JPH011517A - Blow molding method for hollow molded products integrally molded with interior parts - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a blow molding method for a hollow molded product in which internal parts such as a baffle plate are integrally molded.

2. Description of the Related Art For example, when manufacturing a hollow molded product such as a plastic fuel tank, a method of integrally molding interior parts installed inside the tank is sometimes adopted.

An example of this molding method will be described in the case where a baffle plate is used as an interior component.

The baffle plate mentioned above is intended to improve the mechanical strength of the product and stabilize the volume of the molded product, as well as to partition the internal space in order to prevent abnormal noises caused by the movement of fuel, etc. while the vehicle is running. be.

Conventionally, the blow molding method for plastic hollow molded products with a baffle plate integrally molded inside the eel involves heating and melting thermoplastic resin such as polyethylene, polypropylene, polycarbonate, vinyl chloride resin, ABS resin, etc. A parison 6 of a predetermined length is molded by extrusion from the mold gap A between the core 4 and the die 5 (see Fig. 16) of the pro-molding machine,
This parison 6 is placed in one mold 2 as shown in FIG.
After the molds are clamped from left and right as shown in the figure by a pair of molding molds 1.2 each having a jetty portion 22L, the parison 6 is expanded by blowing air into the inside of the parison 6, and the molding molds 1.2 are expanded.
After cooling, the mold 1.2 was opened and the hollow molded product 3 was taken out (Japanese Patent Laid-Open No. 55-20157
(see publication).

In this way, a part of the parison 6 is pressed against the outer peripheral surface of the jetty portion 2a, and a baffle plate 3a is formed in the internal space B.

Note that FIG. 17 shows cooling holes drilled in the molding die 1.2.

Problems to be Solved by the Invention However, in the conventional blow molding method for a hollow molded product in which a baffle plate is integrally molded inside, the baffle plate is molded from the same parison as the hollow molded product. There was a problem in that the elongation rate of the parison in the baffle plate portion was much larger than the elongation rate in other parts, making the wall thickness after molding unstable and making it difficult to set the molding conditions.

In addition, in cases where the baffle plate is required to have a different thickness from other parts, it is extremely difficult to set the molding conditions, and the ratio of the baffle part to the total content of the hollow molded product increases, resulting in a decrease in internal capacity. There was also the drawback that it decreased.

Furthermore, in terms of appearance, grooves are formed in the baffle plate part, and depending on the molding conditions, wrinkles may occur on the outer surface.
There was a risk that the aesthetic appearance would be impaired.

Therefore, the present invention provides a blow molding method for a hollow molded product in which interior parts are integrally molded, which is easy to mold and has little effect on external appearance quality.

Means for solving the problem The interior parts are suspended between a pair of molds by a lobe whose one end is fixed to the core of the blow molding machine, and the parison is extruded to surround the interior parts such as the lobe and baffle plate. , the molding die is clamped to integrally mold the interior component and the parison.

In addition, the supporting portion of the lobe for the core is cooled or insulated to prevent heat from the core from being transferred to the lobe.

The interior parts suspended from the core of the blow molding machine by the action lobes are housed inside the parison by extrusion molding, and part of the outer periphery of the interior parts is joined to the parison by clamping the molding die. Molded in one piece.

At the same time, the lobes supporting the interior parts are held between both walls of the parison by the pinch section of the molding die, and become integrated with the hollow molded product.

Furthermore, if the supporting portion of the lobe for the core is cooled or insulated during the above molding, heat on the core side is prevented from being transmitted to the lobe and adversely affecting the lobe.

Embodiments Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings, with the same reference numerals assigned to the same parts as in the conventional structure.

First, a first embodiment is shown in FIGS. 1 to 4.

FIG. 1 shows the molding preparation stage of the present invention, in which the core 4 of the blow molding machine and the floor part 8 of the blow molding machine provided below the core 4 or the plywood floor part on which the molding machine is placed are shown. , a plurality of hooks 9 are fixedly installed, and one end of a lobe 10 is fixed to each of the hooks 9.

