JP5152264B2 - Manufacturing method of foamed resin molded product - Google Patents

Description

  The present invention relates to a method for producing a foamed resin molded product, in which a foamed resin molded material is filled into a cavity inside a mold by compressed air, and the filled foamed resin molded material is heated and expanded to mold a foamed resin molded product.

  Conventionally, as a method for producing this type of foamed resin molded product, each individual cavity partitioned by a partition is filled with a foamed resin molding material having a different foaming ratio, and each of the filled foamed resin molded materials is heated and expanded. A manufacturing method for molding one foamed resin molded product is known.

  FIG. 10 is a cross-sectional view showing the main structure of a foamed resin molding apparatus used in the conventional method for producing a foamed resin molded product. FIG. 11 is a cross-sectional view of a foamed resin molded product molded by the foamed resin molding apparatus shown in FIG.

  As shown in FIG. 10, the conventional foamed resin molding apparatus 30 includes a first mold 5 a, a second mold 5 b, partitions 20 and 20, a first filling apparatus 3, and a second filling apparatus 4. With. A cavity 2 is formed on the mating surfaces of the first and second molds 5a and 5b. The cavity 2 includes first cavities 2a and 2b for molding a portion with a high expansion ratio, and a second cavity 2c for molding a portion with a low expansion ratio.

  A partition 20 separates the first cavity 2a and the second cavity 2c, and the first cavity 2b and the second cavity 2c. As shown in the enlarged view surrounded by the alternate long and short dash line in the drawing, the partition 20 has a comb-teeth shape, and includes a base 21 and a plurality of teeth 22 protruding from the base.

  The first cavity 2a is connected to the tip of a feeder 3a connected to the first filling device 3 for filling the raw material A having a high expansion ratio, and the first cavity 2b is filled with the first filling. The tip of the feeder 3b connected to the device 3 is connected. Connected to the second cavity 2c is the tip of a feeder 4a connected to the second filling device 4 for filling the raw material B with a low expansion ratio.

  The raw material A and the raw material B are pre-expanded expanded polystyrene beads, respectively. Further, although not shown, the foamed resin molding apparatus 30 includes a mold opening device for opening the first and second molds 5a and 5b and a foamed resin molded product molded in the cavity 2. And a mold release device.

  Then, the raw material A is filled into the first cavities 2a and 2b by the first filling device 3 via the feeders 3a and 3b, and the raw material B is filled by the second filling device 4 via the feeder 4a and the second cavity 2c. To fill. Subsequently, the outer surface of the cavity 2 was heated with high-temperature steam, and the raw material A filled in the first cavities 2a and 2b and the raw material B filled in the second cavity 2c were respectively heated and expanded to expand. The raw materials are fused.

  Subsequently, the outer surface of the cavity 2 is cooled with cold water, the first and second molds 5a and 5b are opened with a mold opening device, and the foamed resin molded product 10 molded in the cavity 2 is released with a mold release device. Take out. As shown in FIG. 11, the foamed resin molded product 10 thus molded includes a high-magnification molded portion 6 molded in the first cavities 2a and 2b and a low-magnification molded in the second cavity 2c. The molded part 7 is integrally molded. In the foamed resin molded product 10, the strength of the low-magnification molded part 7 molded from the raw material B having a low foaming ratio is higher than that of the high-magnification molded part 6.

  As another conventional manufacturing method, after the first cavity 2a, 2b is filled with the raw material A, the comb-like partition 20 or the plate-shaped partition is removed, and then the second cavity 2c. A manufacturing method for filling the raw material B is known.

  FIG. 12 is a cross-sectional view showing the main structure of a foamed resin molding apparatus used in the manufacturing method. FIG. 13 is a cross-sectional view showing a state where a foamed resin molded product is molded in the cavity. 14 is a cross-sectional view of a foamed resin molded product molded by the foamed resin molding apparatus shown in FIG. In addition, about the same structure as the foamed resin molding apparatus shown in FIG. 10, the same code | symbol is used and the description is abbreviate | omitted.

