JPS6165311A - Setting device for coordinate system of machine tool - Google Patents

Abstract

PURPOSE:To easily set the reference of work machining by compensating an error in the machining origin of NC data in the device on the basis of the measured value of a cutting position. CONSTITUTION:Position data XDP from a machining origin after trial grinding is a value read out by a tape reader 1, but contains an error actually. The difference between measured value data XIN and position data XDP is calculated by an arithmetic means 4, whose arithmetic result is stored in a data memory 7; and a correction value is read out of a correction data memory for each tool and a deviation in tool fitting is corrected in the device to facilitate work machining.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is an NC system that sets a plurality of tools on a tool post turret and automatically controls each tool by commanding the coordinate values of the machining position to each tool.
The present invention relates to a coordinate system setting device for a machine tool, and particularly relates to a coordinate system setting device for a machine tool that assigns numerical values based on the machining origin of NC data to a tool controlled by orthogonal coordinates based on the machine origin.

[Conventional technology]

In NC machine tools, workpiece machining coordinates and tool control coordinates can be used in common and are numerically compatible, unless their coordinate systems are of different types, such as orthogonal coordinates and polar coordinates. However, in reality, both the tool side and the workpiece side have delicate problems, and data cannot be exchanged straight. The problem on the tool side is that when multiple tools are placed on the tool post turret, the cutting edge position of each tool has a different installation deviation from the machine origin. Although a measurement method known as the so-called "measuring method" has been devised, there is still room for research into how to use it. The problem on the workpiece side is that the machining origin itself fluctuates relative to the machine origin due to the machining allowance and distribution of trial machining before machining. They had to rely on the inefficient method of micro-measuring the machined surface and recalculating the relative position with respect to the workpiece for each d tool.

[Problem that the invention seeks to solve]

In view of the problems described in -, an object of the present invention is to correct the machining origin error and tool installation deviation of NC data commanded to the workpiece within the device, thereby easily setting the workpiece machining standard. The aim is to provide a coordinate system setting device for machine tools and contribute to the automation and efficiency improvement of NC machining operations.

[Means and actions to solve the problem]

In order to achieve the above object, the present invention sets one of the tools as a reference tool, brings it into contact with the workpiece surface after trial cutting, captures the error between the NC data value and the actual measurement value, and makes the same The present invention is characterized in that each tool is brought into contact with the work surface, and the sum of the error value and the deviation value is used as a correction value for each tool to set the coordinate system.

〔Example〕

Hereinafter, the present invention will be explained in detail with reference to drawings and examples.

FIGS. 1A and 1B are explanatory diagrams showing the relationship between the work surface and the tool in the present invention. In both figures, a workpiece W is held by a chuck B and processed by a tool T having a machine origin δ on the side opposite to the chuck B. The chuck B can rotate while gripping the workpiece W with the Z-axis passing through the center of the mounting base H and perpendicular to the bracket base (■) as the rotation axis, and the coordinate axis direction of this machine tool is
and an X-axis in a direction perpendicular to the Z-axis.

The same figure (a) shows the correction regarding the radial direction X-axis, and the same figure (b) shows the correction about the end face cutting Z-axis, but the principle and procedure are the same. That is, after the trial cutting is completed, while keeping the cutting edge of the reference tool To in contact with the circumferential surface or the diameter end face of the workpiece, read the NC display value Xdp or Zdp from the machining origin A at the cutting edge position, and on the other hand, The actual value Xin or Zin is measured using a micrometer or the like. In addition, the NC display value Xdp and the actual measurement value Xi in the X-axis direction
It is assumed that n represents the diameter of the workpiece W. Also,
The actual measurement value Zin in the X-axis direction is the total length of the workpiece W in this embodiment, but the machining origin A is set appropriately, and in that case, it is determined as a value supported by the actual measurement value. . The difference values Xdp-Xin and Zdp-Zin between this display and actual measurement are the error X of
a and Z ofa, and for the reference tool To, Xofa = Xdp-Xin, which becomes the correction data as it is,
Zofa = Zdp - Zino Furthermore, the machine system coordinate values Xn and Zn of the cutting edge position of each other tool are set as the reference tool To
If the machine system coordinate values for the standard tool To are input as corrected standard values Xmof and Zmof, the difference value X between each tool and the standard tool is
n-X mol and Zn-Zmof are deviations for each tool, and this deviation is added to the error X ofa or Z o
The numerical value obtained by adding fa becomes the correction data Xofn and Zofn for each tool. Xofn=Xn−Xmof+Xo
fa, Zofn = Zn-Zmof+Zofa
In this case, the correction reference values Xmof and Zmof are
It is subject to the coordinate system setting with NC data, and can be further spread to each tool using the correction data X ofn and Z ofn, so it can be used for coordinate conversion and coordinate system setting, and the tool There is no need to use a presetter or the like.

