JP5945132B2 - Lathe with machining status display device - Google Patents

Description

The present invention relates to a lathe, and more particularly to a lathe including a device that displays a state in which a tool is machining a workpiece on a display and a plurality of tool rests .

  A machine tool that performs workpiece removal processing such as cutting processing is usually performed while supplying a cutting fluid for the purpose of cooling the processing portion and lubricating the tool edge. Further, the removal process generates chips due to the nature of the process. In order to prevent the cutting fluid and chips from splashing around and contaminating the machine itself or deteriorating the surrounding environment, the machining space of the machine tool (the movement space of the tool when machining the workpiece) is usually used. Is surrounded by a partition wall or door to prevent the scattering of cutting fluid and chips. Depending on the type of workpiece and processing, the entire door may be made of a transparent plate. Usually, a transparent window is provided on the door made of iron plate so that the operator can visually recognize the processing space.

  During continuous automatic operation of the NC machine tool, there is almost no need for the operator to visually recognize the machining space. However, when performing test machining for confirming the machining program or when the operator manually performs machining, it is necessary to perform machining while visually checking the machining state. In such a case, the operator sees the machining state from a window provided on the door, and it is necessary to perform confirmation and operation while alternately viewing the display on the operation panel and the machining space. Depending on the viewing direction, it may be necessary to go close to the window to see the machining state. In addition, when the machining state cannot be seen from the window, it is necessary to open the door for confirmation, and it is dangerous to look into the door as the work is complicated.

  On the other hand, a machine tool that can observe the machining state with the door closed by installing a camera for observing the machining state in the machining space and displaying the image of this camera on the display of the operation panel is provided. ing. In this case, the camera direction, focal length, zoom magnification, and the like are manually operated from the operation panel. Also, in a machine tool equipped with such a camera, the operating state of multiple machine tools can be confirmed at a location away from the installation location by displaying the camera image on the display of the management computer via the Internet or the like. You can also perform maintenance.

  The windows provided on the doors are exposed to high-temperature chips and cutting fluids, especially in the case of machine tools that perform metal processing, so the position and area are limited due to problems of strength and aging, and machining through the windows. The visibility of the part is not good. For this reason, the machined part cannot be seen from the required direction in many cases. Check the state of the tool in the machined part (breakage, wrapping of chips, etc.), contact confirmation between the tool and workpiece, and the state of chip accumulation in each part of the machine. You may need to open the door to confirm.

  Furthermore, at the time of workpiece test processing and setup of the machine before processing, it is necessary for the operator to check the positional relationship and movement of workpieces, tools, jigs used for processing, etc. while manually operating the machine with the operation panel. In many cases, the doors are often opened to look inside, so that the workability is poor and the burden on the operator is large.

  In addition, with conventional machine tools with a camera installed in the machining space, the zoom magnification must be manually operated when observing the machining area in detail. The camera's field of view is blocked by the workpiece or the tool post. Cannot be visually recognized, the camera direction and focal length must be adjusted each time the processing part moves, and the processing part moves off the camera screen because it is difficult to follow the moving processing part. In addition, there are problems such as difficulty in continuous observation.

This invention requires an operation for tracking a moving processing part without moving an operator or opening a door during a test process or manual operation in a lathe equipped with a plurality of tool rests. However, it is an object of the present invention to provide a lathe capable of observing the machining portion with a display provided on the operation panel.

In this invention , a plurality of cameras 1 (1a to 1d) are installed in a machining space of a lathe equipped with a plurality of tool rests, and the machining part T of the workpiece 3 by the tool 2 (2a to 2c) is automatically set in these cameras. manner is tracked, Ru display the image which the camera is acquired control panel display. On the operation panel display, along with the images acquired by the camera 1, the corresponding parts and blocks of the machining program and the machine setting status are displayed at the same time, making it easy to check the machine setup, machining program, and machine status. Can be done.

The automatic tracking of the processing part T by the camera 1 does not recognize the processing part T from the image of the camera and automatically track it, but the direction, focal length, zoom magnification, etc. of each camera 1 are shown in the tool rest 4 (4a To 4c) by synchronizing with the movement of the tool edge. That is, using the fact that the position T of the tool cutting edge of each turret is controlled by the NC device, the coordinate signal sent from the NC device to each turret 4 is converted into the direction of the camera or the image clipping region, The camera 1 tracks the processing portion T by converting into command signals of actuators for adjusting the focal length and zoom magnification and driving these actuators . In a lathe equipped with a plurality of turrets, different coordinate signals are sent from the NC unit to each turret, and the tool to be tracked by each camera depends on which turret coordinate signal is given to which camera actuator. You can choose.

