JP4066178B2 - Machine tool and its abnormality inspection method - Google Patents

Description

The present invention relates to a machine tool that changes a relative position between a tool and a workpiece to process the workpiece, and an abnormality inspection method thereof .

Conventionally, as this type of machine tool, the load applied to the drive unit for moving the machining tool relative to the workpiece is monitored, and when the load exceeds a preset reference value, One that detects that an unexpected collision has occurred is known. A machine tool having a mechanism for absorbing a collision is also disclosed (see, for example, Patent Document 1). An unexpected collision occurs due to, for example, a shift in the work attachment position or a mistake in the type of work.
JP 11-138380 A (Claim 1, paragraphs [0004] and [0005])

  However, in the configuration of the conventional machine tool described above, an unexpected collision cannot be prevented in advance, and the tool may be deformed by the collision.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a machine tool and abnormal test method capable prevent unexpected collisions tool.

In order to achieve the above object, a machine tool according to the invention of claim 1 includes a work jig for fixing a work, a tool rack storing various tools, and a tool detachably mounted and rotationally driven. A main spindle, a tool changer for mounting one of the tools stored in the tool rack on the main spindle, a drive unit for moving the tool mounted on the main spindle and the workpiece fixed to the work jig, and machining And a controller for executing the machining program and controlling the spindle, tool changer, and drive unit, and according to the tool designation command included in the machining program, various tool a predetermined processing tool attached to the spindle from in accordance with a plurality of mobile commands contained in the machining program, by the drive unit The Engineering tool positioning controls the tip of the machining tool are relatively moved with respect to the workpiece, the machine tool performing the machining on the workpiece, the tool rack, the interference detection point for detecting the interference between the object An interference inspection tool that outputs a detection signal when the interference detection point interferes with an object is stored, and an inspection program executed by the controller is stored in the memory, and an inspection program Is set with offset data to offset the interference detection point of the interference inspection tool toward the side away from the workpiece in the rotation axis direction of the spindle with respect to the tip of the processing tool, and the controller executes the inspection program This makes it possible to create a subprogram for inspection by invalidating commands other than movement commands included in the machining program. And processing of the interference detection point of the interference inspection tool according to the inspection tool attachment command means for attaching the interference inspection tool to the spindle with the tool changer, and the offset data and each movement command of the inspection subprogram. It is characterized in that it functions as an inspection tool movement control means for positioning control to a position offset from the work in the rotation axis direction of the main shaft by the offset data from the tip of the tool .

  The invention according to claim 2 is characterized in that, in the machine tool according to claim 1, the interference inspection tool includes a touch sensor that outputs a detection signal when contacting the object.

  The invention of claim 3 is characterized in that in the machine tool according to claim 1 or 2, the machine tool is configured to stop when the interference inspection tool outputs a detection signal.

  In the machine tool according to claim 1 or 2, in the machine tool according to claim 1 or 2, when the interference inspection tool outputs a detection signal, the movement command being executed is interrupted and the next movement command is executed. The interference inspection tool is characterized in that a movement command when a detection signal is output is stored.

6. An abnormality inspection method for a machine tool according to claim 5 , wherein a work jig for fixing a work, a spindle on which a tool is detachably mounted and rotationally driven, and a tool for exchanging a tool mounted on the spindle. A changer, a drive unit for moving the tool mounted on the spindle and the workpiece fixed to the workpiece jig, and a memory that stores the machining program. When the machining program is executed, According to the tool specification command included in the program, a tool changer attaches a predetermined machining tool to the main spindle from various tools, and according to the multiple movement commands included in the machining program, the machining tool is installed in the drive unit. the tip of the machining tool is controlled positioning by relatively moving the workpiece, the machine tool performing the machining on the workpiece abnormal inspection method odor , To disable a command other than the moving commands in the machining program to create a sub-program for inspection, has an interference detection point for detecting the interference between the object and the interference that the interference detection points the object A tool for interference inspection that outputs a detection signal is attached to the spindle, and the interference detection point of the interference inspection tool is away from the workpiece in the direction of the rotation axis of the spindle relative to the interference detection point of the machining tool. Offset data for offsetting is set in advance, and according to the offset data and each movement command of the inspection subprogram, the interference detection point of the interference inspection tool is set to the spindle by the offset data from the tip of the processing tool. Positioning control is performed at a position offset from the workpiece in the direction of the rotation axis, and based on whether the interference inspection tool outputs a detection signal, Characterized in place to detect the abnormalities including erroneous mounting of the workpiece relative to the jig.