FIG. 2(A) is a configuration diagram showing an example of a coordinate system setting device for a machine tool in which the present invention is implemented. In FIG. 2 (A), the coordinate system setting device includes a deep reader 1 for reading NC data, a keyboard with a screen 2 that is a means of inputting actual measured values from the machining origin to the cutting edge position, and transmitting position data from the machine origin. Means 3, first calculation means 4 for calculating the error between the actual measurement value and the NC data value, second calculation means 5 for calculating the deviation for each tool and calculating a correction value, and calculating the position data of the reference tool. A reference tool setting memory 6 for registering as parameters, a correction data memory 7 for storing each calculated correction value as a table, a program memory 8 for temporarily storing NC data, and a compatibility data for a desired coordinate system. The keyboard 2 with a screen includes a coordinate system setting data memory 9 to store and a central processing unit CPU10, and as shown in FIG. Numeric keys 239 Function keys 24. It is composed of a cursor key 25, a power switch 26, and the like.

FIG. 4 is a flowchart 1 showing an example of the operation of the coordinate system setting device described above. Since the operation flow is almost the same for the X-axis and the Z-axis, only the X-axis will be explained here. In Fig. 4, after trial cutting is completed as stage 0, the reference tool is brought into contact with the work surface as shown in Fig. 1 (a) as stage 0, and as stage 0, the selection button on the keyboard with screen shown in Fig. 3 is pressed. When you press , the screen shown in the figure is selectively displayed.

Therefore, in the 0th stage of the flow, when the numerical value of the workpiece diameter actually measured with a micrometer, etc. is pressed, the Xin shown as the keyboard input value in Figure 2 (A) is taken in, and at the same time it is displayed on the screen as NC data. Xdρ, which had been previously calculated, is also taken in as the work system current value in FIG. 2(A) at the 0th stage. Next, at the 0th stage, the current tool cutting edge position is taken in as the mechanical system current value Xn shown in FIG. 2(a) based on the feedback information of the motor. After the above inputs are completed, each signal automatically flows through the circuit, and the first arithmetic circuit 4 inputs the 0th signal of the flow.
As a step, the calculation of the error is performed, and the calculated error X
Ofa is stored in the 0th stage in the X term of the correction data memory 7 shown in FIG. Next, in order to perform correction calculations for other terms, when the signal from the mechanical system current value memory of the reference tool is confirmed by the AND circuit, the X correction reference value Xm is obtained as it is at the 0th stage.

It is registered in memory as f. Next, the measurement for each tool is started, and in the [phase] step, each tool is brought into contact with the work surface, and in the 0th step, the selection button on the screen keyboard is pressed to call up the shift screen for the tool number. Then, when the button is pressed, the cutting edge position of the tool is taken in as the mechanical system current value Xn in FIG. The X correction value X ofn for each tool by calculating the deviation and adding the work error is calculated in the 0th stage, and the X term of the tool in the correction data memo 7 in Figure 2 (A) is calculated in the 0th stage is assigned to

By repeating this procedure for the X terms and 2 terms of all tools set in the tool post turret, the correction data memory 7 is completed. Figure 5 is a sample diagram showing an example of reading out the contents of the correction data memory on the CR7 screen. Since the deviation value for the floor 1 tool, which is the standard tool, is zero, the X term and the 2 term are workpiece errors. X ofa and Z
This will indicate ofa. In addition, in the screen, the R term indicates the sharpness by the radius of the cutting edge, and the M term is a flag for identifying the standard tool, in this case only for tools with No. 1
” is set up. The T term is an identification number of the blade edge position when a touch sensor is used.

