JPH03190642A - Automatic tool change operating method and automatic tool change device - Google Patents

Abstract

PURPOSE:To enhance the accuracy of turning-stop position of a tool change arm by controlling the tool clamping time in synchronism with operation of the tool change arm by a clamp timer operating from a specified angle in the course of the turning operation of the tool change arm. CONSTITUTION:A detection dog D1 for stopping a tool change arm 2 and a detection dog D2 for a tool clamp are provided on an input shaft 9, and both the dogs are detected by a proximity sensor S. With the detecting timing of the dogs D1, D2 by the sensor S, detection of the dog D1 is performed at the time when the arm 2 is returned to a stand-by position, and the dog D2 is detected to the time of reversing of the arm. Further, a tool K2 is timely unclamped by an unclamp timer T1 operating simultaneously with the start of the arm 2, while it is timely clamped by operating a clamp timer T2 from a specific turning angle of the arm 2 by sensor-detection of the detection dog D2.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention not only positively synchronizes the tool unclamping and clamping operations with the rotational movement of the tool changing arm by electrical means, but also enables the rotation stop position of the tool changing arm to be precisely synchronized. It is highly accurate.

[Prior Art and Problems J The turning mechanism of the tool changing arm in a conventional automatic tool changer is disclosed in Japanese Utility Model Application No. 63-1-13530 and Japanese Utility Model Application No. 64-1999.
As shown in 1830, a front cam and a roller gear cam are provided on one cam disk, and the turning movement and forward/backward movement of the tool changing arm are completely synchronized.

Furthermore, the operation of the Kohai exchange arm and the tool unclamp operation are completely synchronized mechanically.
3. '3945 and JP-A-63-529, in which the spindle head is unclamped by a cam mechanism when it reaches the origin position at the rising end.
No. 42 and others are provided.

However, in an automatic tool changer that uses these mechanisms, if the operation of the tool change arm and the tool unclamp operation are completely synchronized mechanically, the tool unclamp mechanism can be incorporated into the drive mechanism of the tool change arm. This method is difficult to adopt because it has to be built-in, making the mechanism complicated and large, making it difficult to attach it to the machine body, and increasing costs. In addition, (2) In the method in which the cam mechanism unclamps when the spindle head reaches the origin position of the rising end by moving the spindle head, there is no need to incorporate the tool unclamp mechanism into the drive mechanism of the tool change arm, but the spindle The internal clamping device requires a temporary clamping device for the tool holder.As a result, the clamping device becomes more complicated and the main shaft becomes larger.
In addition, this method is difficult to adopt because it increases costs.

As shown in Japanese Patent Application Laid-Open No. 63-57135, the synchronous operation of the drive mechanism of the tool change arm and the tool unclamp mechanism is performed by electrical means. In this method, the solenoid valve is activated to unclamp the clamp device using a switch, and an unstable time is required from the dog detection to the solenoid valve operation. Furthermore, even if a motor with a brake is used, the rotation stop position of the tool change arm is easily distorted, making it difficult to use in an automatic tool changer that operates at high speed.

"Problems and Means to be Solved" The present invention has been made in view of the above-mentioned problems, and in addition to positively synchronizing the tool unclamping and clamping operations with the rotational movement of the tool change arm and the timer function of the electric means, The purpose of the present invention is to provide a method and apparatus for highly accurate rotation stop position of a tool changing arm.

Specific implementation method and device (1) An unclamp timer that operates at the same time as the start of the tool change arm unclamps the tool, while a clamp timer that operates from a specific angle while the tool change arm is turning is used to unclamp the tool. This is an automatic tool change operation method that controls the clamp timing in synchronization with the operation of the tool change arm.

(2) The rotating shaft of the motor drive system that operates the tool changing arm is equipped with a detection dog for stopping the tool changing arm and a detection dog for the tool clamp, and an unclamp timer that operates simultaneously with the activation of the tool changing arm 11. While the tool is unclamped by the sensor detected by the detection dog, a clamp timer that operates from a specific rotation angle of the tool exchange arm is activated, and the tool clamp timing is controlled in synchronization with the operation of the tool exchange arm. It is something.

(3)] - The motor with a brake that operates the tool exchange arm has a braking force value of at least 20% of this torque value.
The drive system is equipped with a detection dog for stopping the tool change arm and a detection dog for the tool clamp on the rotation axis of the drive system, and an unclamp timer that operates at the same time as the start of the tool change arm to stop the tool. While unclamping, the sensor detection of the detection dog activates a clamp timer that operates from a specific rotation angle of the tool exchange arm, and controls the tool clamp timing in synchronization with the operation of the tool exchange arm. Upon detection, the automatic tool changer suddenly stops the tool change arm using the brake-equipped motor that increases the braking force.

As described above, according to the present invention, the automatic tool changing operation is smooth, and the tool unclamping and clamping operations are performed stably, and high-speed operation is possible without the need for temporary clamping.

