JP2010173283A - Mold structure for hot runner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a mold structure for hot runner free from the concern about resin leakage. <P>SOLUTION: In a fixed mold 1, a cavity block 5 is fixed to a fixed mounting plate 3 via a spacer 4, a manifold 6 is arranged inside the cavity block and the fixed mounting plate, and a packing 7 is arranged in the outlet side of a material passage 6a in the manifold. In a movable mold, a core block is fixed to a movable mounting plate. The mold structure comprises the fixed mold and the movable mold, wherein a molten resin material is introduced from a nozzle 16 into the material passage in the manifold and is charged from a hot nozzle 10 in the cavity block to a product cavity 11 formed between the core block and the cavity block. The manifold is arranged in a space 13 secured between the fixed mounting plate and the cavity block to absorb thermal expansion upon a temperature rise of the manifold, and the packing in the manifold side is elastically energized in the opening direction of the hot nozzle by interposing a regulation spring 15 between the manifold and the fixed mounting plate. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a mold structure for hot runners used for injection molding of thermoplastic resins.

  As shown in FIGS. 5 and 6, this conventional hot runner mold comprises a fixed mold 21 and a movable mold 22, and the fixed mold 21 has a cavity block on its fixed side mounting plate 23 via a spacer 24. 25, and a manifold 26 having a material passage 26a is disposed inside the cavity block 25 and the fixed side mounting plate 23. The manifold 26 is connected to the runner pad 27 on the fixed side mounting plate 23 side. Are integrally provided, and the packing 28 is integrally provided on the cavity block 25 side. The movable mold 22 has a configuration in which the core block 30 is fixed to the movable side mounting plate 29, and the product cavity 32 is formed by the convex portion 30a of the core block 30 and the concave portion 25a of the cavity block 25. Yes.

  When injection molding is performed using the hot runner mold configured as described above, first, after mold clamping, the gate of the hot nozzle 31 provided inside the cavity block 25 is set in an open state. When the molten resin material is introduced from the nozzle 33 of the injection unit (not shown) into the material passage 26a of the manifold 26, the molten resin material is filled into the product cavity 32 from the gate of the hot nozzle 31. After that, if this is cooled and solidified, a product is formed. Therefore, this time, if the gate of the hot nozzle 31 is set in a closed state and the mold is opened, the molded product can be taken out.

  However, under the conventional hot runner mold, the temperature of the manifold 26 rises to about 200 degrees during operation. On the other hand, the fixed side mounting plate 23, the spacer 24, and the cavity block 25 are close to room temperature. Since the temperature is controlled, when the heating means for maintaining the manifold 26 at the resin melting temperature is shut off after the product is molded, the manifold 26 cools down as shown in FIG. When the packing 28 is retracted from the opening of the hot nozzle 31 due to contraction to Y, a displacement L is generated between the material passage 26 a of the manifold 26 and the opening of the hot nozzle 31. The resin material in the material passage 26a leaks into the gap, and the sensor for controlling the temperature of the manifold 26 and the wiring of the heating means are disconnected by the molten resin material. Failure to case has been seen often.

  The present invention was developed in order to effectively solve the problems of such a conventional hot runner mold structure. The invention according to claim 1 comprises a fixed mold and a movable mold. The cavity block is fixed to the fixed side mounting plate via a spacer, a manifold having a material passage is disposed inside the cavity block and the fixed side mounting plate, and packing is performed on the outlet side of the material path of the manifold. From the hot nozzle provided inside the cavity block, the movable mold fixes the core block to the movable side mounting plate, guides the resin material melted from the nozzle of the injection unit into the material passage of the manifold, In the mold structure for hot runner that fills the product cavity formed between the core block and the cavity block, A space that can absorb thermal expansion when the manifold is heated is secured between the cavity blocks, and the manifold is disposed in the space, while a regulating spring is interposed between the manifold and the fixed mounting plate. Thus, the packing on the manifold side is always elastically biased in the opening direction of the hot nozzle by the spring pressure of the regulating spring.

  According to a second aspect of the present invention, on the premise of the first aspect, the regulating spring is located on the same line as the manifold side packing.

