Imaging devices and machine tools

Abstract

To provide an imaging device for taking an image enabling robust processing, while saving a space.SOLUTION: An imaging device includes: a tool support part for supporting a tool; a light source for emitting light to the tool supported by the tool support part; and an imaging part for taking an image of a projection image of the tool displayed on a projection part with the light emitted from the light source.SELECTED DRAWING: Figure 8

Description

Technical Field

[0001] The present invention relates to an imaging device for imaging a tool.

Background Art

[0002] Machine tools include a turning center that moves a tool relative to a rotating workpiece, a machining center that moves a rotating tool relative to a workpiece, and a machining complex that combines these functions. Machine tools are equipped with a tool changing device called an ATC (Automatic Tool Changer), and a workpiece is machined into a desired shape while exchanging a plurality of types of tools during the machining process. The ATC executes tool change between a tool storage section (such as a magazine) and a tool holding section (such as a spindle).

[0003] In such a machine tool, when there are abnormalities such as defects, breakages, or chip winding on the used tool, the tool (hereinafter also referred to as "defective tool") cannot be used for the next machining as it is. For this reason, a technique has been proposed in which an imaging device for imaging the blade shape before and after using the tool is provided, and it is determined whether the tool is a defective tool based on the imaging images before and after its use (Patent Document 1).

[0004] In tool inspection, for example, illumination is applied from one side of the tool, and the tool is imaged by an imaging unit installed on the other side. By using transmitted illumination, the silhouette of the tool is projected, and the contour of the tool is specified based on the silhouette. If a normal contour shape cannot be obtained, it can be determined that the tool is a defective tool.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] Such imaging devices require the placement of a light source and an imaging unit on opposite sides of the optical axis, flanking the tool. Furthermore, a certain distance (working distance: hereinafter referred to as "WD") must be maintained between the camera, which acts as the imaging unit, and the tool. As a result, the distance between the imaging unit and the light source of the imaging device becomes large, which may cause problems with the installation space in the machine tool. In this regard, it is conceivable to process images of the tool surface captured using bright-field imaging, rather than using transmitted illumination. However, in that case, the amount of image information increases, making robust processing difficult. [Means for solving the problem]

[0007] One aspect of the present invention is an imaging device. This imaging device comprises a tool support section for supporting a tool, a light source for irradiating the tool supported by the tool support section with light, and an imaging unit for capturing a projected image of the tool displayed on a projection section by the light irradiated from the light source. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide an imaging device that captures images capable of robust processing while saving space. [Brief explanation of the drawing]

[0009] [Figure 1] This is a perspective view showing the external appearance of the machine tool according to this embodiment. [Figure 2] This is a side view showing the internal configuration of the tool storage device. [Figure 3] This is a schematic perspective view showing the layout of the containment chamber. [Figure 4] This is a schematic front view showing the area around the boundary between the containment chamber and the processing chamber. [Figure 5] This is a hardware configuration diagram of a machine tool and an image processing device. [Figure 6] This is a functional block diagram of an image processing device. [Figure 7] This diagram schematically illustrates the imaging method for the target tool. [Figure 8] This diagram schematically illustrates the imaging method for the target tool. [Figure 9] This diagram schematically illustrates the imaging method for the target tool. [Figure 10] Examples of actual captured images and image processing are shown. [Figure 11] Examples of actual captured images and image processing are shown. [Figure 12] This is a flowchart illustrating the process of acquiring tool shape data. [Figure 13] This is a flowchart illustrating the tool inspection process. [Figure 14] This diagram schematically illustrates the imaging method for the target tool related to the modified example. [Modes for carrying out the invention]

[0010] One embodiment of the present invention will be described below with reference to the drawings. The machine tool of this embodiment is configured as a machining center that processes a workpiece into a desired shape while appropriately changing the tools.

[0011] Figure 1 is a perspective view showing the external appearance of a machine tool according to an embodiment. When viewing the machine tool 1 from the front, the front-to-back, left-to-right, and up-to-down directions are defined as the Z-axis, X-axis, and Y-axis directions, respectively. The machine tool 1 comprises a machining device 2 and a tool storage device 4. A cover 6 (device housing) is provided to enclose these devices. Inside the cover 6, a machining chamber 8 is provided on the right side when viewed from the front, and a storage chamber 10 is provided on the left side. Machining is performed in the machining chamber 8 by the machining device 2. In the storage chamber 10, multiple tools are stored by the tool storage device 4, and tool changes are performed by an ATC (Automatic Tool Changer) (details will be described later).