[Inventions of Claims 1 and 2]
In the machine tool according to claim 1, when the inspection program is executed, the interference detection point of the interference inspection tool moves to a position offset from the workpiece in the rotation axis direction of the spindle by the offset data from the tip of the processing tool. Positioning is controlled. At this time, if there is a work error such as the workpiece being set off the normal position or a workpiece different from the normal one being set , the interference detection point of the interference inspection tool will interfere with the workpiece. A detection signal is output. As a result, it is possible to inspect whether or not there is a work mistake, and it is possible to prevent an unexpected collision of the machining tool. In addition, the machine tool of the present invention automatically creates an inspection subprogram from a machining program, improving work efficiency and creating an inspection subprogram by invalidating commands other than movement commands included in the machining program. Therefore, the execution time when the inspection subprogram is executed can be shortened.

  Here, the interference inspection tool may be a contact-type tool that includes a touch sensor and outputs a detection signal when the touch sensor comes into contact with the object (the invention of claim 2). A non-contact type that outputs a detection signal when approaching an object for a predetermined distance or more may be used.

[Invention of claim 3]
Since the machine tool according to the third aspect stops when the interference inspection tool outputs the detection signal, it is easy to identify an operation error based on the stop state.

[Invention of claim 4]
In the machine tool of claim 4, when the interference inspection tool outputs a detection signal, the movement command being executed is interrupted, the next movement command is executed, and the interference inspection tool outputs a detection signal. Since the movement commands are stored, interference inspection can be performed on a plurality of movement commands at a time.

[Invention of claim 5 ]
In the abnormality inspection method for a machine tool according to claim 5, an interference inspection tool is mounted on the main shaft instead of the processing tool, and the interference detection point of the interference inspection tool is set to the rotation axis direction of the main shaft with respect to the tip of the processing tool The offset data for offsetting the workpiece away from the workpiece is set, and the inspection subprogram created by invalidating the commands other than the movement command included in the machining program is executed. Then, positioning control is performed so that the interference detection point of the interference inspection tool moves to a position offset from the workpiece in the rotation axis direction of the main shaft by the offset data from the tip of the machining tool. At this time, if there is a work error such as the workpiece being set off the normal position or a workpiece different from the normal one being set , the interference detection point of the interference inspection tool will interfere with the workpiece. A detection signal is output. Accordingly, it is possible to inspect whether there is a work mistake, and it is possible to prevent an unexpected collision of the work processing tool. Further, in the machine tool abnormality inspection method of the present invention, since the inspection subprogram is created by invalidating the commands other than the movement command included in the machining program, the execution time when the inspection subprogram is executed is reduced. Can be shortened.

Hereinafter, an embodiment of the present invention will be described with reference to FIGS.
The NC processing apparatus 10 (corresponding to the “machine tool ” of the present invention) shown in FIG. 1 is provided with a column 12 and a work jig 16 facing each other on the upper surface of a bed 11. Various workpieces W can be fixed to the workpiece jig 16 on the surface facing the column 12. The column 12 is provided with a main shaft 13 that can be driven to rotate about a rotating shaft that faces in the horizontal direction, and various tools 14 are attached to and detached from the tip of the main shaft 13. Further, the column 12 is provided with a Y-axis drive unit 17 (see FIG. 2) for moving the main shaft 13 in the vertical direction (Y-axis direction). Further, the bed 11 includes a Z-axis drive unit 18 (see FIG. 2) that linearly moves the column 12 in a direction (Z-axis direction) parallel to the rotation axis of the main shaft 13, and a work jig 16. An X-axis drive unit 19 (see FIG. 2) that linearly drives in a horizontal direction (X-axis direction) perpendicular to the facing direction is provided.

  As shown in FIG. 2, the X-axis, Y-axis, and Z-axis drive units 17, 18, and 19 include servomotors 17 </ b> A, 18 </ b> A, and 19 </ b> A as drive sources, and servo amplifiers according to control signals from the controller 40. Thus, each servo motor 17A, 18A, 19A is driven. Thereby, the spindle 13 and the workpiece jig 16 are sequentially positioned and controlled, and the tool 14 fixed to the spindle 13 moves relative to the workpiece W fixed to the workpiece jig 16.

