WO2020149316A1

WO2020149316A1 - External processing system for machine tool

Info

Publication number: WO2020149316A1
Application number: PCT/JP2020/001121
Authority: WO
Inventors: 憲吾山本; 貴行山内; 村上　浩二
Original assignee: 株式会社山本金属製作所
Priority date: 2019-01-15
Filing date: 2020-01-15
Publication date: 2020-07-23
Also published as: JPWO2020149316A1

Abstract

[Problem] The purpose of the present invention is to provide an external processing system for a machine tool, the external processing system being capable of modifying an operation control of a machine tool having a machining tool for machining a workpiece, the modification being made from outside of the machine tool. [Solution] This external processing system comprises: a measurement means that detects, in real time, a physical change in a machining tool, in a tool holder coupled to a main shaft of a machine tool by which the machining tool is gripped, or in the machine tool, and that then transmits data pertaining to the detection to the outside; an operation control means for a machine tool provided to the machine tool, the operation control means controlling the operations of the machine tool, the machining tool, and the tool holder; and an external control means provided outside of the machine tool. The external control means has: a reception means that receives data from the measurement means through wireless bidirectional communication; and an external control means that modifies, on the basis of the data from the measurement means as received by the reception means, a normal operation control of the machine tool and the machining tool that is performed by the operation control means.

Description

Machine tool external processing system

The present invention relates to an external processing system for changing an operation control program of a machine tool for processing a workpiece by a rotary processing tool such as a drill or an end mill or a processing tool such as a rotary tool in friction stir welding by interrupt processing or the like by an external personal computer or the like. Regarding

In machine tools such as machining cutting equipment, in order to improve machining accuracy and prevent tool damage, it is necessary to evaluate the wear, fatigue, damage, and chatter of the tool during actual machining. However, in the past, tool evaluations have been performed by equipment manufacturers and tool manufacturers for each equipment and tool, and are based on general evaluation criteria and academically standardized evaluation criteria. Real-time verification of the tool was not completed.

On the other hand, the applicant has developed and provided a tool holder unit for machine tools that can measure the temperature and acceleration of a rotating tool during processing, and has also developed and provided technology for predicting abnormalities such as tool damage based on the measurement results. (Patent Documents 1 to 3). This technique is advantageous in that the physical change of the tool during machining can be detected in real time, and the abnormality can be detected by an external device (such as a personal computer) that can wirelessly communicate with the tool or the machine tool.

However, the conventional technology has been able to detect only tool abnormalities and abnormal signs, and has not yet provided a specific configuration for controlling the operation of the machine tool after detection. Further, the machine tool is located at a position other than the tool or the tool holder for gripping the tool, for example, an acceleration pickup or a displacement meter arranged on the spindle of the machine tool, the current or torque of the spindle motor, or xyz on which the workpiece is mounted. When measuring various physical changes such as the current and torque of the dynamometer and servo motor near the stage, combine these measurement data with the measurement data of the tool to detect abnormality of the tool and control the operation of the machine tool with an external device. It would also be desirable to be provided with a configuration that does.

International Publication WO2015-022967 International Publication WO2016-136919 JP, 2018-54611, A

The present invention was created in view of the above circumstances, and an external device that measures a physical change of a processing tool such as a tool of a machine tool that processes a work, receives the measurement data, and determines an abnormality, etc. An object is to provide an external processing system that changes the operation control of a machine.

To achieve the above object, the external processing system of the present invention is an external processing system capable of externally changing the operation control of a machine tool having a processing tool for processing a workpiece.
A machining tool, a tool holder that grips the machining tool and is connected to a spindle of a machine tool, or a measuring unit that detects a physical change of the machine tool in real time and externally transmits the data.
An operation control means dedicated to the machine tool, which is provided in the machine tool and controls the operation of the machine tool, the machining tool and the tool holder,
An external control means provided outside the machine tool,
The external control means includes receiving means for receiving data from the measuring means by wireless bidirectional communication, and the machine tool and the machining tool by the operation controlling means based on the data from the measuring means received by the receiving means. And/or external control means for changing the normal operation control of the processing tool.

