JPH0112625B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention monitors changes in machining conditions that occur particularly in relation to tool wear in a numerically controlled lathe, and corrects the feed rate according to the progress of tool wear. When performing so-called adaptive control that corrects the tool positioning position, when the tool wear progresses and exceeds the control range, the tool movement is stopped and returned to the origin position, and the tool is replaced with a pre-prepared alternative tool and machining is continued. The present invention relates to an automatic tool management method for a numerically controlled lathe that enables unmanned machining by continuing the process without stopping.

Conventionally, various efforts have been made in connection with labor-saving or unmanned machine tools using numerically controlled machine tools. That is, adaptive control machine tools that control cutting conditions by monitoring changes in machining conditions using various sensors or analyzing past data and predicting changes in machining conditions as a function of time, or By measuring the dimensions of the workpiece immediately after machining or at a separate station after machining, errors mainly caused by tool wear are detected, and the automatic measurement correction function automatically corrects the tool positioning position sequentially or for the next machining. Adaptive control machine tools and the like have been developed that can automatically control machining dimensions.
The former aims to improve machining efficiency, and the latter aims to save labor in high-precision machining, and both have achieved their respective objectives. It is one of the means. On the other hand, loading and unloading devices for supplying materials and storing finished products are extremely commonly used, ranging from extremely specialized devices found in small automatic machines to extremely general-purpose devices commonly known as robots. It is being In addition, for the tool change function, a turret turret that can accommodate a large number of tools is prepared, as typified by ATC (automatic tool change device) for machining centers, or as seen in numerically controlled lathes. Various devices have been developed that can perform these functions.

Furthermore, numerical control devices, which are the main control of numerically controlled machine tools, were used as one of the terminal devices of large computers in the past, mainly for the purpose of process control for an entire factory or dozens of machine tools. It is a component of the so-called DNC (group control) system, and the new software fixed type uses a minicomputer or microcomputer at the heart of the numerical control device itself, making it possible to respond to a variety of specifications that vary depending on the individual user. Also, the so-called CNC (Computerized Numerical Control) system, which is said to be a software variable type, has appeared, and it has made a major contribution to more advanced automation, labor saving, and even unmanned processes, and has provided many suggestions for how to proceed in the future. giving.

Now, the various functions mentioned above have functions to issue an alarm or automatically stop when an abnormality or inconvenience occurs, All of these functions basically follow a predetermined program. Our mission is to operate, just as a normal worker would do.
Re-grasp the material and re-measure the material at any time.
Or, if a danger is detected during cutting, the machine is usually not brought to an emergency stop, the tool is returned to its original position, the tool is replaced, and cutting is continued again.

In other words, even if we carefully prepare various setup operations, trial cutting, etc. so that a series of machining operations can be carried out normally, not only dimensional changes mainly due to progress of tool wear, but also increases in cutting force and It is well known that there are temporary phenomena such as changes in the state of chip formation, and if these are left unaddressed, it will lead to unexpected secondary accidents. The more skilled an ordinary worker is, the more accurately he or she can monitor changes in the machining situation mentioned above, and make judgments in response to changes in the machining situation based on his or her various experiences. , the above-mentioned machining operations are interrupted, tools are replaced, measurements are re-loaded, cutting conditions are changed, etc. as needed, and only by doing this can a machined part with the required accuracy be reliably obtained. . Therefore, even if a system is equipped with one or more of the above-mentioned functions, it cannot be said that a higher degree of automation or labor-saving has been achieved, much less that it has become unmanned.

In view of the above-mentioned current situation, the present invention aims to add a new function to organically link various independent technologies and to enable unmanned operation in a numerically controlled lathe.

In other words, for rough cutting tools, the cutting force is monitored and the feed rate is controlled so that the cutting force remains constant to prevent sudden accidents such as tool breakage, and to prevent the feed rate from exceeding the control range. If this occurs, it is assumed that the tool is worn out, and the machine stops feeding, automatically returns to the tool's original origin position, replaces the tool, and continues the machining operation, just as a normal worker would do. For tools, the finished dimensions are automatically measured, and the positioning position of the tool is automatically corrected based on the error, and while the finished dimensions are controlled to be constant, the amount of automatic correction is accumulated, and the positioning position of the tool is automatically corrected based on the error. When the cumulative value reaches a certain value, it is assumed that the finishing tool has worn out, and the tool is automatically replaced as if it were a normal worker to continue machining work, and automatic measurement is also performed. If an abnormality occurs during the process, the measurement is automatically re-measured as a normal worker would do, and when loading the material, check for eccentricity, inclination, size, etc., and check if it is found to be abnormal. In addition, when performing the above-mentioned functions, tools (measuring tools) for determining the quality of cutting phenomena, measurement results, and loading results are provided. (Includes equipment and loading equipment.) Tool management involves preparing a tool management table in which specific data is set, and determining processing contents in response to changes in various machining conditions, mainly using the tool management table as a criterion for judgment. The aim is to provide functions that will enable safer and more precise machining operations to be performed unattended.

DESCRIPTION OF THE PREFERRED EMBODIMENTS An automatic tool management system, which is an embodiment of the method according to the present invention, will be described in detail below with reference to the drawings. FIG. 1 shows the overall configuration of an embodiment of the invention.

The main components shown in this figure are a numerically controlled lathe 100, a flexible loader 141, a conveyor 142, a chip conveyor 144, a numerical controller 146, and an intelligent controller 147. Note that the flexible loader 141, the conveyance device 142, and the chip conveyor 144 are only shown by two-dot chain lines. Next, the constituent elements will be explained in order.

The numerically controlled lathe 100 adopted in this embodiment includes a main spindle 102 rotatably supported by a main spindle box 101,
A gripping tool (hydraulic chuck in this embodiment) 103 for the workpiece (raw material, material being processed, or completed workpiece) attached to the tip of the spindle, a saddle 105 that slides in the Z-axis direction on the bed 104, and a handle on the saddle. The main components are a cross slide 106 that slides in the Z-axis direction, a turret tool rest attached to the tip of the cross slide 106, and a dodecagonal tool rest 107 in this embodiment. Note that the X-axis and Z-axis directions are
Illustrated in the figure. Normal rotation, reverse rotation, stop, and rotation speed of the main shaft 102, as well as opening and closing of the hydraulic chuck 103, 12
The indexing of the corner tool rest 107, etc. is performed by the numerical control device 14.
6 via a mechanical control panel 151, and the amount of movement of the saddle 105 and cross slide 106 is directly controlled by a numerical controller 146.
Furthermore, as a peripheral device of the numerically controlled lathe 100,
A lubricating oil device 111 that lubricates the sliding surfaces of the saddle 105 and the cross slide 106, a hydraulic unit 112 required for opening and closing the hydraulic chuck 103 and indexing the dodecagonal tool rest 107, and a hydraulic unit 112 that is not clearly shown in the figure. However, there is a cutting oil device, etc. required during machining, and the above components are the same as those of a normal numerically controlled lathe.

Next, in order to achieve the object of the present invention, the numerically controlled lathe 100 is equipped with various sensors to monitor changes in machining conditions or the status of each part of the machine, and these will be explained below. do.

First, for the purpose of monitoring the wear of the rough cutting tool,
A principal force component 12 is installed near the dodecagonal tool rest 107 to detect the principal component force of cutting, which has a proportional relationship with the amount of wear on the cutting tool.
1 is installed. Next, in order to monitor the wear of the drill, in order to detect the thrust force which is also proportional to the amount of wear of the drill, the thrust force of the Z-axis feed screw shaft which receives the feed force of the saddle 105 is detected, although it is not clearly shown in the figure. A thrust sensor 122 is installed near the bearing. Note that these principal force sensors 12
The thrust sensor 1 or the thrust sensor 122 is a sensor for not only monitoring tool wear but also for so-called adaptive control that controls the feed rate according to an increase or decrease in the main component force or thrust for the purpose of improving machining efficiency.

In addition, for the purpose of monitoring the wear of the finishing tool,
Specifically, for the purpose of monitoring the wear of the finishing tool in the X-axis direction, the amount of wear of the finishing tool corresponds well to changes in the finished dimensions of the workpiece, and by monitoring the amount of movement of the cross slide 106. saddle 105 to monitor the amount of movement of
An X-axis automatic measurement system is provided, which consists of a digital linear scale, that is, an X-axis scale 123 mounted above, and an X-axis contact sensing sensor 124 attached to one station of the dodecagonal tool rest 107 in the same way as a tool. There is.

Next, the operation of this automatic measurement system will be described. The X-axis contact sensor 1 is directed toward the workpiece 108 that has just been finish-milled and is gripped by the hydraulic chuck 103.
24 is numerically controlled in exactly the same way as the tool to make contact and separation with one point on the diameter of the workpiece 108 to be measured, and then to make contact and separation with another point on the diameter opposite to the X-axis contact sensing sensor 1.
24 from the workpiece 108 for the first time to the second time for the cross slide 106
The actual size of the workpiece 108 can be determined by detecting the amount of movement by the X-axis scale 123 and subtracting the width of the tip of the X-axis contact sensor 124, which has been verified in advance, from the detected amount of movement. It is. The details of this automatic measurement system are described in "Japanese Patent Application No. 147386/1983" by the present applicant.

On the other hand, for the purpose of monitoring the wear amount of the finishing tool in the Z-axis direction, a Z-axis scale 1 is mounted on the bed 104 to monitor the amount of movement of the saddle 105.
25, and a Z-axis contact sensor 126, which is not clearly shown in the figure, is attached to another station of the dodecagonal tool post 107. These X-axis and Z-axis automatic measurement systems not only monitor the wear of the finishing tool for the purpose of automating high-precision machining, but also monitor the dimensions of the workpiece, just like the principal force or thrust sensors mentioned above. This is to perform so-called adaptive control of machining dimensions by knowing the change and automatically correcting the positioning position of the corresponding finishing tool so that the change is minimized.

The four types of sensors described above were prepared mainly to monitor changes in machining conditions caused by tool wear, but in some cases, only one type of sensor may be used, or completely different sensors, For example, it may be based on sensors such as the spindle torque and the vibration amplitude of the tool post.

Next, the following sensors are prepared for the purpose of monitoring changes in machine operating conditions. First, regarding temperature, the main spindle box temperature sensor 131 detects the temperature of the main spindle box 101, which is most suitable for monitoring the temperature rise or thermal displacement of each part of the machine, and the temperature of the hydraulic oil in the hydraulic unit 112 is detected. A hydraulic oil temperature sensor 132 is prepared, and lubricating oil,
To detect the amount of cutting oil and working oil,
A lubricating oil amount sensor 133, a cutting oil amount sensor 134, and a hydraulic oil amount sensor 135 are provided in each tank. Furthermore, regarding the hydraulic oil, a hydraulic oil contamination sensor 136 that detects the degree of contamination and a hydraulic oil pressure sensor 136 are provided. Hydraulic pressure sensor 13 to monitor the drop
7 is prepared. The various sensors mentioned above that monitor changes in machine operating conditions all generate signals (contact signals) when a certain set value is reached, and their purpose is to issue an alarm when each of the above signals is generated. Or it can automatically stop the machine. With the above, we have prepared various sensors that detect changes in machining conditions mainly due to tool wear and changes in the status of each part of the machine, which are required not only for unmanned operation but also for automation and labor-saving machines. .

Now, numerically controlled lathe 10 equipped with various sensors.
0 has been described, however, as other components of the present invention, several kinds of materials or processed products 10
A flexible loader 141 that loads/unloads 8, a transport device 142 that transports the raw material or the processed product 108, and a rigid bucket 143 that stores the raw material or the processed product 108 that is determined to be defective as described later. A chip conveyor 144 or a chip bucket 145 for removing chips is provided. These are necessary to enable unmanned driving, but since they may be general ones, detailed explanations are omitted.

Next, regarding the numerical control device 146, this numerical control device 146 may be one for a normal two-axis numerically controlled lathe, but it exchanges various information with an intelligent control device 147, which will be described later. For this purpose and other reasons, the following functions shall be provided. That is, (146-1): It is possible to memorize the NC program representing the procedures of loading/unloading, measurement, correction, and processing of the material, so-called memory operation is possible, and it starts from any sequence number written in the NC program. Furthermore, the sequence number to be started can be received from outside the numerical control device. (Hereinafter, this function will be referred to as the "sequence number rewriting function.")
(146-2): Commands related to tools on NC programs are usually called T functions or T commands.
It is represented by a 2-digit or 4-digit number representing the Roman letter "T" followed by the tool number for which indexing is desired and the tool position correction register number corresponding to the tool. When this T command is read, this T It is possible to output the contents of the specified T command to the outside of the numerical control device 146 before executing the command, and in response to an external command, the contents of the specified T command can be rewritten in some cases. Therefore, it must be possible to accept rewritten content from outside. In other words, since the contents are rewritten before execution, at the time of execution, the tool specified externally rather than the one specified on the NC program is indexed, and the corresponding tool position correction register is also indexed to the tool position specified externally. A correction operation will be performed according to the contents of the correction register number. (Hereinafter, this function will be referred to as the "tool number rewriting function."
It is called. ) Regarding the T function, if zero is specified as the tool position correction register number,
It means to cancel the tool position correction operation that was performed immediately before, and if zero is specified as the tool number, it means to correct the contents of the next tool position correction register number, and the correction data is stored externally. shall receive more. Regarding this, the former is already commonly practiced, and the latter was detailed in Japanese Patent Application No. 122,227/1983 by the present applicant. (Hereinafter, this function will be referred to as the "tool position correction register correction command.") (146-3): As described later, if loading of one material is defective, reloading is performed, or during automatic measurement. If an abnormal condition occurs for some reason, re-measure the tool, or if an abnormal condition occurs for some reason during cutting, perform an emergency stop of the tool cutting feed and return the tool to its home position and replace it with an alternative tool. If you need to re-cut after
Since the program does not have a built-in process for dealing with such an abnormal state, the command will be received from the outside, but in such a case, the intelligent control device 147, which will be described later, automatically generates the NC program. The numerical control device 146 needs to be able to accept NC programs from the outside. (Hereinafter, this function will be referred to as the "NC program insertion function.") (146-4): As mentioned above, the method of detecting cutting force and performing adaptive control includes a method of controlling depth of cut or controlling feed rate. Although there are various methods, the embodiment of the present invention employs a method of controlling the feed rate so that the cutting force remains constant around a predetermined setting value (referred to as allowable cutting force). Normal numerical control devices have a so-called override function that changes the feed rate specified in the NC program using a manual dial switch, but the present invention also uses a similar method for cutting. It is necessary to be able to receive a command from the outside about what percentage of the specified feed rate the feed rate should be in order to maintain the force at the set value. (Hereinafter, this function will be referred to as the "feed rate correction function.") (146-5): As mentioned above, in order to perform adaptive control regarding machining dimensions, data corresponding to the error value obtained as a result of automatic measurement must be A function is required to receive external information and change the contents of the corresponding tool position correction register number. (Hereinafter, this function will be referred to as the "tool position correction register correction function.") (146-6): While a tool movement command is being executed, the movement is temporarily stopped for some reason, and the execution of the tool movement command is completed. If it is necessary to consider that the tool movement command has been completed, the execution of the tool movement command is completed by clearing the output register that holds the value corresponding to the remaining movement amount for which further pulse distribution is to be performed, and the NC A function is required to wait for a start command to execute the next step of the program. (Hereinafter, this function will be referred to as a "tool movement command interruption processing function.") Next, the intelligent control device 147 will be explained.

