JP2015009345A - Setting device and setting method for tool correction value of machine tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide technical means which enables a rapid setting of tool correction values (tool offset values) of a plurality of tools mounted on a cutter holder of a machine tool in regard to means for setting the tool correction values mounted on a cutter holder of a machine tool.SOLUTION: When an operation procedure of a cutter holder for automatically setting a tool correction value is registered in a controller for every tool set consisting of the combination of the type of a tool holder to be mounted on the cutter holder and the type of a tool to have a tool set designated, a corresponding operation procedure is called with an initial correction value serving as the argument. When a detection signal of a tool blade tip is received during execution of the operation procedure, a tool correction value about the axis of a direction of movement is calculated from the coordinates of the cutter holder in the direction of movement at that time and set in the controller.

Description

  The present invention relates to an apparatus and a method for setting a correction value (tool offset value) of a tool mounted on a tool post of a machine tool in a controller.

  The machining shape of a workpiece (processing object) by a machine tool is determined by how the cutting edge of the tool is moved relative to the workpiece. On the other hand, what is controlled by the controller of the machine tool is the relative positional relationship between the spindle or table on which the workpiece is fixed and the tool post on which the tool is mounted.

  Various tools corresponding to the type of processing are mounted on the tool post. Since the length and direction of protrusion from the tool rest differ depending on the tool, the positional relationship from the reference position of the tool rest (the position recognized or controlled by the controller) to the tool cutting edge must be registered in the controller in advance. The desired processing cannot be performed. Therefore, when the tool is attached to the tool post, the position of the tool edge (tool correction value) with respect to the reference position of the tool post is set in the controller.

  The tool correction value is usually set by installing a tool setter equipped with a detection switch such as a proximity switch or touch sensor that detects the tool edge at a predetermined position, and after mounting the tool on the tool post, This is done by moving and detecting the tool edge with a detection sensor and obtaining a tool correction value based on the position of the tool post (position recognized by the controller) when the detection signal is received.

  Conventionally, an operator manually performs an operation of detecting a tool edge when setting a tool correction value by a tool setter and an operation of setting (registering) a tool correction value in a controller. For example, in the case of a turret lathe, the tool station to which the tool whose tool correction value is to be set is determined, the tool post is manually moved to the position where the tool tip is detected by the detection sensor, and detected. After confirming that the tool edge detection signal is output from the sensor and the tool correction value is set in the controller, the tool rest is moved away from the tool setter, and the turret is rotated to determine the next tool. The tool compensation value was set by repeating the operation.

  In view of the fact that it takes time to set the tool correction value by such manual operation, Patent Document 1 proposes a means for automatically measuring and setting the length of the drill mounted on the chuck of the tool spindle for the drilling machine. Has been.

JP 7-276122 A

  In a machine tool that performs processing using a plurality of tools such as a turret lathe, a plurality of tools such as 8 or 12 are mounted on one tool post (turret), and the direction of the blade edge is mounted on one tool station. Since there are cases where two tools having different values are mounted, there is a problem that it takes a lot of labor and time to manually set the tool correction value in the controller for these tools.

  Moreover, in a compound lathe equipped with a turret lathe and a tool changer, there are many types of tools used for machining, and not only the length of the tool protruding from the tool rest but also the position and direction of the cutting edge are different. Furthermore, since these tools are mounted on the turret via the tool holder, even when the same tool is used, the tool correction value changes depending on the shape and dimensions of the tool holder to be used.

  Therefore, the direction in which the cutting edge approaches the tool setter differs depending on the type of tool mounted on the tool post, and more tools have a tool correction value if they do not detect the cutting edge by approaching the tool setter from multiple directions. Cannot be set.

  The present invention solves the above-mentioned problems in a machine tool such as a turret lathe and provides technical means capable of quickly setting tool correction values for a plurality of tools mounted on a tool post. Is an issue.

  In this invention, the operation of the tool post when the tool correction value is automatically set for each tool set consisting of combinations of the types 4a to 4d of the tool holder 4 mounted on the tool post 3 and the types 5a to 5g of the tool 5. When the procedure is registered in the controller 1 and a tool set mounted on the tool post 3 is designated, a tool correction value for the tool set is automatically set.