In the present invention, the measurement data from the machining tool being machined can be received/analyzed by the external device, and the operation of the machine tool can be changed in real time based on the result. Specifically, when an external device such as a laptop computer detects an abnormality in the processing tool from the measured data of temperature and acceleration, it shifts the operation of the machine tool to a subprogram that commands an operation different from normal operation, An interrupt signal is given from an external device to a computer numerical control (CNC (Computer Numerical Control) program (NC program)) originally built in the machine tool itself. Although it remained, the change of the operation of the machine tool can be instructed from the external PC even when the abnormality of the processing tool is detected, and the operation of the machine tool can be avoided while avoiding the abnormality that occurred in real time As a result, it is possible to achieve safe and highly accurate machining regardless of the machine tool, machining tool, workpiece, and machining conditions. Is also easy to set, and it is possible to raise the conditions to the last minute.

Further, as an example, the external control unit determines whether or not the data from the measuring unit is within a predetermined allowable range, and if the data is outside the allowable range, changes the normal operation control by the operation control unit. An interrupt signal is transmitted to the operation control means.

Specifically, the operation control means registers another control mode that is different from normal when changing the normal operation control by the operation control means, and changes the normal operation control by the operation control means from the external control means. When the interrupt signal is received, it is preferable to execute another registered control mode instead of the normal control mode.

Specifically, according to this example of the external processing system, the permissible range (threshold value, etc.) of the measured values of the processing tool and the like is set in advance, and the processing tool is processed by an external control means such as a personal computer that receives and analyzes the measured data. When the measured value is out of the allowable range, an interrupt signal is sent to the operation program of the machine tool to execute the subprogram in order to change the machine tool from the normal operation.

As another example, the measuring unit has a sensor for detecting at least temperature and/or acceleration data in the processing tool or the tool holder, and wirelessly transmits data from the sensor to an external control unit.
When the external control means determines that the data from the sensor has exceeded a preset threshold value as an abnormality of the machining tool, it stops the operation of the machining tool and the tool holder, and a warning lamp included in the machine tool. The normal operation control by the operation control means is changed to turn on. In addition, when it is determined that the preset threshold value is exceeded, the normal operation control by the operation control means may be changed so that the warning light of the machine tool is turned on. You may display a warning.

This external processing system example is a case of arranging a temperature sensor such as a thermocouple or an acceleration sensor in a machining tool or a tool holder that holds the processing tool in advance, and wirelessly transmitting measurement data to an external control unit such as a laptop computer. When the measured data exceeds a predetermined threshold value by the external control means, it is determined to be abnormal, the machining is immediately stopped, a warning light of the machine tool is turned on, and a subprogram for notifying the operator of the abnormality is interrupted.

Further, the measuring means has a sensor for detecting temperature data of at least the processing tool in the processing tool or the tool holder, wirelessly transmits temperature data from the sensor to an external control means, and the external control means, When it is determined that the temperature data from the sensor has exceeded a preset threshold value as an abnormality of the machining tool, the operation of the machine tool and/or the machining tool and the tool holder is stopped, and after the operation is stopped. When the temperature data from the sensor is below or below a preset temperature value as the threshold value or the temperature for restarting operation, when the operation of the machine tool, the machining tool and the tool holder is stopped The normal operation control by the operation control means may be changed so that the processing is restarted.

While the temperature near the cutting edge of the processing tool rises and the processing accuracy of the workpiece decreases, this interrupt control enables accurate and direct detection of how heat accumulates near the cutting edge and the sharpness of the cutting edge. Since defective machining can be avoided, more precise machining can be ensured. In particular, the value of the load on the rotary spindle motor (load meter value) that is usually included in machine tools may decrease if the workpiece softens due to overheating. Is advantageous because it is not possible to sufficiently avoid processing defects due to overheating near the cutting edge.

As still another example, the measuring means has a tool sensor for detecting at least temperature and/or acceleration data in the processing tool or the tool holder, and wirelessly transmits the data from the tool sensor to an external control means. In addition, the machine tool has a machine tool sensor for detecting data of physical change of each part of the machine tool, and transmits data from the machine tool sensor to an external control means,
When the external control means determines that the data from the tool sensor and the machine tool sensor is outside the preset allowable range as a machining tool abnormality, the operation control means causes the machine tool and the machine tool to operate. It is also preferable to change the normal operation control of the processing tool to another predetermined operation control.