[0012] An operation panel 12 is provided on the right side surface of the cover 6. An image processing device 14 is connected to the operation panel 12. The user can remotely monitor the working status of the machine tool 1 by the image processing device 14. The image processing device 14 may be a general laptop PC (Personal Computer) or a tablet computer. In a modification, the image processing device may be configured as an internal device of the processing chamber 8.

[0013] FIG. 2 is a side view showing the internal configuration of the tool storage device 4. This figure corresponds to the left side view of the machine tool 1, but for convenience of explanation, it shows a state where the left side surface of the cover 6 is removed. Also, a part of a magazine (described later) is partially cut away and shown.

[0014] The tool storage device 4 has a disk-shaped magazine 20. A plurality of pots 22 are arranged along the outer peripheral surface of the magazine 20, and each is configured to be able to store a tool T. Each pot 22 supports the tool T coaxially, and a plurality of tools are supported radially around the rotation axis 24 of the magazine 20. In a modification, a chain type or other magazine may be adopted.

[0015] The magazine 20 rotates around the rotation axis 24 and horizontally supports the tool T to be exchanged at its front end position (the right end position in FIG. 2). That is, the pot 22 of the magazine 20 functions as a "tool support part" that supports the tool T to be exchanged (also referred to as "target tool Tx") in a standby state in the storage chamber 10.

[0016] An opening 28 is provided in the partition wall 26 that separates the storage chamber 10 and the processing chamber 8, and a shutter 30 for opening and closing the opening 28 is arranged. Also, an opening and closing mechanism 32 is provided that moves the shutter 30 in the longitudinal direction of the target tool Tx to open and close the opening 28. An ATC 34 is provided in the storage chamber 10. The ATC 34 exchanges the tool T held in a standby state in the storage chamber 10 with the tool T held by a tool spindle (not shown) in the processing chamber 8. The tool exchange is performed with the shutter 30 open.

[0017] The target tool Tx is horizontally supported in the storage chamber 10 as a replacement target. The target tool Tx includes the pre-use tool Tp (described later) immediately before tool replacement and the post-use tool Tu (described later) immediately after tool replacement. In this embodiment, images of the pre-use tool Tp and the post-use tool Tu are captured for the same tool. Based on the comparison of these pre-use tool Tp and post-use tool Tu images, the condition of the post-use tool Tu (whether or not it is a defective tool, etc.) is determined.

[0018] Figure 3 is a schematic perspective view showing the configuration inside the containment chamber 10. Figure 4 is a schematic front view showing the area around the boundary between the containment chamber 10 and the processing chamber 8. As shown in Figure 3, the target tool Tx is supported horizontally in the housing chamber 10. The shutter 30 is driven in the longitudinal direction of the target tool Tx by the opening / closing mechanism 32, opening and closing the opening 28. The "longitudinal direction" of the target tool Tx is the direction along the axis of the pot 22 that supports the target tool Tx in the housing chamber 10, and corresponds to the "Z-axis direction". The "short direction" of the target tool Tx is the direction perpendicular to the longitudinal direction and includes the "X-axis direction" and the "Y-axis direction". The opening / closing mechanism 32 includes a screw feed mechanism 33 and a servo motor 35 that drives it.

[0019] As shown in Figure 4, the ATC 34 is positioned in the space between the target tool Tx and the shutter 30. The ATC 34 comprises a main body 36 containing a motor and an arm 38 attached to the motor's rotation axis. The arm 38 has a symmetrical shape with respect to the rotation axis and has gripping portions 40 at both ends. The gripping portion 40 includes a fixed claw 42 and a movable claw 44. By driving the movable claw 44, a gripping operation by the gripping portion 40 can be achieved.

[0020] The ATC34 is equipped with a translation mechanism that moves the arm 38 in the axial direction and a rotation mechanism that rotates the arm 38 around its axis. The motors include a first motor that drives the translation mechanism and a second motor that drives the rotation mechanism. Since such mechanisms are publicly known, a detailed explanation will be omitted.

[0021] When the ATC34 is not in operation, the longitudinal direction of the arm 38 is oriented vertically, as shown in Figure 4. This allows the ATC34 to be housed in the storage chamber 10 with the shutter 30 closed. When the ATC34 is in operation, the pre-use tool Tp is waiting on one side (the storage chamber 10 side) of the axis of the arm 38, and the post-use tool Tu is waiting on the other side (the machining chamber 8 side). At this time, the shutter 30 is opened.

