JP5758735B2 - Mold - Google Patents

Description

  The present invention relates to a mold, and more particularly to a mold including a medium flow path through which a temperature adjusting medium flows.

  In casting, in order to obtain a high-quality molded product, it is necessary to make the temperature distribution on the cavity surface uniform. Therefore, generally, the temperature distribution on the cavity surface is adjusted by forming a medium flow path inside the mold and flowing a temperature adjusting medium such as water whose temperature is adjusted in the medium flow path.

  For example, Patent Document 1 describes a resin injection mold including a hot water circuit for flowing hot water, a cold water circuit for flowing cold water, and an air passage for flowing hot air or cold air. This mold is manufactured by metal stereolithography, and a low-density shaped part having a small sintered density is provided in contact with a resin-molded part (cavity part). And heating and cooling are speeded up by sending warm air or cold air to a resin molding part via an air passage and a low-density modeling part.

  Patent Document 2 describes an injection mold that is formed by rapid prototyping in which a cooling passage through which a cooling fluid such as water is supplied and circulated is formed.

  Patent Document 3 describes that, in a mold in which heat is transferred by a heating or cooling medium flowing through a medium flow path, a plurality of heat insulating portions including gaps are provided in the heat transferred mold portion. Yes. This heat insulating portion is composed of a large number of spherical objects or punching metal sandwiched and bonded between two mold materials.

JP 2009-233980 A JP 2005-219384 A JP 2006-198816 A

  However, the molds described in Patent Documents 1 and 2 are inferior in productivity because the heat transfer efficiency in the cavity surface direction of cooling and heating is not good, and the molding cycle is long and the number of discarded parts increases. There was a problem.

  For example, in the case of heating, even if the medium flow path is formed along the cavity surface, the thermal conductivity of the mold is very high, so that not only the cavity surface direction that requires heating but also heating is unnecessary. A large amount of heat is also transferred to the inside of the mold. For this reason, in order to quickly heat the cavity surface, a large amount of heat input is required, and it is necessary to increase the temperature, flow rate, pressure, etc. of the heating medium.

  Moreover, in the metal mold | die described in patent document 3, the site | part which can provide a heat insulation part was very limited, and there existed a problem that a heat insulation part could not be provided along the cavity surface of a complicated shape.

  In view of the above, an object of the present invention is to provide a mold having good heat transfer efficiency from a medium flow path to a cavity surface direction even if the cavity surface has a complicated shape.

  The present invention is a mold having a cavity for forming a molded product and a medium flow path through which a temperature adjusting medium flows along the cavity, and is manufactured by rapid prototyping. A heat insulating path in which air is present is formed.

  According to the present invention, heat transfer from the temperature adjusting medium flowing through the medium flow path is suppressed by air having a large heat insulating effect existing inside the heat insulating path. Therefore, by forming the heat insulating path at an appropriate position, the cavity surface can be quickly and uniformly cooled and heated by heat transfer from the temperature adjusting medium flowing through the medium flow path. This shortens the production cycle of the molded product and improves the quality.

  In addition, since the mold is manufactured by rapid prototyping, even if the medium flow path and the heat insulating path have a complicated three-dimensional shape, these can be formed simultaneously in the process of manufacturing the mold, Manufacturing efficiency is excellent.

  In this invention, it is preferable that the said heat insulation path is formed in the opposite side to the said cavity part with respect to the said medium flow path.

  In this case, heat transfer from the temperature adjusting medium flowing through the medium flow path in the direction opposite to the cavity portion is suppressed by the heat insulating path. Therefore, the heat transfer efficiency from the medium flow path toward the cavity portion is improved, the cavity surface can be quickly cooled and heated, and the production cycle of the molded product is shortened.

In the present invention, the insulation paths, that are formed so as to extend in a direction inclined from the direction of extension of the medium flow path.

