JP4431086B2 - Blow molding mold apparatus, resin hollow body manufacturing method using the blow molding mold apparatus, and resin hollow molded body manufactured by the manufacturing method - Google Patents

Description

  The present invention relates to a blow molding die device, a method for producing a resin hollow body using the blow molding die device, and a hollow molded body produced by the production method, particularly to a fuel tank of a vehicle. .

  As a fuel tank for automobiles, a resin tank is provided instead of metal because of the demand for weight reduction, and such a resin tank is obtained by blow-molding a thermoplastic resin such as polyethylene. In general, resin materials are easier to permeate volatile components such as gasoline than metals. Therefore, barrier layers with low permeability such as EVOH and nylon are usually provided on the inner and intermediate layers. Polyolefin and barrier material layers are molded in multiple layers. Resin tanks obtained in this way have been proposed (Patent Document 1, Patent Document 2).

  2. Description of the Related Art Generally, a fuel tank of an automobile is externally attached with a fuel filler port for supplying fuel from the outside, a return passage member for returning excess fuel from an engine, and the like. Furthermore, a wave-dissipating plate or the like is installed in the tank for the purpose of preventing the generation of abnormal noise due to liquid fuel shaking.

  In the case of molding a fuel tank or the like of an automobile that requires the incorporation of parts inside the hollow body with a resin in this way, conventionally, after shaping the outer shape of the tank by blow molding, a hole is formed in the hollow molded body. And a predetermined part was attached to the hole. Therefore, the conventional manufacturing method has a problem that a step of opening a hole is required, and the number of work steps is increased.

  In addition, since resin materials are more permeable to volatile components than metals, a barrier layer with low permeability such as EVOH (ethylene / vinyl alcohol copolymer) or polyamide is provided for use in fuel tanks. Since the parts do not have a barrier layer inside, there is a problem that volatile gas such as gasoline permeates through the parts.

  Here, it is possible to prevent the gas permeability by providing a barrier layer on a component to be attached later, but even in that case, there is no barrier layer at the welded portion between the component and the hollow molded body. However, the gas barrier property is not sufficient, and there is a problem that gas permeates.

  In addition, in order to install a wave-dissipating plate inside a hollow molded body such as a fuel tank, the tank wall itself can be recessed inward, and the recessed wall portion can be used as a wave-dissipating plate. However, since the recessed part which became depressed became thin, there existed a problem that the whole thickness had to be raised and the weight increase was caused.

Patent Document 2 proposes a resin fuel container in which injection-molded halves are brought into contact with each other and welded together. However, the invention of Patent Document 2 has a problem that the thickness of the hollow body becomes non-uniform by hollow blow molding, and an injection molded body having a uniform thickness is formed and joined to form a hollow body. Regarding the method. There is no disclosure of the technical idea of assembling a member inside the halved body, or joining and integrating the inner surface after modifying or processing the inner surface. In addition, since the separately molded halves are integrated later, the innermost layer needs to be a barrier layer so that the barrier layer is not interrupted at the joint surface. When the hollow molded body is subjected to a drop impact, the innermost layer that receives the most stress is likely to be destroyed, but EVOH and polyamide are generally inferior in impact resistance to polyolefins, so that the configuration using the innermost layer as a barrier layer is disadvantageous. there were. In addition, a number of processes are required in which the halved body is injection-molded, detached from the mold, the halved body is opposed, the welded portion is heated and melted, and butt-joined. Since it was necessary to reheat and melt the welded part of the injection-molded split body, the energy efficiency was also poor. Therefore, there has been a demand for a method for producing a hollow molded body in which permeation of volatile components is suppressed using a conventional hollow blow molding apparatus.

