KR20060075304A - A tool error detection unit of cnc main axis and method thereof - Google Patents

Abstract

The present invention relates to a tool abnormality detection device and method of the spindle load to mount the overload data according to the tool, the material, the pallet and the machining process in advance and to properly respond to the overload condition compared to the current overload due to the tool breakage,

Numerical control part, spindle motor device, servo motor device, machine control part, abnormal overload detection device, which receives abnormal overload condition from the machine control part, and receives the current from the numerical control part to the spindle motor device and servo motor device. It is characterized by detecting the overload and no-load status of the servomotor device and the spindle motor device by comparing the load generation value with the reference condition and the current overload condition.

It is possible to have separate load measurement test data for the same tool according to the pallet and material, and to have separate load measurement test data for the same tool according to the machining process. The present invention provides an advantage that it can respond appropriately to and can effectively measure the no load.

Spindle, load, tool, abnormal

Description

A tool error detection unit of CNC main axis and method thereof

Figure 1a is a graph of the load on the X axis in the cutting feed only Y axis.

1B is a graph of Y-axis load during cutting feed of only Y-axis.

Figure 3c is a graph of the Y-axis load during the XY axis cutting feed.

Figure 4 is a graph showing the no-load time during cutting feed of the present invention.

Figure 5 is a block diagram showing an embodiment of the present invention overload detection device.

6 is an operational flowchart of the present invention.

Explanation of symbols on the main parts of the drawings

10: numerical control unit

20: servo motor device

30: spindle motor unit

40: machine control unit

50: abnormal overload detection device

The present invention relates to a tool abnormality detection device and method of the spindle load, in particular, the overload data according to the tool, material, pallet and machining process in advance, and compared to the current overload due to the tool breakage to properly respond according to the overload conditions In addition, the present invention relates to a tool abnormality detection device and method for detecting a spindle load, characterized in that to accurately check the no-load condition by measuring and recording a spindle no-load occurrence time during normal stone cutting.

Machine tools for cutting or machining materials typically have one or more servomotors for feeding the workpiece and spindles equipped with tools for cutting the materials carried by the servomotors. Equipped with.

Then, the tool mounted on the spindle cuts the material while the material is transported by the servomotor in a predetermined path. In this case, if the tool is excessively worn or damaged, the cutting operation may not proceed smoothly and the machine tool is overloaded.

Conventionally, in order to detect such an overload, an external sensor or a CNC (Computer Numerical Control) controller uses a method of detecting load current values of a spindle motor and a servo motor.

That is, assuming that an abnormal overload or no load occurs in case of a tool abnormality, it is determined whether the value of the current supplied to the spindle motor or the servomotor exceeds the reference maximum value and the overload is detected and supplied to the spindle motor or the servomotor. The low load was detected by judging whether the value of the current to be output is below a reference value.

At this time, in order to allow the overload detection to be performed only in the thread cutting section, the load of the spindle motor is detected for the section except the acceleration / deceleration section for conveying the material, and the load of the servo motor is excluded except for the rapid traverse section and the acceleration / deceleration section. It is detected for a section.

By the way, since the X-axis and Y-axis are often moved at the same time in the servo motor for transferring the pallet, interference occurs when measuring the axial load.

That is, only the X-axis affects the Y-axis even during cutting feed, which gives a constant load on the Y-axis, and when the Y-axis only cuts, it has the same effect on the X-axis. The load value and the actual cutting load are displayed on each axis at the same time, so the load measurement graph of one axis is very irregular. FIG. 1A shows the X-axis load at the cutting feed only in the Y axis, FIG. 1B is the Y-axis load at the cutting feed only in the Y axis, and FIG. 3C is the Y-axis load during the cutting feed in the XY axis.

Therefore, since the data input through the servomotor shaft interfere with each other, the measurement data of no load is almost meaningless.

That is, even if one axis satisfies the no-load condition, it is determined that it is not finally no-load because the load factors generated from the other axis come in.

In addition, even when machining using the same machining program tool, an error of about 40% in the XY axis and about 10% in the spindle and the Z axis may occur depending on the pallet change or the material set-up state. 2A is a Y-axis machining load by pallet A, and FIG. 2B is a Y-axis machining load by pallet B. As a result of measuring the machining load of the Y-axis that occurs during simultaneous XY-axis machining with the pallet changed, It's coming out.

For this reason, it is very difficult to set the range of load measurement and abnormal load as a parameter because several pallets must be processed to measure the range of normal cutting load.

Unlike the lathe, machining center tooling system (MCT) is not common to detect the abnormality of the tool by measuring load because the spindle reflects the actual cutting load.

3 shows the measured loads at various steps and depths of cut by a single tool.

That is, various loads having different peaks are generated, and as shown, load conditions having three different heights occur in the embodiment, but conventionally, only the highest height load is used as the reference point.

Therefore, in the embodiment, if only the first load is used as a reference, the second load and the third load may be judged to be no abnormality if the first load condition is satisfied even if the second load and the third load are exceeded. If the smooth load condition is not satisfied, and the second load condition and the third load condition are exceeded, there is a problem of tool breakage.

