JPS6146260B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a control device for a drilling machine.

In conventional drilling machines commonly used, it takes a skilled worker to prevent troubles such as drill breakage, determine when to replace the drill, determine whether the drill is installed properly, or determine whether the drill and pilot hole are misaligned with the punched hole. Therefore, if the skill level of the worker is low, there is a problem in that work efficiency, processing accuracy, etc. are significantly reduced.

In order to solve these problems, the present invention incorporates a torque detection mechanism into the rotary drive mechanism of a drilling machine, evaluates the fluctuations in torque detected by this in relation to the diameter of the drill used, and determines the machining situation. The system is characterized in that it displays the following information and also performs optimization control on the rotational speed and feed rate of the main shaft of the drilling machine.

Embodiments of the present invention will be described below with reference to the drawings.

As shown in FIG. 1, the drilling machine controlled by the control device according to the present invention includes a rotational drive mechanism 1,
A feed mechanism 2 is driven by the rotational drive mechanism 1 and is fed by the feed mechanism 2. It includes a drill chuck 3, a drill 4 attached to the drill chuck 3, and a table 5 on which a workpiece 6 is fixed.

As shown in detail in FIG. 2, the rotary drive mechanism 1 has a rotor 11 rotating within a stator 10 of an electric motor supported by a highly rigid hollow shaft 12, and transmits torque within this hollow shaft 12. The shaft 13, which twists depending on the angle of A torque detection mechanism 14 is provided which measures the transmitted torque by detecting the torsion angle of 13. This torque detection mechanism 14
Signs such as magnets 15 and 1 are placed at 2 and 13, respectively.
6 is provided, and detectors 17 and 18 such as pickups are provided opposite to these, so that torque can be measured from the time delay in pulse signal generation at the detector 18 when a load is applied. .

Further, the feed mechanism 2 has a function of feeding the drill 4 according to the feed signal applied thereto, and also has a function of quickly returning the drill in response to a quick return signal.

Such a drilling machine is equipped with a drill diameter indicating device 19 that has a function of setting or detecting the diameter of the drill being used.
A manual dial setting device may be provided to manually set the diameter of the drill 4 attached to the chuck 3, or when the drill 4 is attached to the chuck 3, the amount of tightening of the drill fastening member in the chuck 3 differs depending on the diameter of the drill. Therefore, it is necessary to add a device that automatically detects the amount of tightening, or to store drills of various diameters in their respective predetermined positions on a drill stand that is used to remove the drill 4 from there for attachment to the chuck 3. Add a means to detect
This makes it possible to detect which diameter drill is being used.

A drill diameter instruction signal output from the drill diameter indicating device 19 is sent to a torque calculating device 20 connected thereto. This torque calculation device 20 is
The limit torque for use of the drill is calculated and output based on the instruction signal for the drill diameter, and the output is compared with the torque sent from the torque detection mechanism 14 in the evaluation device 21 at the next stage.

The torque detected by the torque detection mechanism 14 is determined when the drill 4 is properly attached to the chuck 3, there is no misalignment between the drill 4 and the pilot hole or punch hole in the workpiece, and the rotational speed n is appropriate according to the drill diameter. If the feed rate is given, it will show a substantially constant value.

During normal machining, when the torque detected by the torque detection mechanism 14 is compared with the usable limit torque given by the torque calculation device 20 in an evaluation device composed of a comparator etc., the detected torque is inevitably Therefore, the evaluation device 21 outputs a comparison result signal indicating that the torque is below the limit torque to the cutting status display device 22 and the optimization control device 23. In addition, the cutting status display device displays the fluctuating waveform of the detected torque, or performs analysis based on the fluctuating waveform to identify drill damage, wear, chucking, incorrect centering, excessive feed rate, etc. It is displayed as follows.

