JPH048445A - Numerical control system with automatic tool changing function - Google Patents

Abstract

PURPOSE:To dispense with any addition and adjustment of a contactless switch conformed to various operation modes by setting the tool changing operating position data to a means capable of setting each individual operation conformed to these various operation modes and thereby performing operational control over a tool change arm. CONSTITUTION:A tool change control part 52 receives a tool change command from a main control part 51, controlling the operation of an automatic tool changer, and an absolute value detector 41 detects an operating state of a change arm 35 and the signal is inputted into the tool change control part 52 via an absolute value detector interface 58. An operation zero position of a tool changer arm is set by a tool change operating position setting part 59, and position data for automatic tool changer operation is set by a tool change operating position data setting part 60. Thus, tool change operation can be easily performed by only changing the data of the tool change operating position data setting part 60 in relation to various operation modes such as those of ordinary cycle mode, one step feed mode and one step return mode.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a numerically controlled machine tool such as a machining center having an automatic tool changer (hereinafter referred to as ATC).

Conventional technology Recently, cam-type ATC has been developed to reduce tool change time.
is increasing. Figure 5 is a block diagram of a cam-type ATC and a control device for tool exchange operation (hereinafter referred to as ATC operation). The arm 101 is connected to the drive shaft 103 by a drive shaft 103 which is decelerated and driven by a drive motor 1゜2, and by cams 105 and 106 which are rotated at a constant speed.
One rotation of the tool completes one cycle of a series of tool exchange operations. A dog group 107 is attached to the drive shaft 103, and a proximity switch group 108 is provided near the dog group 107 to detect the operating position of the tool change arm 101 using the rotation position chamber of the drive shaft, and is used to control the TC operation. It is used. In the block diagram part, 111 is a main control unit that processes the entire numerical control, 112 is a tool change control unit that receives a tool change command from the main controller mm1ll and performs ATC operation control, and 114
115 is a solenoid that drives the attachment and detachment of the tool; 113 receives the output signal of the tool change control unit 112;
Output to the drive motor 102 and the tool attachment/detachment solenoid 115, and the proximity switch 108. Limit switch 114
This is an input/output control unit that inputs the status of

FIG. 6 is a diagram showing an example of the ATC operation sequence based on the block diagram, in which the rotation angle (a) of the drive shaft 103 is 0.
While changing from 6 to 360@, the tool exchange arm 101
indicates that the motor performs one cycle operation, and the motor drive (f) is started from the original position θ1 of the tool exchange arm in accordance with the tool exchange command (i). Along with this motor drive (f), the tool clamping operation is performed and the tool clamping position if (d
) turns OFF, the tool clamp output signal (g) is turned OFF. The tool clamp state input signal (h) is OFF at the timing θ when the 0th order tool clamp [>2 position (e) turns OFF. After confirming this, pull out the tool, rotate it 180", and then execute the tool insertion operation. Next, at timing θ4 when the tool clamp position (d) turns ON, the tool clamp output signal (g) is turned ON.
Execute the tool clamping operation and check the tool clamping position f(e
) is turned ON, it is recognized that the tool clamp state input signal (h) is ON, and the escape operation of the tool exchange arm 101 is executed. Furthermore, the motor stop position (
At timing θ6 when C) turns ON, the motor drive output signal (
f) is set to 0FFL, and the tool exchange arm is stopped at the original position θ1. And α in the figure indicates that the tool clamp output signal <g) is O
After turning OFF, the tool clamp state input signal (h) turns OFF.
β is the rotation angle of the drive shaft 103 until the tool clamp output signal (g) turns ON until the tool clamp state input signal (h) turns ON, γ
is the rotation angle of the drive shaft 103 from when the motor drive output signal (fl turns OFF until the motor stops), and when the speed of the drive motor 102 is changed, both αβ and γ change. Therefore, when the speed of the drive motor is changed If α=θ, -θ8.β
-θ, -θ4γ=θ1-θ6 +360 degrees, at least θθ4. It is necessary to change the timing of each of θ, and therefore a proximity switch must be added to detect the motor stop position (C) and tool clamp position (d). The same applies to the case where the drive motor 102 is reversed to return the tool exchange arm 101, and each operation timing is 02 to θ.

Since these timings are shifted, a proximity switch must be added to detect these timings.