  The NC machining apparatus 10 is provided with a tool rack 20 and a tool changer 21 for automatically changing the tool 14. The tool rack 20 is provided with a plurality of tool boxes with box numbers, and an arbitrary tool 14 can be stored in each tool box. Then, the tool changer 21 exchanges the tool 14 accommodated in the tool box having a predetermined box number and the tool 14 mounted on the main shaft 13 in accordance with an instruction from the controller 40.

  Here, an interference inspection tool 30 (see FIG. 2) is provided as one of the various tools 14 housed in the tool rack 20. The interference inspection tool 30 includes a touch sensor 31 at the tip, and outputs a detection signal when the touch sensor 31 comes into contact with an object. The detection signal of the touch sensor 31 is transmitted to the controller 40 wirelessly.

  Various NC programs are stored in the memory 23 provided in the controller 40. An example of command groups constituting the NC program is shown in Table 1 below. In this table, “G00” or “G01” corresponds to the “move command” according to the present invention.

  Further, FIG. 3A shows a part of the machining program P1 as an example of the NC program. According to the command contents in Table 1, in the machining program P1, the tool 14 stored in the tool box of the box number 10 in the tool rack 20 is designated by the command “T10”, and the tool is designated by the command “M6”. 14 and the tool 14 currently mounted on the spindle 13 are automatically exchanged. Specifically, when a processing tool 14 such as an end mill, a milling cutter, or the like is stored in a tool box of box number 10, the processing tool 14 is attached to the main shaft 13.

  Next, the rotational speed of the spindle 13 is set to 5000 [rpm] by the command “S5000”, and the spindle 13 is rotated forward by the command “M3”. Further, by the command “G00X120.3Y163.5Z212.5”, the workpiece W is moved 120.3 [mm] in the X-axis direction, and the tool 14 is moved 163.5 [mm] in the Y-axis direction and 212 in the Z-axis direction. Move 5 mm.

  Next, the tool 14 of the spindle 13 is moved 3 [mm] in the Z-axis direction by a command “G00Z3”. Thereby, the processing tool 14 is pressed against the workpiece W and positioned with respect to the workpiece W. In this state, the command “G01X135.6Y170.2” moves the workpiece W by 135.6 [mm] in the X-axis direction, and moves the tool 14 of the spindle 13 by 170.2 [mm] in the Y-axis direction. . Thereby, planar processing is performed on the workpiece W.

  The controller 40, when executing the movement command “G00” or “G01”, calculates data of passing points obtained by dividing between the current position and the target position specified by the moving command, and Based on the data, movement command values for driving the servo motors 17A, 18A, and 19A of the X-axis, Y-axis, and Z-axis drive units 17, 18, and 19 are created (see FIG. 2). Then, by giving these movement commands to the servo amplifier at a predetermined cycle, the tool 14 and the workpiece W are controlled to move relative to each other at a predetermined movement speed / acceleration / deceleration.

  An inspection program P2 is stored in the memory 23 of the NC machining apparatus 10 as one of NC programs. This inspection program P2 is shown as a flowchart in FIG. The configuration of the inspection program P2 will be described together with the following description of the operation of the NC machining apparatus 10.

  In order to machine a predetermined workpiece by the NC machining apparatus 10 having the above-described configuration, first, the following preparation work is performed. That is, the machining program P1 and the inspection program P2 are loaded into the NC machining apparatus 10. A predetermined workpiece is set (fixed) on the workpiece jig 16. In the tool rack 20, various processing tools 14 required by the processing program P1 are stored in each tool box having a designated box number. The interference inspection tool 30 is accommodated in the tool box having the box number designated by the inspection program P2. Thus, the preparation work is completed.

When the preparatory work is completed, the inspection program P2 is executed. Then, automatic conversion of the machining data is performed as shown in FIG. 4 (S1). Specifically, the machining program P1 is copied to be a part of the inspection program P2, and the auxiliary command “G32” is placed before the movement commands (“G00” and “G01”) in the copied machining program P1. It is inserted, and surrounding the other commands other than the movement command in parentheses "(" and ")". Thereby, the inspection subprogram P3 (see FIG. 3B) as a part of the inspection program P2 is automatically created. Here, the auxiliary command “G32” is set to stop the servo motors 17A, 18A, and 19A on condition that a detection signal is output from the interference inspection tool 30. In addition, commands other than the movement command are not executed (invalidated) by being surrounded by parentheses “(” and “)”. Specifically, for example, tool replacement is not performed, and a coolant supply command is also ignored.

