Core mold for blow molding device

Abstract

The present invention relates to a core mold for a blow molding device, and more specifically, to a core mold for a blow molding device characterized by cooling the core part using air supplied during the blow process to prevent the core part from being heated by the high-temperature resin and reaching a temperature above a certain level when a liquid type resin (parison) for forming a container is supplied and applied to the surface of the core part. The present invention is characterized by the fact that when the core mold is pushed into the molding part and high-pressure air is supplied through the core mold, the parison applied to the surface of the core mold expands in the molding part and adheres to the inner surface of the molding part to form a container of a specific shape, the supplied air is supplied to the inside of the heating means installation part where a heater is installed, thereby cooling the core part where the parison is applied.

Description

Technology Field

[0001] The present invention relates to a core mold for a blow molding apparatus, and more specifically, to a core mold for a blow molding apparatus characterized by cooling the core portion using air supplied during the blow process to prevent the core portion from being heated by the high-temperature resin and reaching a temperature above a certain level when a liquid-type resin (parison) for forming a container is supplied and applied to the surface of the core portion. Background Technology

[0003] Generally, blow molding is the process of manufacturing various types of plastic containers by expanding a hollow parison using an air blow method.

[0004] The mold device for performing such blow molding is structured such that, as shown in the attached drawing Fig. 1, a parison molding mold (100) is installed to form a parison (P) and has a plurality of resin-coating hollow portions (110) having a parison shape, and on the other side of the base body (B), a container molding mold (200) is installed to form a hollow container and has a molding portion (210) of a specific container shape, and between the parison molding mold (100) and the container molding mold (200), a core mold assembly (300) is installed such that a core mold (330) is connected by a screw to enable disassembly and assembly.

[0005] In the blow molding device described above, the conventional core mold (330) circulates oil stored in an oil storage tank (400) using a motor (M) as shown in the attached drawing Fig. 2, and at this time, the oil is heated by a heater (H). When the oil temperature rises above a set temperature, it is cooled to a set temperature using a cooling device (C).

[0006] In order to heat the oil to a constant temperature inside the core mold (330) and recover the oil having the high temperature, a double oil pipe (350) is inserted into the pipe insertion groove (330a) inside the core mold (330) so that the core mold (330) forms a constant temperature due to the high temperature.

[0007] However, when the conventional core mold (330) is inserted into the hollow part (110) for resin coating during parison formation, high-temperature resin is supplied and high-temperature heat is transferred from the resin to the core mold (330), causing it to be heated to a temperature of 120~130°C or higher. Consequently, when blowing the parison formed on the surface, the temperature is high, causing the viscosity of the resin to change and resulting in a quality degradation phenomenon where the thickness of the container is formed differently and a problem of producing defective products arises.

[0008] Furthermore, when forming a parison, the end portion of the core mold (330), where high-temperature heat is first transferred from the resin, has a higher temperature than other parts and corresponds to the bottom of the container when forming the container, so it causes problems such as the bottom of the container rupturing or becoming thin. Prior art literature

[0010] Republic of Korea Patent Registration No. 2345257 The problem to be solved

[0011] The objective of the present invention, devised in consideration of the aforementioned conventional problems, is to provide a core mold for a blow molding apparatus characterized by cooling the core portion using air supplied during the blow process to prevent the core portion from being heated by the high-temperature resin and reaching a temperature above a certain level when a liquid-type resin (parison) for forming a container is supplied and applied to the surface of the core portion. means of solving the problem

[0013] The objective of the present invention described above is achieved by a method for cooling a core mold for a blow molding device, characterized in that when a core mold is pushed into a molding section and high-pressure air is supplied through the core mold, the parison coated on the surface of the core mold expands in the molding section and adheres to the inner surface of the molding section to form a container of a specific shape, and the supplied air is supplied to the inside of a heating means installation section equipped with a heater to cool the heating means installation section coated with parison.

[0014] The implementation of the cooling method of the present invention is achieved by a core mold for a blow molding device, characterized in that the core mold comprises: a core pin member formed integrally with a heating means installation part having a heating means installation groove formed therein, on which a parison is applied on the outer surface and a heater means is fitted and installed on the inner side, and a connecting part having a cooling air supply hole formed therein for supplying cooling air to the heating means installation groove, wherein a step is formed at the portion where the heating means installation part and the connecting part meet; and a core fixing block part into which the connecting part is inserted, the step engages, and which expands the parison applied to the heating means installation part.