[0022] When the ATC34 is activated, the arm 38 rotates, causing the pair of gripping parts 40 to grip the tool before use Tp and the tool after use Tu, respectively. At this time, the arm 38 temporarily straddles the opening 28. Furthermore, the translation and rotation mechanisms are driven, causing the tools to be released from and mounted to the pot 22 and the tool spindle 37, thereby achieving tool change. Since the operation of such an ATC is well known, a detailed explanation will be omitted.

[0023] The imaging unit 50 and light source 52 are positioned slightly above the holding position of the target tool Tx. The imaging unit 50 is a camera equipped with an image sensor such as a CMOS (Complementary Metal Oxide Semiconductor) or CCD (Charge-Coupled Device). The imaging unit 50 has a resolution of approximately 1 million pixels (1224 x 1024) and can acquire up to 80 images per second.

[0024] The light source 52 has a laser output unit 54 that outputs a highly directional line laser beam (hereinafter also simply referred to as "laser beam") (details will be described later). The light source 52 is located on the opposite side of the shutter 30 from the target tool Tx supported by the pot 22. The shutter 30 functions as a "projection unit" on which the projection of the target tool Tx by the laser beam emitted from the light source 52 is displayed. The imaging unit 50 is located on the opposite side of the shutter 30 from the target tool Tx and captures the projected image of the target tool Tx displayed on the shutter 30.

[0025] The ATC 34 is positioned between the target tool Tx, which is supported by the pot 22, and the shutter 30. Therefore, the light source 52 is positioned so that the projection of the target tool Tx and the projection of the ATC 34 do not overlap due to the irradiation of the laser light. In this embodiment, the light source 52 is positioned slightly above and to the side of the target tool Tx. On the other hand, the imaging unit 50 is also positioned so that the projected image of the target tool Tx and the image of the target tool Tx itself do not overlap in its field of view. In this embodiment, the imaging unit 50 is positioned above the light source 52 and the target tool Tx.

[0026] The distance between the imaging unit 50 and the shutter 30 (working distance: hereinafter also referred to as "WD") is set so that the projection of the imaging target area Ta (see Figure 3) of the target tool Tx can be captured in a single frame. The imaging target area Ta refers to the part of the target tool Tx that needs to be inspected in order to determine whether or not it is a defective tool (also referred to as the "inspection target area"), and is set in advance. In this embodiment, the imaging target area Ta is set to include at least from the base to the tip of the cutting edge of the target tool Tx. In a modified example, the imaging target area Ta may be from the base end to the tip of the cutting edge of the target tool Tx supported by the pot 22.

[0027] Returning to Figure 3, the housing chamber 10 is provided with a light source drive mechanism 56 for moving the light source 52 in the longitudinal direction of the target tool Tx. The light source drive mechanism 56 includes a feed mechanism 57 and a servo motor 58 that drives it. In this embodiment, the feed mechanism 57 is a screw feed mechanism having a linear guide, but it may be an air cylinder or other feed mechanism. The light source drive mechanism 56 drives the light source 52 (laser output unit 54) to scan the line laser beam in the longitudinal direction of the target tool Tx (details will be described later).

[0028] As shown in Figure 4, the rotation axis Lt of the tool spindle 37, the rotation axis Lx of the ATC 34, the direction of movement of the shutter 30, the direction of movement of the light source 52, and the longitudinal direction of the target tool Tx in the tool change standby position are designed to be parallel to each other (all in the Z direction).

[0029] Although not shown in Figures 3 and 4, it goes without saying that the various structural components of the ATC 34, such as the main body 36, opening / closing mechanism 32, light source drive mechanism 56, and imaging unit 50, are stably fixed to the walls, beams, and other structural elements within the housing chamber 10.

[0030] Figure 5 is a hardware configuration diagram of the machine tool 1 and the image processing device 14. The machine tool 1 includes the machining device 2, tool storage device 4, and ATC 34 described above, as well as a machining control device 60 and an operation control device 62. The machining control device 60 functions as a numerical control device and outputs control signals to the machining device 2 according to the machining program. The machining device 2 drives the tool spindle 37 according to instructions from the machining control device 60 to machine the workpiece. The light source 52 and imaging unit 50 described above constitute the imaging device in the machine tool 1. The image processing device 14 processes the images captured by the imaging unit 50.

[0031] The operation control device 62 includes the operation panel 12 and controls the machining control device 60. The ATC 34 removes a tool from the tool storage device 4 according to the replacement instruction from the machining control device 60 and replaces the used tool Tu held on the tool spindle with the unused tool Tp removed from the tool storage device 4.

[0032] The image processing device 14 primarily performs image processing such as tool shape recognition. As described above, the image processing device 14 may be configured as part of the operation control device 62.