The intelligent control device 147 is a main component of the present invention, and in order to organically link the functions of each of the above-mentioned components, it performs situation monitoring, confirmation, judgment, and work that have traditionally been performed by operators of numerically controlled lathes. The aim is to enable unmanned operation of numerically controlled lathes by performing various functions such as interrupting and restoring work.

This intelligent control device 147 uses a microcomputer (hereinafter referred to as CPU) at its heart,
Read-only memory (hereinafter referred to as ROM) that stores intelligent processing programs or groups of automatically generated NC programs for performing various functions described below, and random access memory that temporarily stores various situations when performing various functions. (hereinafter referred to as RAM), non-luminous and rewritable random access memory (hereinafter referred to as RAM) that stores various setting data.
It is called NVRAM. ), a setting display panel 201 for setting and displaying various data, and various interfaces described below for exchanging information with the various constituent elements. In addition, the 8th
The structure of the NC program group stored in the ROM and NVRAM and the set data group is shown in FIG. 9 and FIG.

Next, various interfaces will be explained. (b): Machine status monitoring interface 202
As mentioned above, various sensors 13 are provided in each part of the machine to monitor changes in machine conditions, such as detecting the amount of lubricating oil, detecting the temperature of the main shaft box, and detecting the hydraulic oil pressure.
This is an electronic circuit that receives signals from 1 to 137 and converts them into a form that can be transmitted to the CPU. (B): The automatic measurement system interface 203 transmits information necessary for automatic measurement to the CPU, and receives signals from the X-axis contact sensor 124 and the Z-axis contact sensor 126, The CPU determines that this is the moment when the object to be measured is separated from the workpiece 108.
The CPU also receives information about the actual movement amount of the cross slide 106 and saddle 105 from the X-axis scale 123 and Z-axis scale 125 in the form of a pulse train, and converts it into numerical information while constantly counting it with a counter. It is an electronic circuit mainly consisting of a counter that can be referenced, and also receives information regarding the current position of the tool cutting edge from the numerical control device 146 in the form of a pulse train as described above, and converts it into a form that can be referenced by the CPU. (c): The constant cutting force adaptive control system interface 204 is connected to a position coder 109 that monitors the rotational status of the spindle 102 (for example,
Something that generates a pulse train of 1024 shots. ) is received and counted by a counter, a signal is generated every 1/4 rotation of the spindle, and this signal is used as a cutting force data sampling start command.
It is received by the CPU, or receives analog signals such as voltages outputted from the above-mentioned principal force sensor 121 and thrust force sensor 122 in proportion to the cutting force and thrust force, and is converted into a digital value by an AD converter.
It is an electronic circuit that converts data into a form that can be referenced by the CPU. (d): Numerical controller interface 20
Reference numeral 5 denotes an electronic circuit through which the intelligent control device 147 receives and receives various information described below. That is, information regarding the tool number and tool position correction register number when the numerical control device 146 reads the T command in the NC program, and information regarding the alternative tool number and alternative tool position correction register number when it is necessary to rewrite the tool number. information on sequence numbers for changing the flow of the NC program, information on the NC program automatically generated by the intelligent control device 147, information on the feed rate correction rate, correction data when correcting the tool position correction register. Information related to
(E): The flexible loader/conveyance device system interface 206 transmits commands such as loading, unloading, reloading, etc. from the CPU to the flexible loader 141 and the conveyance device 14.
2 is an electronic circuit that converts the signal into a readable form and converts it into a signal format that allows the CPU to recognize that the commanded operation has been completed.

Next, the setting display panel 201 will be explained. This consists of a push button switch group, a numerical display group, and a display lamp group, and is used to store various data of the tool management table (described later) in NVRAM, display its contents when necessary, and perform various functions. Necessary judgment criteria for making judgments, such as the wear limit of the finishing tool, the allowable range of the material gripping posture, and other related values as described above.
The actual measured values and error values are calculated as a result of automatic measurement and are stored in RAM, and the contents can be displayed as necessary. The actual cutting force and feed rate modification rate are displayed during adaptive control, which will be described later, and changes in the machine operating conditions described above are displayed as a warning. Next, the contents of the intelligent processing program stored in the ROM will be explained by function.

(147-1): Explain the "automatic measurement automatic correction function".

Taking an example of the automatic measurement and automatic correction function in the X-axis direction (in this case, it is related to the measurement of the diameter value of the workpiece 108), on the part to be measured of the workpiece 108 held by the hydraulic chuck 103, NC the X-axis contact sensor 124 from the program origin
The workpiece 108 is moved numerically controlled by the program to cause the first contact and separation, and then this workpiece 108
After contacting and separating the part diametrically opposed to the measurement part for the second time, the program returns to the origin of the program.
The measurement is completed with the above operations, and during this time the following data processing is performed. That is, the amount of movement of the X-axis contact sensor 124 in the X-axis direction during the measurement operation is constantly monitored by the X-axis scale 123, and the amount of movement of the X-axis contact sensor 124 in the By knowing the amount of movement from the moment of separation to the moment of separation for the second time, a value corresponding to the width of the X-axis contact sensor 124 that has been verified in advance is subtracted from this movement amount value (in the case of the inner diameter, add it) ), the actual measured diameter value can be obtained.
Meanwhile, during this measurement operation, the X-axis contact sensor 12 is placed at the position of the dimension to be machined indicated by the current position display of the numerical control device 146, that is, the target value of machining.
4 is positioned, and during the measurement operation, this target value is input from the numerical control device 146 to the intelligent control device 147, and compared with the actual measured diameter value to calculate an error value. Various judgments are made regarding the error value calculated here, as will be described later. If the result is normal, the contents of the tool position correction register corresponding to the finishing tool used to finish the measured part of the workpiece 108 are corrected. It is output to the numerical control device 146 as exponent data. And the actual correction work directs the measurement operation
A tool position correction register correction command is programmed immediately after the NC program, and the numerical control device 1
When the 46 reads this command, the contents of the corresponding correction register are corrected by the internal function of the numerical control device, and the next time an incorrect finishing tool is used, the result of this correction is reflected in the tool positioning position, and the target value is improved. It is possible to obtain processing dimensions close to . The above function is the "automatic measurement automatic correction function".

