JPS61242794A - Control device for pressurizing press - Google Patents

Abstract

PURPOSE:To simplify an installation and to execute smoothly control by providing a speed pattern generator which commands the speed of a motor at a set speed pattern, a speed detector, a circuit which amplifies differentially the outputs of both and output limiting circuit which limits the output from the circuit at a set value. CONSTITUTION:A screw bar 36, a cylinder 41 and a moving table 4 pressurize a moving die 6. A command to start a transfer 48 by connecting a clutch 44 and driving the motor 42 is emitted from a control device 61. The command for the initial speed and the speed corresponding to the set pattern is kept emitted from the speed pattern generator 53 connected to an amplifier 55 side. The loop consisting of the generator 53, a differential device 54, the amplifier 55, a power amplifier 60, the motor 42 and a speed power generator 42a constitutes a motor speed control system. The speed of the transfer 48 increases at the speed corresponding to the speed command. The motor current increases according to the packing of a resin into a molding part. The current value does not increase anymore when the set value of the pressure setter 56 is attained. The resin is pressure-molded under the torque corresponding to the current value.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] This invention relates to an improvement of a control device for a pressure press.

[Prior art]

FIG. 2 is a configuration diagram of a conventional hydraulically driven resin molding press device, in which (1) shows a rectangular or square base;
(2) is the four pillars erected at the corners of this base (1), (3) is the upper table fixed to the top of this pillar (2), and (4) is moved along the pillar (2). The moving table (5) is J:fg! Fixed to the I table (3),
The upper mold (6) is held at a set temperature, and the movable mold (6) is fixed to a moving table (4) and held at a set temperature.
7) is a moving cylinder that moves the moving table (4) at high speed with low pressure, and (8) is the upper mold (5) and the moving mold (6).
High pressure and low speed pressure welding cylinder (9)
), αQ is a pipe that supplies oil when the piston of the moving cylinder (7) is raised, Ql), 111 is a pipe that supplies oil when the piston of the moving cylinder (7) is lowered, and 4. Piping that supplies oil when raising the pressure cylinder (8), #, α・ is the pipe that supplies oil when lowering the pressure cylinder (8), αη, Qa, (19, E is an electric three-way valve , is the solenoid valve, O, Ca, rumor, and (sub) is the oil return piping.

4 is a low pressure, high flow hydraulic pump, @ is a high pressure, low flow hydraulic pump, (2) is an electric three-way valve qη, shout, α9゜■,
A control device that supplies power to and controls the solenoid valves Qυ hydraulic pumps (1) and (2) is the piping.

Conventional hydraulically driven resin molding equipment is configured as described above.For example, during molding, the movable mold (6) is raised and pressed against the fixed mold (5), so the hydraulic pressure is applied during the movement. Oil is supplied from the bong holder to the cylinder (7) via the pipe (9), the three-way valve αg, and the pipe αq, and the movable table (4) is raised at high speed. At this time, the piston of the pressure welding cylinder (8) is lifted by the moving table (4), and the oil is transferred to the piping ■, the solenoid valve (to), the electric three-way valve (g), and the piping α.
When the 0-movement mold (6), which is sucked into the lower part of the pressure cylinder (8) through ◆, contacts the upper mold (5), the previous position is detected by a detector (not shown), and the drive system The control device (2)
to switch from the moving cylinder (7) to the pressure cylinder (8). That is, high-pressure, low-flow oil is supplied through the hydraulic valve/gut pipe a, the three-way hydraulic valve, and the pipe α4.

Therefore, the piston moves at a low speed, and after the molds come into contact, the upper mold (5) and the movable mold (6) are pressed together under high pressure.

In this state, resin is injected into the interiors of both molds by a resin injection device≦ζ (not shown) and molded. When removing molded resin and inserting new resin.

When lowering the movable mold (6), the operation in reverse to the above-mentioned raising step is performed.

By the way, a moving cylinder (7) for moving the moving table (4) and a pressure welding cylinder (8) for pressurizing are both installed at the bottom of the moving table (4) and above the pace (1). When moving the moving table (4), the moving table (4) is driven by the piston of the moving cylinder (7), and the piston of the pressure cylinder (8) is also displaced in accordance with the movement of the moving table (4). 1 stroke.

That is, when pressurizing the upper mold (5) and the movable mold (7), the piston of the pressure cylinder (8) starts the pressurizing operation from a position where it has been largely displaced in advance.

[Problem that the invention seeks to solve]

Since the conventional pressure press control device is configured as described above, both the moving cylinder and the pressure cylinder, which require high precision, require large strokes, which not only increases the size of each cylinder, but also increases the size of each cylinder. The movable table will be pressed at different positions by the pressure cylinder and the movable cylinder, and at least one will be pressed at an offset position on the bottom of the movable table, so when the movable table is moved or pressurized, the movable table will be pressed at different positions. Not only is there a problem in that large friction occurs between the cylinder and the support, which causes wear on the support after long-term use, but also because the hydraulic cylinder that injects the resin, the moving cylinder, and the pressure cylinder are arranged horizontally. However, the device becomes larger in the horizontal direction, the installation space becomes larger, the hydraulic system becomes complicated, and there are problems in that oil leakage occurs.

This invention was made to eliminate these drawbacks, and provides a pressure press that can downsize the cylinder that requires high precision, improve reliability over the long term, and simplify the structure. It is intended to.

[Means for solving problems]

A pressure press control device according to the present invention includes a speed pattern generator that outputs a speed command signal according to a set speed pattern, a speed detector that is connected to an electric motor to detect speed, and an output of the speed pattern generator. A differential amplifier circuit that differentially amplifies the output of the speed detector, and if the output from this differential amplifier circuit is smaller than a preset value, outputs the output from the differential amplifier circuit, and The apparatus is equipped with an output limiting means that outputs the preset value when the value is greater than or equal to the set value.

[Function] The pressure press control device according to the present invention causes the output limiting means to output an output based on the difference signal when the difference between the speed command signal and the speed detector is smaller than a preset value. , if the value is less than a preset value, the preset value is outputted by the output limiting means.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to FIG.

In the figure, (1a) is provided integrally with the pace (1).

A bearing member having a bearing part (1b) at a position spaced apart from the pace +1), (to) a reducer having a built-in reduction gear, (to)
is a screw shaft connected to this reducer (to) via a coupling (to), and a pair of radial bearings (to)
It is supported by the bearing member (la) through the threaded part (
36a). cll is a pair of radial bearings (
A pair of retaining nuts (7) are threaded onto the threaded part (36a) of the screw shaft (7) and a cylindrical housing (40a) surrounding the threaded part (36a). ) and a seven-rank portion (40b) provided at the upper end of the housing (40a). However, 7
A cylinder coupled to the rank portion (40b) has a detent shaft (4-) that engages with an engagement hole (4L) formed in the movable table (4) so as to be relatively movable in the axial direction, and a detent shaft (4-) that is connected to the movable table (4). ) is M.

The mackerel is an electric motor that transmits power to the input side of the reducer via a clutch, and is placed parallel to the screw shaft. (42a) is a speed generator installed in this electric motor (A) and outputs a voltage proportional to the rotational speed of the electric motor; (42a) is a clutch connected to the other end of the electric motor (C); Reducer connected to clutch ■,
- is a screw shaft rotated by this reduction gear), -η is a nut that moves up and down according to the rotation of this screw shaft -, and the decoy is a movable mold (6) and a movable table (4).
Guide holes (6a) and (4b) formed perpendicularly to
It is a transfer that moves up and down inside and is fixed to the nut (b) above. - is a thrust bearing that receives the thrust force of the screw shaft ■, field is resin for molding, 63
) is a speed pattern generator (54) that issues a command value for the rotational speed of the motor mackerel according to each position of the moving table (4);
) is a differential device (55) which takes the difference between the signal of the speed pattern generator (53) and the signal of the speed generator (42 &>
) is an amplifier that amplifies the signal from the differential device (54);
(56) is a pressure setting device that sets the pressurizing torque of the transfer, (60) is a power amplifier that converts the output signal of the amplifier (55) or the voltage signal from the pressure setting device into electric energy, and (61) is the entire system. (62) is an amplifier (5) that performs sequence control, power supply, etc.
When the signal value from 5) is less than the set value of the pressure setting device (56), the signal from the amplifier (55) is sent directly to the power amplifier (
6o), and when the current limiter exceeds the value, the current limiter continues to send the signal value of the set value of the pressure setting device (56) to the power amplifier (60) regardless of the signal value of the amplifier (55).

