JPH0614995Y2 - Liquid molding material injection machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a liquid molding material injection and injection device used in injection molding of liquid silicone rubber or the like.

[Technical background of the invention and its problems] Conventionally, injection injection of liquid silicone rubber into a mold has been performed as shown in FIG. Although FIG. 3 shows an example of injection molding of a silicone rubber roller having a shaft at the center, in this figure, the molding die 2 supported around the shaft 1 is provided on the lid 3 a of the pressure injection device 3. It is fluid-tightly and detachably attached to the mold mounting base 4. The mold mounting base 4 is provided with a liquid silicone rubber passage 6 which communicates with the pressurizing device 3 through valves 5 and 5 and communicates with a space having an annular cross section between the inner periphery of the mold 2 and the shaft 1. ing. The pressurizing device 3 has a pressurizing piston 7, and when the piston is pushed up, the liquid silicone rubber 8 in the pressurizing device 3 is injected and injected into the molding die 2 via the passage 6.

In the conventional injection and injection device of this type, the cylinder containing the piston 7 for applying the injection pressure also serves as the liquid silicone rubber container of the pressurizing device 3, so that the storage capacity of the liquid silicone rubber cannot be increased. , It was often necessary to replenish it to the pressurizing device. Further, even if the storage capacity can be increased, it is not possible to provide an agitator inside because it is a pressurizing device, and it is not possible to keep the material in which the main material and the curing material are mixed in an uncured state for a long time. Have difficulty.

[Object of the Invention] The present invention has been made in view of the above circumstances, and it is possible to store a large amount of an injection molding material in which a main material and a curing material are mixed in a storage tank in an uncured state. Provided is a liquid molding material injection and injection device capable of automatically performing quantitative extraction from the storage tank and injection and injection into a molding die.

[Summary of the Invention] A liquid molding material injection and injection device of the present invention includes a molding material storage tank, a pressure cylinder, a metering injection cylinder driven by the pressure cylinder, and a discharge port of the metering injection cylinder. An automatic switching valve for switching between a position for communicating with the inside and a position for communicating with the bottom surface of the molding material storage tank in conjunction with the operation of the pressurizing cylinder.

In the liquid molding material injection / injection device of the present invention having the above structure, the automatic switching valve causes the discharge port of the metering injection cylinder to communicate with the bottom of the molding material storage tank when the piston of the pressurizing cylinder moves backward, and to communicate with the nozzle when moving forward. To be switched automatically. Therefore, the metering injection cylinder sucks and stores a predetermined amount of molding material from the storage tank when the piston moves backward, and the metering and stored predetermined amount of molding material into the molding die through the nozzle when moving forward. Injection injection.

[Embodiment of the Invention] FIG. 1 is a front view of an embodiment of the present invention. In this figure, a molding material storage tank 12 is installed on one pedestal 11, a pressure injection device 14 is attached on the other pedestal 13, and a molding die is attached to an end of the pedestal 13 adjacent to the pedestal 11. A mount 15 is installed.

FIG. 2 is a sectional view schematically showing the embodiment. The pressurizing device 14 includes a pressurizing cylinder 16 and the pressurizing cylinder 1.
Piston 17a driven by six pistons 16a
A metering injection cylinder 17 having the above and a nozzle 19 communicating with the discharge port of the metering injection cylinder 17 through an automatic switching valve 18 and opening on the upper surface of the mold mounting base 15 are provided. In addition, a stirring blade 21 rotated by a motor 20 attached to the upper part of the tank is installed in the molding material storage tank 12, and an automatic switching valve 18 is provided at the bottom of the tank 12 by a conduit 23 via a manual stop valve 22. Is in communication with.

The pressurizing cylinder 16 and the automatic switching valve 18 are pneumatically operated. The automatic switching valve 18 makes the pipe line 23 communicate with the metering injection cylinder 17 when the piston 16a of the pressurizing cylinder 16 retreats, and the piston 16a moves forward. Sometimes, the metering injection cylinder 17 and the nozzle 19 are made to communicate with each other. This interlocking relationship can be easily realized by operating the solenoid valve using a limit switch or the like. In the figure, 24 is a molding method, and 25 is a molding material storage tank 12.
The vacuum pump for evacuating the inside is shown.

The injection injection device of the present invention having the above structure operates as follows.
First, the molding material containing the main material and the hardening material is charged into the molding material storage tank 12, the stirring blades 21 are rotated to mix the materials, and then the vacuum pump 25 is used to remove bubbles in the material. Then, the molding material storage tank 12 is evacuated to prepare the material. The stop valve 22 is opened at the start of injection molding.

Next, the mold 24 is attached to the mold mount 15.
Next, the piston 16 of the pressure cylinder 16 of the pressure device 14
a is retracted. As a result, the piston 17a of the metering injection cylinder 17 also retracts. At this time, the automatic switching valve 1
Reference numeral 8 makes the bottom of the storage tank 12 communicate with the metering injection cylinder 17 via a pipe line 23.
The molding material flows in from. When the piston 17a retracts by a predetermined distance, a predetermined amount of molding material is measured and stored in the metering injection cylinder 17.

Here, the urging direction of the pressure cylinder 16 is set to the piston 16a.
Switch to the forward direction. At the same time, the automatic switching valve 18
Is a position where the metering and injection cylinder 17 and the nozzle 19 communicate with each other. After that, piston 16a, piston 1
A predetermined amount of the molding material, which has been measured and stored in the metering injection cylinder 17 as the 7a advances, passes through the nozzle 19 to the molding die 2
4 will be injected and injected.

Thereafter, the above operation is repeated while exchanging the molding die or taking out the molded body in the die. The molding material in which the main material and the hardening material are mixed is stored in the storage tank 12, and the injection is completed within the pot life of the molding material (the time during which the molding material is held in the storage container for injection molding). You can do it like this.

[Advantages of the Invention] As is apparent from the above, in the liquid molding material injection / injection device of the present invention, it is possible to automate the operation of measuring and injecting the molding material into the molding die during injection molding. Labor saving can be achieved. Moreover, since it is not necessary to mix them immediately before the start of injection injection, the structure of the device can be simplified.

[Brief description of drawings]

FIG. 1 is a front view of an embodiment of the present invention, FIG. 2 is a schematic cross-sectional view of a main part thereof, and FIG. 3 is a cross-sectional view of an example of a conventional injection injection device. 12 ... Molding material storage tank, 14 ... Pressurizing device, 15
...... Molding die mount, 16 ...... Pressurizing cylinder, 16a, 1
7a ... Piston, 18 ... Automatic switching valve, 19 ... Nozzle, 21 stirring blade, 24 ... Molding die

Claims (1)

[Scope of utility model registration request] 1. A molding material storage tank, a pressure cylinder,
A metering injection cylinder driven by this pressurizing cylinder, a position where the discharge port of this metering injection cylinder is communicated with the molding die, and a position where it is communicated with the bottom surface of the molding material storage tank are linked to the operation of the pressurizing cylinder. A liquid molding material injection / injection device, comprising: