JPS644504Y2 - - Google Patents

Description

[Detailed Description of the Invention] Technical Field The present invention relates to an improvement in an extrusion molding die for molding a desired product shape by discharging molten resin from a mold outlet.

BACKGROUND ART In general, in this type of mold, as shown in FIG. 1, molten resin is communicated via an adapter A from a cylinder (not shown) with a built-in screw to a mold body C from a receiving port 1. flow path 2
It is configured so that it is exclusively discharged from the mold outlet 3 through the mold outlet 3.

The operation of these molds is often temporarily stopped during production, and when this stop occurs, the heater built into the mold body is also temporarily shut off, but due to the heating of the mold body, adapter A The resin that remains near the breaker plate (not shown) and in the flow path 2 that communicates from the inlet 1 to the mold outlet 3 of the mold body becomes carbonized or deteriorates to the point where it becomes lumpy, as if foreign matter had been mixed in. . When the operation is restarted, the deteriorated resin flows out from the mold outlet 3 for a considerable period of time depending on the relative volume of the product and the retained resin, so even if it is formed into the desired shape, it is discarded. This will lead to a decrease in manufacturing efficiency.

In addition, when extruding a resin attachment b onto an expensive metal core material a such as stainless steel, as in the molding shown in Fig. 2, it is necessary to discard a long portion of the material to which deteriorated resin has adhered. The cost of materials increases considerably. In order to avoid waste of the metal core material a, even if the metal core material a is not moved and only the deteriorated resin is allowed to flow out so that it adheres to a certain area, the deteriorated resin will flow back inside the passage of the holder slit. Therefore, it is inevitable to discard the metal core material a to which the backflow resin has adhered.

In addition, conventionally, a stop valve was installed between the crosshead equipped with a core metal and a cap and the cylinder with a built-in screw to cut off the supply of compound from the cylinder side to the crosshead side, and an on-off valve was installed on the cylinder side of this stop valve. An extruder equipped with a compound discharge passage is known (Japanese Patent Laid-Open No. 57-15944).
issue).

In this extruder, a compound discharge path that is opened and closed by an on-off valve is branched from a communication hole through which resin is pumped by a screw, and the on-off valve itself selectively opens and closes the communication hole and the compound discharge path. Therefore, in addition to this on-off valve, a valve for stopping the compound from moving toward the crosshead must be installed at another position in the communication hole. Therefore, in such an extruder, it is unavoidable that deteriorated resin accumulates in the communication path of the crosshead, at least closer to the compound discharge path than the compound stop valve, and even if the resin accumulated in the mold body deteriorates, it is impossible to prevent the deterioration of the resin. It cannot be ejected out of the mold. Further, in this extruder, a compound stop valve and a compound discharge passage are provided on the side of the cylinder through which the resin is forcedly fed by a screw to the crosshead.
This is to allow the cylinder side to continue operating even if the compound stop valve stops the resin supply to the crosshead side, but this allows the compound to remain constant in the cylinder as the compound discharge path is opened. The back pressure that had been building up was reduced, and
Since this back pressure drop extends to the metering zone and compression zone of the cylinder, it is inevitable that a situation will arise in which the resin cannot be sufficiently kneaded by the screw. This poorly kneaded resin reduces the physical strength of the product, and also exposes unkneaded solid resin on the outer surface, damaging the appearance, so it should be discarded as a defective resin. I will have no choice but to do so.

DISCLOSURE OF THE INVENTION The present invention provides an extrusion mold configured to separately discharge deteriorated resin in order to improve the manufacturing efficiency of various extrusion molded products and to minimize waste of expensive materials such as metal core materials. ,With the goal.

That is, in the extrusion molding mold according to the present invention, the breaker plate is connected to the adapter provided in the resin flow path, and the mold body is connected to the mold body from the resin inlet to the mold outlet, and the resin such as the metal core material of the molding is connected to the mold body. A constant flow path for the resin that joins the holder slit through which the adhesion member is inserted is provided, and a branch flow path is formed by branching from the middle of the constant flow path to communicate with the resin discharge port, and at the branching point of these flow paths, It is constructed by installing a switching valve that selectively opens and closes each flow path.

