JPS5929414B2 - plastic molding equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a mold clamping device for a plastic molding machine.

Conventionally, so-called multi-stage injection molding machines, in which a single molding machine is equipped with a plurality of molds, have been used for the purpose of increasing productivity.

Looking back at the technological progress of multi-stage injection molding machines, (1) The prototype was an injection molding machine that had multiple mold clamping devices for one injection device and consisted of upper and lower sets of molds that corresponded to the clamping devices. becomes.

However, this requires complicated equipment, insert work,
For reasons such as not having enough space for the extraction process (
2) The injection molding machine was improved to have one injection device, one mold clamping device, and one upper mold, and consisted of a plurality of lower molds fixed to a slide table and a turntable.

With this type, it is difficult to keep the stop position accuracy of the slide table or turntable within the allowable accuracy of the mold combination, and it is easy to cause mold galling, poor molded product accuracy, mold closing and mold opening. Since the entire table moves during operation, the molds in the take-out station and insert station also move at the same time, making it impossible to perform take-out or insert operations.

In order to improve the accuracy of mold combinations, (3) one injection device, one mold clamping device, one slide table or turntable, and multiple sets of upper and lower molds with the lower mold fixed to the slide table, and the necessary stations. An injection molding machine configured with a mold opening device has been devised, but there are problems such as the need for an extra mold opening device, insufficient space for ejecting and inserting operations, and slow operation. has.

In addition, in order to prevent the slide table and turntable from moving in the mold clamping direction, there is a known method in which the upper mold and the entire injection device are configured to be movable in the mold clamping direction in step 2, but this increases the complexity of the device. However, it has the drawbacks of slow operation and high production costs.

As mentioned above, various types of conventionally known multi-stage injection molding machines are known, but each of them has drawbacks.

What these conventional examples have in common is that they are based on the idea that the mold must be accurately and firmly fastened during molding.

The present invention is based on the above concept and provides an injection molding apparatus that greatly improves productivity and equipment manufacturing costs.

This will be explained below using examples.

Fig. 1 is an overall perspective view showing an embodiment of the present invention, Figs. 2 and 3 are partial sectional views of Fig. 1, Fig. 2 shows the mold open state, and Fig. 3 shows the mold clamping state. Indicates the status of

A lower stationary platen 2 fixed on a bed 1 of the molding machine is connected to an upper stationary platen 1 by tie bars 3, 3'.

Rail frames 4 fixed to the bed 1 are arranged in two rows passing between tie bars 3 and 3', and support round bar-shaped rails 5, 5'.

Slide bearings 6, 6', which slide smoothly on the rails 5, 5', are fixed to a slide bed 7 constituting the table.

The slide bed 7 has a frame shape and has a guide shaft 8 at its edge.

As shown in FIG. 2, a hydraulic cylinder 9 is provided on the rear surface of the lower fixed platen 2 to attach the rails, and a piston 10 passes through a through hole 11 provided in the lower fixed platen 2, and connects the pair of rails 5, It is facing between 5' and 5'.

A movable platen 12 is fixed to the tip of the piston 10, and the movable platen 12 faces a hole in the frame of the slide bed 7.

A hydraulic cylinder 13 is provided on the movable platen 12, and a mold fixing piece 14 is provided at the tip thereof.

The lower molds 15 and 15' have guide shafts 8 corresponding to the guide shafts 8.
The through hole 16 is fitted with a clearance in the radial direction of the
A dovetail groove 17 having a clearance is provided corresponding to the mold fixing piece 14.

The upper mold 18 is attached to the upper fixed platen 2.

As shown in FIG. 1, a hydraulic cylinder 19 fixed to the bed 1 drives the slide table 7.
The tip of the piston of the hydraulic cylinder 19 is connected to the slide table 7.

In this mold clamping device, as shown in Fig. 2,
The lower mold 15 is lifted by allowing pressure oil to flow into the hole 9a of the hydraulic cylinder 9.