This external processing system not only measures the temperature and acceleration of machining tools and tool holders, but also combines the measurement data of physical quantity changes in other parts of the machine tool with external control means to detect machining tool abnormalities, etc. Change the operation of the machine. For example, it is possible to detect abnormalities by combining the power and torque of the spindle motor for spindle rotation, the measurement data from the acceleration sensor and displacement sensor installed on the spindle, and perform more detailed abnormality determination and external operation control of machine tools. Becomes

According to the external processing system of the present invention, when the measurement result of the physical change during the machining of the machining tool such as the tool of the machine tool is wirelessly received in real time by the external device and the abnormality is judged by the external device, , An interrupt signal can be transmitted to an operation program (NC program) of a machine tool in order to eliminate abnormalities and the like, and operation control different from usual can be performed.

It is the schematic diagram which showed the outline of the external processing system of the machine tool of this invention. It is an example of the processing flow in the external processing system of the machine tool of the present invention, (a) shows an example of the processing flow in the external personal computer, (b) shows an example of the processing flow of the NC program for controlling the operation of the machine tool. It is another processing flow example in the external processing system of the machine tool of this invention, (a) shows the processing flow example in an external personal computer, (b) shows the processing flow example of the NC program which performs operation control of a machine tool. ..

The outline of the external processing system of the machine tool of the present invention described above and a specific processing flow example will be described below.

FIG. 1 shows an outline of an example in which the external part control means controls the operation change of the machine tool operation control means in the external processing system. The machine tool 10 is equipped with a tool holder 3 that holds the machining tool 1 by its main spindle 4, and rotates the main spindle 4 to rotate the machining tool 1, which is mounted on a stage 5 that moves in the XYZ directions. The cutting of the workpiece 2 is performed. The spindle 4 is rotated by a spindle motor, the spindle motor is controlled based on a CNC program, and the stage 5 is driven by a servo motor, and similarly controlled based on a CNC program.

The CNC of the machine tool 10 can be set and confirmed on the operation panel 7 of the machine tool 10. In addition to this, the CNC program can be transmitted to the external personal computer 8 via a wired LAN such as Ethernet. The CNC program is a program for controlling the operation of the machine tool 10 based on the variable (CNC) of the control numerical information of the machine tool 10, and the CNC is the coordinate (for example, XYS coordinate) and the number of the machining tool 1 (for example, the tool number). ), whether or not machining is being performed (for example, whether or not cutting feed is being performed), the program number being machined, the line number being machined, and the like.

Further, in the tool holder 3, as shown in Patent Document 1, temperature information from the thermocouple 6 in the machining tool 1, acceleration information from an acceleration sensor (not shown) in the machining tool 1 (or the tool holder 3), and the like. A transmission unit for wirelessly transmitting the data to the outside is provided, and temperature information and acceleration information during processing are wirelessly transmitted to the external personal computer 8 in real time by Wi-Fi, Blue-tooth, wireless LAN, or the like.

The CNC program wire-transmitted to the external personal computer 8 and the temperature/acceleration etc. information of the machining tool 1 wirelessly transmitted are processed by the external personal computer 8 as a time chart on the same time axis, and an abnormality such as damage of the machining tool 1 occurs. When is detected, for example, the warning light 9 is turned on to call attention. At this time, a warning can be simultaneously displayed on the display of the external personal computer 8.

Furthermore, according to this external processing system, not only the abnormality detection but also the actual processing control processing can be performed by the external personal computer 8. When an abnormality is detected, an interrupt signal is sent by wire from the external personal computer 8 to the CNC program, and the variables of the CNC are written so as to change and control the operation of the machine tool 10, its spindle 1, and the stage 5. Specific examples will be shown below.