Problems to be Solved by the Invention The method of detecting the position of tool exchange arm operation using a proximity switch as described in the prior art requires the addition and adjustment of a proximity switch when the tool exchange speed is changed or reverse operation is performed. As the number of actions of the proximity switch increases, malfunctions and failures occur more frequently, and the machine must be disassembled, repaired, and readjusted each time.

Additionally, if the power is turned off while the tool change arm is in the middle of operation, the detailed rotation position of the tool change arm cannot be detected when the power is turned back on, making it difficult to return the tool change arm to its original position. There were problems.

The present invention has been made in view of the above-mentioned problems of the conventional technology, and its purpose is to eliminate the need to add or adjust proximity switches according to various operation modes, and further improve ATC operation. Automatic tool change +1 that allows the tool change arm to easily return to its original position even if the power is turned off midway! ! The aim is to provide a numerical control device with this function.

Means for Solving the Problems In order to achieve the above object, the numerical control device having a tool exchange function according to the present invention has a tool magazine for storing a plurality of tools and a tool attachment/detachment mechanism. In a numerical control device having an automatic tool changing function, the tool changing means is driven, and the tool changing means is capable of changing the tool in a series of operations in which the turning operation and the tool attaching/detaching operation of the tool changing arm are performed during one revolution of the drive shaft. The apparatus includes a driving means and an absolute position detecting means provided on the drive shaft for detecting the position of the series of operations, and controls a series of operations for tool exchange.

In addition, the series of operations for tool exchange has at least three operation modes: normal cycle mode, manual one-step mode, and manual one-step return mode, and means for setting individual operation positions corresponding to the operation modes is provided. This is used to control tool exchange operations.

The desired data is read out from the set tool change position data in the tool change operation position data setting section, which can set individual operation positions corresponding to the action operation mode, and the rotation angle of the drive shaft is determined by the absolute position detector. The detection controls the movement of the arm for tool exchange, and the 360' rotation of the drive shaft controls a series of ATC operations.

In addition, even if the power is cut off while the tool change arm is in operation, the current position is known by the absolute position detector, so when the power is turned on again, the tool change arm can easily return to its original position. It is possible.

Example Examples will be described with reference to FIGS. 1 to 4.

In a known machining center, a saddle 2 is placed on a guide provided on a bed 1 in the front-rear (Y-axis) direction so as to be movable and positioned, and a saddle 2 is placed on a guide provided on the saddle 2 in the left-right (X-axis) direction. A table 3 is placed so that it can be moved and positioned. Further, a column 4 having a guide 4a in the vertical (Z-axis) direction is erected on the upper rear side of the bed 1, and a spindle head 5 is mounted on the Z-axis guide 4a so as to be movable and positionable. The main shaft 6 is rotatably supported by a plurality of bearings (not shown). A tool magazine device 7 is attached to the left side of the column 4, and an ATC 8 is attached between the main shaft 6 and the tool magazine device 7.

The tool magazine device 7 has a plurality of magazine pots 11 for storing the tools T horizontally and facing left, and after indexing the magazine pot designated by the NC to a lower tool exchange position, it indexes the magazine pot 90' (not shown) to the lower tool exchange position. The rotating mechanism allows it to rotate parallel to the main axis.

A clamp pin 12, which is removably engaged with the neck of the pull stand Ta of the tool T, is movable in the axial direction in a perpendicular hole drilled from the outside in the back hole of the tapered hole 11a for attaching the tool of the magazine pot 11. is inserted into. The tip of the clamp pin 12 is always urged to protrude by a spring (not shown), and when it is pushed out, it is in a clamped state, and when it is pushed in, it is in an unclamped state, and is fitted into a hydraulic cylinder 13 provided in a magazine frame (not shown). It is pushed in by the piston mouth/throat 14 against the force of the spring, and the movement of the dog 15 at the rear end of the piston rod 14 outputs the 1rll U2 signal for clamping and unclamping from the limit switches LSI and LS2.

