JPS5810438A - Tool chucking control device of machine tool equipped with atc - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an automatic tool attachment/detachment device for an ATC-equipped machine tool, and is a tool chucking control device that has an additional function of detecting a tool chucking error and re-chucking the tool.

In the conventional automatic tool attachment/detachment device, a motor attached to the rear end of a drawing bolt (hereinafter referred to as the drawbar) inserted into the main shaft rotates the I-bar in the forward and reverse directions, and the male screw at the tip of the drawbar, which is seen through the tapered hole of the main shaft, is attached to the tool shank. The tool is screwed into the female screw, and the tool is fastened to the main shaft taper hole. By the way, it is known that for some reason the male screw of the drawbar is not screwed into the female screw of the tool shank, and the tool is not fastened to the spindle approximately once every several hundred times. In such cases, the tool shank may fall due to incomplete tightening, and the function of the automatic tool changer cannot be fully utilized. As a countermeasure to this problem, various methods have been implemented, such as examining the shape of the tip of the male screw and the accuracy of the screw, but none of them are perfect.

The present invention was made in view of the above situation, and
The tool shank fastening state is detected from the motor load current, that is, if the motor angular charge current becomes excessive after a certain period of time, it is detected that the tool shank is completely fastened, and the chucking operation is terminated. If it is a normal operating current, it is detected as a poor tool shank connection, the drawbar motor is reversed, the male screw at the end of the drawbar is separated from the female screw on the tool shank, and the motor is rotated forward again to perform a chucking operation to screw both screws together. By repeating this process, we succeeded in eliminating chucking errors.

The apparatus of the present invention will be explained below with reference to embodiments shown in the drawings. First, the machine tool shown in Figure 1 is a vertical milling machine F equipped with an automatic tool changer, and the main parts are Pace 1, Column 21, Knee 3. Saddle 4. Table 5° Spindle head 6. It consists of a main shaft 7 and a main shaft driving motor MO. TM is a tool storage magazine that stores a large number of tools T, and TA is a tool exchange arm that exchanges the tool T1 chucked on the spindle 7 with the tool T in the tool storage magazine TM. 10 is an automatic tool attachment/detachment device placed on the top of the spindle head 6, and as shown in FIG. 2, a drawbar 8 inserted into the spindle 7.
The tool shank T1 is attached to and detached from the tapered hole 7a of the main shaft 7 by driving the drawbar e motor M1 in the forward and reverse directions to rotate the drawbar 8 in the forward and reverse directions. That is, the male thread 8a at the tip of the drawbar 8 seen in the taper hole a of the main shaft is the female thread 11a at the top of the taper 11 of the tool shank T1, which is gripped by the tool changing arm TA and inserted into the taper hole 7a. 3rd to
As shown in the figure (when the arm TA rises, it comes into contact with the arm TA. Subsequently, the drawbar 8 is rotated in the normal direction by the forward rotation drive of the drawbar motor M1, and the male screw 8a is screwed into the female screw 11a, as shown in FIG. The taper 11 of the tool T1 is pulled into the spindle taper hole 7a and fastened.However, the male screw 8. cannot be screwed into the female screw 11a and continues to idle, and when the predetermined chucking time elapses, the state shown in FIG. 3 occurs. If the drawbar 8 stops rotating and the tool change arm TA then releases its grip on the tool shank T1, an accident will occur where the tool shank T1 falls.

The gist of the present invention is to repeat the chucking operation up to three times if a chucking error occurs;
The outline will be explained using a p-chart (shown in the figure). First, a chucking command is issued when the tool shank Tl is inserted into the tapered hole 7a as shown in FIG.
The chucking operation begins when the chucking is rotated in the normal direction, and whether or not the chucking is successful is detected by the current sensor of the drawbar motor after a predetermined period of time. If chucking is successful (YES), the miss counter is reset and the re-chucking mode is cleared.If chucking is unsuccessful (No), the timer setting time (delay time) 5 set It is detected that the subsequent motor current is a normal value □, and the mistake counter counts +1, and the change arm lowers and the drawbar reverses (0.5 to 1.0
sgc), the change arm rises, and the chucking operation is repeated again to rotate the motor M1 in the normal direction. Successful chucking (YES) + Unsuccessful chucking (No>) is detected by the counter as in the previous case, and if unsuccessful, the miss counter becomes +2 and the third chucking operation is started, but the miss counter When counted to +3, an alarm is displayed and the chucking operation is stopped.Of course, if the chucking is successful (YES), the tool change is completed and the tool change is completed.
, the main shaft rotates and moves on to the next process.

An apparatus for carrying out the chucking operation shown in the above flowchart is shown in FIG. 6.7. First, the re-chucking circuit CE, which is the core of the present invention, includes a timer To, a counter cm, and three sets of OR elements 01-o3, which are connected to an NC device, a drawbar motor control circuit MC, and a change arm control circuit AC. It is organically connected and exhibits re-chunking function. That is, the input end (・a) of the timer To in the re-chucking circuit CE and the two OR elements 02
+03 is connected to receive the chucking command from the NC device, and the timer TQ reaches the time-up end (cJ) t after 55ac from the input of the chucking command.
This output becomes a release command and energizes the reverse link-DR of the drawbar 1 motor control circuit MC.
The change arm control circuit AC is controlled as a change arm lowering command. Also, the reset end of timer TQ (c)
The reset signal to is inputted as a meshing completion signal output from the current sensor C8 of the drawbar motor control circuit MC, and this meshing completion signal is outputted from timer To's time up 4 to 5.
It is output earlier than the GC to prevent release commands and change arm lowering signals from being sent. Furthermore, the mesh completion signal is input to the OR element O1, the machining continuation signal to the NC device, and the OR element 0 connected to the reset terminal (/~) of the counter cm.
3 and reset the counter Co. Input to the input terminal (A) of the counter cm is performed by a time-up signal from the timer TQ terminal (+=). The ON operation signal of limit switch LS1 is input to OR element 02 and sends a change arm raise command to change arm control circuit AC, and also sends a chucking command to drawbar motor control circuit MC to activate forward rotation relay DF of motor M1. It is energized to perform a chucking operation. At the same time as this chucking operation, the reset timer To receives a signal from the limit switch LSI and is restarted (time measurement). And current sensor C8
If a time-up signal is sent three times to timer TO or counter co without a mesh completion signal being sent from counter Co, the count-up signal is sent from counter Co to its output terminal (
b) and lights up the alarm lamp AL, while sending a motor stop command to the drawbar motor control circuit MC and also transmitting a stop command to the NC device.

In addition, the forward/reverse relays DF and DR of the drawbar motor M1
The connection of the 'P current sensor C8 is as shown in FIG. That is, the forward rotation relay DF of the motor M1 has its contacts /-... interposed in the electric circuit a+b*e, and the reverse rotation relay DR has its contacts connected to the wires α and C by interchanging them (interphase switching). A branch line a'l' bZ 6' is interposed therebetween. In addition, the overload current of motor M1 is picked up by current center CCK located close to electric line a = c, and the current value is detected by current sensor C8 and set to the set value (■3).
When it exceeds this, a meshing completion signal is output.

The chucking control device of the present invention is constructed as described above, and its operation will be explained below. Now, as shown in FIG. 1.2, for tool exchange, a new tool shank T1 is gripped by the tool exchange arm TA, and the taper hole 7 of the main shaft 7. It becomes a position where it can be inserted into the body.

At this time, a chucking command is output from the NC device to the re-chucking circuit CE. Now, when the counter CO is reset to zero, the timer To set to s3ge starts counting down, and the re-checking circuit C
From E, a chucking command is sent to the drawbar motor control circuit MC, which activates the forward rotation relay DF to start the motor M1 in forward rotation, and a change arm raising command is sent to the change arm control circuit AC, causing the arm TA to rotate. Rise. Then,
As shown in FIG. 3, the female screw 11 at the top of the taper of the tool shank Tl. comes into contact with the male end screw 8a of the drawbar 8 which rotates normally, and here both 8a.

The screwing of 11a begins. As a result, as shown in Figure 4, t
Drawbar male screw 8. is female screw 1 of tool shank T1
1, the tool shank T1 will taper into the hole 7.
The rotation of the motor M1 is restricted while an overload current is flowing through the motor M1. Figure 8 shows the transient phenomenon from the start of the drawbar motor M1 to the overload current state. In other words, when the drawbar motor M1 starts, a large starting current rI
t, 11 flows and becomes a steady current I2 during the chucking operation, and from the time when the tool is fastened (tl), the rotation of the motor Ml is stopped and an overload current ■o begins to flow, and after the time t2, the current sensor Set current value I set with C8
Over 3. The engagement completion signal transmitted from the current sensor C8 earlier than t3=s gag resets the timer To and also resets the counter CO. In addition, the engagement completion signal becomes a motor stop command, deenergizes the forward rotation relay DF of the drawbar motor control circuit MC, and stops the motor M1, and is sent to the NC device as a machining continuation signal. is opened and the main shaft 71 is driven.

The above chucking operation was performed when the tool shank Tl was smoothly fastened to the main shaft 7, but below the tool shank Tl
The effect when l is not fastened to the main shaft will be explained. That is, if the steady current (2) during the chucking operation is maintained even after the time t2 (approximately 35 gc) at which the engagement completion signal is transmitted, the tool shank T1 is integrated with the drawbar 8. Since it is rotating, timer To outputs a time-up signal at the set time t3 (sBaC).

