Injection mold apparatus with a cooling and heating passage

The present invention has a cooling and heating passage that can form a cooling and heating passage adjacent to the molding space inside the mold body, and can easily design a cooling and heating passage even in a molding space having a complicated trajectory. Regarding injection molds.

Injection molding is a process in which a polymer resin is plasticized by applying heat and then the molten polymer resin is injected into an injection mold using hydraulic pressure to form a variety of sizes. It has the advantage of being able to mass-produce standard products.

However, molding of a general polymer resin has a problem that the appearance is spoiled by the weld line generated when the molten resin meets inside the injection mold, and the surface gloss is not excellent. there were.

In order to improve this problem, a heat molding method in which the temperature of the injection mold is set higher than the melting temperature of the polymer resin to be molded has been widely used. As an example, Japanese Patent Application Laid-Open No. 45-22020, Japanese Patent Application Laid-Open No. 51-22759, Japanese Patent Application Laid-Open No. 55-109639, Japanese Patent Application Laid-Open No. 57-165229, Japanese Patent Application Laid-Open No. 61-79614, Japanese Patent Application Laid-Open No. There are 4-265720 and so on.

However, when the polymer resin is molded by setting the mold temperature higher than the melting temperature of the polymer resin in this way, weld lines do not occur and the glossiness is excellent. Although it is improved, there is a problem that the product production efficiency is lowered because the cooling time is extended due to the high mold temperature and the entire molding cycle is extended.

In order to solve this problem, Korean Patent No. 10-00811909 discloses an automatic temperature control system for injection dies, and Korean Patent No. 10-0167711 discloses a mold cooling system. , Korean Patent No. 10-0470835 discloses a mold temperature control system. In addition, Korean Patent No. 10-0701229 presents a structure in which rapid heating and cooling of the mold are performed within the range of 100 to 200 ° C / min.

However, this structure does not have to cool and heat the injection mold within a short time, so that the above-mentioned problems cannot be fundamentally solved. In addition, since many cooling lines and hot water supply lines are formed in this injection structure for cooling and heating, the mold structure is relatively weak and the mold is deformed during repetitive molding work. was there. In particular, in the conventional injection mold, in order to reduce the heat capacity for heating and cooling, a lead-in portion is formed in the lower part of the injection mold corresponding to the cavity to reduce the heat capacity. However, when the lead-in portion is formed in the lower part of the mold in this way, there is a problem that the mold becomes relatively weak and cracks occur due to external impact or repeated injection molding.

On the other hand, in the conventional weldless type injection mold, in order to cool and heat the injection mold, a cooling and heating passage is formed in the main body of the injection mold so as to be close to the molding locus along the locus of the molding space. Was presented.

Although this method excels in the performance of the cooling and heating system of the weldless mold or injection mold, the cooling and heating passages provided in the upper and lower molds or cores forming the molding space are formed in close proximity to the molding space. If this is not done, the cooling and heating effects cannot be maximized, and especially when forming a conduit through which cooling water or hot water passes, if the structure of the molding space is complex, the conduit is uniform along the molding space. Since it cannot be formed to a sufficient thickness, there is a problem that the cooling efficiency of the injection-molded product is inferior.

Therefore, it has become necessary to develop an injection mold in which it is easy to form a cooling or heating passage of the injection mold close to the molding space of the injection mold.

<p num="0011"><patcit num="1"><text>JP 2009-34695</text></patcit><patcit num="2"><text>Korean Patent Application Laid-Open No. 10-2011-0055956</text></patcit><patcit num="3"><text>U.S. Pat. No. 7172405</text></patcit></p>

<p num="0012"> The present invention has been devised to solve the problems of the above-mentioned conventional techniques, and an object thereof is a cooling and heating passage inside the mold body of the upper mold and the lower mold so as to be adjacent to the molding space. It is an object of the present invention to provide an injection mold having a cooling and heating passage capable of forming the above.</p><p num="0013"> Another object of the present invention is to provide an injection mold having a cooling and heating passage for which a cooling and heating passage can be easily designed even in a molding space having a complicated locus. </p>

