JPH01275115A - Mold for injection molding - Google Patents

Abstract

PURPOSE:To carry out the change of resin and the change of resin-color surely and simply by a method in which in the mold for injection molding with a hot runner-structure, a manifold block is caused to be exclusive for each resin, and it may be easily attached to and released from the mold. CONSTITUTION:An exclusive manifold 54 for each molding material is provided. When the material is changed, a mold is opened by engaging the cavity plate 53 of the mold 5 of stationary side with the mold 1 of movable side at the state where the mold is being fitted to a molding machine. The cavity plate 53 is separated from the mold 5 of stationary side, and the manifold block 54 is removed by moving it up and down. The mold is clamped after the prescribed manifold block 5 has been fitted into the prescribed position of the mold 5 of stationary side by the guide groove 52a of a spacer block 52. The cavity plate 53 into which the separate nozzle 54a of the manifold block 54 is inserted, is lapped on the mold 5 of stationary side. Next, the mold is opened by releasing an engaging means 53b, and the cavity plate 53 is fixed to a prescribed position, whereby the replacing operation of the manifold block 54 is finished.

Description

[Detailed Description of the Invention] [Summary] Regarding injection molding molds for plastics, especially injection molding molds having hot runners, dedicated manifold blocks are prepared for each material and the molds are molded. Our aim is to provide an injection mold that allows for easy material changes by simply rearranging the manifold block while still attached to the machine. a cavity plate, which is separated from the manifold block by moving in the mold opening direction together with the movable mold when the mold is opened by an engaging means that engages the movable mold; Manifold Pro is equipped with an individual nozzle that is inserted into a cavity plate and injects molten resin into the cavity, and a hot runner that guides the molten resin injected from a molding machine nozzle to the individual nozzle.The spacer block includes the manifold block. A guide groove is provided for removably guiding and positioning in a direction perpendicular to the mold clamping direction, and when the cavity plate is separated, the manifold block can be removably attached to a predetermined position within the mold.

[Industrial application field]

The present invention relates to a plastic injection mold, and particularly to an injection mold having a hot runner structure.

In injection molding, by injecting molten resin directly into the cavity from the gate, we are able to reduce the amount of material used by eliminating unnecessary parts such as the runner and sprue parts of the molded product. Injection molds with a hot runner structure, equipped with a manifold block containing a heating mechanism to keep the injected resin in a molten state, have come into widespread use.

Recently, molded products have become more diverse in small quantities, with customers requesting molded products in different colors for keyboard key tops, connectors, etc., and it is important to easily and reliably change the material resin during the molding process. A mold structure was needed that would allow for this.

[Conventional technology]

The first figure is a horizontal cross-sectional view of a conventional injection mold, as seen from above when it is attached to a molding machine.

Reference numeral 1 denotes a movable side mold movably attached to a molding machine, which is comprised of a core plate 11 having a core lla formed on its surface, a movable side mounting plate 12, and the like.

Reference numeral 2 designates a stationary side mold, which has a temporary 21 installed on the stationary side, a cavity plate 23 having a cavity 23a via a spacer block 22 fixed to the temporary 21, and a plurality of nozzles 24a and a hot runner 24b. The manifold 24 is stacked in a predetermined position and tightened with a large number of bolts to be integrated.

Clamp the mold in place and move it from the molding machine nozzle 3 to the manifold 24.
When the molten resin 4 is injected onto the sprue 24c, the molten resin passes through the real runner 24h and the nozzle 24a and fills the plurality of cavity spaces formed by the cavity and the core. After cooling and solidifying in the cavity section where the mold temperature is low, the movable mold opens and the molded product is ejected, completing the molding. The resin in the cavity cools and solidifies, but the runner part in the manifold, including the nozzle, is heated by a heater (not shown) to a temperature that keeps the resin in a molten state, so that the resin can be filled into the cavity during the next injection. Since the product does not have a runner part or a spool part, it can be molded with less material loss.

[Problem to be solved by the invention]

In conventional mold construction, the manifold block is fixed to the mold and assembled integrally.

Normally, when changing the resin material to make molded products with different colors, cleaning resin is poured into the manifold to clean it.

However, with this cleaning alone, it is difficult to completely remove the resin from the previous use from inside the manifold, so with conventional technology, it was necessary to remove the mold from the molding machine, disassemble it, and remove the resin inside the manifold. .