The above signal is input to the drive p-bar motor control circuit MC.
The J-input command energizes the reverse relay DR and motor M
At the same time as the drawbar 8 is reversed for t4-0.5 to 15sc, the time amplifier signal becomes a change arm lowering signal and activates the change arm control circuit AC.
The tool changing arm TA holding the tool shank T1 is lowered. It is also input to the counter Co and +1 is added thereto.

As a result, the female screw 11a of the tool shank T1, which has been incompletely engaged with the male screw 8a at the tip of the drawbar 8, is separated from the tip of the drawbar, and soon the tool change arm turns on the IJ9 switch LS1. Motor M1 during the above period
The change in load current is as shown by the chain line in FIG. That is, the motor M1 is reversed by the energization of the reversing relay DR, and the starting current flows in the opposite direction as shown by the chain line, then becomes a steady current, and after t4 = 0.5 to 1.05 gC, the limit switch LSI is turned on. In operation, the chucking command deenergizes the reversing relay DR of the drawbar motor control circuit MC, and the motor current becomes zero for a short time t5.Limit switch L
When SI turns on, the draw motor control circuit MC energizes the forward rotation relay DF to start the motor Ml in the forward rotation.
At the same time as the timer TQ starts operating (counting down), the change arm control circuit AC raises the tool change arm TA.

With this, the second re-chucking operation begins, and as shown in FIG. 3, the female screw 11. comes into contact with the tip male screw 8a of the drawbar 8 which rotates normally, and both 11cL
, 8. The meshing begins. Here, as shown in Fig. 4, when the screwing of both 11a and 18α is completed and an overload current flows to the motor M1, a meshing completion signal is output from the current sensor when the set value 3 determined by the current sensor C8 is exceeded. This becomes a stop command for motor M1, and motor M1
While stopping the timer To and +1 while it is operating (counting down)
Reset each counter Co calculated in N
It is sent to the C device as a processing continuation signal. The current change from the start of the motor M1 to the overload current IQ follows a curve exactly the same as the previous time, as shown on the right side of FIG.

However, when the set time t3 (5 sec. At the same time, the operating arm TA of the change arm control circuit AC is lowered, and the counter CQ is added to +2. Female screw 11a of tool shank T1
is separated, and when the arm TA falls, the limit switch Ls
1 performs the second ON operation.

In response to this signal, the timer To is started and the countdown begins, and the change arm TA is driven upward, and the motor control circuit MC rotates the motor M1 in the forward direction. With the above operation, 3
The chucking action to fasten the tool shank T1 to the taper hole of the spindle starts, and this time too, if the E current sensor cs does not output the engagement completion signal within the time amplifier time of the timer TQ (5!1 gc), a time up signal is generated. +
A count-up signal is output from the counter Co which is added to 3. Alarm lamp A is activated by this count amplifier signal.
At the same time as turning on L, a motor stop command is sent to the drawbar motor control circuit to stop the motor M1, and a stop command is sent to the NC device, and the change 7-mu TA tapers the gripped tool shank T1 as shown in Fig. 3. It is stopped in the state where it is inserted into the hole 76.

As described above, if the tool shank T1 is not fully engaged with the drawbar, the chucking operation is performed several times (in the above example, 3 times).
The chucking operation is repeated for a number of times, but the number of times may be set as appropriate), and the chucking operation is performed again to achieve complete engagement.If complete engagement is not achieved even after applying the chucking operation a predetermined number of times, the chucking and NC device operations are performed. Stop.

According to the present invention, a current sensor is provided in the drawbar motor control circuit for forwarding and reversing the drawbar to detect an overload current when the tool shank is fastened and output an engagement completion signal, and a time-up signal is provided in the re-chucking circuit. A timer for outputting and a counter for setting the number of chucking are provided, and when the current sensor outputs an engagement completion signal within the time-up time set by the timer, the timer and counter are reset and a processing continuation signal is sent to the NC device. When the meshing completion signal is not output, the counter is incremented by the time-up output, the timer is set, and a chucking command is sent to the drawbar motor control circuit and the change arm control circuit, and the meshing completion signal is output or the set number of counters is set. Since the structure is configured so that the chucking operation is repeated until the end, the male screw of the drawbar is not screwed into the female screw of the tool shank for some reason, and the tool is not fastened to the spindle, which happens once every few hundred times. It is possible to eliminate the chucking errors caused by the shank, thereby preventing accidents of the tool shank from falling due to incomplete fastening of the tool shank, and having the effect of fully utilizing the functions of the ATC device of the machine tool. In addition, wear and tear on the male screw at the end of the rover and the female screw on the tool shank can be detected at an early stage.

