JPH0398742A - Control device for turret of machine tool - Google Patents

Abstract

PURPOSE:To eliminate the abrupt change of a turret rotating speed by accelerating the turret based on a rotation command and controlling a turret rotation driving means so as to decelerate it after its steady rotation at a constant speed. CONSTITUTION:A control means 40 accelerates turrets 12, 22 based on a rotation command, controlling a driving means 35 so as to decelerate after the steady rotation at a constant speed. Namely, the turrets 12, 22 are rotated by a driving means 35 and controlled so that a desired tool is located at the work position. At this time, a rotation moving period at a steady speed is once provided after the acceleration period and the deceleration is started after the specific time lapse of this constant speed period. The servodelay of the acceleration time is recovered by setting this constant speed period and also an abrupt speed change is eliminated, so the drift at the stoppage time can be restrained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application If'] The present invention relates to a turret control device in a machine tool for controlling the rotational movement of a turret I on which a tool is mounted.

[Conventional technology]

For example, in punch press processing, turret punch press machines are often used to improve work efficiency. This turret punch press machine is equipped with an upper turret and a lower turret in the processing section, the upper turret is equipped with multiple types of punch tools, and the lower turret is equipped with circular tools corresponding to each punch tool. arranged around the circumference.

When processing, punches and dies for each crete are selected as appropriate depending on the type of processing.

When selecting tools for each turret, turret 1.
The rotation of the tool is controlled to move the tool to the machining position. At this time, the rotation operation is normally performed as shown in FIG. That is, the tareno 1 is first accelerated with a predetermined time constant, decelerated after time L has elapsed, and finally stopped after time] has elapsed.

[Problem to be solved by the invention]

Generally, the inertia of the turret is large and therefore
There is often a delay in the servo control when rotating the turret. In the rotation control shown in Fig. 6, since the stop position is determined by acceleration and deceleration operations, a servo delay occurs during acceleration, and after a rapid speed change at point P, the same occurs during deceleration. A servo delay occurs. In addition to this servo delay, the large inertia of the turret makes it difficult to control the torque of the servo motor, causing the turret to wobble after stopping, causing so-called hunting. In a punch press machine, punching is performed on the hunting ψ, resulting in a decrease in processing precision.

An object of the present invention is to provide a turret control device for a machine tool that can suppress wobbling when the turret is stopped and perform machining with high precision. [Means for solving the problem] A turret control device for a machine tool according to the present invention includes:
This is a device for controlling the rotational movement of a rail on which a tool is attached, and includes a drive means and a control means.

The drive means is for rotating the turret, and the control means controls the drive means to accelerate the turret based on a rotation command, rotate it steadily at a constant speed, and then decelerate it. It is. [Operation] In the present invention, the turret is rotated by the driving means and controlled so that the desired tool is positioned at the machining position. At this time, after the acceleration period, a period of rotational movement at a steady speed is once provided, and after a predetermined period of time has elapsed from this constant speed period, deceleration begins.

By setting this constant speed period, the servo delay during acceleration is recovered, and sudden speed changes are also eliminated.
It is possible to suppress wobbling when stopping.

〔Example〕

here,]. The explanation will be given by taking a punch press machine as an example of a machine tool.

FIG. 1 shows a turret punch press machine employing an embodiment of the present invention. The turret punch press machine (hereinafter simply referred to as punch press machine) mainly uses the lower frame 2.
, an upper frame 3 disposed on the −L side of the lower frame 2, and a throat portion 4 that supports these at the rear.

A fixed table 10 is arranged at the center of the upper surface of the lower frame 2. Note that a pair of guide rails 5 and 6 are arranged on both sides of the upper surface of the lower frame 2. A carriage 7 is disposed on the guide rail 5.6 so as to be movable in the depth direction (Y-axis direction). Moving tables 8 and 9 are fixed to the carriage 7 and are arranged on both sides of the fixed table IO. The carriage 7 has a plate material 11
A cross slide equipped with l pairs of work holders for gripping is provided so as to be movable in the left and right direction (X-axis direction). The upper frame 3 is provided with an upper turret l2 on which a plurality of punch tools are mounted, and the lower frame 2 is provided with a lower turret 22 on which a plurality of die tools are mounted.

A control panel 3 is provided on the side of the throat portion 4.
0 is placed ゜ζ. The control panel 30 includes
An input keyboard }'31 CRT32, a tape reader 33, etc. are arranged.