[0033] Figure 6 is a functional block diagram of the image processing device 14. Each component of the image processing device 14 is realized by hardware including a CPU (Central Processing Unit) and various auxiliary processors, memory and storage devices, and wired or wireless communication lines connecting them, as well as software stored in the storage devices that supplies processing instructions to the arithmetic units. The computer program may consist of device drivers, an operating system, various application programs located at a higher layer, and libraries that provide common functions to these programs. The blocks described below represent functional units, not hardware units.

[0034] Furthermore, each component of the operation control device 62 and the processing control device 60 may also be implemented by hardware including a processor or other arithmetic unit, memory or storage devices, wired or wireless communication lines connecting them, and software stored in the storage device that supplies processing instructions to the arithmetic unit. The operation control device 62 and the processing control device 60 may be configured as separate devices from the image processing device 14.

[0035] The image processing device 14 includes a user interface processing unit 70, a data processing unit 72, a data storage unit 74, and a communication unit 76. The user interface processing unit 70 accepts user input and is responsible for processing related to the user interface, such as displaying images and outputting sound. The communication unit 76 is responsible for communication with the operation control device 62. The data processing unit 72 executes various processes based on the data acquired by the user interface processing unit 70 and the data stored in the data storage unit 74. The data processing unit 72 also functions as an interface for the user interface processing unit 70, the data storage unit 74, and the communication unit 76. The data storage unit 74 stores various programs and setting data.

[0036] The user interface processing unit 70 includes an input unit 80 and an output unit 82. The input unit 80 receives input from the user via a hardware device such as a touch panel or handle. The output unit 82 provides the user with various information via image display or audio output. The output unit 82 includes a display unit 84. The display unit 84 displays captured images, displays information related to image processing, and displays information to notify the user of the occurrence of various events.

[0037] The communication unit 76 includes a receiving unit 110 that receives data from the operation control device 62, and a transmitting unit 112 that transmits data and commands to the operation control device 62.

[0038] The data processing unit 72 includes a movement control unit 90, an imaging processing unit 92, a shape reproduction unit 94, a display control unit 95, a tool management unit 96, and a determination processing unit 98. The movement control unit 90 controls the opening and closing of the shutter 30 by driving the opening and closing mechanism 32, and also controls the movement of the light source 52 by driving the light source drive mechanism 56. The imaging processing unit 92 controls the imaging unit 50 to capture the projection of the target tool Tx displayed on the shutter 30. The shape reproduction unit 94 generates "tool shape data," which is data indicating the shape of the target tool Tx, based on the captured image. The display control unit 95 controls the display of the display unit 84. The tool management unit 96 associates the tool ID and tool shape data for each target tool Tx and registers them in the data storage unit 74.

[0039] The determination processing unit 98 determines whether the target tool Tx has any abnormalities such as defects, breakage, or chip entanglement (i.e., whether it is a defective tool) based on the captured image of the target tool Tx or based on the tool shape data. When the determination processing unit 98 determines that there is an abnormality in the target tool Tx, the display control unit 95 displays an alert screen on the display unit 84 to inform the user of this fact. The determination processing unit 98 may also instruct the operation control device 62 to display this fact on the operation panel 12. If the used tool Tu is determined to be a defective tool, the tool management unit 96 associates the information that it is a defective tool with the tool ID and registers it as tool information in the data storage unit 74.

[0040] The data storage unit 74 includes a tool information storage unit 100 and a shape data storage unit 102. The tool information storage unit 100 stores information (tool information) for each tool T stored in the magazine 20, associating it with a tool ID. The tool information includes, for example, information such as the type, shape, size, and length of the tool. It may also include information such as cumulative usage time and cumulative number of uses. The data storage unit 74 also temporarily stores captured images.

[0041] The tool information storage unit 100 updates the tool information each time a tool is changed. If the target tool Tx is determined to be a defective tool as described above, that fact is added to the tool information. The tool management unit 96 prohibits the use of the defective tool T, that is, the replacement of the tool Tp as a pre-use tool by the ATC 34, after that determination.

[0042] The shape data storage unit 102 stores the tool shape data generated by the shape reproduction unit 94 in association with the tool ID. In this embodiment, tool shape data is created before and after tool replacement. Therefore, for each target tool Tx, the tool shape data of the tool Tp before use (hereinafter also referred to as "pre-use tool shape data") and the tool shape data of the tool Tu after use (hereinafter also referred to as "post-use tool shape data") are stored in association with the tool ID. The determination processing unit 98 can determine whether the post-use tool Tu is a defective tool by comparing the pre-use tool shape data and the post-use tool shape data for the same tool.

