JP6538345B2 - Work measuring device of machine tool - Google Patents

Description

  The present invention relates to an apparatus for measuring workpiece dimensions in a machine tool.

  The workpiece machined by the machine tool measures the dimensions of the workpiece in order to confirm whether or not the workpiece is machined with the specified dimensions and accuracy. In the past, the machined workpiece was taken out of the machine tool and measured using a micrometer or a three-dimensional measuring instrument, but in the machine of the machine tool where machining of the workpiece was performed to improve the efficiency or automation of the measurement operation. Measurement of workpieces is also increasing. In addition, in the case of test processing, it is also possible to measure a workpiece during processing, and in this case, it is convenient to perform measurement inside the machine.

  Conventionally, a touch probe (detection needle) for detecting a contact with a work is mounted on a tool rest as a means for measuring a work in a machine tool, and the operator manually moves the tool rest to detect the detection end of the touch probe Is brought into contact with the work, and the coordinates of the tool rest are read when the touch probe outputs a contact signal, and the dimensions of the work are calculated based on the tool rest coordinates of the plurality of contact points.

  In this manual measurement, the operator needs to repeat the operation of turning the handle of the manual pulse generator provided on the NC machine tool to bring the detection end of the touch probe into contact with the defined position of the work a plurality of times. It is complicated and time consuming. In addition, there is a risk of causing the touch probe to collide with a part other than the contact point of the workpiece or the chuck while the tool post is moving.

  When a large number of workpieces are to be machined automatically continuously, measurement of the workpieces at predetermined intervals is performed to avoid continuous machining and generation of a large number of defective products while the machining accuracy is lowered due to wear of the tool tip or the like. Need to do. Therefore, a measurement program for automatically performing the above-described manual operation is created, and the program is called at a predetermined timing to perform automatic measurement.

  However, creating a measurement program requires specialized knowledge and takes time. In addition, with a measurement program for measuring a completed work, it is not possible to measure a work in the middle of processing. The workpiece may be machined manually, and it may be desirable to measure the dimensions of the workpiece during machining, so in such a case it is impossible to create a machining program each time.

  According to the present invention, it is possible to reduce work load of the operator when measuring the work manually, prevent an accident such as breakage of the touch probe due to an erroneous operation, and measure the work more easily. As the first issue. Furthermore, this invention makes it a subject to provide the means which can produce the said program easily and in a short time, when it is necessary to produce a measurement program.

  According to the present invention, the camera 2 installed in the machine tool takes a picture of a workpiece w before and after machining or during machining, displays the image p on the display 8 of the operation panel, and wants to measure on the screen (measurement point When the operator designates the measurement position by designating the), the detection end 31 of the touch probe 3 mounted on the tool post is automatically moved to the measurement position, and the detection signal of the touch probe is received during the movement The above problem is solved by acquiring the coordinates of the tool rest 5.

  The workpiece measurement apparatus for a machine tool according to the present invention comprises a tool rest 5 moving on a two-dimensional plane, a display 8 comprising a touch panel, a camera 2 for photographing a workpiece w from a direction orthogonal to the plane, and a workpiece Work image acquisition means 11 for acquiring an image p, display means 12 for displaying the acquired work image on the display 8, and measurement of the touch coordinates of the touch coordinates when the display panel is touched in a state where the work image p is displayed Movement path of the tool rest between measurement points in the path where the measurement point acquiring means 14 and the touch probe 3 mounted on the tool rest 5 of the machine tool do not enter the interference area i set based on the workpiece image p And the tool rest when the detection signal of the touch probe 3 is received while the tool rest 5 travels the route acquired by the path acquisition means 15 Includes a coordinate acquisition unit 16 for acquiring targets, and a workpiece size acquisition means 17 that acquires the size of the workpiece w from a plurality of tool rests coordinates obtained.

  The workpiece measuring apparatus according to the present invention provided with the above-described means captures an image of the inside of the machine with the camera 2 when measurement of workpiece dimensions is instructed from the control panel of the controller 1, acquires a workpiece image p from the acquired image, w and the necessary interference regions i, j of the chuck 4 and other mechanical members are calculated, the boundaries between the workpiece image p and the interference regions i, j are displayed on the display 8, and a signal for measuring points is awaited. Each time a measurement point is specified, the coordinates of the measurement point are stored, and when the designation end signal is received, a path for sequentially moving the detection end 31 of the touch probe to a plurality of measurement points is acquired and the path is moved. When the detection signal of the touch probe is received, the coordinates of the tool rest 5 are read, and the tool rest is moved to the next measurement point. Then, after the movement between the measurement points is completed, the dimensions between the measurement points are calculated from the acquired plurality of tool post coordinates and displayed on the display.