(147-2): Explain the "remeasurement function".

First, abnormal conditions that may occur during measurement operations will be described below. (1) As tool wear progresses, the finished surface may become rough due to phenomena such as decreased sharpness, and the error value may become extremely large. (2) If the finishing tool is already chipped or damaged just before the part to be measured is finished, the part to be measured will be measured in an unfinished state, and the difference value will be extremely low. Depending on the stroke of the contact sensor, this may even lead to damage to the sensor. (3) Before the measurement operation, the part to be measured is cleaned with cutting oil or specially prepared air blow, but if extremely thin chips are still attached, the error value will be very large (1) The same thing occurs as in case (2), and if large chips are wrapped around the part to be measured, the same thing as in case (2) occurs. (4) If the workpiece has some kind of defect (for example, a cavity in a casting part), the X-axis contact sensor 1 can be detected by the NC program.
24 may not come into contact with the part to be measured even though it is intended to come into contact with the part to be measured. Now, if the above-mentioned abnormality occurs during or before the measurement operation, the error value will generally be a very large value, so it will be necessary to perform the following processing. First, as mentioned in (2), since the sensor must not be destroyed, the X or Z axis scale 123 or 12 must be adjusted from the moment the contact sensor 124 or 126 comes into contact with the object to be measured.
If the amount of movement of the sensor exceeds a preset value (usually about 0.3 to 0.5 mm) related to the stroke of this sensor by counting the pulse train from 5 and reaching the position determined by the NC program. commands the numerical controller 146 to stop feeding, then instructs the numerical controller 146 to consider the execution of the interrupted movement command complete, and then to proceed to the next movement command. command. This allows the touch sensor to continue operating without being destroyed. Note that such a situation will be referred to as a sensor alarm, and the treatment for this will be referred to as "sensor alarm processing."

Next, when the measurement operation is completed, it is first confirmed that "sensor alarm processing" has not occurred during the measurement operation, and then the X-axis contact detection sensor 124 makes contact with and separates from the workpiece 108 to be measured twice. After confirming that the error value is within a preset value, the process moves to the next step, that is, automatic correction operation. However, if even one of the above confirmations is not performed, This will be treated as a measurement error and the measurement will be taken again. To perform re-measurement, the sequence number at the beginning of the NC program that performs the measurement operation is sent to the numerical controller 14.
6, commands to change the flow of the NC program. Numerical control device 146
The sequence number is rewritten using the above-mentioned "sequence number rewriting function" (146-1), and the NC program for the measurement operation is started from the first sequence number specified from the outside.

(147-3): "Defective parts reject function"
I will explain about it. According to the above-mentioned (147-2) "Re-measurement function", if a measurement abnormality is still determined even after re-measurement is performed a pre-specified number of times (usually once or twice), it is considered to be a processing defect.
The flexible loader 141 is instructed to unload without performing the next step in the NC program, and unlike the normal unloading of completed parts, the rigid bucket 143
instruct them to dispose of it. Next, in order to continue the operation, the first sequence number of the NC program is output to the numerical control device 146, thereby starting the loading operation of the next material.

(147-4): Explain the "finishing tool wear monitoring function".

The "automatic measurement automatic correction function" described in (147-1) above successively corrects the contents of the tool position correction register corresponding to the finishing tool used, but each time these corrections are made, The values are accumulated, and if this accumulated value exceeds the value preset in the NVRAM, the finishing tool is considered to have worn out to the extent that it cannot be used again, and the NC program is used to perform the next finishing operation. When a bite is specified, the tool number prepared as an alternative and the corresponding tool position correction register number are used. An instruction is given to the ``tool management function'', which will be described later, so that the ``tool management function'' operates. In addition, (147-1), (147-2), (147-3), (147-4) explained above
In , only the X-axis direction was described, but z
It has exactly the same function in the axial direction.

(147-5): The "constant cutting force adaptive control function" (hereinafter referred to as "RAC function") will be explained. This function is an adaptive control mainly performed on the rough cutting tool, and as the tool wear progresses, the cutting force decreases due to a decrease in sharpness, an increase in the frictional resistance between the flank surface of the tool and the workpiece, etc., and the cutting force increases to an extreme level. In such a case, the tool may be damaged or the overload protection circuit of the spindle motor or feed motor may be activated, causing the machine to stop. On the other hand, it is desirable to control the increase or decrease of the feed rate, which is one of the cutting conditions, so that the cutting force remains at a preset constant value.
As a means for this, the analog signal from the above-mentioned principal force sensor 121 or thrust sensor 122 is AD
Convert it into a digital value using a converter so that the CPU of the intelligent control device 147 can recognize it.
The feed rate correction rate is determined by the following formula while sequentially comparing it with the set allowable cutting force.

Feed speed correction rate (%) = {1 + (allowable cutting force) - (actual cutting force) / (allowable cutting force x K} x 100, where K is the feed speed correction rate gain (usually 4 to 10)
It is.

(147-6): Explain the "rough cutting tool wear monitoring function".

The cutting force increases mainly due to tool wear, but as mentioned in (147-5), the feed rate is controlled to keep the cutting force constant, so the degree of change in the feed rate correction rate is This roughly matches the progress of tool wear. Therefore, by setting the lower limit value of the feed speed correction rate in advance, when the feed speed correction rate falls below this value, it is assumed that the wear of the cutting tool has progressed to the limit, and the numerical control device 146 is activated to interrupt the cutting operation. Give a command to temporarily stop feeding.

(147-7): Explain the "automatic return to origin function".