[0043] Next, we will explain the method for imaging tools. Figures 7 to 9 schematically illustrate the imaging method of the target tool Tx. Figures 9(A) to (C) show the movement process of the light source 52 as viewed from above the target tool Tx.

[0044] As shown in Figure 7, the light source drive mechanism 56 has a guide rail 59 that extends parallel to the target tool Tx. The light source 52 is driven in the longitudinal direction of the target tool Tx by the feed mechanism 57 while being guided by the guide rail 59. Three rows of line lasers la, lb, and lc are output from the laser output unit 54 in parallel to each other in the short direction of the target tool Tx. When these laser beams are shone on the target tool Tx, their projection is displayed on the shutter 30.

[0045] As shown in Figure 8, the image capture unit 50 captures the projected image of the target tool Tx displayed on the shutter 30. Therefore, the light source 52 and the image capture unit 50 are positioned on the opposite side of the shutter 30 from the target tool Tx. If the diameter (tool diameter) of the target tool Tx is d, the distance from the light source 52 to the target tool Tx is L1, and the distance from the target tool Tx to the projection is L2, then the height of the shadow of the target tool Tx on the shutter 30 is h = d × L2 / L1. The image capture unit 50 is set to WD so that the projection image of the target portion of the target tool Tx is within its field of view.

[0046] The imaging unit 50, shown by a dashed line in the figure, represents an example configuration (comparative example) for imaging the silhouette of the target tool Tx using transmitted illumination. The WD of the imaging unit 50 in the comparative example is assumed to be the same as in this embodiment. If this comparative example is adopted, the installation space for the imaging device will require a length of at least L2 + L3, which is larger than that of this embodiment. In other words, this embodiment allows for space savings compared to the comparative example.

[0047] During image processing of the target tool Tx, as shown in Figures 9(A) to (C), the light source 52 is moved in the longitudinal direction of the target tool Tx while continuous imaging is performed by the imaging unit 50 (continuous shooting). The position of the imaging unit 50 remains fixed. Due to the high directivity of the three rows of laser light, three rows of projections are captured instantaneously, but because continuous shooting is performed while the light source 52 is moved, the gaps between those three rows are also obtained as projections in subsequent images (see dashed lines). In other words, a projected image is obtained over the entire area of ​​the imaging target Ta.

[0048] Figures 10 and 11 show examples of actual captured images and image processing. Figures 10(A) to (E) show sequentially obtained captured images (partial images). Figure 11(A) shows the overall image created by combining the partial images. Figure 11(B) shows edge detection in image processing.

[0049] The imaging processing unit 92 extracts the region R where the boundary between light and dark exists, which is the projection portion of the target tool Tx by the laser light, from multiple continuously obtained imaging images as a partial image (Figures 10(A) to (E)). Then, it combines these partial images to generate an overall image P (Figure 11(A)). The imaging processing unit 92 further sets a scan line in the short direction of the target tool Tx in the overall image P and detects points located at the boundary between dark and light regions in the overall image P as edge points. The imaging processing unit 92 detects multiple edge points while shifting the scan line in the long direction of Tx at a constant pitch, and identifies the contour of the target tool Tx by connecting these edge points (Figure 11(B)). The shape reproduction unit 94 generates tool shape data based on the identified contour. In this embodiment, these image processing operations are performed for both the used tool Tu and the new tool Tp.

[0050] The determination processing unit 98 compares pre-use tool shape data with post-use tool shape data for the same tool. When the similarity between the pre-use tool shape and the post-use tool shape, particularly the similarity of the contours, is below a predetermined value, the determination processing unit 98 determines that a defect or other issue has occurred in the target tool Tx, i.e., that the target tool Tx is a defective tool. At this time, the display unit 84 displays an alert screen to the user indicating that a defective tool has been detected. Alternatively, it may generate an audible sound such as a buzzer.

[0051] Figure 12 is a flowchart illustrating the tool shape data acquisition process. This process is performed prior to tool replacement, triggered when the unused tool Tp is held horizontally in a standby state in the storage chamber 10. At this time, the shutter 30 is closed and the light source 52 is in the standby position. The "standby position" here refers to the stopping position near the longitudinal base end of the target tool Tx, and is pre-set so as to include one end of the projection of the imaging target area Ta (the left end in Figure 9).

[0052] Prior to this process, the imaging processing unit 92 turns on a predetermined tool change prohibition flag (S10). This prohibits tool changes by the ATC 34 while the pre-use tool Tp is being imaged. Subsequently, the movement control unit 90 starts moving the light source 52 toward the tool cutting edge (S12), and the imaging processing unit 92 starts imaging (continuous shooting) by the imaging unit 50 (S14). The multiple images acquired at this time are stored as pre-tool use images.

[0053] Then, when the light source 52 reaches the stopping position (Y in S16), the movement control unit 90 stops the movement of the light source 52 (S18), and the imaging processing unit 92 stops imaging by the imaging unit 50 (S20). The "stopping position" here refers to the stopping position near the longitudinal end of the target tool Tx, and is pre-set to include the other end of the projection of the imaging target unit Ta (the right end in Figure 9). The imaging processing unit 92 turns off the tool change prohibition flag (S22). With the completion of this imaging, tool change by the ATC 34 is permitted. In other words, the imaging process for the tool Tp before use is performed while the tool change prohibition flag is on.

[0054] The imaging processing unit 92 extracts and combines partial images containing light and dark boundaries from each of the multiple pre-use tool images described above (S24). This generates the overall image P (see Figure 11(A)). The shape reproduction unit 94 generates pre-use tool shape data based on the overall image P (S26). The tool management unit 96 associates this pre-use tool shape data with the tool ID and stores it in the shape data storage unit 102 (S28). This pre-use tool shape data is used for tool inspection, which will be described later.

[0055] Figure 13 is a flowchart representing the tool inspection process. This process is executed when the used tool Tu is held horizontally in a standby state in the storage chamber 10, prior to the storage of the tool after tool replacement. At this time, the shutter 30 is closed and the light source 52 is in the aforementioned stop position.

[0056] First, the movement control unit 90 starts moving the light source 52 toward the tool base end (S30), and the imaging processing unit 92 starts imaging (continuous shooting) by the imaging unit 50 (S32). The multiple images acquired at this time are stored as post-tool use images.

[0057] Then, when the light source 52 reaches the aforementioned standby position (Y in S34), the movement control unit 90 stops the movement of the light source 52 (S36), and the imaging processing unit 92 stops imaging by the imaging unit 50 (S38). The imaging processing unit 92 extracts and combines partial images where light and dark boundaries exist from each of the multiple post-use tool images (S40). This generates the overall image P. The shape reproduction unit 94 generates post-use tool shape data based on the overall image P (S42). The tool management unit 96 temporarily stores this post-use tool shape data in the shape data storage unit 102, associating it with the tool ID (S44).

[0058] The judgment processing unit 98 reads the pre-use tool shape data with the same tool ID as the post-use tool shape data (S46) and compares the tool shape data (S48). That is, it compares the pre-use tool shape and the post-use tool shape for the same tool. At this time, if the similarity between the post-use tool shape and the pre-use tool shape is less than or equal to a predetermined value, it determines that the tool is defective (Y in S50), and the display unit 84 is notified accordingly (S52). That is, the display unit 84 displays an alert screen. If the tool is not defective (N in S50), the process in S52 is skipped.

[0059] In this embodiment, used tools Tu that are determined to be defective after tool replacement are also stored in magazine 20, but their use is prohibited until predetermined maintenance is performed. Information that the tool is prohibited is stored in association with the tool ID.

[0060] Tools generally have upper limits set for the number of uses and usage time (also called "quality assurance parameters") to ensure their quality. Tools whose quality assurance parameters exceed these upper limits are prohibited from use, and a similar tool (sub-tool) provided separately and stored in magazine 20 is used instead. This prevents disruption to the mass production process by the processing device 2. In this embodiment, even if the quality assurance parameters do not exceed the upper limits, if a defective tool is detected, the tool in question is prohibited from use, and a sub-tool is used.

[0061] The machine tool 1 has been described above based on the embodiment. In this embodiment, the shutter 30, located on the opposite side of the light source 52 from the target tool Tx, is used as the projection unit. The imaging unit 50 then captures the projected image of the target tool Tx projected onto the shutter 30 by the light emitted from the light source 52. Due to this arrangement, even if the imaging unit 50 has a relatively large working width (WD), it does not require a large space in the optical axis direction of the light source 52. Furthermore, because the processing is performed on a projected image, the amount of image information to be processed can be kept to a minimum. In other words, according to this embodiment, robust image processing can be achieved while saving space in the imaging device.

[0062] Furthermore, the target tool Tx is continuously photographed while scanning with multiple rows of line laser beams, acquiring multiple rows of projected images in succession. Therefore, even if there are parts that cannot be captured instantaneously during the camera shutter opening and closing operation time, these can be filled in between the multiple rows of images. In other words, the relationship between the spacing of the multiple rows of line laser beams, the movement speed of the light source 52, and the continuous shooting speed of the imaging unit 50 is set so that these parts can be filled in by multiple partial images. As a result, by combining the partial images, a complete image of the projected image of the target tool Tx without any missing parts can be obtained.