  The initial correction value used in the tool set and operation procedure is input by an operator or stored in the controller 1 in advance. When a tool set and an initial correction value are specified, the corresponding operation procedure is called with the initial correction value as an argument. The operation procedure registered for each tool set includes moving the tool post to the detection start point at a high speed, approaching the detection sensor 60 at a low speed from the direction corresponding to the tool set, and high-speed retreat after receiving the detection signal. When the next movement axis is designated, the conversion movement in the direction of the next movement axis is repeated.

  When a detection signal is received from the tool edge detection sensor 60 during this repeated operation, the tool correction value for the axis in the movement direction is calculated from the coordinates in the movement direction of the tool post 3 at that time, and the controller 1 automatically Set.

  The tool correction value setting apparatus for carrying out the method of the present invention includes a table 11 in which an operation procedure is registered as an operation program or call information of the program for each combination of holder type and tool type. In this table, display data of the tool set on the display 10 can be registered.

  The tool correction value setting device of the present invention further includes a tool set display means 12 and a selection signal acquisition means 13. The tool set display means 12 displays all necessary tool sets on the display 10 of the controller, preferably as an image, based on the display data of the tool set registered in the table or other storage area. The operator confirms the mounting state of the tool and selects a corresponding tool set. The selection signal acquisition unit 13 acquires this selection signal. When the number of tool sets registered in the table 11 is large, for example, the tool set is displayed separately in a tool holder list and a tool list, and when one holder is selected from the holder list, A tool set is acquired by displaying a list of tools that can be mounted on the holder and selecting a tool.

  The correction value setting apparatus according to the present invention further includes an initial correction value input means or registration means 14, a correction value calculation means 15, and a correction value setting means 16. After the tool set is selected, the operation procedure registered in the table 11 corresponding to the tool set is called with the initial correction value as an argument. When the initial correction value is not registered in advance, the operation procedure waits for the input of the initial correction value. The operator measures, for example, Z and X from the reference position O of the tool post to the tool cutting edge and, if necessary, the dimension in the Y-axis direction, and inputs them to the controller 1.

  When necessary information is acquired by the above procedure, the called operation procedure moves the tool edge to the detection start point s by rapid traverse based on the initial correction value. Since the initial correction value includes an error, the detection start points s and t are set at positions that take this error into consideration. Next, the operation procedure includes low-speed movement of the tool post 3 in each axial direction, high-speed retraction of the tool post 3 after the detection sensor 60 detects the tool cutting edge, and movement of the next detection start point t after converting the axial direction. Are repeated in the registered order.

  When the correction value calculation means 15 receives the detection signal during the low-speed movement of the tool post 3 according to the operation procedure, the correction value calculation means 15 acquires the coordinate in the moving direction of the tool post 3 and calculates the tool correction value in the axial direction, thereby correcting The value setting means 16 registers the calculated correction value in the corresponding storage area.

  When the measurement operations for all the necessary axes are completed, the operation procedure moves the tool post to the indexing position at high speed along the retraction path, indexes the next tool at the position, and An operation is performed to set a correction value in the correction value storage area corresponding to the next tool.

  The tool correction value setting operation as described above is performed when a new tool 5 is mounted on the tool post 3, but a predetermined amount of machining is performed on the finishing tool in order to avoid a reduction in machining accuracy due to wear of the cutting edge. The tool correction value may be updated each time it is performed. In such a case, for the target tool, the tool correction value for correcting the wear of the blade edge is set by automatically performing the above operation every time a predetermined predetermined machining time elapses. Can do. In this case, the above operation may be performed using the currently registered tool correction value as the initial correction value.

  If you enter or register the type of tool, the type of holder to be used, and the initial correction value to be used for a plurality of tools mounted on the tool post, the operation to bring the tool edge close to the edge detection sensor for those tools, The contact operation to the edge detection sensor corresponding to each tool, and the setting or updating of the tool correction value in the required axial direction (X axis and / or Z axis) for each tool is automatically performed while converting the tool station. Therefore, it is possible to easily and quickly set a tool correction value for a machine tool in which a plurality of tools are used like a turret lathe, and it is possible to prevent an operator's operation error.

  It is also possible to automatically update correction values necessary for automatically correcting machining errors due to cutting edge wear and thermal deformation of machine tools during the continuous machining of workpieces.