  The foamed resin molding apparatus 40 includes plate-like partitions 41 and 41 that partition the cavities, and a piston cylinder device 42 that moves the partitions 41 back and forth between a partition position and a position that is not partitioned. Each partition 41 is attached to a piston 42a constituting the piston cylinder device 42, respectively.

  In a state where the cavities are partitioned by the partitions 41, the first filling device 3 fills the first cavities 2a and 2b with the raw material A through the feeders 3a and 3b. Subsequently, after operating the piston cylinder device 42 to retract each partition 41 from the partition position, the second filling device 4 fills the second cavity 2c with the raw material B via the feeder 4a. And the foamed resin molding 10 shown in FIG. 14 is obtained through each process of heating expansion, cooling, mold opening, and mold release.

JP-A-2002-234044 (paragraphs 11 to 21, FIGS. 1 to 4).

However, the foamed resin molded product 10 manufactured by the manufacturing method in which the cavities are separated by the comb-shaped partition 20 is used for the raw material A and the raw material B through the gap between the teeth 22 and the teeth 22 of the partition 20. The materials are fused together, but the raw materials cannot be fused at the portions where the teeth 22 existed.
Therefore, as shown in FIG. 11, gaps 11 and 11 are formed between the high-magnification molded part 6 and the low-magnification molded part 7, so that the bonding strength between the high-magnification molded part 6 and the low-magnification molded part 7 decreases. There is a problem that it ends up.

Further, in the manufacturing method of filling the second cavity 2c with the raw material B after the partition 41 is retracted from the partition position, the pressurized air for pumping the raw material B when the raw material B is filled into the second cavity 2c. As a result, the raw material A and the raw material B are stirred.
Therefore, as shown in FIG. 13, since the shape of the boundary between the first and second cavities is greatly collapsed, there is a large error in the volume of the low-magnification molding part, which is a molding part whose strength should be increased by the raw material B having a low foaming ratio There is a problem that occurs.

  Therefore, the present invention has been made to solve the above-mentioned problems, and no gap is formed at the boundary between the portions molded by the foamed resin molding material having different foaming ratios, and the strength should be increased. It is an object of the present invention to realize a method for manufacturing a foamed resin molded product that can reduce the volume error of a portion.

In order to achieve the above object, in the invention described in claim 1, the foamed resin molding material (6, 7) is filled into the cavity (2) inside the mold (5 a, 5 b) by compressed air, and the filling is performed. In the manufacturing method of a foamed resin molded product in which the foamed resin molded material is heated and expanded to mold the foamed resin molded product (8), the first cavity (2a, 2a, 2b) and a second cavity formed adjacent to the first cavity and filled with a second foamed resin molding material (B) having a different expansion ratio from the first foamed resin molding material (2c), a mold (5a, 5b), a first filling device (3) for filling the first cavity with the first foamed resin molding material by compressed air, and the second foam Resin molding material is fed by compressed air. A second filling device (4) for filling the first cavity, a partition member (8) for partitioning the first and second cavities, and a first for partitioning the partition member between the first and second cavities. And an advancing / retracting device (9) for retreating to a second position that does not partition between the first and second cavities, and the partition member is between the first and second cavities. A first filling step (S2) of filling the first cavity with the first foamed resin molding material by the first filling device when partitioned by the first filling device, and after the completion of the first filling step The second filling device fills the second cavity with the second foamed resin molding material while retracting the partition member from the first position to the second position by the advance / retreat device. A step of filling (S3), have a, wherein the second filling device (4), the supply for supplying the second foamed resin molding material (B) to said second cavity (2c) The pipe (4a) is provided, and the supply pipe is inserted through the partition member (8), and the partition member uses technical means such that the partition member advances and retreats along the inserted supply pipe. .

In the invention according to claim 2, wherein in the method for producing a foamed resin molded article according to claim 1, wherein the first and second filling device (3, 4) and the conveying unit (9) and said mold ( 5a, 5b) using technical means that are mounted on the same side.

According to a third aspect of the present invention, in the method for manufacturing a foamed resin molded product according to the first or second aspect , the foaming ratio of the second foamed resin molding material (B) is the first foamed resin molded product. A technical means is used that is lower than the expansion ratio of the material (A).

  In addition, the code | symbol in each said parenthesis shows the correspondence with the specific means as described in embodiment mentioned later.

