JPH0820053A - Injection apparatus of thermosetting resin - Google Patents

Abstract

PURPOSE:To provide the object injection apparatus capable of easily discharging all of the residual resin in a heating cylinder when an injection cycle is interrupted or molding work is completed. CONSTITUTION:This injection apparatus is constituted of a heating cylinder 1, a detachable nozzle 2 provided to the front end opening of the heating cylinder 1, a plunger 5b movable in the heating cylinder 1, a heater 3 heating the front part of the heating cylinder 1 and a cooler 4 cooling the intermediate part of the heating cylinder 1. Therefore, all of the residual resin in the heating cylinder can be easily discharged only by a simple operation detaching the nozzle 2 from the heating cylinder 1 to allow the plunger 5b to advance and a deficiency such s non-filling caused by the remaining of the resin can be avoided to stably perform injection molding.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an injection device for plasticizing a thermosetting resin and injecting it into a mold.

[0002]

2. Description of the Related Art Conventionally, a screw-in-line type injection device is mainly used for injection molding of thermosetting resin.
This injection device includes a heating cylinder having a nozzle at its tip, a screw rotatably arranged in the cylinder,
It is composed of a power source for rotating the screw, a hopper for supplying the molding material into the cylinder, and a heater for heating the molding material in the heating cylinder. It is plasticized by this and it is pressure-fed to the nozzle side by the rotation of the screw to perform the desired injection.

[0003]

When a thermosetting resin is molded by the above-mentioned screw in-line type injection device, when the injection cycle is interrupted due to trouble or the like, the molten resin in the heating cylinder is hardened together with the screw. Then, there is a problem that the subsequent injection cannot be performed. To solve this, disassemble the heating cylinder, pull out the screw,
The hardened resin adhering to the inside of the cylinder and the screw must be removed, and the cleaning operation requires a considerable amount of labor and time.

Further, although it is necessary to discharge all the resin in the cylinder at the end of the molding work, it is difficult to remove all the resin unless the cylinder is disassembled as described above, and when the injection is restarted, this There is a problem that the residual resin (cured product) is clogged in the nozzle or the gate of the mold and causes defects such as unfilling.

The present invention has been made in view of the above problems, and an object thereof is to provide a thermosetting resin which can easily discharge all the residual resin in the heating cylinder when the injection cycle is interrupted or when the molding operation is completed. It is to provide an injection device.

[0006]

In order to achieve the above object, the invention according to claim 1 has a heating cylinder having a tablet insertion port, a removable nozzle provided in a front end opening of the heating cylinder, and a heating cylinder inside. A plunger movable from a rear position of the charging port to a front end opening position, heating means provided in the front part of the heating cylinder, and cooling means provided between the charging port and the heating means of the heating cylinder. It is characterized by that. The invention of claim 2 is
The injection device according to claim 1 is characterized by comprising a tablet supply means for supplying a tablet to a charging port of the heating cylinder.

[0007]

In the injection device according to the first and second aspects of the present invention, the thermosetting resin tablet is charged into the heating cylinder through the charging port, and is pressed and moved by the plunger to move the plurality of tablets in the heating cylinder. Can be placed in The tablet located in the front part of the heating cylinder is plasticized by the heating means, and the tablet behind it is cooled by the cooling means to maintain the solid state, so that the plunger is advanced to press the last solid tablet. For example, the molten resin in the front portion can be pressed through the tablet and injected into the mold.

If the nozzle is removed from the heating cylinder after the molding work is completed and the plunger is further advanced,
The molten resin remaining in the heating cylinder and the tablet in the solid state can be discharged from the front end opening of the heating cylinder. Further, even when the injection cycle is interrupted due to a trouble or the like, the residual resin in the heating cylinder can be discharged by the same procedure as above.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a horizontal injection molding machine to which the present invention is applied.

In the figure, 1 is a heating cylinder, 2 is a nozzle, 3 is a heater, 4 is a cooler, 5 is an injection cylinder, 6
Is a slide base, 7 is a slide guide, 8 is a tablet feeder, 9 is a fixed plate, 10 is a movable plate, 11 is a mold, 1
2 tie bars, 13 is a mold clamping cylinder, and 14 is a bed.

As shown also in FIG. 2, the heating cylinder 1 has a cylindrical shape, and the tablet T is taken in a predetermined direction on the rear side surface, more specifically, in a direction in which the center line of the tablet T is parallel to the heating cylinder 1. It has a charging port 1a.