Since a tool to be tracked by each camera can be selected for a plurality of cameras, the camera for displaying an image on the display is switched depending on the type of the tool 2 used for machining, the direction of the tool blade edge, the feed direction of the tool post 4, and the like. In addition, it is possible to prevent the line of sight b of the camera 1 toward the processing portion T from being blocked by the workpiece itself or the tool post. . When an alarm occurs in the machine, the image is switched to the machining part of the tool post that is generating. Further , the camera 1 is switched at a necessary timing or manually in accordance with the progress of processing. Usually, it is preferable to install a larger number of cameras than the number of tool rests 4.

  For example, in a two-spindle opposed lathe in which the tool post 4 is arranged above and below the spindle axis a, the cutting parts of the workpiece gripped by the left and right spindles can be viewed from above and below the spindle axis a. Four cameras 1 are arranged. These cameras 1 are provided so as to be movable in the Z-axis direction, for example, if necessary.

  The field of view of each camera 1 can be changed by changing the zoom magnification. For example, the size of the tool and workpiece can be recognized by the NC device, such as the wide-angle side for large workpieces and large tools, and the telephoto side for small workpieces and small tools, and can be automatically set accordingly. it can. Enable manual selection step by step.

  Since the field of view when the camera 1 is tracking the processing portion T varies depending on the distance between the camera 1 and the processing portion T, it is preferable to track the field of view while keeping the field of view constant. This can be realized by automatically changing the zoom magnification according to the distance between the camera 1 and the processing portion T.

  According to the present invention, an operator can display an image most desired to be viewed only by performing an operation of selecting a camera for displaying an image on a display as required, and the image is processed. In addition to automatically tracking the processing portion as the camera progresses and keeping the processing portion in focus accurately, the zoom magnification can also be automatically adjusted to keep the size of the photographing area constant.

  This eliminates the need for the operator to open the door and look into the processing section, and by properly selecting the installation location of multiple cameras, the operator can also view images of the processing section from a position that cannot be seen with the naked eye. You can see it.

  Therefore, according to this invention, the state of the machine that cannot be confirmed from the window provided in the door, such as the state of the tool, the state of wrapping of the chip, the state of contact between the tool and the workpiece, the state of accumulation of the chip in each part of the machining space, etc. The image can be viewed on the display of the panel, and the zoom magnification and the contrast can be adjusted so that the image can be viewed more easily and the operation switch of the operation panel is operated.

In addition, it is possible to automatically select the camera display position, focal length, zoom magnification, and cameras with multiple cameras, making it easy to check the actual position of the tool when checking the machining program. When testing a workpiece or setting up a machine, the operator must not move or open the door, and operate the operation panel in a posture, The state can be confirmed while comparing the image displayed on the display of the operation panel with the block of the machining program, and the workability can be greatly improved.

Top view schematically showing the arrangement of the camera Side view Schematic diagram showing machining of both ends of the workpiece Plan view showing the positional relationship between the camera and the processing part Side view Same perspective view Schematic diagram showing camera image and cutout area Block diagram showing an example of a machining status display device

  Next, an embodiment of the present invention will be described by taking as an example a lathe provided with two opposed spindles and a tool post on both sides of the spindle axis. FIGS. 1 and 2 are a schematic plan view (view of the upper surface of the bed as viewed from above) and a side view showing the arrangement of cameras in an example of such a lathe. The spindles 6a and 6b are provided on both sides of the spindle axis a with the chucks 5a and 5b facing each other, and two turrets 4a, 4b and 4c are provided on the lower side and one on the upper side of the spindle axis a. ing. One of the headstock 6b can be moved and positioned in the spindle axis direction (left and right direction in the figure, Z-axis direction). The lower tool post 4a, 4b is shown as a turret tool post, and the upper tool post 4c is shown as a tool post to which a rotary tool is attached. The turret tool rests 4a and 4b can be moved and positioned in the Z-axis direction and the cutting direction of the tools 2a and 2b (vertical direction in the figure, X-axis direction). The rotary tool turret 4c can be moved and positioned in the Z-axis, the X-axis, and the Y-axis direction orthogonal to the two axes, and can turn around the Y-axis (B-axis direction).