(Effect of the invention according to claim 1)
After the first foaming resin molding material is filled into the first cavity by the first filling device, the second foaming resin molding material is put into the second cavity by the second filling device while the partition member is retracted by the advance / retreat device. Can be filled.

  In other words, the second cavity was filled with the second foamed resin molding material while gradually increasing the volume of the second cavity that was blocked by the partition member, so that the second cavity was filled. Since the second foamed resin molding material serves as a partition member, there is no possibility that the first foamed resin molding material filled in the first cavity flows into the second cavity.

Further, while gradually increasing the volume of the second cavity closed by the partition member, the second foamed resin molding material is used to fill the second cavity with the second foamed resin molding material. It is difficult for the first and second foamed resin molding materials to be agitated by the compressed air when filling the second cavity.
Therefore, the volume error of the portion molded by the second foamed resin molding material can be reduced.

In addition, since the partition member is retracted, the first and second foamed resin molding materials are not fused at the boundary between the cavities due to the presence of the partition member, so that the partition member is molded with a different foamed resin molding material. No gap is formed at the boundary between the portions.
Therefore, the joint strength between the parts molded with different foamed resin molding materials does not decrease.

The partition member is inserted with a supply pipe for supplying the second foamed resin molding material to the second cavity, and the partition member advances and retreats along the inserted supply pipe. There is no need for a guide member for guiding in the forward / backward direction.

(Effect of the invention according to claim 2 )
Since the first and second filling devices and the advance / retreat device are attached to the same side of the mold, the degree of freedom of the arrangement position when arranging the mold release device, the mold opening device, etc. on the opposite side of the mold is increased. Can do.

(Effect of the invention according to claim 3 )
Since the expansion ratio of the second foamed resin molding material is lower than the expansion ratio of the first foamed resin molding material, the strength of the portion molded in the second cavity is greater than the strength of the portion molded in the first cavity. Can also be high.

It is sectional drawing which shows a part of main part of the foamed resin molding apparatus used in the manufacturing method of the foamed resin molded product which concerns on 1st Embodiment of this invention. It is sectional drawing which shows the state with which the raw material A was filled into 1st cavity 2a, 2b. It is sectional drawing which shows the state which started filling the raw material B in the 2nd cavity 2c. It is sectional drawing which shows the state with which the raw material B was filled into the 2nd cavity 2c. It is sectional drawing of the foamed resin molded product shape | molded by the foamed resin molding apparatus 1 shown in FIG. It is a flowchart which shows the step of a manufacturing method. It is sectional drawing which shows the state with which the raw material A was filled into 1st cavity 2a, 2b. It is sectional drawing which shows the state which started filling the raw material B in the 2nd cavity 2c. It is sectional drawing which shows the state with which the raw material B was filled into the 2nd cavity 2c. It is sectional drawing which shows the main structures of the foamed resin molding apparatus used in the manufacturing method of the conventional foamed resin molded product. It is sectional drawing of the foamed resin molded product shape | molded by the foamed resin molding apparatus shown in FIG. It is sectional drawing which shows the main structures of the foaming resin molding apparatus used in the conventional manufacturing method. It is sectional drawing which shows the state by which the foamed resin molded product was shape | molded within the cavity. It is sectional drawing of the foamed resin molded product shape | molded by the foamed resin molding apparatus shown in FIG.

<First Embodiment>
A first embodiment according to the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view showing a part of a main part of a foamed resin molding apparatus used in the method for producing a foamed resin molded product according to the first embodiment. In FIG. 1, only half of the longitudinal direction of the foamed resin molding apparatus is shown. In the following embodiments, a shock absorbing material provided inside a bumper of an automobile as a foamed resin molded product will be described as a representative.

[Main configuration of foamed resin molding equipment]
First, the main configuration of the foamed resin molding apparatus will be described with reference to the drawings.
As shown in FIG. 1, a foamed resin molding apparatus 1 according to this embodiment includes a first mold 5a, a second mold 5b, a first filling apparatus 3, a second filling apparatus 4, and a slide piece. 8 and a piston cylinder device 9. A cavity 2 is formed on the mating surfaces of the first and second molds 5a and 5b. The cavity 2 is formed in a shape corresponding to a bumper of an automobile, and first cavities 2a and 2b for molding a portion with a high expansion ratio and a second cavity for molding a portion with a low expansion ratio. 2c.

