KR20170123460A - Injection molding apparatus for high pressure gas container and method for the same - Google Patents

Abstract

Provided is an injection molding apparatus for a storage container, which includes an upper mold and a lower mold coupled to the upper mold in to a pair and forming a cavity with the upper mold, wherein an ejector is formed on the lower mold for spraying gas between the lower mold and an injected material, so that a liner can be separated from the upper mold.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high pressure hydrogen storage container liner injection apparatus and method,

The present invention relates to a high-pressure hydrogen storage container liner injection apparatus and method, and more particularly, to an injection mold structure and method thereof for enhancing the ease of liner-to-liner bonding during injection of a divided liner constituting a composite material storage container storing a high- .

Gas storage containers are needed to store and discharge various types of gases as needed. In particular, since gas has a low storage density in the container, it is effective to store the gas at a high pressure, but it is exposed to the risk of explosion due to high pressure. In particular, the substitute fuel gas vehicle has a limited space for loading the storage container. Therefore, securing the safety while maintaining the storage pressure at the high pressure is the core of the technology.

Therefore, in order to withstand the high withstand pressure of the hydrogen gas, the composite container of such a fuel gas storage container should be reinforced with a non-rigid and non-rigid fiber reinforced composite material, and a liner for inserting gas tightness is inserted therein . Two hemispherical liner are joined together to form one storage container, and heat fusion technology is used, which is a technique to heat and bond the joints. In this case, the cross-sectional shape of the joint is a right angle.

In addition, fuel gas, especially hydrogen, is divided into three types according to the material of the liner, a type 3 container in which a metal liner such as aluminum is inserted, and a container 4 in which a high density polymer is inserted. Although Type 3 is relatively stable, it has a disadvantage of being expensive and deteriorating endothelium properties, however, the Type 4 container is relatively inexpensive and has excellent endothelial characteristics, but has a problem of stability such as poor hydrogen permeation and permeation resistance.

In the type 4 container, two liners can not be fused to each other due to the nature of the material, and two liners are fused by laser welding or vibration welding. The laser welding method is a method in which a liner is fused by heat generated by irradiating a fused surface with a laser beam.

In such a laser welding method, it is important that the wider the surface where the two liners are in contact with each other at the time of fusion, the more advantageous it is, and the junction end of the liner is formed as a peak.

Meanwhile, the production of the liner is mainly performed by insert injection molding. Insert injection molding means that a part such as a metal is inserted into a mold first and then the material is put into a mold to mold the product. When the liner is manufactured by insert injection molding, the liner may shrink at room temperature due to the nature of the liner material. As a result, the liner is attached to the lower mold and the liner is generally extracted from the lower mold. However, since the extraction mold pushes the liner out of the lower mold, the hem shape of the hemispherical liner has to be damaged.

Due to the occurrence of such a phenomenon, it is impossible to secure the most advantageous shape for the laser welding described above, and an additional process is inevitably required.

Korean Patent Publication No. 10-2014-0128038 (Apr. Korean Registered Utility Model No. 20-0434302 (Dec. 19, 2006)

Currently, the storage container produced by the type 4 liner is produced by fusing two hemispherical plastic liner injection products to form a single storage container.

The injection shape of the joint portion is very important because leakage of the internal gas may occur depending on the shape of the joint portion of the plastic liner and the quality of fusion at the time of fusion.

However, when the product is attached to the lower mold after the injection and the product is taken out, an external force is inevitably applied to the end of the liner because the take-out die pushes the end of the liner out. As a result, the ends of the liner are inevitably damaged and can not be taken out in a sharp form, which is the most suitable type for laser welding.

Further, when the two liner are fused with the laser, the liner ends are joined to each other, and two blunt liner ends are joined and abutted to form beads, thereby adding a separate bead removing process.

In order to solve this problem, the present invention proposes a mold structure and a method for extracting a liner from a mold while maintaining the shape of a joint most suitable for laser welding.

In order to accomplish the above object, according to a preferred embodiment of the present invention, there is provided a method of manufacturing a metal mold comprising a lower mold coupled to an upper mold and a pair of upper molds to form a liner-shaped cavity, And an ejector of a lower mold configured to be able to inject gas into the cavity.