  In the two-spindle facing lathe, both the left end surface 3a and the right end surface 3b of the workpiece 3 are machined as shown in FIG. When one camera is installed on each of the lower side and the upper side of the spindle axis a and the machining part is photographed, the machining part cannot be photographed due to the shadow of the workpiece itself. Therefore, a total of four cameras 1a to 1d are provided, one each on the top, bottom, left and right. The lower cameras 1a and 1b are cameras for photographing the processing parts of the lower tool rests 4a and 4b, and the upper cameras 4c and 4d are cameras for photographing the processing parts of the upper tool rest 4c. As shown in FIG. 2, the camera 1 is provided above the tool rest 4 (at a position away from the bed surface) so that the optical axis (line of sight) b directed to the main axis axis a is not blocked by the tool rest 4. Yes.

  Each camera 1 passes through the camera center (the center of the imaging surface of the image sensor) C, and can control the rotation angle φ about the axis s orthogonal to the plane including the center C and the main axis axis a, respectively. It is installed. Specifically, each camera 1 is mounted on a camera base 11 provided to be rotatable about an axis s, and an actuator (such as a motor) that sets a rotation angle φ around the axis s of the camera base according to a control signal. Is provided. Each camera 1 includes a focal length setting unit that sets a focal length based on a control signal and a zoom magnification setting unit that sets a zoom magnification based on a control signal. Since the focal length setting means and the zoom magnification setting means are general techniques, a detailed description thereof is omitted, but they are built in the camera.

4 to 6 show how the direction of the camera 1, the focal length, and the zoom magnification of the lower one of the cameras installed as described above and the tool 2 of the turret tool post photographed by the camera are shown. FIG. 4 is a plan view, FIG. 5 is a side view, and FIG. 6 is a perspective view. The reference position O in the Z-axis direction of the workpiece 3 to be processed is the bottom surface of the chuck 5, and the distance of the camera center C from the reference position O in the Z-axis direction is z ₀ . The distance in the X-axis direction from the main axis A of the camera center C is L, and the height in the Y-axis direction is H. Q is the position of the camera center C on the principal axis a. As described above, the turning angle φ around the s-axis is controlled in the camera 1, and the line of sight b of the camera 1 moves on the main axis line a by the turning.

  If the position of the cutting edge of the tool 2 is T and the coordinates of the point T are z and x, the coordinates z and x are the coordinates of the machining point on the workpiece surface in the workpiece coordinate system. Assuming that θ is an angle obtained by projecting the camera turning angle φ about the axis s when the camera's line of sight b is directed to the point T onto the ZX plane,

という関係が成り立つ。また、カメラ中心Ｃから刃先Ｔ迄の距離Ｆは、

This relationship holds. The distance F from the camera center C to the blade edge T is

である。

It is.

  From the above, the angle φ around the turning axis s of the camera base 11 and the distance F from the camera center to the tool cutting edge are expressed as a function of the coordinates z and x of the tool cutting edge T. Therefore, if the position of the tool cutting edge T is known, the direction of the camera 1 and the distance F from the camera 1 to the subject T can be obtained by calculation. Here, z and x are values that can be obtained from the coordinates of the tool post controlled by the NC device, and the focus of the camera 1 can be set if the distance from the camera center C to the processing portion T is known. If the zoom magnification is continuously changed according to the distance F, the tracking shooting area can be maintained at a constant size.

Since the camera 1 is viewing the spindle axis a from a position higher by L in the Y-axis direction, the machining part (tool cutting edge) T to be photographed is only controlled by the turning angle φ around the axis s of the camera 1 described above. The position is shifted by e (see FIG. 5) from the center of the image. If an appropriate zoom magnification is selected, the processing portion T can be kept within the shooting area of the camera 1, but if the processing portion T is to be always placed at the center of the image, the camera 1 is set to Y. Elevating platform 12 that moves in the axial direction is provided, and its elevating position is set to e = xH / L
It is only necessary to control the relationship.

The above is for tracking the processing part T by turning around the axis s of the camera 1 and moving up and down in the Y-axis direction, but instead of turning around the axis s, the movement of the camera 1 in the Z-axis direction, Instead of moving up and down in the Y-axis direction, the camera can be turned up and down around an axis parallel to the main axis a. Further, turning around the axis s of the camera 1 and movement in the Z-axis direction can be used together so that the camera can be moved when the line of sight b of the camera is blocked. In this case, z ₀ in the calculation formula corresponding to the movement of the camera 1 in the Z-axis direction may be changed.