Schematic showing the main part of the turret lathe Explanatory drawing showing tool set type and cutting edge detection operation Continuation of Figure 2 Explanatory drawing showing a table Flow chart showing an example of blade edge detection operation Flow chart showing correction value setting procedure Figure showing the holder selection screen Figure showing the tool selection screen

  Next, an embodiment in which the present invention is applied to a turret lathe will be described with reference to the drawings. In FIG. 1 which shows the principal part of a turret lathe, 1 is an NC controller, 2 is a work chuck mounted at the tip of a spindle supported by a spindle stock 21, 3 is a tool post, and 5 (5a to 5g) are tools. A tool 6 attached to the turret 30 of the tool post 3 via the holder 4 (4a to 4d) is a tool setter. The tool post 3 provided with the turret 30 is mounted on a Z feed base 31 that moves in the Z-axis direction (spindle axis direction) so as to be movable in the X-axis direction (tool cutting feed direction), and is controlled by the controller 1. The movement positions on the Z-X plane are controlled by feed motors (servo motors) 32 and 33 in the Z-axis direction and the X-axis direction.

  The controller 1 having the display 10 is a table 11 in which display data and operation procedures are registered for each tool set including combinations of types 5a to 5g of the tool 5 and types 4a to 4d of the tool holder 4 used for the tool 5. A tool set display means 12, a selection signal acquisition means 13, an initial correction value input or registration means 14, a correction value calculation means 15, and a correction value setting means 16. The controller 1 further includes storage means 17 for temporarily storing the acquired tool set selection signal and initial correction value, and operation procedure continuous execution means 18.

  The tool setter 6 is attached to the tip of an arm 62 that moves forward and backward with a cylinder 61, and is normally retracted from a region where a workpiece is processed. The tool setter 6 includes detection sensors 60 on both sides in the Z-axis direction and the X-axis direction. The setting of the tool correction value is performed by bringing the cutting edge of the tool 5 attached to the turret 30 into contact with the sensor 60 of the tool setter and reading the coordinates in the Z and X axis directions of the tool post 3 at the time of contact. Various tools are mounted on the turret 30, and the operation when the blade edge is brought into contact with the detection sensor 60 differs depending on the type of the tool.

  2A and 2B exemplify an example of a tool set mounted on the turret 30 and an operation when detecting the cutting edge of each tool. The reference position O of the tool post 3 is set at the center of each tool mounting station on the outer periphery of the turret 30.

  The tool 5a in FIG. 2 (a) is a thread cutting tool and is attached to the turret 30 via a straight holder 4a. The position of the cutting edge in the Z-axis direction coincides with the reference position O of the tool post. With this type of tool, the correction value in the Z-axis direction is set to 0, and only the correction value Δx in the X-axis direction is detected. The operation of the tool at this time is to move the reference position O of the tool rest on the Z axis line of the tool setter 6 and move the tool blade edge to the detection start point s set using the initial correction value in the X axis direction. This is an operation (operation A) in which the tool rest 3 is approached at a low speed in the X-axis direction toward the tool setter 6 and the tool rest 3 is retracted at a high speed in the X-axis direction when a cutting edge is detected.

  A tool 5b shown in FIG. 5B is an example of a drill for making a hole in the Z-axis direction in a workpiece, and is attached to the turret 30 via an angle-shaped rotary tool holder 4d. In this type of tool, the correction value Δx in the X-axis direction is a constant value determined by the shape of the angle holder 4b, so that the tool center is moved on the main axis line a (on the X-axis line of the tool setter 6). The low-speed approach in the Z-axis direction to the tool setter 6 and the high-speed retraction operation (operation B) in the same direction after the cutting edge is detected.

  A tool 5c shown in FIG. 5C is a cutting tool for machining the right side surface of the workpiece, and is attached to the turret 30 via the straight holder 4a. In this type of tool, after moving the cutting edge of the tool to the detection start point s on the spindle axis line using the initial correction value, the low-speed approach to the tool setter 6 in the Z-axis direction and the cutting edge are detected. The movement to the detection start point t in the X-axis direction set using the initial correction value, the low-speed approach in the X-axis direction, and the high-speed retraction after the blade edge is detected (operation C) Correction values Δz and Δx in the respective X-axis directions are detected.

  A tool 5d shown in FIG. 4D is a cutting tool for turning the left side surface of the workpiece, and is attached to the turret 30 via a straight holder 4a. In this type of tool, the tool edge is moved to the detection start point s on the X-axis line of the tool setter using the initial correction value, and then the tool edge is detected in the X-axis direction and the blade edge is detected. Later, the movement to the detection start point t in the Z-axis direction set using the initial correction value, the low-speed approach in the Z-axis direction, and the high-speed retreat after the blade edge is detected (operation D), Correction values Δz and Δx in the directions of the Z axis and the X axis are detected.