[Brief explanation of drawings]

Fig. 1 is a perspective view of a vertical milling machine with ATC equipped with the device of the present invention, Fig. 2 is a partially cutaway sectional view of the spindle head, and Figs. 3 and 4 are states in which the tool shank is fastened to the main spindle taper hole. 5 is a flowchart showing the operation of the device of the present invention, FIG. 6 is a block diagram of the control system centered on the re-chucking circuit of the present invention, and FIG. 7 is a wiring diagram of the drawbar motor. , FIG. 8 is a time chart diagram. 6...Spindle head, 7...Spindle, 7a/Φ/tapered hole,
8... Drawbar, 8a... Male screw, 10... Automatic tool attachment/removal device, Tl--tool shank, 11a... Female screw, Ml... F R-motor, MC... Drawbar skewer motor control circuit, TA/0 tool change arm, AC
...Change arm control circuit, C8...Current sensor, CCQ...Current center, NC...NC
Device, CE...e re-chucking circuit, To...timer, CO...counter, 01~o3-1I/OR element, DF...forward rotation relay, DR@0 reverse rotation relay, LSl
...Limit switch, AL...Alarm lamp,
Il@...Starting current, I2...Operating current (chucking current), I3...Set value current, IQeΦ/Overload current, C3...Time-up time. HB No. 3 BiiJ Male 2M Procedural Amendment (Spontaneous) October 7, 1981 Commissioner of the Patent Office Shima 1) Haruki Tono 1, Indication of Case Patent Application No. 1065 (18) of 1988
No. 2. Name of the invention Tool chucking control device for machine tool with ATC 3. Person making the amendment Relationship to the case 4. Applicant 4. Date of amendment order Voluntary amendment 5. Subject of amendment Correction of specification and drawings Clarification □Details 1. Title of the invention: Tool chucking control device for a machine tool with ATC 2. Claims: The drawbar motor control '11 circuit for forwarding and reversing the drawbar is designed to detect overload current when the tool shank is fastened. The re-chucking circuit is equipped with a timer that outputs a chucking time-up signal and a re-chucking setting device that repeats a predetermined chucking operation. When the current setting/switching completion signal is output within the time, the re-chucking setting device is reset and the NC
Send a machining control signal to the device, and when the mesh completion signal is not output, send a re-chucking command to the drawbar motor control circuit and change arm control circuit at the timer's time up %l to output the mesh completion signal or set re-chucking. A tool chanking control device for a machine tool with an ATC, characterized in that the chucking operation is repeated up to a set number of times determined by the machine. :3. Detailed Description of the Invention The present invention relates to an automatic tool attachment/detachment device in a machine tool, and is a tool chucking control device that has an additional function of detecting tool chuck/shank mistakes and re-chucking the tool. . The conventional automatic tool attachment/detachment device consists of a motor (r=t) attached to the rear end of a 1-rowing bolt (hereinafter referred to as a drawbar) inserted through the main shaft. From here, rotate the row forward and reverse 1゛, and the male screw at the tip of the draw or tip that looks into the spindle tip hole is the female screw e of the tool shank.
This is screwed together, and the T-tool body/L-da is fastened to the main shaft taper hole. By the way, once every few hundred times, the female screw of the dop-ka is not screwed together with the female screw of the t-ka/ri for some reason, and the J-gai hole ends up being fastened to the main 1111.
It is known that this occurs at a certain rate, and in such cases, the tool holder may fall due to incomplete tightening of the tool shank, and the function of the automatic tool changer cannot be fully utilized. do not have. As a countermeasure to this problem, various methods have been implemented, such as examining the shape of the tip of the male screw and the accuracy of the screw, but none of them are perfect. As mentioned above, the present invention has a detection function for chuck/king mistakes with the tool spindle that occur approximately once every several hundred times, and performs a re-chucking operation when a chucking mistake occurs. If the chunking error is still not resolved even after repeated chucking operations, the chucking operation is performed again and again, and if a predetermined number of times or a predetermined time is exceeded, chucking is not possible and the chucking operation is stopped. The purpose is to The present invention, as the best technical means to achieve the above object, detects the engagement state of the tool shank from the load current of the drawbar and motor. In other words, if the motor load current becomes excessive after a certain period of time, the tool shank is completely engaged. If this is the case, the chunking operation is terminated, and if the current is normal, it is detected as a defective connection of the worker's wayank, and the drawbar motor is reversed to separate the male screw at the tip of the drawbar from the female screw on the tool shank. By rotating the Tanabata in the normal direction again and repeating the chucking action of screwing both screws together, we succeeded in eliminating the richacing mistake. Then, set the number of repetitions for Chaining A/Nking Minu using the Bricent force unc, or operate it only within the set time of the timer.1. When these re-chucking setting devices operate, chucking is disabled and the chucking operation is stopped, thereby preventing the fall of the N'P tool holder with a male screw at the end of the drawbar, and enabling early detection of defective tools. The apparatus of the present invention will be explained below with reference to embodiments shown in the drawings. First, the machine tool shown in Figure 1 is a vertical milling machine F equipped with an automatic tool changer, and the main parts are the base 11 frame 2I.