  Further, in the above example, the direction of the optical axis of the camera or the position of the camera is moved. However, as shown in FIG. 7, the direction of the camera having a wide field of view is fixed at a fixed position, and from the image A of the camera. By changing the cutout area B of the image that is cut out and displayed on the display in accordance with the movement of the processing portion T, the processing portion can be tracked. The image cutout area B in this case uses the zoom magnification calculated from the distance F by converting the camera turning angle φ and the elevation position e calculated above into the position of the cutout center on the image plane A of the camera. Can be set by determining the size of the image.

The machining program for the NC lathe is created based on the shape of the workpiece, that is, the coordinate T of the tool edge. A general NC device converts the coordinates (work coordinates) specified in the machining program into a machine coordinate system based on the offset value of the tool being used and the machine origin position of the tool post, and converts the tool rest 4 I have control. Therefore, the coordinates of the tool cutting edge at the start point and end point of a series of machining can be obtained from the NC device, but the coordinates of the cutting edge of a tool that is performing an arc motion by, for example, arc correction during machining are directly obtained from the NC device. I can't do it. However, since the conversion formula for converting the workpiece coordinate system to the machine coordinate system has already been registered in the NC device, if it is converted in the reverse direction, the tool cutting edge can be determined from the command value given to each tool post from the NC device. Can be calculated. Accordingly, the camera can be controlled as described above by using the z and x values of the workpiece coordinates that are inversely calculated from the machine coordinates.

  The lathe of FIG. 1 has two turrets on the lower side. As described above for the respective tool rests, the cameras 1a and 1b can be directed to the tool cutting edges T mounted on the respective tool rests. By sending control data for the same tool rest to the cameras 1a and 1b on both sides, the line of sight b is directed to the cutting edge T of the same tool, and depending on which of the images of the cameras 1a and 1b is selected and displayed on the display, the processing unit You can change the viewing direction. That is, the same processed part can be observed from different directions by operating the switch for switching between the cameras 1a and 1b. For example, when the line of sight of the left camera is blocked by another device, the screen is switched to the image of the right camera. Can continue to observe. In addition, when the tool used for machining is changed, the direction of viewing the machining portion T is automatically switched by automatically switching the changeover switch according to the direction of the cutting edge of the tool 2 (see FIG. 3). Can do.

  Further, which turret is used for the cameras 1a and 1b depending on whether the z and x coordinates for controlling the cameras 1a and 1b are acquired from the control signal for the left tool post 4a or the control signal for the right tool post 4b. It is possible to select whether to point to the tool edge of the tool. Therefore, by switching the coordinate signal to be acquired by operating the changeover switch of the signal to be acquired, it is displayed on the display from the machining part of the tool on the left turret to the machining part of the tool on the right turret and vice versa. The image to be switched can be switched. For example, when workpieces are transferred between two spindles of a two-spindle opposed lathe, when workpieces are being machined on the left spindle, a signal from the left tool post is acquired and workpieces are transferred. If the signal to be acquired is automatically switched when the workpiece is processed, it is possible to continuously observe the machining portion corresponding to the machining sequence of the workpiece.

  In the above example, the turret tool rests 4a and 4b that move only in the Z-axis and X-axis directions have been described for the sake of simplicity. However, when the tool rest moves in the Y-axis direction, the above-described lifting platform 12 is provided to provide the tool rest. The camera 1 may be moved in the Y-axis direction in response to the Y-axis movement of the table 4c. The workpiece coordinates z, x, and y of the machining unit are workpiece coordinate data that is the basis of the command value for controlling the tool post 4, and the conversion formula for converting the data into the machine coordinate system is any motion. Even turrets that perform are registered in the NC unit. Even if the tool is the tool post 4 that also moves in the B-axis direction, the position T of the tool cutting edge can be calculated by inversely converting the machine coordinates at that time into work coordinates. By registering such an arithmetic expression in the operation panel in advance or acquiring the inversely transformed workpiece coordinates from the NC unit, the turret of any structure can be processed by the camera according to the method of the present invention. The part can be tracked.