(147-6) "Rough cutting tool wear monitoring function"
When the tool movement is temporarily stopped due to the function of instructs the user to consider the execution of
Next, the numerical control device 1 executes an NC program (hereinafter referred to as "automatic origin return program") that returns to the program origin specific to the tool 110 being used.
46. As a result, the tool 11
0 means a return to the program origin specific to the tool 110. In connection with this, a method for generating an "automatic origin return program" will be described below. FIG. 2 is a diagram for explaining the path by which the tool 110 returns to the program origin (described later) by this "automatic origin return program". In this figure, the Z axis is defined at the centerline of the workpiece 108 and the
The axis is defined at the rightmost end of the workpiece 108 in the Z-axis direction. Further, the machining origin P is determined at the origin of the X-Z coordinate axis, and the program origins T ₁ , T ₂ , T ₃ are determined at the initial position (movement start position) of each tool 110. Each coordinate system of the program origin is set at the beginning of the NC program (for example, by specifying G50X-Z-CR) using the coordinate system setting function, which is one of the preparation functions of the numerical controller 146.
It is possible to display the current position on the numerical control device 146. From now on, in order to move the tool 110 to the desired position,
It is executed sequentially by specifying the Z coordinate value, but as mentioned above, the tool movement is interrupted during cutting,
To return the tool 110 to the program origin, the numerical controller 146 must be commanded a return path that is not represented in the NC program. One possible method for this would be to memorize all the paths the tool 110 has traveled so far and issue commands in the reverse order, but this is not a preferable method as it would unnecessarily increase the storage capacity. In this system, the numerical controller 146 first stores the coordinate values of the program origins T ₁ , T ₂ , and T ₃ , and at the same time stores the maximum and minimum values of the coordinate values on the path until the tool movement is interrupted. The data is then updated and stored, and the stored results are used to return the tool 110 to the program origins T ₁ , T ₂ , and T ₃ .
That is, to explain the case of outer diameter cutting shown in Fig. 2a as the simplest case, first, the tool 1
10 sends an NC program that moves to point A shown in the figure (its X coordinate value is equal to the X coordinate value of program origin T ₁ ) to the numerical controller 146, and then sends an NC program that moves to the program origin T ₁ . By sending the data to the numerical control device 146, the tool 1
10 is returned to the program origin _T1 . Next, to explain the case of performing internal diameter cutting as shown in Fig. 2b, first, the minimum coordinate value in the X-axis direction (point B)
Then, the NC program moves to point C, whose Z-axis coordinate value is equal to the Z-axis coordinate value of the program origin T ₂ , and thirdly, the NC program moves to the program origin T ₂ . 146, the tool 110 is returned to the program origin _T2 . This allows the tool 110 to return to the program origin without colliding with the workpiece 108. Furthermore, to explain the case of internal diameter cutting shown in FIG.
It is indicated by the digit number, for example M40. ), specify M40 on the NC program when the tool 110 moves to the point D shown in the figure (indicates the place where machining starts with the tool 110), and after recognizing this M40. X of the tool path of
The maximum value of the axis coordinate values is sequentially updated and stored. When returning the tool 110 to the program origin, first, point E whose X coordinate is determined by the stored maximum coordinate value in the X-axis direction.
(shown in Figure 2c), then move the NC program to point F (shown in Figure _2c ) whose Z-axis coordinate value is equal to the program origin T3.
By sending an NC program to the numerical control device 146 to thirdly move the program to the program origin T ₃ , the tool 110 is moved to the program origin T ₃ without colliding with the workpiece 108 as described above.
I'm trying to change it back to . In this way, the tool 110
Hereinafter, the method of determining the return path of the tool 110 by storing the maximum and minimum coordinate values of the movement path will be referred to as the "maximum-minimum value tool return method."

(147-8): Explain the "re-cutting command function".

(147-7) When the tool 110 returns to the program origin by the function of the "automatic origin return function", the next time this tool 110 is specified in the NC program, the tool number prepared as an alternative and the corresponding Instruct the "tool management function" described later to use the tool position correction register number, that is, to operate the "tool number rewrite function" described above, and then perform this rough cutting work.
After outputting the sequence number at the beginning of the NC program to the numerical control device 146, a start command is output. Through the above process, re-cutting using the alternative tool is started.

(147-9): Explain the "material gripping posture check function".

This function is similar to the automatic measurement function described in "Automatic measurement automatic correction function" in (147-1). That is, the flexible loader 14
1, when the material 118 is gripped by the hydraulic chuck 103, the material 118 may be gripped eccentrically with respect to the spindle center line or tilted due to chips attached to the hydraulic chuck 103. The degree of
This function checks whether the value exceeds the allowable value set in advance in NVRAM. To perform this check, use the X or Z axis contact sensor 124 or 126 used in the "automatic measurement automatic correction function" in (147-1).
In the case of automatic measurement, the dimensions of the finished workpiece 108 were the problem, but here the gripped material 1
18 is located at the expected coordinate value (target value) with respect to the machining origin P in the X-Z coordinate system. The operation is exactly the same as in the case of automatic measurement, and to explain the X-axis direction with reference to FIG. At the moment when the material 118 separates from the material 118, the numerical control device 146 activates the contact sensing sensor 124.
Obtain information about the current location of. On the other hand, the first
The value at the time of separation (X coordinate value of point G shown in Figure 3) is PX12, the value at the time of second separation (X coordinate value of point H shown in Figure 3) is PX2, | | PX1 ｜−
|PX2|| is the amount of eccentricity. Then, this amount of eccentricity is compared with a preset tolerance value, and if it is within the tolerance value, the material 118 is attached to the hydraulic chuck 10.
3, it is determined that the grip is normal and there is no eccentricity. Next, it is checked whether the size of the material 118 itself is within an allowable range. This check calculates the error value for the specified dimensions of the material 118 using the calculation formula ||PX1 (or PX2)|-S-TX|, and determines the size of the material 118 (diameter size in this case) based on the calculation result. It is. Note that S in this equation is the X-axis contact sensor 1
This value corresponds to the width of the tip which has been verified in advance. Now, next, the fourth
This will be explained using figures. First, Z-axis contact sensor 1
26 from the program origin T ₅ to the target value TZ (shown in FIG. 4), then returned toward the program origin T ₅ to the extent that it does not hit the material 118, and then to point J (shown in FIG. 4). ), and then
Contact and separate from point K (shown in Figure 4). Then, if the current position in the Z-axis direction obtained during the first separation is PX1, and the position in the Z-axis direction obtained during the second separation is PZ2, the calculation formula |PZ1−PZ2|
The amount of inclination of the material 118 with respect to the center line of rotation can be obtained by . Then, this amount of inclination is compared with a preset allowable value, and if this amount of inclination is within the above-mentioned allowable value, it is determined that the material 118 is normally grasped by the hydraulic chuck 103 and is not tilted. . Next, check whether the length of the material itself is within the allowable range. This check is
This is performed using the fact that the calculation formula |TZ-PZ1 (or PZ2)| indicates the error value of the material 118 with respect to a preset length.

(147-10): Explain the "reloading function".

(147-9) "Material gripping posture check function"
If even one item exceeds the allowable value, the intelligent control device 147 automatically generates an NC program and instructs the following operations to be performed. That is, the material 118 is unloaded, and the material 118 once placed on the conveyance device 142 is loaded again. Next, the numerical controller 146 sends out the first sequence number of the NC program that performs the "material gripping posture check function".
This causes the workpiece gripping posture check to be performed again.

(147-11): Explain the "defective material reject function".

The above-mentioned "reloading function"
If the material gripping posture check still exceeds the allowable value even after reloading the NVRAM the number of times specified in advance, the material 118 is considered defective and the material is transferred to the flexible loader 141 without performing the next step in the NC program. 118, and also instructs to dump into the reject bucket 143. Then the numerical controller 14 is activated to continue the operation.
Sends the first sequence number of the NC program to 6. This allows operation to continue with the loading of the next material 118.

(147-12): Explain the "automatic stop function".

If the above-mentioned "defective material reject function" works continuously for more than the set number of times, or (147-
4) "Finishing tool wear monitoring function" or (147-8) "Re-cutting command function", when commanding the "tool number rewriting function" (146-2) to operate, the substitute If the tool has been used, stop all operations.

(147-13): Explain the "tool management function".