Thereby , the heat insulation effect by a heat insulation path differs according to the angle which a heat insulation path and a medium flow path make. For example, if the heat insulating path and the medium flow path are orthogonal to each other, the heat insulating effect is small, and the heat insulating effect is increased as they approach parallel.

  Therefore, by appropriately setting the angle between the heat insulating path and the medium flow path, the cavity surface can be uniformly cooled and heated by the heat transfer from the temperature adjusting medium flowing through the medium flow path. Improve the quality. Further, this makes it possible to suppress local overheating inside the mold, and the mold is prevented from being deformed and the life is improved.

It is a figure explaining the metal mold | die which concerns on embodiment of this invention, (a) is a front view, (b) is the BB sectional drawing of (a). It is sectional drawing explaining the metal mold | die which concerns on the deformation | transformation of embodiment, (a) is a case where a heating path is formed in the vicinity of a cavity surface, (b) is a cooling path, a heating path, and another cavity surface. The case where the heat insulation path is formed between each is shown. It is a figure explaining the metal mold | die which concerns on another deformation | transformation of embodiment, (a) is a front view in case a heat insulation path is formed orthogonally to a heating path, (b) is a heat insulation path from a heating path. Sectional drawing in the case of being formed inclined is shown, and (c) is a front view in the case where the heat insulating path is formed deviating from the heating path.

  Hereinafter, the metal mold | die which concerns on embodiment of this invention is demonstrated.

  Since the basic configuration of the mold according to the present embodiment is the same as a well-known one, detailed description other than the features of the present invention is omitted.

  Although not shown, the mold is composed of a mold divided into two, that is, a divided mold. One split mold is a fixed mold and the other split mold is a movable mold. The fixed mold is fixed to the support base, and the movable mold is provided so as to be close to and away from the fixed mold, and the movable mold is clamped and opened with respect to the fixed mold. A cavity portion, a pouring portion, a hot water escape portion, and the like are formed on the mating surface (parting surface) of the fixed mold and the movable mold. The cast product is formed into the shape of the cavity. The surface of the cavity portion is the cavity surface.

  Furthermore, a molten metal supply device that supplies the molten metal to the cavity portion via the pouring portion is provided at the lower portion of the mold. A molten metal supply apparatus consists of plungers etc., and supplies molten metals, such as an aluminum alloy, a magnesium alloy, a zinc alloy, and a synthetic resin.

  Next, the mold temperature adjustment mechanism, which is a feature of the present invention, will be described. In the present embodiment, the temperature adjustment mechanism 10 is provided in at least one of two divided molds, that is, a fixed mold and a movable mold. Here, as shown in FIGS. 1A and 1B, it is assumed that the temperature adjustment mechanism 10 is provided in the split mold 20.

  The temperature adjustment mechanism 10 includes a cooling path 11 through which a cooling medium flows, a heating path 12 through which a heating medium flows, and a heat insulating path 13 in which air exists. The cooling medium and the heating medium are, for example, a fluid such as water or oil, or a gas such as air. The cooling medium and the heating medium correspond to the temperature adjusting medium of the present invention, and the cooling path 11 and the heating path 12 correspond to the medium flow path of the present invention.

  The separation mold 20 is manufactured using rapid prototyping (in recent years, also referred to as additive manufacturing). Specifically, the separation mold 20 is manufactured by a powder sintering lamination method in which a raw metal powder is spread in layers and directly sintered with a high-power laser beam or the like. Therefore, even if the cooling path 11, the heating path 12, and the heat insulating path 13 have a complicated three-dimensional shape, these are simultaneously formed in the process of manufacturing the separation mold 20, and the manufacturing efficiency is excellent.

  Here, the cooling path 11 is three parallel holes formed in the vicinity of the cavity surface 21 along the cavity surface 21. The heating path 12 is three parallel holes formed along the cooling path 11 in parallel with the cooling paths 11 and on the opposite side of the cooling path 11 from the cavity surface 21. The heat insulating path 13 is three parallel holes formed on the side opposite to the cavity surface 21 with respect to the heating path 12 in parallel with the respective heating paths 12 along the heating path 12.