FIG. 8 is a block diagram showing an example of a machining state display device in a lathe according to the present invention. The machining status display device PC acquires machine coordinate information, conversion data between workpiece coordinates and machine coordinates, alarm information, and the like from the NC device 20 that controls the lathe with the coordinate information acquisition unit 21. The data conversion unit 22 refers to the acquired conversion data and converts the machine coordinates acquired from the NC device 20 into work coordinates (z, x, y coordinates).

  The focus calculation unit 23 calculates the camera turning angle φ from the acquired workpiece coordinates z, x, and y, and the distance F from the camera C to the photographing target (processing unit) T. Further, a camera that displays an image is selected according to a pre-registered selection criterion, depending on the type of tool acquired from the NC apparatus 20 and the feed direction of the tool post. Further, the zoom magnification is calculated so that the shooting area is constant according to the calculated distance F from the camera to the shooting target. The size of the shooting area can be set to about 5 levels by operating the manual input unit 24, and the camera for displaying an image is forcibly selected (changed) by manual operation from the manual input unit 24. ) Is possible.

  The camera operation unit 25 turns the camera base 11, adjusts the focal length of the camera 1 (1a, 1b), and adjusts the zoom magnification for the camera selected in response to the calculation result of the focus calculation unit 23. Accordingly, the camera 1 acquires an image of the predetermined processing unit T and sends the image to the image display processing unit 26. The image display processing unit 26 displays the acquired image on the display 27.

On the other hand, the display data acquisition unit 28 acquires display data including the machining process performed by the lathe from the NC device 20, a schematic diagram of the workpiece in the process, a block of the machining program, and the like, together with the image acquired by the camera 1. This is displayed on the display 27. Whether the operator performs processing appropriately by comparing the process information displayed on the display 27 or the block of the processing program with the image of the processing portion acquired by the camera while performing manual input operation as necessary. You can check whether. Further, when alarm information is issued from the NC device 20, the alarm information is displayed on the display 27, and the machining part of the tool post where the alarm is generated is displayed on the display 27.

  Note that if the NC device 20 is an NC device that controls the machine in the workpiece coordinate system, the coordinate information acquisition unit 21 can directly acquire the workpiece coordinates (z, x, y coordinates of the tool edge) from the NC device. The data conversion unit 22 is not necessary, and the acquired workpiece coordinates are sent directly to the focus calculation unit 23.

1 (1a to 1d) Camera 2 (2a to 2c) Tool 3 Workpiece 4 (4a to 4c) Tool post 11 Camera stand 12 Lifting table a Spindle axis b Camera line of sight C Camera center e Lifting position F From camera center to cutting edge Distance T Machining part s Swivel axis φ Swivel angle

Claims (4)

In a lathe provided with a plurality of tool posts including a camera installed in a processing space surrounded by a partition wall and a door, and display means for displaying an image acquired by the camera on a display of the operation panel,
It is provided with at least two cameras for photographing a tool mounted on a tool post located on both sides in the spindle axis direction from the outside, and each camera controls a tool post of an NC apparatus that controls the machining operation of the lathe. Based on the coordinate information of the tool cutting edge, the direction or the position is controlled so as to track the workpiece machining position by the tool moving in the machining space , and the coordinate information for each camera is obtained from one of the plurality of tool rests. A lathe equipped with a machining state display device, characterized by comprising switching means for switching from coordinate information to the other coordinate information . In a lathe provided with a plurality of tool posts including a camera installed in a processing space surrounded by a partition wall and a door, and display means for displaying an image acquired by the camera on a display of the operation panel,
The lathe is provided with at least two cameras for photographing a tool mounted on a tool post located on both sides in the spindle axis direction from the outside , and an image area cut out from an image of each camera and displayed on the display is the lathe Based on the coordinate information of the tool post or tool edge of the NC device that controls the machining operation of the machine, the coordinate is controlled to track the workpiece machining position by the tool moving in the machining space , and the coordinates for each camera A lathe provided with a processing state display device, comprising switching means for switching information from one coordinate information of the plurality of tool rests to the other coordinate information . Computation means for computing the distance from the camera to the workpiece processing position is provided, and the zoom magnification of the camera or the cutout area of the camera image is controlled so that the shooting area displayed on the display is constant. The lathe according to claim 1 or 2, characterized by the above. The lathe according to claim 1, 2, or 3 , wherein at least one of the plurality of tool rests is a tool rest to which a rotary tool is attached .

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