In order to conveniently implement the functions (147-1) to (147-12) described above, a tool management table shown in FIG. 5 is prepared in the NVRAM and contains information necessary for the tool 110 to be used. Set in advance. The structure of the tool management table shown in the figure has columns 1 to 12, and 12 items of information can be set for each column. Furthermore, each row corresponds to a variety of tools 110. For example, to explain the information that should be set in the case of the rough cutting tool shown in the second line of Figure 5a, the first and second items are the tool number specified on the NC program and the corresponding tool position correction. is a register number, and the third and fourth items are the tool number that should be substituted when the tool bit with the tool number specified in the first item is considered to be worn out, and the corresponding tool position correction register number, The fifth item is whether constant cutting force adaptive control is used for the tool specified in the second line (in this case, it is set to 3) or whether automatic measurement and automatic correction function is used. (In this case, it is set to 2.) Or, the set tool number indicates that it is the X or Z-axis contact sensor 124, 126 (in this case, it is set to 1), or any of the above is not applicable (in this case, it is set to 0), that is, the tool 1 is neither the contact sensing sensor 124 or 126 nor is it subject to adaptive control or automatic measurement automatic correction.
This shows whether the value is 10 or not. The sixth item is called an alternative flag, and when it is "0", it indicates that the tool 110 specified on the NC tape should be used, and when it is "1", an alternative tool is used. It indicates what should be done. The substitute flag is changed when the tool 110 in use is considered to have worn out, and if it has already been changed to 1 at that time, this indicates that the substitute tool has been used. As mentioned above, processing such as automatically stopping the machine will be performed. The seventh item is cutting tool 11
When the tool 110 is deemed to have worn out, as described above, the feed of the tool 110 is temporarily stopped, and then an NC program that returns to the program origin is automatically generated.
This item specifies the type of NC program that will be automatically generated at that time. The eighth item is the upper limit value of the feed rate correction rate when the feed rate is controlled to keep the cutting force constant, and the ninth item is the lower limit value. The 10th item indicates the allowable cutting force, and under adaptive control, cutting is constantly performed with this cutting force. The 11th item is the start sequence number of the cutting program to be executed by the tool 110 set in this line in the NC program when a recutting command is issued by the recutting command function described above. The 12th item is for accumulating the actual cutting time of the rough cutting tool shown in the second line and storing the results. As mentioned above, it is considered to be worn out (147-6)
Activate the "rough cutting tool wear monitoring function" or simply issue an alarm. The fourth line of the table shown in FIG.
The 9th item is left blank, the 10th item indicates the allowable value of the tool position correction register correction amount, and the 11th item is not the first sequence number of the cutting program using the finishing tool shown in this line, but the finishing tool with this finishing tool. The 12th item is the first sequence number of the NC program that automatically measures the part that has been changed.The 12th item is the one that accumulates the amount of correction in the tool position correction register and stores the result.This result is referenced by the finishing tool wear monitoring function. be done. It goes without saying that the cumulative result of the amount of correction in the tool position correction register and the cumulative result of the cutting time described above are set to 0 when switching to an alternative tool.

The configuration of the tool management table shown in Figure 5a described above is based on the assumption that there are two tools to be used and one alternative tool for each. It can be changed depending on the target workpiece 108 (for example, when there are few types of tools used and several or more alternative tools are required), and for example, a different configuration may be used. The tool management table will be explained with reference to FIG. 5b. For convenience of explanation, the number of rows and items in the tool management table are 12 columns and 12 items, as in the above case. and,
In the case of the tool management table shown in Figure 5a, the alternative tool number and tool position correction register number were set in the third and fourth items of the same tool management table, but in the case of this Figure 5b, the tool management table The idea is to change the content and perform each action in accordance with the content. Specifically, everything is the same as in the case of FIG. 5a above, except that an alternative line number is set in the third item of each line, and the fourth item is left blank. Now, after reading the T command on the NC tape, the tool management table is scanned and the procedure for determining this tool management table is the same as in the previous case, and then the alternative flag in the 6th item of the tool management table is If the value is 0, execution of the T command is executed without any change. Also, in the case of 1, the third
The line number set in the item is referred to, and that line is regarded as a second tool management table.
The sixth item of the second tool management table is referred to. If this referenced result is 0, it is sent to the tool number rewriting function of the numerical controller 146 as an alternative tool number and an alternative tool position correction register number based on the data set in the first and second items, respectively. If it is 1, refer to the third item of the second corresponding tool management table, determine the third tool management table in the same way as in the above case, and perform the same processing depending on the contents. Let's do it. Furthermore, in the above process, if the third term is set to 0, this indicates that no more alternative tools are prepared. By employing a tool management table with such a configuration, it is possible to prepare several or more alternative tools.

In this way, the necessary information for each tool is set in the tool management table, and while referring to this information, various situations can be monitored, judged, and changed as shown in the flowchart in Figure 7, which will be described later. This function is called a "tool management function."

(147-14): Explain "each information setting and display function".

This function sets and displays various information on the tool management table, various constants such as the equivalent diameter of the X-axis contact sensor 121 and the sensitivity of the principal force sensor 121, and also displays the feed correction rate and cutting force. This is a function that displays changes in machine operating conditions as described above.

Above, we have described various functions that should replace the functions conventionally performed by operators when performing unmanned operation. Numerical control machine tool 100, numerical control device 14 as the center
6. Furthermore, it operates organically while exchanging information with the flexible loader 141 and the like. The operation will be explained in detail below.

As an example, a case where several types of workpieces 108 are processed unmanned will be described. Figure 6 shows the structure of the NC program.
The program is divided into a main NC program and a sub NC program group. These NC programs are stored in a memory dedicated to NC programs in the numerical control device 146, and, as described above, can be executed from any sequence number. And each sub-NC program is 1
It is for machining one type of workpiece 108, and is called from the main NC program by the sequence number attached to the beginning of the workpiece. In the main NC program, the sub NC program is specified and the sub
Specify how many times (corresponding to the number of workpieces) to run the NC program. specified sub
When the NC program completes the specified number of executions, the main NC program moves to the next step. In this way, several types of NC programs are prepared for unmanned machining of the workpiece 108, but this can be done by using the "memory operation function" which is a function of the numerical control device 146 mentioned above. can.

Next, the configuration of the sub NC program and its sub
How the intelligent control device 147 monitors various situations during execution of the NC program and how it responds to changes in the situation will be explained with reference to the flowchart shown in FIG. A sub-NC program is an NC program that expresses the procedure of loading one type of workpiece, machining it, and unloading it after machining is completed, and is divided into six groups depending on the operation content. It is divided. Further, a sequence number (N101 to N106) is attached to the beginning of each group by a numerical value following the Roman letter "N". The first group (N101) transports the material 118 to the conveying device 1.
42 to the hydraulic chuck 103, the second group N102 is a material loading program for grasping the material 1 in the hydraulic chuck 103.
This is a material gripping posture check program that checks 18 gripping postures, and is the third group (N103).
is a rough cutting program that performs rough cutting, and the fourth
The group (N104) is a finishing cutting program that performs finishing cutting, the fifth group (N105) is an automatic measurement automatic correction program, and the sixth group (N106) is a finishing cutting program that performs finishing cutting.The sixth group (N106) is a finishing cutting program that performs finishing cutting. 108 from the hydraulic chuck 103 to the transport device 142. Next, before establishing the behavior of each group,
The T command, which is expressed by a four-digit numerical value following the Roman letter "T", will be explained. The first two digits following this Roman letter "T" indicate the tool number, and the next two digits indicate the corresponding tool position correction register number. When the numerical control device 146 reads this T command, the intelligent control device 147 first uses the specified tool position correction register number as a key or the tool number as a key and selects the second item or the first item in the tool management table. Scans the items and selects the row corresponding to the specified tool. For the sake of explanation, this selected row will be referred to as a corresponding tool management table. Next, refer to the alternative flag in the 6th item of the corresponding tool management table, and if it is "0", no change is made and T is
If the command is executed as instructed, and if it is "1", an instruction is issued to the tool number rewriting function of the numerical control device 146 that indicates the need for rewriting, and at the same time, the third item of the corresponding tool management table is replaced. Tool number and 4th
Sends the alternative tool position correction register number for the item. This activates the tool number rewriting function,
The T command will be replaced and executed.