  The first cavity 2a is connected to the tip of a feeder 3a connected to the first filling device 3 for filling the raw material A having a high expansion ratio, and the first cavity 2b is filled with the first filling. The tip of the feeder 3b connected to the device 3 is connected. Connected to the second cavity 2c is the tip of a feeder 4a connected to the second filling device 4 for filling the raw material B with a low expansion ratio.

  In this embodiment, the raw material A and the raw material B are each pre-expanded expanded polystyrene beads. In addition, regarding the expansion ratio, the raw material A has a high expansion ratio (for example, 12 to 15 times), and the raw material B has a low expansion ratio (for example, 5 times). Although not shown, the foamed resin molding apparatus 1 includes a mold opening device for opening the first and second molds 5a and 5b and a foamed resin molded product molded in the cavity 2. And a mold release device.

  In the first mold 5a, a slide piece 8 is provided so as to be able to advance and retreat with respect to the second cavity 2c. A portion of the slide piece 8 that is disposed in the second cavity 2c is formed in the shape of the second cavity 2c. At the rear end of the slide piece 8, a tip of a piston rod 9a provided in the piston cylinder device 9 is attached. That is, when the piston rod 9a is extended by the operation of the piston cylinder device 9, the slide piece 8 moves into the second cavity 2c, and when the piston rod 9b is retracted, the slide piece 8 moves from the inside of the second cavity 2c. Evacuate outside.

  Further, as shown in FIG. 1, the front surface 8a of the slide piece 8 is exposed to the second cavity 2c when the slide piece 8 is retracted to a position that does not partition the first and second cavities, and the second piece A part of the wall surface of the cavity 2c is formed and the second cavity 2c is closed. In addition, when the slide piece 8 advances into the second cavity 2c and partitions between the first and second cavities, the second cavity 2c is closed by the slide piece 8 (FIG. 2).

[Method for producing foamed resin molded product]
Next, a method for producing a foamed resin molded product using the above-described foamed resin molding apparatus 1 will be described with reference to the drawings.

  FIG. 2 is a cross-sectional view showing a state in which the raw material A is filled in the first cavities 2a and 2b. FIG. 3 is a cross-sectional view showing a state in which the raw material B starts to be filled in the second cavity 2c. FIG. 4 is a cross-sectional view showing a state in which the material B is filled in the second cavity 2c. FIG. 5 is a cross-sectional view of a foamed resin molded product molded by the foamed resin molding apparatus 1 shown in FIG. FIG. 6 is a flowchart showing the steps of the manufacturing method.

  First, the piston cylinder device 9 is actuated to extend the piston 9a, and the slide piece 8 is fitted into the second cavity 2c (step (hereinafter abbreviated as S) 1). Next, the first filling device 3 is operated to fill the first cavities 2a and 2b with the raw material A through the feeders 3a and 3b (S2).

  Next, the piston cylinder device 9 is operated to retract the piston 9a, and while the slide piece 8 is retracted from the second cavity 2c, the second filling device 4 is operated to supply the raw material B through the feeder 4a. 2 cavities 2c are filled (S3). At this time, since the raw material B filled in the second cavity 2c plays a role of partitioning between the first and second cavities, the raw material A filled in the first cavities 2a and 2b becomes the second cavity. There is no risk of flowing into 2c. Further, since the slide piece 8 is gradually retracted and the second cavity 2c is gradually enlarged, the raw material A and the raw material B are not easily stirred by the pressurized air that pumps the B raw material.

  Then, when the front surface 8a of the slide piece 8 coincides with one surface of the second cavity 2c, the contraction of the piston 9a is stopped. Thereby, as shown in FIG. 4, the second cavity 2 c is closed by the front surface 8 a of the slide piece 8.

  Next, the raw material A and the raw material B filled in the cavity 2 are heated and expanded (S4). At this time, since there is no partition between the first and second cavities, the raw material A and the raw material B can be fused without a gap at the boundary between the first and second cavities. Next, the cavity 2 is cooled (S5), the mold is opened (S6), and the mold is released (S7).

