JPH06170589A - Motor-driven press device - Google Patents

Abstract

PURPOSE:To minimize the variation of pressing pressure by freely turnably mounting nut parts which are corresponded to thread parts which are provided on each column and providing motors with which each nut part is turned on every column. CONSTITUTION:The nuts are turned by starting plural direct drive servo motors 11, a moving bolster 1 is lifted in the direction of an upper bolster 4 by fitting of the nuts with the thread parts of the columns 2, butting and clamping of an upper die 5 and a lower die 6 are executed. Since the driving forces of the direct drive servo motors 11 at this time are controlled by feedback control at respective predetermined values by detecting the strain of the columns 2 with sensors 12, the variation of pressing pressure is minimized. Then, the generation of resin burrs is prevented in a resin forming press machine.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transfer mechanism and a mold clamping mechanism in a press machine.

[0002]

2. Description of the Related Art As a press device using an electric motor as a power source for a conventional transfer mechanism and mold clamping mechanism, a movable bolster 1, as shown in FIG. 3, is fixed by mounting a screw 8 on the bottom of its center of gravity. The nut portion 10, which is rotatably installed on the bolsters 3 and 4, is fitted and transferred by driving the electric motor 7.
A method of performing mold clamping is known.

However, in a press of a medium size or larger using a mold having a large working area, the mold and the bolster are pressed mainly by elastic deformation at a vertical portion and a peripheral portion of the working surface of the mold with respect to a screw axis. It has the drawback that the pressure will fluctuate, causing problems such as resin burrs in resin molding press machines such as injection molding or transfer molding, and deterioration of molding accuracy in metal press molding machines. There is.

[0004]

The problem to be solved is that in the resin molding press using the conventional method, resin burrs are generated in the molded product, and in the metal press molding machine, the molding accuracy deteriorates. The point is to do.

[0005]

In order to solve the above-mentioned problems, according to the present invention, an electric motor for rotatably mounting a nut portion corresponding to a screw portion provided on each column and rotating each nut portion is provided. Use the electric press machine that has each column.

[0006]

Embodiment 1 FIG. 1 shows an embodiment of the pressing device according to the present invention. Direct drive servo motor 1 for electric motor
1, is used. The lower bolster 3 is fitted with a plurality of columns 2 having screw parts 17 on the outer periphery thereof and the lower ends thereof. The upper ends of the columns 2 are fitted to the upper bolster 4.
Between the upper and lower bolsters, the moving bolster 1 is supported by the screw portions 17 of the plurality of columns 2 via the nut 13 and the thrust bearing 16.

The direct drive servomotor 11 is mounted on the nut 13 and the outer peripheral portion so as to rotate the nut 13. Reference numeral 14 is a stator, 15 is a rotor, and 12 is a casing. Upper bolster 4 and moving bolster 1,
Upper and lower molds 5, 6 for molding are respectively mounted between them.

Further, each of the plurality of columns 2 is equipped with a sensor 12 for electrically detecting the strain of the column, for example, a strain gauge, an optical displacement meter or the like. A signal from the sensor 12 is sent to a control circuit (not shown) of the direct drive servomotor 11 and fed back to the movement of the direct drive servomotor 11.

Next, the operation of the press machine according to the present invention will be described. Between the lower mold 6 and the upper mold 5, a metal plate 9, which is a workpiece, is placed in advance. By starting a plurality of direct drive servomotors 11, the nut 13,
Is rotated, and the movable bolster 1 is moved upward in the direction of the upper bolster 4 by fitting with the screw portion 17 of the column 2, and the abutment of the upper die 5, the lower die 6, and the die clamping. To do.

At this time, the driving force of the direct drive servomotor 11, the strain of the column 2, the sensor 12,
It is possible to suppress the variation of the press pressure to the minimum because it is detected by and the feedback control is performed to each predetermined value.

[0011]

EFFECTS OF THE INVENTION By using the pressing device according to the present invention, it is possible to suppress the generation of resin burrs in the resin molding press machine and to improve the molding accuracy in the metal press molding machine. Can be seen.

[Brief description of drawings]

FIG. 1 is a press device according to the present invention.

FIG. 2 is a detailed view of a screw portion of the pressing device according to the present invention.

FIG. 3 is a pressing device according to a conventional method.

[Figure 4]

[Explanation of symbols]

 1, moving bolster 2, column 3, lower bolster 4, upper bolster 5, upper mold 6, lower mold 7, electric motor 8, screw 9, metal plate 10, nut part 11, direct drive servomotor 12, casing 13, Nut 14, stator 15, rotor 16, thrust bearing 17, screw part

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[Procedure amendment]

[Submission date] November 11, 1993

[Procedure Amendment 2]

[Document name to be amended] Statement

[Name of item to be corrected] Fig. 4

[Correction method] Delete

Claims (1)

[Claims] 1. In a press device having two or more columns, a nut portion corresponding to a screw portion provided in each column is rotatably mounted on a moving bolster, and an electric motor for rotating each nut portion is provided. An electric press device characterized by having it for each column.