Further, the optimization control device 23 is configured by a microcomputer or the like, and performs feedback so that appropriate torque can be obtained for the rotational drive mechanism 1 and the feed mechanism 2 based on the signal sent from the evaluation device 21. In other words, in relation to the material of the workpiece 6 and other machining conditions set therein, the rotation speed n of the rotary drive mechanism 1 and the rotation speed n of the feed mechanism 2 are adjusted so that the torque detected by the torque detection mechanism 14 approaches the appropriate torque. It controls the feed speed. Therefore, for example, if the detected torque is sufficiently smaller than the proper torque, control is performed to increase the rotation speed n or feed speed, and when abnormal torque is detected,
Depending on the abnormality, the rotational speed of the rotary drive mechanism 1 is reduced or the drill and the workpiece are controlled to be separated from each other. Furthermore, when starting machining, it is desirable to provide rapid feed until the drill 4 reaches the surface of the workpiece 6 in order to shorten the machining time, and therefore the machining torque is detected by the torque detection mechanism 14. It can also be controlled to fast-forward through the process.

Generally, in a drilling machine, an abnormal torque based on an original drawing as exemplified below is generated.

(1) Torque increases due to decreased sharpness due to drill wear.

(2) If the chuck of the drill is inappropriate or if there is a misalignment of the axis with the prepared hole or punched hole, there may be torque fluctuations or increases in synchronization with the rotation period of the drill.

(3) When drilling through a workpiece, the resistance to feed rapidly decreases and the depth of cut increases, resulting in a rapid increase in torque.

(4) If the drill breaks for some reason, the torque will change rapidly.

Such abnormal torque has a unique fluctuation pattern depending on the cause of its occurrence. Therefore, when analyzing the cause of abnormal torque occurrence based on the fluctuation waveform of the detected torque in the cutting status display device 22, and when performing optimization control. When performing control to obtain appropriate torque in the device 23, it is only necessary to determine what kind of abnormal state pattern the above-mentioned fluctuation pattern belongs to.

Therefore, if the above abnormal torques (1) to (4) are detected, the optimization control system should take measures such as those shown in (1)' to (4)' respectively. is appropriate.

(1)' When the torque reaches a certain specified value, the rotary drive mechanism is stopped for drill replacement.

(2)' Stop the rotary drive mechanism to recheck the chucking condition of the drill and the misalignment of the axis with the workpiece.

(3)' When the torque starts to increase rapidly, immediately switch the feed speed to minute feed or quick return to prevent the drill from breaking.

(4)′ Stop the rotary drive mechanism to replace the drill.

As described in detail above, according to the control device of the present invention, it is possible to perform optimization control of machining by a drilling machine using a relatively simple device. At the same time, it is possible to automatically detect and display the causes of various troubles that were suppressing the machine, and at the same time, to eliminate the troubles, it is possible to appropriately control the rotation speed and feed speed of the main shaft of the drilling machine. Even when the level of skill is low, processing can be performed efficiently and with high precision.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an embodiment of the present invention, and FIG. 2 is a sectional view of a rotational drive mechanism having a torque detection mechanism. DESCRIPTION OF SYMBOLS 1...Rotation drive mechanism, 2...Feeding mechanism, 3...Chuck, 4...Drill, 14...Torque detection mechanism, 19...
Drill diameter indicating device, 20...Torque calculating device, 21
...Evaluation device, 22...Cutting status display device, 23...Optimization control device.

Claims (1)

[Claims] 1. A drill diameter indicating device for setting or detecting the diameter of the drill to be used on a drilling machine that performs machining by attaching a drill to a chuck that is driven by a rotary drive mechanism with a built-in torque detection mechanism and fed by a feed mechanism. , a torque calculation device for calculating a usable limit torque based on the output thereof is connected to the drill diameter indicating device, and an evaluation device for comparing the outputs thereof is connected to the torque detection mechanism and the torque calculation device, This evaluation device includes a cutting status display device that displays the machining status in relation to the above-mentioned limit torque based on the comparison results, and an optimization control of the rotation speed and feed rate of the spindle of the drilling machine based on the comparison results. A control device for a drilling machine, characterized in that it is connected to an optimization control device that performs optimization.