The object of the present invention is to improve the prior art as follows.

First, with respect to the problem of the prior art that the X-axis and Y-axis interfere with each other by the machine structure, the present invention is to detect the no-load when the tool breaks by measuring only the overload and measuring the non-cutting feed time for the main axis Detect.

Second, with respect to the problem of the prior art in which load deviation occurs for the same program and tool according to the setup state of the pallet and the material, the present invention has separate load measurement test data even for the same tool according to the pallet and the material. To select the load data group.

Third, the present invention has the problem of detecting the wear of the tool by detecting the abnormal load only on the main shaft. Select the load data group and change the inspection reference value in the part program by G code.

As a means for achieving the above object,

The present invention includes a numerical control unit for receiving the machining program according to the operator's instructions and instructs the rotational speed and the rotation time of the servo motor and the spindle motor in accordance with the machining program command; A servo motor device which rotates in response to a power input according to a command of the numerical control unit, transfers the pallet to the XY axis, and contacts the workpiece with the tool so that processing is performed; A spindle motor device for processing a workpiece by rotating a tool according to a power input according to a command of the numerical controller; A machine control unit which issues various operation commands to the machine according to the command of the numerical control unit, informs the numerical control unit of the machine signal from the machine tool, and controls the operation sequence of the machine tool; The machine controller receives input of the tool, each material, pallet, and load conditions according to the machining process from the machine control unit, and detects non-contact cutting by measuring the non-cutting feed time for the overload or the spindle, and sends an alarm signal to the machine controller. It is characterized by including an abnormal overload detection device for outputting.

In addition, the mechanical control unit is characterized by having a separate load measurement test data for the same tool according to the pallet and the material.

In addition, the mechanical control unit is characterized in that it has a separate load measurement test data for the same tool according to the machining process.

In addition, the step of measuring and recording the time that the no-load of the main shaft occurs during the cutting feed during normal cutting in accordance with each material and tool; Measuring and recording load data satisfying respective conditions according to a pallet, a material, and a processing process input to the processing; Measuring an overload of the servo motor and the spindle motor when the machining operation starts; Selecting load data group by M code and receiving load information according to a corresponding spindle tool and a cutting situation; Comparing the overload information of the servo motor and the spindle motor currently measured with the information of the input M code and determining that an overload has occurred when the current spindle tool load is greater than the normal load + spare amount of the spindle tool, and outputting an alarm; Checking whether no load is generated during cutting, if it is determined that the load is not overloaded; When the tool cutting time takes longer than the no-load time + the spare value, it generates a alarm.

Other objects, specific advantages and novel features of the present invention will become more apparent from the following detailed description and the preferred embodiments associated with the accompanying drawings.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. First of all, in adding reference numerals to the components of each drawing, it should be noted that the same reference numerals are used as much as possible even if displayed on different drawings. In addition, in the following description of the present invention, if it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted.

5 is a configuration diagram showing an embodiment of the present invention overload detection device, the configuration of the present invention is largely the numerical control unit 10, the servo motor device 20, the spindle motor device 30, the machine control unit ( 40 and the abnormal overload detection device 50, the overload detection device 50 receives the abnormal overload condition from the machine control unit 40, and the spindle motor unit 30 and the servo from the numerical control unit 10. The load generation value is input from the current sent to the motor device 20, and the overload and no-load state of the servomotor device 20 and the spindle motor device 30 are detected by comparing the reference condition with the current overload condition.

The biggest feature of the present invention is to detect only the overload from the servo motor device 20 and to measure the non-cutting feed time with respect to the axis from the spindle motor device 30 to detect no load when the tool breaks, according to the pallet and material Even if the same tool has separate load measurement inspection data, the load data group can be selected by M code. Also, the same tool has separate load measurement inspection data according to the machining process. Select and change the inspection standard value in the part program by G code.

First, the numerical control unit 10 of the present invention receives a machining program according to the operator's instructions, and converts the rotational speed and the rotation time of the servo motor and the spindle motor into an electric supply amount according to the machining program command to give a rotation command.

The servo motor device 20 rotates at a predetermined speed for a predetermined time according to the power input according to the command of the numerical control unit 10 to transfer the pallet to the XY axis so that the work is made by contacting the workpiece with the tool.

The spindle motor 30 also processes the workpiece according to a predetermined program while contacting the workpiece by rotating the tool at a predetermined speed for a predetermined time according to the power input according to the command of the numerical control unit 10.

The machine control unit 40 issues various operation commands to the machine according to the command of the numerical control unit 10, informs the numerical control unit of the machine signal from the machine tool, and controls the operation sequence of the machine tool.

The abnormal overload detection device 50 receives a load input according to a tool, each material, a pallet, and a machining process, which are input to the machine, from the machine controller 40, and is also provided to the spindle motor device 30. Determining whether the overload according to the tool has occurred in the motor, and outputs an alarm signal to the machine control unit when the overload occurs, and also measures the non-cutting feed time for the main shaft to detect no-load due to tool breakage.