Therefore, each time a material is changed, a series of operations such as cooling, removing, disassembling, cleaning, reassembling, attaching, and raising the temperature of the mold are required, which takes time and reduces the operating rate of the molding machine. There was a problem.

The present invention was created in view of the above-mentioned problems.In injection molding with a hot runner structure, a dedicated manifold block is provided for each material, and the manifold brocade is carried out while the mold is attached to the molding machine. The purpose of the present invention is to provide an injection mold that allows material changes to be made simply by rearranging the molds.

[Means to solve the problem]

The above problem is caused by an injection mold consisting of a movable mold and a fixed mold, and the fixed mold has a retaining means that engages with the movable mold, so that when the mold is opened, the movable mold is A cavity plate that moves in the mold opening direction together with the mold and separates from the manifold block; An individual nozzle that protrudes from the surface and is inserted into the cavity plate to inject molten resin into the cavity; and molten resin injected from the molding machine nozzle. a hot runner that guides the manifold block to the individual nozzles; A guide groove is provided for removably guiding and positioning the manifold block in a direction perpendicular to the mold clamping direction, and when the cavity plate is separated, the manifold block is configured to be removable at a predetermined position within the mold. This problem is solved by the injection mold of the present invention, which is characterized by:

[Effect]

Prepare a dedicated manifold for each molding material, and when changing materials, open the mold by engaging the cavity plate of the stationary mold with the movable mold while the mold is attached to the molding machine. . The cavity plate can be separated from the stationary mold and the manifold block can be removed by simply moving it up and down. Then, when the specified manifold block that fits into the guide groove of the spacer block is inserted into the specified position of the stationary side mold and the mold is clamped, the individual nozzles of the manifold block are inserted into the cavity plate and stacked on the stationary side mold. . Next, the retaining means is released, the mold is opened, and the cavity plate is fixed in place, thereby completing the manifold block replacement operation.

Therefore, there is no need for troublesome work such as removing and disassembling the mold from the molding machine to clean the hot runner every time the material is changed, reducing molding time and improving the molding machine operating rate. becomes.

〔Example〕

The present invention will be explained in detail below with reference to the accompanying drawings.

FIG. 1 is a horizontal sectional view of an injection mold according to the present invention, FIG. 2 is a diagram for explaining how to attach and detach a manifold block, and FIG. 3 is a diagram showing a manifold block according to another embodiment. be.

In FIG. 1, reference numeral 1 denotes a movable side mold movably attached to a molding machine, a core plate 11 having a core lla formed on its surface and a pin llb on its side, and a movable side mounting plate 12 etc. to which the core plate is attached. It consists of

5 is a fixed side mold fixed to the molding machine, and is attached to the plate 51
Then, the spacer pro 7 52 fixed to the temporary 51 and the cavity plate 54 having the cavity 54a are laminated and fixed so as to surround the three sides of the mold, and the center formed by the above three members is fixed. A manifold block 54 is incorporated in the space.

Guide pins that guide the opening and closing of the mold, heaters and cooling pipes that keep each part of the mold at a predetermined temperature are not shown.

A plurality of individual nozzles 54a are protruded from the surface of the manifold block 54 on the cavity plate 53 side.
It is inserted into the cavity plate 53 so that its tip abuts on the cavity 53a, and has a hot runner 54b that guides the resin injected from the molding machine to the individual nozzle 54a while keeping it in a molten state.

Also, a guide is provided on the opposing inner wall of the spacer block 52 to guide the side surface of the manifold block 52 so that the manifold block 52 can be moved up and down (perpendicular to the page). 152a is formed,
Further, the side surface of the cavity plate is provided with engagement means such as a flange 53b rotatably held by a pin.

Normal molding using an injection mold with the above configuration is as follows:
When the movable mold 1 is moved to the right and brought into contact with the stationary mold 5 and clamped, and the molten resin 4 is injected from the molding machine nozzle 3 to the spool 54c of the manifold 54, the hot runner 54b and the individual nozzles Molten resin 4 is injected and filled into a plurality of cavity spaces formed by cavity 54a and core lla via 54a. After the molten resin is cooled and solidified in the cavity where the mold temperature is low, the movable mold 1 opens to the left, the molded product is ejected, and one cycle of molding is completed.

Next, with reference to FIG. 2, a procedure for molding molded products of different colors, for example, by changing the resin material, will be explained.