<p num="0014"> The present invention is configured to include a lower mold and an upper mold that forms a hollow molding space with the lower mold at the upper part of the lower mold, and the lower mold or the upper mold is melted. A mold main body in which a molding space is formed on one surface so that the resin is injected and the shapes are aligned, and one surface of the mold body in which the molding space is formed are recessed in the direction of the molding space. Includes a connecting groove and a seal kit that is inserted into the connecting groove and inserted so as to be separated from the molding space-side end of the connecting groove to form a cooling and heating passage in the separated space. It is characterized by being composed. </p><p num="0015"> Further, in the present invention, the connecting groove is formed by superimposing a plurality of vertical holes formed so as to be close to the bottom surface of the molding space, and the seal kit is formed by superimposing a plurality of pillar portions. It is a feature. </p>

<p num="0016"> As described above, according to the present invention, since the cooling and heating passages can be formed inside the mold bodies of the upper and lower molds adjacent to the molding space, the heating and cooling time of the resin during injection molding of the product can be set. It can be shortened, and thus the injection molding cycle time of the product can be shortened to improve the productivity. </p><p num="0017"> Further, in the present invention, by machining each vertical hole, a flow path is formed by the overlapping vertical holes, so that a cooling and heating passage can be easily designed even in a molding space having a complicated locus. </p>

<figref num="1">FIG. 1 is a cross-sectional view of an injection mold having a cooling and heating passage according to an embodiment of the present invention.</figref><figref num="2">FIG. 2 is a partially cut and separated perspective view of an injection mold having a cooling and heating passage according to the embodiment of the present invention.</figref><figref num="3">FIG. 3 is a partially cut separated perspective view of another embodiment of an injection mold having a cooling and heating passage according to the embodiment of the present invention.</figref>

Hereinafter, an injection mold having a cooling and heating passage according to an embodiment of the present invention will be described in detail based on the attached drawings.

FIG. 1 is a cross-sectional view of an injection mold having a cooling and heating passage according to the embodiment of the present invention, and FIG. 2 is a partially cut and separated perspective view of the injection mold having a cooling and heating passage according to the embodiment of the present invention. , FIG. 3 is a partially cut separated perspective view of another embodiment of an injection mold having a cooling and heating passage according to the embodiment of the present invention.

According to FIGS. 1 to 3, the injection mold having the cooling and heating passages according to the present invention is provided with the lower fixing plate 11 and the upper fixing provided on the upper part of the lower fixing plate 11 facing the lower fixing plate 11. It is composed of a plate 12, a lower mold 30 bonded to the upper portion of the lower fixing plate 11, and an upper mold 20 bonded to the lower portion of the upper fixing plate 12 to form a mold with the lower mold 30.

The lower fixing plate 11 serves as a normal support base and fixes the lower mold 30 so that the mold process can be performed stably. Therefore, the lower base can be formed into a flat plate shape, a frame shape, or the like, and it is sufficient if the lower mold 30 can be stably fixed. Therefore, the shape is not limited in the present invention.

The upper fixing plate 12 is formed so as to be movable so that the upper mold 20 fixed to the lower part can be combined with or separated from the lower mold 30. Therefore, the upper fixing plate 12 is moved to the upper part by a rack gear (not shown), a hydraulic cylinder (not shown), etc., and is lowered when the injection product is formed so that the upper mold 20 and the lower mold 30 are hermetically coupled. , When the injection product is completed, it rises to separate the upper mold 20 and the lower mold 30 so that the completed injection product can be recovered. Like the lower fixing plate 11, such an upper fixing plate 12 can be formed in a flat plate shape or a frame shape, and the shape is not limited in the present invention. The means for moving the upper fixing plate 12 is not limited to the type thereof in the present invention, and a known power transmission means for moving the upper fixing plate 12 so that the upper mold 20 and the lower mold 30 can be separated or combined can be easily used. Of course, it can be used.

On the other hand, as shown in FIG. 1, according to the embodiment of the present invention, the configurations of the upper mold 20 and the lower mold 30 are the same as each other, so the configuration of the lower mold 30 will be mainly described below. Each configuration of the lower mold 30 described later is also applied to the upper mold 20.