Fig. 6 is a configuration diagram showing an example of a touch sensor, in which a sensor P is arranged on the fixed side of a machine tool, and a closed circuit is formed the moment a workpiece W and a tool T come into conductive contact. The current flowing through the circuit is detected by electromagnetic induction or the like, and the signal is used in place of the input button on the keyboard with screen. Naturally, this simplifies work and speeds up operations. FIG. 2(b) is a configuration diagram showing an example of the coordinate system setting device of the present invention when using this sensor. The configuration of the coordinate system setting device in FIG. 2(b) is mostly the same as that already explained in FIG. 2(b), but the touch sensor 11 is connected to a bus, and the contact signal is X
Alternatively, only the selected side of Z passes through the AND gate and participates in the adoption of the mechanical system current value. In the flowchart in Figure 4, the input button is omitted by the operation in the 0th stage.
There is no change in the flow, only B8 is executed.

As mentioned above, once the correction data memory 7 is complete, as explained in principle, the correction values can be used to freely convert the coordinates and set the coordinate system, and the tool presetter etc. can be used. There's no need to.

〔Effect of the invention〕

As explained above, according to the present invention, after trial cutting is performed on the workpiece, the error regarding the machining origin of the NC data and the tool installation deviation are used as the reference for determining the correction of other tools using the cutting position. The present invention provides a coordinate system setting device for machine tools that allows correction within the device and easily sets standards for workpiece machining, which greatly contributes to the automation and efficiency improvement of NC machining operations.

[Brief explanation of drawings]

Figures 1 (a) and (b) are explanatory diagrams showing the relationship between a workpiece and a tool, Figures 2 (a) and (b) are block diagrams of an embodiment of the coordinate system setting device according to the present invention, and Figure 3 is an explanatory diagram showing the relationship between a workpiece and a tool. FIG. 4 is a front view of the keyboard with screen, FIG. 4 is a flowchart of the operating procedure of the present invention, FIG. 5 is a sample diagram of an example of reading out the correction data memory, and FIG. 6 is a configuration diagram of the touch sensor. W---Work, T-Tool, A-Machining origin, δ-・Machine origin, Xdp, Zdp-NC data value, X in,
Z in - Actual measurement value, Xn, Zn - Mechanical system current value, X
mof. Zmof-correction reference value, Xofn, Zofn-correction data value, ■-tape reader, 2-manual means, 3...
Position data sending means, 4-first calculation means, 5-second calculation means, 6-reference tool setting memory, 7-correction data memory, 8-cannibal program memory, 9-coordinate system Setting data memory, 10--Central control unit, 1
1-Touch sensor.

Claims (1)

[Claims] A machine in which one or more tools are set on a tool post turret and NC data based on the machining origin is assigned to a machine tool that controls the machining position of each tool using orthogonal coordinates based on the machine origin. A coordinate system setting device for a machine, which includes a reference tool setting memory that registers one of the tools as a reference tool, and the actual measured value from the machining origin to the cutting edge position when the reference tool is brought into contact with the work surface after trial cutting. an input means for inputting a value, a first calculation means for calculating an error value between the actual measurement value and the NC data value, a measurement means for bringing each tool into contact with a workpiece surface and reading a mechanical system coordinate value, and the reference tool. a second calculation means for calculating a correction value for each tool by adding the error value to a deviation value between the mechanical system coordinate value of and the mechanical system coordinate value for each tool; and storing each calculated correction value. 1. A coordinate system setting device for a machine tool, comprising: a correction data memory for controlling the above-mentioned means; and a central processing unit for controlling each of the above-mentioned means.