  Thereby, the foamed resin molded product 10 shown in FIG. 5 is obtained. As shown in the figure, the foamed resin molded product 10 manufactured by the above-described manufacturing method has no gap at the boundary between the high-magnification molded part 6 molded by the raw material A and the low-magnification molded part 7 molded by the raw material B, In addition, the shape of the boundary is straight and does not collapse.

  Therefore, if the method for manufacturing a foamed resin molded product according to the first embodiment is carried out, the volume error of the low-magnification molded portion 7 that is the portion whose strength is to be increased can be reduced. Moreover, since no gap is formed at the boundary between the high-magnification molded part 6 and the low-magnification molded part 7, the bonding strength at the boundary does not decrease. In particular, the shock absorbing material provided inside the bumper of an automobile requires high accuracy for the volume of a portion requiring high strength in order to enhance collision safety. If the manufacturing method is carried out, the demand can be met.

  Further, since the portion of the slide piece 8 that is disposed in the second cavity 2c is formed in the shape of the second cavity 2c, the raw material B is removed while the slide piece 8 is retracted from the second cavity 2c. By filling the second cavity 2c, the raw material B can be filled in the shape of the second cavity 2c.

  Further, since the second cavity 2c can be covered with the front surface 8a of the slide piece 8, it is not necessary to use a separate member for covering the second cavity 2c.

  Furthermore, since the first and second filling devices 3 and 4 are attached to the mold 5b side, the raw material supply device for supplying the raw material A and the raw material B to the first and second filling devices 3 and 4 Etc. can be arranged in the vicinity of the first and second filling devices 3 and 4, so that the raw material supply efficiency can be increased.

  Furthermore, since the piston cylinder device 9 is attached to the side of the die 5a opposite to the die 5b, the degree of freedom of the arrangement position of the piston cylinder device 9, the first and second filling devices 3 and 4 can be increased. it can.

Second Embodiment
A second embodiment according to the present invention will be described with reference to the drawings. FIG. 7 is a cross-sectional view showing a state in which the raw material A is filled in the first cavities 2a and 2b. FIG. 8 is a cross-sectional view showing a state in which the raw material B has started to be filled in the second cavity 2c. FIG. 9 is a cross-sectional view showing a state in which the material B is filled in the second cavity 2c.

  A pair of pistons 9 a are connected to the rear end of the slide piece 8. A through hole 8b is formed in the slide piece 8 in the front-rear direction. A feeder 4a for filling the material B into the second cavity 2c is inserted into the through hole 8b. The slide piece 8 moves forward and backward along the feeder 4a by the extending operation and the retracting operation of each piston 9a. That is, the feeder 4a plays the role of a guide member when the slide piece 8 moves back and forth.

  The steps of the manufacturing method are the same as those in the first embodiment. First, as shown in FIG. 7, the piston cylinder device 9 is operated to extend each piston 9a, and the slide piece 8 is fitted into the second cavity 2c (S1 in FIG. 6). Next, the first filling device 3 is operated to fill the first cavities 2a and 2b with the raw material A through the feeders 3a and 3b (S2).

  Next, as shown in FIG. 8, the piston cylinder device 9 is operated to retract each piston 9 a, and the second filling device 4 is operated while the slide piece 8 is retracted from the second cavity 2 c. The raw material B is filled into the second cavity 2c through 4a (S3). At this time, since the raw material B filled in the second cavity 2c plays a role of partitioning between the first and second cavities, the raw material A filled in the first cavities 2a and 2b becomes the second cavity. There is no risk of flowing into 2c. Further, since the slide piece 8 is gradually retracted and the second cavity 2c is gradually enlarged, the raw material A and the raw material B are not easily stirred by the pressurized air that pumps the B raw material.

  Then, when the front surface 8a of the slide piece 8 coincides with one surface of the second cavity 2c, the degeneration of each piston 9a is stopped. As a result, as shown in FIG. 9, the second cavity 2 c is closed by the front surface 8 a of the slide piece 8.