Next, the operation of each group of the sub-NC program will be explained.

When the material gripping posture check program of the second group (N102) is executed, the sensor alarm signal is constantly monitored as described above, and when a sensor alarm signal is generated, the aforementioned sensor alarm processing is performed and the operation is performed. moves on to processing the next block without stopping. When the execution of this material gripping posture check program is completed, the above-mentioned "material gripping posture check function" (147-9) is executed based on the data obtained during execution.
operates to check whether the material gripping posture is normal or abnormal. If this check is determined to be normal, it will move on to the next rough cutting program, but if it is determined to be abnormal, the number of times preset by the "reloading function" mentioned above (147-10) will be changed. Reloading will take place within. That is, the material 118 held by the hydraulic chuck 103 is once placed on the conveying device 142 and then held by the hydraulic chuck 103 again. Then, referring to item 11 of the corresponding tool management table, the first sequence number "N102" of the material gripping posture check program is sent to the numerical control device 146 and the sub
Execution of the NC program starts again with the material gripping posture check program. In addition, if an abnormality is still determined even after reloading the preset number of times, if the number of times the defective material reject operation has been performed so far is within the preset number, then The "defective material reject function" of (147-11) operates, and the material 118 is dumped into the reject bucket 143, and the sub-NC
The starting sequence number "N101" of the program is sent to the numerical control device 146, and the sub-NC program is executed again from the beginning. Furthermore, if the number of defective material reject operations exceeds a preset number of times, the above-mentioned "automatic stop function" (147-12) is activated and all operations are interrupted.

Now, if the material gripping posture is normal, the transition will be made to the third group (N103), which is the rough cutting program, but while the rough cutting program is being executed, the above-mentioned "RAC function" (147-5) is constantly activated. It's working. That is, tool 1 used for rough cutting
The feed rate is controlled so that rough cutting is performed with the allowable cutting force set in the 10th item of the corresponding tool management table corresponding to No. 10. At the same time, the above-mentioned "rough cutting tool wear monitoring function" (147-6)
is in operation, and the feed rate correction rate is constantly compared with the lower limit value of the feed rate correction rate set in the ninth item of the corresponding tool management table. Then, as the tool wear progresses, when the feed rate correction rate falls below the lower limit value, the tool movement is temporarily stopped, and then the automatic origin return function described in (147-7) is activated,
The rough cutting tool 110 will interrupt rough cutting and return to the program origin. Next, the substitute flag in the sixth item of the corresponding tool management table is referred to, and if the substitute flag is "0", it indicates that the substitute tool has not been used yet, and the above-mentioned (147-8) is performed. "Re-cutting command function" is activated. That is, the alternative flag is set to "1" and the sequence number (N103 in this case) set in the 11th item of the corresponding tool management table is sent to the numerical control device 146. This allows the sub
Execution of the NC program will be restarted again from the beginning of the rough cutting program (N103). As described above, when executing the T command during the rough cutting program, since the alternative flag is set to "1", an alternative tool and tool position correction register are selected. Furthermore, if the alternative flag is already set to "1" at the stage of executing the "re-cutting command function" in (147-8), this indicates that the alternative tool has already been used, and this indicates that the alternative tool has already been used. The "automatic stop function" of (147-112) is activated and all operations are interrupted.

Now, when the rough cutting program is executed normally, the finishing cutting program of the fourth group (N104) is executed next. The progress of wear of the finishing tool 110 is checked by the next automatic measurement and automatic correction program. That is, when the automatic measurement automatic measurement automatic correction program of the second group (N105) is executed, the above-mentioned "automatic measurement automatic correction function" of (147-1) measures the part of the finished workpiece 108 to be measured. Actual values, error values, etc. have been calculated. When the tool position correction register correction command, which is usually issued last in the automatic measurement automatic correction program, is executed, if the results of various checks are normal, the corresponding tool position correction register is changed based on the calculated error value. The contents of will be corrected. Further, if the check results indicate that there is an abnormality and re-measurement is permitted, the re-measurement function (147-2) described above is operated. This re-measurement operation is performed as follows. That is, by sending to the numerical controller 146 the first sequence number (N105 in this case) of the automatic measurement automatic correction program set in the 11th item of the tool management table corresponding to the tool that finished the part where the measurement was performed. , the sub-NC program will be executed again from the beginning of the automatic measurement and automatic correction program. Note that the number of times re-measurement is permitted is preset depending on how many times the re-measurement operation has been performed consecutively before. Now, if it is determined that there is an abnormality even after re-measuring the preset number of times,
This workpiece 108 is considered to be defective, and the above-mentioned "defective parts reject function" (147-3) is activated, and the workpiece is dumped into the reject bucket 143. Then, the sub NC program is executed again starting from the first sequence number (N101). When the operation of the "defective parts reject function" (147-3) also exceeds a preset number of times, the "automatic stop function" (147-12) described above is activated. On the other hand, (147−
If the tool position correction register is corrected normally as a result of the "automatic measurement automatic correction function" in 1),
The above-mentioned "finishing tool wear monitoring function" (147-4) is activated. When the wear progresses and is determined to be at the limit due to the function (147-4), if the alternative flag in the 6th item of the corresponding tool management table is "0", it means that the alternative tool has not been used yet. Therefore, after setting the alternative flag to “1”, the next step, that is, the sub
We move on to the unloading program, which is the sixth group (N106) of the NC program. This result is then applied to the corresponding finishing tool 110.
When executing the T command in a finishing cutting program that uses If it has already become "1", this indicates that the substitute tool has been used, and the "automatic stop function" mentioned above (147-12) is activated and all operations are interrupted.

Now, although the automatic tool management system targeted at numerically controlled lathes has been described above, it is easy to apply it to other numerically controlled machine tools, and it can be easily assumed that it will be highly effective.