Function This extrusion mold has a switching valve inside the mold body that selectively opens and closes the resin flow paths on the mold outlet side and the discharge port side, that is, one valve controls the mold outlet. It is equipped with a switching valve that closes the discharge port when opening the mold, and closes the mold outlet when opening the discharge port, and the switching valve is installed at the junction between the mold exit side and the discharge port side. At least, the deteriorated resin remaining in the mold body can be discharged out of the resin flow path without leaving any residue, and the internal pressure of the cylinder in which the resin is kneaded by the screw is not reduced, so it is sufficient. By obtaining sufficient back pressure and reducing the discharged resin without producing insufficiently kneaded resin, it becomes possible to perform good extrusion molding of the resin. Therefore, with this extrusion mold, if any defective products are produced when work is restarted, the number of defective products can be kept to a minimum.

Embodiment The following will be described with reference to FIGS. 3 to 6.

This mold has a resin inlet 1 in the main body C, and an adapter A having a resin injection path 4 communicating with the inlet 1 on the upper surface thereof and equipped with a breaker plate (not shown) is screwed and fixed. ing. Further, an intermediate plate c ₁ and an end plate c ₂ are integrally fixed to the main body C of this mold, and resin flow paths 2 and 2a are formed from the resin receiving port 1 to the intermediate plate c ₁ , and the flow path 2 , 2a is formed in the end plate _c2 .

The mold exit 3 is formed with an opening corresponding to the desired product shape, and the mold exit 3 is provided with holder slits 5a, 5b, 5c through which a resin adhering member such as a metal core material of the molding is inserted, and an end plate _c2. It is designed to meet at Further, the mold body C is provided with a flow path 7 which is branched from the middle of the flow path 2 to enable communication between the resin discharge port 6 and the receiving port 1 in a direction opposite to the mold outlet 3. The flow path 7 is preferably formed to be shorter and have a larger diameter than the flow paths 2 and 2a communicating with the mold outlet 3 so that the deteriorated resin can be discharged quickly. Further, the mold body C is provided with switching valves 8, 12, 13, and 14 as shown in FIGS. 3 to 6, located at the branching points of the flow paths 2 and 7.

The switching valve 8 shown in FIG. 3 is composed of a rotary operation shaft 8a fitted into a through hole 9 formed in the mold body C. This rotary operation shaft 8a has a notch 8b formed on the axis, and the shaft is connected to the bearings 10 and 1.
It is rotatably attached to the mold body C by inserting it into the through hole 9 of the mold body C through 0 and screwing and fixing it with nuts 11, 11. This operating shaft 8a
In place of the notch 8b, a through hole may be provided which is bored substantially perpendicularly toward the axis. In the switching valve 8 of the operating shaft 8a, when the operating shaft 8a is rotated clockwise as shown in FIG. In order to close the channel 7 communicating with the outlet 6, a regular resin extrusion mold can be used. On the other hand, when the operating shaft 8a is rotated counterclockwise as shown in FIG. Since the communicating flow path 2 is closed, it becomes possible to discharge the deteriorated resin. Therefore, the switching valve 8 can switch between extrusion molding and discharge of the resin by selectively opening and closing the channels 2 and 7.

The switching valve 12 shown in FIG. 4 is constructed by mounting an operating shaft 12a on a mold body C, which slides in the front-rear direction as shown in FIG. This operating shaft 12a
There is a through hole 12b that communicates the resin inlet 1 and the flow path 2 of the mold outlet 3 so as to be perpendicular to the axis, the resin outlet 6 opened on the end surface of the shaft, and the flow path 7 of the resin inlet 1. Through holes 12c communicating with each other are provided at different positions. Further, stopper collars 12d and 12e are provided on the sliding end axis of the operating shaft 12a,
The alignment position with each flow path can be specified. In the switching valve 12 of the operating shaft 12a, when the operating shaft 12a is slid until the stopper collar 12d hits the side surface of the mold body C, the through hole 12d connects the flow path 2 between the resin receiving port 1 and the mold outlet 3. At the same time, normal resin extrusion molding can be performed to shift the through hole 12c from the flow path 2. On the other hand, when the operating shaft 12a is slid until the stopper collar 12e hits the side surface of the mold body C, the through hole 12c now blocks the flow path 2 and connects the resin inlet 1 and outlet 6 with the flow path 7. The resin can be discarded to allow communication.

The switching valve 13 shown in FIG.
It is composed of a pair of actuating shafts 13b and 13c that alternately open and close the flow passages 2 and 7 by the operation of 3a. Each of the channels 2 and 7 is provided to be branched in the vertical direction of the mold body C, and the operating shafts 13b and 13c open and close the channels 2 and 7 by protruding or retracting into each channel. Incidentally, each of the operating shafts 13b and 13c can be constituted by a round or square pin.