[0015] The above-mentioned core fixing block portion forms an air supply hole for supplying high-pressure air and forms an air supply through hole on the inside that communicates with the air supply hole to uniformly supply air, and when a core pin (330-6) is inserted and coupled on the inner surface of the air supply through hole, a plurality of air induction grooves are formed at regular intervals to supply high-pressure air to the air induction space that forms an air inflow space between the core pin member and the core pin member to expand the parison, and a leakage expansion groove is formed at the end of the air induction groove; and a core body is characterized by being bolted to the core mold assembly and having a flange portion integrally formed with an outer surface of a protruding projection portion protruding from the surface centered on a central through hole into which a core pin member is inserted, and an air discharge groove formed on the surface.

[0016] The structure of the above-described core pin member is achieved by a core mold for a blow molding device, characterized in that a core part on which a liquid-type resin (parison) for forming a container is applied to the surface is formed, and an insertion rod part having a cooling air supply hole formed integrally therewith is formed, and a groove for installing a heating means is formed inside the core part and the insertion rod part, and cooling is achieved by moving and supplying air to the groove for installing the heating means through the cooling air supply hole, and a step is formed at the boundary between the core part and the insertion rod part so that when the insertion rod part is inserted into the air supply hole, it catches on the step, thereby restricting the insertion of the core pin.

[0017] The above-mentioned core pin member is achieved by a core mold for a blow molding device, characterized by comprising: a core body portion having a hollow portion formed for applying a liquid type resin (parison) to the surface for forming a container; a heating means installation member having a heating means installation groove formed on the inner side of a rod rod fitted into the hollow portion, wherein a head portion is formed at one end of the rod rod to close one end of the hollow portion of the core body portion, and a screw portion is formed on the outer surface of the opposite rod rod; and a connecting member having a coupling portion formed on the inner side that is coupled to the screw portion of the rod rod penetrating the hollow portion of the core body portion, a through hole formed through which the rod rod passes, and a cooling air supply hole provided to allow high-pressure air to be introduced into the hollow portion. Effects of the invention

[0019] The present invention is a useful invention that has effects such as cooling the core part using air supplied during the blow process to prevent the core part from being heated by the high-temperature resin and reaching a temperature above a certain level when a liquid-type resin (parison) for forming a container is supplied and applied to the surface of the core part. Brief explanation of the drawing

[0021] FIG. 1 is an illustrative diagram to explain the structure and operation of a general blow molding device. FIG. 2 is a perspective view showing the structure of a core mold for a conventional blow molding device. FIG. 3 is an exploded perspective view showing the structure of a core mold for a blow molding device according to the present invention. FIGS. 4a and 4b are cross-sectional views showing the structure and operation of a core mold for a blow molding device according to the present invention. FIG. 5 is an exploded perspective view showing the structure of a core mold for a blow molding device, showing the structure of another embodiment of the present invention. FIGS. 6A and 6B are cross-sectional views showing the structure and operation of a core mold for a blow molding device of FIG. 5. FIG. 7 is a cross-sectional view showing another embodiment of a structure capable of supplying cooling air in the same direction as the heating means (oil pipe and heater pipe). Specific details for implementing the invention

[0022] A preferred embodiment of the present invention will be described in detail below with reference to the attached drawings.

[0023] The main effect of the core mold for a blow molding device according to the present invention is that when the core mold (1) is pushed into the molding section and high-pressure air is supplied through the core mold (1), the parison coated on the surface of the core mold (1) expands in the molding section (200) and adheres to the inner surface of the molding section (200) to form a container of a specific shape, the supplied air is supplied to the inside of the heating means installation section (11) where a heating heater is installed, thereby cooling the core pin member (10) coated with parison.

[0024] Figure 3 of the attached drawings is an exploded perspective view showing the structure of a core mold for a blow molding device according to the present invention. The core mold (1) for a blow molding device according to the present invention is broadly composed of a core fixing block part (20) that is inserted into and coupled to a core mold assembly (300), and a core pin member (10) that is fitted into the core fixing block part (20), bolted to the core mold assembly (300), and has a parison applied to form a container.