Patent Document 3 discloses a method for cutting an extruded parison. However, in the method of Patent Document 3, it is necessary to cut a thick parison before blowing, so that cutting may be difficult particularly for a parison composed of multiple layers. Further, since the parison is blown again after being welded, the welded portion is not blow-stretched, and the thickness of the hollow molded body becomes uneven.
JP-A-55-163134 JP-A-10-157738 JP 2002-103427 A

  In view of such circumstances, the present invention can be easily mounted at a predetermined position when a predetermined part is mounted inside a hollow molded body by blow molding, and contains a volatile liquid therein. It is an object of the present invention to provide a blow molding die apparatus used for molding a hollow molded body that can be used.

Another object of the present invention is to provide a production method suitable for producing a resin hollow molded article having good gas component barrier properties using this blow molding die apparatus.
Another object of the present invention is to provide a resin hollow molded body that can prevent leakage of volatile components as much as possible, particularly a vehicle fuel tank.

The mold apparatus for blow molding according to the present invention is:
A pair of main molds 2 and 4 that constitute a cavity that can be divided inside by closing the open end faces 2a and 4a of each other;
The first position or the open end surface 2a is disposed outside the pair of main molds 2 and 4 and the butted portions 12c and 12d protrude outward from the open end surfaces 2a and 4a of the main molds 2 and 4. , 4a, and a pair of slide molds 12a, 12b that move between the second position located inwardly ,
It is characterized in that the width of the butting portions 12c and 12d of the slide molds 12a and 12b is 5 mm or less .

According to such a mold apparatus, a hollow molded body can be obtained by mounting a parison in an internal cavity, closing the mold, inflating with gas, and then opening the mold .

If the width of the butt portion is in such a range, the hollow molded body can be easily divided when the mold is opened .

Each step is performed at a temperature at which the resin hollow body has plasticity that can be divided and welded, and is preferably performed at a temperature equal to or higher than the softening temperature of the thermoplastic resin.
Furthermore, it is preferable to use the said metal mold | die for the manufacturing method of the resin-made hollow bodies which concern on this invention.

That is, a method for producing a resin hollow body using the blow molding die device according to claim 1, wherein the resin hollow body production method using the blow molding die device according to the present invention is:
A pair of main molds 2 and 4 that constitute a cavity that can be divided inside by closing the open end faces 2a and 4a of each other;
The first position or the open end surface 2a is disposed outside the pair of main molds 2 and 4 and the butted portions 12c and 12d protrude outward from the open end surfaces 2a and 4a of the main molds 2 and 4. , 4a and a second position located inward, a pair of slide molds 12a, 12b, and a method for producing a resin hollow body using a blow molding die device comprising:
With the butted portions 12c and 12d in the first position protruding outward from the opening end faces 2a and 4a, a thermoplastic resin parison is blow-molded in a cavity in a separable mold to form a hollow molded body. A process of obtaining (assuming that the parison is not cut into two or more before blow molding)
After the parison is blow-molded in the cavity in the separable mold, the process of opening the separable mold and dividing the hollow molded body is performed.
At least one component is attached to the inner surface of the divided hollow molded body and / or the inner surface of the divided hollow molded body with the butted portions 12c and 12d being in either the first position or the second position. The process of modifying
With the butted portions 12c and 12d being in a second position located inward of the opening end surfaces 2a and 4a, a step of welding the hollow bodies divided by closing the mold to obtain an integrated hollow body It is characterized by doing.