A drive motor 17 is attached to the upper surface of the frame 16 of the ATC 8, and a gear IB is attached to the output shaft 17a of the drive motor 17.
A gear 21 is meshed with the gear 18, and the gear 21 is fitted onto the shaft of a shaft-equipped bevel gear 19 that is rotatably provided parallel to the output shaft 17a. The shafted bevel gear 19 is a bevel gear 2 that is fitted onto a drive shaft 23 that is rotatably supported by a fixing pin 22 fixed to the frame 16 via a plurality of bearings.
It is meshed with 4. A gear 25 is fitted onto the drive shaft 23 adjacent to the bevel gear 24, and the gear 25 is connected to the frame 16.
It meshes with a gear 28 that is integrated with a grooved cam plate 27 for inserting and extracting the exchange arm that is fitted onto a cam shaft 26 that is rotatably supported by the cam shaft 26, and the gear 2528 is formed to have the same number of teeth.

Furthermore, the camshaft 26 is equipped with a roller cam disk 2 for rotating the exchange arm.
9 is fitted adjacent to the grooved cam disc 27, and a sleeve 31 is mounted on the frame 16 at a position corresponding to the roller cam disc 29, at right angles and perpendicular to the cam shaft, by a plurality of bearings (not shown). Rotatably supported. and sleeve 3
Turret roller followers 32 are arranged radially at equal intervals on the outer circumference of 1.
is rotatably supported. And roller follower 3
2 is engaged with a cam groove 29a including a twisted cam groove portion of the roller cam disk 29, and the sleeve 3 is engaged with the rotation of the cam shaft 26.
1 is intermittently rotated approximately 90° and 180'. Further, a spline is carved in the center hole of the sleeve 31, and an arm shaft 34 having an integral spline shaft 34a is fitted into the spline hole so as to be movable in the axial direction. A shaped tool change arm 35 is fixedly attached. A bracket (not shown) is fixed to the inside of the frame 16, and the rear end of the exchange arm insertion/removal lever 36 is pivotably supported on this bracket. A roller follower 37 provided on the side surface of the central portion of the lever 36 is engaged with a grooved cam 27a of the grooved cam disc 27, and the tip of the lever 36 is provided so as to be movable in the axial direction parallel to the arm shaft 34. The notch groove 38a of the connecting shaft 38 is engaged with the notch groove 38a. This connecting shaft 3
8 and a spline shaft 34a are fixed by a connecting piece 39, and the arm shaft 34 is moved in the axial direction by rotation of the grooved cam disk 27, so that a tool can be inserted or removed.

In this way, the series of ATC operations by the exchange arm 35 are as follows:
A cycle is completed by turning the drive shaft 23 through 360 degrees, and an absolute position detector 41 is attached to the tip of the drive shaft 23 to detect the turning angle.

On the other hand, the tip of the through hole of the main shaft 6 is formed into a tapered hole for mounting the taper shank part Tb of the tool T, and a collet 42 that removably holds the pull stud Ta is inserted into the back hole following this tapered hole in the axial direction. It is movably inserted. The collet 42 is fitted into the main shaft through hole so as to be movable in the axial direction, and is attached to the tip of a tension fli 44 which is always biased upwardly by a disc spring 43. When the piston rod 46 of the hydraulic cylinder 45 fixed to the upper surface of the crown shaft head 5 moves and the tension rod 44 is pushed in against the force of the disc spring 43, the collet 42 is opened and pulled at the bow end surface. By pushing the stud Ta, the tool T is pushed out slightly from the spindle taper hole, and the piston rod 4
By dog 48 fixed to 6, limit switch LS3
．． LS4 is activated and a confirmation signal is output. The source pressure P is switched and supplied to the hydraulic cylinders 13 and 45 by an electromagnetic switching valve 47 having a solenoid SQL1.

Next, a block diagram section of the ATC operation control system shown in FIG. 1 will be explained.

51 is a main control unit that processes the entire numerical control B; 52 is a tool change control unit that receives a tool change command from the main control unit 51 and controls the ATC operation; and 41 detects the operating state of the above-mentioned change arm 35. Absolute value detector, 58 is absolute value detector 4
1 is an absolute value detector interface for inputting the signal from 1 to the tool change control unit 52, 59 is a tool change operation home position setting unit that sets the operation home position of the tool change arm, and 60 is a setting unit for setting position data for ATC operation. The tool change operation position data setting unit LSI to LS4 are each limit and 7 toss inches, 17 to detect the tool clamp and unclamp states mentioned above.
is the aforementioned drive motor, 5OLI is the aforementioned solenoid, and 5
Reference numeral 3 denotes an input/output control section which receives an output signal from the tool change control section 52 and outputs a signal to the drive motor 17 and a solenoid SQL for attaching/detaching tools, and also inputs the states of the limit switches LSI to LS4.