First, with the movable mold open, the mold 53c is removed, and the connection between the cavity plate 53 and the spacer block 52 is released. Next, move the movable side mold to the right so that it comes into contact with the cavity plate 53, engage the engagement means 53 such as the flap and the 7 with the bottle llb of the movable side mold, and then open the mold again. Then, the cavity plate 53 moves in the mold opening direction together with the movable mold, and the stationary mold 5 is divided along the dashed line A- in FIG. 1, and the individual nozzles 54a of the manifold block are exposed to the surface. . In this state, if the manifold block 54 is lifted up by the lifting pole l-54d, it can be easily removed from the mold.

Then, another manifold block 54, which is separately prepared in accordance with the material, is inserted from above while being guided by the guide groove 52 of the spacer block 52a, and is assembled at a predetermined position.

After that, when the mold is clamped, the individual nozzle 54a is inserted from the rear of the cavity plate 53 and properly contacts the cavity 53. Next, when the retaining means 53b with the movable mold is released and the mold is opened, the cavity plate 53 remains on the stationary mold 5 side, so if it is fastened to the spacer block 52 by the pole 53C and integrated, the manifold is completed. The replacement work for block 54 is completed.

The above series of operations are performed while the mold is still attached to the molding machine and by using the mold opening/closing function of the molding machine, so it involves cooling, mold removal, disassembly, reassembly, mold installation, and temperature rise. It is possible to replace the resin material with simple work in a short time.

Figure 3 shows a manifold block that can reduce material loss in the runner when forming by closing part of the gate to reduce the number of cavities in a multi-cavity mold with multi-point gates. This shows a case where the present invention is applied to.

The figure shows the structure of a manifold block when molding is performed by using only the two on the left side of a four-point gate type mold which originally has four individual nozzles 54a, reducing the number of products to be produced by half. The manifold block 54'' is configured to be separable into a cassette type, and a dummy block 55, which does not have a hot runner or individual nozzle and only has a spool portion 55a, is integrated on the right side, and is removable from the fixed side mold. This is what I did.

As a result, all of the molten resin injected from the molding machine is used effectively, and material loss can be reduced compared to the conventional method, which also injects from unused individual nozzles to prevent resin stagnation. be.

〔Effect of the invention〕

As explained above, according to the present invention, in an injection mold having a hot runner structure, a manifold block is specialized for each resin, and the manifold block can be easily attached to and detached from the mold, thereby making it possible to easily change the resin during molding work. It becomes possible to reliably and easily change the resin color, and its practical effects are remarkable.

[Brief explanation of the drawing]

Fig. 1 is a horizontal cross-sectional view of an injection mold according to the present invention, Fig. 2 is a diagram for explaining the method of attaching and detaching the manifold block, and Fig. 3 shows a manifold block of another embodiment. FIG. 4 is a horizontal sectional view of a conventional injection mold. In the figure, l--moving side mold, 3--molding machine nozzle, 4
- Molten resin, 5-.- Fixed side mold, 51-
... Temporary installation, 52- spacer block,
52a--guide groove, 53--cavity plate, 53a--cavity, 53b--one engagement means, 54.54'-
Manifold block, 54a--
Individual nozzle, 54b--Hot runner, 54c-
...Spool, 55--Dummy block. Ａ゛Book 45th H1-stop body 10 Jζ shape sweat t 7 plane cross section 1 edition ¥1 Figure maniho, - Lutobu U, 7 feet 4 skewers η; friend Σ plot silk 6 tanu. 7 2nd unillustrated) Manifold in 1 row, -IL door opening, 7'7.
Figure 3

Claims (1)

[Claims] An injection mold consisting of a movable mold (1) and a fixed mold (5), in which the fixed mold (5) is connected to the movable mold (1). A cavity plate (53) that moves in the mold opening direction together with the movable side mold (1) when the mold is opened by the engaging means (53b) that engages and is separated from the manifold block (54, 54'); An individual nozzle (54a) is inserted into the cavity plate (53) and injects the molten resin into the cavity (53a), and the molten resin (4) injected from the molding machine nozzle (3) is injected into the individual nozzle (54a). a manifold block (54) equipped with a hot runner (54b) that guides the manifold block (54); and a spacer block (54) that is held between the cavity plate (53) and the mounting plate (51) and forms a housing portion of the manifold block (54). 52), the spacer block (52) is provided with a guide groove (52a) for removably guiding and positioning the manifold block (54) in a direction perpendicular to the mold clamping direction; 53) is configured such that when the manifold block (54) is separated, the manifold block (54) can be detached from a predetermined position within the mold.