Hereinafter, the present invention will be described in more detail.

In the present invention, only the overload is detected from the servomotor device 20 and the non-cutting feed time is measured from the spindle motor device 30 to detect no load at the time of tool breakage.

That is, in the servomotor device 20, the X-axis and the Y-axis are influenced and received by each other, so the signals overlap, so even if either side is under no load condition, the signal is output from the other side and the signals overlap with each other. Since no load detection is almost impossible through the device 20, the present invention measures the non-cutting feed time of the spindle motor device 30 and compares it with the signal detection of the servomotor device 30 to detect no load.

Figure 4 shows the no-load time during the cutting feed of the present invention, as shown in Figure A portion shows the no-load time, the no-load time of the main axis is accurately measured on the graph, where the measured time and the pre-input Comparing the no-load time allows you to measure the exact no-load condition of the tool.

As a result, the present invention measures and records the time at which the no-load of the spindle occurs during the cutting feed during normal cutting in order to detect the no-load separately according to each material and the tool. As it is judged, more accurate no-load detection is achieved.

In addition, the overload detection device 50 of the present invention receives the normal load value for each tool to the machine control unit 40, and receives each load value changed during the work of one workpiece.

Thereafter, the overload information is received from the spindle motor device 30 and the servomotor device 20 and compared with the overload information input from the machine control unit.

The abnormal overload detection device 50 compares the normal load value of the tool output from the machine control unit with the load value input from the main shaft motor, and outputs an alarm when the current input load exceeds a preset load value.

6 is an operation flowchart of the present invention.

Measuring and recording the time at which the no-load of the spindle occurs during the cutting feed during normal cutting according to each material and tool;

Measuring and recording load data satisfying respective conditions according to a pallet, a material, and a processing process input to the processing;

Measuring an overload of the servo motor and the spindle motor when the machining operation starts;

Selecting load data group by M code and receiving load information according to a corresponding spindle tool and a cutting situation;

Comparing the overload information of the servo motor and the spindle motor currently measured with the information of the input M code and determining that an overload has occurred when the current spindle tool load is greater than the normal load + spare amount of the spindle tool, and outputting an alarm;

Checking whether no load is generated during cutting, if it is determined that the load is not overloaded;

An alarm is output when the tool non-cutting time takes longer than the no-load time + allowance value.

As described above, the present invention has separate load measurement inspection data for the same tool according to the pallet and material, and also has separate load measurement inspection data for the same tool according to the machining process. By selecting and applying it, it provides the advantage that it can respond appropriately to overload and can effectively measure the no-load.

Although the present invention has been described in connection with the above-mentioned preferred embodiments, various other modifications and variations may be made without departing from the spirit and scope of the invention. Accordingly, it is intended that the appended claims cover such modifications and variations as fall within the true scope of the invention.

Claims (4)

A numerical control unit 10 which receives a machining program according to a worker's instruction and instructs a rotational speed and a rotation time of the servomotor and the spindle motor according to the machining program command; A servomotor device 20 which rotates in response to a power input according to a command of the numerical controller 10 to transfer the pallet to the XY axis, thereby bringing the workpiece into contact with the tool so that the machining is performed; Spindle motor device 30 for processing the workpiece by rotating the tool in accordance with the power input according to the command of the numerical control unit 10; A machine control unit (40) which issues various operation commands to the machine according to the command of the numerical control unit (10), informs the numerical control unit of the machine signal from the machine tool, and controls the operation sequence of the machine tool; The machine control unit 40 receives the tool input to the machining, the material, the pallet, and the load conditions according to the machining process, respectively, and detects the non-contact cutting by measuring the non-cutting feed time for the overload or the spindle. Tool abnormality detection device for a spindle load, characterized in that it comprises an abnormal overload detection device (50) for outputting an alarm signal. The method of claim 1, The machine control unit 40 is a tool abnormality detection device of the main shaft load, characterized in that having a separate load measurement test data for the same tool according to the pallet and the material. The method of claim 1, The machine control unit 40 is a tool abnormality detection device of the main shaft load, characterized in that having a separate load measurement test data for the same tool in accordance with the machining process. Measuring and recording the time at which the no-load of the main shaft occurs during the cutting feed during the normal cutting according to each material and the tool (S10); Measuring and recording load data satisfying respective conditions according to a pallet, a material, and a processing process input to the processing (S20); Measuring an overload of the servo motor and the spindle motor when the machining operation starts (S30); Selecting load data group by M code and receiving load information according to a corresponding spindle tool and a cutting situation (S40); Comparing the overload information of the currently measured servomotor and spindle motor with the input M code information, if the current spindle tool load is greater than the normal load + spare amount of the spindle tool, it is determined that the overload has occurred and outputs an alarm (S50). Wow; If it is determined in the step that it is not an overload step (S60) to check whether no load occurs during cutting transfer; The tool abnormality detection method of the main shaft load, characterized in that the sequential progress consisting of the step (S70) outputting an alarm when the tool non-cutting time takes longer than the no-load time + the margin value.

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