Further, a storage container injection apparatus is further provided, wherein the upper mold further comprises a fixing device configured on the upper mold capable of fixing the nozzle part to the upper mold.

Further, there is provided a storage container injection apparatus further comprising a take-out portion formed in the upper mold so as to take out the injection material from the upper mold.

Further, the injection-molded article is a liner which is insert-injected with a nozzle boss part at the upper center.

Further, the storage container injection apparatus is characterized in that the cooling temperature of the upper mold is higher than the cooling temperature of the lower mold.

Further, the storage container injection apparatus is characterized in that the subtraction gradient of the lower mold is larger than the subtraction gradient of the upper mold.

Further, an end of the liner end forms an inclined surface toward the inside of the liner.

According to a preferred embodiment of the present invention, the nozzle boss portion is positioned between the upper mold and the lower mold, the injection of the liner is performed in the cavity between the upper mold and the lower mold, A step of injecting gas into the interface, a step of separating the upper mold and the lower mold, and a step of taking out the injection material from the upper mold.

Further, before the step of injecting the liner between the upper mold and the lower mold, the nozzle boss part is fixed by the fixing device on the upper mold. .

Further comprising the step of maintaining the cooling temperature of the upper mold higher than the cooling temperature of the lower mold before the air is introduced into the interface between the lower mold and the liner .

Further, before the step of taking out the liner from the upper mold, the fixing device of the upper mold is released to separate the upper mold and the nozzle boss part. .

According to the present invention, since the liner is taken out from the upper mold, the shape of the liner end can be prevented from being damaged.

Therefore, the tip, which is the most suitable form for laser welding, can be taken out in a sharp tapered shape, and the bonding performance is improved when the laser welding of nylon material is performed.

In addition, since the tip can not be taken out in the form of a tapered end, a separate process is required after laser welding. However, in this case, the process can be shortened because no additional process is required for the end.

Furthermore, problems such as deterioration of bonding performance of the container caused by the removal of the bead of the fused portion can be solved.

As a result, the bonding performance of the fused portion is improved and the possibility of gas leakage in the fused portion is reduced, so that stability of the entire storage container is improved.

FIG. 1 illustrates a state in which a pair of upper and lower dies are engaged with each other to inject a liner in a cavity between both dies, according to an embodiment of the present invention,
FIG. 2 shows another embodiment of the present invention in which the minus slopes of the shapes of the upper mold and the lower mold are different, and in particular, the minus slope of the lower mold is larger than the minus slope of the upper mold,
3 is a view showing that a lower mold shape at a position where a lower mold and a liner end contact with each other is formed to have an inclined surface that widens as it goes down,
FIG. 4 shows another embodiment of the present invention in which an upper mold and a lower mold are separated from each other. In this case, the ejector of the lower mold injects gas between the liner and the lower mold interface, However,
5 is a view showing a state in which a fixing device of an upper mold holds a nozzle boss portion of an injection mold after an upper mold and a lower mold are separated from each other,
FIG. 6 is a perspective view illustrating a state in which the fixing device is detached from the upper mold and the take-out portion of the upper mold advances in the state of FIG. 4 according to an embodiment of the present invention, and the upper mold and the nozzle boss are disengaged, Fig.

The present invention relates to a container for storing a high-pressure gas, and relates to a device comprising a nozzle boss portion (13) and a liner (14) which can be attached to one end of a storage container and a method of manufacturing the device.

The nozzle boss portion 13 and the liner 14 are integrated with each other so that the liner 14 is formed between the two dies 11 and 12 so that the nozzle boss portion 13 and the liner 14 are integrated (Hereinafter referred to as " injection molding "). In particular, the present invention relates to a container for storing a fuel gas of a vehicle, and can be an object of a storage container such as, for example, a type 4 fuel container.

Hereinafter, a storage container liner injection apparatus according to a preferred embodiment of the present invention will be described in detail with reference to the drawings. 1, according to the present invention, a lower mold 12, which is a pair of an upper mold 11 and an upper mold and includes a liner-shaped cavity between the upper mold and the upper mold, and a nozzle boss portion 13 ) Is presented.