Knee 3 + saddle 41 table 5° spindle head 6. It consists of a main shaft 7 and a main shaft driving motor MQ. And TM
TA is a storage magazine for storing a large number of tool holders T, and TA is a tool exchange arm for exchanging the tool holder TI chucked by the spindle 7t with the tool holder T in the tool storage magazine 'rM. 10 is m of spindle head 6
As shown in Fig. 2, the automatic tool attachment/detachment device is connected to the top end of the drawbar 8 inserted into the main shaft 7, and the draws 7 and 8 are driven by the forward and reverse rotation of the drawbar motor M1.
The tool holder T1 is attached to and detached from the tapered hole 7a of the spindle 7 by rotating the tool holder T1 in the forward and reverse directions. That is, the tip male screw 8a of the drawbar 8, which is seen in the taper hole a of the main shaft, is connected to the third female screw 11a at the top of the shank 11 of the tool holder Tl, which is held by the tool change arm TA and inserted into the taper hole 7a. As shown in the figure (-meme TA rises, it comes into contact with the motor M. Following this, the lever ψ motor M
1, the drawbar 8 rotates in the normal direction, the male screw 8a screws into the female screw 11a, and as shown in FIG. When the male screw 8a cannot be screwed into the female screw 11a and continues to idle and the predetermined chucking time has elapsed, the rotation of the tool 8 stops and the tool changing arm TA If the grip on the holder T1 is released, an accident of falling of the tool holder T1 will occur.The embodiment of the present invention is designed to repeat the chucking operation when a chucking error occurs, and the flow yard shown in FIG. The outline will be explained. First, the chucking command is as shown in Figure 3 (tool shank 1
1 is inserted into the taper hole 7a, it is emitted, and the drawbar
The chucking operation starts with the normal rotation of the motor Ml, and the chucking operation is successful, but the drawbar does not move after a predetermined time.
Detected by the motor's current sensor. If chucking is successful (YES), the re-chucking setting device is reset and the re-chucking mode is cleared. On the other hand, chucking failure (N
o) is the timer setting time (delay time) 5 sec
It is detected that the subsequent motor current is a normal value, and it is counted as +1 for re-chunking, and the change arm is lowered, the drawbar is reversed (0.5 to 1.o sec), the change arm is moved up, and then the change arm is moved up again. The chucking operation is repeated to rotate the motor M1 in the normal direction. Successful chucking (
YF, S), failure (No) is detected by the current sensor as in the previous time, and if it is unsuccessful, the re-chucking becomes +2 and the third chucking operation is started, but the re-chucking becomes +3. When counted, an alarm is displayed and the chucking operation is stopped. Of course, if the chucking is successful (YES '), the tool change is completed, the spindle rotates, and the process moves on to the next process. If a time-limited timer is used in the re-chucking setting device, an alarm will be displayed when the timer exceeds the set time and the chucking operation will be stopped. The first step to execute the chucking operation in the above flowchart.
The embodiment apparatus is as shown in Fig. 6.7. First, the re-chucking circuit CE, which is the core of the present invention, uses a timer To.
and a power printer CO and three sets of OR elements 01 to 03, which are an NC device, a drawbar motor control circuit MC,
It is organically connected to the change arm control circuit AC to perform the re-chucking function. That is, the input terminal (A) of the timer To in the re-chucking circuit CE and the two OR elements o2.03 are connected so that the chucking command from the NC device is sent, and the timer TQ receives the chucking command. 58#C after input, it is output to the time-up end (b), and this becomes a release command to energize the reverse relay DR of the drawbar motor control circuit MC, and also serves as a change arm lowering command to the change arm control circuit AC.
control. Further, the reset signal to the reset end (...) of the timer To is input as the meshing completion signal j output from the current sensor C8 of the drawbar motor control circuit MC, and this meshing completion signal is applied to the time amplifier time 5 of the timer To.
Output earlier than 0C, and do not transmit release command or change arm lowering signal. Furthermore, the meshing completion signal is input to the OR element 01, the processing continuation signal k to the NC device, and the reset terminal (c) of the counter cO, which is a re-chucking setting device, is connected to the L OR element 03, and the signal is input to the L OR element 03. Reset. The input to the input terminal (A) of the counter CQ above is the timer TQ.