"Example" Fig. 1 is a block diagram disclosing the automatic tool changer of the present invention, Fig. 2 is a time chart showing the relationship between ATC operation and clamping, Fig. 3 is a braking characteristic diagram of a motor with a brake,
FIG. 4.5 is a flowchart showing the relationship between ATC operation and clamping.

In FIG. 1, an ATC device 100 for a spindle head 1 and a tool change arm 2 of a machining center, an unclamping device 1 for a spindle 3, and a PC control unit P that controls their operation will be described.

First, the ATC device 100 has a 1° force 11 type drive unit 10 consisting of a cam type drive unit 10, a tool change arm 2 which is driven to move up and down and rotate by the cam type drive unit 2, and a magazine tool bot 5. The gear 6 of the output shaft of the motor BM with a brake meshes with the gear 8 of the input shaft 9 of the drive section 10 via the idle gear 7. On the input shaft 9 are a detection dog D1 for stopping the tool change arm 2 and a detection dog D1 for the tool clamp.
2, and a proximity sensor S detects both the dogs. Said sensor and dog r)1. The detection timing of the dog D2 is such that the detection of the dog D1 is the timing when the tool changing arm 2 returns to the standby position, and the detection of the dog D2 is synchronized with the timing of the reversal of the tool changing arm, as shown in FIG. Therefore, the unclamp timer T1, which operates simultaneously with the activation of the tool change arm 2, unclamps the tool 2 in a timely manner, and the clamp timer T2 is activated from a specific rotation angle of the tool change arm by the sensor detection of the detection dog D2. and clamp it in a timely manner.

Next, the main #I3 is equipped with an unclamping device 4 at its tail end, and has a known configuration in which limit switches LL and L2 sense clamping and unclamping and send a completion signal to the control section C. The unclamping device 4 includes a hydraulic cylinder, and is configured such that a drive unit 10 operates an electromagnetic switching valve 11 in response to a start command from each timer Tl, T2 controlled by a control unit C and a sensor S. The control unit C is the central part of the programmable controller PC, and when it receives a tool change command for the M function such as an NG Niprogram from the NC control unit, after the spindle head 1 returns to its home position, the motor B with a brake is activated.
This is a related configuration in which a start command is sent to the start/stop control unit 12 of the controller to start the ATC operation, and at the same time, excite the timer T1. When the timer T1 counts for a predetermined period of time, the drive unit 10
operates the electromagnetic switching valve 11- to unclamp it, excites the timer T2 by the dog detection of the sensor S, and counts for a predetermined time. The driving unit 10 operates and clamps the electromagnetic switching valve 11. Finally, when the sensor S detects the dog []1, the control unit C controls the motor B with the brake.
A stop command is sent to the start/stop control unit 12 of M to suddenly stop the motor and end the ATC operation.

The control system sends a termination signal to the NC control device to terminate a series of operations.

Next, the first. ．． The tool change action is explained in Figure 2.5.

In response to the tool change command of the M function, the control unit C sends a start command to the control unit 12 to start and stop the motor B R-4 with a brake, and starts the motor suddenly, while starting the timer 1. and starts ATC operation. Arm 2 is at 240 degrees position (time axis 60 degrees) from the standby position of 180 degrees (axis 0 degrees)
Rotate to the tool gripping position and grip the tool. (Time axis 8
0 degrees), the time T1 is amplified by 1±α, and the drive unit 10 operates the electromagnetic switching valve 11 to unclamp it. After this, the arm 2 starts to move downward around (time #100 degrees), and around (time axis 130 degrees) the tool can be pulled out from the spindle 3 and tool pot 5.
The reverse rotation of As 2 (from the 240 degree position to the 60 degree position) begins. This reversal operation is completed near (time axis 250 degrees), but C time axis 1 where the downward movement of A% 2 has ended
60 degrees), the sensor S detects the detection tongue D2 and excites the timer T2. The time up t2±β of the timer T2 is determined after the reverse rotation of the arm 2 (time axis 25
0 degrees to 300 degrees), immediately after the upward movement of arm 2 is completed (time axis 290 degrees), and the tool (
clamp). After this (300 degrees on the time axis), the arm starts turning to the standby position (O degree position), and when the sensor S detects the stop dog D1 at the standby position (0 degree position, 360 degrees on the time axis), the control unit C sends a stop command to the start/stop control unit 12 of the motor with brake BM, suddenly stops the motor, ends the ATC operation, and sends an NG end signal.
The data is sent to the control device to complete the series of operations. Above timer T
The excitation timing of I and T2 is ±α,
Make t±β as short as possible, and reduce the error factor time ±α, ±β.
Efforts have been made to minimize the value. Therefore, if the excitation timing of the timer T2 is matched to the timer T1 as shown in FIG. 4, the error factor time ±β will be expanded and a clamp error will occur.