Moreover, the manufacturing method of the resin hollow body according to the present invention includes a pair of main molds 2, 4 constituting a cavity that can be divided inside by closing the open end faces 2a, 4a to each other,
The first position or the open end surface 2a is disposed outside the pair of main molds 2 and 4 and the butted portions 12c and 12d protrude outward from the open end surfaces 2a and 4a of the main molds 2 and 4. , 4a and a second position located inward, a pair of slide molds 12a, 12b, and a method for producing a resin hollow body using a blow molding die device comprising:
The thermoplastic resin parison 6 extruded in a tube shape is sandwiched between the cavities of the pair of main molds 2 and 4, and the slide molds 12 a and 12 b are inserted from the opening end surfaces 2 a and 4 a of the main molds 2 and 4. A parison clamping step 10 in which the parison 6 is clamped by the butting portions 12c and 12d of the slide molds 12a and 12b by being arranged at the projecting first position;
The outer surface of the parison 6 and the main molds 2, 4 are attracted from the outside with respect to the parison 6 held by the butting portions 12 c, 12 d of the pair of slide molds 12 a, 12 b in the parison clamping step 10. In-mold suction step 15 for sucking between the inner surface of
The state before performing the in-mold suction step 15, the state after performing the in-mold suction step 15, and the same time as performing the in-mold suction step 15, A parison expansion step 20 for introducing gas and expanding the parison 6;
After the outer surface of the hollow molded body 6 expanded in the parison expansion process 20 is brought into close contact with the inner peripheral surface of the main molds 2, 4, a pair of main molds 2, together with the half-shaped hollow molded bodies 6a, 6b. A primary mold opening step 30 for opening 4;
Incorporating predetermined parts 32, 34, etc., which are separately formed in advance, on the inner surfaces of the hollow molded bodies 6 of the pair of main molds 2, 4 separated from each other in the primary mold opening step 30 Step 40,
After the predetermined parts 32 and 34 are assembled on the inner surface of the hollow molded body 6 in the main molds 2 and 4 in the part assembling step 40, the pair of main molds 2 and 4 are closed again. Secondary mold closing step 50;
A re-fusion step 60 for joining the butted surfaces of the half-shaped hollow molded bodies 6a, 6b, which are closed in the secondary mold closing step 50;
A secondary mold opening step 70 for taking out the product of the hollow formed body integrated in the re-fusion step 60 from the main molds 2 and 4;
In a state where the abutting portions 12c and 12d of the slide mold are in a first position protruding outward from the opening end faces 2a and 4a of the main molds 2 and 4, the parison clamping process 10 and the in-mold suction process 15 are performed. And each process of the parison expansion process 20 and the primary mold opening process 30 is performed,
In a state where the abutting portions 12c and 12d of the slide mold are in a second position located inward of the opening end faces 2a and 4a of the main molds 2 and 4, the secondary mold closing step 50 and re-fusion Each step of step 60 is performed.

According to the present invention including such a process, it is possible to attach a part to the inside during the hollow blow molding process, and therefore a process of opening a hole for attaching the part after molding becomes unnecessary. In addition, since the barrier layer is not interrupted at the component mounting portion, sufficient airtightness can be ensured. The gas introduced in the parison expansion process is preferably compressed air.
Here, in the present invention, it is preferable that the width of the abutting portions 12c and 12d of the slide molds 12a and 12b of the blow mold apparatus is 5 mm or less.

Furthermore, the hollow molded body according to the present invention is characterized by being manufactured by a method for manufacturing a resin hollow body including the above-described steps.
A hollow molded body manufactured by such a method, particularly a fuel tank of an automobile, has sufficient barrier performance and can prevent leakage of gas components rich in volatility as much as possible. It can be easily manufactured using a hollow molding apparatus.

  According to the method for manufacturing a resin hollow molded body using the blow molding die device according to the present invention, the process itself of closing the hole formed in the resin hollow molded body by welding or welding is eliminated. Good properties. In addition, since there is no welded portion or welded portion for sealing the hole, leakage of gas components can be effectively prevented even when highly permeable gasoline or the like is accommodated in the hollow formed body. be able to.

  Furthermore, the hollow molded body manufactured by such a method, in particular, a fuel tank for automobiles is lightweight and suitable for housing a highly permeable fuel such as gasoline.

  Hereinafter, a method for producing a resin hollow body according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing the steps of a method for producing a resin hollow body according to the present invention. Moreover, FIG. 2 is sectional drawing of the metal mold | die for implementing this manufacturing method.

  The method for producing a resin hollow body according to the present invention basically includes that a thermoplastic resin such as polyethylene is first plasticized by an extruder to obtain a tube-shaped parison, and then the parison before being cooled and solidified. Is inserted into the mold and then air is introduced into the parison. After that, the mold is once separated, the part is assembled in the half-divided parison (hollow molded body) in the mold using the open space, the mold is again abutted, and re- The product is obtained by fusing.