  Therefore, in the invention of the first aspect, as in the conventional case, when the heating means for maintaining the manifold at the resin melting temperature is shut off, the manifold is cooled and contracted in the thickness direction and the longitudinal direction. However, in such a state, the packing provided on the manifold side is elastically urged in the opening direction of the hot nozzle by the spring pressure of the regulating spring, and the packing and the opening side of the hot nozzle are displaced. Since it can be prevented from occurring, there is no risk of the resin material existing in the material passage of the manifold leaking out. For this reason, there is no fear that the sensor for controlling the temperature of the manifold and the wiring of the heating means are disconnected by the molten resin.

  In the invention of claim 2, since the regulating spring and the packing on the manifold side are located on the same line, the spring pressure of the regulating spring acts directly on the manifold, and the packing is opened to the hot nozzle. It is possible to press strongly against the side.

  The present invention comprises a fixed mold and a movable mold, and the fixed mold has a cavity block fixed to the fixed mounting plate via a spacer, and has a material passage inside the cavity block and the fixed mounting plate. A manifold is provided, packing is provided on the outlet side of the material passage of the manifold, and the movable mold has a core block fixed to the movable side mounting plate, and the resin material melted from the nozzle of the injection unit is supplied to the manifold material passage. Assuming a hot runner mold structure that fills the product cavity formed between the core block and the cavity block from the hot nozzle provided inside the cavity block, the fixed side mounting plate and the cavity Secure a space between the blocks that can absorb the thermal expansion of the manifold when the temperature rises, and place the manifold in the space. On the other hand, a restriction spring is interposed between the manifold and the fixed-side mounting plate, and the manifold side packing is always elastically biased in the opening direction of the hot nozzle with the spring pressure of the restriction spring. In particular, the resin leakage is effectively prevented when the manifold contracts.

  Hereinafter, the present invention will be described in detail on the basis of a preferred embodiment shown in the drawings. A hot runner die according to the embodiment is basically a fixed die 1 as shown in FIG. The fixed die 1 has a cavity block 5 fixed to the fixed side mounting plate 3 via a spacer 4, and a material passage 6 a is formed inside the cavity block 5 and the fixed side mounting plate 3. And a packing 7 is provided on the outlet side of the material passage 6a of the manifold 6, and the movable die 2 has a core block 9 fixed to the movable side mounting plate 8 and a nozzle 16 of the injection unit. The melted resin material is guided into the material passage 6 a of the manifold 6, and from the hot nozzle 10 provided inside the cavity block 5, the convex portion 9 a of the core block 9 and the concave portion 5 of the cavity block 5. It assumes a configuration to be filled into the mold cavity 11 which is formed between the.

  The hot nozzle 10 engages with an engagement hole 12 formed in the cavity block 5 and opens its gate toward the product cavity 11. The fixed side mounting plate 3 and the movable side mounting plate 8 are supported by an injection molding machine (not shown).

  The feature of this embodiment is that, as shown in FIG. 2, a space 13 is secured between the fixed side mounting plate 3 and the cavity block 5 so as to absorb the thermal expansion of the manifold 6 when the temperature is raised. While the manifold 6 is disposed in the space 13 in a free state, a storage groove 14 is formed in a portion of the fixed side mounting plate 3 corresponding to the hot nozzle 10, and the storage groove 14 of the fixed side mounting plate 3 and the manifold are formed. A compression coil-shaped regulation spring 15 is interposed between the cylinder 6 and the packing 7 on the manifold 6 side is always elastically biased in the opening direction of the hot nozzle 10 by the spring pressure of the regulation spring 15. It is in the point.

  Therefore, under the present embodiment, the regulation spring 15 is located on the same line as the packing 7 on the manifold 6 side, so that the spring pressure of the regulation spring 15 directly acts on the manifold 6 to remove the packing 7. It becomes possible to press strongly against the opening side of the hot nozzle 10.

  Therefore, when injection molding is performed using the hot runner mold having such a configuration, first, after clamping, the gate of the hot nozzle 10 engaged with the engagement hole 12 of the cavity block 5 is opened. When the resin material melted from the nozzle 16 of the injection unit (not shown) is introduced into the material passage 6a of the manifold 6 in the open state, the melted resin material flows from the gate of the hot nozzle 10 to the product cavity 11. Since the inside is filled, if it is cooled and solidified later, the product is molded. Therefore, this time, if the gate of the hot nozzle 10 is set in a closed state and the mold is opened, the molded product can be easily taken out.