In the device configured as above, first, when the clutch is connected and the clutch is released to drive the electric motor, the screw shaft is connected to the screw shaft through the reducer (to) and the coupling (to). rotates. Therefore, the nut (36a) engaged with the threaded portion (36a) moves upward and moves the moving table (4), that is, the moving mold (6) upward via the cylinder (6). The locking shaft (41a) of the cylinder @ sword is connected to the retaining hole (4) of the moving table (4).
4a), the nut (a) is prevented from rotating via the cylinder (rotation), and the screw thread shaft (
7) The nut ■, cylinder (6), moving table (4), and moving mold (6) move upward according to the rotation of 0. The moving mold (6) approaches the upper mold (5). When the electric motor is stopped at the position and the cylinder (6) is moved, the piston (41b) moves the moving mold (6) through the moving table (4).
) is pressurized.

Here, when the clutch is released and the clutch ■ is connected to drive the electric motor (6), the screw shaft () rotates through the reducer () and the screw shaft () rotates in response to this rotation. ) (471, The transfer moves upward 0 Therefore, the molding resin group above the transfer is injected between the upper mold (5) and the movable mold (6),
molded. That is, since both molds r5) and (6) have been heated in advance, the injected molding resin group will harden.

Here, we will discuss the transfer in detail. transfer) is initially at the lowest level. Control device (61)
When a command to start the transfer (c) is issued, the speed pattern generator (53) connected to the amplifier (55) side is activated.
) the initial speed command value is issued. Thereafter, the speed pattern generator (53) continues to issue speed command values according to the set pattern. A series of loops including a speed pattern generator (53), a differential (54), an amplifier (55), a power amplifier (60), a motor (42), and a speed generator (42a) performs motor speed control including so-called speed feedback. Show the system. It goes without saying that this control system can be replaced with a motor speed control system that does not include a feedback system such as an inverter. With the above configuration and operation, the transfer continues to rise at a speed according to the speed command, and as the molding part is filled with resin, the motor current increases, and the pressure setting device (56)
Once the set value of is reached, the current value will not increase any further.

It is pressurized with a torque corresponding to the current value.

After molding, if the transfer is lowered to the lowest position, the pressure in the cylinder (6) is released, and the screw end is reversely rotated by the electric motor, both molds (5) are removed.

(6) will be separated and the work will be completed.

[Effects of the Invention] As described above, according to the present invention, there are provided a speed pattern generator that outputs a speed command signal according to a set speed pattern, a speed detector that is connected to an electric motor to detect speed, and the speed pattern generator described above. A differential amplifier circuit differentially amplifies the output of the speed detector and the output of the speed detector, and if the output from the differential amplifier circuit is smaller than a preset value, the output from the differential amplifier circuit is output. However, since it is equipped with an output limiting means that outputs the preset value when the value exceeds the preset value, the cylinder can be made smaller, long-term reliability can be improved, and the structure is simple. Furthermore, it is possible to smoothly and automatically switch from speed control to torque control.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, and FIG. 2 is a block diagram of a conventional device. According to the figure, (7) is the screw shaft, the ring is the nut,
(53) is the speed pattern generator, (54) is the differential, (55) is the amplifier, (56)
is a pressure setting device, (61) is a control device, and (62) is a current limiter. Note that the same reference numerals in each figure indicate the same or corresponding parts.

Claims (1)

[Claims] A speed pattern generator that outputs a speed command signal according to a set speed pattern, a speed detector connected to the electric motor to detect speed, and differential amplification of the output of the speed pattern generator and the output of the speed detector. A differential amplifier circuit, and if the output from this differential amplifier circuit is smaller than a preset value, the output from the differential amplifier circuit is output, and if the output is greater than the preset value, the output is the preset value. A pressure press control device equipped with an output limiting means for outputting.