The lower mold 30 has a mold main body 31 in which a molding space 13 is formed on the upper surface so that the molten resin is injected to align the shapes, and a fixed distance from the lower surface of the mold main body 31 to the bottom surface of the molding space 13. Includes a connecting groove (connecting groove) 40 recessed so as to be separated by, and a seal kit 50 inserted into the connecting groove 40 to form a cooling and heating passage 60 between the ends of the connecting groove 40. It is composed of.

To explain this in more detail, in the connecting groove 40, a plurality of vertical holes 41 are superposed on the mold body 31 of the lower mold 30 so as to be adjacent to the molding space 13 from the lower surface of the mold body 31 (communication in the substantially horizontal direction). Is formed. That is, the connecting groove 40 is formed by being recessed in a shape in which the vertical holes 41 are superimposed in the direction of the molding space 13 from the opposite one surface on which the molding space 13 of the mold main body 31 is formed. The vertical hole 41 can be formed from the lower surface of the mold body 31 through drilling or the like, and the end of the continuous vertical hole 41 on the molding space 13 side is separated from the end of the seal kit 50 on the molding space 13 side, which will be described later. The cooling and heating passages 60 will be formed. The vertical hole 41 need only be oriented in the direction of the molding space 13 from the opposite surface on which the molding space 13 of the mold main body 31 is formed, and does not necessarily have to be exactly perpendicular to one surface.

The seal kit 50 is formed so as to have the same cross-sectional shape as the cross-sectional shape of the connecting groove 40, is inserted so as to be separated from the end portion of the connecting groove 40 on the molding space 13 side, and is cooled and cooled in the separated space. It plays a role in forming the heating passage 60. That is, the outer peripheral edge of the seal kit 50 and the inner peripheral edge into which the seal kit 50 of the connecting groove 40 is inserted are in close contact with each other and sealed, and the end portion of the connecting groove 40 on the molding space 13 side and the sealing of the connecting groove 40 are sealed. The space surrounded by the inner peripheral edge into which the kit 50 is not inserted and the end portion of the seal kit 50 on the molding space 13 side becomes the cooling and heating passage 60. Therefore, as shown in FIG. 2, the seal kit 50 is formed by superimposing a plurality of pillars 51, and the shape thereof is a cross-sectional shape such as the horizontal cross-sectional shape of the connecting groove 40, that is, a plurality of pillars are superposed. It is formed to have a horizontal cross-sectional shape.

The end portion of the seal kit 50 on the molding space 13 side has a locus aligned with the locus of the molding space 13, or is formed along the same locus as the end portion of the connecting groove 40 on the molding space 13 side. The cooling and heating passages 60 are formed at predetermined intervals from the end of the connecting groove 40 on the molding space 13 side.

At this time, since the shape of the bottom surface of the molding space 13 is extremely complicated, the formation depth of one vertical hole 41 of the connecting groove 40 and the subsequent vertical hole 41 is on the molding space 13 side of the connecting groove 40 and the seal kit 50. If the difference is larger than the separation distance of the ends, the flow path formed by the connecting groove 40 and the seal kit 50 may be blocked, but in this case, the formation depth of the vertical hole 41 of the connecting groove 40 or the seal kit 50 may be blocked. The height of each of the columns can be adjusted so that the cooling and heating passages 60 are formed as continuous passages.

Further, the seal kit 50 may form at least one seal protrusion 53 along the outer peripheral surface in order to improve the airtightness with the side surface of the connecting groove 40, that is, the mold body 31, and the seal protrusion 53 may be formed. Of course, a plurality of the above can be formed in the vertical direction.

On the other hand, the vertical holes 41 are not formed in an overlapping manner as described above, and the vertical holes 41 can be formed in a state of being separated by a predetermined interval. At this time, as shown in FIG. 3, it is preferable to process between the vertical holes 41 to form the connecting holes 42. It is desirable that the width of the connecting hole 42 is formed to be narrower than the diameter of the vertical hole 41 or to have a smaller diameter in order to minimize the machined portion, and to communicate between the vertical holes 41 by electric discharge machining.