Then, the other end of each lobe 8 is made in advance by extrusion molding or the like.
The baffle plate 11 is connected to a baffle plate 11 as an interior part formed into a character shape, and this baffle plate 11 is supported in the air from above and below by lobes 10.

Next, the heated and melted thermoplastic resin is poured through the conical mold gap A formed between the core 4 and die 5 of the blow molding machine.
A parison 6 is formed by extruding it to a predetermined length on the outer periphery surrounding the lobe 10 and baffle plate 11.

Here, baffle temporary 11 and this baffle board! Generally, it is desirable that the material of the lobe 10 supporting the parison 6 is the same as that of the parison 6 for integration after molding, but it does not necessarily have to be the same material as long as it can be integrated by molding.

Next, from the state shown in Figure 1, the molding process of the hollow molded product, in which a baffle plate is integrally molded inside using a molding die, is carried out in the second step.
This will be explained using the drawings and FIG.

With the baffle plate 11 stored inside the parison 6,
When the two-split molding molds 12 and 13 are gradually brought closer in the direction of the arrow as shown in FIG. .

When the pinch parts 12a and 13a of the molding die 12.13 pinch the rope IO and feed air into the internal space B in a clamped state in which they touch each other, the state shown in FIG. The rope IO, which is integrally molded inside and supports the baffle plate 11, is completely and easily integrated at the joint of the parison 6.

After cooling, the molds 12 and 13 are opened to complete a hollow molded product 20 with a high quality appearance as shown in FIG.

In the above embodiment, two ropes 8 are provided on the upper and lower sides to support the baffle plate 11, but the number of ropes 8 may be one or more depending on the shape and size of the baffle plate to be supported. Alternatively, three or more ropes may be provided. In some cases.

Further, the rope connecting the baffle plate to the floor portion may be omitted as appropriate. Furthermore, as a baffle plate, for example,
It is made by foam-molding gasoline-resistant resin into a sponge-like plate, or by intertwining fibers of fibrous metal (steel wool) or gasoline-resistant resin, etc., with each other. If you use something hardened into a plate shape, etc., it is possible to prevent the noise of liquid level fluctuation when the vehicle turns, etc.

Next, a second embodiment will be explained with reference to FIGS. 5 to 7.

In this embodiment, a rotating tank 21 is used as an interior component.

This turning tank 21 is designed to ensure that fuel can be sucked even when the remaining fuel amount is low when the vehicle is turning, etc. In this embodiment, as shown in FIG. A pair of joining ribs 21b are provided on the main body 21a.

That is, the bottom of the swirl tank main body 21a and the pair of joining ribs 2
When the ends of 1b are clamped from left and right by molding molds 12.13, they are joined to parison 6 (No. 5.6).
(see figure).

Also, do the interior parts rotate? ! 21 is the same as the second embodiment described above, so the same parts are given the same reference numerals and the explanation will be omitted.

Next, a third embodiment will be explained with reference to FIG. 8.9.

This embodiment uses a tube unit 31 as an interior component.

This tube unit 31 is made by integrating a vent tube 31a and a filler neck 31b, and since a part of the tube unit 31 protrudes to the outside (see Fig. 9), when molding, as shown in Fig. 8, The protruding portion is positioned below the lower edge of the parison 6 when it is suspended from the rope IO. And from that state, the above-mentioned point! As in the embodiment, molding is performed by clamping the molds 12 and 13 from the left and right sides.

The interior component is a tube unit 31, and since this is the same as the first embodiment described above except that the hanging position of this tube unit 31 is different, the same parts are given the same reference numerals and a description thereof will be omitted.

Also, the interior parts are the baffle plate 11. The present invention is not limited to the tube unit 3I, but can also be applied to various types of brackets such as those for mounting liquid level gauges.

Next, the fourth embodiment will be explained based on the to and it.

This embodiment, along with the fifth embodiment described below,
The supporting portion of the core 4 is protected from electric heat.

Since the core 4 is heated by its nature, the hook 9
The rope 10 may melt and be cut due to the thermal energy transferred to the rope.

Therefore, in order to prevent this, in this embodiment, a heat shielding wall 14 made of a heat insulating material is formed in the core 4 surrounding the supporting part of the rope IO, and a cooling medium 15 such as water or Freon gas is provided in the heat shielding wall 14. A passage 16 is provided.