[0063] It should be noted that the present invention is not limited to the embodiments and modifications described above, and the components can be modified and implemented without departing from the spirit of the invention. Various inventions may be formed by appropriately combining the multiple components disclosed in the embodiments and modifications described above. In addition, some components may be deleted from all the components shown in the embodiments and modifications described above.

[0064] [Differentiation] Figure 14 schematically illustrates the imaging method of the target tool Tx related to the modified example. In this modified example, the light source 52 is positioned on the opposite side of the shutter 30 from the target tool Tx, but the imaging unit 50 is positioned on the same side of the shutter 30 from the target tool Tx. Depending on the size of the light drive (WD) of the light source 52, this arrangement may be adopted. Even with this configuration, space savings can be achieved compared to an imaging device using transmitted illumination (comparative example) (see dashed line in Figure 8).

[0065] [Other variations] In the above embodiment, a configuration in which three rows of line laser light are output from the laser output unit 54 is illustrated, but it may also be two rows or four or more rows. It is sufficient to output multiple rows of line laser light and obtain multiple rows of projected images. The image processing unit can generate an overall image by combining all of the captured multiple rows of projected images.

[0066] In the above embodiment, the light source drive mechanism 56 is configured with a feed mechanism 57, and the laser output unit 54 is moved in the longitudinal direction of the target tool Tx to scan the line laser beam while imaging the target tool Tx. In a modified example, the light source drive mechanism may be a so-called swivel mechanism, and the laser output unit 54 may be rotated around a predetermined rotation axis to scan the line laser beam in the longitudinal direction of the target tool Tx.

[0067] In the above embodiment, the laser output unit 54 is moved in the longitudinal direction of the target tool Tx to scan the line laser beam and take multiple images of the target tool Tx, i.e., multiple images are taken. In a modified example, the exposure time of the camera may be extended and an image may be taken only once. However, taking multiple images offers advantages in terms of contrast. The same applies when the light source drive mechanism is a swivel mechanism as in the modified example above.

[0068] In the above embodiment, tool length information is stored in the tool information storage unit 100 in association with the tool ID. Therefore, the movement control unit 90 may read the tool information corresponding to the target tool Tx and change the amount of movement of the light source 52 according to the tool length. In other words, the movement stop position may be set according to the length of the target tool Tx.

[0069] In the above embodiment, a configuration was illustrated in which the determination processing unit 98 determines whether the target tool Tx is defective. In a modified example, the tool shape data generated by the shape reproduction unit 94 for the tool Tp before use and the tool Tu after use may be displayed by the display unit 84 in a comparative manner. The user may then determine whether the target tool Tx is a defective tool by visually comparing the tool shapes before and after use.

[0070] In the above embodiment, images were taken of each target tool Tx before and after tool change (i.e., before and after machining) to generate tool shape data. Then, by comparing the pre-use tool shape data with the post-use tool shape data for each tool, it was determined whether there were any abnormalities such as defects. In a modified example, the tool image itself may be used to determine whether a tool is defective without generating tool shape data (tool contour data). That is, by comparing the pre-use tool image with the post-use tool image for each target tool Tx, it may be determined whether the post-use tool Tu is a defective tool or not.

[0071] In the above embodiment, each target tool Tx was imaged immediately before and immediately after machining, and the state of the tool Tu after use (whether or not it was a defective tool) was determined based on these images. In other words, an example was shown in which the image taken immediately before use was used as a "reference image" and used as the criterion for determination. In a modified example, the reference image may be stored as basic data when the tool is registered before the first use of the tool.

[0072] In the above embodiment, as shown in Figure 8, the imaging unit 50 and the light source 52 are positioned above the target tool Tx. In a modified example, one of the imaging unit 50 and the light source 52 may be positioned above the target tool Tx, and the other below the target tool Tx. Alternatively, the light source 52 may be positioned at the same height as the target tool Tx, and the imaging unit 50 may be positioned above or below the target tool Tx. The only requirement is that the target tool Tx does not interfere with the imaging of the projected image by the imaging unit 50.