  In addition, the structure and arrangement | positioning of the cooling path 11, the heating path 12, and the heat insulation path 13 are not limited to this. For example, the cooling path 11 and the heating path 12 may be alternately formed in the vicinity of the cavity surface 21 along the cavity surface 21. Moreover, the arrangement | positioning relationship of the heating path 12 and the heat insulation path 13 may change with places.

  However, it is preferable that at least a part of the heat insulating path 13 is formed on the side opposite to the cavity surface 21 with respect to the cooling path 11 and the heating path 12. In addition, you may form the heat insulation path 13 in the site | part which does not follow the cooling path 11 or the heating path 12 as needed.

  Here, the cross-sectional shapes of the cooling path 11, the heating path 12, and the heat insulating path 13 are circular and substantially identical to each other, and are constant over the entire length. However, the cross-sectional shape is not limited to a circular shape, and may be an arbitrary shape such as an elliptical shape, an egg shape, or a polygonal shape such as a rectangular shape. In addition, the cross-sectional shapes of the cooling path 11, the heating path 12, and the heat insulating path 13 may not be substantially the same. For example, the cross-sectional shapes of the three heat insulating paths 13 may be different from each other. For example, the cross-sectional shape of one heat insulation path 13 may differ according to a place.

  Although not shown, the inlet end of the cooling path 11 is connected to a cooling device. The cooling device cools the cooling medium to a temperature commanded by the control device, and supplies the cooling medium into the cooling path 11 from the inlet end. And the cooling medium which flowed through the cooling path 11 is discharged | emitted from the exit edge part outside.

  Similarly, in the heating path 12, a heating device is connected to the inlet end, and the heating medium is discharged to the outside from the outlet end. Note that the cooling medium or the heating medium may return to the cooling device or the heating device from the outlet end portion and circulate.

  The heat insulating path 13 is a simple through hole, and both end portions thereof are open to the outside at the end face of the split mold 20. However, both ends of the heat insulating path 13 are not necessarily open to the outside, and may be blind holes or holes that do not communicate with the outside. In addition, since the metal powder remains in the hole during the manufacturing by rapid prototyping, it is preferable that the heat insulating path 13 communicates with the outside in order to discharge the metal powder.

  In this way, since air having a large heat insulating effect exists in the heat insulating path 13, a heat insulating layer made of air is provided in the heat insulating path 13.

  As described above, along the cooling path 11 and the heating path 12, the heat insulating layer made of air existing inside the heat insulating path 13 is provided on the opposite side to the cavity surface 21. Therefore, it is possible to suppress unnecessary heat transfer from the medium flowing through the cooling path 11 and the heating path 12 toward the inside of the split mold 20. Therefore, the amount of heat transfer from the medium flowing through the cooling path 11 and the heating path 12 toward the cavity surface 21 increases, the heat transfer efficiency toward the cavity surface 21 improves, and the heat transfer speed increases.

  Therefore, the cavity surface 21 can be quickly cooled and heated. Then, the cavity surface 21 is rapidly cooled, so that the molding cycle is shortened. Further, the cavity surface 21 is heated quickly, so that the number of throwing away is reduced and the rise time is shortened. By these, productivity becomes excellent.

  In particular, since the heat insulating path 13 is formed in parallel with the cooling path 11 and the heating path 12, heat transfer in the direction opposite to the cavity surface 21 is efficiently prevented, and the inside of the cooling path 11 and the heating path 12. The cavity surface 21 can be rapidly cooled and heated by the medium flowing through the. Thereby, a molding cycle can be shortened and productivity can be improved.

  Further, for example, it is necessary to release a large amount of heat from the cavity surface 21 facing the thick part of the molded product. For this purpose, the cooling path 11 may be formed in the vicinity of the cavity surface 21 and the heat insulating path 13 may be formed in the vicinity of the cooling path 11 opposite to the cavity surface 21. At this time, it is preferable to reduce the cross-sectional area of the heat insulating path 13.