[0025] The structure of the core fixing block part (20) is formed such that, as shown in the attached drawing Fig. 3, an air supply hole (24) for supplying high-pressure air is formed, and an air supply through hole (23) for uniformly supplying air is formed on the inner side in communication with the air supply hole (24). When a core pin member (10) is fitted and coupled to the inner surface of the air supply through hole (23), an air supply through hole (23) is formed between the core pin member (10) and the core body (21), and air guide grooves (23a) are formed at regular intervals to allow air to be supplied to the air supply through hole (23) to expand the parison, and a leakage expansion groove (23b) is formed at the end of the air guide groove (23a). The structure is bolted to the core body (21) and the core mold assembly (300), and the flange part (22) is integrally formed around the central through hole into which the core pin member (10) is inserted.

[0026] The structure of the above-described core pin member (10) is formed by a core part (12) on which a liquid type resin (parison) for forming a container is applied to the surface, and an insertion rod part (13) that is integrally fitted into an air supply hole (23). A heating means installation groove (11) into which an oil pipe (500) is fitted is formed inside the core part (12) and the insertion rod part (13). A step is formed at the boundary between the core part (12) and the insertion rod part (13), so that when the insertion rod part (13) is inserted into the air supply hole (23), it catches on the step, thereby restricting the insertion of the core part (12).

[0027] The core mold (1) for the blow molding device of the present invention having the structure as described above is formed by installing either a heater or an oil pipe in a heating means installation groove (11) formed on the inner side of a core pin (12) to form a container as shown in the attached drawing Fig. 4a, and then heating to 120~130℃ using the heater pipe or the oil pipe, and when the set temperature is reached, moving the core mold (1) of the present invention so that it is inserted into the resin coating hollow part (110), and when the core mold (1) is inserted into the resin coating hollow part (110), the molten resin is supplied into the resin coating hollow part (110) so that the resin is coated on the surface and a parison (P) is formed.

[0028] The air supplied through the air supply port (24) is supplied through both the air supply port (23) and the cooling air supply port (14). The air introduced through the air supply port (23) causes the core mold (1), formed on the outer surface of the core pin (12) by the parison (P), to rotate toward the molding section (210). When the rotated core mold (1) is pushed into the molding section (210) and high-pressure air is supplied through the core mold (1), the parison (P) applied to the surface of the core mold (1) expands in the molding section (210) and adheres to the inner surface of the molding section (210), thereby forming a container of a specific shape.

[0029] The core mold (10) operated as described above had a problem in that when it was inserted into the hollow part (110) for resin coating during parison formation, high-temperature resin was supplied and high-temperature heat was transferred from the resin to the core part (12) and heated to a temperature of 120~130℃ or higher, so when the parison formed on the surface was blown, the temperature was high and the viscosity of the resin changed, resulting in a decrease in quality and the mass production of defective products with different thicknesses of the container.

[0030] Furthermore, when forming a parison, the end of the core part (12), where high-temperature heat is first transferred from the resin, has a higher temperature than other parts and corresponds to the bottom surface of the container when forming the container, which causes the problem of the bottom of the container rupturing.

[0031] In order to improve these problems, the cooling of the core pin member (10) in the present invention must be examined in terms of the flow of air supplied at high pressure. As shown in the attached drawing Fig. 4b, when high-pressure air is supplied through the air supply hole (330-1a), the high-pressure air flows into the air supply through hole (23) inside the core body (330-1) into which the core pin member is inserted. The air that flows in moves along the air guide grooves (23a) formed at regular intervals, connecting the gap formed between the core pin member (10) and the inner surface of the air supply through hole (23), and then collides with the step of the core pin member (10) inserted into the air supply through hole (23) by means of the leakage expansion groove (23b) formed at the end. At this time, since the leakage expansion groove (23b) is formed on the surface of the protrusion, it is discharged between the step of the core pin member (10) inserted into the air supply through hole (23). The parison (P) applied to the surface of the core mold (1) expands in the molding section (210) and adheres to the inner surface of the molding section (210), thereby forming a container of a specific shape.

[0032] The air supplied through the air supply port (24) is supplied through both the air supply port (23) and the cooling air supply port (14). The air introduced through the cooling air supply port (14) is moved to the heating means installation groove (11) through the cooling air supply port (14) formed in the insertion rod part (13) which is integrally formed with the core part (12), thereby cooling the temperature of the heating means installation groove (11). As a result, the temperature of the core part (12) and the temperature of the heating means (oil pipe and heater pipe) are cooled, thereby improving the quality of the product.

