JP7184588B2 - Numerical controller - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a numerical controller, and more particularly to a numerical controller that automatically determines where to reflect work measurement results.

An industrial machine such as a machine tool (hereinafter referred to as a machine) controlled by a numerical controller executes a work measurement program (hereinafter referred to as a measurement program) within the machine after machining a workpiece (see FIG. 1(a)). ) is executed to measure the workpiece shape after machining with a probe or the like (see FIG. 1(b)), and the measurement result is reflected in the tool offset value, that is, the tool offset value may be updated based on the measurement result. (See FIG. 1(c)). As a result, the tool offset value is kept to reflect the latest state of the tool, and machining accuracy can be maintained. For example, Patent Literature 1 discloses a technique of measuring the shape of a workpiece after machining by an NC machine and correcting the tool diameter and tool length based on the measurement results.

JP-A-2000-317775

However, the measurement program does not have means for recognizing what tool was used during machining at the measurement target (measurement position). That is, in the initial state, the location of the tool offset (tool offset number and tool offset type (length or radius)) to which the measurement result should be reflected is unknown. For this reason, conventionally, the operator manually sets the reflection destination (tool offset number and type) in advance, and the measurement program updates the tool offset value according to this setting. Such work was a burden on the operator.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a numerical controller that automatically determines where to reflect workpiece measurement results.

A numerical control device according to a positional embodiment of the present invention is a numerical control device that reflects a measurement result of a workpiece after machining to a tool offset value of a tool, executes a machining simulation, and controls the contact between the tool and the workpiece. a machining simulation unit that associates the contact point, the tool offset type at the time of contact, and the tool offset number at the time of contact; a machining tool specifying unit that determines the tool offset type and the tool offset number associated with the contact point between the tool and the workpiece in the above as a reflection destination of the measurement result; and a reflection unit that reflects the measurement result on the reflection destination. and.
In the numerical control device according to the position embodiment of the present invention, the machining simulation unit associates a contact point between the tool and the workpiece with the surface of the tool at the time of contact, and the machining tool identification unit: selecting one of the tool offset types based on the surface of the tool associated with the contact point between the tool and the workpiece in the machining simulation corresponding to the position at which the measurement probe and the workpiece after machining are in contact; A tool offset number associated with the contact point is selected, and the tool offset type and the tool offset number are determined as the reflection destination of the measurement result.
In the numerical control apparatus according to the positional embodiment of the present invention, when the bottom surface of the tool is in contact with the work, the machining tool specifying unit uses the tool length type of the tool offset number as a reflection destination, and When the cylindrical surface is in contact with the workpiece, the tool radius type of the tool offset number is used as a reflection target.
In the numerical control apparatus according to the positional embodiment of the present invention, the machining simulation unit is configured such that, if a vector of the tool in the tool length direction and a vertical vector of the workpiece at the contact point are substantially parallel, It is characterized in that it is determined that the bottom surface has come into contact with the work.

According to the present invention, it is possible to provide a numerical controller that automatically determines where to reflect workpiece measurement results.

It is a figure explaining the conventional numerical controller. 2 is a diagram showing a hardware configuration example of the numerical controller 1; FIG. 2 is a diagram showing an example of the functional configuration of the numerical controller 1; FIG. 4A and 4B are diagrams for explaining the operation of a machining simulation unit 101; FIG. 4A and 4B are diagrams for explaining the operation of a machining simulation unit 101; FIG. 4A and 4B are diagrams for explaining the operation of a machining simulation unit 101; FIG. 4A and 4B are diagrams for explaining the operation of the measuring unit 102; FIG. 4 is a diagram illustrating an example of a workflow using the numerical control device 1; FIG. 4 is a diagram illustrating an example of a workflow using the numerical control device 1; FIG. 4 is a diagram illustrating an example of a workflow using the numerical control device 1; FIG. 4 is a flow chart showing the operation of the numerical controller 1; 4 is a flow chart showing the operation of the numerical controller 1;

The numerical control apparatus 1 according to the present embodiment uses the machining simulation function to theoretically specify the tool that was used during machining of the measurement position, so that the tool offset location ( offset number and type) is determined automatically.

FIG. 2 is a schematic hardware configuration diagram showing main parts of the numerical controller 1 according to the embodiment. The numerical control device 1 is a device that controls industrial machines including machine tools. The numerical controller 1 has a CPU 11 , ROM 12 , RAM 13 , nonvolatile memory 14 , bus 10 , axis control circuit 16 , servo amplifier 17 , interface 18 and interface 19 . A servo motor 50 , an input/output device 60 and a measuring device 70 are connected to the numerical control device 1 .

The CPU 11 is a processor that controls the numerical controller 1 as a whole. The CPU 11 reads the system program stored in the ROM 12 via the bus 10 and controls the entire numerical controller 1 according to the system program.

The ROM 12 pre-stores, for example, a system program for executing various controls of the machine.

The RAM 13 temporarily stores calculation data, display data, data input by the operator via the input/output device 60, programs, and the like.