A control section 40 as shown in FIG. 3 is disposed within the throat section 4. As shown in FIG. The control unit 40 includes a CPU, ROM, and R.A.
It is equipped with a microcomputer consisting of M, etc. The control unit 40 includes a keyboard 31 and a tape reader 33.
and other input sections are connected. In addition, the control unit 40
The turret I/drive device 35 and other output parts are connected to.

The details of each of the turrets 12 and 22 will be explained with reference to FIG.

The upper turret 12 is rotatably attached to the upper frame 3. This upper turret 12 has a sprocket.
17 is fixed, and is driven via a chain from a drive device (turret drive device 35 in FIG. 3) such as a servo motor (not shown). On the other hand, the lower turret 22 faces the upper turret l2 (
It is rotatably supported by the lower frame 2. The drive mechanism of the lower turret 22 is the drive mechanism of the upper turret 12.
The drive a is similar to the horizontal drive a, and is composed of a sprocket l8 fixed to the lower turret 22, a chain, and a drive device (not shown).

Next, the operation will be explained according to the flowcharts shown in FIGS. 4A and 4B.

When the main switch (not shown) of the punch press machine L is turned on, initial settings such as setting the work holder and turret 12.22 to the initial positions and reading the NC program from the tape reader 33 are performed in step Sl in FIG. 4A. I do. Next, in step S2, a work start command is awaited. If a work start command is input from the keyboard 31, the process moves to step S3. In step S3, the first command step of the NC programmer I is read. In step S4, it is determined whether the read instruction step is a plate material movement instruction. If not, step S
5, it is determined whether or not it is a punching operation command.

Similarly, if it is not a punching operation command, step S
6, it is determined whether the command step is a command to perform other processing. Then, in step S7, it is determined whether all command steps of the NC program have been processed, and if command steps remain, the process returns to step S3 again and the next command step is read.

If it is determined in step S4 that a command to move the plate material has been issued, the process proceeds to step S8, where the table and the like are moved to control the movement of the plate material. When this process is completed, the process returns to step S3.

If the instruction step read in step S3 is a punch operation instruction, the program moves from step S5 to step S10 in FIG. 4B. In step S10, the amount of rotation of each turret 12.22 is calculated based on the read command step. Also, based on this calculation result, the rotation speed switching timing is calculated.

Next, in step Sll, as shown in FIG. 5, the movement of each turret 12.22 is started at a predetermined acceleration rate. Then, in step Sl2, it is determined whether the switching timing has reached 11 or not. If it is determined YES in step 512, the process moves to step 313, and each turret 12.22 is rotated at a constant speed. Then, in step Sl4, it is determined whether the switching timing has reached L2, and if it is determined that the switching timing has reached t2, the process moves to step S15. Step S
At l5, the turret 12.22 is stopped with a preset deceleration time constant. When the process in step SI5 is completed, the process returns to step S3 in FIG. 4A.

If the instruction step read in step S3 is a step for instructing other processing, the process moves from step S6 to step S9.

In step S9, processing according to the command is performed, and the process returns to step S3 again. When all the steps have been read, the determination in step S7 becomes YES, and the operation of this punch press machine ends.

In this embodiment, the turret rotational speed is controlled as shown in Fig. 5 to eliminate sudden speed changes and provide a constant speed period, so that the servo delay during acceleration is recovered during this constant speed period ψ. This can prevent wobbling when stopping.

[Other Examples]

(a) In the above embodiment, a punch press machine was used as an example of a machine tool, but the present invention can be similarly applied to control of a turret in other machining tools, such as a turret lathe. can.

〔Effect of the invention〕

As described above, according to the present invention, in the rotation control of the turret, a constant speed period is provided between the acceleration pJ1 period and the deceleration period, so that sudden speed changes in the turret rotation speed can be eliminated. Furthermore, it is possible to recover the servo delay during the constant speed period, suppressing wobbling when stopped, and performing highly accurate machining.

[Brief explanation of drawings]

Fig. 1 is a perspective view of a punch press machine employing an embodiment of the present invention, Fig. 2 is a partial cross-sectional view of the turret portion thereof,
FIG. 3 is a schematic block diagram of the control unit, FIGS. 4A and 4B are its control flowchart, FIG. 5 is a diagram showing the control state of the turret, and FIG. 6 is a diagram showing the conventional control state of the turret. be. l2... L turret, 22...lower turret, 35
...Turret 1/drive device, 40...control unit.

Claims (1)

[Claims] (1) A turret control device in a machine tool for controlling the rotational movement of a turret on which a tool is attached, comprising a drive means for rotating the turret, and accelerating the turret based on a rotation command; A turret control device for a machine tool, comprising: control means for controlling the drive means to decelerate after rotating steadily at a constant speed.