Therefore, according to this embodiment, the rope 10 is
is not cut by heat, further improving molding reliability.

Next, a fifth embodiment will be described with reference to FIGS. 12 and 13.

In this embodiment, in order to prevent the rope 10 from being cut due to heat, a piece 1 made of insulating material is attached to the upper end of the rope 10.
7 is provided, and a metal bracket 18 is integrally fixed to the upper part of the piece 17.

A solenoid 19 is attached to the corresponding core 4, and the bracket 18 is magnetized and suspended by the solenoid 19.

Therefore, in this embodiment, the suspension function and mounting by the solenoid 19 and the bracket 18 can exhibit the insulation function by the piece 17, which has the advantage of preventing the rope IO from being cut due to heat and making automation possible. .

The heat shield wall 14 of the fourth embodiment and the passage 16 of the cooling medium 15 are combined around the solenoid 19 of the fifth embodiment (see Figures 14 and 15) to more reliably prevent the rope 10 from breaking. It is also possible to do so.

Effects of the Invention As described above, according to the present invention, the thickness of the molded product is stabilized compared to the conventional molding method in which interior parts such as baffle plates are molded by rolling out a part of the parison. This has the effect of making molding easier.

In addition, since the interior parts are pre-molded, the wall thickness can be set arbitrarily regardless of the thickness of the outer wall of the hollow molded product, and the volume of the interior parts does not have to be as large as in the past. This has the effect of increasing the internal capacity of the hollow molded product.

In addition, since no grooves or wrinkles appear on the outer surface, the outer FIAF
There is also the effect that products with good p-quality can be manufactured.

If the supporting portion for the core of the rope is cooled or insulated, it is possible to prevent the rope from breaking due to heat, thereby further improving molding reliability.

[Brief explanation of the drawing]

Figures 1 to 4 show the first embodiment, Figure 1 is a perspective view showing the preparation stage for molding, Figures 2 and 3 are sectional views showing the molding situation, Figure 4 is a perspective view of the product, Figure 5 Figures 7 to 7 show the second embodiment, Figures 5 and 6 are sectional views showing the molding situation, Figure 7 is a perspective view of the product, Figures 8 and 9 show the third embodiment, and Figure 8 is a cross-sectional view showing the molding situation. A perspective view showing the molding situation, FIG. 9 is a perspective view of the product, and FIG. 10 is a perspective view of the product.
Figure 11 shows the fourth embodiment, Figure 1θ is a sectional view of the main part, Figure 11 is an enlarged view of the
The figure shows the fifth embodiment, FIG. 12 is a sectional view of the main part, and FIG.
The figure is Figure 12 xl! FIG. 14 is a sectional view of a main part of another embodiment, FIG. 15 is an enlarged view of section xv in FIG. 14, and FIG. The t'r diagrams are a perspective view showing a preparatory stage for molding and a cross-sectional view showing a completed state of mold clamping, respectively, according to the prior art. 4...core, 6...parison, IO...rope,
If...Baffle plate (interior parts), 12.13...
Molding mold, 20...Hollow molded product. Figure 4 Figure 5 Ritsuha Figure 6 Figure 7 Figure 8 31b (31) Figure 9 Figure 10 @11 Figure 11 (21X31) Figure 12 Figure 13 Figure 11 (21X31) Figure 16 Figure 17

Claims (4)

[Claims] (1) The interior parts are suspended between a pair of molds by a rope with one end fixed to the core of the blow molding machine, the parison is pushed out to surround the rope and the interior parts, and the molds are clamped. A blow molding method for a hollow molded product integrally molded with an interior component, characterized in that the interior component and the parison are integrally molded. (2) A blow molding method for a hollow molded product integrally molded with an interior component according to claim 1, wherein the interior component is a baffle plate. (3) A blow molding method for a hollow molded product integrally molded with an interior component according to claim 1 or 2, wherein the supporting portion for the core of the rope is cooled. (4) A blow molding method for a hollow molded product integrally molded with an interior component according to claim 1 or 2, wherein the support portion for the core of the rope is insulated.