In addition, by suddenly stopping the start and stop of the motor BM with a brake,
If you perform TC operation and do not execute iI: Accurate fixed position stop, time-up L± will occur in the next ATC operation.
α and [±β are distorted, making it impossible to perform clamp/unclamp operations. Therefore, as shown in FIG. 3, the inventor of the present invention reduced the ratio of the motor braking force to the motor torque value of the motor BM with a brake from the standard time of "1".
, 7,0° 8.0.9J increases the variation angle of the arm stop position, and increasing the ratio rl, 1, 1.2, 1.3° 1.4, 1.5J increases the arm's variation angle. It has been experimentally confirmed that the variation angle of the stop position becomes smaller and settles down to an almost constant value from a value exceeding rl, 2J, and in the present invention, a special motor with this ratio set to "1.2 or more" is used. We are hiring.

The present invention is not limited to the above-mentioned embodiments, and design changes and implementation changes may be made within the gist of the invention. Second, of course.

"Effects" The present invention has the following advantages: (1) The tool clamping timing is controlled in synchronization with the turning movement of the tool changing arm using a timer that operates from a specific angle during the turning movement of the tool changing arm.
The turning mechanism of the tool changing arm and the tool unclamping mechanism can be electrically completely synchronized, and there is no need to modify either mechanism at all.

(2) Furthermore, a detection dog for stopping the tool exchange arm and a detection dog for the tool clamp are provided on the rotating shaft of the motor drive system that operates the tool exchange arm, and the detection dog for the tool clamp is activated by sensor detection. Since the tool clamping timing is synchronously controlled using a timer, the turning mechanism of the tool changing arm and the tool unclamping mechanism can be electrically completely synchronized. Immediately before tool clamping, the clamp timing is controlled again using the timer setting, ensuring highly accurate and highly stable unclamping and clamping operations. (3) The motor with a brake that operates the tool changing arm has a drive system that increases the braking force value by at least 20% relative to this torque value, and a detection dog for stopping the tool changing arm is installed on the rotation axis of the drive system. and a detection dog of the tool clamp, and synchronously controls the Y-clamp timing using a timer that operates the detection dog of the tool clamp by sensor detection.

Since the L exchange arm is suddenly stopped by the motor with a brake upon detection of the stop detection dog, the tool exchange art t1
In addition to fully electrically synchronizing the rotation mechanism and tool unclamp mechanism, even if there are variations or instability in the rotation movement of the tool change arm, the clamp timing can be controlled again using the timer setting just before tool clamping. is,
Highly accurate and highly stable unclamping and clamping operations are guaranteed. Furthermore, even if there are variations or instability in the turning movement of the tool changing arm 11, the turning stop f device of the tool changing arm is accurately controlled, and the first turning movement of the tool changing arm is also stable. It has all the functions required.

[Brief explanation of drawings]

Fig. 1 is a block diagram disclosing the automatic tool changer and electrical processing of the present invention, Fig. 2 is a time chart showing the relationship between ATC operation and clamping, and Fig. 3 is a braking characteristic diagram of a motor with a brake. , FIG. 4 and FIG. 5 are flowcharts showing the relationship between the ΔT C211 operation and the clamp. 2...Tool exchange arm, 3...Main shaft, 5...Two/leverbutton, 100...ATC device, 10...Cam type drive section, BM...Motor with brake, D1. 1) 2...Dog, S...Sensor, 'Fl, T2.・
・Evening, (Ma, C...Control unit, ±1...Solenoid switching valve. 12...Start/stop control unit.

Claims (3)

[Claims] (1) An unclamp timer that operates at the same time as the tool exchange arm starts unclamps the tool, while a clamp timer that operates from a specific angle while the tool exchange arm is rotating determines when the tool will be clamped. An automatic tool change operation method characterized by synchronous control. (2) A detection dog for stopping the tool exchange arm and a detection dog for the tool clamp are provided on the rotating shaft of the motor drive system that operates the tool exchange arm, and an unclamp timer that operates simultaneously with the activation of the tool exchange arm is used to control the tool. While unclamping the tool, a clamp timer that is activated from a specific rotation angle of the tool exchange arm is activated by sensor detection of the detection dog, and the tool clamp timing is controlled in synchronization with the operation of the tool exchange arm. Device. (3) The motor with a brake that operates the tool exchange arm has a drive system that increases the braking force value by at least 20% relative to this torque value, and a detection dog for stopping the tool exchange arm and a tool are installed on the rotation axis of this drive system. The tool is equipped with a clamp detection dog, and unclamps the tool with an unclamp timer that operates at the same time as the tool exchange arm is activated, while a clamp timer that operates from a specific rotation angle of the tool exchange arm is activated by sensor detection of the detection dog. , an automatic tool changer characterized in that, in addition to controlling the tool clamp timing in synchronization with the operation of the tool change arm, the tool change arm is suddenly stopped by the motor with a brake that increases the braking force upon detection of the stop detection dog. .