The tablet T is made by placing a powder of thermosetting resin such as epoxy, unsaturated polyester, phenol, diallyl phthalate in a mold and pressurizing it to solidify it into a cylindrical shape. It has a slightly smaller diameter than the inner diameter of the heating cylinder 1. Specifically, the diameter of the tablet T is about 9.8 to 65 mm, and the difference between the inner diameter of the heating cylinder 1 and the diameter of the tablet T is 0.5 mm or less.

The nozzle 2 has a sharpened shape, and its flange portion is detachably attached to the front end surface of the heating cylinder 1 via a bolt or the like.

The heater 3 has an inlet / outlet and an annular flow path 3a and is fitted around the front portion of the heating cylinder 1. Oil heated by a heating source (not shown) is fed into the heater 3 to maintain the front portion of the heating cylinder 1 at a high temperature suitable for plasticizing the tablet T.

The cooler 4 is provided with an inlet / outlet and an annular flow path 4a, and is fitted around the middle portion of the heating cylinder 2, that is, between the inlet 1a and the heater 3. Water cooled by a cooling source (not shown) is sent to the cooler 4 to keep the intermediate portion of the heating cylinder 1 at a low temperature at which the tablet T is not plasticized.

The injection cylinder 5 is provided with a plunger 5b at the front end of the shaft rod of a piston 5a, and is coaxially connected to the rear end of the heating cylinder 1 via a joint 5c. Plunger 5
In the standby state shown in FIG. 2, b is the inlet 1 in the heating cylinder 1.
It is located behind a, moves forward in the heating cylinder 1 by the operation of the piston 5a, and can slightly project from the front end opening of the heating cylinder 1 with maximum forward movement.

The slide base 6 supports the heating cylinder 1, the injection cylinder 5 and the parts feeder 8 and reciprocates on the slide guide 7 toward the fixed plate 9 by a power source (not shown).

The tablet feeder 8 is composed of a parts feeder and the like, accommodates a large number of tablets T, aligns them in a predetermined direction, and feeds them one by one to the charging port 1a of the heating cylinder 1 through the chute 8a.

The fixed platen 9, movable platen 10, mold 11, tie bar 12 and mold clamping cylinder 13 are the same as those of the conventional horizontal injection molding machine, and therefore their description is omitted here.

The operation of the above-mentioned injection molding machine will be described below with reference to FIGS. 2 to 5, taking a tablet made of epoxy resin as an example.

First, with the plunger 5b in the standby position, as shown in FIG. 2, the tablet T is loaded from the tablet feeder 8 into the heating cylinder 1. After the tablet is loaded, the plunger 5b is moved forward from the standby position, and the tablet T at the loading port position is pressed and moved to the nozzle vicinity position.

Then, the plunger 5b is retracted to the standby position, and the tablet T is re-inserted here to re-enter the plunger 5b.
b is moved forward to bring the tablet T into contact with the first tablet T, and this procedure is repeated to obtain a plurality of tablets T.
Are arranged in the heating cylinder 1 (see FIG. 3).

In the above tablet charging process, the front portion of the heating cylinder 1 is heated to a temperature suitable for plasticizing the epoxy resin by supplying heating oil to the heater 3, for example, 90 ° C. or higher 130
Since the temperature is maintained at a high temperature of less than 0 ° C, the tablet T pushed into the same portion immediately starts plasticizing and melts. Incidentally, the amount of resin melted here can be set in advance by the inner diameter of the heating cylinder 1, the size of the region that can be heated by the heater 3, and the like.

On the other hand, the front part of the heating cylinder 1 is provided with a cooler 4
Since the epoxy resin is kept at a temperature at which the epoxy resin is not plasticized by supplying cooling water to the
The tablet T located at the same site maintains a solid state without being plasticized.

When the melting of the resin is completed, specifically, several seconds to several tens of seconds after the completion of charging of the tablet T, the slide base 6 is advanced to bring the nozzle 2 into pressure contact with the sprue bush of the movable platen 9, and the plunger 5b is here. And push the last solid tablet T to move the tablet T
The molten resin Pm in the front portion is pressurized via and is injected into the mold (see FIG. 4). By the way, the injection amount can be controlled by the forward stroke of the plunger 5b.

In the above injection process, the molten resin Pm in the front portion tends to move rearward from the gap between the heating cylinder 1 and the tablet T in the solid state by the injection pressure, but the molten resin Pm is cooled by the cooler 4. As soon as it enters the possible area, it is solidified and does not flow into the plunger 5b and the rear portion thereof. Nevertheless, if there is a risk that the molten resin Pm will flow into the plunger 5b side, the area that can be cooled by the cooler 4 is increased, or the number of solid-state tablets T is increased to increase the heating area and the plunger 5b. The distance should be long.