  The tool 5e shown in FIG. 3 (e) is a milling cutter and is attached to the turret 30 via a straight rotary tool holder 4c. This type of tool detects the correction values Δz and Δx by the operation C. A tool 5f shown in FIG. 5F is a boring tool and is attached to the turret 30 via an angle holder 4b. This type of tool detects the correction values Δz and Δx by the operation C. A tool 5g in FIG. 5G is a boring tool for machining the right side surface on the inner diameter side of the workpiece, and is attached to the turret 30 via the angle holder 4b. This type of tool detects the correction values Δz and Δx by the operation D.

  There are various types of tools 5 to be mounted on the turret 30 as described above, and there are also various types of holders 4 used when mounting these tools on the turret. The operation of the tool cutting edge when setting the correction value according to the combination (tool set), and thus the operation of the tool post 3 is also different.

  Therefore, as shown in FIG. 4, the types a to g of the tool 5 and the types a to d of the tool holder 4 used for the tool are registered in the table 11 of the controller 1 together with their display figures. Register the operation procedure when setting the correction value for each combination of tool and holder (tool set). The operation procedure is a program for performing the operations A to D shown in FIGS. 2 and 3. For example, the flowchart of the program for realizing the operation C is as shown in FIG.

  That is, an initial correction value is input or a correction value obtained by adding a margin (margin dimension) to the initial correction value acquired by the registration means 14 is temporarily set, and the tool tip is detected using the correction value in the Z-axis direction. To move fast. Next, when approaching at a low speed toward the tool setter 6 in the Z-axis direction and a detection signal is output from the detection sensor 60 of the tool setter, the Z-axis coordinate of the tool post 3 at that time is acquired and retracted in the Z-axis direction. Then, it moves to the detection start point in the X-axis direction by the axial direction conversion operation. Then, when approaching at a low speed toward the tool setter 6 in the X-axis direction, when the blade edge detection signal is output from the detection sensor 60, the X-axis coordinate of the tool post 3 is acquired and retracted in the X-axis direction. Return to the index rotation position for indexing the tool at high speed.

  When a blade edge detection signal is output from the detection sensor 60 during the execution of such an operation procedure, the correction value calculation means 15 calculates the current tool post coordinates from the current tool post coordinates (coordinates of the reference position O). If the movement direction is the Z-axis direction, a correction value Δz in the Z-axis direction is calculated, and if the movement direction of the tool rest is the X-axis direction, a correction value Δx in the X-axis direction is calculated. Then, the correction value setting means 16 sets the calculated correction values in the Z-axis direction and the X-axis direction as the tool correction values of the currently calculated tool station.

  Next, the tool correction value setting operation will be described with reference to FIG. When the control is switched to the correction mode when the operator's manual operation or the correction value update timing set in the controller 1 is reached and the control is switched to the correction mode, the controller 1 expands the cylinder 61 and moves the tool setter 6 to the predetermined axis a Advance to position. This position is a fixed position that is mechanically set by the support structure of the arm 62.

  In this state, as shown in FIG. 7, the controller displays an image of a list of holders registered in the table 11 on the display 10 of the controller, and shows the tool holder of the tool currently calculated by the operator, for example, When selected by touching the image displayed on the display 10, the controller 1 then displays a list of tools using the selected holder on the display 10 of the controller as shown in FIG. (Steps 41 to 43 in FIG. 6). When the operator selects the currently determined tool, the operation procedure to be called is determined, and the operation procedure is called (step 45).

  If the initial correction value that is an argument when executing the operation procedure is not registered, the input screen is displayed on the display 10 and the input of the operator is waited (step 47). When the operator inputs the initial correction value and presses the confirmation button, the called operation procedure is executed using the initial correction value as an argument (step 49).

  When a detection signal is output from the detection sensor 60 of the tool setter during the operation procedure, the correction value for the currently calculated tool station is stored in a predetermined storage by the correction value calculation means 15 and the correction value setting means 16. Set to area. Next, if there is a tool for which a new correction value is set or updated, the tool station to which the tool is mounted is determined (step 51), and the tool correction value for the station newly determined by the same operation is determined. Otherwise, the correction value setting operation is terminated, and the correction value setting mode is terminated manually or automatically by the operator.

  When the tool correction value is automatically updated during continuous machining of the workpiece in order to prevent an increase in machining error due to wear of the cutting edge of the finishing tool, etc., the designated station number and There is provided a timing setting unit 19 for registering the timing for updating the correction value of the tool mounted on the station of the number (such as the number of workpieces to be processed and the cumulative usage time of the tool for updating the correction value). When the set timing is reached, the correction value is updated by the same method as described above. In the case of updating the correction value, since the controller recognizes the tool to be updated and the holder used therefor, steps 41 to 48 in the procedure of FIG. 6 are not necessary and are actually set. The steps 49 to 51 in FIG. 6 may be executed using the correction value as the initial correction value.

DESCRIPTION OF SYMBOLS 1 Controller 3 Tool post 4 (4a-4d) Tool holder 5 (5a-5g) Tool 10 Display 11 Table 12 Tool set display means 13 Selection signal acquisition means 14 Initial correction value input means or registration means 15 Correction value calculation means 16 Correction value setting means 60 Detection sensor O Reference position of tool post s Detection start point t Detection start point

Claims (6)

A table in which the operation procedure of the tool post is registered for each tool set consisting of a combination of a tool holder type and a tool type mounted on the turret;
Tool set display means for displaying a plurality of tool sets;
Selection signal acquisition means for acquiring a tool set selection signal;
Means for inputting or registering an initial correction value to be given as an argument to the program when executing the operation procedure;
Correction value calculating means for calculating a tool correction value for the axis in the movement direction from the coordinates in the movement direction of the tool post at the time of receiving the detection signal from the tool blade edge detection sensor;
Correction value setting means for registering the correction value calculated by the correction value calculation means in the tool correction value storage area corresponding to the calculated tool station number,
The operation procedure uses the initial correction value to move the tool post to the detection start position at high speed, specify low speed approach to the detection sensor, high speed retreat after receiving the detection signal, and the next movement axis. If it is, after repeating the conversion movement in the next movement axis direction, return the tool post to the index position,
Tool compensation value setting device.   Storage means for temporarily storing the tool set selection signals and initial correction values for a plurality of tool stations of the turret, and a continuous execution means for the operation procedure, the continuous execution means for the plurality of designated stations. The tool set selection signal and the initial correction value are stored, and then the designated plurality of stations are sequentially calculated to operate the operation procedure, the correction value calculation means, and the correction value setting means. Tool compensation value setting device.   The tool correction value setting device according to claim 1 or 2, wherein the tool set display means displays the tool set as an image on a display of the controller.   4. The tool correction value setting device according to claim 1, wherein the tool set display means displays the tool set divided into a holder list and a tool list.   Register a table in which the operation procedure of the tool post is registered for each tool set consisting of a combination of the tool holder type and tool type to be mounted on the turret. All registered tool sets are displayed on the controller's display to obtain initial compensation values for the tools for which selection signals and compensation values are set, and the operation procedure for the tool set specified by the selection signal is performed. When the initial correction value is called as an argument, the tool post is moved to the detection start position at high speed, low speed approach to the detection sensor, high speed retreat after receiving the detection signal, and the next movement axis is specified In this case, the conversion movement in the next movement axis direction is repeated, and the axis in the movement direction is determined from the coordinates in the movement direction of the tool rest when a detection signal is received from the tool edge detection sensor during this repeated operation. Calculates a tool offset value that is stored in the storage area of the corresponding tool compensation values indexed is to have a tool station when, the method of setting the tool compensation value.   A table in which the operation procedure of the tool post is registered for each tool set composed of a combination of the tool holder type and the tool type to be mounted on the turret, and the station registered in the controller in advance is mounted on that station. The tool set is stored, and at every predetermined timing, the operation procedure for the stored tool set is called with the tool correction value set for the station as an argument, and the tool post is moved to the detection start position at a high speed. During this repeated operation, the low-speed approach to the detection sensor, the high-speed retraction after receiving the detection signal, and the conversion movement in the direction of the next movement axis when the next movement axis is specified are repeated. The tool correction value for the axis in the direction of movement is calculated from the coordinates in the direction of movement of the tool rest when the detection signal is received from the tool edge detection sensor. In the storage area of the tool correction value, set the tool compensation value method corresponding to indexed is to have a tool station at.

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