[0033] The attached drawing Fig. 5 is an exploded perspective view showing the structure of a core mold (1a) for a blow molding device showing the structure of another embodiment of the present invention, and Figs. 6a and 6b are cross-sectional views of a core mold for a blow molding device having the structure of Fig. 5. The blow molding device (1a) having the structure of another embodiment is a structure broadly composed of a core fixing block part (20) that is inserted into and coupled to a core mold assembly (300) and a core pin member (10a) that is fitted into the core fixing block part (20), bolted to the core mold assembly (300), and has a parison applied to form a container.

[0034] As shown in the attached drawings FIG. 5 and FIG. 6a, the structure of the core fixing block part (20) is formed by creating an air supply hole (24) that supplies high-pressure air and, in communication with the air supply hole (24), an air supply through hole (23) that can uniformly supply air is formed on the inner side. When a core pin member (10a) is fitted and coupled to the inner surface of the air supply through hole (23), an air inflow space part (23) is formed between the core pin member (10a) and the core body (21), and multiple air induction grooves (23a) are formed at regular intervals to allow high-pressure air to be supplied to the air inflow space part (23) to expand the parison, with a leakage expansion groove (23b) formed at the end of the air induction groove (23a). The core body (21) is bolted to the core mold assembly (300) and is centered around the central through hole into which the core pin member (10a) is inserted. It is a structure in which the flange portion (22) is formed integrally.

[0035] As shown in the attached drawing Fig. 5, the structure of the core pin member (10a) comprises a core body part (10a-1) having a hollow part (10a-1-1) formed for applying a liquid type resin (parison) to the surface to form a container, a chamfered air guide surface (10a-2-6) formed on the outer surface of a rod rod (10a-2-1) fitted into the hollow part (10a-1-1), and a heating means installation groove (10a-2-4) formed inwardly for fitting a heating means, a head part (10a-2-5) formed at one end of the rod rod (10a-2-1) to close one end of the hollow part (10a-1-1) of the core body part (10a-1), and a connecting screw part (10a-2-2) formed on the outer surface of the rod rod (10a-2-1) opposite the head part. The structure is composed of a heating means installation member (10a-2) and a connecting member (10a-3) having a connecting portion formed on the inside that is coupled to a connecting screw portion (10a-2-2) of a rod (10a-2) that penetrates the hollow portion (10a-1-1) of the core body (10a-1), a through hole (10a-3-1) through which the rod (10a-2) penetrates, and a cooling air supply hole (10a-3-2) provided to allow high-pressure air to be introduced into the hollow portion (10a-1-1).

[0036] The operation of a blow molding device (1b) having the structure of another embodiment of the present invention having the above-described structure is as shown in the attached drawings FIG. 6a and 6b, in order to form a container, either a heater pipe using electricity or an oil pipe using oil is installed in a heating means installation groove (11) formed on the inner side of a rod (10a-2) penetrating a core body part (10a-1), and then heated to 120~130℃ using the heater pipe or oil pipe, and when the set temperature is reached, the core mold (1a) of the present invention is moved to be inserted into the resin coating hollow part (110), and when the core mold (1) is inserted into the resin coating hollow part (110), molten resin is supplied into the resin coating hollow part (110) so that the resin is coated on the surface and a parison (P) is formed.

[0037] When the above parison (P) is formed on the outer surface of the core body (10a-1), the core mold (1a) is separated and withdrawn, and the core mold (1a) on which the parison (P) is formed is rotated 180° toward the molding part (210). Then, the rotated core mold (1a) is pushed into the molding part (210), and high-pressure air is supplied through the core mold (1). The parison (P) that was applied to the surface of the core mold (1a) expands in the molding part (210) and adheres to the inner surface of the molding part (210), thereby forming a container of a specific shape.

[0038] When the core mold (1a) operating as described above is inserted into the resin coating hollow portion (110) during parison formation, high-temperature resin is supplied, and the head portion (10a-2-5) is heated by the high heat of the supplied resin, and the resin is coated on the surface of the core body portion (10a-1) to form a parison.

