JPH058042Y2 - - Google Patents

Description

[Detailed description of the invention] (Industrial application field) The invention has a drilling process using a drill.
For example, in an unmanned automatic machine such as a transfer machine, when drilling holes into two types of workpieces that have the same external dimensions and shape but are made of different materials and have different hardnesses, The present invention relates to an adaptive control device for drilling that determines the hardness and, in turn, the material of a workpiece, and sets cutting conditions suitable for each material, namely, the number of rotations of the drill and the feed rate of a drill feed unit.

(Prior art) Conventionally, in the case of machining two types of workpieces that have the same external dimensions and shape but are made of different materials, for example, if the workpieces are cast in a lot and the two types of workpieces are A and B, first A The number of seeds in one lot is set on a counter, and cutting conditions are changed based on the fact that the workpiece becomes type B due to the counter increase.
Or, for example, fix the cutting conditions to the unfavorable side, that is, set the cutting conditions to match the hard workpiece A, B.
The cutting conditions were kept constant no matter which workpiece was flowing. However, the conventional former method requires a discrimination device for different workpieces, and in the case of transfer machines, it requires a shift register for workpiece type discrimination signals to each station and a selector switch for switching workpiece types, making it complicated and expensive and requiring maintenance. It was difficult. In the latter case, even workpieces with low hardness are processed under the same conditions, resulting in a longer cycle time.

(Problems to be solved by the invention) The purpose of the invention is to change the cutting conditions to the disadvantageous one as described above in machining two types of workpieces that have the same external dimensions and shape but are made of different materials. Adaptive control of drilling that eliminates the cycle time loss caused by fixing, and allows easy and inexpensive cutting conditions to be set for each of the two types of workpieces, rather than the complicated and expensive process that occurs when drilling by lot. The goal is to provide equipment.

(Means for solving the problem) Therefore, the present invention includes a drill feed unit supported on a table so as to reciprocate on the table by a ball screw supported at a fixed position on the table; A spindle motor with a pole change that rotates the drill spindle supported on the feed unit, a feed DC motor that rotates the ball screw, and a feed DC motor that detects the current flowing to the DC motor and converts the current to a corresponding voltage to generate the corresponding voltage. A shunt that outputs as a signal, a voltage sensor that inputs the voltage signal and compares it with a set voltage to determine the work type and outputs it as a work type signal, and a voltage sensor that inputs the work type signal and outputs it as a work type signal. A programmable controller that outputs a pole change signal and inputs a feed unit feed rate change signal to a control device for the DC motor.

(Function) With this configuration, when drilling two types of workpieces with different hardnesses, the hardness of the workpieces is determined by the voltage sensor via the shunt instead of the drill thrust, and the hardness of the workpieces is automatically determined by the voltage sensor via the flow divider. This has become an adaptive control device for drilling, in which changes in drill rotational speed and drill feed unit feed rate that match the material of each workpiece are appropriately controlled via a programmable controller.

(Embodiment) Next, an embodiment of the present invention will be described with reference to the drawings. The adaptive control device for drilling based on the present invention is as shown in FIGS. 1 and 2. A ball screw 16 rotated by the motor 4 is supported at a fixed position.
The ball screw 16 feeds a drill feed unit 17 supported on the table so that it can reciprocate on the table 16, and the DC motor 4 rotates to cause the drill feed unit 17 to reciprocate. A drill spindle 1 is supported on the feed unit 17, which is rotated by a spindle motor 3 (4P/6P) with a pole change 19 whose rotational speed can be changed by a pole change 19, and has a drill attached to its tip. has been done. As shown in FIG. 1, the control section includes a shunt 5 that detects the thrust current of the feed DC motor 4, converts it to a corresponding voltage, and outputs it as a corresponding voltage signal 23, and a shunt 5 that inputs the voltage signal 23 and outputs the set voltage. A voltage sensor 6 outputs a work type signal 20 in comparison with the work type signal 2.
0 and outputs a pole change signal 21 that instructs the pole change 19 to change the number of poles (4P or 6P), and also outputs a pole change signal 21 that instructs the pole change 19 to change the number of poles (4P or 6P).
That is, the programmable controller 7 outputs a feed unit feed speed change signal 22 that instructs conversion of the feed control program for 4P and 6P of the feed control program of the NC control section 8 that controls the servo control section 9 and changes it to an appropriate feed program corresponding to the number of poles. and, including. The set voltage of the voltage sensor 6 can be set by the volume 15. The spindle motor 3 that has been pole-converted by the pole changer 19 rotates at an appropriate rotation speed according to the type of workpiece, and the DC motor 4 rotates the ball screw 2 at an appropriate rotational speed according to the type of workpiece specified by the servo control unit 9. The feed unit 17 is rotated to feed the feed unit 17 at an appropriate speed.