  There are innumerable movement paths between measurement points, but it is possible to calculate a path that performs linear movement and direction conversion in the reference movement direction of the tool rest (Z-X axis direction for a lathe) with a small number of times or Pre-register a plurality of path patterns (for example, L-shaped or U-shaped path patterns), display the path patterns on the display screen, and allow the operator to specify measurement points and select path patterns. It is possible to set an appropriate movement route.

  In this invention, not only the measurement of the material work and the complete work but also the measurement of the work shape at an arbitrary time during processing can be performed immediately when it is necessary to display the work image photographed by the camera Since the measurement point is designated on the display screen, the operator can designate the measurement point easily and freely, and it is possible to easily measure the necessary point when necessary.

  Also, it is possible to perform automatic measurement with the touch probe just by specifying the position to be measured, and to shorten the measurement time. Furthermore, it is possible to output a measurement program to be used at the time of continuous automatic machining of a workpiece, and can also be used as a tool for creating a measurement program semi-automatically.

Block diagram showing the main part of the lathe on which the measuring device of the present invention is mounted A diagram showing an example of an image displayed on a display Explanatory drawing of the movement path of the detection end

  Hereinafter, embodiments of the present invention will be described with reference to the attached drawings. FIG. 1 is a schematic plan view of a lathe on which the measuring device of the present invention is mounted, in which 4 is a work chuck attached to the end of a spindle (not shown), w is a work gripped by the work chuck 4 3 is a touch probe. The touch probe 3 is mounted via a holder 7 at one position of a tool mounting station of the turret 6 mounted on the tool rest 5. The exact positional relationship between the detection end 31 of the touch probe and the reference coordinates 51 of the tool rest is registered in the CNC device 1 controlling the lathe.

  The camera 2 is installed on the upper side of the spindle axis a, which is the rotation center of the chuck 4, that is, on the front side of the drawing sheet with its optical axis oriented in the direction orthogonal to the movement plane (Z-X plane) of the tool rest 5. There is.

  The CNC apparatus 1 includes a work image acquisition unit 11 including an image memory 21, a display unit 12, an interference area setting unit 13, a measurement point acquisition unit 14, a path acquisition unit 15, a coordinate acquisition unit 16, a workpiece dimension acquisition unit 17, and The route output means 18 or / and the route storage means 19 are registered.

  In the image memory 21, an image of the camera 2 photographed in a state where the work w is not attached is recorded. The work image acquisition unit 11 photographs the work w with the camera 2 and acquires the image according to the instruction of the operator from the operation panel, and the difference image between the acquired image and the image stored in the image memory 21 The image p of the work is extracted, and the extracted data is sent to the display means 12. The display means 12 displays the extracted workpiece image p on the display 8 of the CNC device 1.

  The interference area setting unit 13 determines the interference area i of the workpiece w on the ZX plane on which the detection end 31 of the touch probe moves by image analysis, and the area data of the interference area j of the chuck 4 previously obtained. It sends to the display means 12 with the area data. The display means 12 displays the boundary of the interference area i, j on the display 8 together with the work image p.

  In FIG. 2, a workpiece image p on a detection surface obtained by image analysis from an image acquired by the camera 2 is displayed. The interference area setting means 13 extends the boundary of the interference area i, j to a position where the boundary of the work image p thus obtained is extended by the safe distance e necessary to avoid the collision between the touch probe 3 and the work w. Set

  As shown in FIG. 2, the interference area is set not only for the workpiece w but also for the chuck 4 as needed. The shape and dimensions of the chuck 4 are known, and in a machine tool provided with interference check means for avoiding interference (collision) between the tool and the chuck, interference between the touch probe 3 and the chuck 4 can be prevented by the interference check means. . In a machine tool not provided with the interference check means, the interference area j for the chuck 4 can be set by the same image analysis means for the workpiece w from the image of the chuck 4 acquired by the camera 2.

  When the pressing signal is output from the display 8 including the touch panel, the measuring point acquiring unit 14 acquires the coordinates of the pressing point, and stores the point on the boundary of the workpiece image p closest to the pressing point as the measuring point. . When one measurement point m1 is acquired, the measurement point acquisition unit 14 acquires a point m2 on a boundary located at a symmetrical position sandwiching the spindle axis a as a measurement point forming a pair with the acquired measurement point m1. Good. For example, when measurement of a diameter dimension is instructed by the operator, the pair of measurement points m2 may be acquired.