In addition, in this specification, the state after blowing a tube-shaped parison with compressed air etc. is made into a hollow molded object.
In addition, although the use in particular is not limited, the hollow molded object manufactured by this invention is a fuel tank, for example. It may be a fuel tank for an apparatus having an engine such as an automobile, a motorbike or a farm vehicle, and can be used for a fuel transport container, but it can be suitably used particularly for a fuel tank of an automobile. Accordingly, as shown in FIGS. 2 to 7, the inner surface of one mold 2 corresponds to the shape of the bottom of the fuel tank, and the inner surface of the other mold 4 has the shape of the upper portion of the fuel tank. It corresponds. Further, in the molds 2 and 4, air suction passages 8 connected to the decompression means are formed in branches, respectively, and the inside of the cavities can be sucked substantially uniformly through the branch-like air suction passages 8. Has been. In addition, a mold 2 for holding both ends of the parison 6
4 are provided with slide molds 12a and 12b which are integral with each other, and these slide molds 12a and 12b are opened by the cylinder device or the like on the opening end surface 2a of the main molds 2 and 4, respectively. 4a is movably attached to 4a.

  That is, the abutting portions 12c and 12d of the slide molds 12a and 12b project outward from the opening end faces 2a and 4a of the main molds 2 and 4, as shown in FIGS. 6 and 7, as shown in FIGS. 6 and 7, the main molds 2 and 4 are configured to be movable from the opening end faces 2a and 4a to a second position located inside.

The width a of the meshing portions of the main molds 2 and 4 is not particularly limited as long as the divided hollow molded body can be joined.
The abutting portions 12c and 12d of the slide molds 12a and 12b are formed in a spire shape and have a narrow width.

  Further, as shown in FIG. 8 in which the portion A shown in FIG. 3 is enlarged, the width b of the engagement portions 12c and 12d of the slide molds 12a and 12b is preferably 5 mm or less, and preferably 2 to 4 mm. More preferably, it is in the range. The gap d for forming the meshing portions 12c and 12d is preferably 10 mm or more.

  The thermoplastic resin used in the hollow body production method of the present invention is not particularly limited, but generally has a polyolefin layer and a barrier layer selected from EVOH or polyamide. A configuration in which the innermost layer and the outermost layer are made of polyolefin and the intermediate layer has a barrier layer is preferable from the viewpoint of maintaining the mechanical strength of the hollow body. Further, since the polyolefin layer and the barrier layer have poor adhesion, it is preferable to improve the adhesion by providing a modified polyolefin layer between the two layers. Examples of the modified polyolefin layer include polyethylene obtained by graft polymerization of a polar group monomer such as a polyvalent carboxylic acid.

  Polyethylene is preferable as the polyolefin, and high density polyethylene having a density in the range of 930 to 965 kg / m 3 can be suitably used. It is preferable that the MFR (melt flow rate) is in the range of 0.01 to 0.1 g / 10 min and the melting point is in the range of 120 to 135 ° C. EVOH is preferable as the barrier layer resin, and for example, EVAL (registered trademark) commercially available from Kuraray Co., Ltd. can be used.

Hereinafter, a manufacturing method for obtaining a resin hollow body such as a fuel tank of an automobile with such a mold will be specifically described.
The manufacturing method of the present invention includes a parison clamping process 10 that also serves as a primary mold closing process, an in-mold suction process 15 that sucks a space in a mold that sandwiches the parison, and a parison expansion process 20 that expands the parison. A primary mold opening step 30 for opening the pair of molds, a component assembling step 40 for mounting a predetermined part in the mold that has been opened, and a step of closing the pair of molds again. Secondary mold closing process 50, re-fusion process 60 for rejoining the butted portion of the half-divided tube, and secondary mold opening process for removing the integrally welded hollow formed body from the mold as a product 70.

