JPH03142025A - Table moving controller for machine tool - Google Patents

Abstract

PURPOSE:To improve the accuracy of positioning by stopping once before the positioning spot, moving again after lapse of a prescribed time from the time of once stopping and preventing the vibration of the work table on the moving control of the table. CONSTITUTION:On the punch pressing machine 1 which consists of the upper and lower frames 2, 3, and the throat part to support them at the back side, the moving table 8, 9 is set on the carriage 7 which is movable to the Y direction on the guide rail 5, 6, the cross slide 15 which is movable to the X direction is provided and the work 11 is held with the work holder 13, 14. The controlling part 40 is set on the throat part 4 and the carriage driving device 35 is connected. When the moving tables 8, 9 (the carriage 7) reach the once stopping position before the positioning point, this is stopped once and after lapse of the prescribed time, this is moved to the positioning spot. Therefore, the shortening of cycle time and the high accuracy of positioning are realized.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a table movement control device that controls the movement of a table of a machine tool on which a workpiece is placed.

[Conventional technology]

Here, a punch press machine will be explained as an example of a machine tool. A punch press machine places a plate on a table, moves it, and processes it with a processing head. The table is driven by a servo motor via a ball screw, and is moved to a predetermined position based on control from the control unit. Thereby, the plate material is placed at a predetermined position with respect to the processing head, and the processing head performs a predetermined processing on the plate material.

A ball screw for moving the table is provided in a cantilevered structure on one side of the table, and a guide rail is provided on the other side.

[Problem to be solved by the invention]

When positioning the work table of a punch press machine as described above, the drive side provided with the ball screw can be stopped at a desired position without vibration. However, the movement of the table tends to be delayed on the side opposite to the side where the ball screw is provided (hereinafter referred to as the driven side), and this driven side may vibrate when stopped.

If vibrations occur during table positioning in this way, not only will highly accurate positioning not be possible, but processing will not be possible until the vibrations subside, resulting in a longer cycle time.

Note that if the moving speed of the table is slowed down, the table can be stopped without vibrating as described above, but the working time becomes longer.

The purpose of this invention is to be able to quickly stop the table on which the work is placed, thereby shortening the machining cycle time, and to perform high-precision positioning. The purpose is to provide a control device.

[Means to solve the problem]

A table movement control device for a machine tool according to the present invention is a device for controlling the movement of a table of a machine tool on which a work is placed, and includes a movement mechanism and a control means.

The moving mechanism applies a moving force to one side of the moving table to move the table. Further, the control means temporarily stops the table when the table reaches a temporary stop position before the positioning point, and moves the table again to the positioning point after a predetermined period of time has elapsed.

[Effect]

In this invention, when there is a command to move the plate material, the table is moved by the moving mechanism, and the desired position of the workpiece is positioned in the processing section.The daple is moved by receiving a moving force on one side. I am made to do so.

During the movement of the table, when the table reaches a temporary stop position set before the positioning point, the table is stopped once. Then, since movement tends to be delayed on the driven side of the table, this driven side portion crosses the temporary stop position and reaches the original positioning point by stopping at -.

Then, when the table is about to vibrate to the opposite side from the original positioning point, the table is moved again to the positioning point.

As a result, the driven side portion of the table no longer vibrates and quickly stops at the positioning point.

Note that the temporary stop position before the positioning point and the time from the - time stop to the re-movement are set in accordance with the moving distance of the table.

〔Example〕

1 and 2 show a punch press machine employing an embodiment of the present invention. In the figure, a punch press machine 1 mainly includes a lower frame 2, an upper frame 3 disposed above the lower frame 2, and a throat section 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 5.6 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). Fixed to the carriage 7 are movable tables 8.9 arranged on both sides of the fixed table 10. The carriage 7 has a plate material 11
A cross slide 15 on which a pair of work holders 13 and 14 for gripping the workpiece is mounted is provided so as to be movable in the left-right direction (X-axis direction).

A moving mechanism for moving the carriage 7 in the Y-axis direction is arranged below the moving table 9.

The movement mechanism of the carriage 7 is composed of a servo motor 16, a ball screw I7 connected to the servo motor 16, and a ball nut 18 screwed into the ball screw 17. The ball nut 18 is fixed to the lower surface of the movable table 9.

On the other hand, in the carriage 7, a movement H+, t for moving the cross slide I5 in the X-axis direction is arranged. The movement mechanism of the cross slide 1'15 is composed of a servo motor 20 disposed at the left end of the carriage 7, a ball screw 21 connected to the servo motor 20, and a ball nut 23 screwed into the ball screw 21. ing. The ball nand 23 is fixed to the cross slide 15.

The upper frame 3 is rotatably provided with an upper turret 12 on which a plurality of punches are mounted. Further, a punch head is provided within the upper frame 3 and is moved up and down by a crank mechanism (not shown). On the other hand, a lower turret 22 on which a plurality of dies are mounted is arranged on the lower frame 2 side.

These upper turret 12, lower turret 22, etc. constitute 11 machining sections, and the machining position is indicated by A in FIG.

A control panel 30 is provided on the side of the throat portion 4.
is located. The control panel 30 includes input keyboards 1-31. CR'l' 32, tape league 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 human power departments are connected. Further, the control section 40 is connected to a carriage drive device 35 including the aforementioned servo motor 16, ball screw 17, etc., and other output sections.