In the upper mold 11, an upper mold can constitute a fixing device 16 capable of fixing the injection molding. Preferably, the fixing device 16 can be constituted by a cylinder, and the injection mold 17 can be fixed to the upper mold in a pin fixing manner. However, when fixing the injection mold 17 and the upper mold 11, if the liner itself is fixed to the upper mold without the nozzle boss part, the liner may be deformed, so that it is necessary to fix the nozzle boss part to the fixing device.

Further, on the upper mold 11, a take-out portion 18 for taking out the molded product 17 from the upper mold can be provided. The take-out portion 18 is located at the center of the upper mold 11 and the take-out portion 18 is moved forward to push out the nozzle boss portion 13 located at the center of the injection mold 17, (17) can be taken out.

In order to separate the lower mold 12 and the injection mold 17 from the lower mold 12 after the liner 14 is injected into the lower mold 12, An ejector, preferably an air ejector, for injecting gas at the interface between the mold 12 and the liner 14 may be provided. In the preferred embodiment of the present invention, the air outlet of the ejector is formed at the highest point of the lower mold. However, the position (15) of the ejector and the gas outlet may be any position And can be configured variably.

Further, the nozzle boss portion 13 may be separately prepared in advance and positioned between the upper and lower molds before the upper and lower molds are engaged. The nozzle boss portion 13 is preferably located at the center of the upper end of the lower mold and may be made of metal.

On the other hand, the liner 14 can be formed in the cavity between the upper mold 11 and the lower mold 12. The liner 14 and the nozzle boss 13 are integrated to form the injection mold 17 and the liner 14 of the injection mold 17 is integrated with the nozzle boss 13, The nozzle boss portion 14 and the nozzle boss portion 13 are not separated from each other and can behave in a single structure. The injection mold 17 in a preferred embodiment of the present invention may be a part forming a type 4 liner.

On the other hand, the cooling temperature of the upper mold 11 and the lower mold 12 may be different in cooling the injected liner. Preferably, the cooling temperature of the lower mold 12 may be lower than the cooling temperature of the upper mold 11. [ In a more preferred embodiment, the temperature of the upper and lower molds can be increased up to 200 ° C during the molding time of 3 minutes after the material is inserted. The cooling time for the mold separation is 120 ° C for the upper mold and 80 ° C .

In addition, at the point where the end of the liner is formed, the inclination of the lower mold and the upper mold can be differently formed so that the molded product can be easily taken out from the lower mold and easily attached to the upper mold.

Referring to FIG. 2, it is preferable that the lowering mold 31 of the lower mold is larger than the lowering slope 32 of the upper mold. According to this subtraction gradient, it is easy to take out the molded article 17 from the lower mold 12. However, since the upper mold 11 has a minus draft opposite to the take-out direction, it is difficult to take out the mold from the upper mold. However, since the molded article is shrunk by cooling after being taken out from the lower mold, it is possible to take out the molded article even when the direction of inclination of the upper mold is in a direction in which it is difficult to take out the molded article. However, the draft angle 32 of the upper mold should be determined in consideration of the degree of shrinkage of the injection molding.

FIG. 3 shows the shape of the liner end and the shape of the lower mold. The shape of the lower mold at the position where the lower mold and the liner end are in contact with each other can be formed to have the inclined surface 21. 3, the end of the liner end may have a sloped surface 21 having a pointed end. As a result, the liner may be injected in a form most suitable for laser welding so that the injection product 17 can be taken out .

Hereinafter, a method for injecting a storage container liner injection apparatus according to a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

In the injection method of the present invention, the nozzle boss portion 13 is previously manufactured and positioned between the upper mold 11 and the lower mold 12. In the upper mold 11, And fixing the part (13) to the upper mold (11). FIG. 1 shows a step in which the upper mold 11 and the lower mold 12 are engaged with each other, and the liner 14 is injected from the cavity between both the molds. As described above, the nozzle boss portion 13 is preliminarily manufactured and positioned between the two molds, and the nozzle boss portion 13 is fixed to the upper mold 11 by the upper mold fixing device 16, Can be maintained.

The liner 14 is cooled and cooled so that the injection mold 17 easily adheres to the upper mold 11 and is easily separated from the lower mold 12 during the cooling process, Can be different.