The nonvolatile memory 14 is backed up by, for example, a battery (not shown), and retains the stored state even if the power supply of the numerical controller 1 is cut off. The nonvolatile memory 14 stores data, programs, etc. input from the input/output device 60 . The programs and data stored in the non-volatile memory 14 may be developed in the RAM 13 during execution and use.

Axis control circuit 16 controls the motion axes of the machine. The axis control circuit 16 receives the movement command amount of the axis output from the CPU 11 and outputs the movement command of the operating axis to the servo amplifier 17 .

The servo amplifier 17 drives the servo motor 50 in response to the axis movement command output from the axis control circuit 16 .

A servo motor 50 is driven by the servo amplifier 17 to move the motion axis of the machine. The servomotor 50 typically incorporates a position/speed detector. The position/velocity detector outputs a position/velocity feedback signal, which is fed back to the axis control circuit 16 to perform position/velocity feedback control.

Although only one axis control circuit 16, one servo amplifier 17 and one servo motor 50 are shown in FIG.

The input/output device 60 is a data input/output device having a display, hardware keys, etc., and is typically an MDI or an operation panel. The input/output device 60 displays information received from the CPU 11 via the interface 18 on the display. The input/output device 60 passes commands, data, and the like input from hardware keys and the like to the CPU 11 via the interface 18 .

The measuring device 70 typically includes a measuring probe that is moved by a servomotor 50, and detects coordinate values when the measuring probe is brought into contact with a measuring point on the machined workpiece to determine the position of the machined workpiece. to measure the shape of Information output by the measuring device 70 is passed to the CPU 11 via the interface 19 .

FIG. 3 is a block diagram showing a characteristic functional configuration of the numerical controller 1. As shown in FIG. A typical numerical controller 1 has a machining simulation unit 101 , a measurement unit 102 , a machining tool identification unit 103 and a reflection unit 104 . The operation of each processing unit will be described with reference to the flowcharts of FIGS. 11 and 12. FIG.

The machining simulation unit 101 executes a machining simulation function (detailed description is omitted because it is a well-known technique) provided in the numerical control device 1 . The machining simulation may be performed in parallel with the machining of the workpiece, or may be performed before starting the machining. At this time, the machining simulation unit 101 sequentially adds data (1) and (2) shown below to the elements of the workpiece that are in contact with the tool.

(1) Tool surface (cylindrical surface/bottom surface) when the workpiece and tool are in contact
A work object drawn in the machining simulation function has a surface composed of a large number of minute elements (usually triangular objects). The machining simulation function forms the surface of the work object after cutting by updating the minute elements (S101 and S102) when the tool object and the work object come into contact (during work cutting).
A tool object drawn in the machining simulation function holds a direction vector a indicating the orientation of the tool. The machining simulation unit 101 determines the angle between the direction vector a and the vertical vector b of the minute element when updating the minute element (S104 to S106). As shown in FIG. 4, if the directional vector a and the vertical vector b are substantially parallel (the allowable angular difference can be set arbitrarily), the machining simulation unit 101 predicts the contact between the workpiece and the tool. The surface of the tool is determined to be the "bottom surface", that is, the tip of the tool (S107; see FIG. 5). Otherwise, it is determined that the surface of the tool is a "cylindrical surface", that is, the side surface of the tool (S108, see FIG. 6). The machining simulation unit 101 saves this determination result in association with the minute element object.

(2) Tool offset number (modal variable)
When updating the microelements, the machining simulation unit 101 associates the updated microelement object with data indicating the tool offset modal (modal information indicating the tool offset number) at the time of update and saves the data (S103-1, S103-2). The tool offset modal saved here includes an offset number for either the tool diameter or the tool length. Modal information (modal variables) means global variables that are valid within the command group.

The measurement unit 102 obtains the contact point between the measurement probe and the workpiece. During the machining simulation by the machining simulation part 101, the measurement unit 102 detects the contact point between the drawn probe object and the drawn work object when the measurement command is executed (on the actual work object that the probe is scheduled to contact when actually measuring later). position) is acquired (S109). This can be realized by known techniques. After that, the measurement unit 102 identifies a minute element of the work object corresponding to the contact point at the time of measurement (S110; see FIG. 7). Typically, the minute element closest to the position of the probe during measurement is identified. If the minute element is a triangle, select the minute element that minimizes the sum ax+bx+cx of the distance between the coordinate x of the probe and the three vertices a, b, and c.

The machining tool identification unit 103 identifies the tool used when machining the measurement position. The machining tool identification unit 103 acquires the tool offset number stored in association with the minute element identified as the contact point by the measurement unit 102, and the surface of the tool when the workpiece and the tool come into contact (S111 and S112). If the surface of the tool when the workpiece and the tool are in contact stored in the microelement is a "cylindrical surface", the machining tool identification unit 103 sets the tool radius type of the tool offset number to the measurement result reflection destination. and decide. On the other hand, if the surface of the tool when the work stored in the microelement and the tool come into contact is the "bottom surface", the tool length type of the tool offset number is used as the reflection destination of the measurement result (S113 to S115). ).

