JP4095926B2 - Molding method of resin molding - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
In this invention, the core material is set in the upper mold, the upper mold and the lower mold are closed, and in this mold closed state, the molten resin material is injected into the cavity formed between the upper mold and the lower mold The present invention relates to a molding method for molding a resin molded body by a so-called closed injection method.
[0002]
[Prior art]
As a molding method for molding a resin molded body by the closed injection method as described above, the following molding method is disclosed (for example, see Patent Document 1).
[0003]
The molding procedure is as follows. First, the skin is set on the lower mold in the mold open state, and then the core material is placed thereon.
[0004]
Next, with the upper die and the lower die closed, a plurality of rods provided in the upper die so as to be able to advance and retreat in the vertical direction are advanced downward, and the engaging portion at the tip thereof is a cylindrical shape on the back surface of the core material A lock pin that is inserted into the rod so as to be able to advance and retreat in the vertical direction is advanced downward to project the engaging portion outward at the tip thereof, and into the cylindrical recess. Press contact engagement with the peripheral surface.
[0005]
Thereafter, the rod and the lock pin are integrally retreated upward, whereby the core material is pulled up and set on the molding surface of the upper mold.
[0006]
After that, the injection nozzle is inserted into the core material injection port from the upper mold insertion port, the molten resin material is injected from the injection nozzle into the cavity formed between the upper mold and the lower mold, and the resin layer is formed. Molding is performed to obtain a resin molded body in which a resin layer is integrally formed between the core material and the skin.
[0007]
[Patent Document 1]
Japanese Utility Model Publication No. 4-2007 (Page 2, Fig. 1)
[0008]
[Problems to be solved by the invention]
However, in the above-mentioned Patent Document 1, a dedicated pulling means (rod, lock pin, etc.) for pulling up the core material and setting it in the upper mold is necessary, so that the apparatus becomes complicated and the equipment cost increases.
[0009]
Further, since the lifting means is provided at a position away from the upper mold insertion port (core material injection port), even if the core material is pulled up by the folding means and the lifting means, If there is a gap between the set surface of the upper mold and the molten resin material is injected into the cavity in this state, the molten resin material leaks from the inlet to the back surface of the core material and the back surface of the core material and the upper mold are set. It is necessary to remove the resin adhering to the upper die and the productivity is reduced, and the core material is adhered to the set surface of the upper die with the leaking resin, making it difficult to remove the mold, which hinders the molding operation. Come.
[0010]
Therefore, it is considered that a sealing material such as urethane slab is attached around the inlet on the back surface of the core material, and the sealing material is impregnated so as not to adhere to the molding material surface of the core material back surface and the upper mold, Separately, the cost is increased by the amount required for the sealing material, and the extra work of sticking the sealing material is required, which reduces productivity.
[0011]
The present invention has been made in view of such a point, and an object of the present invention is to prevent the molten resin material from leaking out to the back side of the core material without causing an increase in equipment cost.
[0012]
[Means for Solving the Problems]
In order to achieve the above object, the present invention is characterized in that the injection nozzle has a core pulling function.
[0013]
Specifically, the present invention has taken the following solutions.
[0014]
That is, in the present invention, first, the core material is set on the set surface of the upper mold so that the back surface of the core material having the injection port faces the set surface of the upper mold, and then the upper mold and the lower mold are closed. The injection nozzle having the engagement portion formed on the tip side is lowered and inserted into the injection port of the core member, and the engagement portion is formed on the engagement portion formed on the inner peripheral surface of the injection port or the outer periphery of the injection port. After that, the injection nozzle is raised to bring the periphery of the injection port on the back surface of the core material into contact with the set surface of the upper mold, and then, a cavity formed between the upper mold and the lower mold A molten resin material is injected into the resin nozzle from the injection nozzle to form a resin layer, and a resin molded body in which the resin layer and the core material are integrally formed is obtained.
[0015]
With the above configuration, in the present invention, since the injection nozzle also serves as the core material pulling means, there is no need for a separate pulling means having a complicated structure, and the apparatus is simplified correspondingly and the equipment cost is reduced.