As explained above, according to the present invention, the sub
While the NC program is being executed, changes in machining conditions mainly caused by tool wear are monitored, and cutting conditions are controlled to actively deal with changes in machining conditions obtained as a result of this monitoring. Cutting is performed with a constant cutting force to prevent sudden phenomena such as tool breakage, while also ensuring that the finished dimensions of the workpiece are uniform and allowing high-precision machining to continue over a long period of time. It ensures that work continues safely by checking whether loading and measurement operations are abnormal or normal due to the influence of chips, and automatically selects a replacement tool when tool wear reaches its limit. By using it, the machining operation can be continued, and when loading or measurement is not carried out normally, the operation can be continued by reloading or remeasuring, or when the material or the finished product is defective. Even in such cases, the work can be continued by discarding them, so that unmanned operation of numerically controlled lathes or other numerically controlled machine tools can be carried out more reliably.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the configuration of an embodiment of the present invention, FIG. 2 is a diagram for explaining the "automatic origin return function" of the embodiment shown in FIG. 1, and FIG.
4 are diagrams for explaining the "material gripping posture check function" of the embodiment shown in FIG.
FIG. 5 shows the tool management table of the embodiment shown in FIG. 1, and FIG. 6 shows the NC of the embodiment shown in FIG.
FIG. 7 is a flowchart showing the operation of the embodiment shown in FIG. 1, and FIGS. 8 and 9 are diagrams showing the structure of the program.
FIG. 3 is a diagram showing the contents of ROM and NVRAM. 100... Numerical control lathe, 108... Workpiece, 11
0... Tool, 118... Material, 121... Principal force sensor, 122... Thrust sensor, 124... X-axis contact sensor, 126... Z-axis contact sensor, 147...
Intelligent control device.

Claims (1)

[Scope of Claims] 1. In a numerically controlled lathe having a plurality of cutting force sensors and a plurality of contact sensing sensors, (a) the cutting force sensor performs cutting while monitoring changes in machining conditions due to tool wear; The tool feed rate is controlled so that the force is constant, and when the tool feed rate becomes less than a predetermined value, the tool is automatically replaced, and (b) the contact sensing sensor performs machining. Measure the dimensions of the completed object, correct the positioning of the tool so that the measurement results remain constant, and if the cumulative value of correction exceeds a predetermined value due to tool wear, replace the tool. (c) Accumulating the actual cutting time of the tool during rough machining, and when this cumulative value exceeds a predetermined set time, it is assumed that the tool is worn and the tool is automatically replaced; (d) The loading state of the material is measured by the contact sensor, and if a predetermined limit value of the material loading state is exceeded, loading is performed again, and if it is determined that there is an abnormality as a result, the material is removed. Considered defective and abandoned.
Loading a new material; (e) Measuring the finished state of the processed product using the contact sensing sensor; if the finished state exceeds a predetermined limit value, the measurement is repeated, and as a result, further abnormalities may occur. If it is determined that the machined product is defective, the machined product is considered to be defective and is discarded, and then a new material is loaded, and the above process enables unmanned processing for a long time. automatic tool management method in 2. A tool management function that performs tool management while referring to a tool management table in which tool-specific constants are set; an automatic measurement automatic correction function commanded by this tool management function; a remeasurement function; a machined defective part reject function; Includes finishing tool wear monitoring function, constant cutting force adaptive control function, rough cutting tool wear monitoring function, automatic return to origin function, recutting command function, material gripping posture check function, reloading function, defective material reject function and automatic stop function. An automatic tool management method in a numerically controlled lathe according to claim 1, characterized in that said control is performed. 3. When executing a command related to a tool while the NC program of the numerically controlled lathe is being executed, by referring to the alternative flag in the tool management table immediately before execution, the NC program can be executed as is, or the NC program can be executed as is. Determine whether to run after rewriting, and if the above
When the NC program is executed after being rewritten, the NC program is executed after being rewritten based on the corresponding alternative tool number and alternative tool position correction register number in the numerically controlled lathe. An automatic tool management method in a numerically controlled lathe according to claim 1 or 2, characterized in that: 4. If a measurement error is determined during the execution of the NC program of the numerically controlled lathe, remeasurement can be performed by changing the execution order of the NC program according to the sequence number listed in the tool management table. An automatic tool management method in a numerically controlled lathe according to claim 1 or 2, characterized in that: 5. During the execution of the NC program of the numerically controlled lathe, if a measurement error is determined and re-measurement is not permitted, the machined object is deemed to be defective and is discarded, and then the first sequence number of the sub-NC program is changed to the numerically controlled lathe. 5. An automatic tool management method in a numerically controlled lathe according to claim 1 or 4, wherein the sub-NC program is input to the lathe and the numerically controlled lathe is operated in accordance with the sub-NC program. 6 Regarding the tool position correction register correction command of the NC program of the numerically controlled lathe, the contents of the specified tool position correction register are corrected, and this correction value is accumulated in the tool management table, and this cumulative value is set in advance. Claims 1 or 2, characterized in that when the accumulated allowable value is exceeded, the alternative flag in the tool management table is rewritten and the accumulated value is cleared. Alternatively, the automatic tool management method in a numerically controlled lathe according to item 3. 7 Regarding the automatic origin return function, if it is determined by the rough cutting tool wear monitoring function that the tool wear has reached the limit while the tool is cutting, the numerically controlled lathe is temporarily stopped and the tool movement path is adjusted in advance. A numerically controlled lathe according to claim 1 or 2, characterized in that the maximum coordinate value and the minimum coordinate value are stored, and the tool is returned to the program origin based on the stored results. Automatic tool management method. 8 If the rough cutting tool wear monitoring function determines that the tool wear has reached the limit and the numerically controlled lathe is temporarily stopped, the command being executed is considered to have been completed and the next step in the NC program is started. 8. An automatic tool management method in a numerically controlled lathe according to claim 1, 2, or 7, characterized in that the operation of the numerically controlled lathe is moved. 9 Regarding the re-cutting function, when the tool returns to the programmed origin by the automatic origin return function,
The alternative flag in the tool management table is referred to, and if the alternative flag instructs execution as it is, the alternative flag is rewritten so as to be executed after rewriting it, while the alternative flag is set in the tool management table. A sequence number is sent to the numerically controlled lathe, and the NC program is executed from the step to which the sequence number is attached. Alternatively, the automatic tool management method in a numerically controlled lathe according to item 7. 10 Regarding the material gripping posture check function,
When the material is loaded, the contact sensing sensor is brought into contact with and separated from the workpiece to check the loading state of the workpiece, and calculate the amount of eccentricity or inclination of the workpiece with respect to the main axis center line. An automatic tool management method in a numerically controlled lathe according to claim 1 or 2, characterized in that the diameter and length of the material are also calculated. 11 Regarding the reloading function, the limit value regarding the loading state of the workpiece, that is,
Limit eccentricity, limit inclination, diameter limit, and length limit are set in advance, and when the check result by the material gripping posture check function exceeds even one of the limit values, By determining that the loading state of the material is abnormal, unloading the material, loading the same material again, and sending the sequence number set in the tool management table to the numerically controlled lathe. 11. The automatic tool management method in a numerically controlled lathe according to claim 1, 2, or 10, characterized in that the loading state of the reloaded material is checked again. 12 Regarding the defective material reject function, if the loading state is still determined to be abnormal even after performing reloading by the reloading function a preset number of times, the material is deemed to be defective and is discarded; Built-in sub
Claim 1 or 2 or 1 characterized in that the first sequence number of the NC program is sent to the numerical control device.
An automatic tool management method in a numerically controlled lathe according to item 1.