Next, the operation will be explained according to the control flowcharts shown in FIGS. 5A and 5B.

When the main switch (not shown) of the punch press machine 1 is turned on, in step S1 of FIG. Initial settings are made.

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 program is read. In step S4,
It is determined whether the read command step is a plate material movement command. If the command step is not a plate material movement command, the process moves to step S5, and it is determined whether the command step is a punch operation command. If the command step is not a punch operation command, the process moves to step S6, and it is determined whether it is a command to perform another process. And step S7
Now, it is determined whether all command steps of the NC program have been processed. If there are still command steps remaining, the process returns to step S3 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 moves to step S8 in FIG. 5B. In step S8, the moving distance of the plate material 11 is calculated based on the read instruction step. Next step S
9, the position A is temporarily stopped before the positioning point according to the movement distance that is the calculation result of step S8.
and - Set the time B from when it is stopped until it is moved again. The settings of A and B are performed with reference to a teaching table obtained through experiments in advance. Next, the process moves to step SIO, and the movement of the movement tables 8 and 9 (carriage 7) is controlled. In step 311, it is determined whether the work table has reached the temporary stop position A. Steps 310 and Sll are repeated until the work table reaches this IA.

When the work table reaches temporary stop position A,
The process moves from step 311 to step 312. In step 312, movement of the work table is temporarily stopped.

Next, in step S13, it is determined whether or not a time period B has elapsed since the time when the work table was temporarily stopped.If time B has elapsed, steps 313 to S
14, and moves again by the remaining moving distance H (see FIG. 4).

By performing such movement control, as shown in Fig. 4, when the work table (only the carriage 7 is shown in Fig. 4) temporarily stops at the - time stop position A, the driven side on the left side The edges tend to be slow to move, so
By this - time stop, the original positioning point S is reached by the inertia. Then, when the driven side tries to vibrate to the opposite side (lower side in Figure 4), the work table (especially the driving side)
is moved again to the original positioning point S, so the driven side does not vibrate to the opposite side and stops quickly.

When such movement control is completed, the process returns to step S3 in FIG. 5A.

If the reading step in step S3 is a punching operation, the process moves from step S5 to step S15. In step 315, the punch and die according to the command are selected by rotating the turret 12.22. After performing a punching operation in step S16, the process returns to step S3 again. If the instruction step read in step S3 is a step that instructs other processing, steps S6 to S1
Move to 7. In step S17, processing corresponding 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, when the driven side of the work table is about to vibrate, the driving side is moved again.
Vibration of the work table can be suppressed, it can be stopped quickly, and high-viscosity positioning can be performed.

Figures 6A to 61) show how vibration occurs when the work table is moved in a conventional device.

These data were all measured using a turret punch press machine C2000 manufactured by Murayama Kikai.

Figure 6A (measurement conditions) shows the acceleration time constant T at a travel distance of 9 mm.
=83ms e c, Figure 6B (measurement conditions ■) is for movement i
T = 83 msec at 110 mm, Figure 6C (measurement condition ■) shows T = 100 msec at a travel distance of 10 mm, Figure 6D
Figure (Measurement strip (1■) is moving jllOmm and T=110m.
This is the case of sec.

As is clear from these figures, under the conditions, the driven side swings in the moving direction from the stop position by 0.25 mm when stopped, and returns to the desired stop position after 25 m5ec. Therefore,
In the above example, A is 0.25 mm, and +1 is 25 m5e.
c, positioning can be performed without vibration. Similarly, under condition ①, A=0.375mm, B=25mse
c, and under condition ■, A = 0.2 mm, B = 23 ms.
It should be ec. Note that in condition (3), there is no large vibration because the moving speed is slow.

[Other Examples]

(a) In the embodiments described above, the present invention was applied to a punch press machine, but it can be similarly applied to table devices in other machine tools.

〔Effect of the invention〕

As described above, in the present invention, in controlling the movement of the table, the work table is temporarily stopped before the positioning point, and is moved again after a predetermined period of time has elapsed from this 1 o'clock stop to prevent vibration of the work table. Therefore, the time required to stop the table can be shortened and positioning can be performed accurately.

[Brief explanation of the drawing]

Fig. 1 is a perspective view of a punch press machine employing an embodiment of the present invention, Fig. 2 is a partial plan view thereof, Fig. 3 is a schematic block diagram of its control section, and Fig. 4 is an operation of the above embodiment. FIGS. 5A and 5B are control flowcharts, and FIGS. 6A to 6D are diagrams showing measurement data for explaining the effects of the present invention. 7... Ki → Rinshifu, 8, 9... Moving table,
11...Work, 16...Servo motor, 17...
- Pole screw, 40...control unit.

Claims (1)

[Claims] (1) A device for controlling the movement of a table of a machine tool on which a workpiece is placed, comprising a moving mechanism that moves the table by applying a moving force to one side thereof, and a movement mechanism that moves the table by applying a moving force to one side thereof; A table movement control device for a machine tool, comprising: control means for temporarily stopping the table when it reaches a stop position, and moving the table again to a positioning point after a predetermined period of time has elapsed.