[0016]
In addition, since the injection nozzle is inserted into and engaged with the injection port of the core material, and the core material is pulled up by the injection nozzle, the periphery of the injection port on the back surface of the core material is completely in close contact with the set surface of the upper mold. There is no gap, and the molten resin material does not leak. Therefore, the leaked resin does not adhere to the upper mold in the vicinity of the injection port, thereby eliminating the need for removing the adhered resin and improving the productivity. Furthermore, there is no situation in which the core material is adhered to the set surface of the upper mold with a leaking resin and it is difficult to remove the mold, and the molding operation can be performed smoothly without any trouble. Further, a sealing material such as a urethane slab impregnated with a leaking resin is not required, and the cost is reduced correspondingly, and an extra work such as a sticking work of the sealing material is unnecessary, and productivity is improved.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a method for molding a resin molded body according to an embodiment of the present invention will be described with reference to the drawings.
[0018]
(Embodiment 1)
1 to 4 are process diagrams of a method for molding a resin molded body according to Embodiment 1 of the present invention.
[0019]
First, as shown in FIG. 1, a resin skin 101 preliminarily molded into a predetermined shape by, for example, vacuum molding or slush molding is placed on the set surface 3 a of the lower mold 3 of the mold 1, and the upper mold 5 The resin core material 103 is set on the set surface 5a, and the upper mold 5 and the lower mold 3 are closed. At this time, the core material 103 is set on the set surface 5a of the upper mold 5 so that the back surface of the core material 103 faces the set surface 5a of the upper mold 5, and an injection port 103a formed through the center of the core material 103 is provided. The upper die 5 is communicated with an insertion port 5b formed through the center of the upper die 5. In this closed state, a gap C is formed between the back surface of the core material 103 and the set surface 5a of the upper die 5 due to the deformation of the core material 103, molding errors, and the like. A cavity 7 is formed between the lower mold 3 and the upper mold 5. A support column 9 is erected in the vicinity of the insertion port 5 b on the upper surface of the upper die 5, and a fluid pressure cylinder 11 having a piston rod 11 a extending downward is installed at the upper end of the support column 9. An injection head 13 is connected to the lower end of the piston rod 11 a of the fluid pressure cylinder 11 via a slide member 15. The injection head 13 is guided while the slide member 15 is guided along the column 9 by the expansion and contraction operation of the fluid pressure cylinder 11. Is designed to move up and down. An injection nozzle 17 is suspended at the lower end of the injection head 13 so as to be rotatable about an axis by a rotating device 19 such as a motor. As shown in enlarged detail in FIG. 5, the injection nozzle 17 is formed with a resin passage 17 a, and a screw-like engagement groove 17 b as an engagement portion is formed on the distal end side of the injection nozzle 17. Yes. On the other hand, on the inner peripheral surface of the injection port 103a of the core member 103, a screw-like engagement protrusion 103b as an engaged portion protrudes.
[0020]
Next, as shown in FIG. 2, with the mold 1 closed as described above, the fluid pressure cylinder 11 is extended to lower the injection head 13 (injection nozzle 17), and the injection nozzle 17 is raised. The insertion port 5b of the mold 5 is inserted into the injection port 103a of the core material 103, the rotating device 19 is activated to rotate the injection nozzle 17 around the axis, and the engaging groove 17b is inserted into the injection port 103a. Engage with the engaging protrusion 103b on the peripheral surface.
[0021]
Thereafter, as shown in FIG. 3, the fluid pressure cylinder 11 is contracted to raise the injection head 13 (injection nozzle 17) slightly. Thereby, the core material 103 is pulled up by the injection nozzle 17, and the periphery of the injection port 103 a on the back surface of the core material 103 comes into contact with and closely contacts the set surface 5 a of the upper mold 5. Thereby, the gap C (see FIGS. 1 and 2) formed between the back surface of the core material 103 and the set surface 5a of the upper mold 5 is eliminated.
[0022]
Thereafter, as shown in FIG. 4, a molten resin material R such as hot melt resin or urethane foam resin is injected into the cavity 7 between the upper mold 5 and the lower mold 3 from the resin passage 17a of the injection nozzle 17. To do.
[0023]
Thereafter, the molten resin raw material R is solidified in the cavity 7 to form a resin layer (not shown), and a resin molded body 100 in which the resin layer, the skin 101 and the core material 103 on both sides thereof are integrally molded is obtained. Obtain (see FIG. 6).