[0039] At this time, when forming the parison, the head portion (10a-2-5), to which high-temperature heat is first transferred from the resin, is heated to a high temperature, and the rod (10a-2-1) integrally equipped with the head portion (10a-2-5) is also heated. Meanwhile, a heater pipe using electricity or an oil pipe using oil is inserted and installed in the heating means installation groove (10a-2-4) inside the rod (10a-2-1), so the temperature is further transferred and becomes high. Therefore, since the head portion (10a-2-5) has a higher temperature than other parts and corresponds to the bottom surface of the container during container formation, it causes the problem of the bottom of the container rupturing.

[0040] In order to improve these problems, in another embodiment of the present invention as illustrated in the attached drawings FIG. 6a and 6b, the cooling of the core pin member (10a) must be examined through the flow of air supplied at high pressure. As illustrated in FIG. 6b, when high-pressure air is supplied through the air supply hole (24), the high-pressure air flows into the air supply through hole (23) inside the core body (20) into which the core pin member (10a) is inserted. The air that flows in moves along the air guide grooves (23a) formed at regular intervals, connecting the gap formed between the core pin member (10a) and the inner surface of the air supply through hole (23), and then collides with the step of the core pin member (10a) inserted into the air supply through hole (23), such as the step of the core body part (10a-1) and the connecting member (10a-3), due to the leakage expansion groove (23b) formed at the end. At this time, the Since the leakage expansion groove (23b) is formed on the surface of the protrusion, the parison (P) applied to the surface of the core mold (1) is discharged between the step of the core pin member (10) inserted into the air supply hole (23) and expands in the molding part (210) and adheres to the inner surface of the molding part (210) to form a container of a specific shape.

[0041] However, some of the supplied air is supplied to the air supply hole (23) through the cooling air supply hole (24) as shown in the attached drawing Fig. 6b, and the supplied low-temperature air is moved to the hollow part (10a-1-1) of the core body part (10a-1) through the cooling air supply hole (10a-3-2) formed in the connecting member (10a-3).

[0042] The low-temperature air transferred to the above-mentioned hollow section (10a-1-1) fills the space between the rod (10a-2-1) inserted and installed in the hollow section (10a-1-1), and at this time, a chamfered air-guiding surface (10a-2-6) is formed on the outer surface of the rod (10a-2-1) so that more air can be induced, thereby improving the cooling effect.

[0043] As described above, when the temperature of the core body (10a-1) and the heating means installation member (10a-2) is cooled, the temperature of the heating means (oil pipe and heater pipe) is cooled, thereby improving the quality of the product.

[0044] As shown in the attached drawings Fig. 3 and Fig. 5, cooling air can be supplied through the cooling air supply hole (10a-3-2) of the core pin member (10)(10a) and the cooling air supply hole (24) of the core fixing block part (20), but as shown in the attached drawing Fig. 7, air can also be supplied in the same direction as the heating means (oil pipe and heater pipe) installed on the core pin member (10)(10a) as a cooling method.

[0045] Therefore, the present invention is a useful invention that has effects such as cooling the core part using air supplied during the blow process to prevent the core part from being heated by the high-temperature resin and reaching a temperature above a certain level when a liquid-type resin (parison) for forming a container is supplied and applied to the surface of the core part.

Claims

Claim 1 delete Claim 2 A core pin member formed by integrally forming a heating means installation part having a heating means installation groove formed on the outer surface where a parison is coated and a heater means is fitted and installed on the inner side, and a connecting part having a cooling air supply hole formed to supply cooling air to the heating means installation groove, wherein a step is formed at the portion where the heating means installation part and the connecting part meet; A core mold for a blow molding device, characterized by a structure in which a step is formed at the boundary between the core and the insertion rod, and when the insertion rod is inserted into the above-mentioned connecting part and a step is engaged, the core fixing block part expands the parison applied to the heating means installation part; air supplied through the air supply hole is supplied through both supply holes, the air supply through hole and the cooling air supply hole; the air introduced through the air supply through hole rotates the core mold formed on the outer surface of the core part towards the molding part, pushes the rotated core mold into the molding part, and when high-pressure air is supplied through the core mold, the parison (P) applied to the surface of the core mold expands in the molding part and adheres to the inner surface of the molding part to form a container of a specific shape; and when the insertion rod is inserted into the air supply through hole, the step is engaged, thereby restricting the insertion of the core part. Claim 3 delete Claim 4 delete Claim 5 delete

Images