The switching valve 14 shown in FIG. 6 has a flow path 2 branched in the vertical direction of the mold body C, similar to the embodiment shown in FIG.
7, a pair of screw shafts 14a and 14b that can be screwed in and unscrewed are attached. When configuring the switching valve 14 with these threaded shafts 14a and 14b, if the flow passages 2 and 7 are rectangular,
It is sufficient to attach an auxiliary piece 14d that loosely engages with the protrusion 14c at the tip of the shaft as shown in FIG.

In an extrusion mold configured in this way, if the extrusion of the resin is temporarily stopped at the same time as the feeding of the resin-attached member is stopped, the resin remaining in the bodies of the adapter A and the mold C will be overheated and the material will deteriorate. However, when restarting operation after a temporary stop, the switching valves 8, 12, 13, and 14 are operated to separate the resin inlet 1 and outlet 6. The flow paths are switched in advance so that they communicate. In this state, restart the operation while stopping the feeding of the resin adhesion member, and
When a screw (not shown) located above is driven, at least the resin accumulated in the flow path of the mold body C is discharged out of the mold body C through the flow path 7 and from the discharge port 6. If necessary, the resin accumulated in adapter A can also be discharged. This discharge can be easily completed without taking much time because the flow path 7 is formed to have a large diameter and a short length as explained based on the embodiment shown in FIG. After a certain period of time has passed, wait until all the degraded resin in the mold is discharged and the well-kneaded normal resin is discharged, and then operate the switching valves 8, 12, 13, and 14 again to open the resin receiving port 1. By switching to the flow path 2 that communicates the mold outlet 3 with the mold outlet 3 and restarting the feeding of the resin adhering member which has been stopped until now, regular resin extrusion molding can be carried out in an extremely short time.

In addition, at the start of regular resin extrusion molding, the resin accumulated in the flow path 2 from the mounting position of the switching valves 8, 12, 13, 14 to the mold outlet 3 is discharged, but the amount is extremely small. Therefore, relatively, the amount of waste of the metal core material b can be greatly reduced. In addition, in the above-mentioned embodiment, the resin molding b was attached to the stainless steel core material a, but
The present invention is not limited to this, but can be widely applied to molds for simultaneously extruding decorative films, aluminum strips, metal wire coatings, etc., at the same time.

Effects of the invention As described above, according to the extrusion mold according to the invention, at least the degraded resin remaining in the mold can be disposed of outside the regular flow path by simple operation of the switching valve, and the resin can be removed with the screw. Since the pressure inside the kneading cylinder can be kept constant, the amount of resin-attached members to be discarded can be reduced, and the number of defective products can also be reduced, thereby reducing material costs.

[Brief explanation of drawings]

Fig. 1 is a side cross-sectional view of a conventional extrusion mold, Fig. 2 is a cross-sectional view of a product molded with resin using the same mold, and Fig. 3 a to c are an example of the present invention. FIGS. 4 a to 4 c, and FIGS. 5 and 6 a and b are explanatory views of extrusion molds according to other embodiments. C, c ₁ , c ₂ : Mold body, 1: Inlet, 2: Channel, 3: Mold outlet, 5a, 5b, 5c: Holder slit, 6: Discharge port, 7: Channel, 8, 12 ,1
3, 14: Switching valve, 8a: Rotating operation shaft, 8b: Notch or through hole, 12a: Slide operation shaft, 12
b, 12c: Through hole or notch, 13a: Operation lever, 13b, 13c: Operating shaft, 14a, 14b:
screw shaft.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) A mold body that connects the breaker plate to an adapter provided in the resin flow path, and a resin-attached member such as a metal core material of molding that communicates from the resin inlet to the mold outlet. In addition to providing a constant flow path for the resin to merge into the holder slit inserted through the
The constant flow path is branched from the middle to form a branch flow path that communicates with the resin discharge port, and a switching valve that selectively opens and closes each flow path is installed at the branch point of these flow paths. Extrusion mold. (2) The extrusion molding mold according to claim 1, wherein the switching valve is constituted by a rotary operating shaft having a notch or a through hole communicating with each flow path. (3) The extruded molded metal according to claim 1 of the utility model registration claim, wherein the switching valve is constituted by a slide operation shaft having a notch or a through hole at a different position on the axis that communicates with each flow path. Type. (4) The extrusion molding according to claim 1 of the utility model registration claim, wherein the switching valve is constituted by a pair of operating shafts that selectively protrude and shut off or retract and open each flow path by operating a lever. Mold. (5) Utility model registration claim 1, in which the switching valve is constituted by a pair of threaded shafts that can be selectively screwed in or unscrewed to protrude and shut off or retreat and open each flow path. Extrusion mold as described in section.