JPH074832B2 - Injection molding machine - Google Patents

Description

TECHNICAL FIELD The present invention relates to an injection molding machine including a plurality of mold clamping devices and an injection device on a machine base.

[Prior Art] An injection molding machine in which a plurality of mold clamping devices and a single injection device are provided on a machine base is already known. Such an injection molding machine has a long molding cycle and is used for injection molding such as foam molding in which most of the molding cycle is occupied by cooling time.

In the example shown in FIG. 4, two mold clamping devices 2 and 3 are placed on the machine base 1 so that the mold clamping devices 2 and 3 can be alternately accommodated.
The base injection device 4 is movably provided, and when one mold clamping device 2 is in the cooling step, injection can be performed to the other mold clamping device 3.

In the example shown in FIG. 5, one injection device 4 is provided at the center of the machine base for two mold clamping devices 2, 3 on the machine base 1, and
By means of a switchable nozzle device 7 having a pair of nozzles 5 and 6 provided between the mold 3 and the injection device 4, the time required for the resin material injected into the mold of one mold clamping device 2 to be cooled and solidified. In addition, the mold of the other mold clamping device 3 can be injection-filled.

[Problems to be Solved by the Invention] Therefore, although the injection molding machine is effective as a dedicated machine for injection molding of a molded product such as foam molding having a long cooling time,
In order to perform general molding such that the cooling time is shortened and the cycle is increased, the workability is poor and the cost is increased.

An object of the present invention is to provide an injection molding machine equipped with a plurality of mold clamping devices as described above, which can perform normal injection molding with a short cooling time and can also perform simultaneous molding of a plurality of resins. To provide a simple injection molding machine.

[Means for Solving the Problems] The features of the present invention according to the above object are that a plurality of sets of mold clamping devices and injection devices arranged in parallel on a machine base, and switching provided between both mold clamping devices and injection devices. A main body having a connecting resin passage therein, and a pair of nozzle attachments respectively located on both sides of the main body between the mold clamping device and the injection device. It is composed of a switching valve that connects or disconnects the communication resin passage and the resin passage on the nozzle attachment side, and a nozzle opening / closing valve provided in the tip portion of the nozzle attachment.

The nozzle opening / closing valve is a rotor reshutoff valve, and the switching valve is a pair of valve devices that individually open and close the communication resin passage.

[Operation] In the above configuration, by opening and closing the communication resin passage in the main body, injection molding by a plurality of sets of injection devices is performed individually or in a combined state, and in a state where both nozzle attachments are in communication, By the simultaneous operation of a pair of injection devices,
The injected resin merges in the switching device to the mold of one mold clamping device, and in the switching operation of the connecting resin path, the resin from one injection device alternates to the molds of both mold clamping devices. Injection filled.

[Embodiment] FIGS. 1 to 3 show an embodiment of the present invention, in which 11 is a machine base, and 12 and 13 are two sets of rigid mold clamping devices arranged in parallel on the machine base 11. , 14 and 15 are two sets of injection devices on the machine base 11 arranged in parallel for each mold clamping device 12 and 13.

A switching device 16 is provided between the mold clamping devices 12 and 13 and the injection devices 14 and 15 on the machine base so as to be movable back and forth and detachable. As shown in FIG. 3, this switching device 16 has a connecting resin passage 17 inside.
Having a horizontally long main body 18, a pair of nozzle attachments 19 and 20 provided at both ends of the main body 18, and a pair of switching valves 21 and 2 for opening and closing the communication resin passage 17 at both ends.
Nozzle opening / closing valves 23, 24 that are rotary shutoff valves that are opened and closed by cylinders 25, 26 are provided in the tip end portions of the nozzle attachments 19, 20.

The switching valves 21 and 22 are needle valves connected to the piston tips of hydraulic cylinders 27 and 28 provided outside the nozzle attachments 19 and 20, and open and close the open end of the communication resin passage 17 that communicates with the resin passage inside the attachment. It is supposed to do.

Reference numeral 29 is a hydraulically operated moving cylinder of the switching device 16. Although not shown in the drawing, the switching device 16 is provided with a heating or heat retaining means for preventing the resin from being cooled and solidified at the time of molding, or thermally decomposed by heating for a long time.

Next, the molding operation will be described.

After nozzle-attaching the injection devices 14 and 15 to the molds 12a and 13a of the mold clamping devices 12 and 13 via the nozzle attachments 19 and 20, the communication resin passage 17 is closed by the switching valves 21 and 22.
Also, by opening the nozzle opening / closing valves 23, 24, both injection devices 1
When the molten resin is injected from 4,15, the molten resin is injected from the nozzle attachments 19,20 into the molds 12a, 13 of the mold clamping devices 12,13.
It is injection-filled into a, and the molding by the respective injection devices 14 and 15 is individually performed therein.