Next, the fourth circle is a diagram showing an example of a tool exchange operation sequence. In this figure, the data of the tool exchange position data setting section 60 is This indicates that tool exchange operations can be easily performed by simply making changes. As shown in the figure, the normal cycle mode e and the 1-step feed mode f are set according to the rotation angle a of the tool exchange arm drive shaft 23.
Execute exchange arm feed operation and return mode by 1 step
performs exchange arm return operation C, which is the opposite of this. In these tool exchange cycles, the original position of the tool exchange arm 35, the tool unclamp operation position, the tool unclamp operation v/i recognition position, the tool clamp operation position I, the tool clamp confirmation position, and the drive motor stop. The position and position are respectively held as tool position data, and the drive shaft rotation angle a is detected by the absolute value detector 41 to control the operation of the tool exchange arm 35. Since the rotational speed of the drive motor 17 is different between the normal cycle mode and the 1-step feed mode, the tool exchange position data for each operation timing is different, and the 1-step return mode is different from the normal cycle mode e and the 1-step feed mode f. , the exchange arm forwarding operation is performed, whereas the exchange arm return operation C performs the opposite operation, so the tool exchange position data for each operation timing is changed. The plurality of tool exchange position data are set in the tool exchange operation position data setting section, and desired data is called up as necessary.

The current position of the tool changing arm 35 is detected by the absolute value detector 41, so even if the power is turned off while the tool changing arm is turning, the memory of the current position will not be lost and the power can be turned on again. At times, the exchange arm 35 can be immediately returned to its original position from mid-swing.

Effects of the Invention Since the present invention is configured as described above, it produces the following effects.

A series of movements of one revolution of the drive shaft consisting of a cam mechanism, etc.
An absolute position detector is installed on the drive shaft of the tool exchange means that performs tool exchange to detect the current position of the drive shaft, and the tool exchange operation position data is set in the means that can set individual operations corresponding to various operation modes. Since I took care to control the movement of the tool exchange arm, all I had to do to adjust the movement timing of the tool exchange arm was to set the tool exchange arm's original position.
Installation of a conventional proximity switch eliminates the need for adjustment work.

Also, when changing the speed of the tool changing arm or performing a reverse cycle of the tool changing arm, the tool changing arm movement position can be adjusted. Proper operation timing of the tool exchange arm can be obtained by simply changing the data, eliminating the need for adding and adjusting proximity switches as in the past. Furthermore, since there is no proximity switch, accidents due to malfunction or failure of the proximity switch are eliminated.

Furthermore, even if the power is turned off while the tool exchange arm is in operation, the tool exchange arm can be easily returned to its original position when the power is turned on.

[Brief explanation of the drawing]

Fig. 1 is a structural diagram of the tool changer including a partial perspective view of this embodiment and a Bronk diagram of the control system, Fig. 2 is a cross-sectional view of the drive section of the tool changer of this embodiment, and Fig. 3 is a diagram of the control system. Fig. 4 is a diagram showing an example of the tool changing operation sequence of this embodiment, and Fig. 5 is a structural diagram of a conventional tool changing device including a partial perspective view, and a program of the control system. ,
FIG. 6 is a diagram showing an example of a conventional tool exchange operation sequence. 6. Main shaft 7. Tool magazine 8. Tool changer 17. Drive motor 23. Drive shaft 35
・・Tool exchange arm 41 ・・Absolute position detector 60 ・・Tool exchange operation position data setting section Fig. 3

Claims (2)

[Claims] (1) In a numerical control device that has a tool exchange function that automatically exchanges tools on a spindle that has a tool magazine that stores a plurality of tools and a tool attachment/detachment mechanism using a tool exchange arm, the rotation operation and tool attachment/detachment operation of the tool exchange arm are controlled. A tool changing means capable of changing tools in a series of operations during one rotation of a drive shaft, a driving means for driving the tool changing means, and an absolute position detecting means provided on the drive shaft for detecting the position of the series of operations. 1. A numerical control device having an automatic tool changing function, which controls a series of tool changing operations. (2) The series of tool exchange operations has at least three operation modes: normal cycle mode, manual 1-step mode, and manual 1-step return mode, and means that can set individual operation positions corresponding to the operation modes. A numerical control device having an automatic tool change function, characterized in that the tool change operation is controlled by providing the following.