FIG. 4 shows the moment when the upper mold 11 and the lower mold 12 are separated, and the ejector of the lower mold injects gas between the liner and the lower mold interface. In addition, although FIG. 4 illustrates that the ejection port of the ejector is formed at the highest point of the lower mold, the ejection port position 15 of the ejector may be variable. The injected liner can be attached to the lower mold 12 by shrinkage. However, the ejector of the lower mold injects gas between the lower mold and the injected liner to form an interface between the injected liner and the lower mold. As a result, the air layer artificially formed between the lower mold and the injected liner prevents the liner 14 from adhering to the lower mold 12 when the upper mold and the lower mold are separated, so that the molded product 17 is separated from the lower mold without damage can do.

5 shows a state where the upper mold and the lower mold are separated from each other and then the fixing device 16 of the upper mold, preferably the cylinder, grips the nozzle boss portion 13 of the injection mold, Fig.

6 shows a state in which the fixing device 16 on the upper mold is detached and the molded product 17 attached to the upper mold by the take-out part 18 of the upper mold is taken out from the upper mold 11 Fig. Preferably, the injection mold can be taken out from the upper mold by pushing out the nozzle boss portion of the injection mold while advancing the take-out portion 18 of the upper mold.

The present invention is characterized in that the mold to be finally taken out of the molded article 17 is not the lower mold 12 but the upper mold 11. [ When the injection material is taken out by the take-out portion 18 of the upper mold, the take-out portion 18 pushes the upper end of the injection object, i.e., the nozzle boss portion 13, so that no force is applied to the end 21 of the liner The tip of the sharpened liner is not damaged. Therefore, when the molded article 17 is taken out from the lower mold and the upper mold, both ends do not exert an external force on the end of the liner, and consequently, the liner end shape having the best bonding performance as described above can be formed.

Finally, the structure and method of the injection mold described in the preferred embodiments of the present invention are not limited to the drawings and examples, and the structure of the upper mold and the lower mold, which can be taken out from the upper part to prevent the end of the liner from being damaged, Quot; and " having "

11: Upper mold
12: Lower mold
13: Nozzle boss part
14: Liner
15: Ejector gas outlet position
16: Fixing device on upper mold
17: Injection (liner and nozzle boss part)
18: An injection molding machine
21: Slope of the end of the liner
31: Subtraction gradient of the lower mold (toward the inner side of the lower mold)
32: Depth of the upper mold (in the upper mold inner direction)

Claims (11)

Upper mold;
A lower mold engaged with the upper mold and forming a cavity with the upper mold;
An ejector of a lower mold provided in the lower mold and configured to inject gas between the lower mold and the injection molding;
And a storage container injection device. The injection molding machine according to claim 1, further comprising: an injection mold fixing device on the upper mold;
Further comprising: The injection molding machine as claimed in claim 1, further comprising: a take-out part formed in the upper mold so as to take out the injection product from the upper mold;
Further comprising: The storage container injection apparatus according to claim 1, wherein the injection object is a liner injected with a nozzle boss portion at an upper center thereof. The storage container injection apparatus according to claim 1, wherein the cooling temperature of the upper mold is higher than the cooling temperature of the lower mold. The storage container injection apparatus according to claim 1, wherein a subtraction gradient of the lower mold is larger than a subtraction gradient of the upper mold. The method as claimed in claim 1, wherein an end of the liner end forms an inclined surface toward the inside of the liner;
And the storage container injection device. (a) the nozzle boss portion is positioned between the upper mold and the lower mold;
(b) injecting a liner in a cavity between the upper mold and the lower mold;
(c) injecting gas into the interface between the lower mold and the injection mold;
(d) separating the upper mold and the lower mold;
(e) extracting the injection material from the upper mold;
And a discharge port for discharging the storage container. The method according to claim 8, further comprising fixing the nozzle boss portion by the fixing device on the upper mold before the step (b). The method according to claim 8, further comprising, before the step (c), maintaining the cooling temperature of the upper mold higher than the cooling temperature of the lower mold. The method according to claim 8, further comprising, before the step (e), releasing the upper mold fixing device to separate the upper mold and the nozzle boss.

Images