Next, when alternately injecting into both molds 12a, 13a by one injection device 14, first the other injection device 15 is moved backward and separated from the nozzle attachment 20 to the gate of the nozzle attachment 20. Although not shown in the drawing, a sealed plug is provided to prevent leakage of the molten resin from the nozzle attachment. Further, the switching valve 22 is set to open and the nozzle opening / closing valve 24 is set to closed.

After such preparation, the switching valve 21 is used to
Close the nozzle nozzle opening / closing valve of the nozzle attachment 19
When 23 is opened and the molten resin is injected from the injection device 14, the molten resin is injected and filled into the mold 12a through the nozzle attachment 19.

After the injection is completed, the switching valve 21 and the nozzle opening / closing valve 23 on the nozzle attachment side are closed to measure the resin. After the measurement, the switching valve 21 is opened, the nozzle opening / closing valve 24 of the attachment 20 is further opened, and the molten resin is injected by the injection device 14.
Flows into the nozzle attachment 20 and is injected and filled into the mold 13a.

Therefore, by repeating the operations of the valves of both nozzle attachments 19 and 20, the alternate injection can be performed by the one injection device 14. Such molding can also be performed on other injection devices 15 under similar means.

Further, when molding is performed by joining two kinds of resins with both injection devices 14 and 15, only the switching valve 22 of the nozzle attachment 20 is opened and all the other valves are closed, and both of the valves are closed. Resin is measured in the injection devices 14 and 15.

By this measurement, the molten resin on the injection device 15 side is connected to the connecting resin path 17
After the weighing is completed, the switching valve 21
Open the nozzle opening / closing valve 23 on the mold 12a side, and simultaneously inject the molten resin by both injection devices 14 and 15, both resins are attached to the nozzle attachment 1 on the mold 12a side.
They merge in 9 and are injected and filled in the mold 12a.

By repeating such an injection operation, it is possible to perform the confluent molding of the two kinds of resin into the mold 12a.

When this merge molding is performed on the two molds 12a and 13a in combination, the above valve operation is performed on both nozzle attachments 19 and 20.
It may be done alternately in.

Although the mold clamping device of the above embodiment is rigid, the mold clamping device may be a horizontal mold clamping device that opens and closes the mold horizontally.

[Advantages of the Invention] Since the present invention is configured as described above, it has the following effects.

By simultaneously operating a plurality of sets of injection devices, the injection resins are merged in the switching device and injected into one mold,
An injection capacity and an injection rate obtained by summing up a plurality of sets of injection devices can be obtained, and when molding a large capacity, it is effective in shortening the measuring time and securing the injection capacity and the injection rate.

If the timing of the injection switching valve is devised in the molding operation of the merge molding, mixed color molding and sandwich molding can be performed.

The operation of using one injection device and multiple sets of mold clamping devices and alternately injecting into multiple molds by switching the switching device is effective in molding with a long cooling time, and at the time of failure occurrence or maintenance. The molding can be continued even if one of the injection devices is stopped due to the above reasons.

If you want to use them individually as a set of injection molding machines, you can do this by shutting off the connecting resin path with the switching valve in the switching device, and shortening the resin path from the injection part to the mold to retain the resin. When it is desired to reduce the amount of heat, it suffices to remove the switching device and perform molding. In this case, heating and heat retention of the switching device are unnecessary, which is advantageous in terms of energy saving.

[Brief description of drawings]

1 to 3 show an embodiment of an injection molding machine according to the present invention. FIG. 1 is a schematic plan view, FIG. 2 is a side view thereof, and FIG. 3 is a plan view of a switching device portion. Sectional views, FIG. 4 and FIG. 5 are schematic plan views of a conventional example. 11 …… Machine 12,13 …… Clamping device 14,15 …… Injection device 16 …… Switching device 17 …… Communicating resin path 18 …… Main body 19,20 …… Nozzle attachment 21,22 …… Switching valve 23 , 24 …… Nozzle on-off valve

Claims (3)

[Claims] 1. A plurality of sets of a mold clamping device and an injection device arranged in parallel on a machine base, and a switching device provided between the mold clamping device and the injection device, the switching device having an internal communication resin. A main body having a passage, a pair of nozzle attachments on both sides of the main body, each of which is located between the mold clamping device and the injection device, and the connecting resin passage and the resin passage on the nozzle attachment side. An injection molding machine comprising: a switching valve that connects or disconnects, and a nozzle opening / closing valve provided in a tip portion of a nozzle attachment. 2. The injection molding machine according to claim 1, wherein the nozzle opening / closing valve is a rotary shutoff valve. 3. The injection molding machine according to claim 1, wherein the switching valve comprises a pair of valve devices for individually opening and closing the communication resin passage.