First, a control example in which the machining operation of the machining tool 1 is suddenly stopped at the moment when the interference/collision is detected due to the temperature of the machining tool 1 or the acceleration (/force) received by the tool holder 3, and the machining tool 1 is retracted from the workpiece 2. Is illustrated. An example of the processing flow is shown in FIG. 2, (a) shows an example of the processing flow in the external personal computer 8, and (b) shows an example of the processing flow of the NC program for controlling the operation of the machine tool 10. On the external personal computer side, as shown in (a), when the process (ST1) is started, the external personal computer 8 reads temperature information from the thermocouple 6 and acceleration information and stress information from the acceleration sensor in the tool holder 3. (ST2).

Next, it is determined whether the temperature, acceleration, and force read in the external personal computer 8 reach the threshold value (ST3). As the threshold value, temperature, acceleration, and force as signs of damage to the processing tool 1 are preset according to the processing conditions.

If the temperature, acceleration, and force are above the threshold, it is determined that interference or collision has been detected, and an interrupt signal for changing the NC program to perform a sudden stop of the machine tool 1 or a retracting operation of the machining tool 1 from the workpiece 2 is issued. It is transmitted (ST4). Then, when the processing is completed and it is not necessary to continue the measurement (ST5), the processing is completed (ST6).

Further, as shown in (b), as a processing flow on the NC program side of the machine tool 10, when the processing (ST10=ST1) is started and the interrupt control function is turned on (ST11), a sub-call to be called when an interrupt occurs. Register the program (ST12). The sub-programs include a sudden stop of the machine tool 10 and an evacuation operation of the machining tool machining 1 from the work piece 2 (IF[#103GEGE123.4]GOTO100, which will be illustrated later). Then, when the interrupt signal is received from the external personal computer 8, the subprogram registered in ST12 is executed and controlled to perform a quick stop or a save operation (ST14). When the processing is completed, the interrupt yesterday is turned off (ST15), and the processing is completed (ST16).

Specifically, as a retracting operation of the machining tool 1 from the workpiece 2, the tool is retracted when the temperature reaches 123.4° C., and the change of the CNC variable and the interrupt signal are illustrated in the interrupt control for exchanging the tool. When the CNC variable assigns acceleration [m/s2] to #101, force (torque: rotational acceleration) [rad/s2] to #102, and temperature [°C] to #103 at time t, the threshold value is 120.4°C ( #103 = 123.4). In addition, as the saving operation of the machining tool (IF[#103GE123.4]GOTO100) as a subprogram of the NC program, the 100th line is specified as the saving operation of the machining tool 1. Then, as the processing progresses, for example, the real-time measurement values received by the external personal computer 8 are #101=1.2, #102=234.5, #103=23.4 at time t1, #101=23.4 at time t2, When #102=4567.8, #103=56.7, #101=67.8 at time t3, #102=12345.6, #103=234.5, #103=234.5>123.4 at time t3, that is, the threshold value is exceeded ( For details, reach the threshold at the time between t2 and t3). At this time, if the subprogram IF [#103GEGE123.4] GOTO100 is executed when the threshold value is exceeded, the saving operation and replacement operation of the processing tool 1 are performed.

Next, control for executing subprograms such as tool marks (machining marks) generated on the workpiece 2 and deburring at the moment when it is determined that so-called "chatter" of the machining tool 1 and burrs of the workpiece 2 have occurred. An example is illustrated. An example of the processing flow is shown in FIG. 3, (a) shows an example of the processing flow in the external personal computer 8, and (b) shows an example of the processing flow of the NC program for controlling the operation of the machine tool 10. On the external personal computer side, as shown in (a), when the process (ST20) is started, the external personal computer 8 sends the temperature information from the thermocouple 6 and the acceleration information from the acceleration sensor in the tool holder 3 as in FIG. The stress information is read (ST21). Next, it is determined whether or not the temperature/acceleration/force read in the external personal computer 8 reaches the threshold value (ST22). This threshold value is set in advance with temperature, acceleration, and force that are considered to satisfy the conditions of "chattering" of the processing tool 1 that affects processing accuracy and damage of the processing tool 1 and occurrence of burrs that cannot be overlooked, depending on the processing conditions. deep.