[0024]
When the molded resin body 100 is molded in this manner, the injection nozzle 17 is rotated in the reverse direction around the axis by the activation of the rotating device 19 to disengage the engaging groove 17b from the engaging protrusion 103b, and thereafter Then, the fluid pressure cylinder 11 is contracted to raise the injection head 13 (injection nozzle 17) to be detached from the insertion port 5b of the upper mold 5, and then the mold 1 is opened to open the resin molded body 100. Demold from upper mold 5.
[0025]
Thus, in this Embodiment 1, the core material 103 is made into the state which engaged the engagement groove | channel 17b of the injection nozzle 17 with the engagement protrusion 103b of the injection port 103a inner peripheral surface of the core material 103. By pulling up, the back surface of the core material 103 is brought into close contact with the set surface 5a of the upper mold 5 without a gap C. Therefore, the injection nozzle 17 is provided with a dedicated pulling means having a complicated structure that also serves as a pulling means. The equipment cost can be reduced by simplifying the apparatus accordingly.
[0026]
Further, since the injection nozzle 17 is inserted and engaged with the injection port 103a of the core material 103 and the core material 103 is pulled up by the injection nozzle 17, the periphery of the injection port 103a on the back surface of the core material 103 is set to the set surface 5a of the upper mold 5. It can be made to adhere completely so that there is no gap C between them, and leakage of the molten resin raw material R can be prevented. Accordingly, the leakage resin can be prevented from adhering to the upper mold 5 in the vicinity of the inlet 103a, thereby eliminating the operation of removing the adhered resin and increasing the productivity.
[0027]
Furthermore, the core material 103 is bonded to the set surface 5a of the upper mold 5 with a leaking resin, so that it is difficult to remove the mold, and the molding operation can be performed smoothly without any trouble.
[0028]
Moreover, since it is not necessary to use a sealing material such as urethane slab impregnated with leaking resin, the cost can be reduced by that amount, and productivity can be increased by eliminating the extra work of sticking the sealing material. Can do.
[0029]
(Embodiment 2)
7 to 9 show the engagement relationship between the injection nozzle 17 and the core material 103 used in the method for molding a resin molded body according to Embodiment 2 of the present invention.
[0030]
That is, as shown in an enlarged detail in FIG. 7, the injection nozzle 17 has a pair of L-shaped engagement arms 21 as engagement portions 180 with the engagement claws 21 a at the tip facing downward and inward. ° It is integrally formed to project radially outward on the opposite side.
[0031]
On the other hand, as shown in an enlarged detail in FIG. 8, an injection tube portion 113 is integrally provided on the outer periphery of the injection port 103 a of the core material 103, and the injection tube portion 113 has an upper end as an engaged portion. The pair of engagement rods 113a are integrally formed to project radially outward on the opposite side of 180 °. The distance D1 between the two engaging rods 113a is the distance D2 between the inner surfaces of the front ends of the engaging arms 21 so that the engaging rods 113a can engage with the engaging claws 21a of the engaging arms 21 and rotate (see FIG. 7). ) Is narrower than. Further, on both sides between the pair of engaging rods 113a, linearly cut-out notches 113b are formed. The interval W1 between the notches 113b is narrower than the interval W2 (see FIG. 7) between the tips of the engagement claws 21a so that the engagement claws 21a of the engagement arm 21 can enter and exit.
[0032]
When the core material 103 is pulled up by the injection nozzle 17, first, as shown in an enlarged detail in FIG. 9A, both engagement arms 21 of the injection nozzle 17 are connected to both notches 113 b of the injection cylinder portion 113. As shown in FIG. 9B, the tip of the injection nozzle 17 is inserted into the injection port 103a of the core member 103, and then the injection nozzle 17 is rotated 90 ° around the nozzle center line. Then, both the engaging arms 21 are engaged with both engaging rods 113a of the injection tube portion 113, and the core member 103 is pulled up. Thus, the gap C between the back surface of the core material 103 and the set surface 5a of the upper mold 5 is eliminated, and the periphery of the inlet 103a on the back surface of the core material 103 is brought into close contact with the set surface 5a of the upper mold 5.