  Then, as shown in FIG. 2, in the first parison clamping step 10, a pair of tube-shaped parisons 6 extruded to a predetermined length from a die head 1 provided in an extruder (not shown) are opened from each other. Passed between molds 2 and 4. At this time, the slide molds 12a and 12b are set to the forward movement position, that is, the first position. Thereafter, the mold is closed. Thereby, as shown in FIG. 3, the tube-shaped parison 6 is clamped by the butting portions 12c and 12d of the slide molds 12a and 12b.

  The temperature of the inner surface of the parison 6 when the mold is closed is 190 to 220 ° C., for example, 210 ° C. in the case of a multilayer parison composed of a polyethylene layer and an EVOH layer, and a pair of molds 2 and 4 and a slide mold 12a The temperature of 12b is preferably 5 to 40 ° C., preferably about 10 ° C.

  In this way, when the parison 6 is sandwiched between the molds 2 and 4, for example, an appropriate gas, for example, compressed air, is introduced into the parison 6 through the air nozzle 22 fitted in one mold 4. The parison 6 is expanded to obtain a hollow molded body 6. Thereafter, the inside of the molds 2 and 4 is sucked through the branch air suction passage 8 by driving the decompression means from the outside. The inside of the molds 2 and 4 may be sucked simultaneously with the introduction of the compressed air into the parison 6, or the inside of the molds 2 and 4 may be sucked before the introduction of the compressed air. . In this way, in the parison expansion process 20, as shown in FIG. 3, the slide molds 12a and 12b are in contact with each other, and the main molds 2 and 4 are not in contact with each other. The formed body 6 can be easily divided.

  In the present invention, the in-mold suction step 15 and the parison expansion step 20 are not limited in order, and may be performed in the reverse order or simultaneously, and the order is not limited at all. This in-mold suction step 15 can be omitted if the parison 6 or the hollow molded body 6 is not likely to fall from the molds 2 and 4 due to the size and shape of the product shape.

  The outer peripheral surface of the hollow molded body 6 in contact with the cooled inner wall surfaces of the molds 2 and 4 is immediately solidified, but the inner peripheral surface side of the hollow molded body 6 is still in a molten state. Under such a temperature environment, the shape of the fuel tank is substantially shaped as shown in FIG. The introduction time of the compressed air varies depending on the discharge amount of the compression pump and the capacity of the tank, but is usually about 5 seconds to 45 seconds, preferably about 30 seconds. The pressure of the compressed air is usually 3 to 15 kg / cm 2, preferably 4 to 6 kg / cm 2. A method of molding a parison extruded into a mold into a mold shape by a parison clamping process 10 that also serves as a primary mold closing process and a parison expansion process 20 that expands the parison is known. This is described in Japanese Unexamined Patent Publication No. 2004-160719.

  Thus, when compressed air is introduced into the parison 6 and expanded, the molds 2 and 4 are once opened as shown in FIG. The suction in the mold continues until the re-fusion process, and prevents the hollow molded body 6 shaped from the molds 2 and 4 from dropping off. In the primary mold opening process 30 of the molds 2 and 4, the outer surface of the hollow molded body 6 is substantially solidified by the cooled molds 2 and 4, and the inner circumference of the hollow molded body 6 is further increased. Since the surface is in a semi-molten state, if the molds 2 and 4 are separated from each other, the hollow molded body 6 is also separated into halves. When opening the mold, the hollow molded body 6 is easily divided because it is held only by the butting portions 12c and 12d of the slide molds 12a and 12b. When the half of the hollow molded body 6 cannot be easily divided, the temperature of the slide molds 12a and 12b is set higher than that of the main molds 2 and 4 so that the divided surfaces are not solidified. For example, it is preferably about 80 to 100 ° C. Alternatively, the cutting of the divided surface can be promoted by a cutter or the like.