This is done by using the time-up signal tα from the time-up end (b) of . The ON operation signal of the limit switch LSI is input to the OR element 02 and sends a change arm upper row command to the change arm control circuit AC.At the same time, a chucking command is sent to the driver motor control circuit MC to control the motor. The forward rotation relay 7DF of M1 is energized to perform the chucking operation. At the same time as this chucking operation, the set timer TQ receives a signal from the limit switch LFil and is restarted (time measurement). Then, without the engagement completion signal j being issued from the current sensor C8, a time-up signal t is sent from the timer To to the counter cm three times.
When a is sent in, a count-up signal Cα is output from the output terminal (b) of the counter Co and the alarm lamp AL is lit, while the drawbar motor control circuit MC)
A stop command is sent to the NC device as well as a command to stop the motor. In addition, the forward/reverse relays DF and DR of the drawbar motor Ml
The connection of P current sensor C8 is as shown in Fig. 7. That is, the forward rotation relay DF of the motor M1 has its contacts f connected to the electric circuits α, b, #, and the reverse rotation relay DR has its contacts r connected to the electric circuits (two wires α and C of 1" e). The branch line α/
, b' and c'. Moreover, the overload current of the motor Ml is picked up by the current converter CC located close to the electric line α-C, and the current sensor C8
When the current value is detected by and exceeds the set value (Step 3), a meshing completion signal j is output. Next, a second embodiment of the preset counter c (1), which is a re-chucking setting device, is changed to a time-limited timer TLl. Input the chucking command of the NC device to a) and use this command to set the timer TL.
Start the energization (time measurement) of l, input the engagement completion signal j from the drawbar 0 motor control circuit MC to the reset end (c), and energize the timer TL1 (time measurement) with this command.
Configure it to stop. Then, the time limit timer TL1 is activated from this energization to the output terminal (I:
The delay time (setting time) until outputting the time amplifier signal tb in I) is set to the time required to repeat the re-chucking operation, for example, three times (each time is 6 to 7 seconds, so 21 seconds + c, which is three times this time). Ru. The above time limit timer TL
The output end (+-) of the output terminal 1 is connected to the alarm lamp AL as an OR element 01 for a motor stop command and a stop command for the NC device. Therefore, after the chucking operation of the tool holder T1 is started, the timer TL1 outputs a time-up signal t.
If the re-chucking operation is repeated even after the set time (21gmc) until outputting b, timer TL1
is not reset by the engagement completion signal j and outputs a time-up signal tb. Now, the time-up signal tb
turns on the alarm lamp AL and inputs it as a motor stop command to the drawbar motor control circuit MC to stop the motor M1, and also sends it to the NC device as a stop command to completely stop the re-chucking operation. Of course, when the timer TL1, which is activated within the set time of the timer TL1, receives the meshing completion signal j from the drawbar motor control circuit MC, it is reset. Now, the timer TL1 stops energizing, and the time-up signal tb is not output to the output terminal (b), and the operation of the NC device continues. As mentioned above, when the time limit timer TL1 is used as a rechucking setting device, the setting of the number of times of rechucking of the tool holder T1 is determined by a multiple of the rechucking time, but this is essentially different from the direct setting of the number of times using the preset counter CO. It can be said that they perform the same operation. In the second embodiment, the other circuit configurations are the same as those in the first embodiment shown in FIG. 6, so the same reference numerals are used and the explanation of the configuration is omitted. The chucking control device of the present invention is constructed as described above, and its operation will be explained below using a first embodiment using a preset counter Co. Now, as shown in FIG. 1.2, the new tool shank 11 held by the tool changing arm TA is in a position to be inserted into the tapered hole 7a of the spindle 7 for tool changing. At this time, a chucking command is output from the NC device to the re-chucking circuit CE. With this, the counter co is reset to zero, and the timer To set in 5811c starts counting down, and the re-chucking circuit CF
The chucking command is sent to the drawbar motor control circuit M.
C and energizes forward relay DF '111--E--
The arm TA is started to rotate in the normal direction, and a chain arm raising command is sent to the change arm control circuit AC to raise the arm TA. As shown in FIG. 3, the female screw 11a at the top of the taper of the tool boulder T1 comes into contact with the male screw 8a at the tip of the draw rod 8, which rotates in the normal direction, and now both 8a. Screwing of 11a begins. As a result, as shown in FIG.
When the tool shank 11 is fully screwed into the taper hole 7a, the tool shank 11 is fastened and fitted into the tapered hole 7a, and the rotation of the motor Ml is restricted while an overload current is flowing therethrough. FIG. 9 shows a transient phenomenon from the start of the drawbar motor M1 to the overload current state. That is, when the motor M1 is started, a large starting current 11 flows and becomes a steady current (2) during the chucking operation, and from the time when the tool is fastened (tl), the rotation of the motor M1 is stopped and the overload current IQ begins to flow. , t2, the current exceeds the set current value I3 set by the current sensor cs. earlier than t3-5 sec (the meshing completion signal j sent from the current sensor cs resets the timer TQ, and also resets the cursor c. MC forward rotation relay DF