  Next, the raw material A and the raw material B filled in the cavity 2 are heated and expanded (S4). At this time, since there is no partition between the first and second cavities, the raw material A and the raw material B can be fused without a gap at the boundary between the first and second cavities. Next, the cavity 2 is cooled (S5), the mold is opened (S6), and the mold is released (S7).

  Thereby, the foamed resin molded product 10 shown in FIG. 5 is obtained. As shown in the figure, the foamed resin molded product 10 manufactured by the above-described manufacturing method has no gap at the boundary between the high-magnification molded part 6 molded by the raw material A and the low-magnification molded part 7 molded by the raw material B, In addition, the shape of the boundary is straight and does not collapse.

  Therefore, if the method for manufacturing a foamed resin molded product according to the second embodiment is implemented, the volume error of the low-magnification molded portion 7 that is the portion whose strength is to be increased can be reduced. Moreover, since no gap is formed at the boundary between the high-magnification molded part 6 and the low-magnification molded part 7, the bonding strength at the boundary does not decrease. In particular, the shock absorbing material provided inside the bumper of an automobile requires high accuracy for the volume of a portion requiring high strength in order to enhance collision safety. If the manufacturing method is carried out, the demand can be met.

  Further, since the second cavity 2c can be covered by the front surface 8a of the slide piece 8, it is not necessary to use a separate member for covering the second cavity 2c.

  Furthermore, since the first and second filling devices 3 and 4 are attached to the mold 5b side, the raw material supply device for supplying the raw material A and the raw material B to the first and second filling devices 3 and 4 Etc. can be arranged in the vicinity of the first and second filling devices 3 and 4, so that the raw material supply efficiency can be increased.

  Further, a feeder 4a for supplying the raw material B to the second cavity 2c is inserted into the slide piece 8, and the slide piece 8 advances and retreats along the inserted feeder 4a. A guide member for guiding in the forward / backward direction is not required.

  Furthermore, since the first and second filling devices 3 and 4 and the piston cylinder device 9 are attached to the mold 5b side, the arrangement when the mold opening device or the mold release device is arranged on the opposite side of the mold is arranged. The degree of freedom of position can be increased.

1 .. Foamed resin molding device, 2 .... cavity, 2a, 2b ... first cavity,
2c ··· second cavity, ··· first filling device, ··· second filling device,
5a, 5b ... Mold, 6 ... High magnification molding part, 7 ... Low magnification molding part,
8 ··· Slide piece (partition member), 9 · · Piston cylinder device (advance / retreat device),
10. Foamed resin molded product.

Claims (3)

In the method of manufacturing a foamed resin molded product, the foamed resin molding material is filled into a cavity inside the mold by compressed air, and the foamed resin molding material is heated and expanded to mold the foamed resin molded product.
A first cavity filled with a first foamed resin molding material;
A mold having a second cavity formed adjacent to the first cavity and filled with a second foamed resin molding material having a different expansion ratio than the first foamed resin molding material;
A first filling device that fills the first cavity with the first foamed resin molding material by compressed air;
A second filling device for filling the second cavity with the second foamed resin molding material by compressed air;
A partition member for partitioning the first and second cavities;
An advancing / retreating device that advances the partition member to a first position that partitions the first and second cavities and retracts the partition member to a second position that does not partition the first and second cavities; ,
A first filling step of filling the first cavity with the first foamed resin molding material by the first filling device when the first and second cavities are partitioned by the partition member; ,
After the completion of the first filling step, the second foaming resin molding material is removed by the second filling device while the partition member is retracted from the first position to the second position by the advance / retreat device. A second filling step for filling the two cavities;
I have a,
The second filling device includes a supply pipe for supplying the second foamed resin molding material to the second cavity,
The supply pipe is inserted through the partition member,
The method of manufacturing a foamed resin molded product, wherein the partition member advances and retreats along the inserted supply pipe . The method for producing a foamed resin molded article according to claim 1 , wherein the first and second filling devices and the advance / retreat device are attached to the same side of the mold. The method for producing a foamed resin molded article according to claim 1 or 2 , wherein the foaming ratio of the second foamed resin molding material is lower than the foaming ratio of the first foamed resin molding material.

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