  On the other hand, if heat is rapidly released from the cavity surface 21 facing the thin part or the protruding part of the molded product, the temperature of this part may be excessively lowered as compared with other parts. Therefore, the cooling path 11 may be formed with a certain distance from the cavity surface 21, and the heat insulating path 13 may be provided with a certain distance on the opposite side of the cooling path 11 from the cavity surface 21. At this time, it is preferable to increase the cross-sectional area of the heat insulating path 13.

  Thus, the cavity surface 21 can be uniformly cooled and heated by appropriately setting the arrangement and the cross-sectional shape of the heating path 11, the cooling path 12, and the heat insulating path 13. Thereby, the external appearance and internal quality of the molded product are improved, and the dimensional accuracy is also excellent. Moreover, it becomes possible to suppress the local overheating inside the split mold 20, and the deformation of the split mold 20 is suppressed and the life is improved.

  The heating path 11 and the cooling path 12 are performed by performing simulations and experiments in consideration of the strength so that the cavity surface 21 is cooled and heated quickly and uniformly and local overheating of the split mold 20 is suppressed. In addition, it is possible to set the arrangement, cross-sectional shape, and the like of the heat insulating path 13 to an appropriate one.

  As mentioned above, although embodiment of this invention was described, this invention is not limited to this. For example, the cooling path 11 is formed closer to the cavity surface 21 than the heating path 12, because this places importance on rapidly cooling the cavity surface 21. When it is important to heat the cavity surface 21 quickly, the heating path 12 may be formed closer to the cavity surface 21 than the cooling path 11 as shown in FIG.

  Further, when the cavity surface 21 is rapidly cooled and heated locally, a heat insulating path is formed between the cooling path 11 and the heating path 12 and other portions of the cavity surface 21 as shown in FIG. 13 may be formed.

  Moreover, although the heat insulation path 13 was formed in parallel with these along the cooling path 11 and the heating path 12, this is because importance was attached to the heat insulation effect. For example, when it is desired to suppress the heat insulating effect such as when the temporary stop (choco stop) is short and it is desired to heat gently, as shown in FIG. 3 (a), it is orthogonal to the extending direction of the cooling path 11 and the heating path 12. What is necessary is just to form the heat insulation path 13 so that it may extend in a direction.

  In this case, as shown in FIG. 3B, the heat insulating path 13 may be formed by shifting from the cooling path 11 and the heating path 12. That is, the heat insulating path 13 may be formed so as not to overlap the cooling path 11 and the heating path 12 or to reduce the overlapping area in the internal direction of the split mold 20 from the cavity surface 21. Also by this, the heat insulation effect can be suppressed.

  Furthermore, when it is desired to give directionality to the heat transfer inside the split mold 20, as shown in FIG. 3C, the heat insulating path extends in a direction inclined from the direction in which the cooling path 11 and the heating path 12 extend. 13 may be formed.

  Although not shown, only one of the cooling path 11 and the heating path 12 may be formed. Further, the cooling and heating medium may flow in the same medium flow path. Further, although the casting mold has been described, the present invention is not limited thereto, and may be applied to a mold for injection molding or the like.

  DESCRIPTION OF SYMBOLS 10 ... Temperature adjustment mechanism, 11 ... Cooling path (medium flow path), 12 ... Heating path (medium flow path), 13 ... Heat insulation path, 20 ... Split type | mold (mold), 21 ... Cavity surface.

Claims (2)

A mold having a cavity part for forming a molded product and a medium flow path through which the temperature adjusting medium flows along the cavity part, and manufactured by rapid prototyping,
A mold characterized in that a heat insulating path in which air is present is formed so as to extend in a direction inclined from a direction in which the medium flow path extends .   The mold according to claim 1, wherein the heat insulating path is formed on a side opposite to the cavity portion with respect to the medium flow path.

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