If the temperature, acceleration, or force is above the threshold, it is detected that "chatter" or burrs have occurred, and an interrupt signal is sent to change the NC program to perform the tool mark removal operation or deburring operation of the workpiece 2. (ST23). Then, when the processing is completed and it is not necessary to continue the measurement (ST24), the processing is completed (ST25).

Further, as shown in (b), as the processing flow on the NC program side of the machine tool 10, when the processing (ST30=ST20) is started and the interrupt control function is turned ON as in FIG. 2 (ST31), The subprogram called when an interrupt occurs is registered (ST32). The sub-program here includes a tool mark removing operation and a deburring operation. For example, if it is determined that "chatter" has occurred at an acceleration of 50.0 [m/s2] or more and the deburring subprogram is the 101st line of the NC program, IF[#101 GE 50.0] will be GOTO 101. Then, when the interrupt signal is received from the external personal computer 8, the sub program registered in ST32 is executed, and control is performed so as to perform the "chatter" removing operation and the deburring operation (ST34). When the processing ends, the interrupt yesterday is turned off (ST35), and the processing ends (ST36).

1... Machining tool 2... Workpiece 3... Tool holder 4... Spindle 5... Stage 6... Thermocouple 7... Operation panel 8... External PC (external control means)
9... Warning light

Claims

An external processing system capable of externally changing operation control of a machine tool having a processing tool for processing a work,
A machining tool, a tool holder that grips the machining tool and is connected to a spindle of a machine tool, or a measuring unit that detects a physical change of the machine tool in real time and externally transmits the data.
An operation control means dedicated to the machine tool, which is provided in the machine tool and controls the operation of the machine tool, the machining tool and the tool holder,
An external control means provided outside the machine tool,
The external control means includes receiving means for receiving data from the measuring means by wireless bidirectional communication, and the machine tool and the machining tool by the operation controlling means based on the data from the measuring means received by the receiving means. And an external control means for changing the normal operation control of the external processing system of a machine tool.
The external control means determines whether or not the data from the measuring means is within a predetermined allowable range, and if it is outside the allowable range, operates an interrupt signal for changing the normal operation control by the operation control means. The external processing system for a machine tool according to claim 1, which transmits to the control means.
The operation control means registers another control mode different from normal when changing the normal operation control by the operation control means, and an interrupt signal for changing the normal operation control by the operation control means from the external control means. The external processing system for a machine tool according to claim 2, which executes another registered control mode in place of the normal control mode when the message is received.
The measuring means has a sensor for detecting at least temperature and/or acceleration data in the processing tool or the tool holder, and wirelessly transmits data from the sensor to an external control means.
When the external control means determines that the data from the sensor has exceeded a preset threshold value as an abnormality of the machining tool, it stops the operation of the machining tool and the tool holder, and a warning lamp included in the machine tool. The external processing system for a machine tool according to claim 2 or 3, wherein the normal operation control by the operation control means is changed to turn on.
The measuring means has a tool sensor for detecting at least temperature and/or acceleration data in the processing tool or the tool holder, and wirelessly transmits the data from the tool sensor to an external control means. The machine has a sensor for machine tool that detects data of physical change of each part of the machine tool, and transmits data from the sensor for machine tool to an external control means,
When the external control means determines that the data from the tool sensor and the machine tool sensor is outside the preset allowable range as a machining tool abnormality, the operation control means causes the machine tool and the machine tool to operate. The external processing system for a machine tool according to claim 1, wherein the normal operation control of the processing tool is changed.
The measuring means has at least a sensor for detecting temperature data of the processing tool in the processing tool or the tool holder, and wirelessly transmits temperature data from the sensor to an external control means,
When the external control means determines that the temperature data from the sensor has exceeded a preset threshold value as an abnormality of the processing tool, it stops the operation of the machine tool and/or the processing tool and the tool holder, After the operation is stopped, when it is determined that the temperature data from the sensor is equal to or lower than or lower than the preset temperature value as the threshold value or the temperature for restarting the operation, The external processing system for a machine tool according to claim 2 or 3, wherein the normal operation control by the operation control means is changed so as to restart from the processing when the operation is stopped.