caused by flying chips, etc., tempered glass is preferable.

[0066] The present invention is not limited to the above-described embodiments and modifications, and the components can be modified without departing from the spirit of the invention. Various inventions can be formed by appropriately combining multiple components disclosed in the above-described embodiments and modifications. Furthermore, some components can be omitted from all the components shown in the above-described embodiments and modifications. [Explanation of symbols]

[0067] REFERENCE SIGNS LIST 1 machine tool, 2 machining device, 3 machining chamber, 4 tool storage device, 6 cover, 14 spindle head, 16 table, 18 spindle, 20 tool holder, 30 imaging unit, 34 saddle, 35 moving mechanism, 36 ceiling, 40 lighting unit, 46 opening, 50 lighting unit, 52 moving mechanism, 56 base member, 58 cover, 66 linear guide, 68 rail, 70 carriage, 72 motor, 76 glass, 78 lid body, 80 plate, 82 holding member, 86 mounting hole, 90 camera, 92 auxiliary lighting unit, 96 lens cover, 98 mounting unit, 100 information processing device, 102 machining control device, 104 operation control device, 122 data processing unit, 124 data storage unit, 150 movement control unit, 152 imaging processing unit, 158 judgment processing unit, P1 first image, P2 2nd image, P3 3rd image, T tool, W workpiece.

Claims

1. a machining chamber in which machining of the workpiece is performed; a tool support portion that supports a tool in the processing chamber; a base movably disposed in the processing chamber; a work table provided on the base; an imaging unit attached to the base or the work table; an illumination unit that illuminates the tool supported by the tool support unit from the side opposite to the imaging unit; a first moving mechanism that moves the base to change the position of the imaging unit relative to the tool supported by the tool support unit; a second movement mechanism that moves the illumination unit and changes the position of the illumination unit relative to the tool supported by the tool support unit, The machine tool further comprises: a first moving mechanism and a second moving mechanism that are linked together to move the imaging unit and the illumination unit in parallel while positioning them on opposite sides of the tool supported by the tool support unit.

2. The machine tool according to claim 1 , wherein the workpiece is machined by moving the base and the tool support portion relative to each other.

3. the imaging unit is located below the tool supported by the tool support unit, The machine tool according to claim 1 or 2, wherein the illumination unit is positioned above a tool supported by the tool support unit.

4. 4. The machine tool according to claim 3, wherein the lighting unit is installed above the ceiling of the machining chamber and transmits illumination through an opening provided in the ceiling.

5. the opening extends parallel to an axis of a tool supported by the tool support portion, The machine tool according to claim 4 , wherein the illumination unit moves in the longitudinal direction of the opening.

6. The opening is closed by tempered glass, The machine tool according to claim 5 , wherein the lighting unit is disposed above the tempered glass.

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