When the motor M1 is deenergized and the motor M1 is stopped, a processing continuation signal is sent to the KNC device, which opens the gripping claw of the arm and drives the main shaft 7. - The above chucking operation was performed when the tool shank 11 was smoothly fastened to the main shaft 7, but below, the operation when the tool shank 11 is not fastened to the main shaft 7 will be explained. That is, the steady current (2) during the chucking operation reaches the time t2 (when the engagement completion signal is transmitted).
If it is maintained even after approximately 3sgc), the tool hoarder Tl is rotating integrally with the drawbar 8, so the ant timer To is set at the set time t3c 5 set).
A time-up signal tα is outputted. '' signal becomes a release command to the drawbar motor control circuit MC, energizes the reversing relay DR, and reverses the motor Ml (drawbar 8) for t4-0.5 to 1 sac, and at the same time, the time-up signal is activated. becomes a change arm lowering signal, which activates the change arm control circuit AC to lower the tool change arm TA holding the tool holder T1. It is also input to the counter Co and +1 is added thereto. Now drawbar 8
The tool shank 11 is incompletely engaged with the tip male screw 8a.
The female screw 11a is separated from the tip of the drawbar, and eventually the tool exchange arm turns on the limit switch LSI. The change in the load current of the motor M1 during the above period is as shown by the chain line in FIG. That is. The motor M1 rotates in reverse by energizing the reversing relay DR, and its starting current flows in the opposite direction as shown by the chain line, and then becomes a steady current, t4 = 0.5 to 1. After Osge, the chucking command deenergizes the reversing relay DR of the drawbar motor control circuit MC by turning on the limit switch LS1, and the motor current becomes zero for a short time t5. limit switch LSI
The drawbar motor control circuit MC energizes the forward rotation relay DF to start the motor M1 in the forward rotation by the ON operation of -Raise muTA. With this, the second re-chucking operation begins, and as shown in FIG. 3, the female screw 11a at the top of the taper rotates in the forward direction, and the male screw 8. and both 11a, 8.
The meshing begins. Here, as shown in Figure 4, both tta
, S, is completed and an overload current flows through the motor M1, the current sensor outputs a mesh completion signal j when the set value ■3 determined by the current sensor C8 is exceeded, and this causes the motor M1 to stop. As a command, the motor Ml is stopped, and the timer TO which is in operation (counting down) and the counter CO which is counted to +1 are reset, and the signals are sent to the NC device as a processing continuation signal. The current change from the starting force of the motor M1 and the overload current (i) until it becomes zero becomes a curve exactly the same as the previous time, as shown on the right side of FIG. However, when the set time 13 (55ec) of timer To passes with both 11 (z+8a) still incompletely screwed together,
The time amplifier signal tα is output to energize the reversing relay DR of the drawbar 0 motor control circuit MC to reverse the motor M1, while the change arm control circuit AC lowers the arm TA and changes the counter c (1 to +2). Now, the female screw 1 of the tool shank 11 that is incompletely screwed or cannot be screwed and remains in contact with the male screw 8a at the end of the drawbar.
1a is separated, and the limit switch LSI turns on for the second time when arm TA falls. This signal resets the timer To and starts counting down, further driving the change arm TA upward, and causing the motor control circuit MC to rotate the motor M1 forward. With the above operation, 3
The chucking action to fasten the tool shank 11 to the taper hole of the spindle has started, and now [1, within the time-up time of timer To (5sacy-current sensor C
If the engagement completion signal j is not outputted from the counter 8, a count-up signal Cα is outputted from the counter Co which is incremented by +3 by the time-up signal tα. This count-up signal turns on the alarm lamp AL, sends a motor stop command to the drawbar motor control circuit to stop motor M1, and sends a stop command to the NC device, and the change 7-m TA is gripped as shown in Figure 3. It is stopped with the tool holder Tl held inserted into the tapered hole 7a. As described above, if the tool shank 11 is not fully engaged with the drawbar, the chucking operation is performed several times (in the above embodiment, three times).
The chucking operation is repeated for a number of times, but the number of times may be set as appropriate), and the chucking operation is performed again to achieve complete engagement.When complete engagement is not achieved even after applying the chucking operation a predetermined number of times, the chucking and NC device are activated. stop. When using this invention, the drawbar motor control circuit that rotates the drawbar in forward and reverse directions should be