  Next, an offset amount is set according to a request from the controller 40 (S2). Specifically, parameters (for example, a total length, a width, etc.) relating to the structure of the interference inspection tool 30 are set in advance in the inspection program P2. When the offset amount is set to “0”, the tip of the interference inspection tool 30 provided with the touch sensor 31 is positioned and controlled at the same position as the tip of each tool 14 used in the processing program P1. . When the offset amount is “L1”, the position where the tip of the interference inspection tool 30 is offset from the tip of each tool 14 used in the machining program P1 by L1 [mm] in the Z direction and away from the workpiece W. Is positioned. Here, in the machining program P1 of the present embodiment, the movement command “G00Z3” causes the tool 14 to advance 3 [mm] and abut against the workpiece W, so that it interferes with the regular workpiece W. In order to prevent the inspection tool 30 from coming into contact, for example, the offset amount is set to “10”.

  When the above operation is completed, the tool changer 21 is activated, the interference inspection tool 30 is automatically mounted on the spindle 13 (S3), and automatic operation using the inspection subprogram P3 is executed (S4).

  Then, the first line including the movement command in the command group of the inspection subprogram P3 is executed (S5). As a result, at least one of the X-axis, Y-axis, and Z-axis drive units 17, 18, and 19 is driven, and the interference inspection tool 30 moves relative to the workpiece W. At this time, the touch sensor 31 at the tip of the interference inspection tool 30 moves the region away from the workpiece W by, for example, 10 [mm] of the offset amount set in step S2 with respect to the movement path of the tip of the tool 14. Moving. Then, it is checked whether or not the touch sensor 31 has contacted the workpiece W or the workpiece jig 16 based on whether or not a detection signal is output from the touch sensor 31 of the interference inspection tool 30 during the moving operation. (S6).

  Here, when a detection signal is output from the touch sensor 31 (YES in S6), the controller 40 generates an alarm (S8), stops the NC machining apparatus 10 (S9), and ends the inspection program P2. . The operator checks the cause from the state of the stopped NC machining apparatus 10. For example, the work W is of a different type from the normal one, the attachment position / posture of the work jig 16 is different from the normal one, or the tool set in the machining program P1. For example, the total length of 14 is set to be short. When the cause of the touch sensor 31 coming into contact with the workpiece W or the workpiece jig 16 is clarified, the inspection program P2 may be executed again after resetting the normal state.

  On the other hand, when the execution of the first line of the inspection subprogram P3 is completed without the detection signal being output from the touch sensor 31, it is checked whether or not it is a program end (S7). NO), the next line of the next inspection subprogram P3 is executed (S5). The above operation is repeated until the program end is reached (YES in S7).

  As described above, in the NC processing apparatus 10 according to the present embodiment, the interference inspection tool 30 performs the same operation as at least a part of the relative movement operation of the processing tool 14 in a region separated from and adjacent to the regular workpiece W. At this time, if there is a work error such as the workpiece W being set out of the normal position, a detection signal is output from the interference inspection tool 30, and the work mistake can be found. Thereby, the unexpected collision of the processing tool 14 can be prevented in advance.

  Moreover, in the NC processing device 10, when the interference inspection tool 30 outputs a detection signal, the movement command that has been executed is interrupted and stopped, so that it becomes easy to identify an operation error according to the stop state, Damage to the interference inspection tool 30 can be prevented. In addition, since the NC machining apparatus 10 automatically creates a part of the inspection program P2, work efficiency is improved, and the automatically created inspection program P2 invalidates the machining condition setting command for setting the machining conditions. As a result, the execution time can be shortened.

  The interference inspection tool 30 may be a non-contact type that outputs a detection signal when approaching the workpiece W or the workpiece W jig by a predetermined distance or more.

[Other Embodiments]
The present invention is not limited to the above-described embodiment. For example, the embodiments described below are also included in the technical scope of the present invention, and various other than the following can be made without departing from the scope of the invention. It can be changed and implemented.
(1) As a modification of the embodiment, the contents of the auxiliary command inserted before the movement command when the inspection program P2 is executed, for example, that the detection signal is output from the interference inspection tool 30 As a condition, it may be set so that the movement command that has been executed is interrupted, the next movement command is executed, and the movement command when the detection signal is output is stored. With this configuration, interference inspection can be performed for a plurality of movement commands at a time.

  (2) In the above embodiment, the case where the present invention is applied to the NC processing apparatus 10 as a machine tool is exemplified, but the present invention may be applied to a robot as a machine tool. Moreover, you may apply to the inspection apparatus etc. which test | inspect the shape etc. of a workpiece | work other than a machine tool, for example. Moreover, you may apply to the inspection apparatus etc. which test | inspect the shape etc. of a workpiece | work other than a machine tool, for example.