  During this operation, when the temperature of the manifold 6 rises to about 200 degrees, the manifold 6 is thermally expanded in the thickness direction and the longitudinal direction. 3, the regulation spring 15 contracts and effectively absorbs the thermal expansion in the thickness direction, so that the fixed side mounting plate 3 and the packing 7 can be protected.

  As for thermal expansion in the longitudinal direction, the manifold 6 slides on the surface of the cavity block 5 together with the packing 7 as shown in the figure. At this time, the biasing spring pressure of the regulating spring 15 is received. Since the packing 7 is in elastic contact with the opening side of the hot nozzle 10, airtightness is thereby maintained, and no deviation occurs between the material passage 6 a of the manifold 6 and the opening of the hot nozzle 10.

  Conversely, when the molding process is completed and the heating means of the manifold 6 is shut off, the manifold 6 is cooled and contracts. In this case, the contraction X in the thickness direction is restricted as shown in FIG. The spring 15 is extended and strongly presses the packing 7 against the opening side of the hot nozzle 10 to maintain airtightness. At the same time, with respect to the contraction Y in the longitudinal direction, the manifold 6 slides on the surface of the cavity block 5 together with the packing 7. At this time, the packing 7 is strongly elastically brought into contact with the opening side of the hot nozzle 10 due to the biasing spring pressure of the restriction spring 15. Is effectively suppressed, and no deviation occurs between the material passage 6 a of the manifold 6 and the opening of the hot nozzle 10. Therefore, this can effectively prevent resin leakage.

  In addition, in any case, since the regulation spring 15 is located on the same line as the packing 7 on the manifold 6 side, the spring pressure of the regulation spring 15 directly acts on the manifold 6 to remove the packing 7 from the hot nozzle. 10 can be pressed strongly against the opening side, and even if the manifold 6 is thermally expanded or contracted, those phenomena can be effectively suppressed, so that the airtightness can be reliably maintained. The Rukoto.

  The mold structure for hot runners according to the present invention can prevent the resin leakage particularly when the manifold contracts and can effectively prevent the sensor for controlling the temperature of the manifold and the wiring of the heating means from being disconnected. If it is used for injection molding of thermoplastic resin, it will be very convenient.

It is explanatory drawing which partially shows the metal mold | die structure for hot runners concerning the Example of this invention. It is principal part sectional drawing which shows the non-operation state in the metal mold | die structure for the hot runner. It is principal part sectional drawing which shows the operation state in the metal mold | die structure for the hot runner. It is principal part sectional drawing which shows the contraction state in the metal mold | die structure for the hot runners. It is explanatory drawing which shows a partial cross section of the conventional mold structure for hot runners. It is principal part sectional drawing which shows the non-operation state in the metal mold | die structure for the hot runner. It is principal part sectional drawing which shows the contraction state in the metal mold | die structure for the hot runners.

DESCRIPTION OF SYMBOLS 1 Fixed type 2 Movable type 3 Fixed side mounting plate 4 Spacer 5 Cavity block 5a Concave 6 Manifold 6a Material passage 7 Packing 8 Movable side mounting plate 9 Core block 9a Convex 10 Hot nozzle 11 Product cavity 12 Engagement hole 13 Space 14 Storage Groove 15 Regulating spring 16 Nozzle L Deviation X Shrinkage in the thickness direction Y Shrinkage in the longitudinal direction

Claims (2)

  The fixed mold is composed of a fixed mold and a movable mold. The fixed mold has a cavity block fixed to the fixed mounting plate via a spacer, and a manifold having a material passage inside the cavity block and the fixed mounting plate is disposed. Then, packing is provided on the outlet side of the material passage of the manifold, and the movable type fixes the core block to the movable side mounting plate, and guides the resin material melted from the nozzle of the injection unit into the material passage of the manifold. In the mold structure for hot runner that fills the product cavity formed between the core block and the cavity block from the hot nozzle provided inside the cavity block, the manifold is arranged between the fixed side mounting plate and the cavity block. While securing a space that can absorb the thermal expansion at the time of temperature rise and arranging a manifold in the space, A hot spring characterized in that a restriction spring is interposed between the manifold and the fixed side mounting plate, and the packing on the manifold side is always elastically biased in the opening direction of the hot nozzle by the spring pressure of the restriction spring. Runner mold structure.   The mold structure for a hot runner according to claim 1, wherein the regulating spring is located on the same line as the packing on the manifold side.

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