  On the other hand, as shown in FIG. 5, separate members such as a valve 32 installed in a later step in the fuel tank or a wave-cancelling plate 34 for preventing the generation of abnormal noise are formed separately in advance. These separate members 32, 34, etc. are formed separately and then placed on a heater, etc. in another location, so that the contact surface side with the fuel tank is melted or semi-molten. I can keep it. Then, when the valve 32, the wave extinguishing plate 34 and the like whose contact surfaces are previously melted are prepared in this way, they are inserted into the divided molds 2 and 4 and arranged at predetermined positions of the hollow molded body 6. To do.

In addition, when performing the component incorporation step 40, in addition to component incorporation, the inner surface of the hollow molded body 6 is provided with an interior decoration such as applying a coating agent, applying unevenness, or applying a pattern. You can also.

  As shown in FIG. 5, after installing the interior member 32, the wave-cancelling plate 34, etc. at predetermined positions of the divided hollow molded bodies 6a, 6b, the slide molds 12a, 12b are moved backward, and the mold 2, 4 is closed. In this way, the preparation for rejoining in the re-fusion process 60 performed later is completed.

  As shown in FIG. 6, in the re-fusion process 60, the space between the molds 2 and 4 is closed, and compressed air is introduced again. At this time, the slide molds 12a and 12b are retracted to the second position described above. It is preferable that the time from when the hollow molded body 6 is extruded until the mold is closed in the secondary mold closing process 50 and the compressed air is introduced again is as short as possible. In order to join the hollow molded body 6 while maintaining a molten state, it is more desirable that it be within 100 seconds. Since the inner surface of the hollow molded body can be re-bonded for a short time before being cooled, the fusion strength of the re-joined portion of the main body can be kept high. In addition, since the valve 32, the wave extinguishing plate 34, and the like can be attached to the inside while the inner surface of the hollow molded body is in a molten state, it is possible to reliably integrate them. Then, as shown in FIG. 7, if the molds 2 and 4 are opened again after the hollow molded body 6 is cooled, a resin fuel tank can be obtained from the inside of the mold.

  As described above, according to the present invention, the work of opening a hole after blow molding is not required, and workability is good. Moreover, since the half-shaped hollow molded bodies are completely rejoined, the bonding strength of the hollow molded body can be kept high. Further, since the barrier layers are bonded to each other at the bonding surface as shown in FIG. 6, gas leakage can be reliably prevented.

  Such a fuel tank made of resin usually has a polyolefin layer and a barrier layer such as EVOH or nylon, and is preferably made of a resin having a six-layer structure. That is, HDPE (high density polyethylene), recycled resin, adhesive layer (for example, polyolefin copolymerized with polar monomers such as maleic acid), EVOH (ethylene / vinyl alcohol copolymer), adhesive layer (for example, maleic acid) Polyolefins copolymerized with polar monomers) and HDPE (high density polyethylene), and the thickness ratio can be appropriately changed, but is, for example, 13, 40, 2, 3, 2, 40%. Note that the recycled product is a waste material (burr) of the resin fuel tank collected after molding. If six kinds of such resins are prepared and each is extruded separately with an extruder, the layered resins come into contact with each other in a molten state, so that an integral six-layered hollow molded body 6 can be obtained. .

  A method for producing a multilayer blow molded article having a six-layer structure composed of HDPE / recycled resin / adhesive layer / EVOH / adhesive layer / HDPE will be specifically described in order from the outermost layer as described above. In addition, this is an example which shows the aspect of this invention, and the technical idea of this invention is not limited to this example.

  As the high density polyethylene, one having a density of 950 kg / m 3, an MFR of 0.03 g / 10 min, and a melting point of 131 ° C. is used. As the barrier layer resin, ethylene / vinyl alcohol copolymer / EVAL (registered trademark) commercially available from Kuraray Co., Ltd. is used. For the adhesive layer, polyolefin (Admer “registered trademark” manufactured by Mitsui Chemicals, Inc.) copolymerized with maleic acid, a polar monomer, is used.