  After acquiring the measurement points, when the confirmation signal from the operation panel is received, the path acquisition means 15 sets the movement path of the tool rest 5 for bringing the detection end 31 of the touch probe into contact with all acquired measurement points. Do. Normally, the tool post of the machine tool is equipped with a linear feeding device in the direction of two orthogonal axes (in the case of a lathe, in the Z-axis direction and the X-axis direction). Linear paths Lz and Lx in the axial direction are set close to the interference region i, and a direction orthogonal to the boundary of the workpiece image at each measurement point (axial direction close to the orthogonal direction if the boundary is oblique) By selecting the path with the least crossing point (refractive point) among the paths sequentially traversing the approach path La and the straight paths Lz and Lx crossing this, it is possible to acquire an appropriate moving path .

  The movement order of a plurality of measurement points is divided into two groups depending on whether it is above or below the spindle axis a, and on each side is taken as a path to sequentially measure adjacent measurement points from one measurement point at one end. Is good.

  Moreover, in the measurement of a workpiece having a complicated shape, several kinds of path patterns, ie, U-shaped or L-shaped path patterns r1, r2. Are displayed on the display 8 to be selected by the operator, and position setting means 23 for calculating the positions of straight lines and inflection points of the specified path pattern may be provided. The pattern designation unit 22 causes the operator to select which path pattern to use by a touch operation each time the movement to the measurement point is started.

  When a certain path pattern is designated, the position setting means 23 moves the coordinates of the straight line or inflection point included in the pattern when moving the detection end 31 of the touch probe along the path of the pattern to the path. The movement is set so that the detection end 31 of the touch probe does not enter into the interference area during movement along.

  Thus, when the movement trajectory of measurement conversion is set, the coordinate acquisition means 16 starts the movement of the tool rest and moves the movement speed of the tool rest at high speed when the detection end approaches the predetermined distance. Switch to low speed movement, stop the tool rest when the detection signal is output from the touch probe 3 during this low speed movement, and use the tool rest coordinates when the detection signal is output as the coordinates corresponding to the measurement point Store and move the tool rest along the movement path to the next measurement point. After acquiring the coordinates of all the measurement points, the coordinate acquisition means 16 returns the tool rest 5 to the origin position at the start of measurement.

  With the above operation, it is possible to acquire the same coordinates as when the operator manually moves the toolgroup to acquire the coordinates of the measurement point, so the workpiece dimension acquisition means 17 uses the coordinates of these measurement points to calculate the diameter of the workpiece. Calculates dimensions such as length dimensions and displays them on the display screen.

  If the above-mentioned work measurement procedure is executed for the completed work, the operation at that time is the operation to be executed by the measurement program at the time of work dimension measurement for checking the work accuracy of the work during continuous automatic processing as it is. By providing the path output means 18 for outputting the operation data or the path storage means 19 for storing in the CNC device, it becomes possible to easily create a measurement program for the work.

  That is, since the machining accuracy of the workpiece can be measured by calling the stored operation timely during continuous automatic machining of the workpiece, it is possible to determine the setting of the interval for calling those operations and whether the measured machining accuracy is good or not. Automatic continuous machining can be realized while checking the machining accuracy of the workpiece only by adding the discrimination procedure.

Reference Signs List 1 controller 2 camera 3 touch probe 4 chuck 5 tool rest 8 display 11 workpiece image acquisition unit 12 display unit 14 measurement point acquisition unit 15 path acquisition unit 16 coordinate acquisition unit 17 workpiece dimension acquisition unit 31 detection end p workpiece image w workpiece i, j interference area

Claims (4)

A tool rest moving on a two-dimensional plane, a display comprising a touch panel, a camera for photographing a workpiece from a direction orthogonal to the plane, a workpiece image acquiring means for acquiring a workpiece image from an image of the camera, and the acquired workpiece image Display means for displaying on the display;
Measurement point acquisition means for setting the touch coordinates as measurement points of the work when the display panel is touched in a state where the work image is displayed;
A path acquisition means for automatically acquiring a movement path of the tool rest between the measurement points in a path where the touch probe mounted on the tool rest of the machine tool does not enter the interference area set based on the workpiece image;
Coordinate acquisition means for acquiring the cutter post coordinates when the detection signal of the touch probe is received while the tool rest travels the path acquired by the path acquisition means;
Workpiece dimension acquisition means for acquiring the dimensions of the workpiece from the acquired plurality of tool post coordinates
Work measuring device for machine tools.   The path acquisition means sets a plurality of path patterns registered in advance, pattern designating means for causing the operator to select one path from the path patterns, and positions of straight lines or inflection points of the specified path pattern. The workpiece measurement device according to claim 1, further comprising: a position setting unit.   The workpiece measurement device according to claim 1, further comprising path output means for outputting path data acquired by the path acquisition means.   An image of the workpiece from an image memory storing the image of the camera when the workpiece image acquiring means is not wearing the workpiece, and a difference image between the camera image when the workpiece is mounted and the image stored in the image memory The workpiece measurement device according to claim 1, 2 or 3, wherein

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