It should be noted that depending on the numerical control device 1, two offsets, an offset related to shape and an offset related to wear, may be set. In this case, the shape-related offset is used to compensate for individual differences in tools, and the wear-related offset is used to compensate for tool wear caused by repeated machining. In such a numerical control device 1, the machining tool specifying unit 103 uses an offset related to wear as a reflection destination. For example, by setting the (ideal) tool diameter before wear as R and the diameter reduced by wear as r, the actual tool diameter R′=R−r is used during machining. On the other hand, in the case of an optional configuration in which the offset is not divided by shape/wear, the processing tool specifying unit 103 makes the offset regarding the shape the reflection destination. For example, an actual tool diameter R' is held, and the decrease due to wear is reflected in R' at any time.

The reflection unit 104 reflects the measurement result in the reflection destination specified by the machining tool specifying unit 103 . First, the reflecting unit 104 actually performs machining of the workpiece according to the machining program and measurement of the workpiece after machining. After that, the reflecting unit 104 updates the tool offset value specified by the machining tool specifying unit 103 based on the work measurement result at the predetermined measurement point (S116). The destination is the tool offset value associated with the (closest) contact point corresponding to the actual measurement point. Since the method of reflecting the measurement result in the tool offset value is a known technique as described in Patent Document 1, for example, detailed description thereof will be omitted here.

<Example>
Using a specific example, the workflow seen from the operator when using the numerical controller 1 according to the embodiment of the present invention will be described.

(1) Input work shape data for simulation The operator inputs work shape data for simulation. FIG. 8 shows an example in which the operator inputs a rectangular parallelepiped workpiece having a width of 100, a depth of 100, and a height of 60. FIG.

(2) Machining program creation The operator creates a machining program. FIG. 9 shows an example in which the operator inputs a machining program for creating a workpiece having the shape shown in FIG.

(3) Insertion of measurement program A measurement program for measuring the workpiece after machining is inserted into the machining program created in (2) above. FIG. 10 is a diagram showing an example of the measurement program inserted into the machining program, in which G2040 is a macro-commanded measurement program. Of these, the part (argument) surrounded by a thick line indicates information that was required to be input in the conventional measurement program, but does not need to be input in the present embodiment. Conventionally, it was necessary to input a tool offset location (tool offset number and type) for indicating the reflection destination of the measurement result. In addition, A50. B100. . . , etc. are arguments indicating measurement conditions (moving speed, approach distance, etc. during measurement).

(4) Operation of Machining Program The operator actually runs the machining program to perform machining. At the same time, the numerical controller 1 starts executing the simulation by the machining program.

(5) Execution of measurement program Prior to actual operation, the numerical controller 1 executes a measurement program in machining simulation. At this time, the machining tool specifying unit 103 obtains the reflection destination (tool offset number and type) of the measurement result through the series of processes described above, and temporarily stores it in the memory.

After that, the numerical controller 1 executes the measurement program in actual operation. At that time, the reflection destination (the tool offset value of the contact point) obtained during the machining simulation is updated according to the measurement result.

According to the present embodiment, the numerical controller 1 automatically identifies the reflection destination of the measurement result, so that the operator can reduce the workload associated with manually setting the reflection destination.

1 numerical controller 11 CPU
12 ROMs
13 RAM
14 nonvolatile memory 18 interface 19 interface 10 bus 16 axis control circuit 17 servo amplifier 50 servo motor 60 input/output device 70 measuring device 101 machining simulation unit 102 measuring unit 103 machining tool specifying unit 104 reflecting unit

Claims (4)

A numerical control device that reflects the measurement result of the workpiece after machining to the tool offset value of the tool,
a machining simulation unit that executes a machining simulation and associates a contact point at which the tool and the workpiece come into contact with each other, a tool offset type at the time of contact, and a tool offset number at the time of contact;
The tool offset type and the tool offset number associated with the contact point between the tool and the workpiece in the machining simulation corresponding to the contact position between the measurement probe and the workpiece after machining as the reflection destination of the measurement result. a machining tool identification unit to be determined;
and a reflection unit that reflects the measurement result in the reflection destination. The machining simulation unit associates a contact point between the tool and the workpiece with a surface of the tool at the time of contact,
The machining tool specifying unit selects one face based on the surface of the tool associated with the contact point between the tool and the workpiece in the machining simulation corresponding to the position at which the measurement probe and the workpiece after machining are in contact. A tool offset type is selected, a tool offset number associated with the contact point is selected, and the tool offset type and the tool offset number are determined as the reflection destination of the measurement result. 2. Numerical controller according to 1. When the bottom surface of the tool is in contact with the work, the machining tool identification unit uses the tool length type of the tool offset number as a reflection destination, and when the cylindrical surface of the tool is in contact with the work, the 2. The numerical controller according to claim 1 , wherein the tool radius type of the tool offset number is used as a reflection destination. The machining simulation unit determines that the bottom surface of the tool is in contact with the workpiece when a vector of the tool in the tool length direction and a vertical vector of the workpiece at the contact point are substantially parallel. The numerical controller according to claim 1.

Images