When the guide pin 20 of the upper mold and the guide bush 21 of the lower mold touch each other and you try to lift it further, the upper and lower molds are automatically aligned accurately within the clearance between the guide pin 8 and the hole 16. will be carried out.

Further, by flowing pressure oil into the hole 9a of the hydraulic cylinder 9, the lower mold 15 and the upper mold 18 are brought into contact, and a mold clamping force is generated between them in accordance with the product of the inner diameter area of the hydraulic cylinder and the hydraulic pressure.

Thereafter, molding is performed by injecting resin from a nozzle 22 shown in FIG.

Figure 3 shows the mold closed state at the molding station. Immediately before moving to the mold opening, the hydraulic cylinder 13 provided on the movable platen 12 is activated, the mold fixing piece 14 and the dovetail retaining part engage, and the lower The mold 15 and the movable platen 12 are fixed.

Thereafter, by pouring pressure oil through the hole 9b of the hydraulic cylinder 9, the mold is opened by overcoming the mold release resistance.

When the mold opening is completed, the supply of hydraulic pressure to the hole 9b of the cylinder 9 and the operation of the cylinder 13 are stopped.

After the mold opening is completed, the hydraulic cylinder 19 shown in FIG. 1 is operated to transport the lower mold 15' to the mold clamping station and the lower mold 15 to the unloading station.

The lower die 15 is transferred to a position where the protruding cylinder 24 and the sensor coincide.

At this time, the stopper 23 and the ear portion 25 of the lower mold face each other with a slight gap.

By actuating the ejection cylinder 24, the ejector plate 26 shown in FIG. 2 moves upward and ejection is performed.

In the case of a molded product with high mold release resistance, the lower mold is lifted by the ejection operation, but the lower mold 15 is fixed by the engagement of the stopper 23 with the ear portion 26 of the lower mold 15.

The lower mold 15 performs mold closing and mold opening operations in the same manner as the lower mold 15 described above.

Molding is performed by sequentially repeating the above operations.

Although the above embodiment describes a slide system, it can also be easily applied to a rotary one-way system by arranging the rails in an annular manner.

As described above, according to the plastic molding apparatus of the present invention,
The lower mold is provided to engage and slide on the guide shaft, and the mold is equipped with a guide pin and a guide bush for more accurate positioning, and the lower mold is slid on the table in multiple stages. By arranging multiple lower molds for one surface of the upper mold, mold manufacturing costs are reduced, and when closing and opening the mold, it is possible to remove parts other than the mold during molding. It has the advantage that the mold such as the station remains stationary, and operations such as ejection, ejection, and insertion can be performed quickly, resulting in high productivity.

Since it is easy to attach and detach, it has the advantage that it becomes possible to perform processing in which the lower die is shared with other molding machines and presses.

[Brief explanation of the drawing]

FIG. 1 is an overall perspective view of a plastic molding apparatus showing one embodiment of the present invention, and FIGS. 2 and 3 are partial sectional views of FIG. 1. 1...Bed, 5,5'...Rail,
7...Sliding bed (table), 8...
... Guide shaft, 9 ... Hydraulic cylinder, 12
...Movable platen, 13...Hydraulic cylinder, 14...Mold fixing piece, 15, 15'...
... lower mold, 16 ... hole, 17 ... dovetail groove, 18 ... upper mold.

Claims (1)

[Claims] 1 A rail provided on the base, one upper mold provided on a fixed plate fixed to the base, and a plurality of guide shafts provided slidably on the rail and having axes in the mold closing direction. a table that is slidable on the guide shaft, and has a through hole that forms a clearance in the radial direction with respect to the guide shaft for positioning, and that can be separated from the table and slid in the mold closing direction. and a plurality of lower molds that constitute a mold from the upper mold, and the lower molds transported to a position opposite to the upper mold by the movement of the table on the table. The upper mold and the lower mold are comprised of a mold clamping device that slides along a guide shaft, and a guide pin that engages when the upper mold and the lower mold are positioned within a predetermined distance in order to accurately position each other. A plastic mold with a guide bushing.