At this time, the pillar portion 51 having the same cross section as the horizontal cross-sectional shape of the vertical hole 41 has a structure of being interconnected by the connecting portion 52 having the same horizontal cross-sectional shape as the cross section of the connecting hole 42.

On the other hand, when the thickness of the mold main body 31 of the lower mold 30 is relatively thick, as shown in FIG. 3, a retractable portion 32 having a predetermined depth can be recessed on the lower surface of the mold main body 31, and this retractable portion can be recessed. A cooling and heating passage 60 can be formed by recessing the connecting groove 40 from the side surface of the 32 molding space 13 on the 13 side and inserting the seal kit 50 into the connecting groove 40.

Then, on both side surfaces of the lower mold 30, a supply hole 43 and a discharge hole 44 for supplying and discharging the cooling fluid or the heating fluid to the cooling and heating passage 60 are communicated with one or more of the vertical holes 41, respectively. It is formed.

On the other hand, the cooling / heating unit 100 plays a role of supplying cooling water or hot water to the cooling / heating passage 60 to cool and heat the mold, and includes a heating unit 110 and a cooling unit 120.

The heating unit 110 passes through the boiler 111, the first circulation pipe 112 connecting the boiler 111 and the supply hole 43 to supply steam or hot water from the boiler 111 to the cooling and heating passage 60, and the cooling and heating passage 60. It is configured to include a second circulation pipe 113 connecting the boiler 111 and the discharge hole 44 in order to collect the steam or hot water discharged from the boiler 111.

At this time, the first circulation pipe 112 is provided with a first control valve 115 for interrupting the steam or hot water supply of the cooling and heating passage 60, and the second circulation pipe 113 is for storing condensed water. Condensed water tank 114 is provided.

The heating unit 110 is not limited to the above-described embodiment, and may be a heater provided on the side adjacent to the molding space 13. In this case, another first fluid passage (not shown) may be formed around the heater. The heater may be held by the seal kit 50 and installed adjacent to the molding space 13.

The cooling unit 120 is for cooling the molded product and the injection mold that have been molded by the molding space 13, and discharges the hot water supplied to the cooling and heating passages 60 using the cooling fluid and injects the molded product. Allow the mold to cool.

The cooling unit 120 supplies the cooling medium tank 121, which stores a cooling medium composed of cooling water or cooling oil, and the cooling medium tank 121, in order to supply the cooling medium of the cooling medium tank 121 to the cooling and heating passages 60. A third circulation pipe 123 connecting the hole 43 and a fourth circulation pipe 125 connecting the cooling medium tank 121 and the discharge hole 44 to collect the cooling medium discharged through the cooling and heating passage 60 are provided. At this time, the third circulation pipe 123 may further include a pump 124 for supplying a cooling medium. On the other hand, the cooling medium tank 121 is connected to the replenishment water tank 126 for replenishing the lost cooling medium. Then, a cooling system 122 for cooling the cooling medium may be installed in the cooling medium tank 121. Although not shown in the drawings, the cooling system 122 comprises a system driven by a normal refrigeration cycle having an evaporator and a condenser and a compressor.

The cooling unit 120 is not limited to the above-described embodiment, and any structure can be used as long as the mold can be cooled within a short time. For example, the cooling and heating passages 60 can be supplied with nitrogen for cooling, and thus a nitrogen tank and valve means for interrupting nitrogen may be provided.

In the present invention configured as described above, since the cooling and heating passages 60 can be formed inside the mold main body 31 of the upper mold 20 and the lower mold 30 so as to be adjacent to the molding space 13, the resin at the time of injection molding of the product. The heating and cooling times of the product can be shortened, and thus the injection molding cycle time of the product can be shortened to improve the productivity.

Further, in the present invention, each vertical hole 41 is machined, and a flow path is formed by the overlapping vertical holes 41. Therefore, the cooling and heating passage 60 can be easily designed in the molding space 13 having a complicated locus. be able to.

11: Lower fixing plate 12: Upper fixing plate 13: Molding space 20: Lower mold 21: Mold body 30: Upper mold 40: Connected groove 41: Vertical hole 42: Connecting hall 50: Seal kit 60: Cooling and heating passages