  After extruding the multi-layer parison into the mold, a primary mold closing process is performed. The temperature of the parison 6 when the mold is closed is 200 ° C. The pair of molds 2 and 4 are cooled to around 10 ° C. The temperature of the slide molds 12a and 12b is 80 ° C.

When the parison 6 is sandwiched, compressed air is introduced into the parison 6 through the air nozzle 22 to expand the parison 6 to obtain the hollow molded body 6. The introduction time is about 30 seconds.
When compressed air is introduced into the parison 6 and expanded, the molds 2, 4 are sucked into the molds 2, 4 to prevent the hollow molded body 6 shaped from the molds 2, 4 from falling off. Open the mold once. Thereby, the hollow molded body 6 is also separated into halves.

The inner surface of the divided hollow molded body 6 is in a molten state, and another member such as a wave-cancelling plate 34 whose adhesive surface has been heated and melted in advance is disposed at a predetermined position of the hollow molded body 6 and attached thereto.
The slide molds 12a and 12b are retracted, and the molds 2 and 4 are closed again. After closing the mold, compressed air is introduced again, and the re-fusion process 60 is performed. The time from when the parison is extruded to when the mold is closed in the secondary mold closing process and the compressed air is reintroduced is 50 seconds. At this time, the temperature of the inner surface of the parison is about 160 to 190 ° C. The clamping pressure is 150,000 kg / cm 2 and the time is 60 seconds. During this re-fusion process, the innermost polyethylene layer is completely bonded, and the EVOH layer, which is a barrier layer, is also bonded, so that the bonding strength of the main body is kept high and the permeation of volatile components is prevented. Obtainable.

The manufacturing method according to the present invention has been described above, but the present invention is not limited to the above-described embodiment.
For example, in the above-described embodiment, an example in which the present invention is applied to a fuel tank of an automobile has been described. However, a hollow molded body can be manufactured in the same manner even if it is other.

FIG. 1 is a chart showing the steps of the manufacturing method of the present invention. FIG. 2 is a mold layout diagram of the parison clamping process, which is the first process according to the manufacturing method of the present invention. FIG. 3 is a mold layout diagram in the first half of the parison expansion process, which is the next stage of the parison clamping process of the manufacturing method. FIG. 4 is a mold layout diagram in the latter stage of the parison expansion process. FIG. 5 is a mold layout diagram in the primary mold opening process, which is the next stage of the parison expansion process, and the component assembling process subsequent thereto. FIG. 6 is a mold layout diagram in the secondary mold closing process, which is the next stage of the component assembling process, and the subsequent re-fusion process. FIG. 7 is a mold layout diagram in the secondary mold opening process which is the next stage of the re-fusion process. FIG. 8 is an enlarged view of a portion A shown in FIG.

Explanation of symbols

2,4 Mold 6 Parison (Hollow molding)
10 Parison clamping process (primary mold closing process)
12a, 12b Slide mold 15 In-mold suction process 20 Parison expansion process 22 Air nozzle 30 Primary mold opening process 40 Parts assembly process 50 Secondary mold closing process 60 Re-fusion process 70 Secondary mold closing process

Claims (4)