[0033]
Other than that, the configuration and the molding method are the same as those of the first embodiment, and thus the description of the overall configuration of the apparatus and the molding method throughout is omitted.
[0034]
Therefore, in the second embodiment, the same operational effects as in the first embodiment can be achieved.
[0035]
In this example, the case where the resin molded body 100 has a three-layer structure of the skin 101, the core material 103, and the resin layer is shown, but the present invention can also be applied to a resin molded body without the skin 101.
[0036]
【The invention's effect】
As described above, according to the present invention, the injection nozzle is inserted into the injection port of the core material, the engaging portion is engaged with the engaged portion on the core material side, and the core is moved by the upward movement of the injection nozzle. Since the periphery of the injection port on the back of the material is in contact with the set surface of the upper mold and the periphery of the injection port on the back of the core material is completely in close contact with the set surface of the upper mold, there is no need for a dedicated lifting device with a complicated structure. The equipment cost can be reduced. Furthermore, it is possible to eliminate the adhesion of the leaked resin to the upper mold in the vicinity of the injection port, thereby eliminating unnecessary resin removal work and improving the productivity. Further, there is no adhesion of the core material to the upper mold due to the leaked resin, and the mold can be removed easily and the molding operation can be performed smoothly. In addition, the cost can be reduced by eliminating the sealing material such as urethane slab impregnated with the leaking resin, and the productivity can be improved by eliminating the extra work of sticking the sealing material.
[Brief description of the drawings]
FIG. 1 is a process diagram showing a state in which a skin and a core material are set on a set surface of a mold and the mold is closed in the molding method according to Embodiment 1 of the present invention.
In the molding method according to Embodiment 1 of the present invention, the injection nozzle is lowered and inserted into the injection port of the core material, and the engagement groove groove of the injection nozzle is engaged with the engagement protrusion on the inner peripheral surface of the injection port. It is process drawing which shows the state engaged with the strip.
FIG. 3 is a process diagram showing a state in which the injection nozzle is raised and the back surface of the core material is brought into contact with the set surface of the upper mold in the molding method according to Embodiment 1 of the present invention.
FIG. 4 is a process diagram showing a state in which a molten resin material is injected into a cavity of a mold in the molding method according to Embodiment 1 of the present invention.
FIG. 5 is an enlarged view of the engaging portion between the injection nozzle and the core material injection port of the molding apparatus used in the molding method according to Embodiment 1 of the present invention;
FIG. 6 is a perspective view of a resin molded body.
7A and 7B show an injection nozzle used in a molding method according to Embodiment 2 of the present invention, wherein FIG. 7A is a bottom view and FIG. 7B is a longitudinal sectional view of FIG.
8 shows an injection tube portion of a core material used in a molding method according to Embodiment 2 of the present invention, (a) is a plan view, (b) is a cross-sectional view taken along line AA in (a), (C) is sectional drawing in the BB line of (a).
FIGS. 9A and 9B show process diagrams of a molding method according to Embodiment 2 of the present invention, in which FIG. 9A shows a state where an injection nozzle is inserted into an injection port of a core material, and FIG. In this state, the core member is pulled up by being engaged with the engagement rod of the cylindrical portion.
[Explanation of symbols]
3 Lower mold 5 Upper mold 5a Set surface 7 Cavity 17 Injection nozzle 17b Engaging groove (engaging part)
21 engaging arm (engaging part)
100 resin molded body 103 core material 103a inlet 103b engagement protrusion (engaged part)
113a engagement rod (engaged part)
R Molten resin raw material

Claims (1)

Set the core material on the set surface of the upper mold so that the back surface of the core material having the inlet faces the set surface of the upper mold, and close the upper mold and the lower mold.
Next, the injection nozzle having the engagement portion formed on the tip side is lowered and inserted into the injection port of the core material, and the engagement is formed on the inner peripheral surface of the injection port or the engaged portion formed on the outer periphery of the injection port. Engaging the parts,
Thereafter, the injection nozzle is raised to bring the periphery of the injection port on the back surface of the core material into contact with the set surface of the upper mold,
Thereafter, a molten resin material is injected from the injection nozzle into a cavity formed between the upper mold and the lower mold to form a resin layer, and the resin layer and the core material are integrally molded. A method for molding a resin molded body, comprising obtaining a molded body.

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