[0073] In the above embodiment, the movable shutter 30 was used as the "projection unit," but the target tool Tx may also be projected onto an oil pan, partition plate, side wall, side cover, etc., which are fixed to the device and do not move, as the "projection unit." Alternatively, the target tool Tx may be projected onto a flat surface of the movable robot arm as the "projection unit." In order to accurately detect the edge of the tool in order to detect tool wear, etc., it is preferable that the part of the projection unit on which the shadow of the tool is projected is flat. When using an imaging device for detecting chip entanglement or tool breakage, detection is possible even if the shadow is projected onto a curved surface.

[0074] In the above embodiment, an example was shown in which the "display unit" is provided on the image processing device 14. In a modified example, the display screen of the control panel 12 of the machine tool 1 may be used as the "display unit".

[0075] Although not described in detail in the above embodiment, the line laser beam may have a different wavelength from the lighting in the room where the target tool Tx is placed. The laser output unit 54 may have a bandpass filter function and output line laser beam having a specific wavelength. The line laser beam may be visible light, ultraviolet light, or infrared light.

[0076] In the above embodiment, the pot 22 of the magazine 20 is used as a "tool support unit," and a configuration is shown in which the target tool Tx is supported in a standby state in the storage chamber 10. In a modified example, the ATC 34 (more specifically, the arm 38) may function as a "tool support unit." That is, with the target tool before or after tool change supported by the ATC, the light source 52 may be moved and imaging processing by the imaging unit 50 may be performed.

[0077] In the above embodiment, ATC34 was exemplified as the "tool transport unit," but a tool transport mechanism that transports tools between the processing chamber and the storage chamber may be provided without having a tool changing function.

[0078] In the above embodiment, a machining center was used as an example of machine tool 1, but it goes without saying that the tool inspection technology described above can also be applied to turning centers and multi-tasking machines.

[0079] In the above embodiment, an example was shown where the imaging device is a machine tool 1, but it is not limited to this. For example, the imaging device may be a tool storage device (see Figure 5). If the tool storage device is the imaging device, then, for example, the side walls or other parts that make up the tool storage device become the projection area.

[0080] Although not mentioned in the above embodiment, in the imaging device (see Figure 8), when WD is small, the distance between the imaging unit 50 (see solid line) and the shutter 30 may be shorter than the distance L3 between the imaging unit 50 (see dashed line) and the shutter 30 in the comparative example.

[0081] Furthermore, the angle between the line connecting the center of the target tool Tx and the light source 52, and the line connecting the intersection point of the projection section where the line intersects the aforementioned line and the imaging unit 50, is preferably in the range of 5° to 15°. In addition, the imaging unit 50 may be located in the light irradiation area of ​​the light source 52 (inside the dotted line in Figure 8). [Explanation of symbols]

[0082] 1 Machine tool, 2 Processing device, 4 Tool storage device, 8 Processing chamber, 10 Storage chamber, 12 Control panel, 14 Image processing device, 20 Magazine, 28 Aperture, 30 Shutter, 32 Opening / closing mechanism, 34 ATC, 37 Tool spindle, 50 Imaging unit, 52 Light source, 54 Laser output unit, 56 Light source drive mechanism, 57 Feed mechanism, 58 Servo motor, 59 Guide rail, 60 Processing control device, 62 Operation control device, 70 User interface processing unit, 72 Data processing unit, 74 Data storage unit, 76 Communication unit, 90 Movement control unit, 92 Imaging processing unit, 94 Shape reproduction unit, 96 Tool management unit, 98 Judgment processing unit, P Overall image, PC Laptop, R Area, T Tool, Ta Imaging target unit, Tp Tool before use, Tu Tool after use, Tx Target tool.

Claims

1. A tool support section that supports the tool, A light source that irradiates light onto a tool supported by the tool support portion, A projection section located on the opposite side of the light source to the tool supported by the tool support section, An imaging unit captures a projected image of the tool projected onto the projection unit by light emitted from the light source, An imaging device comprising: a data processing unit that extracts regions where light and dark boundaries exist in the projected image from each of a plurality of captured images obtained by the imaging unit as partial images, combines the partial images to generate a whole image, detects points located at the boundary between dark and light regions as edge points based on scan lines set in the whole image, identifies the contour of the tool by connecting a plurality of edge points, and generates tool shape data based on the identified contour.

2. The imaging device according to Claim 1, The data processing unit compares pre-use tool shape data generated before use and post-use tool shape data generated after use for the same tool, and determines that the tool is defective when the similarity between the two is less than or equal to a predetermined value.

3. A tool support section that supports the tool, The imaging apparatus according to claim 1 or 2, A machine tool comprising: a control unit that, while imaging the tool before use by the imaging device, turns on a tool change prohibition flag to prohibit tool change, and after imaging is complete, turns off the tool change prohibition flag to permit tool change.

Images