A current sensor is provided to detect an overload current of 2 and output a meshing completion signal, and a re-chucking circuit 2 is provided with a timer that outputs a chucking time-up signal and a re-chucking setting device that repeats a predetermined chucking operation. When the meshing completion signal is output from the current sensor within the time-up time set by the timer, the recharging 7 key/gating setting device is reset and the NC device is sent a machining continuation signal, and if the meshing completion signal is not output, the time amplifier This configuration sends a re-chucking command to the drawbar motor control circuit and change arm control circuit using a signal, and repeats the chucking operation until a meshing completion signal is output or until the set number of times is determined by the re-chucking setting device. This eliminates the chucking error that occurred once every few hundred times, where the male screw of the tool was not screwed into the female screw of the tool shank for some reason, and the tool was not fastened to the spindle. , prevents tool shank falling accidents due to incomplete tightening of the tool shank, and improves the AT of machine tools.
This has the effect of fully demonstrating the functions of the C device. Also, the drawbar tip J [wear and tear on the female screw of the child and tool shank can be detected early. 4. Brief explanation of the drawings Figure 1 is a perspective view of a vertical milling machine with ATC equipped with the device of the present invention, Figure 2 is a partially cutaway sectional view of the spindle head, and Figures 3 and 4 are views of the spindle taper. Fastening state of tool shank to hole′
FIG. 5 is a sectional view showing the operation of the device of the present invention) p-
Chart diagram, FIG. 6 is a block diagram showing the first embodiment of the control device system centered on the re-chucking circuit of the present invention, FIG. 7 is a wiring diagram of the drawbar motor, and FIG. 8 is a diagram showing the second embodiment. The block diagram shown in FIG. 9 is a time chart diagram. 6...Spindle head, 7...Spindle, 7a-@Taber hole,
8... Drawbar, 8a... Male screw, 10-- Automatic tool attachment/detachment device, T1... Tool holder, 11... Tool shank, 11a... Female screw, Ml... Drawbar motor, MC...Fist drawbar motor control circuit, TA...
・Tool change arm, AC...Change arm control circuit, C8...Current sensor, CCe...Current converter, NC---NC device, CE--Re-chucking circuit, To...Timer, Co...■ Counter, TLl・
・・Time-limited timer, 01~o3---OR element, DF---
-Forward rotation L/-, DR"" Reverse relay, LSlo...limit switch, AL@@-alarm lamp, T1/e
・Starting current, T2... Operating current (chucking current)
, T3...Set value current, IOe...Overload current, C3
... Time up time, ... Meshing completion signal, &
11 @ 11 Processing continuation signal, tar th... time amplifier signal, Cα... count up signal, procedural amendment (voluntary) December 2, 1980 Commissioner of the Japan Patent Office Shima 1) Haruki Tono 2, Invention Machine tool tool chucking control device 3 with name A'l'C;
Relationship with the case of the person making the amendment Patent applicant address 4888-4 Takatsuka, Kamimura, Hamana-gun, Shizuoka Prefecture Date of amendment order Voluntary amendment 5, subject of amendment Column 6 of “Detailed Description of the Invention” of the amendment Contents We are amending a portion of the voluntary F-based procedural amendments submitted on October 7, 1981 + the attached amended statement as below. Insert the sentence "Only to start motor M1" and delete the sentence "Emitted," in the second line of the same page. (2) The sentence "following" on page 6, line 13 of the specification is corrected as follows. "When the change arm TA descends to the bending point of the horizontal turning section, a change command is issued by actuation of the switch." (3) "rNC device" on page 7, line 14 of the specification Insert the text "Limit switch LS1 that detects when the change arm TA comes to the horizontal rotation part (b-c)". (4) Insert the sentence ``at the time of tool replacement earlier than ``in front of ``rNC device'' on page 12, line 5 of the specification. (5) Insert the following sentence between the 12th and 13th lines of page 17 of the specification. [In addition, in the above two embodiments, the connection is made so that the chucking command is sent from the NC device to the re-chucking circuit CE at the time of tool exchange, but this connection may be omitted. In this case, the first chucking command to the re-chucking circuit CE is the horizontal turning section (b -
c) Mitsutwitch LSI that turns ON when raised to
This is a chunking command from . J

Claims (1)

[Claims] The drawbar motor control circuit that rotates the drawbar in the forward and reverse directions is equipped with a current sensor that detects overload current when the tool shank is fastened and outputs an engagement completion signal, and the re-chucking circuit has a timer that outputs a time-up signal and a chucking number. When the current sensor outputs a meshing completion signal within the time-up time set by the timer, the timer and counter are reset and a processing continuation signal is sent to the NC device, and when the meshing completion signal is not output. The time amplifier output adds color/color, resets the timer, and sends a chucking command again to the drawbar motor control circuit and change arm control circuit until the meshing completion signal is output or the chucking operation continues until the number of times set in the counter is reached. A tool chucking control device for a machine tool with an ATC, characterized in that it is configured to repeat.