A pair of main molds (2), (4) constituting a cavity that can be divided inside by closing the mutual opening end faces (2a), (4a),
While being arranged outside the pair of main molds (2), (4), the butted portions (12c), (12d) are open end faces (2a) of the main molds (2), (4), A pair of slide molds (12a), (12b) that move between a first position protruding outward from (4a) or an open end face (2a), to a second position positioned inward from (4a); , equipped with a,
Blow molding mold apparatus in which the widths of the butted portions (12c) and (12d) of the slide molds (12a) and (12b) are 5 mm or less . A pair of main molds (2), (4) constituting a cavity that can be divided inside by closing the mutual opening end faces (2a), (4a),
While being arranged outside the pair of main molds (2), (4), the butted portions (12c), (12d) are open end faces (2a) of the main molds (2), (4), A pair of slide molds (12a), (12b) that move between a first position protruding outward from (4a) or an open end face (2a), to a second position positioned inward from (4a); , A method for producing a resin hollow body using a blow molding die device comprising:
A parison of a thermoplastic resin in a cavity in a separable mold with the butted portions (12c) and (12d) in a first position protruding outward from the opening end faces (2a) and (4a). A step of blow molding to obtain a hollow molded body (assuming that the parison is not cut into two or more before blow molding)
After the parison is blow-molded in the cavity in the separable mold, the process of opening the separable mold and dividing the hollow molded body is performed.
At least one component is attached to the inner surface of the divided hollow molded body and / or the divided hollow with the butted portions (12c) and (12d) in either the first position or the second position. A process of modifying the inner surface of the molded body,
With the butted portions (12c) and (12d) in the second position located inward of the opening end faces (2a) and (4a), the mold is closed and the divided hollow bodies are welded together. A method for producing a hollow resin body, characterized in that a step of obtaining a hollow body is performed. A pair of main molds (2), (4) constituting a cavity that can be divided inside by closing the mutual opening end faces (2a), (4a),
While being arranged outside the pair of main molds (2), (4), the butted portions (12c), (12d) are open end faces (2a) of the main molds (2), (4), A pair of slide molds (12a), (12b) that move between a first position protruding outward from (4a) or an open end face (2a), to a second position positioned inward from (4a); , A method for producing a resin hollow body using a blow molding die device comprising:
A thermoplastic resin parison (6) extruded in a tube shape is sandwiched between cavities of a pair of main molds (2) and (4), and the slide molds (12a) and (12b) are inserted into the main mold. (2), (4) By arranging at the first position protruding from the opening end faces (2a), (4a), the abutting portions (12c), (12d) of the slide molds (12a), (12b) A parison clamping step (10) for clamping the parison (6)
In the parison sandwiching step (10), the parison (6) sandwiched between the butting portions (12c) and (12d) of the pair of slide molds (12a) and (12b) by the suction means from the outside In-mold suction step (15) for sucking between the outer surface of the parison (6) and the inner surface of the main mold (2), (4);
The state before performing the in-mold suction step (15), the state after performing the in-mold suction step (15), and the same as performing the in-mold suction step (15), A parison expansion step (20) for introducing gas into the parison (6) and expanding the parison (6);
After the outer surface of the hollow molded body (6) expanded in the parison expansion step (20) is brought into close contact with the inner peripheral surface of the main molds (2) and (4), a half-shaped hollow molded body (6a) , (6b) and a primary mold opening step (30) for opening the pair of main molds (2), (4);
On the inner surfaces of the hollow molded bodies (6) of the pair of main molds (2) and (4) separated from each other in the primary mold opening step (30), predetermined parts ( 32), (34) and the like component mounting step (40),
After the predetermined parts (32), (34) and the like are incorporated into the inner surface of the hollow molded body (6) in the main molds (2), (4) in the part assembling step (40), the pair is again formed. A secondary mold closing step (50) for closing the main molds (2), (4) of
A re-fusion process (60) for joining the butt surfaces of the half-shaped hollow molded bodies (6a) and (6b) closed in the secondary mold closing process (50);
A secondary mold opening step (70) for taking out the product of the hollow forming body integrated in the re-fusion step (60) from the main molds (2), (4),
In a state where the butted portions (12c) and (12d) of the slide mold are in the first position protruding outward from the opening end faces (2a) and (4a) of the main molds (2) and (4), Perform each of the parison clamping step (10), the in-mold suction step (15), the parison expansion step (20), and the primary mold opening step (30),
In a state where the butting portions (12c) and (12d) of the slide mold are in the second position located inward from the opening end faces (2a) and (4a) of the main molds (2) and (4), A method for producing a resin hollow body, comprising performing each step of a secondary mold closing step (50) and a re-fusion step (60). A hollow molded body produced by the method for producing a resin hollow body according to claim 2 .

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