  (3) In the above embodiment, the machining program P1 is converted and a part of the inspection program P2 is automatically created. However, the operator manually assists before the movement command of the machining program P1. A part of the inspection program P2 may be created by inserting a command.

  (4) In the above embodiment, the inspection program P2 is executed by the operator's operation. However, the NC machining apparatus 10 is turned on or the work is replaced with the next work. The inspection program P2 may be automatically executed under the above conditions.

1 is a conceptual diagram of a machine tool according to an embodiment of the present invention. Block diagram showing electrical configuration of machine tool (A) A part of program list of machining program, (B) Part of program list of inspection subprogram Program list of inspection program

Explanation of symbols

10 NC machining apparatus (machine tool)
13 main shaft <br/> 14 tool 30 for interference inspection tool 31 touch sensor W workpiece

Claims (5)

A workpiece jig for fixing the workpiece;
Tool rack that stores various tools,
A spindle on which the tool is detachably mounted and rotationally driven;
A tool changer for mounting any of the tools stored in the tool rack to the main shaft;
A drive unit for relatively moving the tool mounted on the spindle and the workpiece fixed to the workpiece jig;
A memory storing a machining program;
A controller that executes the machining program and controls the spindle, the tool changer, and the drive unit;
In accordance with a tool designation command included in the machining program, a predetermined machining tool is mounted on the spindle from the various tools by the tool changer, and a plurality of movement commands included in the machining program are used. In a machine tool for controlling the position of the tip of the processing tool by moving the processing tool relative to the work in the drive unit , and processing the work,
The tool rack has an interference inspection tool that has an interference detection point for detecting interference with an object and outputs a detection signal when the interference detection point interferes with the object,
The memory stores an inspection program to be executed by the controller, and the inspection program defines the interference detection point of the interference inspection tool with respect to the tip of the machining tool. Offset data for offsetting to the side away from the workpiece in the rotation axis direction is set,
The controller executes the inspection program,
A program creation means for creating a subprogram for inspection by invalidating a command other than the movement command included in the machining program;
An inspection tool attachment command means for attaching the interference inspection tool to the spindle by the tool changer;
According to the offset data and the movement commands of the inspection subprogram, the interference detection point of the interference inspection tool is moved in the direction of the rotation axis of the spindle by the offset data from the tip of the processing tool. A machine tool that functions as inspection tool movement control means for positioning control to a position offset from the workpiece.   The machine tool according to claim 1, wherein the interference inspection tool includes a touch sensor that outputs the detection signal when contacting the object.   The machine tool according to claim 1, wherein the interference inspection tool is configured to stop when a detection signal is output.   When the interference inspection tool outputs a detection signal, the movement command being executed is interrupted, the next movement command is executed, and the movement command when the interference inspection tool outputs a detection signal is stored. The machine tool according to claim 1, wherein the machine tool is configured as described above. A workpiece jig for fixing the workpiece;
A spindle on which a tool is detachably mounted and can be rotated;
A tool changer for exchanging a tool attached to the spindle;
A drive unit for relatively moving the tool mounted on the spindle and the workpiece fixed to the workpiece jig;
A memory storing a machining program,
When the machining program is executed, according to a tool designation command included in the machining program, a predetermined machining tool is mounted on the spindle from the various tools by the tool changer , and the machining program In accordance with a plurality of movement commands included in the machine tool, the drive unit moves the machining tool relative to the workpiece to control the positioning of the tip of the machining tool, and performs an abnormality inspection of the machine tool that performs machining on the workpiece In the method
Create a subprogram for inspection by invalidating commands other than the movement command included in the machining program,
An interference inspection tool that has an interference detection point for detecting interference with an object and outputs a detection signal when the interference detection point interferes with the object is mounted on the spindle, and Setting offset data for offsetting the interference detection point of the interference inspection tool to the side away from the workpiece in the rotation axis direction of the spindle relative to the interference detection point of the processing tool,
According to the offset data and the movement commands of the inspection subprogram, the interference detection point of the interference inspection tool is moved in the direction of the rotation axis of the main shaft by the offset data from the tip of the processing tool. Positioning control is performed at a position offset from the workpiece, and an abnormality including erroneous attachment of the workpiece to the workpiece jig is detected based on whether or not the interference inspection tool outputs the detection signal. Inspection method for machine tools .

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