In operation, the feed cycle of the feed unit is such that the feed unit processes step feeds, including a first step 10 and a second step 11, as shown in FIG. In the first step 10, machining is performed using a 6P motor with poor cutting conditions (low speed rotation, low speed feed, long cycle time), and the type of workpiece is determined based on the drill thrust current during the first step machining. It's like that. That is, the fourth
When the cutting current is 12 as shown in Figure A, the voltage is low, so adaptive control of drilling is performed to perform high-speed rotation machining as a 4P motor, and when the cutting current is 13 as shown in Figure 4B, the voltage is low. , the current is higher than the cutting current 12, and the difference is determined as a thrust current difference 14, and adaptive control of drilling is performed so that the 6P motor rotates at a low speed. Based on this determination, as shown in FIG. 3, from the second step onwards, the machining cycle is repeated using the motor for 4P or 6P, which has been converted as appropriate cutting conditions.

(Effect of the invention) Due to the configuration described above, the adaptive control device for drilling according to the invention can drill two types of workpieces that have the same external dimensions but different hardness due to different materials. When drilling holes,
There is no need for a discrimination device for different workpieces, and in the case of a transfer machine, there is no need for a signal shift register for each workpiece type to each station, and there is also no need for a selector switch to change the workpiece type, so conventional lot flow can be processed. It is simpler, cheaper, and easier to maintain than conventional equipment. Random flow of workpieces is now possible. Furthermore, since machining is always performed under appropriate cutting conditions, the required minimum machining cycle time is achieved, reducing cycle time and increasing production volume. Furthermore, even when the machining capacity decreases due to the life of the drill, the appropriate cutting conditions are automatically and adaptively controlled, so the time for replacing the drill, that is, the life of the drill is extended. In particular, according to the present invention, the motor for rotating the drill spindle does not require an expensive motor such as a servo motor, making it possible to significantly reduce equipment costs and maintenance costs.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing the control section of the apparatus according to the embodiment of the present invention, Fig. 2 is a schematic plan view showing the mechanical part of the embodiment of Fig. 1, and Fig. 3 shows the feed feed of the apparatus shown in Fig. The graph shown in FIG. 4 is a graph showing the current of the DC motor during operation of the apparatus of FIG. 1...Drill spindle, 2...Ball screw,
3...Spindle motor, 4...DC motor,
5... Flow divider, 6... Voltage sensor, 7...
...Programmable controller, 16...Table, 17...Drill feed unit, 18...
...DC motor control device, 19...Pole change, 20...Work type signal, 21...Pole change signal, 22...Feed unit feed speed change signal, 23...Voltage signal.

Claims (1)

[Scope of utility model registration request] A drill feed unit supported on the table so as to reciprocate on the table by a ball screw supported at a fixed position on the table, and a spindle with a pole change that rotates the drill spindle supported on the feed unit. A motor, a feed DC motor that rotates the ball screw, a shunt that detects the current of the DC motor, converts the current into a corresponding voltage, and outputs it as a corresponding voltage signal, and inputs the voltage signal to set the voltage. A voltage sensor that determines the work type by comparing the data and outputs it as a work type signal, and a voltage sensor that inputs the work type signal and outputs a pole change signal to the pole change, and controls the feed unit feed rate to the control device of the DC motor. An adaptive control device for drilling, comprising: a programmable controller that inputs a change signal.