Further, since the molten resin Pm in the front portion is pressurized and injected through the solid tablet T, even when a hard filler or the like is contained in the epoxy resin, the filler affects the injection conditions. Never give.

After the molding work is completed, the slide base 6
To the standby position, where the nozzle 2 is removed from the heating cylinder 1, and the plunger 5b is further advanced to move the molten resin Pm remaining in the heating cylinder 1 and the tablet T in the solid state from the front end opening of the heating cylinder 1. Discharge (see FIG. 5).

In the above-mentioned discharging process, the plunger 5b presses the last solid tablet T to melt the molten resin Pm.
Is being discharged, the molten resin P is
m does not adhere, and since the molten resin can be drawn and discharged with the tablet in the solid state, the molten resin Pm does not remain in the heating cylinder 1.

When the injection cycle is interrupted due to a trouble or the like, the nozzle 2 is removed from the heating cylinder 1 and the plunger 5b is advanced to remove the resin remaining in the heating cylinder 1 in the same manner as described above. Discharge from the front end opening. At this time as well, regardless of the state of the resin in the heating cylinder 1, the resin remaining in the heating cylinder 1 can be exhausted completely by the forward movement of the plunger 5b.

As described above, in the apparatus of the above-described embodiment, the molten resin in the front portion can be pressed by the forward movement of the plunger 5b through the solid-state tablet T at the rearmost end to be injected into the mold, as well as the heating cylinder. By the simple operation of removing the nozzle 2 from 1 and advancing the plunger 5b, all the residual resin in the heating cylinder 1 can be easily discharged at the end of the molding operation or at the time of interrupting the injection cycle. The desired injection and molding can be stably carried out while avoiding such defects as unfilled.

In the above embodiment, the nozzle 2 is attached to the front end of the heating cylinder 1 via a bolt or the like. However, if the attachment / detachment of the nozzle can be performed with one touch, the nozzle can be removed when the material is discharged. The work can be simplified.

For example, as shown in FIG. 6A, an arm 21a is extended to a part of the nozzle 21, the arm 21a is rotatably attached to the front end of the heating cylinder 1 via a pin 21b, and the nozzle is also attached. If a clamp 22 for holding 21 in a closed state is rotatably attached to the front end of the heating cylinder 1 via a pin 22a, the holding of the nozzle 21 by the clamp 22 is released as shown in FIG.
The nozzle 21 can be withdrawn upward and removed from the heating cylinder 1. If the rotation of the nozzle 21 and the clamp 22 is performed by a power source such as a motor, the nozzle 2
1 can be removed automatically.

Further, the heater and cooler in the embodiment may be integrated with the heating cylinder, and the heater may be an electric heater.

[0035]

As described above in detail, according to the inventions of claims 1 and 2, the molten resin in the front portion is pressurized by the forward movement of the plunger through the solid tablet at the rearmost end and injected into the mold. Of course, it is possible to easily discharge all the residual resin in the heating cylinder at the end of the molding operation or when the injection cycle is interrupted by a simple operation of removing the nozzle from the heating cylinder and advancing the plunger.
It is possible to avoid defects such as non-filling caused by residual resin and to stably perform desired injection and molding.

[Brief description of drawings]

FIG. 1 is a side view of a horizontal injection molding machine to which the present invention is applied.

FIG. 2 is an internal mechanism diagram of the injection device.

FIG. 3 is an operation explanatory view of the injection device.

FIG. 4 is an operation explanatory view of the injection device.

FIG. 5 is an operation explanatory view of the injection device.

FIG. 6 is a view showing another mounting structure of the nozzle.

[Explanation of symbols]

1 ... Heating cylinder, 2 ... Nozzle, 3 ... Heater, 4 ... Cooler, 5 ... Injection cylinder, 5b ... Plunger, 8 ... Tablet feeder, T ... Tablet, Pm ... Molten resin, 21 ...
Nozzle, 22 ... Clamp.

Claims (2)

[Claims] 1. A heating cylinder having a tablet charging port, a removable nozzle provided in a front end opening of the heating cylinder, a plunger movable in the heating cylinder from a rear position of the charging port to a front end opening position, and a heating cylinder. An injection device for thermosetting resin, comprising: a heating means provided in a front part of the heating means; and a cooling means provided between an input port of the heating cylinder and the heating means. 2. The thermosetting resin injection device according to claim 1, further comprising a tablet supply means for supplying the tablet to the inlet of the heating cylinder.